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Sample records for allocation model sam

  1. SAM Photovoltaic Model Technical Reference

    SciTech Connect

    Gilman, P.

    2015-05-27

    This manual describes the photovoltaic performance model in the System Advisor Model (SAM). The U.S. Department of Energy’s National Renewable Energy Laboratory maintains and distributes SAM, which is available as a free download from https://sam.nrel.gov. These descriptions are based on SAM 2015.1.30 (SSC 41).

  2. System Advisor Model, SAM 2014.1.14: General Description

    SciTech Connect

    Blair, N.; Dobos, A. P.; Freeman, J.; Neises, T.; Wagner, M.; Ferguson, T.; Gilman, P.; Janzou, S.

    2014-02-01

    This document describes the capabilities of the U.S. Department of Energy and National Renewable Energy Laboratory's System Advisor Model (SAM), Version 2013.9.20, released on September 9, 2013. SAM is a computer model that calculates performance and financial metrics of renewable energy systems. Project developers, policy makers, equipment manufacturers, and researchers use graphs and tables of SAM results in the process of evaluating financial, technology, and incentive options for renewable energy projects. SAM simulates the performance of photovoltaic, concentrating solar power, solar water heating, wind, geothermal, biomass, and conventional power systems. The financial model can represent financial structures for projects that either buy and sell electricity at retail rates (residential and commercial) or sell electricity at a price determined in a power purchase agreement (utility). SAM's advanced simulation options facilitate parametric and sensitivity analyses, and statistical analysis capabilities are available for Monte Carlo simulation and weather variability (P50/P90) studies. SAM can also read input variables from Microsoft Excel worksheets. For software developers, the SAM software development kit (SDK) makes it possible to use SAM simulation modules in their applications written in C/C++, C#, Java, Python, and MATLAB. NREL provides both SAM and the SDK as free downloads at http://sam.nrel.gov. Technical support and more information about the software are available on the website.

  3. Technical Manual for the SAM Physical Trough Model

    SciTech Connect

    Wagner, M. J.; Gilman, P.

    2011-06-01

    NREL, in conjunction with Sandia National Lab and the U.S Department of Energy, developed the System Advisor Model (SAM) analysis tool for renewable energy system performance and economic analysis. This paper documents the technical background and engineering formulation for one of SAM's two parabolic trough system models in SAM. The Physical Trough model calculates performance relationships based on physical first principles where possible, allowing the modeler to predict electricity production for a wider range of component geometries than is possible in the Empirical Trough model. This document describes the major parabolic trough plant subsystems in detail including the solar field, power block, thermal storage, piping, auxiliary heating, and control systems. This model makes use of both existing subsystem performance modeling approaches, and new approaches developed specifically for SAM.

  4. Wind Technology Modeling Within the System Advisor Model (SAM) (Poster)

    SciTech Connect

    Blair, N.; Dobos, A.; Ferguson, T.; Freeman, J.; Gilman, P.; Whitmore, J.

    2014-05-01

    This poster provides detail for implementation and the underlying methodology for modeling wind power generation performance in the National Renewable Energy Laboratory's (NREL's) System Advisor Model (SAM). SAM's wind power model allows users to assess projects involving one or more large or small wind turbines with any of the detailed options for residential, commercial, or utility financing. The model requires information about the wind resource, wind turbine specifications, wind farm layout (if applicable), and costs, and provides analysis to compare the absolute or relative impact of these inputs. SAM is a system performance and economic model designed to facilitate analysis and decision-making for project developers, financers, policymakers, and energy researchers. The user pairs a generation technology with a financing option (residential, commercial, or utility) to calculate the cost of energy over the multi-year project period. Specifically, SAM calculates the value of projects which buy and sell power at retail rates for residential and commercial systems, and also for larger-scale projects which operate through a power purchase agreement (PPA) with a utility. The financial model captures complex financing and rate structures, taxes, and incentives.

  5. System Advisor Model, SAM 2011.12.2: General Description

    SciTech Connect

    Gilman, P.; Dobos, A.

    2012-02-01

    This document describes the capabilities of the U.S. Department of Energy and National Renewable Energy Laboratory's System Advisor Model (SAM), Version 2011.12.2, released on December 2, 2011. SAM is software that models the cost and performance of renewable energy systems. Project developers, policy makers, equipment manufacturers, and researchers use graphs and tables of SAM results in the process of evaluating financial, technology, and incentive options for renewable energy projects. SAM simulates the performance of solar, wind, geothermal, biomass, and conventional power systems. The financial model can represent financing structures for projects that either buy and sell electricity at retail rates (residential and commercial) or sell electricity at a price determined in a power purchase agreement (utility). Advanced analysis options facilitate parametric, sensitivity, and statistical analyses, and allow for interfacing SAM with Microsoft Excel or with other computer programs. SAM is available as a free download at http://sam.nrel.gov. Technical support and more information about the software are available on the website.

  6. Technoeconomic Modeling of Battery Energy Storage in SAM

    SciTech Connect

    DiOrio, Nicholas; Dobos, Aron; Janzou, Steven; Nelson, Austin; Lundstrom, Blake

    2015-09-01

    Detailed comprehensive lead-acid and lithium-ion battery models have been integrated with photovoltaic models in an effort to allow System Advisor Model (SAM) to offer the ability to predict the performance and economic benefit of behind the meter storage. In a system with storage, excess PV energy can be saved until later in the day when PV production has fallen, or until times of peak demand when it is more valuable. Complex dispatch strategies can be developed to leverage storage to reduce energy consumption or power demand based on the utility rate structure. This document describes the details of the battery performance and economic models in SAM.

  7. The fSAM Model of False Recall

    ERIC Educational Resources Information Center

    Kimball, Daniel R.; Smith, Troy A.; Kahana, Michael J.

    2007-01-01

    The authors report a new theory of false memory building upon existing associative memory models and implemented in fSAM, the first fully specified quantitative model of false recall. Participants frequently intrude unstudied critical words while recalling lists comprising their strongest semantic associates but infrequently produce other…

  8. Technical Manual for the SAM Biomass Power Generation Model

    SciTech Connect

    Jorgenson, J.; Gilman, P.; Dobos, A.

    2011-09-01

    This technical manual provides context for the implementation of the biomass electric power generation performance model in the National Renewable Energy Laboratory's (NREL's) System Advisor Model (SAM). Additionally, the report details the engineering and scientific principles behind the underlying calculations in the model. The framework established in this manual is designed to give users a complete understanding of behind-the-scenes calculations and the results generated.

  9. Introducing the aerosol-climate model MAECHAM5-SAM2

    NASA Astrophysics Data System (ADS)

    Hommel, R.; Timmreck, C.; Graf, H. F.

    2009-04-01

    We are presenting a new global aerosol model MAECHAM5-SAM2 to study the aerosol dynamics in the UTLS under background and volcanic conditions. The microphysical core modul SAM2 treats the formation, the evolution and the transport of stratospheric sulphuric acid aerosol. The aerosol size distribution and the weight percentage of the sulphuric acid solution is calculated dependent on the concentrations of H2SO4 and H2O, their vapor pressures, the atmospheric temperature and pressure. The fixed sectional method is used to resolve an aerosol distribution between 1 nm and 2.6 micron in particle radius. Homogeneous nucleation, condensation and evaporation, coagulation, water-vapor growth, sedimentation and sulphur chemistry are included. The module is applied in the middle-atmosphere MAECHAM5 model, resolving the atmosphere up to 0.01 hPa (~80 km) in 39 layers. It is shown here that MAECHAM5-SAM2 well represents in-situ measured size distributions of stratospheric background aerosol in the northern hemisphere mid-latitudes. Distinct differences can be seen when derived integrated aerosol parameters (surface area, effective radius) are compared with aerosol climatologies based on the SAGE II satellite instrument (derived by the University of Oxford and the NASA AMES laboratory). The bias between the model and the SAGE II data increases as the moment of the aerosol size distribution decreases. Thus the modeled effective radius show the strongest bias, followed by the aerosol surface area density. Correspondingly less biased are the higher moments volume area density and the mass density of the global stratospheric aerosol coverage. This finding supports the key finding No. 2 of the SPARC Assessment of Stratospheric Aerosol Properties (2006), where it was shown that during periods of very low aerosol load in the stratosphere, the consistency between in-situ and satellite measurements, which exist in a volcanically perturbed stratosphere, breaks down and significant

  10. A Spatial Analysis and Modeling System (SAMS) for environment management

    NASA Technical Reports Server (NTRS)

    Stetina, Fran; Hill, John; Chan, Paul; Jaske, Robert; Rochon, Gilbert

    1993-01-01

    This is a proposal to develop a uniform global environmental data gathering and distribution system to support the calibration and validation of remotely sensed data. SAMS is based on an enhanced version of FEMA's Integrated Emergency Management Information Systems and the Department of Defense's Air land Battlefield Environment Software Systems. This system consists of state-of-the-art graphics and visualization techniques, simulation models, database management and expert systems for conducting environmental and disaster preparedness studies. This software package will be integrated into various Landsat and UNEP-GRID stations which are planned to become direct readout stations during the EOS (Earth Observing System) timeframe. This system would be implemented as a pilot program to support the Tropical Rainfall Measuring Mission (TRMM). This will be a joint NASA-FEMA-University-Industry project.

  11. A Spatial Analysis and Modeling System (SAMS) for environment management

    NASA Technical Reports Server (NTRS)

    Vermillion, Charles H.; Stetina, Fran; Hill, John; Chan, Paul; Jaske, Robert; Rochon, Gilbert

    1992-01-01

    This is a proposal to develop a uniform global environmental data gathering and distribution system to support the calibration and validation of remotely sensed data. SAMS is based on an enhanced version of FE MA's Integrated Emergency Management Information Systems and the Department of Defense's Air Land Battlefield Environment Software Systems. This system consists of state-of-the-art graphics and visualization techniques, simulation models, database management and expert systems for conducting environmental and disaster preparedness studies. This software package will be integrated into various Landsat and UNEP-GRID stations which are planned to become direct readout stations during the EOS timeframe. This system would be implemented as a pilot program to support the Tropical Rainfall Measuring Mission (TRMM). This will be a joint NASA-FEMA-University-Industry project.

  12. Minority Transportation Expenditure Allocation Model

    1993-04-12

    MITRAM (Minority TRansportation expenditure Allocation Model) can project various transportation related attributes of minority (Black and Hispanic) and majority (white) populations. The model projects vehicle ownership, vehicle miles of travel, workers, new car and on-road fleet fuel economy, amount and share of household income spent on gasoline, and household expenditures on public transportation and taxis. MITRAM predicts reactions to sustained fuel price changes for up to 10 years after the change.

  13. The fSAM Model of False Recall

    PubMed Central

    Kimball, Daniel R.; Smith, Troy A.; Kahana, Michael J.

    2009-01-01

    The authors report a new theory of false memory building upon existing associative memory models and implemented in fSAM, the first fully specified quantitative model of false recall. Participants frequently intrude unstudied critical words while recalling lists comprising their strongest semantic associates but infrequently produce other extralist and prior-list intrusions. The authors developed the theory by simulating recall of such lists, using factorial combinations of semantic mechanisms operating at encoding, retrieval, or both stages. During encoding, unstudied words' associations to list context were strengthened in proportion to their strength of semantic association either to each studied word or to all co-rehearsed words. During retrieval, words received preference in proportion to their strength of semantic association to the most recently recalled single word or multiple words. The authors simulated all intrusion types and veridical recall for lists varying in semantic association strength among studied and critical words from the same and different lists. Multiplicative semantic encoding and retrieval mechanisms performed well in combination. Using such combined mechanisms, the authors also simulated several core findings from the Deese–Roediger–McDermott paradigm literature, including developmental patterns, specific list effects, association strength effects, and true–false correlations. These results challenge existing false-memory theories. PMID:17907869

  14. Molten Salt Power Tower Cost Model for the System Advisor Model (SAM)

    SciTech Connect

    Turchi, C. S.; Heath, G. A.

    2013-02-01

    This report describes a component-based cost model developed for molten-salt power tower solar power plants. The cost model was developed by the National Renewable Energy Laboratory (NREL), using data from several prior studies, including a contracted analysis from WorleyParsons Group, which is included herein as an Appendix. The WorleyParsons' analysis also estimated material composition and mass for the plant to facilitate a life cycle analysis of the molten salt power tower technology. Details of the life cycle assessment have been published elsewhere. The cost model provides a reference plant that interfaces with NREL's System Advisor Model or SAM. The reference plant assumes a nominal 100-MWe (net) power tower running with a nitrate salt heat transfer fluid (HTF). Thermal energy storage is provided by direct storage of the HTF in a two-tank system. The design assumes dry-cooling. The model includes a spreadsheet that interfaces with SAM via the Excel Exchange option in SAM. The spreadsheet allows users to estimate the costs of different-size plants and to take into account changes in commodity prices. This report and the accompanying Excel spreadsheet can be downloaded at https://sam.nrel.gov/cost.

  15. Parabolic Trough Reference Plant for Cost Modeling with the Solar Advisor Model (SAM)

    SciTech Connect

    Turchi, C.

    2010-07-01

    This report describes a component-based cost model developed for parabolic trough solar power plants. The cost model was developed by the National Renewable Energy Laboratory (NREL), assisted by WorleyParsons Group Inc., for use with NREL's Solar Advisor Model (SAM). This report includes an overview and explanation of the model, two summary contract reports from WorleyParsons, and an Excel spreadsheet for use with SAM. The cost study uses a reference plant with a 100-MWe capacity and six hours of thermal energy storage. Wet-cooling and dry-cooling configurations are considered. The spreadsheet includes capital and operating cost by component to allow users to estimate the impact of changes in component costs.

  16. Application of the self-assembled monolayer (SAM) model to dithiophosphate and dithiocarbamate engine wear inhibitors

    SciTech Connect

    Zhou, Y.; Jiang, S.; Cagin, T.; Yamaguchi, E.S.; Frazier, R.; Ho, A.; Tang, Y.; Goddard, W.A. III

    2000-03-23

    In previous studies of dithiophosphate [TP=S{sub 2}P(OR){sub 2}] wear inhibitors bound to an oxidized iron surface, it was found that the cohesive energy of the self-assembled monolayers (SAM) for DTP molecules with various organic R groups correlate with the wear inhibition observed in full engine experiments. In this paper the calculations are expanded to consider dynamics at 500 K and the SAM model is used to predict new candidates for wear inhibitors. Using molecular dynamics (MD) simulations show that the SAM has one DTP per two surface Fe sites of iron oxide. At this coverage the cohesive energy of the SAM at 500 K is in the sequence 2-alkyl > 1-alkyl > aryl, which again correlates with wear inhibitor performance in engine wear tests. Dithiocarbamates are selected as the best candidate to supplement DTP.A number of possible alkyl substitutions for DTC were considered. The SAM model suggests that iC{sub 5} and nC{sub 3} are the best candidates, followed closely by iC{sub 3}.

  17. Construct Validation of the Louisiana School Analysis Model (SAM) Instructional Staff Questionnaire

    ERIC Educational Resources Information Center

    Bray-Clark, Nikki; Bates, Reid

    2005-01-01

    The purpose of this study was to validate the Louisiana SAM Instructional Staff Questionnaire, a key component of the Louisiana School Analysis Model. The model was designed as a comprehensive evaluation tool for schools. Principle axis factoring with oblique rotation was used to uncover the underlying structure of the SISQ. (Contains 1 table.)

  18. Linear modelling of attentional resource allocation

    NASA Technical Reports Server (NTRS)

    Pierce, B.

    1978-01-01

    Eight subjects time-shared performance of two compensatory tracking tasks under conditions when both were of constant difficulty, and when the control order of one task (designated primary) was varied over time within a trial. On line performance feedback was presented on half of the trials. The data are interpreted in terms of a linear model of the operator's attention allocation system, and suggest that this allocation is strongly suboptimal. Furthermore, the limitations in reallocating attentional resources between tasks, in response to difficulty fluctuations were not reduced by augmented performance feedback. Some characteristics of the allocation system are described, and reasons for its limitations suggested.

  19. Case Studies Comparing System Advisor Model (SAM) Results to Real Performance Data: Preprint

    SciTech Connect

    Blair, N.; Dobos, A.; Sather, N.

    2012-06-01

    NREL has completed a series of detailed case studies comparing the simulations of the System Advisor Model (SAM) and measured performance data or published performance expectations. These case studies compare PV measured performance data with simulated performance data using appropriate weather data. The measured data sets were primarily taken from NREL onsite PV systems and weather monitoring stations.

  20. Integration, Validation, and Application of a PV Snow Coverage Model in SAM

    SciTech Connect

    Ryberg, David; Freeman, Janine

    2015-09-01

    Due to the increasing deployment of PV systems in snowy climates, there is significant interest in a method capable of estimating PV losses resulting from snow coverage that has been verified for a wide variety of system designs and locations. A scattering of independent snow coverage models have been developed over the last 15 years; however, there has been very little effort spent on verifying these models beyond the system design and location on which they were based. Moreover, none of the major PV modeling software products have incorporated any of these models into their workflow. In response to this deficiency, we have integrated the methodology of the snow model developed in the paper by Marion et al. [1] into the National Renewable Energy Laboratory's (NREL) System Advisor Model (SAM). In this work we describe how the snow model is implemented in SAM and discuss our demonstration of the model's effectiveness at reducing error in annual estimations for two PV arrays. Following this, we use this new functionality in conjunction with a long term historical dataset to estimate average snow losses across the United States for a typical PV system design. The open availability of the snow loss estimation capability in SAM to the PV modeling community, coupled with our results of the nation-wide study, will better equip the industry to accurately estimate PV energy production in areas affected by snowfall.

  1. Evolution of SAM in an enhanced model for Monitoring WLCG services

    NASA Astrophysics Data System (ADS)

    Collados, David; Shade, John; Traylen (Cern, Steve; Imamagic (Srce, Emir

    2010-04-01

    It is four years now since the first prototypes of tools and tests started to monitor the Worldwide LHC Computing Grid (WLCG) services. One of these tools is the Service Availability Monitoring (SAM) framework, which superseded the SFT tool, and has become a keystone for the monthly WLCG availability and reliability computations. During this time, the grid has evolved into a robust, production-level infrastructure, in no small part thanks to the extensive monitoring infrastructure which includes testing, visualization and reporting. Experience gained with monitoring has led to emerging grid monitoring standards, and provided valuable input for the Operations Automation Strategy aimed at the regionalization of monitoring services. This change in scope, together with an ever-increasing number of services and infrastructures, make enhancements in the architecture of existing monitoring tools a necessity. This paper describes the present architecture of SAM, an enhanced and distributed model for monitoring WLCG services, and the required changes in SAM to adopt this new model inside the EGEE-III project.

  2. Parabolic Trough Collector Cost Update for the System Advisor Model (SAM)

    SciTech Connect

    Kurup, Parthiv; Turchi, Craig S.

    2015-11-01

    This report updates the baseline cost for parabolic trough solar fields in the United States within NREL's System Advisor Model (SAM). SAM, available at no cost at https://sam.nrel.gov/, is a performance and financial model designed to facilitate decision making for people involved in the renewable energy industry. SAM is the primary tool used by NREL and the U.S. Department of Energy (DOE) for estimating the performance and cost of concentrating solar power (CSP) technologies and projects. The study performed a bottom-up build and cost estimate for two state-of-the-art parabolic trough designs -- the SkyTrough and the Ultimate Trough. The SkyTrough analysis estimated the potential installed cost for a solar field of 1500 SCAs as $170/m2 +/- $6/m2. The investigation found that SkyTrough installed costs were sensitive to factors such as raw aluminum alloy cost and production volume. For example, in the case of the SkyTrough, the installed cost would rise to nearly $210/m2 if the aluminum alloy cost was $1.70/lb instead of $1.03/lb. Accordingly, one must be aware of fluctuations in the relevant commodities markets to track system cost over time. The estimated installed cost for the Ultimate Trough was only slightly higher at $178/m2, which includes an assembly facility of $11.6 million amortized over the required production volume. Considering the size and overall cost of a 700 SCA Ultimate Trough solar field, two parallel production lines in a fully covered assembly facility, each with the specific torque box, module and mirror jigs, would be justified for a full CSP plant.

  3. Resource allocation models of auditory working memory.

    PubMed

    Joseph, Sabine; Teki, Sundeep; Kumar, Sukhbinder; Husain, Masud; Griffiths, Timothy D

    2016-06-01

    Auditory working memory (WM) is the cognitive faculty that allows us to actively hold and manipulate sounds in mind over short periods of time. We develop here a particular perspective on WM for non-verbal, auditory objects as well as for time based on the consideration of possible parallels to visual WM. In vision, there has been a vigorous debate on whether WM capacity is limited to a fixed number of items or whether it represents a limited resource that can be allocated flexibly across items. Resource allocation models predict that the precision with which an item is represented decreases as a function of total number of items maintained in WM because a limited resource is shared among stored objects. We consider here auditory work on sequentially presented objects of different pitch as well as time intervals from the perspective of dynamic resource allocation. We consider whether the working memory resource might be determined by perceptual features such as pitch or timbre, or bound objects comprising multiple features, and we speculate on brain substrates for these behavioural models. This article is part of a Special Issue entitled SI: Auditory working memory. PMID:26835560

  4. Resource Allocation Models and Accountability: A Jamaican Case Study

    ERIC Educational Resources Information Center

    Nkrumah-Young, Kofi K.; Powell, Philip

    2008-01-01

    Higher education institutions (HEIs) may be funded privately, by the state or by a mixture of the two. Nevertheless, any state financing of HE necessitates a mechanism to determine the level of support and the channels through which it is to be directed; that is, a resource allocation model. Public funding, through resource allocation models,…

  5. Senescence-accelerated mouse (SAM): a novel murine model of senescence.

    PubMed

    Takeda, T; Hosokawa, M; Higuchi, K

    1997-01-01

    The Senescence-Accelerated Mouse (SAM) has been under development by our research team at Kyoto University since 1970 through the selective inbreeding of the AKR/J strain of mice donated by the Jackson Laboratory in 1968, based on a graded score for senescence, life span, and pathologic phenotype. At present, there are 12 lines of SAM: nine senescence-prone inbred strains (SAMP) including SAMP1, SAMP2, SAMP3, SAMP6, SAMP7, SAMP8, SAMP9, SAMP10, and SAMP11; and three senescence-resistant inbred strains (SAMR) including SAMR1, SAMR4, and SAMR5. Data from survival curves, Gompertzian function, and grading score of senescence, together with growth patterns of body weight of these SAMP and SAMR, revealed that the characteristic feature of aging common to all SAMP mice is "accelerated senescence;" early onset and irreversible advance of senescence manifested by several signs and gross lesions such as the loss of normal behavior, various skin lesions, increased lordokyphosis, etc., after a period of normal development. In the course of SAM development, it became evident that SAMP strains manifest various pathologic phenotypes that are characteristic enough to differentiate the SAM strains. The genetic background and significance of SAM development are discussed. PMID:9088907

  6. Senescence-accelerated mouse (SAM) with special references to neurodegeneration models, SAMP8 and SAMP10 mice.

    PubMed

    Takeda, Toshio

    2009-04-01

    The SAM strains, a group of related inbred strains consisting of senescence-prone inbred strains (SAMP) and senescence-resistant inbred strains (SAMR), have been successfully developed by selective inbreeding of the AKR/J strain of mice donated by the Jackson laboratory in 1968. The characteristic feature of aging common to the SAMP and SAMR is accelerated senescence and normal aging, respectively. Furthermore, SAMP and SAMR strains of mice manifest various pathobiological phenotypes spontaneously. Among SAMP strains, SAMP8 and SAMP10 mice show age-related behavioral deterioration such as deficits in learning and memory, emotional disorders (reduced anxiety-like behavior and depressive behavior) and altered circadian rhythm associated with certain pathological, biochemical and pharmacological changes. Here, the previous and recent literature on SAM mice are reviewed with an emphasis on SAMP8 and SAMP10 mice. A spontaneous model like SAM with distinct advantages over the gene-modified model is hoped by investigators to be used more widely as a biogerontological resource to explore the etiopathogenesis of accelerated senescence and neurodegenerative disorders. PMID:19199030

  7. Senescence-accelerated mouse (SAM) as an animal model of senile dementia: pharmacological, neurochemical and molecular biological approach.

    PubMed

    Okuma, Y; Nomura, Y

    1998-12-01

    To elucidate the fundamental mechanism of age-related deficiencies of learning and to develop effective drugs for intervention in age-related diseases such as learning dysfunctions, pertinent animal models that have characteristics closely similar to human dysfunctions should be established. SAM (senescence-accelerated mouse) has been established as a murine model of the SAM strains, groups of related inbred strains including nine strains of accelerated senescence-prone, short-lived mice (SAMP) and three strains of accelerated senescence-resistant, long-lived mice (SAMR). SAMP-strain mice show relatively strain-specific age-associated phenotypic pathologies such as shortened life span and early manifestation of senescence. Among the SAMP-strain mice, SAMP8 mice show an age-related deterioration in learning ability. Here, the neuropathological, neurochemical and pharmacological features of SAM are reported, especially for SAMP8. Moreover, the effects of several drugs on the biochemical and behavioral alterations in SAMP8 and the etiologic manifestation of accelerated senescence are also discussed. PMID:9920195

  8. A model for analysis of TDA budget allocation

    NASA Technical Reports Server (NTRS)

    Remer, D. S.; Buchanan, H. R.

    1994-01-01

    There is an ever-increasing need to achieve greater efficiency in the operation of the Deep Space Network (DSN), i.e., increased productivity at reduced cost. One of the tools used in the course of a planning workshop on this subject was a methodology for budget allocation applicable to long-range planning. This article presents a model for analysis of the TDA budget allocation. For the 1994 through 1999 period, the percentage of the total TDA budget allocated to capacity and capability is being cut in half, whereas the percentage spent on efficiency of delivery will be increasing.

  9. Tracking the MSL-SAM methane detection source location Through Mars Regional Atmospheric Modeling System (MRAMS)

    NASA Astrophysics Data System (ADS)

    Pla-García, Jorge

    2016-04-01

    1. Introduction: The putative in situ detection of methane by Sample Analysis at Mars (SAM) instrument suite on Curiosi-ty at Gale crater has garnered significant attention because of the potential implications for the presence of geological methane sources or indigenous Martian organisms [1, 2]. SAM reported detection of back-ground levels of atmospheric methane of mean value 0.69±0.25 parts per billion by volume (ppbv) at the 95% confidence interval (CI). Additionally, in four sequential measurements spanning a 60-sol period, SAM observed elevated levels of methane of 7.2±2.1 ppbv (95% CI), implying that Mars is episodically producing methane from an additional unknown source. There are many major unresolved questions regard-ing this detection: 1) What are the potential sources of the methane release? 2) What causes the rapid decrease in concentration? and 3) Where is the re-lease location? 4) How spatially extensive is the re-lease? 5) For how long is CH4 released? Regarding the first question, the source of methane, is so far not identified. It could be related with geo-logical process like methane release from clathrates [3], serpentinisation [4] and volcanism [5]; or due to biological activity from methanogenesis [6]. To answer the second question, the rapid decrease in concentration, it is important to note that the photo-chemical lifetime of methane is of order 100 years, much longer than the atmospheric mixing time scale, and thus the gas should tend to be well mixed except near a source or shortly after an episodic release. The observed spike of 7 ppb from the background of <1 ppb, and then the rapid return to the background lev-el could be due to a sink (destruction) or due to at-mospheric mixing. A wind mediated erosion process of ordinary quartz crystals was proposed to produce activated quartz grains, which sequester methane by forming covalent Si-C bonds. If this process is op-erational on Mars today, which some recent prelimi-nary studies on

  10. Tracking the MSL-SAM methane detection source location Through Mars Regional Atmospheric Modeling System (MRAMS)

    NASA Astrophysics Data System (ADS)

    Pla-García, Jorge

    2016-04-01

    1. Introduction: The putative in situ detection of methane by Sample Analysis at Mars (SAM) instrument suite on Curiosi-ty at Gale crater has garnered significant attention because of the potential implications for the presence of geological methane sources or indigenous Martian organisms [1, 2]. SAM reported detection of back-ground levels of atmospheric methane of mean value 0.69±0.25 parts per billion by volume (ppbv) at the 95% confidence interval (CI). Additionally, in four sequential measurements spanning a 60-sol period, SAM observed elevated levels of methane of 7.2±2.1 ppbv (95% CI), implying that Mars is episodically producing methane from an additional unknown source. There are many major unresolved questions regard-ing this detection: 1) What are the potential sources of the methane release? 2) What causes the rapid decrease in concentration? and 3) Where is the re-lease location? 4) How spatially extensive is the re-lease? 5) For how long is CH4 released? Regarding the first question, the source of methane, is so far not identified. It could be related with geo-logical process like methane release from clathrates [3], serpentinisation [4] and volcanism [5]; or due to biological activity from methanogenesis [6]. To answer the second question, the rapid decrease in concentration, it is important to note that the photo-chemical lifetime of methane is of order 100 years, much longer than the atmospheric mixing time scale, and thus the gas should tend to be well mixed except near a source or shortly after an episodic release. The observed spike of 7 ppb from the background of <1 ppb, and then the rapid return to the background lev-el could be due to a sink (destruction) or due to at-mospheric mixing. A wind mediated erosion process of ordinary quartz crystals was proposed to produce activated quartz grains, which sequester methane by forming covalent Si-C bonds. If this process is op-erational on Mars today, which some recent prelimi-nary studies on

  11. A Model for Resource Allocation Using Operational Knowledge Assets

    ERIC Educational Resources Information Center

    Andreou, Andreas N.; Bontis, Nick

    2007-01-01

    Purpose: The paper seeks to develop a business model that shows the impact of operational knowledge assets on intellectual capital (IC) components and business performance and use the model to show how knowledge assets can be prioritized in driving resource allocation decisions. Design/methodology/approach: Quantitative data were collected from 84…

  12. In the interests of time: improving HIV allocative efficiency modelling via optimal time-varying allocations

    PubMed Central

    Shattock, Andrew J; Kerr, Cliff C; Stuart, Robyn M; Masaki, Emiko; Fraser, Nicole; Benedikt, Clemens; Gorgens, Marelize; Wilson, David P; Gray, Richard T

    2016-01-01

    Introduction International investment in the response to HIV and AIDS has plateaued and its future level is uncertain. With many countries committed to ending the epidemic, it is essential to allocate available resources efficiently over different response periods to maximize impact. The objective of this study is to propose a technique to determine the optimal allocation of funds over time across a set of HIV programmes to achieve desirable health outcomes. Methods We developed a technique to determine the optimal time-varying allocation of funds (1) when the future annual HIV budget is pre-defined and (2) when the total budget over a period is pre-defined, but the year-on-year budget is to be optimally determined. We use this methodology with Optima, an HIV transmission model that uses non-linear relationships between programme spending and associated programmatic outcomes to quantify the expected epidemiological impact of spending. We apply these methods to data collected from Zambia to determine the optimal distribution of resources to fund the right programmes, for the right people, at the right time. Results and discussion Considering realistic implementation and ethical constraints, we estimate that the optimal time-varying redistribution of the 2014 Zambian HIV budget between 2015 and 2025 will lead to a 7.6% (7.3% to 7.8%) decrease in cumulative new HIV infections compared with a baseline scenario where programme allocations remain at 2014 levels. This compares to a 5.1% (4.6% to 5.6%) reduction in new infections using an optimal allocation with constant programme spending that recommends unrealistic programmatic changes. Contrasting priorities for programme funding arise when assessing outcomes for a five-year funding period over 5-, 10- and 20-year time horizons. Conclusions Countries increasingly face the need to do more with the resources available. The methodology presented here can aid decision-makers in planning as to when to expand or contract

  13. Allocating the Book Budget: A Model

    ERIC Educational Resources Information Center

    Kohut, Joseph D.

    1974-01-01

    Inflation is currently affecting library book budgets, particularly the acquisition of serials. This model would balance the purchase of serials against the purchase of monographs by individual funding units within the academic library. Consideration is given to inflation as a cost factor. The model is applied to a specific example. (Author/LS)

  14. Error rate information in attention allocation pilot models

    NASA Technical Reports Server (NTRS)

    Faulkner, W. H.; Onstott, E. D.

    1977-01-01

    The Northrop urgency decision pilot model was used in a command tracking task to compare the optimized performance of multiaxis attention allocation pilot models whose urgency functions were (1) based on tracking error alone, and (2) based on both tracking error and error rate. A matrix of system dynamics and command inputs was employed, to create both symmetric and asymmetric two axis compensatory tracking tasks. All tasks were single loop on each axis. Analysis showed that a model that allocates control attention through nonlinear urgency functions using only error information could not achieve performance of the full model whose attention shifting algorithm included both error and error rate terms. Subsequent to this analysis, tracking performance predictions for the full model were verified by piloted flight simulation. Complete model and simulation data are presented.

  15. SECURITY MODELING FOR MARITIME PORT DEFENSE RESOURCE ALLOCATION

    SciTech Connect

    Harris, S.; Dunn, D.

    2010-09-07

    Redeployment of existing law enforcement resources and optimal use of geographic terrain are examined for countering the threat of a maritime based small-vessel radiological or nuclear attack. The evaluation was based on modeling conducted by the Savannah River National Laboratory that involved the development of options for defensive resource allocation that can reduce the risk of a maritime based radiological or nuclear threat. A diverse range of potential attack scenarios has been assessed. As a result of identifying vulnerable pathways, effective countermeasures can be deployed using current resources. The modeling involved the use of the Automated Vulnerability Evaluation for Risks of Terrorism (AVERT{reg_sign}) software to conduct computer based simulation modeling. The models provided estimates for the probability of encountering an adversary based on allocated resources including response boats, patrol boats and helicopters over various environmental conditions including day, night, rough seas and various traffic flow rates.

  16. ReefSAM - Reef Sedimentary Accretion Model: A new 3D coral reef evolution model/simulator

    NASA Astrophysics Data System (ADS)

    Barrett, Samuel; Webster, Jody

    2013-04-01

    Coral reefs show characteristic morphological patterns (e.g. coral dominated margins with detrital carbonate dominated lagoons/back-reef) and temporal development (e.g. Hopley et al. 2007). While the processes which lead to predictable patterns on a range of scales have been discussed qualitatively, a full quantitative understanding of the range of processes and parameters involved requires modelling. Previous attempts to model complex Holocene reef systems (i.e. One Tree Reef, GBR - Barrett and Webster 2012) using a carbonate stratigraphic forward model (Carbonate3D - Warrlich et al. 2002) identified a number of important but unsimulated processes and potential model improvements. ReefSAM has been written from scratch in Matlab using these findings and experiences from using Carbonate3D. It simulates coralgal accretion and carbonate sand production and transport. Specific improvements include: 1. a more complex hydrodynamic model based on wave refraction and incorporating vertical (depth) and lateral (substrate dependent) variations in transport energy and erosion. 2. a complex reef growth model incorporating depth, wave energy/turbidity and substrate composition. 3. Paleo-water depth, paleo-wave energy and bio-zone (combination of paleo-water depth and wave energy) model outputs allowing coralgal habitat changes through time and space to be simulated and compared to observational data. The model is compared to the well studied One Tree Reef - tests similar to those undertaken in Barrett and Webster 2012 with Carbonate3D are presented. Model development coincides with plans for further intensive drilling at One Tree Reef (mid 2013) providing an opportunity to test the model predictively. The model is still in active development. References: Barrett, S.J., Webster, J.M.,2012. Holocene evolution of the Great Barrier Reef: Insights from 3D numerical modelling. Sedimentary Geology 265-266, 56-71. Warrlich, G.M.D., Waltham, D.A., Bosence D.W.J., 2002. Quantifying the

  17. The SAM software system for modeling severe accidents at nuclear power plants equipped with VVER reactors on full-scale and analytic training simulators

    NASA Astrophysics Data System (ADS)

    Osadchaya, D. Yu.; Fuks, R. L.

    2014-04-01

    The architecture of the SAM software package intended for modeling beyond-design-basis accidents at nuclear power plants equipped with VVER reactors evolving into a severe stage with core melting and failure of the reactor pressure vessel is presented. By using the SAM software package it is possible to perform comprehensive modeling of the entire emergency process from the failure initiating event to the stage of severe accident involving meltdown of nuclear fuel, failure of the reactor pressure vessel, and escape of corium onto the concrete basement or into the corium catcher with retention of molten products in it.

  18. Comparing Different Model Structures for Carbon Allocation in the Community Land Model (CLM)

    NASA Astrophysics Data System (ADS)

    Montane, F.; Fox, A. M.; Arellano, A. F.; Scaven, V. L.; Alexander, M. R.; Moore, D. J.

    2015-12-01

    Quantifying the intensity of feedback mechanisms between terrestrial ecosystems and climate is a central challenge for understanding the global carbon cycle. Part of this challenge includes understanding how climate affects not only NPP, but also C allocation in different plant tissues (leaves, stem and roots) which determines the C residence time. For instance, C could be sequestered over longer time periods if changes in climate increase allocation to long-lived plant tissue (e.g. woody components) with respect to short-lived tissues (e.g. leaves). Networks of eddy covariance towers like AmeriFlux provide the infrastructure necessary to study relationships between ecosystem processes and climate forcing. We ran the Community Land Model (CLM) for six temperate forests in North America (AmeriFlux sites) using different model structures for the C allocation module: i) standard carbon allocation module in CLM, which allocates C to the stem and leaves as a dynamic function of NPP and with fixed coefficients for the rest of parameters; ii) alternative C allocation module, which allocates C to the root and stem as a dynamic function of NPP and with fixed coefficients for the rest of parameters; and iii) alternative C allocation module with fixed coefficients for all the parameters. We compare C allocation patterns and climate sensitivities betwen the different model structures and available observations for the sites. We suggest some future approaches to reduce model uncertainty in the current scheme for C allocation in CLM and its climate sensitivity.

  19. On species sampling sequences induced by residual allocation models.

    PubMed

    Rodríguez, Abel; Quintana, Fernando A

    2015-02-01

    We discuss fully Bayesian inference in a class of species sampling models that are induced by residual allocation (sometimes called stick-breaking) priors on almost surely discrete random measures. This class provides a generalization of the well-known Ewens sampling formula that allows for additional flexibility while retaining computational tractability. In particular, the procedure is used to derive the exchangeable predictive probability functions associated with the generalized Dirichlet process of Hjort (2000) and the probit stick-breaking prior of Chung and Dunson (2009) and Rodriguez and Dunson (2011). The procedure is illustrated with applications to genetics and nonparametric mixture modeling. PMID:25477705

  20. On species sampling sequences induced by residual allocation models

    PubMed Central

    Rodríguez, Abel; Quintana, Fernando A.

    2014-01-01

    We discuss fully Bayesian inference in a class of species sampling models that are induced by residual allocation (sometimes called stick-breaking) priors on almost surely discrete random measures. This class provides a generalization of the well-known Ewens sampling formula that allows for additional flexibility while retaining computational tractability. In particular, the procedure is used to derive the exchangeable predictive probability functions associated with the generalized Dirichlet process of Hjort (2000) and the probit stick-breaking prior of Chung and Dunson (2009) and Rodriguez and Dunson (2011). The procedure is illustrated with applications to genetics and nonparametric mixture modeling. PMID:25477705

  1. SAP Minutes No.2015-03 for FIFRA meeting held 9/15-17/2015. A set of scientific issues being considered by the Environmental Protection Agency regarding development of a spatial aquatic model(SAM)for pesticide risk assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    On September 15-17th, 2014, the US Environmental Protection Agency convened a public meeting of the FIFRA Scientific Advisory Panel (SAP) to address scientific issues associated with the agency’s “Development of a Spatial Aquatic Model (SAM) for Pesticide Risk Assessment”. The goal of SAM is to impr...

  2. Water Allocation Modeling of Awash River Basin, Ethiopia

    NASA Astrophysics Data System (ADS)

    Asfaw, D. H.; Berhe, F.; Melesse, A. M.

    2012-12-01

    Awash River basin is one of the twelve basins of Ethiopia which is highly utilized and the first basin to be introduced to modern agriculture. A study was conducted on water allocation modeling of Awash River basin, Ethiopia using MODSIM, a river basin management decision support system (DSS) designed as a computer-aided tool for developing improved basin wide planning. This study was conducted to analyze the water balance of the Awash basin under different levels of irrigation development and also determine the water allocation in the Upper, Middle and Lower Valleys in the basin. Awash basin includes Koka Dam and two dams under completion: Kessem and Tendaho Reservoirs. Four scenarios were set: Scenario I-present withdrawal rate in the basin; Scenario II-Scenario I plus Downstream Tendaho Dam Operational; Scenario III-Scenario II plus expansion of middle valley farms and Kessem Dam Operational; and Scenario IV-Scenario III plus additional expansion in the middle valley. Analysis of flow records within the basin was done for a period of 1963-2003. Estimation of system losses, runoff from ungauged tributaries, and Gedebessa Swamp model parameters were considered in the flow process study. Simulation was conducted based on four scenarios. Consumptive and non-consumptive uses were considered in allocation modeling. The results of MODSIM model depict that there will be incremental release from Koka Dam from 2.8% to 5.7% in years 2018 and 2038, respectively. Due to increased diversions in Scenario III when compared to scenario I, losses in to Gedebessa Swamp will significantly decrease by an average of 27.6%. In the year 2038, owing to less capacity of upstream reservoirs due to sedimentation, water will be lost in the swamp complex causing slight decrease of inflow to Tendaho Dam. Additional storage at or upstream of Koka Dam will be mandatory in the future. Unaccounted water diversions upstream of Koka and water losses in Gedebessa Swamp should be considered in the

  3. Traffic Behavior Recognition Using the Pachinko Allocation Model

    PubMed Central

    Huynh-The, Thien; Banos, Oresti; Le, Ba-Vui; Bui, Dinh-Mao; Yoon, Yongik; Lee, Sungyoung

    2015-01-01

    CCTV-based behavior recognition systems have gained considerable attention in recent years in the transportation surveillance domain for identifying unusual patterns, such as traffic jams, accidents, dangerous driving and other abnormal behaviors. In this paper, a novel approach for traffic behavior modeling is presented for video-based road surveillance. The proposed system combines the pachinko allocation model (PAM) and support vector machine (SVM) for a hierarchical representation and identification of traffic behavior. A background subtraction technique using Gaussian mixture models (GMMs) and an object tracking mechanism based on Kalman filters are utilized to firstly construct the object trajectories. Then, the sparse features comprising the locations and directions of the moving objects are modeled by PAM into traffic topics, namely activities and behaviors. As a key innovation, PAM captures not only the correlation among the activities, but also among the behaviors based on the arbitrary directed acyclic graph (DAG). The SVM classifier is then utilized on top to train and recognize the traffic activity and behavior. The proposed model shows more flexibility and greater expressive power than the commonly-used latent Dirichlet allocation (LDA) approach, leading to a higher recognition accuracy in the behavior classification. PMID:26151213

  4. Traffic Behavior Recognition Using the Pachinko Allocation Model.

    PubMed

    Huynh-The, Thien; Banos, Oresti; Le, Ba-Vui; Bui, Dinh-Mao; Yoon, Yongik; Lee, Sungyoung

    2015-01-01

    CCTV-based behavior recognition systems have gained considerable attention in recent years in the transportation surveillance domain for identifying unusual patterns, such as traffic jams, accidents, dangerous driving and other abnormal behaviors. In this paper, a novel approach for traffic behavior modeling is presented for video-based road surveillance. The proposed system combines the pachinko allocation model (PAM) and support vector machine (SVM) for a hierarchical representation and identification of traffic behavior. A background subtraction technique using Gaussian mixture models (GMMs) and an object tracking mechanism based on Kalman filters are utilized to firstly construct the object trajectories. Then, the sparse features comprising the locations and directions of the moving objects are modeled by PAMinto traffic topics, namely activities and behaviors. As a key innovation, PAM captures not only the correlation among the activities, but also among the behaviors based on the arbitrary directed acyclic graph (DAG). The SVM classifier is then utilized on top to train and recognize the traffic activity and behavior. The proposed model shows more flexibility and greater expressive power than the commonly-used latent Dirichlet allocation (LDA) approach, leading to a higher recognition accuracy in the behavior classification. PMID:26151213

  5. Heterotypic Sam-Sam association between Odin-Sam1 and Arap3-Sam: binding affinity and structural insights

    PubMed Central

    Mercurio, Flavia A.; Marasco, Daniela; Pirone, Luciano; Scognamiglio, Pasqualina L.; Pedone, Emilia M.; Pellecchia, Maurizio

    2013-01-01

    Arap3 is a phosphatidylinositol 3 kinase effector protein that plays a role as GTP-ase activator (GAP) for Arf6 and RhoA. Arap3 contains a sterile alpha motif (Sam) domain that presents high sequence homology with the Sam domain of the EphA2-receptor (EphA2-Sam); both Arap3-Sam and EphA2-Sam are able to associate with the Sam domain of the lipid phosphatase Ship2 (Ship2-Sam). Recently, we have reported on a novel interaction between the first Sam domain of Odin (Odin-Sam1), a protein belonging to the ANKS (ANKyrin repeat and Sam domain containing) family, and EphA2-Sam. In the current work we apply Nuclear Magnetic Resonance (NMR) spectroscopy, Surface Plasmon Resonance (SPR) and Isothermal Titration Calorimetry (ITC) to characterize the association between Arap3-Sam and Odin-Sam1. We show that these two Sam domains interact with low micromolar affinity. Moreover, by means of molecular docking techniques, supported by NMR data, we demonstrate that Odin-Sam1 and Arap3-Sam may bind with a topology that is common to several Sam-Sam complexes. The unveiled structural details form the basis for the design of potential peptide-antagonists, that could be used as chemical tools to investigate functional aspects related to heterotypic Arap3-Sam associations. PMID:23239578

  6. Results and Comparison from the SAM Linear Fresnel Technology Performance Model: Preprint

    SciTech Connect

    Wagner, M. J.

    2012-04-01

    This paper presents the new Linear Fresnel technology performance model in NREL's System Advisor Model. The model predicts the financial and technical performance of direct-steam-generation Linear Fresnel power plants, and can be used to analyze a range of system configurations. This paper presents a brief discussion of the model formulation and motivation, and provides extensive discussion of the model performance and financial results. The Linear Fresnel technology is also compared to other concentrating solar power technologies in both qualitative and quantitative measures. The Linear Fresnel model - developed in conjunction with the Electric Power Research Institute - provides users with the ability to model a variety of solar field layouts, fossil backup configurations, thermal receiver designs, and steam generation conditions. This flexibility aims to encompass current market solutions for the DSG Linear Fresnel technology, which is seeing increasing exposure in fossil plant augmentation and stand-alone power generation applications.

  7. Synthia Tonn, SAM Engineer

    NASA Video Gallery

    The Sample Analysis at Mars (SAM) is a suite of instruments developed for use on the Mars Science Laboratory, designed to help find out whether or not Mars ever supported life. This video profiles ...

  8. The Marshall Engineering Thermosphere model atmosphere Statistical Analysis Mode (MET-SAM)

    NASA Technical Reports Server (NTRS)

    Smith, Robert E.; Catlett, Karen; Anderson, B. Jeffrey

    1991-01-01

    The minimum, mean, and maximum exospheric temperature on the globe were calculated for every three hour period from 1947 through 1989 using the algorithms in the Marshall Engineering Thermosphere (MET) model and the appropriate solar activity input parameters. Cumulative percent frequency (CPF) distributions were then calculated for each of these temperatures at five levels of solar activity as defined by the 13-month smoothed values of the 10.7-cm solar radio noise flux. Next, the 50, 95, 97.7, and 100 percentile temperature values in each of these five levels of solar activity were curve fit as a function of the 13-month smoothed 10.7-cm flux. The resulting algorithms are used to compute the exospheric temperature in the MET model instead of the technique developed by Jacchia in his 1970 model. These temperatures are then used to enter tables to determine the total mass density and/or the atomic oxygen number density for application to engineering problems. Users can specify the risk level they are willing to accept in the results of analyses that require neutral atmosphere parameters inputs. The model eliminates the guess work in how to combine the solar activity input parameters to insure that the results provide answers at the proper risk levels.

  9. Modeling and Simulation of Water Allocation System Based on Simulated Annealing Hybrid Genetic Algorithm

    NASA Astrophysics Data System (ADS)

    Zhu, Jiulong; Wang, Shijun

    Presently water resource in most watersheds in China is distributed in terms of administrative instructions. This kind of allocation method has many disadvantages and hampers the instructional effect of market mechanism on water allocation. The paper studies South-to-North Water Transfer Project and discusses water allocation of the node lakes along the Project. Firstly, it advanced four assumptions. Secondly, it analyzed constraint conditions of water allocation in terms of present state of water allocation in China. Thirdly, it established a goal model of water allocation and set up a systematic model from the angle of comprehensive profits of water utilization and profits of the node lakes. Fourthly, it discussed calculation method of the model by means of Simulated Annealing Hybrid Genetic Algorithm (SHGA). Finally, it validated the rationality and validity of the model by a simulation testing.

  10. Fast and slow responses of Southern Ocean sea surface temperature to SAM in coupled climate models

    NASA Astrophysics Data System (ADS)

    Krishnamurti, T. N.; Kumar, Vinay; Simon, Anu; Thomas, Aype; Bhardwaj, Amit; Das, Sweta; Senroy, Soma; Roy Bhowmik, S. K.

    2016-06-01

    A major rain storm in Uttarakhand (India) caused heavy rains and major loss of life from floods and land slide during 16-18 June, 2013. The observed daily maximum rainfall rates (3-hourly) during the 16th and 17th June were 220 and 340 mm respectively. This event is addressed via sensitivity studies using a cloud resolving non-hydrostatic model with detailed microphysics. The streaming of moist air from the east-south-east and warmer air from the south-west contributed to the sustained large population and amplitude of buoyancy and the associated CAPE contributed to the longer period of heavy rains. This study addresses the concept of Buoyancy as a means for large vertical accelerations, stronger vertical motions, extreme rain rates and the mechanisms that relate to the time rates of change. A post-processing algorithm provides an analysis of time rate of change for the buoyancy. Moist air streams and warm/moist air intrusions into heavily raining clouds are part of this buoyancy enhancement framework. Improvements in modeling of the extreme rain event came from adaptive observational strategy that showed lack of moisture data sets in these vital regions. We show that a moist boundary layer near the Bay of Bengal leads to moist rivers of moisture where the horizontal convergence confines a large population of buoyancy elements with large magnitudes of buoyancy that streams towards the region of extreme orographic rains. The areas covered in this study include: (i) Use of high resolution cloud modeling (1-km), (ii) Now casting of rains using physical initialization with a Newtonian relaxation, (iii) Use of an adaptive observational strategy, (iii) Sensitivity of the evolution of fields and population of buoyancy elements to boundary layer moisture, (iv) Role of orography and details of buoyancy budget.

  11. Modeling healthcare data using multiple-channel latent Dirichlet allocation.

    PubMed

    Lu, Hsin-Min; Wei, Chih-Ping; Hsiao, Fei-Yuan

    2016-04-01

    Information and communications technologies have enabled healthcare institutions to accumulate large amounts of healthcare data that include diagnoses, medications, and additional contextual information such as patient demographics. To gain a better understanding of big healthcare data and to develop better data-driven clinical decision support systems, we propose a novel multiple-channel latent Dirichlet allocation (MCLDA) approach for modeling diagnoses, medications, and contextual information in healthcare data. The proposed MCLDA model assumes that a latent health status group structure is responsible for the observed co-occurrences among diagnoses, medications, and contextual information. Using a real-world research testbed that includes one million healthcare insurance claim records, we investigate the utility of MCLDA. Our empirical evaluation results suggest that MCLDA is capable of capturing the comorbidity structures and linking them with the distribution of medications. Moreover, MCLDA is able to identify the pairing between diagnoses and medications in a record based on the assigned latent groups. MCLDA can also be employed to predict missing medications or diagnoses given partial records. Our evaluation results also show that, in most cases, MCLDA outperforms alternative methods such as logistic regressions and the k-nearest-neighbor (KNN) model for two prediction tasks, i.e., medication and diagnosis prediction. Thus, MCLDA represents a promising approach to modeling healthcare data for clinical decision support. PMID:26898516

  12. EPA-SUPPORTED (ENVIRONMENTAL PROTECTION AGENCY-SUPPORTED) WASTELOAD ALLOCATION MODELS

    EPA Science Inventory

    Modeling is increasingly becoming part of the Wasteload Allocation Process. The U.S. EPA provides guidance, technical training and computer software in support of this program. This paper reviews the support available to modelers through the Wasteload Allocation Section of EPA's ...

  13. A Model of Resource Allocation in Public School Districts: A Theoretical and Empirical Analysis.

    ERIC Educational Resources Information Center

    Chambers, Jay G.

    This paper formulates a comprehensive model of resource allocation in a local public school district. The theoretical framework specified could be applied equally well to any number of local public social service agencies. Section 1 develops the theoretical model describing the process of resource allocation. This involves the determination of the…

  14. The senescence-accelerated mouse (SAM): a higher oxidative stress and age-dependent degenerative diseases model.

    PubMed

    Chiba, Yoichi; Shimada, Atsuyoshi; Kumagai, Naoko; Yoshikawa, Keisuke; Ishii, Sanae; Furukawa, Ayako; Takei, Shiro; Sakura, Masaaki; Kawamura, Noriko; Hosokawa, Masanori

    2009-04-01

    The SAM strain of mice is actually a group of related inbred strains consisting of a series of SAMP (accelerated senescence-prone) and SAMR (accelerated senescence-resistant) strains. Compared with the SAMR strains, the SAMP strains show a more accelerated senescence process, a shorter lifespan, and an earlier onset and more rapid progress of age-associated pathological phenotypes similar to human geriatric disorders. The higher oxidative stress status observed in SAMP mice is partly caused by mitochondrial dysfunction, and may be a cause of this senescence acceleration and age-dependent alterations in cell structure and function. Based on our recent observations, we discuss a possible mechanism for mitochondrial dysfunction resulting in the excessive production of reactive oxygen species, and a role for the hyperoxidative stress status in neurodegeneration in SAMP mice. These SAM strains can serve as a useful tool to understand the cellular mechanisms of age-dependent degeneration, and to develop clinical interventions. PMID:18688709

  15. Reverse Resource Allocation: A Multi-Model, Multi-Goal Approach.

    ERIC Educational Resources Information Center

    Joiner, Carl

    1981-01-01

    Describes the management planning and control system (MPCS) model for handling program cutbacks (reverse resource allocation), which incorporates elements of zero base budgeting, goal programing, and the effectiveness evaluation-resource allocation process. Applies MPCS to cutbacks at the College of Business Administration at the University of…

  16. Integrated optimal allocation model for complex adaptive system of water resources management (I): Methodologies

    NASA Astrophysics Data System (ADS)

    Zhou, Yanlai; Guo, Shenglian; Xu, Chong-Yu; Liu, Dedi; Chen, Lu; Ye, Yushi

    2015-12-01

    Due to the adaption, dynamic and multi-objective characteristics of complex water resources system, it is a considerable challenge to manage water resources in an efficient, equitable and sustainable way. An integrated optimal allocation model is proposed for complex adaptive system of water resources management. The model consists of three modules: (1) an agent-based module for revealing evolution mechanism of complex adaptive system using agent-based, system dynamic and non-dominated sorting genetic algorithm II methods, (2) an optimal module for deriving decision set of water resources allocation using multi-objective genetic algorithm, and (3) a multi-objective evaluation module for evaluating the efficiency of the optimal module and selecting the optimal water resources allocation scheme using project pursuit method. This study has provided a theoretical framework for adaptive allocation, dynamic allocation and multi-objective optimization for a complex adaptive system of water resources management.

  17. Model-based metrics of human-automation function allocation in complex work environments

    NASA Astrophysics Data System (ADS)

    Kim, So Young

    Function allocation is the design decision which assigns work functions to all agents in a team, both human and automated. Efforts to guide function allocation systematically has been studied in many fields such as engineering, human factors, team and organization design, management science, and cognitive systems engineering. Each field focuses on certain aspects of function allocation, but not all; thus, an independent discussion of each does not address all necessary issues with function allocation. Four distinctive perspectives emerged from a review of these fields: technology-centered, human-centered, team-oriented, and work-oriented. Each perspective focuses on different aspects of function allocation: capabilities and characteristics of agents (automation or human), team structure and processes, and work structure and the work environment. Together, these perspectives identify the following eight issues with function allocation: 1) Workload, 2) Incoherency in function allocations, 3) Mismatches between responsibility and authority, 4) Interruptive automation, 5) Automation boundary conditions, 6) Function allocation preventing human adaptation to context, 7) Function allocation destabilizing the humans' work environment, and 8) Mission Performance. Addressing these issues systematically requires formal models and simulations that include all necessary aspects of human-automation function allocation: the work environment, the dynamics inherent to the work, agents, and relationships among them. Also, addressing these issues requires not only a (static) model, but also a (dynamic) simulation that captures temporal aspects of work such as the timing of actions and their impact on the agent's work. Therefore, with properly modeled work as described by the work environment, the dynamics inherent to the work, agents, and relationships among them, a modeling framework developed by this thesis, which includes static work models and dynamic simulation, can capture the

  18. Inverse modeling in magnetic source imaging: Comparison of MUSIC, SAM(g2), and sLORETA to interictal intracranial EEG.

    PubMed

    de Gooijer-van de Groep, Karin L; Leijten, Frans S S; Ferrier, Cyrille H; Huiskamp, Geertjan J M

    2013-09-01

    Magnetoencephalography (MEG) is used in the presurgical work-up of patients with focal epilepsy. In particular, localization of MEG interictal spikes may guide or replace invasive electroencephalography monitoring that is required in difficult cases. From literature, it is not clear which MEG source localization method performs best in this clinical setting. Therefore, we applied three source localization methods to the same data from a large patient group for which a gold standard, interictal spikes as identified in electrocorticography (ECoG), was available. The methods used were multiple signal classification (MUSIC), Synthetic Aperture Magnetometry kurtosis [SAM(g2)], and standardized low-resolution electromagnetic tomography. MEG and ECoG data from 38 patients with refractory focal epilepsy were obtained. Results of the three source localization methods applied to the interictal MEG data were assigned to predefined anatomical regions. Interictal spikes as identified in ECoG were also assigned to these regions. Identified regions by each MEG method were compared to ECoG. Sensitivity and positive predictive value (PPV) of each MEG method were calculated. All three MEG methods showed a similar overall correlate with ECoG spikes, but the methods differ in which regions they detect. The choice of the inverse model thus has an unexpected influence on the results of magnetic source imaging. Combining inverse methods and seeking consensus can be used to improve specificity at the cost of some sensitivity. Combining MUSIC with SAM(g2) gives the best results (sensitivity = 38% and PPV = 82%). PMID:22431346

  19. Technical-guidance manual for performing waste-load allocations. Book 3: Estuaries. Part 1: Estuaries and waste-load allocation models

    SciTech Connect

    Ambrose, R.B.; Martin, J.L.

    1990-05-01

    The document provides technical information and policy guidance for allocating wastewater discharges among multiple dischargers in estuarine waters. It summarizes the important water quality problems, estuarine characteristics, and the simulation models available for addressing these problems.

  20. Common themes and differences in SAM recognition among SAM riboswitches

    PubMed Central

    Price, Ian R.; Grigg, Jason C.; Ke, Ailong

    2014-01-01

    The recent discovery of short cis-acting RNA elements termed riboswitches has caused a paradigm shift in our understanding of genetic regulatory mechanisms. The three distinct superfamilies of S-adenosyl-L-methionine (SAM) riboswitches are the most commonly found riboswitch classes in nature. These RNAs represent three independent evolutionary solutions to achieve specific SAM recognition. This review summarizes research on 1) modes of gene regulatory mechanisms, 2) common themes and differences in ligand recognition, and 3) ligand-induced conformational dynamics among SAM riboswitch families. The body of work on the SAM riboswitch families constitutes a useful primer to the topic of gene regulatory RNAs as a whole. PMID:24863160

  1. Neural Network Based Modeling and Analysis of LP Control Surface Allocation

    NASA Technical Reports Server (NTRS)

    Langari, Reza; Krishnakumar, Kalmanje; Gundy-Burlet, Karen

    2003-01-01

    This paper presents an approach to interpretive modeling of LP based control allocation in intelligent flight control. The emphasis is placed on a nonlinear interpretation of the LP allocation process as a static map to support analytical study of the resulting closed loop system, albeit in approximate form. The approach makes use of a bi-layer neural network to capture the essential functioning of the LP allocation process. It is further shown via Lyapunov based analysis that under certain relatively mild conditions the resulting closed loop system is stable. Some preliminary conclusions from a study at Ames are stated and directions for further research are given at the conclusion of the paper.

  2. A simple model to optimize resource allocations when expanding the faculty research base: a case study.

    PubMed

    Joiner, Keith A

    2009-01-01

    Construction of new biomedical research facilities has outpaced the funding sources for faculty to occupy those facilities. This puts a premium on the efficient allocation of central resources for faculty recruitment. The author developed a mathematical model to determine the optimal structure (dollars, space) for allocating resource packages when recruiting new faculty, based on expected financial returns from those faculty. Surprisingly, the optimal strategy was to allocate homogeneous recruitment packages, independent of the recruited faculty member's rank or the individual's expected revenue generation. Optimization results were used to allocate recruitment packages to new department head and center directors in the University of Arizona College of Medicine during the last four years (2005-2008). At any institution that uses this model, appropriate distribution of facilities and administrative revenues at the institution is needed to equitably balance the costs and benefits associated with faculty expansion. PMID:19116472

  3. HIV EPIDEMIC CONTROL — A MODEL FOR OPTIMAL ALLOCATION OF PREVENTION AND TREATMENT RESOURCES

    PubMed Central

    Alistar, Sabina S.; Long, Elisa F.; Brandeau, Margaret L.; Beck, Eduard J.

    2013-01-01

    With 33 million people living with human immunodeficiency virus (HIV) worldwide and 2.7 million new infections occurring annually, additional HIV prevention and treatment efforts are urgently needed. However, available resources for HIV control are limited and must be used efficiently to minimize the future spread of the epidemic. We develop a model to determine the appropriate resource allocation between expanded HIV prevention and treatment services. We create an epidemic model that incorporates multiple key populations with different transmission modes, as well as production functions that relate investment in prevention and treatment programs to changes in transmission and treatment rates. The goal is to allocate resources to minimize R0, the reproductive rate of infection. We first develop a single-population model and determine the optimal resource allocation between HIV prevention and treatment. We extend the analysis to multiple independent populations, with resource allocation among interventions and populations. We then include the effects of HIV transmission between key populations. We apply our model to examine HIV epidemic control in two different settings, Uganda and Russia. As part of these applications, we develop a novel approach for estimating empirical HIV program production functions. Our study provides insights into the important question of resource allocation for a country's optimal response to its HIV epidemic and provides a practical approach for decision makers. Better decisions about allocating limited HIV resources can improve response to the epidemic and increase access to HIV prevention and treatment services for millions of people worldwide. PMID:23793895

  4. Resource Allocation in Healthcare: Implications of Models of Medicine as a Profession

    PubMed Central

    Kluge, Eike-Henner W.

    2007-01-01

    For decades, the problem of how to allocate healthcare resources in a just and equitable fashion has been the subject of concerted discussion and analysis, yet the issue has stubbornly resisted resolution. This article suggests that a major reason for this is that the discussion has focused exclusively on the nature and status of the material resources, and that the nature and role of the medical profession have been entirely ignored. Because physicians are gatekeepers to healthcare resources, their role in allocation is central from a process perspective. This article identifies 3 distinct interpretations of the nature of medicine, shows how each mandates a different method of allocation, and argues that unless an appropriate model of medicine is developed that acknowledges the valid points contained in each of the 3 approaches, the allocation problem will remain unsolvable. PMID:17435657

  5. Neural network models for a resource allocation problem.

    PubMed

    Walczak, S

    1998-01-01

    University admissions and business personnel offices use a limited number of resources to process an ever-increasing quantity of student and employment applications. Application systems are further constrained to identify and acquire, in a limited time period, those candidates who are most likely to accept an offer of enrolment or employment. Neural networks are a new methodology to this particular domain. Various neural network architectures and learning algorithms are analyzed comparatively to determine the applicability of supervised learning neural networks to the domain problem of personnel resource allocation and to identify optimal learning strategies in this domain. This paper focuses on multilayer perceptron backpropagation, radial basis function, counterpropagation, general regression, fuzzy ARTMAP, and linear vector quantization neural networks. Each neural network predicts the probability of enrolment and nonenrolment for individual student applicants. Backpropagation networks produced the best overall performance. Network performance results are measured by the reduction in counsellors student case load and corresponding increases in student enrolment. The backpropagation neural networks achieve a 56% reduction in counsellor case load. PMID:18255946

  6. A Mathematical Programming Model for the Efficient Allocation of Vocational Technical Education Funds.

    ERIC Educational Resources Information Center

    McNamara, James F.

    This mathematical programing model was developed to provide the State Board of Education with complete information for evaluating decisions about the efficient allocation of vocational education funds to local school districts. The model, based on a supply-demand criterion, was tested on a set of occupational training programs within a given Labor…

  7. The Health Resources Allocation Model (HRAM) for the 21st century.

    PubMed

    Maire, Nicolas; Hegnauer, Michael; Nguyen, Dana; Godelmann, Lucas; Hoffmann, Axel; de Savigny, Don; Tanner, Marcel

    2012-05-01

    The Health Resources Allocation Model (HRAM) is an eLearning tool for health cadres and scientists introducing basic concepts of sub-national, rational district-based health planning and systems thinking under resources constraint. HRAM allows the evaluation of resource allocation strategies in relation to key outcome measures such as coverage, equity of services achieved and number of deaths and disability-adjusted life years (DALYs) prevented. In addition, the model takes into account geographical and demographic characteristics and populations' health seeking behaviour. It can be adapted to different socio-ecological and health system settings. PMID:22639131

  8. Structural insights into SAM domain-mediated tankyrase oligomerization.

    PubMed

    DaRosa, Paul A; Ovchinnikov, Sergey; Xu, Wenqing; Klevit, Rachel E

    2016-09-01

    Tankyrase 1 (TNKS1; a.k.a. ARTD5) and tankyrase 2 (TNKS2; a.k.a ARTD6) are highly homologous poly(ADP-ribose) polymerases (PARPs) that function in a wide variety of cellular processes including Wnt signaling, Src signaling, Akt signaling, Glut4 vesicle translocation, telomere length regulation, and centriole and spindle pole maturation. Tankyrase proteins include a sterile alpha motif (SAM) domain that undergoes oligomerization in vitro and in vivo. However, the SAM domains of TNKS1 and TNKS2 have not been structurally characterized and the mode of oligomerization is not yet defined. Here we model the SAM domain-mediated oligomerization of tankyrase. The structural model, supported by mutagenesis and NMR analysis, demonstrates a helical, homotypic head-to-tail polymer that facilitates TNKS self-association. Furthermore, we show that TNKS1 and TNKS2 can form (TNKS1 SAM-TNKS2 SAM) hetero-oligomeric structures mediated by their SAM domains. Though wild-type tankyrase proteins have very low solubility, model-based mutations of the SAM oligomerization interface residues allowed us to obtain soluble TNKS proteins. These structural insights will be invaluable for the functional and biophysical characterization of TNKS1/2, including the role of TNKS oligomerization in protein poly(ADP-ribosyl)ation (PARylation) and PARylation-dependent ubiquitylation. PMID:27328430

  9. Visual Attention Allocation Between Robotic Arm and Environmental Process Control: Validating the STOM Task Switching Model

    NASA Technical Reports Server (NTRS)

    Wickens, Christopher; Vieanne, Alex; Clegg, Benjamin; Sebok, Angelia; Janes, Jessica

    2015-01-01

    Fifty six participants time shared a spacecraft environmental control system task with a realistic space robotic arm control task in either a manual or highly automated version. The former could suffer minor failures, whose diagnosis and repair were supported by a decision aid. At the end of the experiment this decision aid unexpectedly failed. We measured visual attention allocation and switching between the two tasks, in each of the eight conditions formed by manual-automated arm X expected-unexpected failure X monitoring- failure management. We also used our multi-attribute task switching model, based on task attributes of priority interest, difficulty and salience that were self-rated by participants, to predict allocation. An un-weighted model based on attributes of difficulty, interest and salience accounted for 96 percent of the task allocation variance across the 8 different conditions. Task difficulty served as an attractor, with more difficult tasks increasing the tendency to stay on task.

  10. Ethical models in bioethics: theory and application in organ allocation policies.

    PubMed

    Petrini, C

    2010-12-01

    Policies for allocating organs to people awaiting a transplant constitute a major ethical challenge. First and foremost, they demand balance between the principles of beneficence and justice, but many other ethically relevant principles are also involved: autonomy, responsibility, equity, efficiency, utility, therapeutic outcome, medical urgency, and so forth. Various organ allocation models can be developed based on the hierarchical importance assigned to a given principle over the others, but none of the principles should be completely disregarded. An ethically acceptable organ allocation policy must therefore be in conformity, to a certain extent, with the requirements of all the principles. Many models for organ allocation can be derived. The utilitarian model aims to maximize benefits, which can be of various types on a social or individual level, such as the number of lives saved, prognosis, and so forth. The prioritarian model favours the neediest or those who suffer most. The egalitarian model privileges equity and justice, suggesting that all people should have an equal opportunity (casual allocation) or priority should be given to those who have been waiting longer. The personalist model focuses on each individual patient, attempting to mesh together all the various aspects affecting the person: therapeutic needs (urgency), fairness, clinical outcomes, respect for persons. In the individualistic model the main element is free choice and the system of opting-in is privileged. Contrary to the individualistic model, the communitarian model identities in the community the fundamental elements for the legitimacy of choices: therefore, the system of opting-out is privileged. This article does not aim at suggesting practical solutions. Rather, it furnishes to decision makers an overview on the possible ethical approach to this matter. PMID:21196904

  11. The Impacts of Different Types of Workload Allocation Models on Academic Satisfaction and Working Life

    ERIC Educational Resources Information Center

    Vardi, Iris

    2009-01-01

    Increasing demands on academic work have resulted in many academics working long hours and expressing dissatisfaction with their working life. These concerns have led to a number of faculties and universities adopting workload allocation models to improve satisfaction and better manage workloads. This paper reports on a study which examined the…

  12. Faces of Marshall: Sam Ortega

    NASA Video Gallery

    Several Marshall employees were interviewed as part of Marshall's 50th Anniversary activities. Engineer Sam Ortega tells his story of how he came to work as an engineer at Marshall and how sewing a...

  13. SAM II Data and Information

    Atmospheric Science Data Center

    2016-07-06

    ... Data obtained from the Stratospheric Aerosol Measurement (SAM) II instrument, which flew on board the Nimbus-7 ... Spatial Resolution:  The altitude profiles of aerosol extinction have a 1 km vertical resolution. Temporal ...

  14. A modeling framework for inferring tree growth and allocation from physiological, morphological and allometric traits.

    PubMed

    Ogle, Kiona; Pacala, Stephen W

    2009-04-01

    Predictions of forest succession, diversity and function require an understanding of how species differ in their growth, allocation patterns and susceptibility to mortality. These processes in turn are affected by allometric constraints and the physiological state of the tree, both of which are coupled to the tree's labile carbon status. Ultimately, insight into the hidden labile pools and the processes affecting the allocation of labile carbon to storage, maintenance and growth will improve our ability to predict tree growth, mortality and forest dynamics. We developed the 'Allometrically Constrained Growth and Carbon Allocation' (ACGCA) model that explicitly couples tree growth, mortality, allometries and labile carbon. This coupling results in (1) a semi-mechanistic basis for predicting tree death, (2) an allocation scheme that simultaneously satisfies allometric relationships and physiology-based carbon dynamics and (3) a range of physiological states that are consistent with tree behavior (e.g., healthy, static, shrinking, recovering, recovered and dead). We present the ACGCA model and illustrate aspects of its behavior by conducting simulations under different forest gap dynamics scenarios and with parameter values obtained for two ecologically dissimilar species: loblolly pine (Pinus taeda L.) and red maple (Acer rubrum L.). The model reproduces growth and mortality patterns of these species that are consistent with their shade-tolerance and succession status. The ACGCA framework provides an alternative, and potentially improved, approach for predicting tree growth, mortality and forest dynamics. PMID:19203984

  15. Modeling forest C and N allocation responses to free-air CO2 enrichment

    NASA Astrophysics Data System (ADS)

    Luus, Kristina; De Kauwe, Martin; Walker, Anthony; Werner, Christian; Iversen, Colleen; McCarthy, Heather; Medlyn, Belinda; Norby, Richard; Oren, Ram; Zak, Donald; Zaehle, Sönke

    2015-04-01

    Vegetation allocation patterns and soil-vegetation partitioning of C and N are predicted to change in response to rising atmospheric concentrations of CO2. These allocation responses to rising CO2 have been examined at the ecosystem level through through free-air CO2 enrichment (FACE) experiments, and their global implications for the timing of progressive N limitation (PNL) and C sequestration have been predicted for ~100 years using a variety of ecosystem models. However, recent FACE model-data syntheses studies [1,2,3] have indicated that ecosystem models do not capture the 5-10 year site-level ecosystem allocation responses to elevated CO2. This may be due in part to the missing representation of the rhizosphere interactions between plants and soil biota in models. Ecosystem allocation of C and N is altered by interactions between soil and vegetation through the priming effect: as plant N availability diminishes, plants respond physiologically by altering their tissue allocation strategies so as to increase rates of root growth and rhizodeposition. In response, either soil organic material begins to accumulate, which hastens the onset of PNL, or soil microbes start to decompose C more rapidly, resulting in increased N availability for plant uptake, which delays PNL. In this study, a straightforward approach for representing rhizosphere interactions in ecosystem models was developed through which C and N allocation to roots and rhizodeposition responds dynamically to elevated CO2 conditions, modifying soil decomposition rates without pre-specification of the direction in which soil C and N accumulation should shift in response to elevated CO2. This approach was implemented in a variety of ecosystem models ranging from stand (G'DAY), to land surface (CLM 4.5, O-CN), to dynamic global vegetation (LPJ-GUESS) models. Comparisons against data from three forest FACE sites (Duke, Oak Ridge & Rhinelander) indicated that representing rhizosphere interactions allowed

  16. Stability of mixed PEO-thiol SAMs for biosensing applications.

    PubMed

    Jans, Karolien; Bonroy, Kristien; De Palma, Randy; Reekmans, Gunter; Jans, Hilde; Laureyn, Wim; Smet, Mario; Borghs, Gustaaf; Maes, Guido

    2008-04-15

    The secret of a successful affinity biosensor partially hides in the chemical interface layer between the transducer system and the biological receptor molecules. Over the past decade, several methodologies for the construction of such interface layers have been developed on the basis of the deposition of self-assembled monolayers (SAMs) of alkanethiols on gold. Moreover, mixed SAMs of polyethylene oxide (PEO) containing thiols have been applied for the immobilization of biological receptors. Despite the intense research in the field of thiol SAMs, relatively little is known about their biosensing properties in correlation with their long-term stability. Especially the impact of the storage conditions on their biosensing characteristics has not been reported before to our knowledge. To address these issues, we prepared mixed PEO SAMs and tested their stability and biosensing performance in several storage conditions, i.e., air, N2, ethanol, phosphate buffer, and H2O. The quality of the SAMs was monitored as a function of time using various characterization techniques such as cyclic voltammetry, contact angle, grazing angle Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. In addition, the impact of the different storage conditions on the biosensor properties was investigated using surface plasmon resonance. Via the latter technique, the receptor immobilization, the analyte recognition, and the nonspecific binding were extensively studied using the prostate specific antigen as a model system. Our experiments showed that very small structural differences in the SAM can have a great impact in their final biosensing properties. In addition it was shown that the mixed SAMs stored in air or N2 are very stable and retain their biosensor properties for at least 30 days, while ethanol appeared to be the worst storage medium due to partial oxidation of the thiol headgroup. In conclusion, care must be taken to avoid SAM degradation during storage

  17. Technical documentation and user's guide for City-County Allocation Model (CCAM). Version 1. 0

    SciTech Connect

    Clark, L.T. Jr.; Scott, M.J.; Hammer, P.

    1986-05-01

    The City-County Allocation Model (CCAM) was developed as part of the Monitored Retrievable Storage (MRS) Program. The CCAM model was designed to allocate population changes forecasted by the MASTER model to specific local communities within commuting distance of the MRS facility. The CCAM model was designed to then forecast the potential changes in demand for key community services such as housing, police protection, and utilities for these communities. The CCAM model uses a flexible on-line data base on demand for community services that is based on a combination of local service levels and state and national service standards. The CCAM model can be used to quickly forecast the potential community service consequence of economic development for local communities anywhere in the country. The remainder of this document is organized as follows. The purpose of this manual is to assist the user in understanding and operating the City-County Allocation Model (CCAM). The annual explains the data sources for the model and code modifications as well as the operational procedures.

  18. Testing new approaches to carbonate system simulation at the reef scale: the ReefSam model first results, application to a question in reef morphology and future challenges.

    NASA Astrophysics Data System (ADS)

    Barrett, Samuel; Webster, Jody

    2016-04-01

    Numerical simulation of the stratigraphy and sedimentology of carbonate systems (carbonate forward stratigraphic modelling - CFSM) provides significant insight into the understanding of both the physical nature of these systems and the processes which control their development. It also provides the opportunity to quantitatively test conceptual models concerning stratigraphy, sedimentology or geomorphology, and allows us to extend our knowledge either spatially (e.g. between bore holes) or temporally (forwards or backwards in time). The later is especially important in determining the likely future development of carbonate systems, particularly regarding the effects of climate change. This application, by its nature, requires successful simulation of carbonate systems on short time scales and at high spatial resolutions. Previous modelling attempts have typically focused on the scales of kilometers and kilo-years or greater (the scale of entire carbonate platforms), rather than at the scale of centuries or decades, and tens to hundreds of meters (the scale of individual reefs). Previous work has identified limitations in common approaches to simulating important reef processes. We present a new CFSM, Reef Sedimentary Accretion Model (ReefSAM), which is designed to test new approaches to simulating reef-scale processes, with the aim of being able to better simulate the past and future development of coral reefs. Four major features have been tested: 1. A simulation of wave based hydrodynamic energy with multiple simultaneous directions and intensities including wave refraction, interaction, and lateral sheltering. 2. Sediment transport simulated as sediment being moved from cell to cell in an iterative fashion until complete deposition. 3. A coral growth model including consideration of local wave energy and composition of the basement substrate (as well as depth). 4. A highly quantitative model testing approach where dozens of output parameters describing the reef

  19. Allocation Variable-Based Probabilistic Algorithm to Deal with Label Switching Problem in Bayesian Mixture Models

    PubMed Central

    Pan, Jia-Chiun; Liu, Chih-Min; Hwu, Hai-Gwo; Huang, Guan-Hua

    2015-01-01

    The label switching problem occurs as a result of the nonidentifiability of posterior distribution over various permutations of component labels when using Bayesian approach to estimate parameters in mixture models. In the cases where the number of components is fixed and known, we propose a relabelling algorithm, an allocation variable-based (denoted by AVP) probabilistic relabelling approach, to deal with label switching problem. We establish a model for the posterior distribution of allocation variables with label switching phenomenon. The AVP algorithm stochastically relabel the posterior samples according to the posterior probabilities of the established model. Some existing deterministic and other probabilistic algorithms are compared with AVP algorithm in simulation studies, and the success of the proposed approach is demonstrated in simulation studies and a real dataset. PMID:26458185

  20. Omega-3 polyunsaturated fatty acids ameliorate the severity of ileitis in the senescence accelerated mice (SAM)P1/Yit mice model

    PubMed Central

    Matsunaga, H; Hokari, R; Kurihara, C; Okada, Y; Takebayashi, K; Okudaira, K; Watanabe, C; Komoto, S; Nakamura, M; Tsuzuki, Y; Kawaguchi, A; Nagao, S; Miura, S

    2009-01-01

    Clinical studies using omega-3 polyunsaturated fatty acids (ω3-PUFA) to Crohn's disease (CD) are conflicting. Beneficial effects of dietary ω3-PUFA intake in various experimental inflammatory bowel disease (IBD) models have been reported. However, animal models of large intestinal inflammation have been used in all previous studies, and the effect of ω3 fat in an animal model of small intestinal inflammation has not been reported. We hypothesized that the effects of ω3 fat are different between large and small intestine. The aim of this study was to determine whether the direct effect of ω3 fat is beneficial for small intestinal inflammation. Senescence accelerated mice (SAM)P1/Yit mice showed remarkable inflammation of the terminal ileum spontaneously. The numbers of F4/80-positive monocyte–macrophage cells as well as β7-integrin-positive lymphocytes in the intestinal mucosa were increased significantly compared with those in the control mice (AKR-J mice). The area of mucosal addressin cell adhesion molecule-1 (MAdCAM-1)-positive vessels was also increased. The degree of expression levels of monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-6 and interferon (IFN)-γ mRNA were increased significantly compared with those in the control mice. The feeding of two different kinds of ω3 fat (fish-oil-rich and perilla-oil-rich diets) for 16 weeks to SAMP1/Yit mice ameliorated inflammation of the terminal ileum significantly. In both the ω3-fat-rich diet groups, enhanced infiltration of F4/80-positive monocytes/macrophages in intestinal mucosa of SAMP1/Yit mice cells and the increased levels of MCP-1, IL-6 and IFN-γ mRNA expression were ameliorated significantly compared with those in the control diet group. The results suggest that ω3 fat is beneficial for small intestinal inflammation by inhibition of monocyte recruitment to inflamed intestinal mucosa. PMID:19793338

  1. Resources allocation in healthcare for cancer: a case study using generalised additive mixed models.

    PubMed

    Musio, Monica; Sauleau, Erik A; Augustin, Nicole H

    2012-11-01

    Our aim is to develop a method for helping resources re-allocation in healthcare linked to cancer, in order to replan the allocation of providers. Ageing of the population has a considerable impact on the use of health resources because aged people require more specialised medical care due notably to cancer. We propose a method useful to monitor changes of cancer incidence in space and time taking into account two age categories, according to healthcar general organisation. We use generalised additive mixed models with a Poisson response, according to the methodology presented in Wood, Generalised additive models: an introduction with R. Chapman and Hall/CRC, 2006. Besides one-dimensional smooth functions accounting for non-linear effects of covariates, the space-time interaction can be modelled using scale invariant smoothers. Incidence data collected by a general cancer registry between 1992 and 2007 in a specific area of France is studied. Our best model exhibits a strong increase of the incidence of cancer along time and an obvious spatial pattern for people more than 70 years with a higher incidence in the central band of the region. This is a strong argument for re-allocating resources for old people cancer care in this sub-region. PMID:23242683

  2. Integrated optimal allocation model for complex adaptive system of water resources management (II): Case study

    NASA Astrophysics Data System (ADS)

    Zhou, Yanlai; Guo, Shenglian; Xu, Chong-Yu; Liu, Dedi; Chen, Lu; Wang, Dong

    2015-12-01

    Climate change, rapid economic development and increase of the human population are considered as the major triggers of increasing challenges for water resources management. This proposed integrated optimal allocation model (IOAM) for complex adaptive system of water resources management is applied in Dongjiang River basin located in the Guangdong Province of China. The IOAM is calibrated and validated under baseline period 2010 year and future period 2011-2030 year, respectively. The simulation results indicate that the proposed model can make a trade-off between demand and supply for sustainable development of society, economy, ecology and environment and achieve adaptive management of water resources allocation. The optimal scheme derived by multi-objective evaluation is recommended for decision-makers in order to maximize the comprehensive benefits of water resources management.

  3. A model for dynamic allocation of human attention among multiple tasks

    NASA Technical Reports Server (NTRS)

    Sheridan, T. B.; Tulga, M. K.

    1978-01-01

    The problem of multi-task attention allocation with special reference to aircraft piloting is discussed with the experimental paradigm used to characterize this situation and the experimental results obtained in the first phase of the research. A qualitative description of an approach to mathematical modeling, and some results obtained with it are also presented to indicate what aspects of the model are most promising. Two appendices are given which (1) discuss the model in relation to graph theory and optimization and (2) specify the optimization algorithm of the model.

  4. SAM 2 data user's guide

    NASA Technical Reports Server (NTRS)

    Chu, W. P.; Osborn, M. T.; Mcmaster, L. R.

    1988-01-01

    This document is intended to serve as a guide to the use of the data products from the Stratospheric Aerosol Measurement (SAM) 2 experiment for scientific investigations of polar stratospheric aerosols. Included is a detailed description of the Beta and Aerosol Number Density Archive Tape (BANAT), which is the SAM 2 data product containing the aerosol extinction data available for these investigations. Also included are brief descriptions of the instrument operation, data collection, processing and validation, and some of the scientific analyses conducted to date.

  5. PID feedback controller used as a tactical asset allocation technique: The G.A.M. model

    NASA Astrophysics Data System (ADS)

    Gandolfi, G.; Sabatini, A.; Rossolini, M.

    2007-09-01

    The objective of this paper is to illustrate a tactical asset allocation technique utilizing the PID controller. The proportional-integral-derivative (PID) controller is widely applied in most industrial processes; it has been successfully used for over 50 years and it is used by more than 95% of the plants processes. It is a robust and easily understood algorithm that can provide excellent control performance in spite of the diverse dynamic characteristics of the process plant. In finance, the process plant, controlled by the PID controller, can be represented by financial market assets forming a portfolio. More specifically, in the present work, the plant is represented by a risk-adjusted return variable. Money and portfolio managers’ main target is to achieve a relevant risk-adjusted return in their managing activities. In literature and in the financial industry business, numerous kinds of return/risk ratios are commonly studied and used. The aim of this work is to perform a tactical asset allocation technique consisting in the optimization of risk adjusted return by means of asset allocation methodologies based on the PID model-free feedback control modeling procedure. The process plant does not need to be mathematically modeled: the PID control action lies in altering the portfolio asset weights, according to the PID algorithm and its parameters, Ziegler-and-Nichols-tuned, in order to approach the desired portfolio risk-adjusted return efficiently.

  6. Game Theoretic Modeling of Water Resources Allocation Under Hydro-Climatic Uncertainty

    NASA Astrophysics Data System (ADS)

    Brown, C.; Lall, U.; Siegfried, T.

    2005-12-01

    Typical hydrologic and economic modeling approaches rely on assumptions of climate stationarity and economic conditions of ideal markets and rational decision-makers. In this study, we incorporate hydroclimatic variability with a game theoretic approach to simulate and evaluate common water allocation paradigms. Game Theory may be particularly appropriate for modeling water allocation decisions. First, a game theoretic approach allows economic analysis in situations where price theory doesn't apply, which is typically the case in water resources where markets are thin, players are few, and rules of exchange are highly constrained by legal or cultural traditions. Previous studies confirm that game theory is applicable to water resources decision problems, yet applications and modeling based on these principles is only rarely observed in the literature. Second, there are numerous existing theoretical and empirical studies of specific games and human behavior that may be applied in the development of predictive water allocation models. With this framework, one can evaluate alternative orderings and rules regarding the fraction of available water that one is allowed to appropriate. Specific attributes of the players involved in water resources management complicate the determination of solutions to game theory models. While an analytical approach will be useful for providing general insights, the variety of preference structures of individual players in a realistic water scenario will likely require a simulation approach. We propose a simulation approach incorporating the rationality, self-interest and equilibrium concepts of game theory with an agent-based modeling framework that allows the distinct properties of each player to be expressed and allows the performance of the system to manifest the integrative effect of these factors. Underlying this framework, we apply a realistic representation of spatio-temporal hydrologic variability and incorporate the impact of

  7. SOLUTION STRUCTURE OF THE FIRST SAM DOMAIN OF ODIN AND BINDING STUDIES WITH THE EPHA2 RECEPTOR

    PubMed Central

    Mercurio, Flavia Anna; Marasco, Daniela; Pirone, Luciano; Pedone, Emilia Maria; Pellecchia, Maurizio; Leone, Marilisa

    2012-01-01

    The EphA2 receptor plays key roles in many physiological and pathological events including cancer. The process of receptor endocytosis and the consequent degradation have lately attracted attention as possible means of overcoming the negative outcomes of EphA2 in cancer cells and decreasing tumor malignancy. A recent study indicates that Sam (Sterile Alpha Motif) domains of Odin, a member of the ANKS (Ankyrin repeat and sterile alpha motif domain-containing) family of proteins, are important to regulate EphA2 endocytosis. Odin contains two tandem Sam domains (Odin-Sam1 and Sam2). Herein we report on the NMR solution structure of Odin-Sam1; through a variety of assays (employing NMR, SPR and ITC techniques), we clearly demonstrate that Odin-Sam1 binds to the Sam domain of EphA2 in the low micromolar range. NMR chemical shift perturbation experiments and molecular modeling studies point out that the two Sam domains interact with a head to tail topology characteristic of several Sam-Sam complexes. This binding mode is similar to that we have previously proposed for the association between the Sam domains of the lipid phosphatase Ship2 and EphA2. This work further validates structural elements relevant for the heterotypic Sam-Sam interactions of EphA2 and provides novel insights for the design of potential therapeutic compounds that can modulate receptor endocytosis. PMID:22332920

  8. SAM II Data and Information (ASCII)

    Atmospheric Science Data Center

    2016-09-01

    SAM II (ASCII) Data and Information Data obtained from the Stratospheric Aerosol Measurement (SAM) II instrument, ... Parameters:  Aerosols Order Data:  ASDC Order Tool:  Order Data Guide Documents:  ...

  9. SAM Overview: The Habitability of Mars

    NASA Video Gallery

    Featuring an interview with Paul Mahaffy, SAM's Principal Investigator, this video gives a general overview of SAM's mission aboard the Mars Science Laboratory, otherwise known as the Curiosity rover.

  10. Basin Economic Allocation Model (BEAM): An economic model of water use developed for the Aral Sea Basin

    NASA Astrophysics Data System (ADS)

    Riegels, Niels; Kromann, Mikkel; Karup Pedersen, Jesper; Lindgaard-Jørgensen, Palle; Sokolov, Vadim; Sorokin, Anatoly

    2013-04-01

    The water resources of the Aral Sea basin are under increasing pressure, particularly from the conflict over whether hydropower or irrigation water use should take priority. The purpose of the BEAM model is to explore the impact of changes to water allocation and investments in water management infrastructure on the overall welfare of the Aral Sea basin. The BEAM model estimates welfare changes associated with changes to how water is allocated between the five countries in the basin (Kazakhstan, Kyrgyz Republic, Tajikistan, Turkmenistan and Uzbekistan; water use in Afghanistan is assumed to be fixed). Water is allocated according to economic optimization criteria; in other words, the BEAM model allocates water across time and space so that the economic welfare associated with water use is maximized. The model is programmed in GAMS. The model addresses the Aral Sea Basin as a whole - that is, the rivers Syr Darya, Amu Darya, Kashkadarya, and Zarafshan, as well as the Aral Sea. The model representation includes water resources, including 14 river sections, 6 terminal lakes, 28 reservoirs and 19 catchment runoff nodes, as well as land resources (i.e., irrigated croplands). The model covers 5 sectors: agriculture (crops: wheat, cotton, alfalfa, rice, fruit, vegetables and others), hydropower, nature, households and industry. The focus of the model is on welfare impacts associated with changes to water use in the agriculture and hydropower sectors. The model aims at addressing the following issues of relevance for economic management of water resources: • Physical efficiency (estimating how investments in irrigation efficiency affect economic welfare). • Economic efficiency (estimating how changes in how water is allocated affect welfare). • Equity (who will gain from changes in allocation of water from one sector to another and who will lose?). Stakeholders in the region have been involved in the development of the model, and about 10 national experts, including

  11. The Vesicle Protein SAM-4 Regulates the Processivity of Synaptic Vesicle Transport

    PubMed Central

    Zheng, Qun; Ahlawat, Shikha; Schaefer, Anneliese; Mahoney, Tim; Koushika, Sandhya P.; Nonet, Michael L.

    2014-01-01

    Axonal transport of synaptic vesicles (SVs) is a KIF1A/UNC-104 mediated process critical for synapse development and maintenance yet little is known of how SV transport is regulated. Using C. elegans as an in vivo model, we identified SAM-4 as a novel conserved vesicular component regulating SV transport. Processivity, but not velocity, of SV transport was reduced in sam-4 mutants. sam-4 displayed strong genetic interactions with mutations in the cargo binding but not the motor domain of unc-104. Gain-of-function mutations in the unc-104 motor domain, identified in this study, suppress the sam-4 defects by increasing processivity of the SV transport. Genetic analyses suggest that SAM-4, SYD-2/liprin-α and the KIF1A/UNC-104 motor function in the same pathway to regulate SV transport. Our data support a model in which the SV protein SAM-4 regulates the processivity of SV transport. PMID:25329901

  12. [Model for the regional allocation of the National Health Care Fund].

    PubMed

    Loreti, P; Muzzi, A; Bruni, G

    1989-01-01

    In 1978 a National Health Service (Servizio Sanitario Nazionale = SSN) was constituted in Italy which exercises jurisdiction in the sector of health care and is duty bound to assist all citizens. Basically speaking, the NHS is organized on three levels (national, regional and local) with the management of direct operations assigned to the (about 700) Local Health Boards (Unità Sanitaria Locale = USL) each of which covers a well determined territorial area. The Authors indicate that rarely discussed or evaluated are the procedures for the regional allocation of health care funding which is determined by Parliament within the ambit of the National Budget (The National Health Care Fund). The current allocation model distributes the available capital resources for each expense item (e.g. hospitalization, pharmaceutical assistance, etc.) on a per capita basis with respect to the regional populations modified in order to allow for differing degrees of health care requirements. The regional populations are subdivided into broad age groups (e.g. children, intermediary, the elderly) with specific weighting factors expressing the different level of health care requirements. The application of these weighting factors alters the regional populations (with no change in the total population of the country) in order to express them in equivalent units with respect to the health care need. Moreover, standardized death rates are introduced into the model as indicators of the different health risk, and their application leads to a further modification in the level of the regional populations so as to express them in equivalent units with respect to the health risk as well. Once the available financial resources have been subdivided in this "theoretical" way, the following corrective factors are applied: a) hospital mobility correction factor: the regions with a credit admissions balance are assigned an additional cost which is borne by the regions with a debit admissions balance; b

  13. Comparing administered and market-based water allocation systems using an agent-based modeling approach

    NASA Astrophysics Data System (ADS)

    Zhao, J.; Cai, X.; Wang, Z.

    2009-12-01

    It also has been well recognized that market-based systems can have significant advantages over administered systems for water allocation. However there are not many successful water markets around the world yet and administered systems exist commonly in water allocation management practice. This paradox has been under discussion for decades and still calls for attention for both research and practice. This paper explores some insights for the paradox and tries to address why market systems have not been widely implemented for water allocation. Adopting the theory of agent-based system we develop a consistent analytical model to interpret both systems. First we derive some theorems based on the analytical model, with respect to the necessary conditions for economic efficiency of water allocation. Following that the agent-based model is used to illustrate the coherence and difference between administered and market-based systems. The two systems are compared from three aspects: 1) the driving forces acting on the system state, 2) system efficiency, and 3) equity. Regarding economic efficiency, penalty on the violation of water use permits (or rights) under an administered system can lead to system-wide economic efficiency, as well as being acceptable by some agents, which follows the theory of the so-call rational violation. Ideal equity will be realized if penalty equals incentive with an administered system and if transaction costs are zero with a market system. The performances of both agents and the over system are explained with an administered system and market system, respectively. The performances of agents are subject to different mechanisms of interactions between agents under the two systems. The system emergency (i.e., system benefit, equilibrium market price, etc), resulting from the performance at the agent level, reflects the different mechanism of the two systems, the “invisible hand” with the market system and administrative measures (penalty

  14. Modelling the effect of environmental factors on resource allocation in mixed plants systems

    NASA Astrophysics Data System (ADS)

    Gayler, Sebastian; Priesack, Eckart

    2010-05-01

    In most cases, growth of plants is determined by competition against neighbours for the local resources light, water and nutrients and by defending against herbivores and pathogens. Consequently, it is important for a plant to grow fast without neglecting defence. However, plant internal substrates and energy required to support maintenance, growth and defence are limited and the total demand for these processes cannot be met in most cases. Therefore, allocation of carbohydrates to growth related primary metabolism or to defence related secondary metabolism can be seen as a trade-off between the demand of plants for being competitive against neighbours and for being more resistant against pathogens. A modelling approach is presented which can be used to simulate competition for light, water and nutrients between plant individuals in mixed canopies. The balance of resource allocation between growth processes and synthesis of secondary compounds is modelled by a concept originating from different plant defence hypothesis. The model is used to analyse the impact of environmental factors such as soil water and nitrogen availability, planting density and atmospheric concentration of CO2 on growth of plant individuals within mixed canopies and variations in concentration of carbon-based secondary metabolites in plant tissues.

  15. SAMS Acceleration Measurements on MIR

    NASA Technical Reports Server (NTRS)

    Moskowitz, Milton E.; Hrovat, Kenneth; Finkelstein, Robert; Reckart, Timothy

    1997-01-01

    During NASA Increment 3 (September 1996 to January 1997), about 5 gigabytes of acceleration data were collected by the Space Acceleration Measurement System (SAMS) onboard the Russian Space Station, Mir. The data were recorded on 11 optical disks and were returned to Earth on STS-81. During this time, SAMS data were collected in the Priroda module to support the following experiments: the Mir Structural Dynamics Experiment (MiSDE) and Binary Colloidal Alloy Tests (BCAT). This report points out some of the salient features of the microgravity environment to which these experiments were exposed. Also documented are mission events of interest such as the docked phase of STS-81 operations, a Progress engine burn, attitude control thruster operation, and crew exercise. Also included are a description of the Mir module orientations, and the panel notations within the modules. This report presents an overview of the SAMS acceleration measurements recorded by 10 Hz and 100 Hz sensor heads. Variations in the acceleration environment caused by unique activities such as crew exercise and life-support fans are presented. The analyses included herein complement those presented in previous mission summary reports published by the Principal Investigator Microgravity Services (PIMS) group.

  16. A New Model for Equitable and Efficient Resource Allocation to Schools: The Israeli Case

    ERIC Educational Resources Information Center

    BenDavid-Hadar, Iris; Ziderman, Adrian

    2011-01-01

    This paper sets out a new budget allocation formula for schools, designed to achieve a more equitable distribution of educational achievement. In addition to needs-based elements, the suggested composite allocation formula includes an improvement component, whereby schools receive budgetary allocations based on a new incentive measure developed in…

  17. Spatial evaluation of crop maps by the spatial production allocation model in China

    NASA Astrophysics Data System (ADS)

    Tan, Jieyang; Li, Zhengguo; Yang, Peng; Yu, Qiangyi; Zhang, Li; Wu, Wenbin; Tang, Pengqin; Liu, Zhenhuan; You, Liangzhi

    2014-01-01

    The spatial production allocation model (SPAM) is one of the broadest spatial models of crop distribution and applies a cross-entropy method to downscale the global area and yield for multiple crops in the years 2000 and 2005 with a resolution of 5 arc min. To evaluate the allocation accuracy of SPAM for three staple crops (rice, wheat, and maize) in China, we compared these crop maps with remote-sensed cropland data derived from national land cover datasets. This comparison was conducted using a scheme that accounts for spatial differences at the pixel level. Overall, the map of maize has the highest area accuracy, with 64% reasonable pixels (covering 96% of the total maize area); these values were 57% (90% coverage) and 44% (81% coverage) for the wheat and rice maps, respectively. On the provincial scale, the area accuracies of crop maps in the top 10 provinces are better than those of the other provinces. Furthermore, the crop area consistency in rain-fed cropland is better than that in irrigated cropland. These evaluations provide decision makers with information regarding the strengths and weaknesses of SPAM products. This study also recommends priorities for further work to improve the reliability, utility, and periodic repeatability of crop distribution products.

  18. Decomposing biodiversity data using the Latent Dirichlet Allocation model, a probabilistic multivariate statistical method

    PubMed Central

    Valle, Denis; Baiser, Benjamin; Woodall, Christopher W; Chazdon, Robin

    2014-01-01

    We propose a novel multivariate method to analyse biodiversity data based on the Latent Dirichlet Allocation (LDA) model. LDA, a probabilistic model, reduces assemblages to sets of distinct component communities. It produces easily interpretable results, can represent abrupt and gradual changes in composition, accommodates missing data and allows for coherent estimates of uncertainty. We illustrate our method using tree data for the eastern United States and from a tropical successional chronosequence. The model is able to detect pervasive declines in the oak community in Minnesota and Indiana, potentially due to fire suppression, increased growing season precipitation and herbivory. The chronosequence analysis is able to delineate clear successional trends in species composition, while also revealing that site-specific factors significantly impact these successional trajectories. The proposed method provides a means to decompose and track the dynamics of species assemblages along temporal and spatial gradients, including effects of global change and forest disturbances. PMID:25328064

  19. Decomposing biodiversity data using the Latent Dirichlet Allocation model, a probabilistic multivariate statistical method.

    PubMed

    Valle, Denis; Baiser, Benjamin; Woodall, Christopher W; Chazdon, Robin

    2014-12-01

    We propose a novel multivariate method to analyse biodiversity data based on the Latent Dirichlet Allocation (LDA) model. LDA, a probabilistic model, reduces assemblages to sets of distinct component communities. It produces easily interpretable results, can represent abrupt and gradual changes in composition, accommodates missing data and allows for coherent estimates of uncertainty. We illustrate our method using tree data for the eastern United States and from a tropical successional chronosequence. The model is able to detect pervasive declines in the oak community in Minnesota and Indiana, potentially due to fire suppression, increased growing season precipitation and herbivory. The chronosequence analysis is able to delineate clear successional trends in species composition, while also revealing that site-specific factors significantly impact these successional trajectories. The proposed method provides a means to decompose and track the dynamics of species assemblages along temporal and spatial gradients, including effects of global change and forest disturbances. PMID:25328064

  20. Perceptions and Attitudes of Health Professionals in Kenya on National Health Care Resource Allocation Mechanisms: A Structural Equation Modeling

    PubMed Central

    Owili, Patrick Opiyo; Hsu, Yi-Hsin Elsa; Chern, Jin-Yuan; Chiu, Chiung-Hsuan Megan; Wang, Bill; Huang, Kuo-Cherh; Muga, Miriam Adoyo

    2015-01-01

    Background Health care resource allocation is key towards attaining equity in the health system. However, health professionals’ perceived impact and attitude towards health care resource allocation in Sub-Saharan Africa is unknown; furthermore, they occupy a position which makes them notice the impact of different policies in their health system. This study explored perceptions and attitudes of health professionals in Kenya on health care resource allocation mechanism. Method We conducted a survey of a representative sample of 341 health professionals in Moi Teaching and Referral Hospital from February to April 2012, consisting of over 3000 employees. We assessed health professionals’ perceived impact and attitudes on health care resource allocation mechanism in Kenya. We used structural equation modeling and applied a Confirmatory Factor Analysis using Robust Maximum Likelihood estimation procedure to test the hypothesized model. Results We found that the allocation mechanism was negatively associated with their perceived positive impact (-1.04, p < .001), health professionals’ satisfaction (-0.24, p < .01), and professionals’ attitudes (-1.55, p < .001) while it was positively associated with perceived negative impact (1.14, p < .001). Perceived positive impact of the allocation mechanism was negatively associated with their overall satisfaction (-0.08) and attitude (-0.98) at p < .001, respectively. Furthermore, overall satisfaction was negatively associated with attitude (-1.10, p <.001). On the other hand, perceived negative impact of the allocation was positively associated with overall satisfaction (0.29, p <.001) but was not associated with attitude. Conclusion The result suggests that health care resource allocation mechanism has a negative effect towards perceptions, attitudes and overall satisfaction of health professionals who are at the frontline in health care. These findings can serve as a crucial reference for policymakers as the Kenyan

  1. Concurrent airline fleet allocation and aircraft design with profit modeling for multiple airlines

    NASA Astrophysics Data System (ADS)

    Govindaraju, Parithi

    A "System of Systems" (SoS) approach is particularly beneficial in analyzing complex large scale systems comprised of numerous independent systems -- each capable of independent operations in their own right -- that when brought in conjunction offer capabilities and performance beyond the constituents of the individual systems. The variable resource allocation problem is a type of SoS problem, which includes the allocation of "yet-to-be-designed" systems in addition to existing resources and systems. The methodology presented here expands upon earlier work that demonstrated a decomposition approach that sought to simultaneously design a new aircraft and allocate this new aircraft along with existing aircraft in an effort to meet passenger demand at minimum fleet level operating cost for a single airline. The result of this describes important characteristics of the new aircraft. The ticket price model developed and implemented here enables analysis of the system using profit maximization studies instead of cost minimization. A multiobjective problem formulation has been implemented to determine characteristics of a new aircraft that maximizes the profit of multiple airlines to recognize the fact that aircraft manufacturers sell their aircraft to multiple customers and seldom design aircraft customized to a single airline's operations. The route network characteristics of two simple airlines serve as the example problem for the initial studies. The resulting problem formulation is a mixed-integer nonlinear programming problem, which is typically difficult to solve. A sequential decomposition strategy is applied as a solution methodology by segregating the allocation (integer programming) and aircraft design (non-linear programming) subspaces. After solving a simple problem considering two airlines, the decomposition approach is then applied to two larger airline route networks representing actual airline operations in the year 2005. The decomposition strategy serves

  2. A New Model for Redundancy Allocation Problem in Series Systems with Repairable Components by Genetic Algorithm

    NASA Astrophysics Data System (ADS)

    Sharifi, Mani; Rezaei Moayed, Reza; Haratizadeh, Sara

    2011-09-01

    This paper presents two models for redundancy allocation problem (RAP) with cold standby redundancy policy subject to weight and cost constraints. Also, each element of the system can be damaged exponentially. And, damaged elements can be repaired exponentially by hiring some repairmen. The problem is to determine: (1) element type used in the system, (2) number of elements, and (3) number of repairmen. As the models are not solvable by exact solution methods in reasonable CPU time, an efficient genetic algorithm is developed for it. The genetic algorithm (GA) is hybridized with a local search procedure. Also, the algorithm accepts infeasible solutions after penalizing them based on their amounts of infeasibilities. Thereby, by using these two features, an efficient genetic algorithm is obtained.

  3. Statistical mechanics of competitive resource allocation using agent-based models

    NASA Astrophysics Data System (ADS)

    Chakraborti, Anirban; Challet, Damien; Chatterjee, Arnab; Marsili, Matteo; Zhang, Yi-Cheng; Chakrabarti, Bikas K.

    2015-01-01

    Demand outstrips available resources in most situations, which gives rise to competition, interaction and learning. In this article, we review a broad spectrum of multi-agent models of competition (El Farol Bar problem, Minority Game, Kolkata Paise Restaurant problem, Stable marriage problem, Parking space problem and others) and the methods used to understand them analytically. We emphasize the power of concepts and tools from statistical mechanics to understand and explain fully collective phenomena such as phase transitions and long memory, and the mapping between agent heterogeneity and physical disorder. As these methods can be applied to any large-scale model of competitive resource allocation made up of heterogeneous adaptive agent with non-linear interaction, they provide a prospective unifying paradigm for many scientific disciplines.

  4. Sam.

    ERIC Educational Resources Information Center

    Wilson, James C.

    1988-01-01

    A father writes about his six-year-old son born with hydrocephalus. He describes such day-to-day experiences as going to a baseball game and the grocery store, reactions of friends and strangers to his son's social interactions, and a special day at preschool. The boy's medical treatment, including surgeries, are also described. (VW)

  5. Sam37 is crucial for formation of the mitochondrial TOM–SAM supercomplex, thereby promoting β-barrel biogenesis

    PubMed Central

    Wenz, Lena-Sophie; Ellenrieder, Lars; Qiu, Jian; Bohnert, Maria; Zufall, Nicole; van der Laan, Martin; Becker, Thomas

    2015-01-01

    Biogenesis of mitochondrial β-barrel proteins requires two preprotein translocases, the general translocase of the outer membrane (TOM) and the sorting and assembly machinery (SAM). TOM and SAM form a supercomplex that promotes transfer of β-barrel precursors. The SAM core complex contains the channel protein Sam50, which cooperates with Sam35 in precursor recognition, and the peripheral membrane protein Sam37. The molecular function of Sam37 has been unknown. We report that Sam37 is crucial for formation of the TOM–SAM supercomplex. Sam37 interacts with the receptor domain of Tom22 on the cytosolic side of the mitochondrial outer membrane and links TOM and SAM complexes. Sam37 thus promotes efficient transfer of β-barrel precursors to the SAM complex. We conclude that Sam37 functions as a coupling factor of the translocase supercomplex of the mitochondrial outer membrane. PMID:26416958

  6. SAM -- A Spectral Extraction Package

    NASA Astrophysics Data System (ADS)

    Lewis, J. R.

    In this note a description is given of SAM, a package written at RGO for the extraction of spectra from two dimensional data frames. The need to extract spectra from two dimensional frames in an optimal manner (e.g. one in which the signal to noise ratio was maximised) was the primary reason for the writing of the package. The programs were originally written with FOS, ISIS and IDS in mind, but contain nothing which is instrument specific and hence should be applicable to any two dimensional spectral data frame.

  7. Context dependence of maternal effects: testing assumptions of optimal egg size, differential, and sex allocation models.

    PubMed

    Krist, Miloš; Munclinger, Pavel

    2015-10-01

    If offspring develop in adverse conditions, the maternal component of their phenotypic variation might increase due to the stronger dependence of offspring traits on parental investment. This should result in increased parental investment to individual offspring, as assumed by the model of optimal egg size. The opposite pattern, i.e., stronger dependence of offspring fitness on parental investment and consequently larger parental investment under good conditions is assumed by both the theory of differential allocation if attractive males provide material benefits, and reproductive compensation if they invest less into paternal care. Another influential idea is the Trivers-Willard model, which assumes sex-specific dependence of offspring fitness on parental investment. Here we tested these ideas by examining the effects of egg size on offspring fitness across many postnatal contexts in the Collared Flycatcher Ficedula albicollis. We employed a cross-fostering design that generated variation in egg size within nests and used brood means of fledgling mass as a functional measure of the quality of rearing conditions. Effects of egg size on three offspring traits, including lifetime reproductive success of recruits, were more pronounced in low-quality broods. These results support the assumption of the model of optimal egg size. Based on female preference for males providing material benefits, this pattern could support differential allocation, if attractive males invest less in paternal care, or reproductive compensation, if they invest more. By comparison, we did not find any evidence for sex specificity of fitness returns that might explain sex monomorphism of egg size in this species. The challenge for future studies will be the integration of components of parental investment and offspring fitness into their global measures and testing how the former affects the latter across gradients of postnatal conditions. PMID:26649393

  8. Does Distraction Reduce the Alcohol-Aggression Relation? A Cognitive and Behavioral Test of the Attention-Allocation Model

    ERIC Educational Resources Information Center

    Gallagher, Kathryn E.; Parrott, Dominic J.

    2011-01-01

    Objective: This study provided the first direct test of the cognitive underpinnings of the attention-allocation model and attempted to replicate and extend past behavioral findings for this model as an explanation for alcohol-related aggression. Method: A diverse community sample (55% African American) of men (N = 159) between 21 and 35 years of…

  9. Water allocation for agriculture in southwestern Iran using a programming model

    NASA Astrophysics Data System (ADS)

    Esmaeili, Abdoulkarim; Shahsavari, Zahra

    2015-09-01

    Water pricing can play a major role in improving water allocation, encouraging users to conserve scarce water resources, and promoting improvements in productivity. In this study, the economic values of water in farms under Dorodzan Dam in southwestern Iran were calculated using linear programming models. The method was applied to three samples of farms that drew irrigation water from a canal, a well, and both a well and a canal. The results of this study revealed that the shadow prices of water in farms varied based on the water sources and time of year. Additionally, the estimated price for water is obviously higher than the price that farmers currently pay for water in the study area. Due to the different economic values of water calculated for different months, it is recommended that the price of irrigation water be adjusted accordingly during various seasons in a fashion similar to that of electrical energy.

  10. A Schelling model with switching agents: decreasing segregation via random allocation and social mobility

    NASA Astrophysics Data System (ADS)

    Hazan, Aurélien; Randon-Furling, Julien

    2013-10-01

    We study the behaviour of a Schelling-class system in which a fraction f of spatially-fixed switching agents is introduced. This new model allows for multiple interpretations, including: (i) random, non-preferential allocation (e.g. by housing associations) of given, fixed sites in an open residential system, and (ii) superimposition of social and spatial mobility in a closed residential system. We find that the presence of switching agents in a segregative Schelling-type dynamics can lead to the emergence of intermediate patterns (e.g. mixture of patches, fuzzy interfaces) as the ones described in [E. Hatna, I. Benenson, J. Artif. Soc. Social. Simul. 15, 6 (2012)]. We also investigate different transitions between segregated and mixed phases both at f = 0 and along lines of increasing f, where the nature of the transition changes.

  11. Optimizing Real-Time Vaccine Allocation in a Stochastic SIR Model

    PubMed Central

    Nguyen, Chantal; Carlson, Jean M.

    2016-01-01

    Real-time vaccination following an outbreak can effectively mitigate the damage caused by an infectious disease. However, in many cases, available resources are insufficient to vaccinate the entire at-risk population, logistics result in delayed vaccine deployment, and the interaction between members of different cities facilitates a wide spatial spread of infection. Limited vaccine, time delays, and interaction (or coupling) of cities lead to tradeoffs that impact the overall magnitude of the epidemic. These tradeoffs mandate investigation of optimal strategies that minimize the severity of the epidemic by prioritizing allocation of vaccine to specific subpopulations. We use an SIR model to describe the disease dynamics of an epidemic which breaks out in one city and spreads to another. We solve a master equation to determine the resulting probability distribution of the final epidemic size. We then identify tradeoffs between vaccine, time delay, and coupling, and we determine the optimal vaccination protocols resulting from these tradeoffs. PMID:27043931

  12. A modelization of the task allocation problem for prescribing activity in an ICU.

    PubMed Central

    Renard, J. M.; Bricon-Souf, N.; Guigue, L.; Beuscart, R.

    2000-01-01

    The improvement of coordination between Health Care Professionals belonging different specialities and who are extremely mobile, is a crucial problem in Medicine. A workflow System is one example of the new informatics tools which facilitate the transfer of information and responsibility between health care providers. Medical informatics systems in particular should be reactive enough to cope with the flexibility of real work situations: in this paper, we present the task allocation problem. We distinguish between the workflow control process and the notifying process, which concerns the sharing out of the tasks between the actors concerned. We focus on the impact of strategies of notification on the progress of coordinated work. We propose a simulator to model and study the different ways of sharing tasks between actors in an Intensive Care Unit's activity of prescription. PMID:11079971

  13. Determining the robust counterpart of uncertain spatial optimization model for water supply allocation problem

    NASA Astrophysics Data System (ADS)

    Chaerani, D.; Ruchjana, B. N.; Dewanto, S. P.; Abdullah, A. S.; Rejito, J.; Rosandi, Y.; Dharmawan, I. A.

    2016-02-01

    In this paper we discuss how to get the robust counterpart for the spatial optimization model for water supply allocation (SOMWSA) problem that is proposed by [6]. We employ the robust counterpart methodology that is proposed by Ben-Tal and Nemirovskii [2] also use the new paradigm of robust counterpart methodology of den Hertog et al. [4]. To this end, first we define the uncertain family class of SOMWSA and derive the robust version of the uncertain problem. We assume that there are two uncertain data in SOMWSA problem, ie., the total population and the water demand in a region i at time t. Since the tractability of the problem is very important in Robust Optimization, we discuss three types of uncertainty set, i.e., box, ellipsoidal and polyhedral uncertainty set.

  14. Exact performance analytical model for spectrum allocation in flexible grid optical networks

    NASA Astrophysics Data System (ADS)

    Yu, Yiming; Zhang, Jie; Zhao, Yongli; Li, Hui; Ji, Yuefeng; Gu, Wanyi

    2014-03-01

    Dynamic flexible grid optical networks have gained much attention because of the advantages of high spectrum efficiency and flexibility, while the performance analysis will be more complex compared with fixed grid optical networks. An analytical Markov model is first presented in the paper, which can exactly describe the stochastic characteristics of the spectrum allocation in flexible grid optical networks considering both random-fit and first-fit resource assignment policies. We focus on the effect of spectrum contiguous constraint which has not been systematically studied in respect of mathematical modeling, and three major properties of the model are presented and analyzed. The model can expose key performance features and act as the foundation of modeling the Routing and Spectrum Assignment (RSA) problem with diverse topologies. Two heuristic algorithms are also proposed to make it more tractable. Finally, several key parameters, such as blocking probability, resource utilization rate and fragmentation rate are presented and computed, and the corresponding Monte Carlo simulation results match closely with analytical results, which prove the correctness of this mathematical model.

  15. Competitive allocation of resources on a network: an agent-based model of air companies competing for the best routes

    NASA Astrophysics Data System (ADS)

    Gurtner, Gérald; Valori, Luca; Lillo, Fabrizio

    2015-05-01

    We present a stylized model of the allocation of resources on a network. By considering as a concrete example the network of sectors of the airspace, where each node is a sector characterized by a maximal number of simultaneously present aircraft, we consider the problem of air companies competing for the allocation of the airspace. Each company is characterized by a cost function, weighting differently punctuality and length of the flight. We consider the model in the presence of pure and mixed populations of types of airline companies and we study how the equilibria depends on the characteristics of the network.

  16. Location-allocation and accessibility models for improving the spatial planning of public health services.

    PubMed

    Polo, Gina; Acosta, C Mera; Ferreira, Fernando; Dias, Ricardo Augusto

    2015-01-01

    This study integrated accessibility and location-allocation models in geographic information systems as a proposed strategy to improve the spatial planning of public health services. To estimate the spatial accessibility, we modified the two-step floating catchment area (2SFCA) model with a different impedance function, a Gaussian weight for competition among service sites, a friction coefficient, distances along a street network based on the Dijkstra's algorithm and by performing a vectorial analysis. To check the accuracy of the strategy, we used the data from the public sterilization program for the dogs and cats of Bogot´a, Colombia. Since the proposed strategy is independent of the service, it could also be applied to any other public intervention when the capacity of the service is known. The results of the accessibility model were consistent with the sterilization program data, revealing that the western, central and northern zones are the most isolated areas under the sterilization program. Spatial accessibility improvement was sought by relocating the sterilization sites using the maximum coverage with finite demand and the p-median models. The relocation proposed by the maximum coverage model more effectively maximized the spatial accessibility to the sterilization service given the non-uniform distribution of the populations of dogs and cats throughout the city. The implementation of the proposed strategy would provide direct benefits by improving the effectiveness of different public health interventions and the use of financial and human resources. PMID:25775411

  17. Location-Allocation and Accessibility Models for Improving the Spatial Planning of Public Health Services

    PubMed Central

    Polo, Gina; Acosta, C. Mera; Ferreira, Fernando; Dias, Ricardo Augusto

    2015-01-01

    This study integrated accessibility and location-allocation models in geographic information systems as a proposed strategy to improve the spatial planning of public health services. To estimate the spatial accessibility, we modified the two-step floating catchment area (2SFCA) model with a different impedance function, a Gaussian weight for competition among service sites, a friction coefficient, distances along a street network based on the Dijkstra’s algorithm and by performing a vectorial analysis. To check the accuracy of the strategy, we used the data from the public sterilization program for the dogs and cats of Bogot´a, Colombia. Since the proposed strategy is independent of the service, it could also be applied to any other public intervention when the capacity of the service is known. The results of the accessibility model were consistent with the sterilization program data, revealing that the western, central and northern zones are the most isolated areas under the sterilization program. Spatial accessibility improvement was sought by relocating the sterilization sites using the maximum coverage with finite demand and the p-median models. The relocation proposed by the maximum coverage model more effectively maximized the spatial accessibility to the sterilization service given the non-uniform distribution of the populations of dogs and cats throughout the city. The implementation of the proposed strategy would provide direct benefits by improving the effectiveness of different public health interventions and the use of financial and human resources. PMID:25775411

  18. Determination of cost coefficients of a priority-based water allocation linear programming model - a network flow approach

    NASA Astrophysics Data System (ADS)

    Chou, F. N.-F.; Wu, C.-W.

    2014-05-01

    This paper presents a method to establish the objective function of a network flow programming model for simulating river-reservoir system operations and associated water allocation, with an emphasis on situations when the links other than demand or storage have to be assigned with nonzero cost coefficients. The method preserves the priorities defined by rule curves of reservoir, operational preferences for conveying water, allocation of storage among multiple reservoirs, and transbasin water diversions. Path enumeration analysis transforms these water allocation rules into linear constraints that can be solved to determine link cost coefficients. An approach to prune the original system into a reduced network is proposed to establish the precise constraints of nonzero cost coefficients, which can then be efficiently solved. The cost coefficients for the water allocation in the Feitsui and Shihmen reservoirs' joint operating system of northern Taiwan was adequately assigned by the proposed method. This case study demonstrates how practitioners can correctly utilize network-flow-based models to allocate water supply throughout complex systems that are subject to strict operating rules.

  19. Determination of cost coefficients of priority-based water allocation linear programming model - a network flow approach

    NASA Astrophysics Data System (ADS)

    Chou, F. N.-F.; Wu, C.-W.

    2013-12-01

    This paper presents a method to establish the objective function of a network flow programming model for simulating river/reservoir system operations and associated water allocation, with an emphasis on situations when the links other than demand or storage have to be assigned with nonzero cost coefficients. The method preserves the priorities defined by rule curves of reservoir, operational preferences for conveying water, allocation of storage among multiple reservoirs, and trans-basin water diversions. Path enumeration analysis transforms these water allocation rules into linear constraints that can be solved to determine link cost coefficients. An approach to prune the original system into a reduced network is proposed to establish the precise constraints of nonzero cost coefficients which can then be efficiently solved. The cost coefficients for the water allocation in the Feitsui and Shihmen Reservoirs joint operating system of northern Taiwan was adequately assigned by the proposed method. This case study demonstrates how practitioners can correctly utilize network-flow-based models to allocate water supply throughout complex systems that are subject to strict operating rules.

  20. Simulation of tree ring-widths with a model for primary production, carbon allocation and growth

    NASA Astrophysics Data System (ADS)

    Li, G.; Harrison, S. P.; Prentice, I. C.; Falster, D.

    2014-07-01

    We present a simple, generic model of annual tree growth, called "T". This model accepts input from a first-principles light-use efficiency model (the P model). The P model provides values for Gross Primary Production (GPP) per unit of absorbed photosynthetically active radiation (PAR). Absorbed PAR is estimated from the current leaf area. GPP is allocated to foliage, transport-tissue, and fine root production and respiration, in such a way as to satisfy well-understood dimensional and functional relationships. Our approach thereby integrates two modelling approaches separately developed in the global carbon-cycle and forest-science literature. The T model can represent both ontogenetic effects (impact of ageing) and the effects of environmental variations and trends (climate and CO2) on growth. Driven by local climate records, the model was applied to simulate ring widths during 1958-2006 for multiple trees of Pinus koraiensis from the Changbai Mountain, northeastern China. Each tree was initialised at its actual diameter at the time when local climate records started. The model produces realistic simulations of the interannual variability in ring width for different age cohorts (young, mature, old). Both the simulations and observations show a significant positive response of tree-ring width to growing-season total photosynthetically active radiation (PAR0) and the ratio of actual to potential evapotranspiration (α), and a significant negative response to mean annual temperature (MAT). The slopes of the simulated and observed relationships with PAR0 and α are similar; the negative response to MAT is underestimated by the model. Comparison of simulations with fixed and changing atmospheric CO2 concentration shows that CO2 fertilization over the past 50 years is too small to be distinguished in the ring-width data given ontogenetic trends and interannual variability in climate.

  1. Simulation of tree-ring widths with a model for primary production, carbon allocation, and growth

    NASA Astrophysics Data System (ADS)

    Li, G.; Harrison, S. P.; Prentice, I. C.; Falster, D.

    2014-12-01

    We present a simple, generic model of annual tree growth, called "T". This model accepts input from a first-principles light-use efficiency model (the "P" model). The P model provides values for gross primary production (GPP) per unit of absorbed photosynthetically active radiation (PAR). Absorbed PAR is estimated from the current leaf area. GPP is allocated to foliage, transport tissue, and fine-root production and respiration in such a way as to satisfy well-understood dimensional and functional relationships. Our approach thereby integrates two modelling approaches separately developed in the global carbon-cycle and forest-science literature. The T model can represent both ontogenetic effects (the impact of ageing) and the effects of environmental variations and trends (climate and CO2) on growth. Driven by local climate records, the model was applied to simulate ring widths during the period 1958-2006 for multiple trees of Pinus koraiensis from the Changbai Mountains in northeastern China. Each tree was initialised at its actual diameter at the time when local climate records started. The model produces realistic simulations of the interannual variability in ring width for different age cohorts (young, mature, and old). Both the simulations and observations show a significant positive response of tree-ring width to growing-season total photosynthetically active radiation (PAR0) and the ratio of actual to potential evapotranspiration (α), and a significant negative response to mean annual temperature (MAT). The slopes of the simulated and observed relationships with PAR0 and α are similar; the negative response to MAT is underestimated by the model. Comparison of simulations with fixed and changing atmospheric CO2 concentration shows that CO2 fertilisation over the past 50 years is too small to be distinguished in the ring-width data, given ontogenetic trends and interannual variability in climate.

  2. SAM-2 ground-truth plan: Correlative measurements for the Stratospheric Aerosol Measurement-2 (SAM 2) sensor on the Nimbus G satellite

    NASA Technical Reports Server (NTRS)

    Russell, P. B.; Mccormick, M. P.; Mcmaster, L. R.; Pepin, T. J.; Chu, W. P.; Swissler, T. J.

    1978-01-01

    The SAM-2 will fly aboard the Nimbus-G satellite for launch in the fall of 1978 and measure stratospheric vertical profiles of aerosol extinction in high latitude bands. The plan gives details of the location and times for the simultaneous satellite/correlative measurements for the nominal launch time, the rationale and choice of the correlative sensors, their characteristics and expected accuracies, and the conversion of their data to extinction profiles. The SAM-2 expected instrument performance and data inversion results are presented. Various atmospheric models representative of polar stratospheric aerosols are used in the SAM-2 and correlative sensor analyses.

  3. Modeling Resources Allocation in Attacker-Defender Games with "Warm Up" CSF.

    PubMed

    Guan, Peiqiu; Zhuang, Jun

    2016-04-01

    Like many other engineering investments, the attacker's and defender's investments may have limited impact without initial capital to "warm up" the systems. This article studies such "warm up" effects on both the attack and defense equilibrium strategies in a sequential-move game model by developing a class of novel and more realistic contest success functions. We first solve a single-target attacker-defender game analytically and provide numerical solutions to a multiple-target case. We compare the results of the models with and without consideration of the investment "warm up" effects, and find that the defender would suffer higher expected damage, and either underestimate the attacker effort or waste defense investment if the defender falsely believes that no investment "warm up" effects exist. We illustrate the model results with real data, and compare the results of the models with and without consideration of the correlation between the "warm up" threshold and the investment effectiveness. Interestingly, we find that the defender is suggested to give up defending all the targets when the attack or the defense "warm up" thresholds are sufficiently high. This article provides new insights and suggestions on policy implications for homeland security resource allocation. PMID:26713543

  4. Understanding the Electronic Structure of Metal/SAM/Organic−Semiconductor Heterojunctions

    PubMed Central

    2009-01-01

    Computational modeling is used to describe the mechanisms governing energy level alignment between an organic semiconductor (OSC) and a metal covered by various self-assembled monolayers (SAMs). In particular, we address the question to what extent and under what circumstances SAM-induced work-function modifications lead to an actual change of the barriers for electron and hole injection from the metal into the OSC layer. Depending on the nature of the SAM, we observe clear transitions between Fermi level pinning and vacuum-level alignment regimes. Surprisingly, although in most cases the pinning occurs only when the metal is present, it is not related to charge transfer between the electrode and the organic layer. Instead, charge rearrangements at the interface between the SAM and the OSC are observed, accompanied by a polarization of the SAM. PMID:19891441

  5. Modeling virtual organizations with Latent Dirichlet Allocation: a case for natural language processing.

    PubMed

    Gross, Alexander; Murthy, Dhiraj

    2014-10-01

    This paper explores a variety of methods for applying the Latent Dirichlet Allocation (LDA) automated topic modeling algorithm to the modeling of the structure and behavior of virtual organizations found within modern social media and social networking environments. As the field of Big Data reveals, an increase in the scale of social data available presents new challenges which are not tackled by merely scaling up hardware and software. Rather, they necessitate new methods and, indeed, new areas of expertise. Natural language processing provides one such method. This paper applies LDA to the study of scientific virtual organizations whose members employ social technologies. Because of the vast data footprint in these virtual platforms, we found that natural language processing was needed to 'unlock' and render visible latent, previously unseen conversational connections across large textual corpora (spanning profiles, discussion threads, forums, and other social media incarnations). We introduce variants of LDA and ultimately make the argument that natural language processing is a critical interdisciplinary methodology to make better sense of social 'Big Data' and we were able to successfully model nested discussion topics from forums and blog posts using LDA. Importantly, we found that LDA can move us beyond the state-of-the-art in conventional Social Network Analysis techniques. PMID:24930023

  6. Interpretation of tree-ring data with a model for primary production, carbon allocation and growth

    NASA Astrophysics Data System (ADS)

    Li, G.; Wang, H.; Harrison, S. P.; Prentice, I. C.

    2013-12-01

    We present a simple, generic model of annual tree growth, called ';T'. This model accepts input from a generic light-use efficiency model which is known to provide good simulations of terrestrial carbon exchange. The light-use efficiency model provides values for Gross Primary Production (GPP) per unit of absorbed photosynthetically active radiation (PAR). Absorbed PAR is estimated from the current leaf area. GPP is allocated to foliage, transport-tissue, and fine-root production and respiration, in such a way as to satisfy well-understood dimensional relationships. The result is a model that can represent both ontogenetic effects and the effects of environmental variations and trends on growth. The model has been applied to simulate ring-width series from multiple individual trees in temperature- and drought-limited contexts. Each tree is initialized at its actual diameter at the time when local climate records started. These records are used to drive the trees' subsequent growth. Realistic simulations of the pattern of interannual variability of ring-width are generated, and shown to relate statistically to climate. An upward trend in ring-width during 1958-2007 is shown to be present in the primary observations, and in the simulations; but not in the standard, detrended ring-width series. This approach combines two modelling approaches previously developed in the global carbon cycle and forest science literature respectively. Neither has been widely applied in the context of tree-ring based climate reconstruction. This combination of methods offers promise, however, because it could provide a way to sidestep several known problems. These include: reliance on correlations for the interpretation of ring-width variations in terms of climate; the necessity of detrending using empirical functions (which can remove trends caused by variations in the environment as well as those that are ontogenetic); and the difficulty of assessing effects of extrinsic, non

  7. CARBON AND NITROGEN ALLOCATION MODEL FOR THE SUB-TROPICAL SEAGRASS THALASSIA TESTUDINUM AND THE TEMPERATE SEAGRASS ZOSTER MARINA

    EPA Science Inventory

    Our understanding of seagrass physiology is based on crude estimates of production and biomass. To better understand the complex physiological relationships between the plants and the environment we developed a model of carbon and nitrogen allocation in the sub-tropical seagrass ...

  8. Characterization of the SAM domain of the PKD-related protein ANKS6 and its interaction with ANKS3

    PubMed Central

    2014-01-01

    Background Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic disorder leading to end-stage renal failure in humans. In the PKD/Mhm(cy/+) rat model of ADPKD, the point mutation R823W in the sterile alpha motif (SAM) domain of the protein ANKS6 is responsible for disease. SAM domains are known protein-protein interaction domains, capable of binding each other to form polymers and heterodimers. Despite its physiological importance, little is known about the function of ANKS6 and how the R823W point mutation leads to PKD. Recent work has revealed that ANKS6 interacts with a related protein called ANKS3. Both ANKS6 and ANKS3 have a similar domain structure, with ankyrin repeats at the N-terminus and a SAM domain at the C-terminus. Results The SAM domain of ANKS3 is identified as a direct binding partner of the ANKS6 SAM domain. We find that ANKS3-SAM polymerizes and ANKS6-SAM can bind to one end of the polymer. We present crystal structures of both the ANKS3-SAM polymer and the ANKS3-SAM/ANKS6-SAM complex, revealing the molecular details of their association. We also learn how the R823W mutation disrupts ANKS6 function by dramatically destabilizing the SAM domain such that the interaction with ANKS3-SAM is lost. Conclusions ANKS3 is a direct interacting partner of ANKS6. By structurally and biochemically characterizing the interaction between the ANKS3 and ANKS6 SAM domains, our work provides a basis for future investigation of how the interaction between these proteins mediates kidney function. PMID:24998259

  9. A System Dynamics Model to Improve Water Resources Allocation in the Conchos River

    NASA Astrophysics Data System (ADS)

    Gastelum, J. R.; Valdes, J. B.; Stewart, S.

    2005-12-01

    The Conchos river located in Chihuahua state on a semiarid region is the most important Mexican river contributing water deliveries to USA as established by the Water treaty of 1944 signed between Mexico and USA. Historically, Mexico has delivered to UNITED STATES 550 Hm3 (445,549.5 ACF) per year of water since the treaty was established, which is 25% above the yearly water volume Mexico is required to deliver. The Conchos river has contributed with 54% of the historic Mexican water treaty deliveries to the UNITED STATES, which represents the highest percentage of the 6 Mexican rivers considered on the water treaty. However, during drought situations the basin has proven to be vulnerable, for instance, because of the severe drought of the 90's, several cities in 1992 on Chihuahua state where declared disaster areas, and from 1992 to 2001 Mexico had accumulated a water treaty deficit of 2111.6 Hm3 (1,710,586 ACF). This has conduced to economic, social, and political difficulties in both countries. Because of the cited problematic and considering the poor understanding of the relationship between water supply and demand factors on the basin, a decision support system (DSS) has been developed aimed to improve the decision making process related with the water resources allocation process. This DSS has been created using System Dynamics (SD). It is a semi-distributed model and is running on monthly time step basis. For both the short and long term, three important water resources management strategies have been evaluated: several water allocation policies from reservoirs to water users; bulk water rights transfers inside and outside Irrigation Districts; and improvement of water distribution efficiencies. The model results have provided very useful regard to gain more quantitative understanding of the different strategies being implemented. They have also indicated that the different water resources alternatives change its degree of importance according to the

  10. Global Modeling of Withdrawal, Allocation and Consumptive Use of Surface Water and Groundwater Resources

    NASA Astrophysics Data System (ADS)

    Wada, Y.; Wisser, D.; Bierkens, M. F.

    2014-12-01

    To sustain growing food demand and increasing standard of living, global water withdrawal and consumptive water use have been increasing rapidly. To analyze the human perturbation on water resources consistently over large scales, a number of macro-scale hydrological models (MHMs) have been developed in recent decades. However, few models consider the interaction between terrestrial water fluxes, and human activities and associated water use, and even fewer models distinguish water use from surface water and groundwater resources. Here, we couple a global water demand model with a global hydrological model and dynamically simulate daily water withdrawal and consumptive water use over the period 1979-2010, using two re-analysis products: ERA-Interim and MERRA. We explicitly take into account the mutual feedback between supply and demand, and implement a newly developed water allocation scheme to distinguish surface water and groundwater use. Moreover, we include a new irrigation scheme, which works dynamically with a daily surface and soil water balance, and incorporate the newly available extensive global reservoir data set (GRanD). Simulated surface water and groundwater withdrawals generally show good agreement with reported national and sub-national statistics. The results show a consistent increase in both surface water and groundwater use worldwide, with a more rapid increase in groundwater use since the 1990s. Human impacts on terrestrial water storage (TWS) signals are evident, altering the seasonal and inter-annual variability. This alteration is particularly large over heavily regulated basins such as the Colorado and the Columbia, and over the major irrigated basins such as the Mississippi, the Indus, and the Ganges. Including human water use and associated reservoir operations generally improves the correlation of simulated TWS anomalies with those of the GRACE observations.

  11. A Multi-layer Dynamic Model for Coordination Based Group Decision Making in Water Resource Allocation and Scheduling

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Zhang, Xingnan; Li, Chenming; Wang, Jianying

    Management of group decision-making is an important issue in water source management development. In order to overcome the defects in lacking of effective communication and cooperation in the existing decision-making models, this paper proposes a multi-layer dynamic model for coordination in water resource allocation and scheduling based group decision making. By introducing the scheme-recognized cooperative satisfaction index and scheme-adjusted rationality index, the proposed model can solve the problem of poor convergence of multi-round decision-making process in water resource allocation and scheduling. Furthermore, the problem about coordination of limited resources-based group decision-making process can be solved based on the effectiveness of distance-based group of conflict resolution. The simulation results show that the proposed model has better convergence than the existing models.

  12. Where does the carbon go? A model-data intercomparison of vegetation carbon allocation and turnover processes at two temperate forest free-air CO2 enrichment sites.

    PubMed

    De Kauwe, Martin G; Medlyn, Belinda E; Zaehle, Sönke; Walker, Anthony P; Dietze, Michael C; Wang, Ying-Ping; Luo, Yiqi; Jain, Atul K; El-Masri, Bassil; Hickler, Thomas; Wårlind, David; Weng, Ensheng; Parton, William J; Thornton, Peter E; Wang, Shusen; Prentice, I Colin; Asao, Shinichi; Smith, Benjamin; McCarthy, Heather R; Iversen, Colleen M; Hanson, Paul J; Warren, Jeffrey M; Oren, Ram; Norby, Richard J

    2014-08-01

    Elevated atmospheric CO2 concentration (eCO2) has the potential to increase vegetation carbon storage if increased net primary production causes increased long-lived biomass. Model predictions of eCO2 effects on vegetation carbon storage depend on how allocation and turnover processes are represented. We used data from two temperate forest free-air CO2 enrichment (FACE) experiments to evaluate representations of allocation and turnover in 11 ecosystem models. Observed eCO2 effects on allocation were dynamic. Allocation schemes based on functional relationships among biomass fractions that vary with resource availability were best able to capture the general features of the observations. Allocation schemes based on constant fractions or resource limitations performed less well, with some models having unintended outcomes. Few models represent turnover processes mechanistically and there was wide variation in predictions of tissue lifespan. Consequently, models did not perform well at predicting eCO2 effects on vegetation carbon storage. Our recommendations to reduce uncertainty include: use of allocation schemes constrained by biomass fractions; careful testing of allocation schemes; and synthesis of allocation and turnover data in terms of model parameters. Data from intensively studied ecosystem manipulation experiments are invaluable for constraining models and we recommend that such experiments should attempt to fully quantify carbon, water and nutrient budgets. PMID:24844873

  13. SAM-FS: LSC's New Solaris-Based Storage Management Product

    NASA Technical Reports Server (NTRS)

    Angell, Kent

    1996-01-01

    SAM-FS is a full featured hierarchical storage management (HSM) device that operates as a file system on Solaris-based machines. The SAM-FS file system provides the user with all of the standard UNIX system utilities and calls, and adds some new commands, i.e. archive, release, stage, sls, sfind, and a family of maintenance commands. The system also offers enhancements such as high performance virtual disk read and write, control of the disk through an extent array, and the ability to dynamically allocate block size. SAM-FS provides 'archive sets' which are groupings of data to be copied to secondary storage. In practice, as soon as a file is written to disk, SAM-FS will make copies onto secondary media. SAM-FS is a scalable storage management system. The system can manage millions of files per system, though this is limited today by the speed of UNIX and its utilities. In the future, a new search algorithm will be implemented that will remove logical and performance restrictions on the number of files managed.

  14. A multiprocessor computer simulation model employing a feedback scheduler/allocator for memory space and bandwidth matching and TMR processing

    NASA Technical Reports Server (NTRS)

    Bradley, D. B.; Irwin, J. D.

    1974-01-01

    A computer simulation model for a multiprocessor computer is developed that is useful for studying the problem of matching multiprocessor's memory space, memory bandwidth and numbers and speeds of processors with aggregate job set characteristics. The model assumes an input work load of a set of recurrent jobs. The model includes a feedback scheduler/allocator which attempts to improve system performance through higher memory bandwidth utilization by matching individual job requirements for space and bandwidth with space availability and estimates of bandwidth availability at the times of memory allocation. The simulation model includes provisions for specifying precedence relations among the jobs in a job set, and provisions for specifying precedence execution of TMR (Triple Modular Redundant and SIMPLEX (non redundant) jobs.

  15. PSOLA: A Heuristic Land-Use Allocation Model Using Patch-Level Operations and Knowledge-Informed Rules.

    PubMed

    Liu, Yaolin; Peng, Jinjin; Jiao, Limin; Liu, Yanfang

    2016-01-01

    Optimizing land-use allocation is important to regional sustainable development, as it promotes the social equality of public services, increases the economic benefits of land-use activities, and reduces the ecological risk of land-use planning. Most land-use optimization models allocate land-use using cell-level operations that fragment land-use patches. These models do not cooperate well with land-use planning knowledge, leading to irrational land-use patterns. This study focuses on building a heuristic land-use allocation model (PSOLA) using particle swarm optimization. The model allocates land-use with patch-level operations to avoid fragmentation. The patch-level operations include a patch-edge operator, a patch-size operator, and a patch-compactness operator that constrain the size and shape of land-use patches. The model is also integrated with knowledge-informed rules to provide auxiliary knowledge of land-use planning during optimization. The knowledge-informed rules consist of suitability, accessibility, land use policy, and stakeholders' preference. To validate the PSOLA model, a case study was performed in Gaoqiao Town in Zhejiang Province, China. The results demonstrate that the PSOLA model outperforms a basic PSO (Particle Swarm Optimization) in the terms of the social, economic, ecological, and overall benefits by 3.60%, 7.10%, 1.53% and 4.06%, respectively, which confirms the effectiveness of our improvements. Furthermore, the model has an open architecture, enabling its extension as a generic tool to support decision making in land-use planning. PMID:27322619

  16. PSOLA: A Heuristic Land-Use Allocation Model Using Patch-Level Operations and Knowledge-Informed Rules

    PubMed Central

    Liu, Yaolin; Peng, Jinjin; Jiao, Limin; Liu, Yanfang

    2016-01-01

    Optimizing land-use allocation is important to regional sustainable development, as it promotes the social equality of public services, increases the economic benefits of land-use activities, and reduces the ecological risk of land-use planning. Most land-use optimization models allocate land-use using cell-level operations that fragment land-use patches. These models do not cooperate well with land-use planning knowledge, leading to irrational land-use patterns. This study focuses on building a heuristic land-use allocation model (PSOLA) using particle swarm optimization. The model allocates land-use with patch-level operations to avoid fragmentation. The patch-level operations include a patch-edge operator, a patch-size operator, and a patch-compactness operator that constrain the size and shape of land-use patches. The model is also integrated with knowledge-informed rules to provide auxiliary knowledge of land-use planning during optimization. The knowledge-informed rules consist of suitability, accessibility, land use policy, and stakeholders’ preference. To validate the PSOLA model, a case study was performed in Gaoqiao Town in Zhejiang Province, China. The results demonstrate that the PSOLA model outperforms a basic PSO (Particle Swarm Optimization) in the terms of the social, economic, ecological, and overall benefits by 3.60%, 7.10%, 1.53% and 4.06%, respectively, which confirms the effectiveness of our improvements. Furthermore, the model has an open architecture, enabling its extension as a generic tool to support decision making in land-use planning. PMID:27322619

  17. NES Live Video Chat: Engineer Sam Ortega

    NASA Video Gallery

    The NES project invited all K-12 students to participate in a one-hour-long NASA video webchat on April 19, 2011 with NASA engineer Sam Ortega. Ortega answered questions about building and testing ...

  18. STS-134 Crew Talks With Sam Ting

    NASA Video Gallery

    The STS-134 crew talks with Sam Ting, principal investigator for the Alpha Magnetic Spectrometer, following the installation of the particle physics detector on the International Space Station duri...

  19. Stay lean without dieting: Lose Sam68.

    PubMed

    Huot, Marc-Étienne; Richard, Stéphane

    2012-10-01

    Alternative splicing is well known to be tissue-specific. Although several genes have been shown to undergo alternative splicing in adipocytes, little is known about the mechanism that regulates alternative splicing during adipogenesis. We recently reported that Sam68(-/-) mice exhibit a lean phenotype and are protected against diet-induced obesity. Our genome-wide exon array analysis in white adipose tissue (WAT) from wild-type and Sam68(-/-) mice revealed that Sam68 deficiency leads to an abnormal splicing of the mTOR gene. This has been shown to reduce the overall mTOR protein content and activity during in vitro adipose differentiation. In Sam68(-/-) mice, this situation leads to an increased energy expenditure, decreased adipogenesis and WAT formation. PMID:23700540

  20. Sam Donaldson: Tips from A Cancer Survivor

    MedlinePlus

    ... little bit about the disease now and the survivability of various forms and stages. Klose: Do you ... More "Understanding Cancer" Articles Understanding Cancer / Cancer Today / Survivability and Hope / Sam Donaldson: Tips From a Cancer ...

  1. A Minimal Model of Ribosome Allocation Dynamics Captures Trade-offs in Expression between Endogenous and Synthetic Genes.

    PubMed

    Gorochowski, Thomas E; Avcilar-Kucukgoze, Irem; Bovenberg, Roel A L; Roubos, Johannes A; Ignatova, Zoya

    2016-07-15

    Cells contain a finite set of resources that must be distributed across many processes to ensure survival. Among them, the largest proportion of cellular resources is dedicated to protein translation. Synthetic biology often exploits these resources in executing orthogonal genetic circuits, yet the burden this places on the cell is rarely considered. Here, we develop a minimal model of ribosome allocation dynamics capturing the demands on translation when expressing a synthetic construct together with endogenous genes required for the maintenance of cell physiology. Critically, it contains three key variables related to design parameters of the synthetic construct covering transcript abundance, translation initiation rate, and elongation time. We show that model-predicted changes in ribosome allocation closely match experimental shifts in synthetic protein expression rate and cellular growth. Intriguingly, the model is also able to accurately infer transcript levels and translation times after further exposure to additional ambient stress. Our results demonstrate that a simple model of resource allocation faithfully captures the redistribution of protein synthesis resources when faced with the burden of synthetic gene expression and environmental stress. The tractable nature of the model makes it a versatile tool for exploring the guiding principles of efficient heterologous expression and the indirect interactions that can arise between synthetic circuits and their host chassis because of competition for shared translational resources. PMID:27112032

  2. Allocation of environmental loads in recycling: a model based in the qualitative value of recycled material

    NASA Astrophysics Data System (ADS)

    Ferreira, Jose V. R.; Domingos, Idalina; Antunes, Paula

    2001-02-01

    When the life cycle of a product, material or service, studied in a Life Cycle Assessment (LCA) affect other life cycles not included in the system in analysis, it is necessary to apply allocation rules. Allocation can be defined, in LCA context, as the act of assigning the environmental loads of a system to the functions of that system in proportionate shares. Most of the available allocation methods are of generic application, they do not take into account the quality of the materials to be recycled and the few that do take it into account attribute to it a quantitative value. Methods that are both generic and scientifically correct are generally difficult to apply. Rules that are too simple for a case by case application could lead to studies of life cycle assessment that cannot be compared. This way, the best will be to dispose of simple methods but just and mathematically correct with a fundamentally driven application to a sector of economic activity. In this study a method of allocation is proposed which takes into account primarily the "qualitative" value of the material to be recycled, irrespective of being a pos-consumption product/material or a secondary material of a production process. Through a case study, the potential of application of the proposed method is demonstrated, in the recycling of products coming from wood industries and its derivatives, when compared with other allocation methods.

  3. Modelling the climatic drivers determining photosynthesis and carbon allocation in evergreen Mediterranean forests using multiproxy long time series

    NASA Astrophysics Data System (ADS)

    Gea-Izquierdo, G.; Guibal, F.; Joffre, R.; Ourcival, J. M.; Simioni, G.; Guiot, J.

    2015-02-01

    Climatic drivers limit several important physiological processes involved in ecosystem carbon dynamics including gross primary productivity (GPP) and carbon allocation in vegetation. Climatic variability limits these two processes differently. We developed an existing mechanistic model to analyse photosynthesis and variability in carbon allocation in two evergreen species at two Mediterranean forests. The model was calibrated using a combination of eddy covariance CO2 flux data, dendrochronological time series of secondary growth and forest inventory data. The model was modified to be climate explicit in the key processes addressing acclimation of photosynthesis and allocation. It succeeded to fit both the high- and the low-frequency response of stand GPP and carbon allocation to the stem. This would support its capability to address both carbon source and sink limitations. Simulations suggest a decrease in mean stomatal conductance in response to environmental changes and an increase in mean annual intrinsic water use efficiency (iWUE) in both species during the last 50 years. However, this was not translated on a parallel increase in ecosystem water use efficiency (WUE). A long-term decrease in annual GPP matched the local trend in precipitation since the 1970s observed in one site. In contrast, GPP did not show a negative trend and the trees buffered the climatic variability observed at the site where long-term precipitation remained stable. In our simulations these temporal changes would be partly related to increasing [CO2] because the model includes biochemical equations where photosynthesis is directly linked to [CO2]. Long-term trends in GPP did not match those in growth, in agreement with the C-sink hypothesis. There is a great potential to use the model with abundant dendrochronological data and analyse forest performance under climate change. This would help to understand how different interfering environmental factors produce instability in the climatic

  4. Time Utility Functions for Modeling and Evaluating Resource Allocations in a Heterogeneous Computing System

    SciTech Connect

    Briceno, Luis Diego; Khemka, Bhavesh; Siegel, Howard Jay; Maciejewski, Anthony A; Groer, Christopher S; Koenig, Gregory A; Okonski, Gene D; Poole, Stephen W

    2011-01-01

    This study considers a heterogeneous computing system and corresponding workload being investigated by the Extreme Scale Systems Center (ESSC) at Oak Ridge National Laboratory (ORNL). The ESSC is part of a collaborative effort between the Department of Energy (DOE) and the Department of Defense (DoD) to deliver research, tools, software, and technologies that can be integrated, deployed, and used in both DOE and DoD environments. The heterogeneous system and workload described here are representative of a prototypical computing environment being studied as part of this collaboration. Each task can exhibit a time-varying importance or utility to the overall enterprise. In this system, an arriving task has an associated priority and precedence. The priority is used to describe the importance of a task, and precedence is used to describe how soon the task must be executed. These two metrics are combined to create a utility function curve that indicates how valuable it is for the system to complete a task at any given moment. This research focuses on using time-utility functions to generate a metric that can be used to compare the performance of different resource schedulers in a heterogeneous computing system. The contributions of this paper are: (a) a mathematical model of a heterogeneous computing system where tasks arrive dynamically and need to be assigned based on their priority, precedence, utility characteristic class, and task execution type, (b) the use of priority and precedence to generate time-utility functions that describe the value a task has at any given time, (c) the derivation of a metric based on the total utility gained from completing tasks to measure the performance of the computing environment, and (d) a comparison of the performance of resource allocation heuristics in this environment.

  5. Does Distraction Reduce the Alcohol-Aggression Relation?: A Cognitive and Behavioral Test of the Attention-Allocation Model

    PubMed Central

    Gallagher, Kathryn E.; Parrott, Dominic J.

    2011-01-01

    Objective This study provided the first direct test of the cognitive underpinnings of the attention-allocation model and attempted to replicate and extend past behavioral findings for this model as an explanation for alcohol-related aggression. Method A diverse community sample (55% African-American) of males (N = 159) between 21 and 35 years of age (M = 25.80) were randomly assigned to one of two beverage conditions (i.e., alcohol, no-alcohol control) and one of two distraction conditions (i.e., distraction, no-distraction). Following beverage consumption, participants were provoked via reception of electric shocks and a verbal insult from a fictitious male opponent. Participants’ attention-allocation to aggression words (i.e., aggression bias) and physical aggression were measured using a dot probe task and a shock-based aggression task, respectively. Results Intoxicated men whose attention was distracted displayed significantly lower levels of aggression bias and enacted significantly less physical aggression than intoxicated men whose attention was not distracted. However, aggression bias did not account for the lower levels of alcohol-related aggression in the distraction, relative to the no-distraction, condition. Conclusions These results replicated and extended past evidence that cognitive distraction is associated with lower levels of alcohol-related aggression in highly provoked males and provide the first known cognitive data to support the attentional processes posited by the attention-allocation model. Discussion focused on how these data inform intervention programming for alcohol-related aggression. PMID:21500889

  6. Light Competition and Carbon Partitioning-Allocation in an improved Forest Ecosystem Model

    NASA Astrophysics Data System (ADS)

    Collalti, Alessio; Santini, Monia; Valentini Valentini, Riccardo

    2010-05-01

    . Hence, the presence of a cohort in a storey determines the amount of light received for the photosynthetic processes. The population density (numbers of trees per cell) represents a good competition index for determining the tree crown structure and tree crown dimension within a forest population. The tree crown tend to branch out horizontally to intercept as much light as possible. The model assess the structure of the tree crown both vertically and horizontally on the base of the population density and it up-scales the result to the whole stand. The canopy depth and the percentage of horizontal coverage determines moreover a crowding competition index that lead to a specific biomass partitioning-allocation ratio among the different tree components (foliage, roots and stem) and especially for the stem affecting Height-Diameter (at breast height) ratio. In this model, Height-Diameter ratio is used as an alternative competition index in determining the vigour and the strength of competition on free growth status of trees. The forest dominant vegetative cover affects moreover the presence of a dominated layer, it influences its yield and its Carbon stocking capacity and hence it influences the forest ecosystem CO2 carbon balance. From this model it is possible to simulate the impact of Climate Change on forests, the feedback of one or more dominated layers in terms of CO2 uptake in a forest stand and the effects of forest management activities for the next years.

  7. Modelling the climatic drivers determining photosynthesis and carbon allocation in evergreen Mediterranean forests using multiproxy long time series

    NASA Astrophysics Data System (ADS)

    Gea-Izquierdo, G.; Guibal, F.; Joffre, R.; Ourcival, J. M.; Simioni, G.; Guiot, J.

    2015-06-01

    Climatic drivers limit several important physiological processes involved in ecosystem carbon dynamics including gross primary productivity (GPP) and carbon allocation in vegetation. Climatic variability limits these two processes differently. We developed an existing mechanistic model to analyse photosynthesis and variability in carbon allocation in two evergreen species at two Mediterranean forests. The model was calibrated using a combination of eddy covariance CO2 flux data, dendrochronological time series of secondary growth and forest inventory data. The model was modified to be climate explicit in the key processes addressing the acclimation of photosynthesis and the pattern of C allocation, particularly to water stress. It succeeded in fitting both the high- and the low-frequency response of stand GPP and carbon allocation to stem growth. This would support its capability to address both C-source and C-sink limitations. Simulations suggest a decrease in mean stomatal conductance in response to a recent enhancement in water stress and an increase in mean annual intrinsic water use efficiency (iWUE) in both species during the last 50 years. However, this was not translated into a parallel increase in ecosystem water use efficiency (WUE). The interannual variability in WUE closely followed that in iWUE at both sites. Nevertheless, long-term decadal variability in WUE followed the long-term decrease in annual GPP matching the local trend in annual precipitation observed since the late 1970s at one site. In contrast, at the site where long-term precipitation remained stable, GPP and WUE did not show a negative trend and the trees buffered the climatic variability. In our simulations these temporal changes were related to acclimation processes at the canopy level, including modifications in LAI and stomatal conductance, but also partly related to increasing [CO2] because the model includes biochemical equations where photosynthesis is directly linked to [CO2

  8. Sam68 modulates apoptosis of intestinal epithelial cells via mediating NF-κB activation in ulcerative colitis.

    PubMed

    Qian, Ji; Zhao, Weijuan; Miao, Xianjing; Li, Liren; Zhang, Dongmei

    2016-07-01

    Sam68 (Src-associated substrate during mitosis of 68 KDa), also known as KHDRBS1 (KH domain containing, RNA binding, signal transduction associated 1), belongs to the prototypic member of the signal transduction activator of RNA (STAR) family of RNA-binding proteins. Sam68 is implicated in various cellular processes including RNA metabolism, apoptosis, signal transduction. Previous researches demonstrated that Sam68 regulated nuclear transcription factor kappa B (NF-κB) to induce inflammation. However, the expression and biological functions of Sam68 in ulcerative colitis (UC) are not clear. In this study, we reported for the first time that Sam68 was up-regulated in intestinal epithelial cells (IECs) of patients with UC. In DSS-induced mouse colitis model, we observed the overexpression of Sam68 accompanied with increased levels of IEC apoptotic markers (active caspase-3 and cleaved PARP) and NF-κB activation indicators (p-p65 and p-IκB) in colitis IECs. Co-localization of Sam68 with active caspase-3 (and p-p65) in IECs of the DSS-induced colitis group further indicated the possible involvement of NF-κB-mediated IEC apoptosis. Applying TNF-α-treated HT-29 cells as an in vitro IEC inflammation model, we confirmed the positive correlation amomg Sam68, NF-κB activation and caspase-dependent apoptosis. Immunofluorescence and immunoprecipitation assay identified nuclear translocation and physical interaction of Sam68 and NF-κB subunits in TNF-α-treated HT-29 cells. Besides, depletion of Sam68 by RNA interference greatly alleviated NF-κB activation and apoptosis in TNF-α-treated HT-29 cells. Taken together, our results indicated that Sam68 modulates apoptosis of intestinal epithelial cells via mediating NF-κB activation in UC. PMID:27235792

  9. Optimization model for the allocation of water resources based on the maximization of employment in the agriculture and industry sectors

    NASA Astrophysics Data System (ADS)

    Habibi Davijani, M.; Banihabib, M. E.; Nadjafzadeh Anvar, A.; Hashemi, S. R.

    2016-02-01

    In many discussions, work force is mentioned as the most important factor of production. Principally, work force is a factor which can compensate for the physical and material limitations and shortcomings of other factors to a large extent which can help increase the production level. On the other hand, employment is considered as an effective factor in social issues. The goal of the present research is the allocation of water resources so as to maximize the number of jobs created in the industry and agriculture sectors. An objective that has attracted the attention of policy makers involved in water supply and distribution is the maximization of the interests of beneficiaries and consumers in case of certain policies adopted. The present model applies the particle swarm optimization (PSO) algorithm in order to determine the optimum amount of water allocated to each water-demanding sector, area under cultivation, agricultural production, employment in the agriculture sector, industrial production and employment in the industry sector. Based on the results obtained from this research, by optimally allocating water resources in the central desert region of Iran, 1096 jobs can be created in the industry and agriculture sectors, which constitutes an improvement of about 13% relative to the previous situation (non-optimal water utilization). It is also worth mentioning that by optimizing the employment factor as a social parameter, the other areas such as the economic sector are influenced as well. For example, in this investigation, the resulting economic benefits (incomes) have improved from 73 billion Rials at baseline employment figures to 112 billion Rials in the case of optimized employment condition. Therefore, it is necessary to change the inter-sector and intra-sector water allocation models in this region, because this change not only leads to more jobs in this area, but also causes an improvement in the region's economic conditions.

  10. Surface adhesion and confinement variation of Bacillus subtilis on SAM surfaces

    NASA Astrophysics Data System (ADS)

    Swiger, Lauren; Pasquale, Rose; Calabrese, Joseph; Senevirathne, Indrajith

    2012-02-01

    Controlled surface adhesion of non - pathogenic gram positive strain, Bacillus subtilis is interesting as a model system due to possible development of respective biosensors for prevention and detection of the pathogenic variants B. anthracis and B. cereus. Further as a study for bio-machine interfacing systems. Self Assembled Monolayers (SAM) with engineered surfaces of linear thiols on Au(111) were used as the substrate. Sub cultured B. subtilis were used for the analysis. The SAM layered surfaces were dipped in 2 -- 5 Log/ml B. subtilis solution. Subsequent surface adhesion at different bacterial dilutions on surfaces will be discussed, and correlated with quantitative and qualitative adhesion properties of bacteria on the engineered SAM surfaces. The bacteria adhered SAM surfaces were investigated using intermittent contact, noncontact, lateral force and contact modes of Atomic Force Microscopy (AFM).

  11. Surface adhesion and confinement variation of Staphylococcus aurius on SAM surfaces

    NASA Astrophysics Data System (ADS)

    Amroski, Alicia; Olsen, Morgan; Calabrese, Joseph; Senevirathne, Reshani; Senevirathne, Indrajith

    2012-02-01

    Controlled surface adhesion of non - pathogenic gram positive strain, Staphylococcus aureus is interesting as a model system due to possible development of respective biosensors for prevention and detection of the pathogenic strain methicillin resistant Staphylococcus aureus (MRSA) and further as a study for bio-machine interfacing. Self Assembled Monolayers (SAM) with engineered surfaces of linear thiols on Au(111) were used as the substrate. Sub cultured S. aureus were used for the analysis. The SAM layered surfaces were dipped in 2 -- 4 Log/ml S. aureus solution. Subsequent surface adhesion at different bacterial dilutions on surfaces will be discussed, and correlated with quantitative and qualitative adhesion properties of bacteria on the engineered SAM surfaces. The bacteria adhered SAM surfaces were investigated using intermittent contact, noncontact, lateral force and contact modes of Atomic Force Microscopy (AFM).

  12. Introducing health gains in location-allocation models: A stochastic model for planning the delivery of long-term care

    NASA Astrophysics Data System (ADS)

    Cardoso, T.; Oliveira, M. D.; Barbosa-Póvoa, A.; Nickel, S.

    2015-05-01

    Although the maximization of health is a key objective in health care systems, location-allocation literature has not yet considered this dimension. This study proposes a multi-objective stochastic mathematical programming approach to support the planning of a multi-service network of long-term care (LTC), both in terms of services location and capacity planning. This approach is based on a mixed integer linear programming model with two objectives - the maximization of expected health gains and the minimization of expected costs - with satisficing levels in several dimensions of equity - namely, equity of access, equity of utilization, socioeconomic equity and geographical equity - being imposed as constraints. The augmented ε-constraint method is used to explore the trade-off between these conflicting objectives, with uncertainty in the demand and delivery of care being accounted for. The model is applied to analyze the (re)organization of the LTC network currently operating in the Great Lisbon region in Portugal for the 2014-2016 period. Results show that extending the network of LTC is a cost-effective investment.

  13. The ALICE Glance Shift Accounting Management System (SAMS)

    NASA Astrophysics Data System (ADS)

    Martins Silva, H.; Abreu Da Silva, I.; Ronchetti, F.; Telesca, A.; Maidantchik, C.

    2015-12-01

    ALICE (A Large Ion Collider Experiment) is an experiment at the CERN LHC (Large Hadron Collider) studying the physics of strongly interacting matter and the quark-gluon plasma. The experiment operation requires a 24 hours a day and 7 days a week shift crew at the experimental site, composed by the ALICE collaboration members. Shift duties are calculated for each institute according to their correlated members. In order to ensure the full coverage of the experiment operation as well as its good quality, the ALICE Shift Accounting Management System (SAMS) is used to manage the shift bookings as well as the needed training. ALICE SAMS is the result of a joint effort between the Federal University of Rio de Janeiro (UFRJ) and the ALICE Collaboration. The Glance technology, developed by the UFRJ and the ATLAS experiment, sits at the basis of the system as an intermediate layer isolating the particularities of the databases. In this paper, we describe the ALICE SAMS development process and functionalities. The database has been modelled according to the collaboration needs and is fully integrated with the ALICE Collaboration repository to access members information and respectively roles and activities. Run, period and training coordinators can manage their subsystem operation and ensure an efficient personnel management. Members of the ALICE collaboration can book shifts and on-call according to pre-defined rights. ALICE SAMS features a user profile containing all the statistics and user contact information as well as the Institutes profile. Both the user and institute profiles are public (within the scope of the collaboration) and show the credit balance in real time. A shift calendar allows the Run Coordinator to plan data taking periods in terms of which subsystems shifts are enabled or disabled and on-call responsible people and slots. An overview display presents the shift crew present in the control room and allows the Run Coordination team to confirm the presence

  14. Development of integrated model for continuous berth allocation problem and quay crane scheduling with non crossing constraint

    NASA Astrophysics Data System (ADS)

    Basri, Azyanzuhaila Hasan; Zainuddin, Zaitul Marlizawati

    2014-09-01

    High efficiency of port operation is required to succeed in the competition between port container terminals. Berth Allocation and Quay Crane Scheduling are the most important part in container terminal operations. The integrated model is formulated as a MIP problem with the objective to minimize the sum of the dwell times, where a vessel's dwell time is measured between arrival and departure including both times waiting to be berthed and servicing time while berthed. The construction of suitable mathematical model is formulated by considering various practical constraints.

  15. Genetic characterization of senescence-accelerated mouse (SAM).

    PubMed

    Higuchi, K

    1997-01-01

    The Senescence-Accelerated Mouse (SAM) strains are unique and appropriate models for genetic studies on aging because the SAMP strains have an "accelerated senescence" phenotype for which the SAMR strains are controls, and each SAMP strain has a strain-specific age-associated disorder. Furthermore, because they have gone through sufficient generations of sister-brother mating, they can be considered inbred strains, which can be analyzed genetically. There are now 11 SAMP strains and 3 SAMR strains descended from the progenitor litters. Analysis with the Gompertz function shows that the SAMP strains have the same initial mortality rate (IMR) as the SAMR strains but a shorter mortality rate doubling time (MRDT), presumably due to genes that accelerated the rate of senescence in the SAMP strains. This accelerated senescence may also occur in cultured fibroblast-like cells. We performed molecular genetic characterization of all the SAM strains to acquire a base of genetic information from which we could develop hypotheses on the mechanism of development of SAM strains and genetic factors that contribute to accelerated senescence. PMID:9088910

  16. Sam, Brookhaven, and the Physical Review

    NASA Astrophysics Data System (ADS)

    Blume, Martin

    2010-03-01

    Sam Goudsmit came to Brookhaven National Laboratory in 1948, just after the first year of operation of the new institution, and after a year of his postwar appointment as Professor of Physics at Northwestern University. He was named an associate editor of the Physical Review at that time, under the then Managing Editor John T. Tate of the University of Minnesota. Tate had been Editor since 1926, and had presided over the growth of Physical Review to leadership of publication in the world of physics. Tate died in 1950, and after a search under an interim Editor Sam was, in 1951, named Managing Editor. In 1952 he became Chair of the Brookhaven Physics Department, founded Physical Review Letters, and served as department chair until 1960, when he stepped down but remained an Associate Chair. I will discuss my own interactions with Sam during this later period, when I learned of his many faceted talents and accomplishments.

  17. Validation of SAM 2 and SAGE satellite

    NASA Technical Reports Server (NTRS)

    Kent, G. S.; Wang, P.-H.; Farrukh, U. O.; Yue, G. K.

    1987-01-01

    Presented are the results of a validation study of data obtained by the Stratospheric Aerosol and Gas Experiment I (SAGE I) and Stratospheric Aerosol Measurement II (SAM II) satellite experiments. The study includes the entire SAGE I data set (February 1979 - November 1981) and the first four and one-half years of SAM II data (October 1978 - February 1983). These data sets have been validated by their use in the analysis of dynamical, physical and chemical processes in the stratosphere. They have been compared with other existing data sets and the SAGE I and SAM II data sets intercompared where possible. The study has shown the data to be of great value in the study of the climatological behavior of stratospheric aerosols and ozone. Several scientific publications and user-oriented data summaries have appeared as a result of the work carried out under this contract.

  18. Comparison of seven liver allocation models with respect to lives saved among patients on the liver transplant waiting list.

    PubMed

    Magder, Laurence S; Regev, Arie; Mindikoglu, Ayse L

    2012-04-01

    The patients with end-stage liver disease (ESLD) on the liver transplant waiting list are prioritized for transplant based on the model for end-stage liver disease (MELD) score. We developed and used an innovative approach to compare MELD to six proposed alternatives with respect to waiting list mortality. Our analysis was based on United Network for Organ Sharing data of patients with ESLD on the waiting list between January 2006 and June 2009. We compared six allocation models to MELD. Two models were based on reweighting the variables used by MELD: an "updated" MELD, and ReFit MELD. Four models also included serum sodium: MESO, MeldNa, UKELD, and ReFit MELDNa. We estimated that UKELD and the updated MELD would result in significantly fewer lives saved. There were no significant differences between the other models. Our new approach can supplement standard methods to provide insight into the relative performance of liver allocation models in reducing waiting list mortality. Our analysis suggests that UKELD and the updated MELD score would not be optimal for reducing waiting list mortality in the United States. PMID:22299756

  19. Changing model of nursing care from individual patient allocation to team nursing in the acute inpatient environment.

    PubMed

    Fairbrother, Greg; Jones, Aaron; Rivas, Ketty

    2010-06-01

    Agreement was reached with 12 acute medical and surgical wards/units at Sydney's Prince of Wales Hospital to participate in a trial of team nursing (TN). Six units employed action research principles to undertake a change to a team nursing model and six remained with the pre-existing individual patient allocation (IPA) model. Task-based teaming was widely discarded by the team nursing units in favour of allocating patients within the team and introducing more supportive and communicative processes aimed at fostering responsibility sharing. Localised team-based models of care arose in the change wards and were outlined, implemented and refined using social action research principles. A 12-month prospective experimental comparison of job satisfaction and staff retention between the TN and IPA groups indicated statistically significant job satisfaction benefits and practically important staff retention benefits associated with moving away from an IPA model of nursing care delivery towards a team-based model of care delivery. Perhaps not surprisingly, job satisfaction gains were most marked among new graduate nurses, who reported real benefits from a teaming inspired shift in model of care in the acute inpatient environment. PMID:20950201

  20. Refined NMR structure of a heterodimeric SAM:SAM complex. Characterization and manipulation of the EhpA2 interface leads to discovery of new cellular functions of SHIP2

    PubMed Central

    Lee, H. J.; Hota, P. K.; Chugha, P.; Guo, H.; Miao, H.; Zhang, L.; Kim, S. J.; Stetzig, L.

    2012-01-01

    The sterile alpha motif (SAM) for protein-protein interactions is encountered in over 200 proteins, but the structural bases for its interactions is just becoming clear. Here we solved the structure of the EphA2-SHIP2 SAM:SAM heterodimeric complex by use of NMR restraints from chemical shift perturbations, NOE and RDC experiments. Specific contacts between the protein surfaces differ significantly from a previous model and from other SAM:SAM complexes. Molecular dynamics and docking simulations indicate fluctuations in the complex towards alternate, higher energy conformations. The interface suggests that EphA family members bind to SHIP2 SAM whereas EphB members may not; correspondingly we demonstrate binding of EphA1 but not of EphB2 to SHIP2 SAM. A variant of EphB2 SAM was designed that binds SHIP2. Functional characterization of a mutant EphA2 compromised in SHIP2 binding reveals two previously unrecognized functions of SHIP2 in suppressing ligand-induced activation of EphA2 and in promoting chemotactic cell migration in coordination with the receptor. PMID:22244754

  1. Genetic typing of the senescence-accelerated mouse (SAM) strains with microsatellite markers.

    PubMed

    Xia, C; Higuchi, K; Shimizu, M; Matsushita, T; Kogishi, K; Wang, J; Chiba, T; Festing, M F; Hosokawa, M

    1999-03-01

    The Senescence-Accelerated Mouse (SAM) strains constitute a murine model of accelerated senescence originating from the ancestral AKR/J strains and consist of nine senescence-prone (SAMP) strains and four senescence-resistant (SAMR) strains. The chromosomes (Chrs) of the SAM strains were typed with 581 microsatellite markers amplified by PCR, and the fundamental genetic information of the SAM strains was obtained. One-third of the examined markers displayed polymorphism among the strains, and only two alleles were detected in almost all loci among the SAM and AKR/J strains. However, in 12 loci (5.6% of total 215 polymorphic markers), the third allele was detected among the SAM strains. The genetic typing and developmental history suggested that the SAM strains were related inbred strains developed by the accidental crossing between the AKR/J strain and other unknown strain(s). Comparison of the distribution of the loci in the SAMP and the SAMR series revealed notable differences in the four regions on Chrs 4, 14, 16, and 17. This indicated that some of these chromosomal sites might contain the genes responsible for accelerated senescence in the SAMP series. PMID:10051317

  2. Discrimination between closely related cellular metabolites by the SAM-I riboswitch.

    PubMed

    Montange, Rebecca K; Mondragón, Estefanía; van Tyne, Daria; Garst, Andrew D; Ceres, Pablo; Batey, Robert T

    2010-02-26

    The SAM-I riboswitch is a cis-acting element of genetic control found in bacterial mRNAs that specifically binds S-adenosylmethionine (SAM). We previously determined the 2.9-A X-ray crystal structure of the effector-binding domain of this RNA element, revealing details of RNA-ligand recognition. To improve this structure, variations were made to the RNA sequence to alter lattice contacts, resulting in a 0.5-A improvement in crystallographic resolution and allowing for a more accurate refinement of the crystallographic model. The basis for SAM specificity was addressed by a structural analysis of the RNA complexed to S-adenosylhomocysteine (SAH) and sinefungin and by measuring the affinity of SAM and SAH for a series of mutants using isothermal titration calorimetry. These data illustrate the importance of two universally conserved base pairs in the RNA that form electrostatic interactions with the positively charged sulfonium group of SAM, thereby providing a basis for discrimination between SAM and SAH. PMID:20006621

  3. Discrimination between Closely Related Cellular Metabolites by the SAM-I Riboswitch

    SciTech Connect

    Montange, R.; Mondragon, E; van Tyne, D; Garst, A; Ceres, P; Batey, R

    2010-01-01

    The SAM-I riboswitch is a cis-acting element of genetic control found in bacterial mRNAs that specifically binds S-adenosylmethionine (SAM). We previously determined the 2.9-{angstrom} X-ray crystal structure of the effector-binding domain of this RNA element, revealing details of RNA-ligand recognition. To improve this structure, variations were made to the RNA sequence to alter lattice contacts, resulting in a 0.5-{angstrom} improvement in crystallographic resolution and allowing for a more accurate refinement of the crystallographic model. The basis for SAM specificity was addressed by a structural analysis of the RNA complexed to S-adenosylhomocysteine (SAH) and sinefungin and by measuring the affinity of SAM and SAH for a series of mutants using isothermal titration calorimetry. These data illustrate the importance of two universally conserved base pairs in the RNA that form electrostatic interactions with the positively charged sulfonium group of SAM, thereby providing a basis for discrimination between SAM and SAH.

  4. Discrimination between Closely Related Cellular Metabolites by the SAM-I Riboswitch

    PubMed Central

    Montange, Rebecca K.; Mondragón, Estefanía; van Tyne, Daria; Garst, Andrew D.; Ceres, Pablo; Batey, Robert T.

    2009-01-01

    The SAM-I riboswitch is a cis-acting element of genetic control found in bacterial mRNAs that specifically binds S-adenosylmethionine (SAM). We previously determined the 2.9-Å X-ray crystal structure of the effector-binding domain of this RNA element, revealing details of RNA–ligand recognition. To improve this structure, variations were made to the RNA sequence to alter lattice contacts, resulting in a 0.5-Å improvement in crystallographic resolution and allowing for a more accurate refinement of the crystallographic model. The basis for SAM specificity was addressed by a structural analysis of the RNA complexed to S-adenosylhomocysteine (SAH) and sinefungin and by measuring the affinity of SAM and SAH for a series of mutants using isothermal titration calorimetry. These data illustrate the importance of two universally conserved base pairs in the RNA that form electrostatic interactions with the positively charged sulfonium group of SAM, thereby providing a basis for discrimination between SAM and SAH. PMID:20006621

  5. Structural basis for diversity in the SAM clan of riboswitches

    PubMed Central

    Trausch, Jeremiah J.; Xu, Zhenjiang; Edwards, Andrea L.; Reyes, Francis E.; Ross, Phillip E.; Knight, Rob; Batey, Robert T.

    2014-01-01

    In bacteria, sulfur metabolism is regulated in part by seven known families of riboswitches that bind S-adenosyl-l-methionine (SAM). Direct binding of SAM to these mRNA regulatory elements governs a downstream secondary structural switch that communicates with the transcriptional and/or translational expression machinery. The most widely distributed SAM-binding riboswitches belong to the SAM clan, comprising three families that share a common SAM-binding core but differ radically in their peripheral architecture. Although the structure of the SAM-I member of this clan has been extensively studied, how the alternative peripheral architecture of the other families supports the common SAM-binding core remains unknown. We have therefore solved the X-ray structure of a member of the SAM-I/IV family containing the alternative “PK-2” subdomain shared with the SAM-IV family. This structure reveals that this subdomain forms extensive interactions with the helix housing the SAM-binding pocket, including a highly unusual mode of helix packing in which two helices pack in a perpendicular fashion. Biochemical and genetic analysis of this RNA reveals that SAM binding induces many of these interactions, including stabilization of a pseudoknot that is part of the regulatory switch. Despite strong structural similarity between the cores of SAM-I and SAM-I/IV members, a phylogenetic analysis of sequences does not indicate that they derive from a common ancestor. PMID:24753586

  6. Structural Basis for Methyl Transfer by a Radical SAM Enzyme

    SciTech Connect

    Boal, Amie K.; Grove, Tyler L.; McLaughlin, Monica I.; Yennawar, Neela H.; Booker, Squire J.; Rosenzweig, Amy C.

    2014-10-02

    The radical S-adenosyl-l-methionine (SAM) enzymes RlmN and Cfr methylate 23S ribosomal RNA, modifying the C2 or C8 position of adenosine 2503. The methyl groups are installed by a two-step sequence involving initial methylation of a conserved Cys residue (RlmN Cys{sup 355}) by SAM. Methyl transfer to the substrate requires reductive cleavage of a second equivalent of SAM. Crystal structures of RlmN and RlmN with SAM show that a single molecule of SAM coordinates the [4Fe-4S] cluster. Residue Cys{sup 355} is S-methylated and located proximal to the SAM methyl group, suggesting the SAM that is involved in the initial methyl transfer binds at the same site. Thus, RlmN accomplishes its complex reaction with structural economy, harnessing the two most important reactivities of SAM within a single site.

  7. 77 FR 50493 - Sam Rayburn Dam Project Power Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-21

    ... Southwestern Power Administration Sam Rayburn Dam Project Power Rate AGENCY: Southwestern Power Administration, DOE. ACTION: Notice of proposed extension. SUMMARY: The current Sam Rayburn Dam Project rate was... cost recovery criteria. In accordance with Southwestern's isolated project rate adjustment...

  8. Sam's Journey to "Reach for the Stars"

    ERIC Educational Resources Information Center

    Mayer, Sue

    2007-01-01

    In this article, the author shares her experiences as a parent of a child with Down syndrome. Although her son Sam's first years were filled with numerous hospitalizations and visits to pediatricians, which she feared would further delay his development, she soon discovered an organization known as the National Association of Child Development…

  9. 78 FR 62627 - Sam Rayburn Dam Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-22

    ...The U.S. Department of Energy Deputy Secretary has approved and placed into effect on an interim basis Rate Order No. SWPA-67, which increases the power rate for the Sam Rayburn Dam (Rayburn) project pursuant to the Rayburn rate schedule (SRD-13) to supersede the existing rate...

  10. Emerging themes in radical SAM chemistry

    PubMed Central

    Shisler, Krista A; Broderick, Joan B

    2014-01-01

    Enzymes in the radical SAM (RS) superfamily catalyze a wide variety of reactions through unique radical chemistry. The characteristic markers of the superfamily include a [4Fe–4S] cluster coordinated to the protein via a cysteine triad motif, typically CX3CX2C, with the fourth iron coordinated by S-adenosylmethionine (SAM). The SAM serves as a precursor for a 5′-deoxyadenosyl radical, the central intermediate in nearly all RS enzymes studied to date. The SAM-bound [4Fe–4S] cluster is located within a partial or full triosephosphate isomerase (TIM) barrel where the radical chemistry occurs protected from the surroundings. In addition to the TIM barrel and a RS [4Fe–4S] cluster, many members of the superfamily contain additional domains and/or additional Fe–S clusters. Recently characterized superfamily members are providing new examples of the remarkable range of reactions that can be catalyzed, as well as new structural and mechanistic insights into these fascinating reactions. PMID:23141873

  11. Make or buy analysis model based on tolerance allocation to minimize manufacturing cost and fuzzy quality loss

    NASA Astrophysics Data System (ADS)

    Rosyidi, C. N.; Puspitoingrum, W.; Jauhari, W. A.; Suhardi, B.; Hamada, K.

    2016-02-01

    The specification of tolerances has a significant impact on the quality of product and final production cost. The company should carefully pay attention to the component or product tolerance so they can produce a good quality product at the lowest cost. Tolerance allocation has been widely used to solve problem in selecting particular process or supplier. But before merely getting into the selection process, the company must first make a plan to analyse whether the component must be made in house (make), to be purchased from a supplier (buy), or used the combination of both. This paper discusses an optimization model of process and supplier selection in order to minimize the manufacturing costs and the fuzzy quality loss. This model can also be used to determine the allocation of components to the selected processes or suppliers. Tolerance, process capability and production capacity are three important constraints that affect the decision. Fuzzy quality loss function is used in this paper to describe the semantic of the quality, in which the product quality level is divided into several grades. The implementation of the proposed model has been demonstrated by solving a numerical example problem that used a simple assembly product which consists of three components. The metaheuristic approach were implemented to OptQuest software from Oracle Crystal Ball in order to obtain the optimal solution of the numerical example.

  12. EFFECTS OF CYANOPHAGE SAM-1 UPON 'MICROCYSTIS AERUGINOSA'

    EPA Science Inventory

    Cyanophage SAM-1, which infects Synechoccus cedrorum, Anacystis nidulans and certain strains of Microcystis aeruginosa has been isolated from sewage. The host range of cyanophage SAM-1 differs from those of other reported cyanophages. Phage SAM-1 stocks are rapidly inactivated at...

  13. Expanding Radical SAM Chemistry by Using Radical Addition Reactions and SAM Analogues.

    PubMed

    Ji, Xinjian; Li, Yongzhen; Xie, Liqi; Lu, Haojie; Ding, Wei; Zhang, Qi

    2016-09-19

    Radical S-adenosyl-l-methionine (SAM) enzymes utilize a [4Fe-4S] cluster to bind SAM and reductively cleave its carbon-sulfur bond to produce a highly reactive 5'-deoxyadenosyl (dAdo) radical. In almost all cases, the dAdo radical abstracts a hydrogen atom from the substrates or from enzymes, thereby initiating a highly diverse array of reactions. Herein, we report a change of the dAdo radical-based chemistry from hydrogen abstraction to radical addition in the reaction of the radical SAM enzyme NosL. This change was achieved by using a substrate analogue containing an olefin moiety. We also showed that two SAM analogues containing different nucleoside functionalities initiate the radical-based reactions with high efficiencies. The radical adduct with the olefin produced in the reaction was found to undergo two divergent reactions, and the mechanistic insights into this process were investigated in detail. Our study demonstrates a promising strategy in expanding radical SAM chemistry, providing an effective way to access nucleoside-containing compounds by using radical SAM-dependent reactions. PMID:27573794

  14. Optimal control model predictions of system performance and attention allocation and their experimental validation in a display design study

    NASA Technical Reports Server (NTRS)

    Johannsen, G.; Govindaraj, T.

    1980-01-01

    The influence of different types of predictor displays in a longitudinal vertical takeoff and landing (VTOL) hover task is analyzed in a theoretical study. Several cases with differing amounts of predictive and rate information are compared. The optimal control model of the human operator is used to estimate human and system performance in terms of root-mean-square (rms) values and to compute optimized attention allocation. The only part of the model which is varied to predict these data is the observation matrix. Typical cases are selected for a subsequent experimental validation. The rms values as well as eye-movement data are recorded. The results agree favorably with those of the theoretical study in terms of relative differences. Better matching is achieved by revised model input data.

  15. Effects of nonlinear model response on allocation of streamflow depletion: exemplified by the case of Beaver Creek, USA

    NASA Astrophysics Data System (ADS)

    Ahlfeld, David P.; Schneider, James C.; Spalding, Charles P.

    2016-06-01

    Anomalies found when apportioning responsibility for streamflow depletion are examined. The anomalies arise when responsibility is assigned to the two states that contribute to depletion of Beaver Creek in the Republican River Basin in the United States. The apportioning procedure for this basin presumes that the sum of streamflow depletions, computed by comparing simulation model runs with and without groundwater pumping from individual states, approximates the streamflow depletion when both states are pumping. In the case study presented here, this presumed superposition fails dramatically. The stream drying and aquifer-storage depletion, as represented in the simulation model used for allocation, are examined in detail to understand the hydrologic and numerical basis for the severe nonlinear response. Users of apportioning procedures that rely on superposition should be aware of the presence and likely magnitude of nonlinear responses in modeling tools.

  16. Research and evaluation of biomass resources/conversion/utilization systems. Biomass allocation model. Volume 1: Test and appendices A & B

    NASA Astrophysics Data System (ADS)

    Stringer, R. P.; Ahn, Y. K.; Chen, H. T.; Helm, R. W.; Nelson, E. T.; Shields, K. J.

    1981-08-01

    A biomass allocation model was developed to show the most profitable combination of biomass feedstocks, thermochemical conversion processes, and fuel products to serve the seasonal conditions in a regional market. This optimization model provides a tool for quickly calculating which of a large number of potential biomass missions is the most profitable mission. Other components of the system serve as a convenient storage and retrieval mechanism for biomass marketing and thermochemical conversion processing data. The system can be accessed through the use of a computer terminal, or it could be adapted to a microprocessor. A User's Manual for the system is included. Biomass derived fuels included in the data base are the following: medium Btu gas, low Btu gas, substitute natural gas, ammonia, methanol, electricity, gasoline, and fuel oil.

  17. A variation reduction allocation model for quality improvement to minimize investment and quality costs by considering suppliers’ learning curve

    NASA Astrophysics Data System (ADS)

    Rosyidi, C. N.; Jauhari, WA; Suhardi, B.; Hamada, K.

    2016-02-01

    Quality improvement must be performed in a company to maintain its product competitiveness in the market. The goal of such improvement is to increase the customer satisfaction and the profitability of the company. In current practice, a company needs several suppliers to provide the components in assembly process of a final product. Hence quality improvement of the final product must involve the suppliers. In this paper, an optimization model to allocate the variance reduction is developed. Variation reduction is an important term in quality improvement for both manufacturer and suppliers. To improve suppliers’ components quality, the manufacturer must invest an amount of their financial resources in learning process of the suppliers. The objective function of the model is to minimize the total cost consists of investment cost, and quality costs for both internal and external quality costs. The Learning curve will determine how the employee of the suppliers will respond to the learning processes in reducing the variance of the component.

  18. Applying the Attention-Allocation Model to the Explanation of Alcohol-Related Aggression: Implications for Prevention

    PubMed Central

    Giancola, Peter R.; Josephs, Robert A.; DeWall, C. Nathan; Gunn, Rachel L.

    2009-01-01

    The primary purpose of this article is to apply the attention allocation model (AAM; Steele & Josephs, 1990) to the explanation, as well as the prevention, of alcohol-related violence. The AAM contends that alcohol has a “myopic” effect on attentional capacity that presumably facilitates aggression by narrowing attentional focus on the most salient provocative cues, that are naturally present in hostile situations, rather than less salient inhibitory cues. Data are presented to demonstrate support for the AAM with regard to alcohol-related aggression. The model has also been expanded to suggest some intermediary mechanisms that may account for how distracting attention away from provocative cues might be involved in the reduction of aggression. Finally, a number of practical suggestions are put forth regarding how the AAM can be applied to the prevention of intoxicated aggression. PMID:19938917

  19. Hydrogen transfer in SAM-mediated enzymatic radical reactions.

    PubMed

    Hioe, Johnny; Zipse, Hendrik

    2012-12-14

    S-adenosylmethionine (SAM) plays an essential role in a variety of enzyme-mediated radical reactions. One-electron reduction of SAM is currently believed to generate the C5'-desoxyadenosyl radical, which subsequently abstracts a hydrogen atom from the actual substrate in a catalytic or a non-catalytic fashion. Using a combination of theoretical and experimental bond dissociation energy (BDE) data, the energetics of these radical processes have now been quantified. SAM-derived radicals are found to react with their respective substrates in an exothermic fashion in enzymes using SAM in a stoichiometric (non-catalytic) way. In contrast, the catalytic use of SAM appears to be linked to a sequence of moderately endothermic and exothermic reaction steps. The use of SAM in spore photoproduct lyase (SPL) appears to fit neither of these general categories and appears to constitute the first example of a SAM-initiated radical reaction propagated independently of the cofactor. PMID:23139189

  20. Mitochondrial Sorting and Assembly Machinery Subunit Sam37 in Candida albicans: Insight into the Roles of Mitochondria in Fitness, Cell Wall Integrity, and Virulence

    PubMed Central

    Qu, Yue; Jelicic, Branka; Pettolino, Filomena; Perry, Andrew; Lo, Tricia L.; Hewitt, Victoria L.; Bantun, Farkad; Beilharz, Traude H.; Peleg, Anton Y.; Lithgow, Trevor; Djordjevic, Julianne T.

    2012-01-01

    Recent studies indicate that mitochondrial functions impinge on cell wall integrity, drug tolerance, and virulence of human fungal pathogens. However, the mechanistic aspects of these processes are poorly understood. We focused on the mitochondrial outer membrane SAM (Sorting and Assembly Machinery) complex subunit Sam37 in Candida albicans. Inactivation of SAM37 in C. albicans leads to a large reduction in fitness, a phenotype not conserved with the model yeast Saccharomyces cerevisiae. Our data indicate that slow growth of the sam37ΔΔ mutant results from mitochondrial DNA loss, a new function for Sam37 in C. albicans, and from reduced activity of the essential SAM complex subunit Sam35. The sam37ΔΔ mutant was hypersensitive to drugs that target the cell wall and displayed altered cell wall structure, supporting a role for Sam37 in cell wall integrity in C. albicans. The sensitivity of the mutant to membrane-targeting antifungals was not significantly altered. The sam37ΔΔ mutant was avirulent in the mouse model, and bioinformatics showed that the fungal Sam37 proteins are distant from their animal counterparts and could thus represent potential drug targets. Our study provides the first direct evidence for a link between mitochondrial function and cell wall integrity in C. albicans and is further relevant for understanding mitochondrial function in fitness, antifungal drug tolerance, and virulence of this major pathogen. Beyond the relevance to fungal pathogenesis, this work also provides new insight into the mitochondrial and cellular roles of the SAM complex in fungi. PMID:22286093

  1. Water consumption and allocation strategies along the river oases of Tarim River based on large-scale hydrological modelling

    NASA Astrophysics Data System (ADS)

    Yu, Yang; Disse, Markus; Yu, Ruide

    2016-04-01

    With the mainstream of 1,321km and located in an arid area in northwest China, the Tarim River is China's longest inland river. The Tarim basin on the northern edge of the Taklamakan desert is an extremely arid region. In this region, agricultural water consumption and allocation management are crucial to address the conflicts among irrigation water users from upstream to downstream. Since 2011, the German Ministry of Science and Education BMBF established the Sino-German SuMaRiO project, for the sustainable management of river oases along the Tarim River. The project aims to contribute to a sustainable land management which explicitly takes into account ecosystem functions and ecosystem services. SuMaRiO will identify realizable management strategies, considering social, economic and ecological criteria. This will have positive effects for nearly 10 million inhabitants of different ethnic groups. The modelling of water consumption and allocation strategies is a core block in the SuMaRiO cluster. A large-scale hydrological model (MIKE HYDRO Basin) was established for the purpose of sustainable agricultural water management in the main stem Tarim River. MIKE HYDRO Basin is an integrated, multipurpose, map-based decision support tool for river basin analysis, planning and management. It provides detailed simulation results concerning water resources and land use in the catchment areas of the river. Calibration data and future predictions based on large amount of data was acquired. The results of model calibration indicated a close correlation between simulated and observed values. Scenarios with the change on irrigation strategies and land use distributions were investigated. Irrigation scenarios revealed that the available irrigation water has significant and varying effects on the yields of different crops. Irrigation water saving could reach up to 40% in the water-saving irrigation scenario. Land use scenarios illustrated that an increase of farmland area in the

  2. Multi-objective models of waste load allocation toward a sustainable reuse of drainage water in irrigation.

    PubMed

    Allam, Ayman; Tawfik, Ahmed; Yoshimura, Chihiro; Fleifle, Amr

    2016-06-01

    The present study proposes a waste load allocation (WLA) framework for a sustainable quality management of agricultural drainage water (ADW). Two multi-objective models, namely, abatement-performance and abatement-equity-performance, were developed through the integration of a water quality model (QAUL2Kw) and a genetic algorithm, by considering (1) the total waste load abatement, and (2) the inequity among waste dischargers. For successfully accomplishing modeling tasks, we developed a comprehensive overall performance measure (E wla ) reflecting possible violations of Egyptian standards for ADW reuse in irrigation. This methodology was applied to the Gharbia drain in the Nile Delta, Egypt, during both summer and winter seasons of 2012. Abatement-performance modeling results for a target of E wla = 100 % corresponded to the abatement ratio of the dischargers ranging from 20.7 to 75.6 % and 29.5 to 78.5 % in summer and in winter, respectively, alongside highly shifting inequity values. Abatement-equity-performance modeling results for a target of E wla = 90 % unraveled the necessity of increasing treatment efforts in three out of five dischargers during summer, and four out of five in winter. The trade-off curves obtained from WLA models proved their reliability in selecting appropriate WLA procedures as a function of budget constraints, principles of social equity, and desired overall performance level. Hence, the proposed framework of methodologies is of great importance to decision makers working toward a sustainable reuse of the ADW in irrigation. PMID:26951225

  3. The Role of Integrated Modelling and Assessment for Decision-Making: Lessons from Water Allocation Issues in Australia

    NASA Astrophysics Data System (ADS)

    Jakeman, A. J.; Guillaume, J. H. A.; El Sawah, S.; Hamilton, S.

    2014-12-01

    Integrated modelling and assessment (IMA) is best regarded as a process that can support environmental decision-making when issues are strongly contested and uncertainties pervasive. To be most useful, the process must be multi-dimensional and phased. Principally, it must be tailored to the problem context to encompass diverse issues of concern, management settings and stakeholders. This in turn requires the integration of multiple processes and components of natural and human systems and their corresponding spatial and temporal scales. Modellers therefore need to be able to integrate multiple disciplines, methods, models, tools and data, and many sources and types of uncertainty. These dimensions are incorporated into iteration between the various phases of the IMA process, including scoping, problem framing and formulation, assessing options and communicating findings. Two case studies in Australia are employed to share the lessons of how integration can be achieved in these IMA phases using a mix of stakeholder participation processes and modelling tools. One case study aims to improve the relevance of modelling by incorporating stakeholder's views of irrigated viticulture and water management decision making. It used a novel methodology with the acronym ICTAM, consisting of Interviews to elicit mental models, Cognitive maps to represent and analyse individual and group mental models, Time-sequence diagrams to chronologically structure the decision making process, an All-encompassing conceptual model, and computational Models of stakeholder decision making. The second case uses a hydro-economic river network model to examine basin-wide impacts of water allocation cuts and adoption of farm innovations. The knowledge exchange approach used in each case was designed to integrate data and knowledge bearing in mind the contextual dimensions of the problem at hand, and the specific contributions that environmental modelling was thought to be able to make.

  4. Senescence-accelerated mouse (SAM): a biogerontological resource in aging research.

    PubMed

    Takeda, T

    1999-01-01

    The senescence-accelerated mouse (SAM), consisting of 14 senescence-prone inbred strains (SAMP) and 4 senescence-resistant inbred strains (SAMR) has been under development since 1970 through the selective inbreeding of AKR/J strain mice donated by the Jackson laboratory in 1968, based on the data of the grading score of senescence, life span, and pathologic phenotypes. The characteristic feature of aging common to all SAMP and SAMR mice is accelerated senescence and normal aging, respectively. Furthermore, SAMP and SAMR strains manifest various pathobiological phenotypes which include such neurobiological phenotypes as deficits in learning and memory, emotional disorders, abnormal circadian rhythms, brain atrophy, hearing impairment, etc., and are often characteristic enough to differentiate the strains. Various efforts are currently being made using the SAM model to clarify the underlying mechanisms in accelerated senescence as well as the etiopathogenic mechanisms in age-associated pathobiologies. Genetic background and significance of SAM development are discussed. PMID:10537019

  5. AFM-assisted fabrication of thiol SAM pattern with alternating quantified surface potential

    PubMed Central

    2011-01-01

    Thiol self-assembled monolayers (SAMs) are widely used in many nano- and bio-technology applications. We report a new approach to create and characterize a thiol SAMs micropattern with alternating charges on a flat gold-coated substrate using atomic force microscopy (AFM) and Kelvin probe force microscopy (KPFM). We produced SAMs-patterns made of alternating positively charged, negatively charged, and hydrophobic-terminated thiols by an automated AFM-assisted manipulation, or nanografting. We show that these thiol patterns possess only small topographical differences as revealed by AFM, and distinguished differences in surface potential (20-50 mV), revealed by KPFM. The pattern can be helpful in the development of biosensor technologies, specifically for selective binding of biomolecules based on charge and hydrophobicity, and serve as a model for creating surfaces with quantified alternating surface potential distribution. PMID:21711703

  6. Modeling carbon and leaf area allocation in plant canopies via optimization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Modeling the distribution of carbon among leaves in plant canopies is important in order to accurately simulate light interception, growth, and nutrient requirements. However, many explanatory crop models simulate whole organ classes instead of individual organs. For example, many models simulate ...

  7. Competition for light and water increases tree carbon allocation to fine roots and leaves in a next-generation dynamic vegetation model

    NASA Astrophysics Data System (ADS)

    Lichstein, J. W.; Zhang, T.; Weng, E.; Farrior, C.; Dybzinski, R.; Birdsey, R.; Pacala, S. W.

    2015-12-01

    The response of the terrestrial carbon (C) cycle to climate change is a key uncertainty in land models. An important component of this uncertainty concerns plant functional diversity, which is typically represented in land models by ~10 functional types (PFTs) with fixed traits. However, few land models include the individual-level competitive mechanisms that largely determine how plant functional traits are distributed in time and space in real ecosystems. We have developed a new land model that represents height-structured competition for light with a simple canopy space-filling algorithm, the perfect plasticity approximation (PPA). The new land model, LM3-PPA, allows for an arbitrary number of PFTs (or 'species') whose spatial-temporal distributions are determined by the outcome of competition for light and water. We performed experiments with a modified version of LM3-PPA in 10 eastern U.S. grid cells and across simulated precipitation gradients to determine how competition for light and water affects tree C allocation to leaves, fine roots, and wood across climate gradients and in response to episodic drought. We studied the performance of 16 allocational types ('species') in monoculture and in competition with each other to determine the competitively-optimal, NPP-maximizing, and biomass-maximizing C allocation strategy under different environmental conditions. Under chronically moist conditions, competitively-optimal, NPP-maximizing, and biomass-maximizing trees all had similar C allocation. However, under chronically dry conditions, competitively-optimal trees allocated more C to both fine roots and leaves, and less C to wood, compared to NPP- or biomass-maximizing strategies. When subject to episodic drought, the most drought-tolerant allocational strategies had relatively low allocation to leaves (and thus low leaf area and low water demand). Thus, the "over-investment" in leaves that results from resource competition increases the vulnerability of

  8. Obituary: Sam Roweis (1972-2010)

    NASA Astrophysics Data System (ADS)

    Hogg, David

    2011-12-01

    Computer scientist and statistical astronomer Sam Roweis took his own life in New York City on 2010 January 12. He was a brilliant and accomplished researcher in the field of machine learning, and a strong advocate for the use of computational statistics for automating discovery and scientific data analysis. He made several important contributions to astronomy and was working on adaptive astronomical data analysis at the time of his death. Roweis obtained his PhD in 1999 from the California Institute of Technology, where he worked on a remarkable range of subjects, including DNA computing, modeling of dynamical systems, signal processing, and speech recognition. During this time he unified and clarified some of the most important data analysis techniques, including Principal Component Analysis, Hidden Markov Models, and Expectation Maximization. His work was aimed at making data analysis and modeling faster, but also better justified scientifically. The last years of his PhD were spent in Princeton NJ, where he came in contact with a young generation of cosmologists thinking about microwave background and large-scale structure data. In a postdoc at University College London, Roweis co-created the Locally Linear Embedding (LLE) algorithm; a simple but flexible technique for mapping a large data set onto a low-dimensional manifold. The LLE paper obtained more than 2700 citations in 9 years, launched a new sub-field of machine learning known as "manifold learning," and inspired work in data visualization, search, and applied mathematics. In 2001, Roweis took a faculty job at the University of Toronto Computer Science Department. He continued working on data analysis methods that have probabilistic interpretation and therefore scientific applicability, but at the same time have good performance on large data sets. He was awarded a Sloan Fellowship, a Canada Research Chair, and a fellowship of the Canadian Institute for Advanced Research, among other honors and awards

  9. Comparison of three methods for the optimal allocation of hydrological model participation in an Ensemble Prediction System

    NASA Astrophysics Data System (ADS)

    Brochero, D.; Anctil, F.; Gagné, C.

    2012-04-01

    Today, the availability of the Meteorological Ensemble Prediction Systems (MEPS) and its subsequent coupling with multiple hydrological models offer the possibility of building Hydrological Ensemble Prediction Systems (HEPS) consisting of a large number of members. However, this task is complex both in terms of the coupling of information and of the computational time, which may create an operational barrier. The evaluation of the prominence of each hydrological members can be seen as a non-parametric post-processing stage that seeks finding the optimal participation of the hydrological models (in a fashion similar to the Bayesian model averaging technique), maintaining or improving the quality of a probabilistic forecasts based on only x members drawn from a super ensemble of d members, thus allowing the reduction of the task required to issue the probabilistic forecast. The main objective of the current work consists in assessing the degree of simplification (reduction of the number of hydrological members) that can be achieved with a HEPS configured using 16 lumped hydrological models driven by the 50 weather ensemble forecasts from the European Centre for Medium-range Weather Forecasts (ECMWF), i.e. an 800-member HEPS. In a previous work (Brochero et al., 2011a, b), we demonstrated that the proportion of members allocated to each hydrological model is a sufficient criterion to reduce the number of hydrological members while improving the balance of the scores, taking into account interchangeability of the ECMWF MEPS. Here, we compare the proportion of members allocated to each hydrological model derived from three non-parametric techniques: correlation analysis of hydrological members, Backward Greedy Selection (BGS) and Nondominated Sorting Genetic Algorithm (NSGA II). The last two techniques allude to techniques developed in machine learning, in a multicriteria framework exploiting the relationship between bias, reliability, and the number of members of the

  10. Statistical analysis of blocking probability and fragmentation based on Markov modeling of elastic spectrum allocation on fiber link

    NASA Astrophysics Data System (ADS)

    Rosa, A. N. F.; Wiatr, P.; Cavdar, C.; Carvalho, S. V.; Costa, J. C. W. A.; Wosinska, L.

    2015-11-01

    In Elastic Optical Network (EON), spectrum fragmentation refers to the existence of non-aligned, small-sized blocks of free subcarrier slots in the optical spectrum. Several metrics have been proposed in order to quantify a level of spectrum fragmentation. Approximation methods might be used for estimating average blocking probability and some fragmentation measures, but are so far unable to accurately evaluate the influence of different sizes of connection requests and do not allow in-depth investigation of blocking events and their relation to fragmentation. The analytical study of the effect of fragmentation on requests' blocking probability is still under-explored. In this work, we introduce new definitions for blocking that differentiate between the reasons for the blocking events. We developed a framework based on Markov modeling to calculate steady-state probabilities for the different blocking events and to analyze fragmentation related problems in elastic optical links under dynamic traffic conditions. This framework can also be used for evaluation of different definitions of fragmentation in terms of their relation to the blocking probability. We investigate how different allocation request sizes contribute to fragmentation and blocking probability. Moreover, we show to which extend blocking events, due to insufficient amount of available resources, become inevitable and, compared to the amount of blocking events due to fragmented spectrum, we draw conclusions on the possible gains one can achieve by system defragmentation. We also show how efficient spectrum allocation policies really are in reducing the part of fragmentation that in particular leads to actual blocking events. Simulation experiments are carried out showing good match with our analytical results for blocking probability in a small scale scenario. Simulated blocking probabilities for the different blocking events are provided for a larger scale elastic optical link.

  11. MMW, IR, and SAM signature collection

    NASA Astrophysics Data System (ADS)

    Reichstetter, Fred; Ward, Mary E.

    2002-08-01

    During the development of smart weapon's seeker/sensors, it is imperative to collect high quality signatures of the targets the system is intended to engage. These signatures are used to support algorithm development so the system can find and engage the targets of interest in the specific kill area on the target. Englin AFB FL is the AF development center for munitions; and in support of the development effort, the 46th Test Wing (46 TW) has initiated significant improvements in collection capabilities for signatures in the MMW, Infrared and Seismic, Acoustic and Magnetic (SAM) spectrum. Additionally, the Joint Munitions Test and Evaluation program office maintains a fleet of foreign ground vehicle targets used for such signature collection including items such as tanks, SCUD missile launchers, air defense units such as SA-06, SA-8, SA-13, and associated ground support trucks and general purpose vehicles. The major test facility includes a 300 ft tower used for mounting the instrumentation suite that currently includes, 10, 35 and 94 GHz MMW and 2-5(mu) and 8-12(mu) IR instrumentation systems. This facility has undergone major improvements in terms of background signature reduction, construction of a high bay building to house the turntable on which the targets are mounted, and an additional in- ground stationary turntable primarily for IR signature collection. Our experience using this facility to collect signatures for the smart weapons development community has confirmed a significant improvement in quality and efficiency. The need for the stationary turntable signature collection capability was driven by the requirements of the IR community who are interested in collecting signatures in clutter. This tends to be contrary to the MMW community that desires minimum background clutter. The resulting location, adjacent to the MMW tower, allows variations in the type and amount of clutter background that could be incorporated and also provides maximum utilization of

  12. A sub-canopy structure for simulating oil palm in the Community Land Model: phenology, allocation and yield

    NASA Astrophysics Data System (ADS)

    Fan, Y.; Roupsard, O.; Bernoux, M.; Le Maire, G.; Panferov, O.; Kotowska, M. M.; Knohl, A.

    2015-06-01

    Land surface modelling has been widely used to characterize the two-way interactions between climate and human activities in terrestrial ecosystems such as deforestation, agricultural expansion, and urbanization. Towards an effort to quantify the effects of forests to oil palm conversion occurring in the tropics on land-atmosphere carbon, water and energy fluxes, we introduce a new perennial crop plant functional type (PFT) for oil palm. Due to the modular and sequential nature of oil palm growth (around 40 stacked phytomers) and yield (fruit bunches axillated on each phytomer), we developed a specific sub-canopy structure for simulating palm's growth and yield within the framework of the Community Land Model (CLM4.5). In this structure each phytomer has its own prognostic leaf growth and fruit yield capacity like a PFT but with shared stem and root components among all phytomers. Phenology and carbon and nitrogen allocation operate on the different phytomers in parallel but at unsynchronized steps, so that multiple fruit yields per annum are enabled in terms of carbon and nitrogen outputs. An important phenological phase is identified for the palm PFT - the storage growth period of bud and "spear" leaves which are photosynthetically inactive before expansion. Agricultural practices such as transplanting, fertilization, and leaf pruning are represented. Parameters introduced for the new PFT were calibrated and validated with field measurements of leaf area index (LAI) and yield from Sumatra, Indonesia. In calibration with a mature oil palm plantation, the cumulative yields from 2005 to 2014 matched perfectly between simulation and observation (mean percentage error = 4 %). Simulated inter-annual dynamics of PFT-level and phytomer-level LAI were both within the range of field measurements. Validation from eight independent oil palm sites shows the ability of the model to adequately predict the average leaf growth and fruit yield across sites but also indicates that

  13. A Fuzzy Robust Optimization Model for Waste Allocation Planning Under Uncertainty

    PubMed Central

    Xu, Ye; Huang, Guohe; Xu, Ling

    2014-01-01

    Abstract In this study, a fuzzy robust optimization (FRO) model was developed for supporting municipal solid waste management under uncertainty. The Development Zone of the City of Dalian, China, was used as a study case for demonstration. Comparing with traditional fuzzy models, the FRO model made improvement by considering the minimization of the weighted summation among the expected objective values, the differences between two extreme possible objective values, and the penalty of the constraints violation as the objective function, instead of relying purely on the minimization of expected value. Such an improvement leads to enhanced system reliability and the model becomes especially useful when multiple types of uncertainties and complexities are involved in the management system. Through a case study, the applicability of the FRO model was successfully demonstrated. Solutions under three future planning scenarios were provided by the FRO model, including (1) priority on economic development, (2) priority on environmental protection, and (3) balanced consideration for both. The balanced scenario solution was recommended for decision makers, since it respected both system economy and reliability. The model proved valuable in providing a comprehensive profile about the studied system and helping decision makers gain an in-depth insight into system complexity and select cost-effective management strategies. PMID:25317037

  14. District Allocation of Human Resources Utilizing the Evidence Based Model: A Study of One High Achieving School District in Southern California

    ERIC Educational Resources Information Center

    Lane, Amber Marie

    2013-01-01

    This study applies the Gap Analysis Framework to understand the gaps that exist in human resource allocation of one Southern California school district. Once identified, gaps are closed with the reallocation of human resources, according to the Evidenced Based Model, requiring the re-purposing of core classroom teachers, specialists, special…

  15. An Innovative Time-Cost-Quality Tradeoff Modeling of Building Construction Project Based on Resource Allocation

    PubMed Central

    2014-01-01

    The time, quality, and cost are three important but contradictive objectives in a building construction project. It is a tough challenge for project managers to optimize them since they are different parameters. This paper presents a time-cost-quality optimization model that enables managers to optimize multiobjectives. The model is from the project breakdown structure method where task resources in a construction project are divided into a series of activities and further into construction labors, materials, equipment, and administration. The resources utilized in a construction activity would eventually determine its construction time, cost, and quality, and a complex time-cost-quality trade-off model is finally generated based on correlations between construction activities. A genetic algorithm tool is applied in the model to solve the comprehensive nonlinear time-cost-quality problems. Building of a three-storey house is an example to illustrate the implementation of the model, demonstrate its advantages in optimizing trade-off of construction time, cost, and quality, and help make a winning decision in construction practices. The computational time-cost-quality curves in visual graphics from the case study prove traditional cost-time assumptions reasonable and also prove this time-cost-quality trade-off model sophisticated. PMID:24672351

  16. Halomethane production in plants: Structure of the biosynthetic SAM-dependent halide methyltransferase from Arabidopsis thaliana**

    PubMed Central

    Schmidberger, Jason W.; James, Agata B.; Edwards, Robert; Naismith, James H.; O’Hagan, David

    2012-01-01

    A product structure of the halomethane producing enzyme in plants (Arabidopsis thaliana) is reported and a model for presentation of chloride/bromide ion to the methyl group of S-adenosyl-L-methionine (SAM) is presented to rationalise nucleophilic halide attack for halomethane production, gaseous natural products that are produced globally. PMID:20376845

  17. A Minimalistic Resource Allocation Model to Explain Ubiquitous Increase in Protein Expression with Growth Rate

    PubMed Central

    Keren, Leeat; Segal, Eran; Milo, Ron

    2016-01-01

    Most proteins show changes in level across growth conditions. Many of these changes seem to be coordinated with the specific growth rate rather than the growth environment or the protein function. Although cellular growth rates, gene expression levels and gene regulation have been at the center of biological research for decades, there are only a few models giving a base line prediction of the dependence of the proteome fraction occupied by a gene with the specific growth rate. We present a simple model that predicts a widely coordinated increase in the fraction of many proteins out of the proteome, proportionally with the growth rate. The model reveals how passive redistribution of resources, due to active regulation of only a few proteins, can have proteome wide effects that are quantitatively predictable. Our model provides a potential explanation for why and how such a coordinated response of a large fraction of the proteome to the specific growth rate arises under different environmental conditions. The simplicity of our model can also be useful by serving as a baseline null hypothesis in the search for active regulation. We exemplify the usage of the model by analyzing the relationship between growth rate and proteome composition for the model microorganism E.coli as reflected in recent proteomics data sets spanning various growth conditions. We find that the fraction out of the proteome of a large number of proteins, and from different cellular processes, increases proportionally with the growth rate. Notably, ribosomal proteins, which have been previously reported to increase in fraction with growth rate, are only a small part of this group of proteins. We suggest that, although the fractions of many proteins change with the growth rate, such changes may be partially driven by a global effect, not necessarily requiring specific cellular control mechanisms. PMID:27073913

  18. A Minimalistic Resource Allocation Model to Explain Ubiquitous Increase in Protein Expression with Growth Rate.

    PubMed

    Barenholz, Uri; Keren, Leeat; Segal, Eran; Milo, Ron

    2016-01-01

    Most proteins show changes in level across growth conditions. Many of these changes seem to be coordinated with the specific growth rate rather than the growth environment or the protein function. Although cellular growth rates, gene expression levels and gene regulation have been at the center of biological research for decades, there are only a few models giving a base line prediction of the dependence of the proteome fraction occupied by a gene with the specific growth rate. We present a simple model that predicts a widely coordinated increase in the fraction of many proteins out of the proteome, proportionally with the growth rate. The model reveals how passive redistribution of resources, due to active regulation of only a few proteins, can have proteome wide effects that are quantitatively predictable. Our model provides a potential explanation for why and how such a coordinated response of a large fraction of the proteome to the specific growth rate arises under different environmental conditions. The simplicity of our model can also be useful by serving as a baseline null hypothesis in the search for active regulation. We exemplify the usage of the model by analyzing the relationship between growth rate and proteome composition for the model microorganism E.coli as reflected in recent proteomics data sets spanning various growth conditions. We find that the fraction out of the proteome of a large number of proteins, and from different cellular processes, increases proportionally with the growth rate. Notably, ribosomal proteins, which have been previously reported to increase in fraction with growth rate, are only a small part of this group of proteins. We suggest that, although the fractions of many proteins change with the growth rate, such changes may be partially driven by a global effect, not necessarily requiring specific cellular control mechanisms. PMID:27073913

  19. Public Data at CeSAM

    NASA Astrophysics Data System (ADS)

    Moreau, C.; Le Brun, V.; Agneray, F.; Gimenez, S.; Roehlly, Y.

    2014-05-01

    Modern large observational programs produce important amounts of data from various origins, and need high level data-quality control, fast data access via easy-to-use graphic interfaces, as well as possibility to cross-correlate informations coming from different observations. The Centre de donneS Astrophysique de Marseille (CeSAM) has for mission to provide support to the teams in charge of the observational programs (specifications, software development and infrastructures), to produce and give the final data by proposing tools increasing their scientific value. We present here the various datasets hosted by the CeSAM under the ANIS environment. Even if mainly oriented towards large spectro-photometric extragalactic samples, we host as well an exoplanet transit database, or resolved galaxy data. The main datasets are those from the VVDS final release (45000 spectra), the Herschel extragalactic surveys (HerMES, HRS, GOODS-Herschel, VNGS), the CFHTLS-WIDE photometric redshifts catalog (17 millions objects), or the HST-COSMOS information system, that allows request from any of the 6 and access to the corresponding values in the other catalogs.

  20. A coupled agronomic-economic model to consider allocation of brackish irrigation water

    NASA Astrophysics Data System (ADS)

    Ben-Gal, Alon; Weikard, Hans-Peter; Shah, Syed Hamid Hussain; Zee, Sjoerd E. A. T. M.

    2013-05-01

    In arid and semiarid regions, irrigation water is scarce and often contains high concentrations of salts. To reduce negative effects on crop yields, the irrigated amounts must include water for leaching and therefore exceed evapotranspiration. The leachate (drainage) water returns to water sources such as rivers or groundwater aquifers and increases their level of salinity and the leaching requirement for irrigation water of any sequential user. We develop a conceptual sequential (upstream-downstream) model of irrigation that predicts crop yields and water consumption and tracks the water flow and level of salinity along a river dependent on irrigation management decisions. The model incorporates an agro-physical model of plant response to environmental conditions including feedbacks. For a system with limited water resources, the model examines the impacts of water scarcity, salinity and technically inefficient application on yields for specific crop, soil, and climate conditions. Moving beyond the formulation of a conceptual frame, we apply the model to the irrigation of Capsicum annum on Arava Sandy Loam soil. We show for this case how water application could be distributed between upstream and downstream plots or farms. We identify those situations where it is beneficial to trade water from upstream to downstream farms (assuming that the upstream farm holds the water rights). We find that water trade will improve efficiency except when loss levels are low. We compute the marginal value of water, i.e., the price water would command on a market, for different levels of water scarcity, salinity and levels of water loss.

  1. Evaluation of a digital model for estuarine water quality simulation in waste allocation studies

    USGS Publications Warehouse

    Seaburn, G.E.; Jennings, Marshall E.; Merritt, Michael L.

    1979-01-01

    Hydrologic and water-quality data were collected on 4 estuaries in Pasco, Citrus, and Pinellas Counties, Florida, to evaluate modeling results. Current and predicted waste loading of the four estuaries was simulated by use of a two-dimensional steady-state, intertidal-condition model. Concentrations of DO, carbonaceous and nitrogenous BOD, and chloride were simulated as averages over a tidal cycle. General equations for the model are based on the law of conservation of mass. Assumption of steady-state required that water-quality data for calibration be averaged over an appropriate time cycle with respect to volume and cross-section. Diurnal DO fluctuation was determined in 2 estuaries for evaluating the influence of photosynthesis and respiration. The estuary model is best applied by calibrating it for a particular set of observed conditions, and then using this calibrated model for sensitivity analyses without attempting to verify the chosen parameter values against a second set of conditions. Sensitivity analyses included dispersion coefficient , decay rates, photosynthesis, and respiration. (Woodard-USGS)

  2. Multiple polymer architectures of human Polyhomeotic homolog 3 (PHC3) SAM

    PubMed Central

    Nanyes, David R.; Junco, Sarah E.; Taylor, Alexander B.; Robinson, Angela K.; Patterson, Nicolle L.; Shivarajpur, Ambika; Halloran, Jonathan; Hale, Seth M.; Kaur, Yogeet; Hart, P. John; Kim, Chongwoo A.

    2014-01-01

    The self-association of sterile alpha motifs (SAMs) into a helical polymer architecture is a critical functional component of many different and diverse array of proteins. For the Drosophila Polycomb group (PcG) protein Polyhomeotic (Ph), its SAM polymerization serves as the structural foundation to cluster multiple PcG complexes, helping to maintain a silenced chromatin state. Ph SAM shares 64% sequence identity with its human ortholog, PHC3 SAM, and both SAMs polymerize. However, in the context of their larger protein regions, PHC3 SAM forms longer polymers compared to Ph SAM. Motivated to establish the precise structural basis for the differences, if any, between Ph and PHC3 SAM, we determined the crystal structure of the PHC3 SAM polymer. PHC3 SAM utilizes the same SAM-SAM interaction as the Ph SAM six-fold repeat polymer. Yet, PHC3 SAM polymerizes utilizing just five SAMs per turn of the helical polymer rather than the typical six per turn observed for all SAM polymers reported to date. Structural analysis suggested that malleability of the PHC3 SAM would allow formation of not just the five-fold repeat structure but possibly others. Indeed, a second PHC3 SAM polymer in a different crystal form forms a six-fold repeat polymer. These results suggest that the polymers formed by PHC3 SAM, and likely others, are quite dynamic. The functional consequence of the variable PHC3 SAM polymers may be to create different chromatin architectures. PMID:25044168

  3. Fruiting Strategies of Perennial Plants: A Resource Budget Model to Couple Mast Seeding to Pollination Efficiency and Resource Allocation Strategies.

    PubMed

    Venner, Samuel; Siberchicot, Aurélie; Pélisson, Pierre-François; Schermer, Eliane; Bel-Venner, Marie-Claude; Nicolas, Manuel; Débias, François; Miele, Vincent; Sauzet, Sandrine; Boulanger, Vincent; Delzon, Sylvain

    2016-07-01

    Masting, a breeding strategy common in perennial plants, is defined by seed production that is highly variable over years and synchronized at the population level. Resource budget models (RBMs) proposed that masting relies on two processes: (i) the depletion of plant reserves following high fruiting levels, which leads to marked temporal fluctuations in fruiting; and (ii) outcross pollination that synchronizes seed crops among neighboring trees. We revisited the RBM approach to examine the extent to which masting could be impacted by the degree of pollination efficiency, by taking into account various logistic relationships between pollination success and pollen availability. To link masting to other reproductive traits, we split the reserve depletion coefficient into three biological parameters related to resource allocation strategies for flowering and fruiting. While outcross pollination is considered to be the key mechanism that synchronizes fruiting in RBMs, our model counterintuitively showed that intense masting should arise under low-efficiency pollination. When pollination is very efficient, medium-level masting may occur, provided that the costs of female flowering (relative to pollen production) and of fruiting (maximum fruit set and fruit size) are both very high. Our work highlights the powerful framework of RBMs, which include explicit biological parameters, to link fruiting dynamics to various reproductive traits and to provide new insights into the reproductive strategies of perennial plants. PMID:27322122

  4. Energy and resource allocation: a dynamic model of the Dutch disease. [Monograph

    SciTech Connect

    Bruno, M.; Sachs, J.

    1982-01-01

    It is well known that a domestic-response discovery gives rise to wealth effects that cause a squeeze of the tradeable-good sector of an open economy. The decline of the manufacturing sector following an energy discovery has been termed the Dutch disease, and has been investigated in many recent studies. The authors' model extends the principally static analyses to date by allowing for: (1) short-run capital specificity and long-run capital mobility; (2) international capital flows; and (3) far-sighted intertemporal optimzing behavior by households and firms. The model is solved by numerical simulation. 9 references, 4 figures, 6 tables.

  5. Influence of vegetation dynamic modeling on the allocation of green and blue waters

    NASA Astrophysics Data System (ADS)

    Ruiz-Pérez, Guiomar; Francés, Félix

    2015-04-01

    The long history of the Mediterranean region is dominated by the interactions and co-evolution between man and its natural environment. It is important to consider that the Mediterranean region is recurrently or permanently confronted with the scarcity of the water. The issue of climate change is (and will be) aggravating this situation. This raises the question of a loss of services that ecosystems provide to human and also the amount of available water to be used by vegetation. The question of the water cycle, therefore, should be considered in an integrated manner by taking into account both blue water (water in liquid form used for the human needs or which flows into the oceans) and green water (water having the vapor for resulting from evaporation and transpiration processes). In spite of this, traditionally, very few hydrological models have incorporated the vegetation dynamic as a state variable. In fact, most of them are able to represent fairly well the observed discharge, but usually including the vegetation as a static parameter. However, in the last decade, the number of hydrological models which explicitly take into account the vegetation development as a state variable has increased substantially. In this work, we want to analyze if it is really necessary to use a dynamic vegetation model to quantify adequately the distribution of water into blue and green water. The study site is located in the Public Forest Monte de la Hunde y Palomeras (Spain). The vegetation in the study area is dominated by Aleppo pine of high tree density with scant presence of other species. Two different daily models were applied (with static and dynamic vegetation representation respectively) in three different scenarios: dry year (2005), normal year (2008) and wet year (2010). The static vegetation model simulates the evapotranspiration considering the vegetation as a stationary parameter. Contrarily, the dynamic vegetation model connects the hydrological model with a

  6. CARBON AND NITROGEN ALLOCATION MODEL FOR THE SEAGRASS THALASSIA TESTUDUNUM IN LOWER LAGUNA MADRE

    EPA Science Inventory

    Inverse modeling methods are a powerful tool for understanding complex physiological relationships between seagrasses and their environment. The power of the method is a result of using ranges of data in a system of constraints to describe the biological system, in this case, t...

  7. Towards Decentralized and Goal-Oriented Models of Institutional Resource Allocation: The Spanish Case

    ERIC Educational Resources Information Center

    Lopez, Maria Jose Gonzalez

    2006-01-01

    The search for more flexibility in financial management of public universities demands adjustments in budgeting strategies. International studies on this topic recommend wider financial autonomy for management units, the use of budgeting models based on performance, the implementation of formula systems for the determination of financial needs of…

  8. Block models for improved earthwork allocation planning in linear infrastructure construction

    NASA Astrophysics Data System (ADS)

    Burdett, R.; Kozan, E.; Kenley, R.

    2015-03-01

    Earthwork planning is considered in this article and a generic block partitioning and modelling approach is devised to provide strategic plans of various levels of detail. Conceptually, this new approach is more accurate and comprehensive than others, for instance those that are section based. In response to recent environmental concerns, the metric for decision making was fuel consumption or emissions. Haulage distance and gradient, however, are important components of these metrics and are also included. Advantageously, the fuel consumption metric is generic and captures the physical difficulties of travelling over inclines of different gradients, which is consistent across all hauling vehicles. For validation, the proposed models and techniques are applied to a real-world road project. The numerical investigations demonstrate that the models can be solved with relatively little CPU time. The proposed block models also result in solutions of superior quality, i.e. they have reduced fuel consumption and cost. Furthermore, the plans differ considerably from those based solely on a distance-based metric, thus demonstrating a need for the industry to reflect on its current practices.

  9. Inhibition of Sam68 triggers adipose tissue browning.

    PubMed

    Zhou, Junlan; Cheng, Min; Boriboun, Chan; Ardehali, Mariam M; Jiang, Changfei; Liu, Qinghua; Han, Shuling; Goukassian, David A; Tang, Yao-Liang; Zhao, Ting C; Zhao, Ming; Cai, Lu; Richard, Stéphane; Kishore, Raj; Qin, Gangjian

    2015-06-01

    Obesity is associated with insulin resistance and type 2 diabetes; molecular mechanisms that promote energy expenditure can be utilized for effective therapy. Src-associated in mitosis of 68 kDa (Sam68) is potentially significant, because knockout (KO) of Sam68 leads to markedly reduced adiposity. In the present study, we sought to determine the mechanism by which Sam68 regulates adiposity and energy homeostasis. We first found that Sam68 KO mice have a significantly reduced body weight as compared to controls, and the difference is explained entirely by decreased adiposity. Interestingly, these effects were not mediated by a difference in food intake; rather, they were associated with enhanced physical activity. When they were fed a high-fat diet, Sam68 KO mice gained much less body weight and fat mass than their WT littermates did, and they displayed an improved glucose and insulin tolerance. In Sam68 KO mice, the brown adipose tissue (BAT), inguinal, and epididymal depots were smaller, and their adipocytes were less hypertrophied as compared to their WT littermates. The BAT of Sam68 KO mice exhibited reduced lipid stores and expressed higher levels of Ucp1 and key thermogenic and fatty acid oxidation genes. Similarly, depots of inguinal and epididymal white adipose tissue (WAT) in Sam68 KO mice appeared browner, their multilocular Ucp1-positive cells were much more abundant, and the expression of Ucp1, Cidea, Prdm16, and Ppargc1a genes was greater as compared to WT controls, which suggests that the loss of Sam68 also promotes WAT browning. Furthermore, in all of the fat depots of the Sam68 KO mice, the expression of M2 macrophage markers was up-regulated, and that of M1 markers was down-regulated. Thus, Sam68 plays a crucial role in controlling thermogenesis and may be targeted to combat obesity and associated disorders. PMID:25934704

  10. Inhibition of Sam68 triggers adipose tissue browning

    PubMed Central

    Zhou, Junlan; Cheng, Min; Boriboun, Chan; Ardehali, Mariam Mina; Jiang, Changfei; Liu, Qinghua; Han, Shuling; Goukassian, David A.; Tang, Yao-Liang; Zhao, Ting C.; Zhao, Ming; Cai, Lu; Richard, Stéphane; Kishore, Raj; Qin, Gangjian

    2015-01-01

    Obesity is associated with insulin resistance and type 2 diabetes; molecular mechanisms promoting energy expenditure may be utilized for effective therapy. Src-associated-in-mitosis-of-68kDa (Sam68) is potentially significant because knockout (KO) of Sam68 leads to markedly-reduced adiposity. Here we sought to determine the mechanism by which Sam68 regulates adiposity and energy homeostasis. We firstly found in Sam68-KO mice a significantly-reduced body weight with the difference explained entirely by decreased adiposity. Interestingly, these effects were not mediated by a difference in food intake, but rather associated with enhanced physical activity. When fed high-fat diet, Sam68-KO mice gained much lesser body weight and fat mass as compared to wild-type (WT) littermates and displayed an improved glucose and insulin tolerance. The brown adipose tissue (BAT), inguinal and epididymal depots are smaller and their adipocytes less hypertrophy in Sam68-KO mice than in WT littermates. The BAT of Sam68-KO mice exhibited reduced lipid stores and expressed higher levels of Ucp1 and key thermogenic and fatty-acid-oxidation genes. Similarly, depots of inguinal and epididymal white adipose tissue (WAT) in Sam68-KO mice appeared browner, their multilocular Ucp1-positive cells were much more abundant, and the expression of Ucp1, Cidea, Prdm16 and Ppargc1a genes was greater as compared to WT controls, suggesting that loss of Sam68 also promotes WAT browning. Furthermore, in all fat depots of Sam68-KO mice, the expression of M2 macrophage markers were upregulated and M1 markers downregulated. Thus Sam68 plays a crucial role in the control of thermogenesis and may be targeted to combat obesity and associated disorders. PMID:25934704

  11. Agent based model of effects of task allocation strategies in flat organizations

    NASA Astrophysics Data System (ADS)

    Sobkowicz, Pawel

    2016-09-01

    A common practice in many organizations is to pile the work on the best performers. It is easy to implement by the management and, despite the apparent injustice, appears to be working in many situations. In our work we present a simple agent based model, constructed to simulate this practice and to analyze conditions under which the overall efficiency of the organization (for example measured by the backlog of unresolved issues) breaks down, due to the cumulative effect of the individual overloads. The model confirms that the strategy mentioned above is, indeed, rational: it leads to better global results than an alternative one, using equal workload distribution among all workers. The presented analyses focus on the behavior of the organizations close to the limit of the maximum total throughput and provide results for the growth of the unprocessed backlog in several situations, as well as suggestions related to avoiding such buildup.

  12. Modeling the Dynamics of Task Allocation and Specialization in Honeybee Societies

    NASA Astrophysics Data System (ADS)

    Hoogendoorn, Mark; Schut, Martijn C.; Treur, Jan

    The concept of organization has been studied in sciences such as social science and economics, but recently also in artificial intelligence [Furtado 2005, Giorgini 2004, and McCallum 2005]. With the desire to analyze and design more complex systems consisting of larger numbers of agents (e.g., in nature, society, or software), the need arises for a concept of higher abstraction than the concept agent. To this end, organizational modeling is becoming a practiced stage in the analysis and design of multi-agent systems, hereby taking into consideration the environment of the organization. An environment can have a high degree of variability which might require organizations to adapt to the environment's dynamics, to ensure a continuous proper functioning of the organization. Hence, such change processes are a crucial function of the organization and should be part of the organizational model.

  13. A Numerical model to evaluate proposed ground-water allocations in southwest Kansas

    USGS Publications Warehouse

    Jorgensen, D.G.; Grubb, H.F.; Baker, C.H.; Hilmes, G.E.; Jenkins, E.D.

    1982-01-01

    A computer model was developed to assist the Southwest Kansas Groundwater Management District No. 3 in the evaluation of applications to appropriate ground water. The model calculated the drawdown due from a proposed well at all existing wells in the section of the proposed well and at all wells in the adjacent eight sections. The depletion expected in the 9-square-mile area due to all existing wells and the proposed well is computed and compared with allowable limits defined by the management district. An optional program permits the evaluation of allowable depletion for one or more townships. All options are designed to run interactively, thus allowing for immediate evaluation of proposed ground-water withdrawals. (USGS)

  14. Microeconomics-based resource allocation in overlay networks by using non-strategic behavior modeling

    NASA Astrophysics Data System (ADS)

    Analoui, Morteza; Rezvani, Mohammad Hossein

    2011-01-01

    Behavior modeling has recently been investigated for designing self-organizing mechanisms in the context of communication networks in order to exploit the natural selfishness of the users with the goal of maximizing the overall utility. In strategic behavior modeling, the users of the network are assumed to be game players who seek to maximize their utility with taking into account the decisions that the other players might make. The essential difference between the aforementioned researches and this work is that it incorporates the non-strategic decisions in order to design the mechanism for the overlay network. In this solution concept, the decisions that a peer might make does not affect the actions of the other peers at all. The theory of consumer-firm developed in microeconomics is a model of the non-strategic behavior that we have adopted in our research. Based on it, we have presented distributed algorithms for peers' "joining" and "leaving" operations. We have modeled the overlay network as a competitive economy in which the content provided by an origin server can be viewed as commodity and the origin server and the peers who multicast the content to their downside are considered as the firms. On the other hand, due to the dual role of the peers in the overlay network, they can be considered as the consumers as well. On joining to the overlay economy, each peer is provided with an income and tries to get hold of the service regardless to the behavior of the other peers. We have designed the scalable algorithms in such a way that the existence of equilibrium price (known as Walrasian equilibrium price) is guaranteed.

  15. ALAWAT: A spatially allocated watershed model for approximating stream, sediment, and pollutant flows in Hawaii, USA

    NASA Astrophysics Data System (ADS)

    Freeman, William; Fox, Jefferson

    1995-07-01

    The Ala Wai Canal Watershed Model (ALAWAT) is a planning-level watershed model for approximating direct runoff, streamflow, sediment loads, and loads for up to five pollutants. ALAWAT uses raster GIS data layers including land use, SCS soil hydrologic groups, annual rainfall, and subwatershed delineations as direct model parameter inputs and can use daily total rainfall from up to ten rain gauges and streamflow from up to ten stream gauges. ALAWAT uses a daily time step and can simulate flows for up to ten-year periods and for up to 50 subwatersheds. Pollutant loads are approximated using a user-defined combination of rating curve relationships, mean event concentrations, and loading/washoff parameters for specific subwatersheds, land uses, and times of year. Using ALAWAT, annual average streamflow and baseflow relationships and urban suspended sediment loads were approximated for the Ala Wai Canal watershed (about 10,400 acres) on the island of Oahu, Hawaii. Annual average urban suspended sediments were approximated using two methods: mean event concentrations and pollutant loading and washoff. Parameters for the pollutant loading and washoff method were then modified to simulate the effect of various street sweeping intervals on sediment loads.

  16. C allocation among fine roots, above-, and belowground wood in a deciduous forest and its implication to ecosystem C cycling: a modelling analysis

    NASA Astrophysics Data System (ADS)

    Campioli, M.; Verbeeck, H.; Lemeur, R.; Samson, R.

    2008-09-01

    Knowledge about allocation of carbohydrates among tree organs with different life times and decomposition rates is crucial in determining the residence time of carbon (C) in forests and the overall ecosystem C cycling rate. A new model (named CAF) able to simulate C allocation among fine roots, above-, and belowground wood in deciduous forests was developed and integrated into the net ecosystem exchange model FORUG. CAF draws on growth rules and source-sink relationships. Maintenance and growth of the modelled sinks i.e. fine roots, coarse roots, stems, and branches, are controlled by phenology, environment, and by the reserve of non-structural carbohydrates. CAF was parameterized for 2-y and tested against 6-y observations from a beech (Fagus sylvatica L.) stand in North-East France, experiencing summer droughts of different intensities. The model reproduced well (i) the C fluxes allocated annually to assimilation, respiration and biomass production, and (ii) the interannual pattern of wood biomass accumulation. Seasonality of C reserve and wood growth was captured, but some discrepancies were detected at the onset of the growing season. The allocation pattern differed among years, although the overall net primary production decreased only in case of severe drought. During a year with severe drought, the fraction of C allocated to production of fast-decomposing C pools (e.g. fine roots, C reserve) increased by +13% than years without drought, whereas the same fraction increased on average by +18% in case of low to moderate drought. Carbon invested in biomass during a year with summer drought has therefore a shorter residence time in the ecosystem than the C stored during a year without summer drought.

  17. Mathematical modelling of diurnal regulation of carbohydrate allocation by osmo-related processes in plants.

    PubMed

    Pokhilko, Alexandra; Ebenhöh, Oliver

    2015-03-01

    Plants synthesize sucrose in source tissues (mainly mature leafs) and supply it for growth of sink tissues (young leafs). Sucrose is derived from photosynthesis during daytime and from starch at night. Because the diurnal regulation of sucrose fluxes is not completely understood, we built a mathematical model designed to reproduce all key experimental observations. For this, assumptions were made about the molecular mechanisms underlying the regulations, which are all motivated by experimental facts. The key regulators in our model are two kinases (SnRK1 and osmo-sensitive kinase OsmK) under the control of the circadian clock. SnRK1 is activated in the night to prepare for regularly occurring carbon-limiting conditions, whereas OsmK is activated during the day to prepare for water deficit, which often occurs in the afternoon. Decrease of SnRK1 and increase of OsmK result in partitioning of carbon towards sucrose to supply growing sink tissues. Concomitantly, increasing levels of the growth regulator trehalose-6-phosphate stimulates the development of new sink tissues and thus sink demand, which further activates sucrose supply in a positive feedback loop. We propose that OsmK acts as a timer to measure the length of the photoperiod and suggest experiments how this hypothesis can be validated. PMID:25631572

  18. Using SAM Assessment and Training for Office 2003

    ERIC Educational Resources Information Center

    Whittle, Gary

    2005-01-01

    This presentation will demonstrate the uses of SAM 2003 from Course Technology as a skills assessment and training software that is used via the Internet. Historically, testing in computer education has taken the form of pencil and paper or standardized testing. The actual computer skills of the student have not been properly assessed. With SAM,…

  19. Increased forest carbon storage with increased atmospheric CO2 despite nitrogen limitation: a game-theoretic allocation model for trees in competition for nitrogen and light.

    PubMed

    Dybzinski, Ray; Farrior, Caroline E; Pacala, Stephen W

    2015-03-01

    Changes in resource availability often cause competitively driven changes in tree allocation to foliage, wood, and fine roots, either via plastic changes within individuals or through turnover of individuals with differing strategies. Here, we investigate how optimally competitive tree allocation should change in response to elevated atmospheric CO2 along a gradient of nitrogen and light availability, together with how those changes should affect carbon storage in living biomass. We present a physiologically-based forest model that includes the primary functions of wood and nitrogen. From a tree's perspective, wood is an offensive and defensive weapon used against neighbors in competition for light. From a biogeochemical perspective, wood is the primary living reservoir of stored carbon. Nitrogen constitutes a tree's photosynthetic machinery and the support systems for that machinery, and its limited availability thus reduces a tree's ability to fix carbon. This model has been previously successful in predicting allocation to foliage, wood, and fine roots along natural productivity gradients. Using game theory, we solve the model for competitively optimal foliage, wood, and fine root allocation strategies for trees in competition for nitrogen and light as a function of CO2 and nitrogen mineralization rate. Instead of down-regulating under nitrogen limitation, carbon storage under elevated CO2 relative to carbon storage at ambient CO2 is approximately independent of the nitrogen mineralization rate. This surprising prediction is a consequence of both increased competition for nitrogen driving increased fine root biomass and increased competition for light driving increased allocation to wood under elevated CO2 . PMID:25392967

  20. [Anti-aging studies on the senescence accelerated mouse (SAM) strains].

    PubMed

    Takahashi, Ryoya

    2010-01-01

    Senescence accelerated mouse (SAM), a murine model of accelerated senescence, was established by Toshio Takeda and colleagues. SAM consists of series of SAMP (prone) and SAMR (resistant) lines. All SAMP lines (from SAMP1 to SAMP11) are characterized by accelerated accumulation of senile features, earlier onset and faster progress of age-associated pathological phenotypes, such as amyloidosis, impaired immune response, senile osteoporosis and deficits in learning and memory. These SAMP lines are useful for evaluation of putative anti-aging therapies. For example, SAMP1 line is used to study the anti-aging effect of the antioxidant containing foods and various anti-oxidants, such as coenzyme Q10, vitamin C, lycopene. SAMP8 line exhibiting an early onset of impaired learning and memory is often used for test strategies for therapeutic intervention of dementia of early onset. SAMP6 is used as an animal model for developing new strategies for the treatment of osteoporosis in humans. Various lines of SAM (P1, P6, P8, P10 and R1) are now commercially available for research. In this review, I will briefly introduce various usages of SAM in anti-aging research. PMID:20046059

  1. Methodologies for optimal resource allocation to the national space program and new space utilizations. Volume 2: Resource allocation and smoothing model, programmer's manual

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Appendixes are presented that provide model input requirements, a sample case, flow charts, and a program listing. At the beginning of each appendix, descriptive details and technical comments are provided to indicate any special instructions applicable to the use of that appendix. In addition, the program listing includes comment cards that state the purpose of each subroutine in the complete program and describe operations performed within that subroutine. The input requirements includes details on the many options that adapt the program to the specific needs of the analyst for a particular problem.

  2. Obituary: Sam Roweis (1972-2010)

    NASA Astrophysics Data System (ADS)

    Hogg, David

    2011-12-01

    Computer scientist and statistical astronomer Sam Roweis took his own life in New York City on 2010 January 12. He was a brilliant and accomplished researcher in the field of machine learning, and a strong advocate for the use of computational statistics for automating discovery and scientific data analysis. He made several important contributions to astronomy and was working on adaptive astronomical data analysis at the time of his death. Roweis obtained his PhD in 1999 from the California Institute of Technology, where he worked on a remarkable range of subjects, including DNA computing, modeling of dynamical systems, signal processing, and speech recognition. During this time he unified and clarified some of the most important data analysis techniques, including Principal Component Analysis, Hidden Markov Models, and Expectation Maximization. His work was aimed at making data analysis and modeling faster, but also better justified scientifically. The last years of his PhD were spent in Princeton NJ, where he came in contact with a young generation of cosmologists thinking about microwave background and large-scale structure data. In a postdoc at University College London, Roweis co-created the Locally Linear Embedding (LLE) algorithm; a simple but flexible technique for mapping a large data set onto a low-dimensional manifold. The LLE paper obtained more than 2700 citations in 9 years, launched a new sub-field of machine learning known as "manifold learning," and inspired work in data visualization, search, and applied mathematics. In 2001, Roweis took a faculty job at the University of Toronto Computer Science Department. He continued working on data analysis methods that have probabilistic interpretation and therefore scientific applicability, but at the same time have good performance on large data sets. He was awarded a Sloan Fellowship, a Canada Research Chair, and a fellowship of the Canadian Institute for Advanced Research, among other honors and awards

  3. Economic Analysis Case Studies of Battery Energy Storage with SAM

    SciTech Connect

    DiOrio, Nicholas; Dobos, Aron; Janzou, Steven

    2015-11-01

    Interest in energy storage has continued to increase as states like California have introduced mandates and subsidies to spur adoption. This energy storage includes customer sited behind-the-meter storage coupled with photovoltaics (PV). This paper presents case study results from California and Tennessee, which were performed to assess the economic benefit of customer-installed systems. Different dispatch strategies, including manual scheduling and automated peak-shaving were explored to determine ideal ways to use the storage system to increase the system value and mitigate demand charges. Incentives, complex electric tariffs, and site specific load and PV data were used to perform detailed analysis. The analysis was performed using the free, publically available System Advisor Model (SAM) tool. We find that installation of photovoltaics with a lithium-ion battery system priced at $300/kWh in Los Angeles under a high demand charge utility rate structure and dispatched using perfect day-ahead forecasting yields a positive net-present value, while all other scenarios cost the customer more than the savings accrued. Different dispatch strategies, including manual scheduling and automated peak-shaving were explored to determine ideal ways to use the storage system to increase the system value and mitigate demand charges. Incentives, complex electric tariffs, and site specific load and PV data were used to perform detailed analysis. The analysis was performed using the free, publically available System Advisor Model (SAM) tool. We find that installation of photovoltaics with a lithium-ion battery system priced at $300/kWh in Los Angeles under a high demand charge utility rate structure and dispatched using perfect day-ahead forecasting yields a positive net-present value, while all other scenarios cost the customer more than the savings accrued.

  4. Simulating smoke transport from wildland fires with a regional-scale air quality model: sensitivity to spatiotemporal allocation of fire emissions.

    PubMed

    Garcia-Menendez, Fernando; Hu, Yongtao; Odman, Mehmet T

    2014-09-15

    Air quality forecasts generated with chemical transport models can provide valuable information about the potential impacts of fires on pollutant levels. However, significant uncertainties are associated with fire-related emission estimates as well as their distribution on gridded modeling domains. In this study, we explore the sensitivity of fine particulate matter concentrations predicted by a regional-scale air quality model to the spatial and temporal allocation of fire emissions. The assessment was completed by simulating a fire-related smoke episode in which air quality throughout the Atlanta metropolitan area was affected on February 28, 2007. Sensitivity analyses were carried out to evaluate the significance of emission distribution among the model's vertical layers, along the horizontal plane, and into hourly inputs. Predicted PM2.5 concentrations were highly sensitive to emission injection altitude relative to planetary boundary layer height. Simulations were also responsive to the horizontal allocation of fire emissions and their distribution into single or multiple grid cells. Additionally, modeled concentrations were greatly sensitive to the temporal distribution of fire-related emissions. The analyses demonstrate that, in addition to adequate estimates of emitted mass, successfully modeling the impacts of fires on air quality depends on an accurate spatiotemporal allocation of emissions. PMID:24973934

  5. The dynamic of annual carbon allocation to wood in European forests is consistent with a combined source-sink limitation of growth: implications for modelling

    NASA Astrophysics Data System (ADS)

    Guillemot, J.; Martin-StPaul, N. K.; Dufrêne, E.; François, C.; Soudani, K.; Ourcival, J. M.; Delpierre, N.

    2015-02-01

    The extent to which forest growth is limited by carbon (C) supply (source control) or by cambial activity (sink control) will condition the response of trees to global changes. However, the physiological processes responsible for the limitation of forest growth are still under debate. The aim of this study is to evaluate the key drivers of the annual carbon allocation to wood along large soil and climate regional gradients in five tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex, Quercus robur and Picea abies). Combining field measurements and process-based simulations at 49 sites (931 site-years), we assessed the stand biomass growth dependences at both inter-site and inter-annual scales. Specifically, the relative influence of forest C balance (source control), direct environmental control (water and temperature controls of sink activity) and allocation adjustments related to age, past climate conditions, competition intensity and soil nutrient availability on growth were quantified. The inter-site variability in stand C allocation to wood was predominantly driven by an age-related decline. The direct control of temperature or water stress on sink activity (i.e. independently from their effects on C supply) exerted a strong influence on the annual stand woody growth in all the species considered, including deciduous temperate species. The lagged effect of the past environment conditions was a significant driver of the annual C allocation to wood. Carbon supply appeared to strongly limit growth only in deciduous temperate species. We provide an evaluation of the spatio-temporal dynamics of annual carbon allocation to wood in European forests. Our study supports the premise that European forest growth is under a complex control including both source and sink limitations. The relative influences of the different growth drivers strongly vary across years and spatial ecological gradients. We suggest a

  6. Comparing Surfaces and Engineered Interfaces using Self-Assembled Monolayers (SAMs) and Injected SAMs Silanes

    SciTech Connect

    Morris, Mark J.; Simmons, Kevin L.

    2003-11-01

    The objective of this study was to show a comparison between property changes by formation of a self-assembled monolayer on the surface of PPG synthetic precipitated silica, which is a technique developed at PNNL, and by adding the SAMs silane chemical directly into the mixing bowl. These coatings have the potential to greatly increase the bond strength and enhance other properties between the particle and the rubber matrix of a rubber compound. Tensile testing measured peak stress and elongation at break. The increase in tensile strength shows how well the polymer-filler interfacial adhesion is doing. The study used five different SAM systems with a sulfur cured styrene butadiene rubber (SBR) tire rubber formulation. The three propylsilanes were propyl triethoxysilane, allyl triethoxysilane and 3-mercaptopropyl triethoxysilane. Five combinations of silanes were used in this study. The application of the silanes were 100% propyl triethoxy silane (100% Alkyl); a 10/90 mixture of allyl and propyl triethoxy silanes (10% vinyl/90% alkyl); a 50/50 mixture of the allyl and propyl (50% vinyl/50% alkyl); a 10/90mixture of 3-mercaptopropyl trimethoxysilane and propyl trimethoxysilane (10% mercaptan/90% alkyl) and lastly a 50/50 3-mercaptopropyl and propylsilanes (50% mercaptan/alkyl). The data not only shows improvement with SAMs, the peak stress data (ultimate strength) shows that the by changing the amount of silane content can change the physical properties

  7. Scenario-Based Multi-Objective Optimum Allocation Model for Earthquake Emergency Shelters Using a Modified Particle Swarm Optimization Algorithm: A Case Study in Chaoyang District, Beijing, China

    PubMed Central

    Zhao, Xiujuan; Xu, Wei; Ma, Yunjia; Hu, Fuyu

    2015-01-01

    The correct location of earthquake emergency shelters and their allocation to residents can effectively reduce the number of casualties by providing safe havens and efficient evacuation routes during the chaotic period of the unfolding disaster. However, diverse and strict constraints and the discrete feasible domain of the required models make the problem of shelter location and allocation more difficult. A number of models have been developed to solve this problem, but there are still large differences between the models and the actual situation because the characteristics of the evacuees and the construction costs of the shelters have been excessively simplified. We report here the development of a multi-objective model for the allocation of residents to earthquake shelters by considering these factors using the Chaoyang district, Beijing, China as a case study. The two objectives of this model were to minimize the total weighted evacuation time from residential areas to a specified shelter and to minimize the total area of all the shelters. The two constraints were the shelter capacity and the service radius. Three scenarios were considered to estimate the number of people who would need to be evacuated. The particle swarm optimization algorithm was first modified by applying the von Neumann structure in former loops and global structure in later loops, and then used to solve this problem. The results show that increasing the shelter area can result in a large decrease in the total weighted evacuation time from scheme 1 to scheme 9 in scenario A, from scheme 1 to scheme 9 in scenario B, from scheme 1 to scheme 19 in scenario C. If the funding were not a limitation, then the final schemes of each scenario are the best solutions, otherwise the earlier schemes are more reasonable. The modified model proved to be useful for the optimization of shelter allocation, and the result can be used as a scientific reference for planning shelters in the Chaoyang district

  8. SAM68 is a physiological regulator of SMN2 splicing in spinal muscular atrophy

    PubMed Central

    Pagliarini, Vittoria; Pelosi, Laura; Bustamante, Maria Blaire; Nobili, Annalisa; Berardinelli, Maria Grazia; D’Amelio, Marcello; Musarò, Antonio

    2015-01-01

    Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by loss of motor neurons in patients with null mutations in the SMN1 gene. The almost identical SMN2 gene is unable to compensate for this deficiency because of the skipping of exon 7 during pre–messenger RNA (mRNA) processing. Although several splicing factors can modulate SMN2 splicing in vitro, the physiological regulators of this disease-causing event are unknown. We found that knockout of the splicing factor SAM68 partially rescued body weight and viability of SMAΔ7 mice. Ablation of SAM68 function promoted SMN2 splicing and expression in SMAΔ7 mice, correlating with amelioration of SMA-related defects in motor neurons and skeletal muscles. Mechanistically, SAM68 binds to SMN2 pre-mRNA, favoring recruitment of the splicing repressor hnRNP A1 and interfering with that of U2AF65 at the 3′ splice site of exon 7. These findings identify SAM68 as the first physiological regulator of SMN2 splicing in an SMA mouse model. PMID:26438828

  9. Observed allocations of productivity and biomass, and turnover times in tropical forests are not accurately represented in CMIP5 Earth system models

    NASA Astrophysics Data System (ADS)

    Negrón-Juárez, Robinson I.; Koven, Charles D.; Riley, William J.; Knox, Ryan G.; Chambers, Jeffrey Q.

    2015-06-01

    A significant fraction of anthropogenic CO2 emissions is assimilated by tropical forests and stored as biomass, slowing the accumulation of CO2 in the atmosphere. Because different plant tissues have different functional roles and turnover times, predictions of carbon balance of tropical forests depend on how earth system models (ESMs) represent the dynamic allocation of productivity to different tree compartments. This study shows that observed allocation of productivity, biomass, and turnover times of main tree compartments (leaves, wood, and roots) are not accurately represented in Coupled Model Intercomparison Project Phase 5 ESMs. In particular, observations indicate that biomass saturates with increasing productivity. In contrast, most models predict continuous increases in biomass with increases in productivity. This bias may lead to an over-prediction of carbon uptake in response to CO2 or climate-driven changes in productivity. Compartment-specific productivity and biomass are useful benchmarks to assess terrestrial ecosystem model performance. Improvements in the predicted allocation patterns and turnover times by ESMs will reduce uncertainties in climate predictions.

  10. SAM Gcms Chromatography Performed at Mars : Elements of Interpretation

    NASA Astrophysics Data System (ADS)

    Szopa, C.; Coll, P. J.; Buch, A.; François, P.; Cabane, M.; Coscia, D.; Teinturier, S.; Navarro-Gonzalez, R.; Glavin, D. P.; Freissinet, C.; Mahaffy, P. R.

    2013-12-01

    The characterisation of the chemical and mineralogical composition of regolith samples collected with the Curiosity rover is a primary objective of the SAM experiment. These data should provide essential clues on the past habitability of Gale crater. Interpretation of the data collected after SAM pyrolysis evolved gas analysis (EGA) and gas chromatography mass spectrometry (GC-MS) experiments on the first soil samples collected by MSL at the Rocknest Aeolian Deposit in Gale Crater has been challenging due to the concomitant presence in the ovens of an oxychlorine phase present in the samples, and a derivatization agent coming from the SAM wet chemistry experiment (Glavin et al., 2013). Moreover, accurate identification and quantification, in the SAM EGA mode, of volatiles released from the heated sample, or generated by reactions occurring in the SAM pyrolysis oven, is also difficult for a few compounds due to evolution over similar temperature ranges and overlap of their MS signatures. Hence, the GC analyses, coupled with MS, enabled the separation and identification and quantification of most of the volatile compounds detected. These results can have been obtained through tests and calibration done with GC individual spare components and with the SAM testbed. This paper will present a view of the interpretation of the chromatograms obtained when analyzing the Rocknest and John Klein solid samples delivered to SAM, on sols 96 and 199 respectively, supported by laboratory calibrations.

  11. Beta test results for the CAA mini-SAM system

    SciTech Connect

    Johnson, R.C.; Monagle, M.

    1997-04-01

    The mission of the Chemical Analysis Automation (CAA) Program is to automate methods for chemical analysis of environmental samples. To accomplish this mission, the CAA team has developed automated laboratory systems based on a plug-and-work strategy for integrating components. Realizing that standardization is the key to implementing this strategy, CAA has developed, demonstrated, and encouraged commercialization of standards for laboratory automation. While the CAA mission is driven by the analyses in support of the extensive remediation programs of the Departments of Energy and Defense, it also impacts any industry that depends upon high volumes of repetitive chemical analysis. A Standard Analysis Method (SAM) is any collection of hardware and software used to automate part or all of a method. The method automated for the Mini-SAM testing is EPA Method 3550, which outlines semivolatiles extraction by sonication. The list of semivolatiles includes the polychlorinated biphenyl (PCB) analytes of interest. The basic building block of a SAM is the Standard Laboratory Module (SLM). For the Mini-SAM test an automated sonication SLM and an automated concentration SLM were configured to perform the extraction and concentration processes. The Mini-SAM differs from the Full-SAM in that a fully automated delivery of materials, samples, and extracts is not required. The intent of the Beta Test of the Mini-SAM was threefold. Firstly, the Mini-SAM Beta Test met a milestone mandated by the Department of Energy in the course of the program effort. Secondly, the CAA Program secured an independent assessment of the equipment and its capabilities from Assagai Analytical Laboratory. Lastly, the Program captured real-world sample data. The independent assessment, coupled with CAA observation of equipment performance, was used to determine strengths and weaknesses of the Mini-SAM and to compile possible modifications for CAA engineers to address.

  12. SAM 2 and SAGE data management and processing

    NASA Technical Reports Server (NTRS)

    Osborn, M. T.; Trepte, C. R.

    1987-01-01

    The data management and processing supplied by ST Systems Corporation (STX) for the Stratospheric Aerosol Measurement 2 (SAM 2) and Stratospheric Aerosol and Gas Experiment (SAGE) experiments for the years 1983 to 1986 are described. Included are discussions of data validation, documentation, and scientific analysis, as well as the archival schedule met by the operational reduction of SAM 2 and SAGE data. Work under this contract resulted in the archiving of the first seven years of SAM 2 data and all three years of SAGE data. A list of publications and presentations supported was also included.

  13. Recent Advances in Radical SAM Enzymology: New Structures and Mechanisms

    PubMed Central

    2015-01-01

    The radical S-adenosylmethionine (SAM) superfamily of enzymes catalyzes an amazingly diverse variety of reactions ranging from simple hydrogen abstraction to complicated multistep rearrangements and insertions. The reactions they catalyze are important for a broad range of biological functions, including cofactor and natural product biosynthesis, DNA repair, and tRNA modification. Generally conserved features of the radical SAM superfamily include a CX3CX2C motif that binds an [Fe4S4] cluster essential for the reductive cleavage of SAM. Here, we review recent advances in our understanding of the structure and mechanisms of these enzymes that, in some cases, have overturned widely accepted mechanisms. PMID:25009947

  14. A Multistep, Consensus-Based Approach to Organ Allocation in Liver Transplantation: Toward a "Blended Principle Model".

    PubMed

    Cillo, U; Burra, P; Mazzaferro, V; Belli, L; Pinna, A D; Spada, M; Nanni Costa, A; Toniutto, P

    2015-10-01

    Since Italian liver allocation policy was last revised (in 2012), relevant critical issues and conceptual advances have emerged, calling for significant improvements. We report the results of a national consensus conference process, promoted by the Italian College of Liver Transplant Surgeons (for the Italian Society for Organ Transplantation) and the Italian Association for the Study of the Liver, to review the best indicators for orienting organ allocation policies based on principles of urgency, utility, and transplant benefit in the light of current scientific evidence. MELD exceptions and hepatocellular carcinoma were analyzed to construct a transplantation priority algorithm, given the inequity of a purely MELD-based system for governing organ allocation. Working groups of transplant surgeons and hepatologists prepared a list of statements for each topic, scoring their quality of evidence and strength of recommendation using the Centers for Disease Control grading system. A jury of Italian transplant surgeons, hepatologists, intensivists, infectious disease specialists, epidemiologists, representatives of patients' associations and organ-sharing organizations, transplant coordinators, and ethicists voted on and validated the proposed statements. After carefully reviewing the statements, a critical proposal for revising Italy's current liver allocation policy was prepared jointly by transplant surgeons and hepatologists. PMID:26274338

  15. Modeling seed weight under environmental resource limitations as a function of C, N, and C:N allocation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The carbon (C) and nitrogen (N) contents and C:N ratio in seed of two genotypes each of five crops with different resource allocation patterns were assessed under normal growing degree days (GDD) and normal population density (NN) for each crop; normal GDD and 25%>normal population density (NL); sho...

  16. Crystal structures of the SAM-III/S[subscript MK] riboswitch reveal the SAM-dependent translation inhibition mechanism

    SciTech Connect

    Lu, C.; Smith, A.M.; Fuchs, R.T.; Ding, F.; Rajashankar, K.; Henkin, T.M.; Ke, A.

    2010-01-07

    Three distinct classes of S-adenosyl-L-methionine (SAM)-responsive riboswitches have been identified that regulate bacterial gene expression at the levels of transcription attenuation or translation inhibition. The SMK box (SAM-III) translational riboswitch has been identified in the SAM synthetase gene in members of the Lactobacillales. Here we report the 2.2-{angstrom} crystal structure of the Enterococcus faecalis SMK box riboswitch. The Y-shaped riboswitch organizes its conserved nucleotides around a three-way junction for SAM recognition. The Shine-Dalgarno sequence, which is sequestered by base-pairing with the anti-Shine-Dalgarno sequence in response to SAM binding, also directly participates in SAM recognition. The riboswitch makes extensive interactions with the adenosine and sulfonium moieties of SAM but does not appear to recognize the tail of the methionine moiety. We captured a structural snapshot of the SMK box riboswitch sampling the near-cognate ligand S-adenosyl-L-homocysteine (SAH) in which SAH was found to adopt an alternative conformation and fails to make several key interactions.

  17. Computer Processor Allocator

    2004-03-01

    The Compute Processor Allocator (CPA) provides an efficient and reliable mechanism for managing and allotting processors in a massively parallel (MP) computer. It maintains information in a database on the health. configuration and allocation of each processor. This persistent information is factored in to each allocation decision. The CPA runs in a distributed fashion to avoid a single point of failure.

  18. Thematic Mapper data for forest resource allocation

    NASA Technical Reports Server (NTRS)

    Zeff, Ilene S.; Merry, Carolyn J.

    1993-01-01

    A technique for classifying a Landsat Thematic Mapper image was demonstrated on the Wayne National Forest of southeastern Ohio. The classified image was integrated into a geographic information system database, and prescriptive forest land use allocation models were developed using the techniques of cartographic modeling. Timber harvest sites and accompanying haul roads were allocated.

  19. SAM II Data and Information (HDF-EOS)

    Atmospheric Science Data Center

    2016-09-01

    ... Data obtained from the Stratospheric Aerosol Measurement (SAM) II instrument, which flew on board the Nimbus-7 ... Spatial Resolution:  The altitude profiles of aerosol extinction have a 1 km vertical resolution. Temporal ...

  20. Curiosity Shakes, Bakes, and Tastes Mars with SAM

    NASA Video Gallery

    NASA's Curiosity rover analyzed its first solid sample of Mars with a variety of instruments, including the Sample Analysis at Mars (SAM) instrument suite. Developed at NASA's Goddard Space Flight ...

  1. In-Orbit Calibration of a SAMS Triaxial Sensor Head

    NASA Technical Reports Server (NTRS)

    Chestney, Louis S.; Sicker, Ronald J.

    1996-01-01

    This report describes the results of in orbit calibration data collected for a Space Acceleration Measurement System (SAMS) Triaxial Sensor Head (TS H) and the methods used to process the data for bias and gravity levels.

  2. Eco-hydrologic Modeling of Rangelands: Evaluating a New Carbon Allocation Approach and Simulating Ecosystem Response to Changing Climate and Management Conditions

    NASA Astrophysics Data System (ADS)

    Reyes, J. J.; Tague, C.; Choate, J. S.; Adam, J. C.

    2014-12-01

    More than one-third of the United States' land cover is comprised of rangelands, which support both forage production and livestock grazing. For grasses in both semi-arid and humid environments, small changes in precipitation and temperature, as well as grazing, can have disproportionately larger impacts on ecosystem processes. For example, these areas may experience large response pulses under highly variable precipitation and other potential future changes. The ultimate goal of this study is to provide information on the interactions between management activities, climate and ecosystem processes to inform sustainable rangeland management. The specific objectives of this paper are to (1) evaluate a new carbon allocation strategy for grasses and (2) test the sensitivity of this improved strategy to changes in climate and grazing strategies. The Regional Hydro-ecologic Simulation System (RHESSys) is a process-based, watershed-scale model that simulates hydrology and biogeochemical cycling with dynamic soil and vegetation modules. We developed a new carbon allocation algorithm for partitioning net primary productivity (NPP) between roots and leaves for grasses. The 'hybrid' approach represents a balance between preferential partitioning due to environmental conditions and age-related growth. We evaluated this new allocation scheme at the point-scale at a variety of rangeland sites in the U.S. using observed biomass measurements and against existing allocation schemes used in RHESSys. Additionally, changes in the magnitude, frequency, and intensity of precipitation and temperature were used to assess ecosystem responses using our new allocation scheme. We found that changes in biomass and NPP were generally more sensitive to changes in precipitation than changes in temperature. At more arid sites, larger percent reductions in historic baseline precipitation affected biomass and NPP more negatively. We incorporated grazing impacts through biomass removal. We found that

  3. Auxiliary iron-sulfur cofactors in radical SAM enzymes.

    PubMed

    Lanz, Nicholas D; Booker, Squire J

    2015-06-01

    A vast number of enzymes are now known to belong to a superfamily known as radical SAM, which all contain a [4Fe-4S] cluster ligated by three cysteine residues. The remaining, unligated, iron ion of the cluster binds in contact with the α-amino and α-carboxylate groups of S-adenosyl-l-methionine (SAM). This binding mode facilitates inner-sphere electron transfer from the reduced form of the cluster into the sulfur atom of SAM, resulting in a reductive cleavage of SAM to methionine and a 5'-deoxyadenosyl radical. The 5'-deoxyadenosyl radical then abstracts a target substrate hydrogen atom, initiating a wide variety of radical-based transformations. A subset of radical SAM enzymes contains one or more additional iron-sulfur clusters that are required for the reactions they catalyze. However, outside of a subset of sulfur insertion reactions, very little is known about the roles of these additional clusters. This review will highlight the most recent advances in the identification and characterization of radical SAM enzymes that harbor auxiliary iron-sulfur clusters. This article is part of a Special Issue entitled: Fe/S proteins: Analysis, structure, function, biogenesis and diseases. PMID:25597998

  4. Optimizing reproductive phenology in a two-resource world: a dynamic allocation model of plant growth predicts later reproduction in phosphorus-limited plants

    PubMed Central

    Nord, Eric A.; Shea, Katriona; Lynch, Jonathan P.

    2011-01-01

    Background and Aims Timing of reproduction is a key life-history trait that is regulated by resource availability. Delayed reproduction in soils with low phosphorus availability is common among annuals, in contrast to the accelerated reproduction typical of other low-nutrient environments. It is hypothesized that this anomalous response arises from the high marginal value of additional allocation to root growth caused by the low mobility of phosphorus in soils. Methods To better understand the benefits and costs of such delayed reproduction, a two-resource dynamic allocation model of plant growth and reproduction is presented. The model incorporates growth, respiration, and carbon and phosphorus acquisition of both root and shoot tissue, and considers the reallocation of resources from senescent leaves. The model is parameterized with data from Arabidopsis and the optimal reproductive phenology is explored in a range of environments. Key Results The model predicts delayed reproduction in low-phosphorus environments. Reproductive timing in low-phosphorus environments is quite sensitive to phosphorus mobility, but is less sensitive to the temporal distribution of mortality risks. In low-phosphorus environments, the relative metabolic cost of roots was greater, and reproductive allocation reduced, compared with high-phosphorus conditions. The model suggests that delayed reproduction in response to low phosphorus availability may be reduced in plants adapted to environments where phosphorus mobility is greater. Conclusions Delayed reproduction in low-phosphorus soils can be a beneficial response allowing for increased acquisition and utilization of phosphorus. This finding has implications both for efforts to breed crops for low-phosphorus soils, and for efforts to understand how climate change may impact plant growth and productivity in low-phosphorus environments. PMID:21712299

  5. The dynamic of the annual carbon allocation to wood in European tree species is consistent with a combined source-sink limitation of growth: implications for modelling

    NASA Astrophysics Data System (ADS)

    Guillemot, J.; Martin-StPaul, N. K.; Dufrene, E.; Francois, C.; Soudani, K.; Ourcival, J. M.; Delpierre, N.

    2015-05-01

    appeared to strongly limit growth only in temperate deciduous species. We provide an evaluation of the spatio-temporal dynamics of the annual C allocation to wood in French forests. Our study supports the premise that the growth of European tree species is subject to complex control processes that include both source and sink limitations. The relative influences of the growth drivers strongly vary with time and across spatial ecological gradients. We suggest a straightforward modelling framework with which to implement these combined forest growth limitations into terrestrial biosphere models.

  6. HPA and SAM axis responses as correlates of self- vs parental ratings of anxiety in boys with an Autistic Disorder.

    PubMed

    Bitsika, Vicki; Sharpley, Christopher F; Sweeney, John A; McFarlane, James R

    2014-03-29

    Anxiety and Autistic Disorder (AD) are both neurological conditions and both disorders share some features that make it difficult to precisely allocate specific symptoms to each disorder. HPA and SAM axis activities have been conclusively associated with anxiety, and may provide a method of validating anxiety rating scale assessments given by parents and their children with AD about those children. Data from HPA axis (salivary cortisol) and SAM axis (salivary alpha amylase) responses were collected from a sample of 32 high-functioning boys (M age=11yr) with an Autistic Disorder (AD) and were compared with the boys' and their mothers' ratings of the boys' anxiety. There was a significant difference between the self-ratings given by the boys and ratings given about them by their mothers. Further, only the boys' self-ratings of their anxiety significantly predicted the HPA axis responses and neither were significantly related to SAM axis responses. Some boys showed cortisol responses which were similar to that previously reported in children who had suffered chronic and severe anxiety arising from stressful social interactions. As well as suggesting that some boys with an AD can provide valid self-assessments of their anxiety, these data also point to the presence of very high levels of chronic HPA-axis arousal and consequent chronic anxiety in these boys. PMID:24412722

  7. Total maximum allocated load calculation of nitrogen pollutants by linking a 3D biogeochemical-hydrodynamic model with a programming model in Bohai Sea

    NASA Astrophysics Data System (ADS)

    Dai, Aiquan; Li, Keqiang; Ding, Dongsheng; Li, Yan; Liang, Shengkang; Li, Yanbin; Su, Ying; Wang, Xiulin

    2015-12-01

    The equal percent removal (EPR) method, in which pollutant reduction ratio was set as the same in all administrative regions, failed to satisfy the requirement for water quality improvement in the Bohai Sea. Such requirement was imposed by the developed Coastal Pollution Total Load Control Management. The total maximum allocated load (TMAL) of nitrogen pollutants in the sea-sink source regions (SSRs) around the Bohai Rim, which is the maximum pollutant load of every outlet under the limitation of water quality criteria, was estimated by optimization-simulation method (OSM) combined with loop approximation calculation. In OSM, water quality is simulated using a water quality model and pollutant load is calculated with a programming model. The effect of changes in pollutant loads on TMAL was discussed. Results showed that the TMAL of nitrogen pollutants in 34 SSRs was 1.49×105 ton/year. The highest TMAL was observed in summer, whereas the lowest in winter. TMAL was also higher in the Bohai Strait and central Bohai Sea and lower in the inner area of the Liaodong Bay, Bohai Bay and Laizhou Bay. In loop approximation calculation, the TMAL obtained was considered satisfactory for water quality criteria as fluctuation of concentration response matrix with pollutant loads was eliminated. Results of numerical experiment further showed that water quality improved faster and were more evident under TMAL input than that when using the EPR method

  8. SAMS Acceleration Measurements on Mir from June to November 1995

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard; Hrovat, Ken; Moskowitz, Milton; McPherson, Kevin

    1996-01-01

    The NASA Microgravity Science and Applications Division (MSAD) sponsors science experiments on a variety of microgravity carriers, including sounding rockets, drop towers, parabolic aircraft, and Orbiter missions. The MSAD sponsors the Space Acceleration Measurement System (SAMS) to support microgravity science experiments with acceleration measurements to characterize the microgravity environment to which the experiments were exposed. The Principal Investigator Microgravity Services project at the NASA Lewis Research Center supports principal investigators of microgravity experiments as they evaluate the effects of varying acceleration levels on their experiments. In 1993, a cooperative effort was started between the United States and Russia involving science utilization of the Russian Mir space station by scientists from the United States and Russia. MSAD is currently sponsoring science experiments participating in the Shuttle-Mir Science Program in cooperation with the Russians on the Mir space station. Included in the complement of MSAD experiments and equipment is a SAMS unit In a manner similar to Orbiter mission support, the SAMS unit supports science experiments from the U.S. and Russia by measuring the microgravity environment during experiment operations. The initial SAMS supported experiment was a Protein Crystal Growth (PCG) experiment from June to November 1995. SAMS data were obtained during the PCG operations on Mir in accordance with the PCG Principal Investigator's requirements. This report presents an overview of the SAMS data recorded to support this PCG experiment. The report contains plots of the SAMS 100 Hz sensor head data as an overview of the microgravity environment, including the STS-74 Shuttle-Mir docking.

  9. Models of knot and stem development in black spruce trees indicate a shift in allocation priority to branches when growth is limited

    PubMed Central

    Duchateau, Emmanuel; Auty, David; Mothe, Frédéric; Longuetaud, Fleur; Ung, Chhun Huor

    2015-01-01

    The branch autonomy principle, which states that the growth of individual branches can be predicted from their morphology and position in the forest canopy irrespective of the characteristics of the tree, has been used to simplify models of branch growth in trees. However, observed changes in allocation priority within trees towards branches growing in light-favoured conditions, referred to as ‘Milton’s Law of resource availability and allocation,’ have raised questions about the applicability of the branch autonomy principle. We present models linking knot ontogeny to the secondary growth of the main stem in black spruce (Picea mariana (Mill.) B.S.P.), which were used to assess the patterns of assimilate allocation over time, both within and between trees. Data describing the annual radial growth of 445 stem rings and the three-dimensional shape of 5,377 knots were extracted from optical scans and X-ray computed tomography images taken along the stems of 10 trees. Total knot to stem area increment ratios (KSR) were calculated for each year of growth, and statistical models were developed to describe the annual development of knot diameter and curvature as a function of stem radial increment, total tree height, stem diameter, and the position of knots along an annual growth unit. KSR varied as a function of tree age and of the height to diameter ratio of the stem, a variable indicative of the competitive status of the tree. Simulations of the development of an individual knot showed that an increase in the stem radial growth rate was associated with an increase in the initial growth of the knot, but also with a shorter lifespan. Our results provide support for ‘Milton’s Law,’ since they indicate that allocation priority is given to locations where the potential return is the highest. The developed models provided realistic simulations of knot morphology within trees, which could be integrated into a functional-structural model of tree growth and above

  10. Developing an Agent-based Model for the Depot-based Water Allocation System in the Bakken Field in Western North Dakota

    NASA Astrophysics Data System (ADS)

    Lin, T.; Lin, Z.; Lim, S.; Borders, M.

    2015-12-01

    The oil production at the Bakken Shale increased more than ten times from 2008 to 2013 due to technological advancement in hydraulic fracturing and North Dakota has become the second largest oil producing state in the U.S. behind only Texas since 2012. On average it requires about 2-4 million gallons of freshwater to complete one oil well in the Bakken field and the number of oil well completions (i.e., hydraulic fracturing) in the Bakken field increased from 500 in 2008 to 2085 in 2013. A large quantity of freshwater used for hydraulic fracturing renders a significant impact on water resource management in the semi-arid region. A novel water allocation system - water depots - was spontaneously created to distribute surface and ground water for industrial uses. A GIS-based multi-agent model is developed to simulate the emergent patterns and dynamics of the water depot-based water allocation system and to explore its economic and environmental consequences. Four different types of water depot are defined as agents and water price, climate condition, water source, geology, and other physical and economic constraints are considered in the model. Decentralized optimization algorithm will be used to determine the agents' behaviors. The agent-based model for water depots will be coupled with hydrological models to improve the region's water resources management.

  11. SAM68: Signal Transduction and RNA Metabolism in Human Cancer

    PubMed Central

    Frisone, Paola; Pradella, Davide; Di Matteo, Anna; Belloni, Elisa; Ghigna, Claudia; Paronetto, Maria Paola

    2015-01-01

    Alterations in expression and/or activity of splicing factors as well as mutations in cis-acting splicing regulatory sequences contribute to cancer phenotypes. Genome-wide studies have revealed more than 15,000 tumor-associated splice variants derived from genes involved in almost every aspect of cancer cell biology, including proliferation, differentiation, cell cycle control, metabolism, apoptosis, motility, invasion, and angiogenesis. In the past decades, several RNA binding proteins (RBPs) have been implicated in tumorigenesis. SAM68 (SRC associated in mitosis of 68 kDa) belongs to the STAR (signal transduction and activation of RNA metabolism) family of RBPs. SAM68 is involved in several steps of mRNA metabolism, from transcription to alternative splicing and then to nuclear export. Moreover, SAM68 participates in signaling pathways associated with cell response to stimuli, cell cycle transitions, and viral infections. Recent evidence has linked this RBP to the onset and progression of different tumors, highlighting misregulation of SAM68-regulated splicing events as a key step in neoplastic transformation and tumor progression. Here we review recent studies on the role of SAM68 in splicing regulation and we discuss its contribution to aberrant pre-mRNA processing in cancer. PMID:26273626

  12. Ensuring GRID resource availability with the SAM framework in LHCb

    NASA Astrophysics Data System (ADS)

    Closier, J.; Paterson, S.; Santinelli, R.

    2008-07-01

    The LHCb experiment has chosen to use the SAM framework (Service Availability Monitoring Environment from EGEE-II) [1] make extensive tests of the LHCb environment at all the accessible grid resources. The availability and the proper definition of the local Computing and Storage Elements, user interfaces as well as the WLCG software environment are checked. The SAM framework is also used to pre-install the LHCb applications in the shared software area provided by each site. The deployment of the LHCb applications is based on a python tool developed inside the experiment. It is used for software management including incremental installation of interdependent packages and clean package removal. After the application software is installed a validation test of the whole MC chain is run. According to the results of the experiment specific SAM tests, the sites are (re)integrated into the LHCb production system managed by DIRAC [2]. The possibility of automated dynamic site certification using the SAM test suite is explored. This paper will describe the various ways of the LHCb use of the SAM framework. Practical experience in the recent production runs, current limitations and future developments will be presented.

  13. The hydrological and economic impacts of changing water allocation in political regions within the peri-urban South Creek catchment in Western Sydney I: Model development

    NASA Astrophysics Data System (ADS)

    Davidson, Brian; Malano, Hector; Nawarathna, Bandara; Maheshwari, Basant

    2013-08-01

    In this paper an integrated model of the hydrological and economic impacts of deploying water within the political divisions in the South Creek catchment of the ‘peri-urban’ region of Western Sydney is presented. This model enables an assessment of the hydrological and economic merits of different water allocation-substitution strategies, both over the whole catchment and in each political region and jurisdiction within it, to be undertaken. Not only are the differences in the water allocated to each region and use revealed, but also the net present values associated with each use within each region. In addition, it is possible to determine measures of equity in water distribution using this approach. It was found that over a period from 2008 to 2031 the South Creek catchment in total would on average use approximately 50,600 ML of potable water a year, the vast majority of this is used in the two urban regions of Penrith and Blacktown. Agricultural water use was also greatest in these two regions. Over this period the allocation system was estimated to have a small net present value of approximately A301 million and the Benefit-Cost ratio was estimated to be 1.06. The urban regions of Penrith and Blacktown and the rural region of Hawkesbury were estimated to have returned a net positive benefit of A76 million, A246 million and A39 million (respectively), while water to Liverpool and Camden was delivered at a loss of A7 million and A52 million over the period assessed. It was found that across the catchment a fair degree of both physical and economic equity occurred between regions, with the exception of Liverpool, which was over endowed with water and paid a high cost for it.

  14. Improved waiting-list outcomes in Argentina after the adoption of a model for end-stage liver disease-based liver allocation policy.

    PubMed

    Cejas, Nora Gabriela; Villamil, Federico G; Lendoire, Javier C; Tagliafichi, Viviana; Lopez, Arturo; Krogh, Daniela Hansen; Soratti, Carlos A; Bisigniano, Liliana

    2013-07-01

    In July 2005, Argentina became the first country after the United States to introduce the Model for End-Stage Liver Disease (MELD) for organ allocation. In this study, we investigated waiting-list (WL) outcomes (n = 3272) and post-liver transplantation (LT) survival in 2 consecutive periods of 5 years before and after the implementation of a MELD-based allocation policy. Data were obtained from the database of the national institute for organ allocation in Argentina. After the adoption of the MELD system, there were significant reductions in WL mortality [28.5% versus 21.9%, P < 0.001, hazard ratio (HR) = 1.57, 95% confidence interval (CI) = 1.37-1.81] and total dropout rates (38.6% versus 29.1%, P < 0.001, HR = 1.31, 95% CI = 1.16-1.48) despite significantly less LT accessibility (57.4% versus 50.7%, P < 0.001, HR = 1.53, 95% CI = 1.39-1.68). The annual number of deaths per 1000 patient-years at risk decreased from 273 in 2005 to 173 in 2010, and the number of LT procedures per 1000 patient-years at risk decreased from 564 to 422. MELD and Model for End-Stage Liver Disease-Sodium scores were excellent predictors of 3-month WL mortality with c statistics of 0.828 and 0.857, respectively (P < 0.001). No difference was observed in 1-year posttransplant survival between the 2 periods (81.1% versus 81.3%). Although patients with a MELD score > 30 had lower posttransplant survival, the global accuracy of the score for predicting outcomes was poor, as indicated by a c statistic of only 0.523. Patients with granted MELD exceptions (158 for hepatocellular carcinoma and 52 for other reasons) had significantly higher access to LT (80.4%) in comparison with nonexception patients with equivalent listing priority (MELD score = 18-25; 54.6%, P < 0.001, HR = 0.49, 95% CI = 0.40-0.61). In conclusion, the adoption of the MELD model in Argentina has resulted in improved liver organ allocation without compromising

  15. A Sophomore-to-Junior Mentoring Program that Works: The SAM Program at the University of Texas Pan American

    ERIC Educational Resources Information Center

    Reyes, Maria Elena

    2012-01-01

    In an effort to increase the retention rates of college sophomores in a Hispanic Serving Institution in south Texas, university administrators created and implemented a successful peer mentoring model, the Sophomore Academic Mentoring (SAM) Program. Results suggest that the program has contributed to an increase in retention for second year,…

  16. Sarm1-mediated axon degeneration requires both SAM and TIR interactions.

    PubMed

    Gerdts, Josiah; Summers, Daniel W; Sasaki, Yo; DiAntonio, Aaron; Milbrandt, Jeffrey

    2013-08-14

    Axon degeneration is an evolutionarily conserved pathway that eliminates damaged or unneeded axons. Manipulation of this poorly understood pathway may allow treatment of a wide range of neurological disorders. In an RNAi-based screen performed in cultured mouse DRG neurons, we observed strong suppression of injury-induced axon degeneration upon knockdown of Sarm1 [SARM (sterile α-motif-containing and armadillo-motif containing protein)]. We find that a SARM-dependent degeneration program is engaged by disparate neuronal insults: SARM ablation blocks axon degeneration induced by axotomy or vincristine treatment, while SARM acts in parallel with a soma-derived caspase-dependent pathway following trophic withdrawal. SARM is a multidomain protein that associates with neuronal mitochondria. Deletion of the N-terminal mitochondrial localization sequence disrupts SARM mitochondrial localization in neurons but does not alter its ability to promote axon degeneration. In contrast, mutation of either the SAM (sterile α motif) or TIR (Toll-interleukin-1 receptor) domains abolishes the ability of SARM to promote axonal degeneration, while a SARM mutant containing only these domains elicits axon degeneration and nonapoptotic neuronal death even in the absence of injury. Protein-protein interaction studies demonstrate that the SAM domains are necessary and sufficient to mediate SARM-SARM binding. SARM mutants lacking a TIR domain bind full-length SARM and exhibit strong dominant-negative activity. These results indicate that SARM plays an integral role in the dismantling of injured axons and support a model in which SAM-mediated multimerization is necessary for TIR-dependent engagement of a downstream destruction pathway. These findings suggest that inhibitors of SAM and TIR interactions represent therapeutic candidates for blocking pathological axon loss and neuronal cell death. PMID:23946415

  17. SAM-T08, HMM-based protein structure prediction

    PubMed Central

    Karplus, Kevin

    2009-01-01

    The SAM-T08 web server is a protein structure prediction server that provides several useful intermediate results in addition to the final predicted 3D structure: three multiple sequence alignments of putative homologs using different iterated search procedures, prediction of local structure features including various backbone and burial properties, calibrated E-values for the significance of template searches of PDB and residue–residue contact predictions. The server has been validated as part of the CASP8 assessment of structure prediction as having good performance across all classes of predictions. The SAM-T08 server is available at http://compbio.soe.ucsc.edu/SAM_T08/T08-query.html PMID:19483096

  18. Description of ferrocenylalkylthiol SAMs on gold by molecular dynamics simulations.

    PubMed

    Goujon, F; Bonal, C; Limoges, B; Malfreyt, P

    2009-08-18

    Molecular dynamics simulations of mixed monolayers consisting of Fc(CH2)12S-/C10S-Au SAMs are carried out to calculate structural (density profiles, angular distributions, positions of atoms) and energetic properties. The purpose of this paper is to explore the possible inhomogeneity of the neutral ferrocene moieties within the monolayer. Five systems have been studied using different grafting densities for the ferrocenylalkylthiolates. The angular distributions are described in terms of the relative contributions from isolated and clustered ferrocene moieties in the binary SAMs. It is shown that the energetic contributions strongly depend on the state of the ferrocene. The ability of molecular dynamics simulations to enable better understanding the SAM structure is illustrated in this work. PMID:19449821

  19. Allocation without locking

    SciTech Connect

    Appel, A.W.

    1988-01-01

    In a programming environment with both concurrency and automatic garbage collection, the allocation and initialization of a new record is a sensitive matter: if it is interrupted halfway through, the allocating process may be in a state that the garbage collector can't understand. In particular, the collector won't know which words of the new record have been initialized and which are meaningless (and unsafe to transverse). For this reason, parallel implementations usually use a locking or semaphore mechanism to ensure that allocation is an atomic operation. The locking significantly adds to the cost of allocation. This paper shows that allocation can run extremely quickly even in a multi-thread environment: open-coded, without locking.

  20. SuMoToRI, an Ecophysiological Model to Predict Growth and Sulfur Allocation and Partitioning in Oilseed Rape (Brassica napus L.) Until the Onset of Pod Formation.

    PubMed

    Brunel-Muguet, Sophie; Mollier, Alain; Kauffmann, François; Avice, Jean-Christophe; Goudier, Damien; Sénécal, Emmanuelle; Etienne, Philippe

    2015-01-01

    Sulfur (S) nutrition in rapeseed (Brassica napus L.) is a major concern for this high S-demanding crop, especially in the context of soil S oligotrophy. Therefore, predicting plant growth, S plant allocation (between the plant's compartments) and S pool partitioning (repartition of the mobile-S vs. non-mobile-S fractions) until the onset of reproductive phase could help in the diagnosis of S deficiencies during the early stages. For this purpose, a process-based model, SuMoToRI (Sulfur Model Toward Rapeseed Improvement), was developed up to the onset of pod formation. The key features rely on (i) the determination of the S requirements used for growth (structural and metabolic functions) through critical S dilution curves and (ii) the estimation of a mobile pool of S that is regenerated by daily S uptake and remobilization from senescing leaves. This study describes the functioning of the model and presents the model's calibration and evaluation. SuMoToRI was calibrated and evaluated with independent datasets from greenhouse experiments under contrasting S supply conditions. It is run with a small number of parameters with generic values, except in the case of the radiation use efficiency, which was shown to be modulated by S supply. The model gave satisfying predictions of the dynamics of growth, S allocation between compartments and S partitioning, such as the mobile-S fraction in the leaves, which is an indicator of the remobilization potential toward growing sinks. The mechanistic features of SuMoToRI provide a process-based framework that has enabled the description of the S remobilizing process in a species characterized by senescence during the vegetative phase. We believe that this model structure could be useful for modeling S dynamics in other arable crops that have similar senescence-related characteristics. PMID:26635825

  1. The methylthiolation reaction mediated by the Radical-SAM enzymes

    PubMed Central

    Atta, Mohamed; Arragain, Simon; Fontecave, Marc; Mulliez, Etienne; Hunt, John F.; Luff, Jon D.; Forouhar, Farhad

    2014-01-01

    Over the past ten years, considerable progress has been made in our understanding of the mechanistic enzymology of the Radical-SAM enzymes. It is now clear that these enzymes appear to be involved in a remarkably wide range of chemically challenging reactions. This review article highlights mechanistic and structural aspects of the methylthiotransferases (MTTases) sub-class of the Radical-SAM enzymes. The mechanism of methylthio insertion, now observed to be performed by three different enzymes is an exciting unsolved problem. PMID:22178611

  2. SuMoToRI, an Ecophysiological Model to Predict Growth and Sulfur Allocation and Partitioning in Oilseed Rape (Brassica napus L.) Until the Onset of Pod Formation

    PubMed Central

    Brunel-Muguet, Sophie; Mollier, Alain; Kauffmann, François; Avice, Jean-Christophe; Goudier, Damien; Sénécal, Emmanuelle; Etienne, Philippe

    2015-01-01

    Sulfur (S) nutrition in rapeseed (Brassica napus L.) is a major concern for this high S-demanding crop, especially in the context of soil S oligotrophy. Therefore, predicting plant growth, S plant allocation (between the plant’s compartments) and S pool partitioning (repartition of the mobile-S vs. non-mobile-S fractions) until the onset of reproductive phase could help in the diagnosis of S deficiencies during the early stages. For this purpose, a process-based model, SuMoToRI (Sulfur Model Toward Rapeseed Improvement), was developed up to the onset of pod formation. The key features rely on (i) the determination of the S requirements used for growth (structural and metabolic functions) through critical S dilution curves and (ii) the estimation of a mobile pool of S that is regenerated by daily S uptake and remobilization from senescing leaves. This study describes the functioning of the model and presents the model’s calibration and evaluation. SuMoToRI was calibrated and evaluated with independent datasets from greenhouse experiments under contrasting S supply conditions. It is run with a small number of parameters with generic values, except in the case of the radiation use efficiency, which was shown to be modulated by S supply. The model gave satisfying predictions of the dynamics of growth, S allocation between compartments and S partitioning, such as the mobile-S fraction in the leaves, which is an indicator of the remobilization potential toward growing sinks. The mechanistic features of SuMoToRI provide a process-based framework that has enabled the description of the S remobilizing process in a species characterized by senescence during the vegetative phase. We believe that this model structure could be useful for modeling S dynamics in other arable crops that have similar senescence-related characteristics. PMID:26635825

  3. Integrating a distributed hydrological model and SEEA-Water for improving water account and water allocation management under a climate change context.

    NASA Astrophysics Data System (ADS)

    Jauch, Eduardo; Almeida, Carina; Simionesei, Lucian; Ramos, Tiago; Neves, Ramiro

    2015-04-01

    The crescent demand and situations of water scarcity and droughts are a difficult problem to solve by water managers, with big repercussions in the entire society. The complexity of this question is increased by trans-boundary river issues and the environmental impacts of the usual adopted solutions to store water, like reservoirs. To be able to answer to the society requirements regarding water allocation in a sustainable way, the managers must have a complete and clear picture of the present situation, as well as being able to understand the changes in the water dynamics both in the short and long time period. One of the available tools for the managers is the System of Environmental-Economic Accounts for Water (SEEA-Water), a subsystem of SEEA with focus on water accounts, developed by the United Nations Statistical Division (UNSD) in collaboration with the London Group on Environmental Accounting, This system provides, between other things, with a set of tables and accounts for water and water related emissions, organizing statistical data making possible the derivation of indicators that can be used to assess the relations between economy and environment. One of the main issues with the SEEA-Water framework seems to be the requirement of large amounts of data, including field measurements of water availability in rivers/lakes/reservoirs, soil and groundwater, as also precipitation, irrigation and other water sources and uses. While this is an incentive to collecting and using data, it diminishes the usefulness of the system on countries where this data is not yet available or is incomplete, as it can lead to a poor understanding of the water availability and uses. Distributed hydrological models can be used to fill missing data required by the SEEA-Water framework. They also make it easier to assess different scenarios (usually soil use, water demand and climate changes) for a better planning of water allocation. In the context of the DURERO project (www

  4. Optimal Resource Allocation in Library Systems

    ERIC Educational Resources Information Center

    Rouse, William B.

    1975-01-01

    Queueing theory is used to model processes as either waiting or balking processes. The optimal allocation of resources to these processes is defined as that which maximizes the expected value of the decision-maker's utility function. (Author)

  5. Radical-Mediated Enzymatic Methylation: A Tale of Two SAMS

    PubMed Central

    2011-01-01

    Methylation is an essential and ubiquitous reaction that plays an important role in a wide range of biological processes. Most biological methylations use S-adenosylmethionine (SAM) as the methyl donor and proceed via an SN2 displacement mechanism. However, researchers have discovered an increasing number of methylations that involve radical chemistry. The enzymes known to catalyze these reactions all belong to the radical SAM superfamily. This family of enzymes utilizes a specialized [4Fe-4S] cluster for reductive cleavage of SAM to yield a highly reactive 5'-deoxyadenosyl (dAdo) radical. Radical chemistry is then imposed on a variety of organic substrates, leading to a diverse array of transformations. Until recently, researchers had not fully understood how these enzymes employ radical chemistry to mediate a methyl transfer reaction. Sequence analyses reveal that the currently identified radical SAM methyltransferases (RSMTs) can be grouped into three classes, which appear distinct in protein architecture and mechanism. Class A RSMTs mainly include the rRNA methyltransferases RlmN and Cfr from various origins. As exemplified by Escherichia coli RlmN, these proteins have a single canonical radical SAM core domain that includes an (βα)6 partial barrel most similar to that of pyruvate formate lyase-activase. The exciting recent studies on RlmN and Cfr are beginning to provide insights into the intriguing chemistry of class A RSMTs. These enzymes utilize a methylene radical generated on a unique methylated cysteine residue. However, based on the variety of substrates used by the other classes of RSMTs, alternative mechanisms are likely to be discovered. Class B RSMTs contain a proposed N-terminal cobalamin binding domain in addition to a radical SAM domain at the C-terminus. This class of proteins methylates diverse substrates at inert sp3 carbons, aromatic heterocycles, and phosphinates, possibly involving a cobalamin-mediated methyl transfer process. Class C

  6. EFFECTS OF POLYCYCLIC AROMATIC HYDROCARBON OF SAM-COATED ELECTRODES USING FERRYICYANIDE AS THE REDOX INDICATOR

    EPA Science Inventory

    Electrochemical responses on self-assembled monolayer (SAM)-coated polycrystalline gold electrodes were investigated using cyclic voltammetry and square wave voltammetry with a three electrode system. Experimental results show potential in the application of pyrene-imprinted SAM...

  7. SAMS Acceleration Measurement on Mir From March to September 1996

    NASA Technical Reports Server (NTRS)

    Moskowitz, Milton E.; Hrovat, Ken; Truong, Duc; Reckart, Timothy

    1997-01-01

    During NASA Increment 2 (March to September 1996), over 15 gigabytes of acceleration data were collected by the Space Acceleration Measurement System (SAMS) onboard the Russian Space Station, Mir. The data were recorded on 55 optical disks and were returned to Earth on STS-79. During this time, SAMS data were collected in the Kristall and Kvant modules, and in the Priroda module to support the following experiments: the Queen's University Experiments in Liquid Diffusion (QUELD), the Technological Evaluation of the MIM (TEM), the Forced Flow Flame Spreading Test (FFFT), and Candle Flames in Microgravity (CFM). This report points out some of the salient features of the microgravity environment to which these experiments were exposed. Also documented are mission events of interest such as the docked phase of STS-76 operations, an extravehicular activity (EVA) to install and deploy solar panels on the Kvant module, a Progress engine burn to raise Mir's altitude, and an on-orbit SAMS calibration procedure. Also included are a description of the Mir module orientations, and the panel notations within the modules. This report presents an overview of the SAMS acceleration measurements recorded by 10 Hz and 100 Hz sensor heads. Variations in the acceleration environment caused by unique activities such as crew exercise and life-support fans are presented. The analyses included herein complement those presented in previous mission summary reports published by the Principal Investigator Microgravity Services (PIMS) group.

  8. Social Activity Method (SAM): A Fractal Language for Mathematics

    ERIC Educational Resources Information Center

    Dowling, Paul

    2013-01-01

    In this paper I shall present and develop my organisational language, "social activity method" (SAM), and illustrate some of its applications. I shall introduce a new scheme for "modes of recontextualisation" that enables the analysis of the ways in which one activity--which might be school mathematics or social research or any…

  9. Information System through ANIS at CeSAM

    NASA Astrophysics Data System (ADS)

    Moreau, C.; Agneray, F.; Gimenez, S.

    2015-09-01

    ANIS (AstroNomical Information System) is a web generic tool developed at CeSAM to facilitate and standardize the implementation of astronomical data of various kinds through private and/or public dedicated Information Systems. The architecture of ANIS is composed of a database server which contains the project data, a web user interface template which provides high level services (search, extract and display imaging and spectroscopic data using a combination of criteria, an object list, a sql query module or a cone search interfaces), a framework composed of several packages, and a metadata database managed by a web administration entity. The process to implement a new ANIS instance at CeSAM is easy and fast : the scientific project has to submit data or a data secure access, the CeSAM team installs the new instance (web interface template and the metadata database), and the project administrator can configure the instance with the web ANIS-administration entity. Currently, the CeSAM offers through ANIS a web access to VO compliant Information Systems for different projects (HeDaM, HST-COSMOS, CFHTLS-ZPhots, ExoDAT,...).

  10. Skill Acquisition Measures (SAM). Elementary Mathematics Level IV. Teacher's Manual.

    ERIC Educational Resources Information Center

    Lancaster City School District, PA.

    The Skill Acquisition Measures (SAM) were designed by the Lancaster (Pennsylvania) School District as criterion referenced tests for mathematics. This manual consists of copies of the student test forms for level 4, with additional information for the teacher's use. Each of the test items is presented with the correct answers and the criteria for…

  11. Yield estimation from hyperspectral imagery using Spectral Angle Mapper (SAM)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetation indices (VIs) derived from remotely sensed imagery are commonly used to estimate crop yields. Spectral angle mapper (SAM) provides an alternative approach to quantifying the spectral differences among all pixels in imagery and therefore has the potential for mapping yield variability. The...

  12. 78 FR 47695 - Sam Rayburn Dam Power Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-06

    ... September 30, 2013 (77 FR 67813, November. 14, 2012). The Administrator, Southwestern Power Administration (Southwestern), has prepared Current and Revised 2013 Power Repayment Studies which show the need for an... Southwestern Power Administration Sam Rayburn Dam Power Rate AGENCY: Southwestern Power Administration,...

  13. 77 FR 67813 - Sam Rayburn Dam Project Power Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-14

    ... Rayburn power rate extension were announced by a Federal Register (77 FR 50493) notice published on August... published notice in the Federal Register, (77 FR 50493), of the proposed rate extension for the Rayburn... Southwestern Power Administration Sam Rayburn Dam Project Power Rate AGENCY: Southwestern Power...

  14. Skill Acquisition Measures (SAM). Elementary Mathematics Level V. Teacher's Manual.

    ERIC Educational Resources Information Center

    Lancaster City School District, PA.

    The Skill Acquisition Measures (SAM) were designed by the Lancaster (Pennsylvania) School District as criterion referenced tests for mathematics. This manual consists of copies of the student test forms for level 5, with additional information for the teacher's use. Each of the test items is presented with the correct answers and the criteria for…

  15. Dynamics within alkylsiloxane SAMs studied by sensitive dielectric spectroscopy

    NASA Astrophysics Data System (ADS)

    Scott, Mary; Stevens, Derrick; Bochinski, Jason; Clarke, Laura

    2009-03-01

    Self assembled monolayers (SAMs) are a ubiquitous tool in modern research and their static structure has been extensively studied. Fewer investigations have addressed dynamics within these systems; however, such motions within SAMs will affect surface properties such as friction and blocking ability (permeability). In this study, sensitive, dielectric spectroscopy over a broad temperature range (4-400 K) has been employed to study relaxations within planar alkylsiloxane SAMs[1] . Highly disordered SAMs of varying density were grown by vapor deposition. Two dielectric relaxations were observed. The first, a polyethylene-like relaxation similar to that previously reported in phase-segregated alkyl side-chain polymers, is observed for all films with alkyl chains containing four or more carbons. This is an interacting or glassy relaxation. The second motion, which is observable only at high film densities, is a local mode, which follows an Arrhenius dependence on temperature, and has been previously assigned to a sub-chain rotation. [1] M.C. Scott, D.R. Stevens, J.R. Bochinski, L.I. Clarke, ACS Nano. DOI: 10.1021/nn800543j.

  16. Fabrication of self-assembled monolayers (SAMs) and inorganic micropattern on flexible polymer substrate.

    PubMed

    Xiang, Junhui; Zhu, Peixin; Masuda, Yoshitake; Koumoto, Kunihito

    2004-04-13

    By grafting (aminopropyl)triethoxysilane (APTES) as the buffer layer on poly(ethylene terephthalate) (PET) surface, the SAMs ofoctadecyltrichlorosilane (OTS), phenyltrichlorosilane (PTCS), vinyltrichlorosilane (VTCS), andp-tolyltrichlorosilane (TTCS) were fabricated on the flexible polymer substrate. The properties of SAMs were accurately controlled by adjusting the immersing time of substrates in the solutions and the concentration of the solutions. The SAMs acted as templates, and TiO2 micropattern was successfully deposited on OTS, TTCS, and PTCS SAMs. PMID:15875858

  17. Selective Plasma Deposition of Fluorocarbon Films on SAMs

    NASA Technical Reports Server (NTRS)

    Crain, Mark M., III; Walsh, Kevin M.; Cohn, Robert W.

    2006-01-01

    A dry plasma process has been demonstrated to be useful for the selective modification of self-assembled monolayers (SAMs) of alkanethiolates. These SAMs are used, during the fabrication of semiconductor electronic devices, as etch masks on gold layers that are destined to be patterned and incorporated into the devices. The selective modification involves the formation of fluorocarbon films that render the SAMs more effective in protecting the masked areas of the gold against etching by a potassium iodide (KI) solution. This modification can be utilized, not only in the fabrication of single electronic devices but also in the fabrication of integrated circuits, microelectromechanical systems, and circuit boards. In the steps that precede the dry plasma process, a silicon mold in the desired pattern is fabricated by standard photolithographic techniques. A stamp is then made by casting polydimethylsiloxane (commonly known as silicone rubber) in the mold. The stamp is coated with an alkanethiol solution, then the stamp is pressed on the gold layer of a device to be fabricated in order to deposit the alkanethiol to form an alkanethiolate SAM in the desired pattern (see figure). Next, the workpiece is exposed to a radio-frequency plasma generated from a mixture of CF4 and H2 gases. After this plasma treatment, the SAM is found to be modified, while the exposed areas of gold remain unchanged. This dry plasma process offers the potential for forming masks superior to those formed in a prior wet etching process. Among the advantages over the wet etching process are greater selectivity, fewer pin holes in the masks, and less nonuniformity of the masks. The fluorocarbon films formed in this way may also be useful as intermediate layers for subsequent fabrication steps and as dielectric layers to be incorporated into finished products.

  18. The Unobtrusive Memory Allocator

    2003-03-31

    This library implements a memory allocator/manager which ask its host program or library for memory refions to manage rather than requesting them from the operating system. This allocator supports multiple distinct heaps within a single executable, each of which may grow either upward or downward in memory. The GNU mmalloc library has been modified in such a way that its allocation algorithms have been preserved, but the manner in which it obtains regions to managemore » has been changed to request memory from the host program or library. Additional modifications allow the allocator to manage each heap as either upward or downward-growing. By allowing the hosting program or library to determine what memory is managed, this package allows a greater degree of control than other memory allocation/management libraries. Additional distinguishing features include the ability to manage multiple distinct heaps with in a single executable, each of which may grow either upward or downward in memory. The most common use of this library is in conjunction with the Berkeley Unified Parallel C (UPC) Runtime Library. This package is a modified version of the LGPL-licensed "mmalloc" allocator from release 5.2 of the "gdb" debugger's source code.« less

  19. Isothiourea-Mediated Organocatalytic Michael Addition-Lactonization on a Surface: Modification of SAMs on Silicon Oxide Substrates.

    PubMed

    Chisholm, Ross; Parkin, John D; Smith, Andrew D; Hähner, Georg

    2016-04-01

    Tailoring the functionality of self-assembled monolayers (SAMs) can be achieved either by depositing prefunctionalized molecules with the appropriate terminal groups or by chemical modification of an existing SAM in situ. The latter approach is particularly advantageous to allow for diversity of surface functionalization from a single SAM and if the incorporation of bulky groups is desired. In the present study an organocatalytic isothiourea-mediated Michael addition-lactonization process analogous to a previously reported study in solution is presented. An achiral isothiourea, 3,4-dihydro-2H-pyrimido[2,1-b]benzothiazole (DHPB), promotes the intermolecular Michael addition-lactonization of a trifluoromethylenone terminated SAM and a variety of arylacetic acids affording C(6)-trifluoromethyldihydropyranones tethered to the surface. X-ray photoelectron spectroscopy, atomic force microscopy, contact angle, and ellipsometry analysis were conducted to confirm the presence of the substituted dihydropyranone. A model study of this approach was also performed in solution to probe the reaction diastereoselectivity as it cannot be measured directly on the surface. PMID:27015037

  20. 78 FR 3024 - Sam D. Hamilton Noxubee National Wildlife Refuge, MS; Intent To Prepare a Comprehensive...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-15

    ... Fish and Wildlife Service Sam D. Hamilton Noxubee National Wildlife Refuge, MS; Intent To Prepare a... conservation plan (CCP) and associated National Environmental Policy Act (NEPA) documents for Sam D. Hamilton... information to: Mr. Steve Reagan, Project Leader, Sam D. Hamilton Noxubee NWR, 2970 Bluff Lake...

  1. Chemoenzymatic synthesis and utilization of a SAM analog with an isomorphic nucleobase.

    PubMed

    Vranken, C; Fin, A; Tufar, P; Hofkens, J; Burkart, M D; Tor, Y

    2016-07-14

    SalL, an enzyme that catalyzes the synthesis of SAM from l-methionine and 5'-chloro-5'-deoxyoadenosine, is shown to accept 5'-chloro-5'-deoxythienoadenosine as a substrate and facilitate the synthesis of a synthetic SAM analog with an unnatural nucleobase. This synthetic cofactor is demonstrated to replace SAM in the DNA methylation reaction with M.TaqI. PMID:27270873

  2. Synergy between selection for production and longevity and the use of extended lactation: insights from a resource allocation model in a dairy goat herd.

    PubMed

    Douhard, F; Tichit, M; Amer, P R; Friggens, N C

    2014-11-01

    Although most of the genetic progress in production efficiency is achieved through selection at a global scale, locally, farm managers can also influence the selection process to better match genotypes and their varying herd environment. This study focused on the influence of a particular management decision--the use of extended lactation (EL) in dairy goat production systems--as it affects the survival and reproduction rates at the herd level, which may then shape different long-term selection responses. The objective was to understand and quantify the influences of EL and variability in achieved intake level on the responses to selection for production, reproduction, and longevity. An animal model of resource allocation between life functions was applied to the dairy goat. It predicts the trajectory of change in the herd genetic composition as affected by the feeding level and the selection pressure applied by the manager. During 40 yr, goats were selected for milk yield, reproduction, and, with a different selection weight for age (WAGE), for longevity. Under varying achieved intake levels, increasing WAGE improved the survival rate but a nonlinear effect was observed for the average milk yield and BCS. When moderately increasing WAGE from 0, resources were reallocated from lactation towards body reserves and survival, which led to a trade-off at the herd level between improving survival and BCS and increasing milk yield. When further increasing WAGE, old females became systematically preferred regardless of their reproductive status and the proportion of EL in the herd increased. Females undergoing EL had reduced energetic costs of reproduction, which improved their probability of survival. Across generations, an increased herd incidence of EL led to a relaxation of the selection pressure on the resource allocation to body reserves, which is normally imposed by the manager's priority to achieve successful reproduction at each mating. As selection for longevity

  3. [Preliminary study on autoregulation of samR involved in development and differentiation of Streptomyces ansochromogenes].

    PubMed

    Yang, Yan-ling; Yang, Hai-hua; Tan, Hua-rong

    2005-02-01

    The previous result showed that samR plays an important role in the development progress of Streptomyces ansochromogenes. It was reported that the differentiation progress of S. ansochromogenes was accelerated by a recombinant plasmid containing an extra copy of samR gene. However, the differentiation progress of S. ansochromogenes was not further accelerated by a multicopy plasmid containing samR gene. Electrophoresis mobility shift assay (EMSA) demonstrated that SamR binds to its own promoter region specifically. All these results hint that samR is an autoregulatory gene in Streptomyces ansochromogenes. PMID:15847153

  4. SAM Technical Review Committee Final Report: Summary and Key Recommendations from the Onsite TRC Meeting Held April 22-23, 2013

    SciTech Connect

    Blair, N.; Dobos, S.; Janzou, S.; Gilman, P.; Freeman, J.; Kaffine, L.

    2013-08-01

    The System Advisor Model (SAM) is a broad and robust set of models and frameworks for analyzing both system performance and system financing. It does this across a range of technologies dominated by solar technologies including photovoltaics (PV) and concentrated solar power (CSP). The U.S. Department of Energy (DOE) Solar Energy Technology Program requested the SAM development team to review the photovoltaic performance modeling with the development community and specifically, with the independent engineering community. The report summarizes the major effort for this technical review committee (TRC).

  5. A Model of the Regulation of Nitrogenase Electron Allocation in Legume Nodules (II. Comparison of Empirical and Theoretical Studies in Soybean).

    PubMed Central

    Moloney, A. H.; Guy, R. D.; Layzell, D. B.

    1994-01-01

    In N2-fixing legumes, the proportion of total electron flow through nitrogenase (total nitrogenase activity, TNA) that is used for N2 fixation is called the electron allocation coefficient (EAC). Previous studies have proposed that EAC is regulated by the competitive inhibition of H2 on N2 fixation and that the degree of H2 inhibition can be affected by a nodule's permeability to gas diffusion. To test this hypothesis, EAC was measured in soybean (Glycine max L. Merr.) nodules exposed to various partial pressures of H2 and N2, with or without changes in TNA or nodule permeability to gas diffusion, and the results were compared with the predictions of a mathematical model that combined equations for gas diffusion and competitive inhibition of N2 fixation (A. Moloney and D.B. Layzell [1993] Plant Physiol 103: 421-428). The empirical data clearly showed that decreases in EAC were associated with increases in external pH2, decreases in external pN2, and decreases in nodule permeability to O2 diffusion. The model predicted similar trends in EAC, and the small deviations that occurred between measured and predicted values could be readily accounted for by altering one or more of the following model assumptions: K1(H2) of nitrogenase (range from 2-4% H2), Km(N2) of nitrogenase (range from 4-5% N2), the allocation of less than 100% of whole-nodule respiration to tissues within the diffusion barrier, and the presence of a diffusion pathway that is open pore versus closed pore. The differences in the open-pore and closed-pore versions of the model suggest that it may be possible to use EAC measurements as a tool for the study of legume nodule diffusion barrier structure and function. The ability of the model to predict EAC provided strong support for the hypothesis that H2 inhibition of N2 fixation plays a major role in the in vivo control of EAC and that the presence of a variable barrier to gas diffusion affects the H2 and N2 concentration in the infected cell and

  6. Summary Status of the Space Acceleration Measurement System (SAMS), September 1993

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard

    1994-01-01

    The Space Acceleration Measurement System (SAMS) was developed to measure the microgravity acceleration environment to which NASA science payloads are exposed during microgravity science missions on the shuttle. Six flight units have been fabricated to date. The inaugural flight of a SAMS unit was on STS-40 in June 1991 as part of the First Spacelab Life Sciences mission. Since that time, SAMS has flown on six additional missions and gathered eighteen gigabytes of data representing sixty-eight days of microgravity environment. The SAMS units have been flown in the shuttle middeck and cargo bay, in the Spacelab module, and in the Spacehab module. This paper summarizes the missions and experiments which SAMS has supported. The quantity of data and the utilization of the SAMS data is described. Future activities are briefly described for the SAMS project and the Microgravity Measurement and Analysis project (MMAP) to support science experiments and scientists with microgravity environment measurement and analysis.

  7. First use of SAM onboard calibration gas cell

    NASA Astrophysics Data System (ADS)

    Malespin, C.; Trainer, M. G.; Manning, H. L.; Franz, H. B.; Conrad, P. G.; Raaen, E.; Webster, C. R.; Flesch, G.; Eigenbrode, J. L.; Wong, M. H.; Mahaffy, P. R.

    2015-12-01

    The Sample Analysis at Mars (SAM) instrument (Mahaffy et al 2012) suite on Curiosity completed its first measurement of the onboard calibration gas cell on MSL Mission Sol 1042. The cell consists of a gas mixture of four primary gases, along with trace fluorinated hydrocarbon high mass calibrants. The mix is comprised of approximately 25% CO2, N2, Xe and Ar, where the 129Xe has been given a three times enrichment relative to terrestrial xenon in order to distinguish it isotopically from Martian atmospheric Xe. Analysis of the calibration cell is intended to identify changes in instrument performance between pre-launch calibrations and operations on Mars, for any of the three main subsystems in SAM: the Quadrupole Mass Spectrometer (QMS), Tunable Laser Spectrometer (TLS), and Gas Chromatograph (GC). Here we present the experimental approach, results, and implications for instrument performance after almost three years of measurements on Mars.

  8. AstroNomical Information System at CeSAM

    NASA Astrophysics Data System (ADS)

    Gimenez, S.; Moreau, C.; Agneray, F.; Roehlly, Y.

    2014-05-01

    AstroNomical Information System (ANIS), developed by the Centre de donnéeS Astrophysique de Marseille (CeSAM), is a generic tool aimed at facilitating and homogenizing the implementation of astronomical data of various kinds and in dedicated Information Systems. ANIS provides high level services like: search, extract and display imaging and spectroscopic data using a combination of criteria, an object list, a sql query module or a cone search interfaces, as well as download of catalogs and complete datasets. With ANIS, the CeSAM offers web access to VO compliant Information Systems for different projects VVDS, HeDAM, ExoDat, HST-COSMOS, etc.), including ancillary data that are cross-matched before ingestion.

  9. TNF-α produced by SEC2 mutant (SAM-3)-activated human T cells induces apoptosis of HepG2 cells.

    PubMed

    Zhang, Guojun; Xu, Mingkai; Song, Yubo; Su, Zhencheng; Zhang, Huiwen; Zhang, Chenggang

    2016-03-01

    Staphylococcal enterotoxins C2 (SEC2) is a classical model of superantigens (SAg), which has the powerful ability to activate T cells as well as induce massive cytokine production. This property makes SEC2 and its mutants well concerned as a potential new immune-regulatory agent for cancer therapy. We previously constructed a SEC2 mutant named SAM-3, which had prominently antitumor activity in BALB/c mice model. But, the underlying molecular mechanism for stimulation of human peripheral blood mononuclear cells (PBMCs) and antitumor effect on human tumor cells induced by SAM-3 is not clear. Here, we showed that SAM-3 could activate human TCR Vβ 12, 13A, 14, 15, 17, and 20 CD8(+) subgroup T cells, which secreted the cytokines IL-2, IFN-γ, and TNF-α, and exhibit stimulation activity in a dose-dependent manner. TNF-α secreted from activated T cells could induce apoptosis and G1-phase arrest and lead to the antitumor effect in HepG2 cells. Meanwhile, SAM-3 upregulated the expression of tumor necrosis factor receptor 1 (TNFR1) mRNA and activity of caspase-3 and caspase-8. We also found that the antitumor activity and activity of caspase-3 and caspase-8 were decreased when the neutralizing TNF-α monoclonal antibody presented. These data suggest that TNF-α secreted by SAM-3-activated T cells is an important factor in inducing apoptosis in HepG2 cells. PMID:26536876

  10. Thiostrepton tryptophan methyltransferase expands the chemistry of radical SAM enzymes.

    PubMed

    Pierre, Stéphane; Guillot, Alain; Benjdia, Alhosna; Sandström, Corine; Langella, Philippe; Berteau, Olivier

    2012-12-01

    Methylation is among the most widespread chemical modifications encountered in biomolecules and has a pivotal role in many major biological processes. In the biosynthetic pathway of the antibiotic thiostrepton A, we identified what is to our knowledge the first tryptophan methyltransferase. We show that it uses unprecedented chemistry to methylate inactivated sp(2)-hybridized carbon atoms, despite being predicted to be a radical SAM enzyme. PMID:23064318

  11. GLAO4ELT: trade study and SAM experience

    NASA Astrophysics Data System (ADS)

    Tokovinin, A.

    2011-09-01

    It is expected that a large fraction of wave-front distortions at ELTs will be anisoplanatic, being produced jointly by near-ground and dome turbulence, wind buffeting, flexures, and vibrations. We compare various strategies for sensing this "ground" component using (i) several sodium LGSs, (ii) one or several Rayleigh LGSs and (ii) NGSs in a wide field. The experience gained so far with the RLGS GLAO system SAM at 4-m telescope will be presented and discussed.

  12. A sub-canopy structure for simulating oil palm in the Community Land Model (CLM-Palm): phenology, allocation and yield

    NASA Astrophysics Data System (ADS)

    Fan, Y.; Roupsard, O.; Bernoux, M.; Le Maire, G.; Panferov, O.; Kotowska, M. M.; Knohl, A.

    2015-11-01

    In order to quantify the effects of forests to oil palm conversion occurring in the tropics on land-atmosphere carbon, water and energy fluxes, we develop a new perennial crop sub-model CLM-Palm for simulating a palm plant functional type (PFT) within the framework of the Community Land Model (CLM4.5). CLM-Palm is tested here on oil palm only but is meant of generic interest for other palm crops (e.g., coconut). The oil palm has monopodial morphology and sequential phenology of around 40 stacked phytomers, each carrying a large leaf and a fruit bunch, forming a multilayer canopy. A sub-canopy phenological and physiological parameterization is thus introduced so that each phytomer has its own prognostic leaf growth and fruit yield capacity but with shared stem and root components. Phenology and carbon and nitrogen allocation operate on the different phytomers in parallel but at unsynchronized steps, separated by a thermal period. An important phenological phase is identified for the oil palm - the storage growth period of bud and "spear" leaves which are photosynthetically inactive before expansion. Agricultural practices such as transplanting, fertilization and leaf pruning are represented. Parameters introduced for the oil palm were calibrated and validated with field measurements of leaf area index (LAI), yield and net primary production (NPP) from Sumatra, Indonesia. In calibration with a mature oil palm plantation, the cumulative yields from 2005 to 2014 matched notably well between simulation and observation (mean percentage error = 3 %). Simulated inter-annual dynamics of PFT-level and phytomer-level LAI were both within the range of field measurements. Validation from eight independent oil palm sites shows the ability of the model to adequately predict the average leaf growth and fruit yield across sites and sufficiently represent the significant nitrogen- and age-related site-to-site variability in NPP and yield. Results also indicate that seasonal dynamics

  13. Mechanistic Enzymology of the Radical SAM Enzyme DesII

    PubMed Central

    2016-01-01

    DesII is a member of the radical SAM family of enzymes that catalyzes radical-mediated transformations of TDP-4-amino-4,6-didexoy-D-glucose as well as other sugar nucleotide diphosphates. Like nearly all radical SAM enzymes, the reactions begin with the reductive homolysis of SAM to produce a 5′-deoxyadenosyl radical which is followed by regiospecific hydrogen atom abstraction from the substrate. What happens next, however, depends on the nature of the substrate radical so produced. In the case of the biosynthetically relevant substrate, a radical-mediated deamination ensues; however, when this amino group is replaced with a hydroxyl, one instead observes dehydrogenation. The factors that govern the fate of the initially generated substrate radical as well as the mechanistic details underlying these transformations have been a key focus of research into the chemistry of DesII. This review will discuss recent discoveries pertaining to the enzymology of DesII, how it may relate to understanding other radical-mediated lyases and dehydrogenases and the working hypotheses currently being investigated regarding the mechanism of DesII catalysis.

  14. CE-SAM: a conversational interface for ISR mission support

    NASA Astrophysics Data System (ADS)

    Pizzocaro, Diego; Parizas, Christos; Preece, Alun; Braines, Dave; Mott, David; Bakdash, Jonathan Z.

    2013-05-01

    There is considerable interest in natural language conversational interfaces. These allow for complex user interactions with systems, such as fulfilling information requirements in dynamic environments, without requiring extensive training or a technical background (e.g. in formal query languages or schemas). To leverage the advantages of conversational interactions we propose CE-SAM (Controlled English Sensor Assignment to Missions), a system that guides users through refining and satisfying their information needs in the context of Intelligence, Surveillance, and Reconnaissance (ISR) operations. The rapidly-increasing availability of sensing assets and other information sources poses substantial challenges to effective ISR resource management. In a coalition context, the problem is even more complex, because assets may be "owned" by different partners. We show how CE-SAM allows a user to refine and relate their ISR information needs to pre-existing concepts in an ISR knowledge base, via conversational interaction implemented on a tablet device. The knowledge base is represented using Controlled English (CE) - a form of controlled natural language that is both human-readable and machine processable (i.e. can be used to implement automated reasoning). Users interact with the CE-SAM conversational interface using natural language, which the system converts to CE for feeding-back to the user for confirmation (e.g. to reduce misunderstanding). We show that this process not only allows users to access the assets that can support their mission needs, but also assists them in extending the CE knowledge base with new concepts.

  15. SAMS Acceleration Measurements on Mir (NASA Increment 4)

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard

    1998-01-01

    During NASA Increment 4 (January to May 1997), about 5 gigabytes of acceleration data were collected by the Space Acceleration Measurements System (SAMS) onboard the Russian Space Station, Mir. The data were recorded on 28 optical disks which were returned to Earth on STS-84. During this increment, SAMS data were collected in the Priroda module to support the Mir Structural Dynamics Experiment (MiSDE), the Binary Colloidal Alloy Tests (BCAT), Angular Liquid Bridge (ALB), Candle Flames in Microgravity (CFM), Diffusion Controlled Apparatus Module (DCAM), Enhanced Dynamic Load Sensors (EDLS), Forced Flow Flame Spreading Test (FFFr), Liquid Metal Diffusion (LMD), Protein Crystal Growth in Dewar (PCG/Dewar), Queen's University Experiments in Liquid Diffusion (QUELD), and Technical Evaluation of MIM (TEM). This report points out some of the salient features of the microgravity environment to which these experiments were exposed. Also documented are mission events of interest such as the docked phase of STS-84 operations, a Progress engine bum, Soyuz vehicle docking and undocking, and Progress vehicle docking. This report presents an overview of the SAMS acceleration measurements recorded by 10 Hz and 100 Hz sensor heads. The analyses included herein complement those presented in previous summary reports prepared by the Principal Investigator Microgravity Services (PIMS) group.

  16. Fair Water Allocation in Complex International River Systems

    NASA Astrophysics Data System (ADS)

    Beck, L.; Bernauer, T.

    2011-12-01

    Conflicts over water allocation in international freshwater systems are recurring phenomena, and climatic changes are likely to make existing problems worse in many parts of the world. Science-based proposals for water allocation frequently focus on allocating water to the economically most efficient purposes. In reality, allocation outcomes are often shaped by political and economic power, rather than considerations of economic efficiency. This paper develops a new approach to fair international water allocation in complex international freshwater systems. This approach covers both needs-based criteria - if acute water scarcity is present - and criteria for fair water allocation pertaining to relative gains in water-abundant situations. The usefulness of the approach is illustrated with a case study on the Zambezi River Basin (ZRB). Based on a hydrological model, and scenarios for water availability and demand in the ZRB until 2050, the paper shows how the waters of the ZRB could be allocated in a way that fairly distributes costs and benefits.

  17. Latent IBP Compound Dirichlet Allocation.

    PubMed

    Archambeau, Cedric; Lakshminarayanan, Balaji; Bouchard, Guillaume

    2015-02-01

    We introduce the four-parameter IBP compound Dirichlet process (ICDP), a stochastic process that generates sparse non-negative vectors with potentially an unbounded number of entries. If we repeatedly sample from the ICDP we can generate sparse matrices with an infinite number of columns and power-law characteristics. We apply the four-parameter ICDP to sparse nonparametric topic modelling to account for the very large number of topics present in large text corpora and the power-law distribution of the vocabulary of natural languages. The model, which we call latent IBP compound Dirichlet allocation (LIDA), allows for power-law distributions, both, in the number of topics summarising the documents and in the number of words defining each topic. It can be interpreted as a sparse variant of the hierarchical Pitman-Yor process when applied to topic modelling. We derive an efficient and simple collapsed Gibbs sampler closely related to the collapsed Gibbs sampler of latent Dirichlet allocation (LDA), making the model applicable in a wide range of domains. Our nonparametric Bayesian topic model compares favourably to the widely used hierarchical Dirichlet process and its heavy tailed version, the hierarchical Pitman-Yor process, on benchmark corpora. Experiments demonstrate that accounting for the power-distribution of real data is beneficial and that sparsity provides more interpretable results. PMID:26353244

  18. In situ analysis of martian regolith with the SAM experiment during the first mars year of the MSL mission: Identification of organic molecules by gas chromatography from laboratory measurements

    NASA Astrophysics Data System (ADS)

    Millan, M.; Szopa, C.; Buch, A.; Coll, P.; Glavin, D. P.; Freissinet, C.; Navarro-Gonzalez, R.; François, P.; Coscia, D.; Bonnet, J. Y.; Teinturier, S.; Cabane, M.; Mahaffy, P. R.

    2016-09-01

    The Sample Analysis at Mars (SAM) instrument onboard the Curiosity rover, is specifically designed for in situ molecular and isotopic analyses of martian surface materials and atmosphere. It contributes to the Mars Science Laboratory (MSL) missions primary scientific goal to characterize the potential past, present or future habitability of Mars. In all of the analyses of solid samples delivered to SAM so far, chlorinated organic compounds have been detected above instrument background levels and identified by gas chromatography coupled to mass spectrometry (GC-MS) (Freissinet et al., 2015; Glavin et al., 2013). While some of these may originate from reactions between oxychlorines and terrestrial organic carbon present in the instrument background (Glavin et al., 2013), others have been demonstrated to originate from indigenous organic carbon present in samples (Freissinet et al., 2015). We present here laboratory calibrations that focused on the analyses performed with the MXT-CLP GC column (SAM GC-5 channel) used for nearly all of the GC-MS analyses of the martian soil samples carried out with SAM to date. Complementary to the mass spectrometric data, gas chromatography allows us to separate and identify the species analyzable in a nominal SAM-GC run time of about 21 min. To characterize the analytical capabilities of this channel within the SAM Flight Model (FM) operating conditions on Mars, and their implications on the detection of organic matter, it is required to perform laboratory experimental tests and calibrations on spare model components. This work assesses the SAM flight GC-5 column efficiency, confirms the identification of the molecules based on their retention time, and enables a better understanding of the behavior of the SAM injection trap (IT) and its release of organic molecules. This work will enable further optimization of the SAM-GC runs for additional samples to be analyzed during the MSL mission.

  19. Modeling The Hydrology And Water Allocation Under Climate Change In Rural River Basins: A Case Study From Nam Ngum River Basin, Laos

    NASA Astrophysics Data System (ADS)

    Jayasekera, D. L.; Kaluarachchi, J.; Kim, U.

    2011-12-01

    estimated using the corrected GCM and baseline scenarios for future time periods of 2011-2050 and 2051-2090. A network based hydrologic and water resources model, WEAP, was used to simulate the current water allocation and management practices to identify the impacts of climate change in the 20th century. The results of this work are used to identify the multiple challenges faced by stakeholders and planners in water allocation for competing demands in the presence of climate change impacts.

  20. The SAMS: Smartphone Addiction Management System and verification.

    PubMed

    Lee, Heyoung; Ahn, Heejune; Choi, Samwook; Choi, Wanbok

    2014-01-01

    While the popularity of smartphones has given enormous convenience to our lives, their pathological use has created a new mental health concern among the community. Hence, intensive research is being conducted on the etiology and treatment of the condition. However, the traditional clinical approach based surveys and interviews has serious limitations: health professionals cannot perform continual assessment and intervention for the affected group and the subjectivity of assessment is questionable. To cope with these limitations, a comprehensive ICT (Information and Communications Technology) system called SAMS (Smartphone Addiction Management System) is developed for objective assessment and intervention. The SAMS system consists of an Android smartphone application and a web application server. The SAMS client monitors the user's application usage together with GPS location and Internet access location, and transmits the data to the SAMS server. The SAMS server stores the usage data and performs key statistical data analysis and usage intervention according to the clinicians' decision. To verify the reliability and efficacy of the developed system, a comparison study with survey-based screening with the K-SAS (Korean Smartphone Addiction Scale) as well as self-field trials is performed. The comparison study is done using usage data from 14 users who are 19 to 50 year old adults that left at least 1 week usage logs and completed the survey questionnaires. The field trial fully verified the accuracy of the time, location, and Internet access information in the usage measurement and the reliability of the system operation over more than 2 weeks. The comparison study showed that daily use count has a strong correlation with K-SAS scores, whereas daily use times do not strongly correlate for potentially addicted users. The correlation coefficients of count and times with total K-SAS score are CC = 0.62 and CC =0.07, respectively, and the t-test analysis for the

  1. Biomass Resource Allocation among Competing End Uses

    SciTech Connect

    Newes, E.; Bush, B.; Inman, D.; Lin, Y.; Mai, T.; Martinez, A.; Mulcahy, D.; Short, W.; Simpkins, T.; Uriarte, C.; Peck, C.

    2012-05-01

    The Biomass Scenario Model (BSM) is a system dynamics model developed by the U.S. Department of Energy as a tool to better understand the interaction of complex policies and their potential effects on the biofuels industry in the United States. However, it does not currently have the capability to account for allocation of biomass resources among the various end uses, which limits its utilization in analysis of policies that target biomass uses outside the biofuels industry. This report provides a more holistic understanding of the dynamics surrounding the allocation of biomass among uses that include traditional use, wood pellet exports, bio-based products and bioproducts, biopower, and biofuels by (1) highlighting the methods used in existing models' treatments of competition for biomass resources; (2) identifying coverage and gaps in industry data regarding the competing end uses; and (3) exploring options for developing models of biomass allocation that could be integrated with the BSM to actively exchange and incorporate relevant information.

  2. The Improvement of SAM Accumulation by Integrating the Endogenous Methionine Adenosyltransferase Gene SAM2 in Genome of the Industrial Saccharomyces cerevisiae Strain.

    PubMed

    Zhao, Weijun; Shi, Feng; Hang, Baojian; Huang, Lei; Cai, Jin; Xu, Zhinan

    2016-03-01

    S-Adenosyl-L-methionine (SAM) plays important roles in trans-methylation, trans-sulfuration, and polyamine synthesis in all living cells, and it is also an effective cure for liver disease, depressive syndromes, and osteoarthritis. The increased demands of SAM in pharmaceuticals industry have aroused lots of attempts to improve its production. In this study, a multiple-copy integrative plasmid pYMIKP-SAM2 was introduced into the chromosome of wild-type Saccharomyces cerevisiae strain ZJU001 to construct the recombined strain R1-ZJU001. Further studies showed that the recombinant yeast exhibited higher enzymatic activity of methionine adenosyltransferase and improved its SAM biosynthesis. With a three-phase fed-batch strategy in 15-liter bench-top fermentor, 8.81 g/L SAM was achieved after 52 h cultivation of R1-ZJU001, about 27.1 % increase over its parent strain ZJU001, whereas the SAM content was also improved from 64.6 mg/g DCW to 91.0 mg/g DCW. Our results shall provide insights into the metabolic engineering of SAM pathway in yeast for improved productivity of SAM and subsequent industrial applications. PMID:26728652

  3. Tree Biomass Allocation and Its Model Additivity for Casuarina equisetifolia in a Tropical Forest of Hainan Island, China

    PubMed Central

    Xue, Yang; Yang, Zhongyang; Wang, Xiaoyan; Lin, Zhipan; Li, Dunxi; Su, Shaofeng

    2016-01-01

    Casuarina equisetifolia is commonly planted and used in the construction of coastal shelterbelt protection in Hainan Island. Thus, it is critical to accurately estimate the tree biomass of Casuarina equisetifolia L. for forest managers to evaluate the biomass stock in Hainan. The data for this work consisted of 72 trees, which were divided into three age groups: young forest, middle-aged forest, and mature forest. The proportion of biomass from the trunk significantly increased with age (P<0.05). However, the biomass of the branch and leaf decreased, and the biomass of the root did not change. To test whether the crown radius (CR) can improve biomass estimates of C. equisetifolia, we introduced CR into the biomass models. Here, six models were used to estimate the biomass of each component, including the trunk, the branch, the leaf, and the root. In each group, we selected one model among these six models for each component. The results showed that including the CR greatly improved the model performance and reduced the error, especially for the young and mature forests. In addition, to ensure biomass additivity, the selected equation for each component was fitted as a system of equations using seemingly unrelated regression (SUR). The SUR method not only gave efficient and accurate estimates but also achieved the logical additivity. The results in this study provide a robust estimation of tree biomass components and total biomass over three groups of C. equisetifolia. PMID:27002822

  4. [Senescence-accelerated mouse (SAM): with special reference to age-associated pathologies and their modulation].

    PubMed

    Takeda, T

    1996-07-01

    The senescence-accelerated mouse (SAM) has been under development by our research team at Kyoto University since 1970 through selective inbreeding of the AKR/J strain of mice donated by the Jackson Laboratory in 1968, based on the data of the grading score of senescence, life span, and pathologic phenotypes. At present, there are 12 lines of SAM; the 9 senescence-prone inbred strains (SAMP) include SAMP1, SAMP2, SAMP3, SAMP6, SAMP7, SAMP8, SAMP9, SAMP10 and SAMP11, and the 3 senescence-resistant inbred strains (SAMR) SAMR1, SANR4 and SAMR5. Data from survival curves, the Gompertzian function and the grading score of senescence, together with growth patterns of body weight of these SAMP and SAMR mice revealed that the characteristic feature of aging common to all SAMP mice is "accelerated senescence": early onset and irreversible advance of senescence manifested by several signs and gross lesions such as the loss of normal behavior, various skin lesions, increased lordokyphosis, etc., after a period of normal development. Routine postmortem examinations and the pathobiological features revealed by systematically designed studies have shown several pathologic phenotypes, which are often characteristic enough to differentiate among the various SAM strains: senile amyloidosis in SAMP1, -P2, -P7, -P9, -P10 and -P11, secondary amyloidosis in SAMP2 and -P6, contracted kidney in SAMP1, -P2, -P10, -P11, immunoblastic lymphoma in SAMR1 and -R4, histiocytic sarcoma in SAMR1 and -R4, ovarian cysts in SAMR1, impaired immune response in SAMP1, -P2 and -P8, hyperinflation of the lungs in SAMP1, hearing impairment in SAMP1, degenerative temporomandibular joint disease in SAMP3, senile osteoporosis in SAMP6, deficits in learning and memory in SAMP8 and -P10, emotional disorders in SAMP8 and -P10, cataracts in SAMP9, and brain atrophy in SAMP10. These are all age-associated pathologies, the incidence and severity of which increase with advancing age. The SAM model in which these

  5. Unliganded EphA3 dimerization promoted by the SAM domain

    PubMed Central

    Singh, Deo R.; Cao, QingQing; King, Christopher; Salotto, Matt; Ahmed, Fozia; Zhou, Xiang Yang; Pasquale, Elena B.; Hristova, Kalina

    2015-01-01

    The erythropoietin-producing hepatocellular carcinoma A3 (EphA3) receptor tyrosine kinase (RTK) regulates morphogenesis during development and is overexpressed and mutated in a variety of cancers. EphA3 activation is believed to follow a ‘seeding mechanism’ model, in which ligand binding to the monomeric receptor acts as a trigger for signal-productive receptor clustering. We study EphA3 lateral interactions on the surface of live cells and we demonstrate that EphA3 forms dimers in the absence of ligand binding. We further show that these dimers are stabilized by interactions involving the EphA3 sterile α-motif (SAM) domain. The discovery of unliganded EphA3 dimers challenges the current understanding of the chain of EphA3 activation events and suggests that EphA3 may follow the ‘pre-formed dimer’ model of activation known to be relevant for other receptor tyrosine kinases. The present work also establishes a new role for the SAM domain in promoting Eph receptor lateral interactions and signalling on the cell surface. PMID:26232493

  6. Advances in liver transplantation allocation systems

    PubMed Central

    Schilsky, Michael L; Moini, Maryam

    2016-01-01

    With the growing number of patients in need of liver transplantation, there is a need for adopting new and modifying existing allocation policies that prioritize patients for liver transplantation. Policy should ensure fair allocation that is reproducible and strongly predictive of best pre and post transplant outcomes while taking into account the natural history of the potential recipients liver disease and its complications. There is wide acceptance for allocation policies based on urgency in which the sickest patients on the waiting list with the highest risk of mortality receive priority. Model for end-stage liver disease and Child-Turcotte-Pugh scoring system, the two most universally applicable systems are used in urgency-based prioritization. However, other factors must be considered to achieve optimal allocation. Factors affecting pre-transplant patient survival and the quality of the donor organ also affect outcome. The optimal system should have allocation prioritization that accounts for both urgency and transplant outcome. We reviewed past and current liver allocation systems with the aim of generating further discussion about improvement of current policies. PMID:26973389

  7. Advances in liver transplantation allocation systems.

    PubMed

    Schilsky, Michael L; Moini, Maryam

    2016-03-14

    With the growing number of patients in need of liver transplantation, there is a need for adopting new and modifying existing allocation policies that prioritize patients for liver transplantation. Policy should ensure fair allocation that is reproducible and strongly predictive of best pre and post transplant outcomes while taking into account the natural history of the potential recipients liver disease and its complications. There is wide acceptance for allocation policies based on urgency in which the sickest patients on the waiting list with the highest risk of mortality receive priority. Model for end-stage liver disease and Child-Turcotte-Pugh scoring system, the two most universally applicable systems are used in urgency-based prioritization. However, other factors must be considered to achieve optimal allocation. Factors affecting pre-transplant patient survival and the quality of the donor organ also affect outcome. The optimal system should have allocation prioritization that accounts for both urgency and transplant outcome. We reviewed past and current liver allocation systems with the aim of generating further discussion about improvement of current policies. PMID:26973389

  8. Systematic biochemical characterization of the SAM domains in Eph receptor family from Mus Musculus.

    PubMed

    Wang, Yue; Li, Qingxia; Zheng, Yunhua; Li, Gang; Liu, Wei

    2016-05-13

    The Eph receptor family is the largest subfamily of receptor tyrosine kinases and well-known for their pivotal roles in axon guidance, synaptogenesis, artery/venous differentiation and tumorigenesis, etc. Activation of the Eph receptor needs multimerization of the receptors. The intracellular C-terminal SAM domain of Eph receptor was reported to mediate self-association of Eph receptors via the homo SAM-SAM interaction. In this study, we systematically expressed and purified the SAM domain proteins of all fourteen Eph receptors of Mus musculus in Escherichia coli. The FPLC (fast protein liquid chromatography) results showed the recombinant SAM domains were highly homogeneous. Using CD (circular dichroism) spectrometry, we found that the secondary structure of all the SAM domains was typically alpha helical folded and remarkably similar. The thermo-stability tests showed that they were quite stable in solution. SEC-MALS (size exclusion chromatography coupled with multiple angle light scattering) results illustrated 200 μM Eph SAM domains behaved as good monomers in the size-exclusion chromatography. More importantly, DLS (dynamic light scattering) results revealed the overwhelming majority of SAM domains was not multimerized in solution either at 200 μM or 2000 μM protein concentration, which indicating the SAM domain alone was not sufficient to mediate the polymerization of Eph receptor. In summary, our studies provided the systematic biochemical characterizations of the Eph receptor SAM domains and implied their roles in Eph receptor mediated signaling pathways. PMID:27086853

  9. Spectrum allocations above 40 GHz

    NASA Technical Reports Server (NTRS)

    Katzenstein, W. E.; Moore, R. P.; Kimball, H. G.

    1981-01-01

    The 1979 World Administrative Radio Conference (WARC-79) revised the International Table of Frequency Allocations to reflect increased interest and activity in the region of the EM spectrum above 40 GHz. The total width of the spectrum allocated (235 GHz) in the region above 40 GHz indicates the extent of this new spectrum resource, made accessible by advances in the state-of-the-art of telecommunications equipment. There are some striking differences between the approach to allocation above and below 40 GHz. For example, there are not bands allocated exclusively. This reflects the characteristics of propagation and the small antenna beamwidths achievable at these frequencies. Attention is given to atmospheric window and absorption band limits, allocations to satellite services, allocations to scientific services, allocations to terrestrial services, the future refinement of the radio regulations above 40 GHz, and allocations of WARC-79 and frequency management.

  10. RESOURCES ALLOCATION TO OPTIMIZE MINING POLLUTION CONTROL

    EPA Science Inventory

    A comprehensive model for mine drainage simulation and optimization of resource allocation to control mine acid pollution in a watershed has been developed. The model is capable of: (a) Producing a time trace of acid load and flow from acid drainage sources as a function of clima...

  11. Investigation and incorporation of water inflow uncertainties through stochastic modelling in a combined optimisation methodology for water allocation in Alfeios River (Greece)

    NASA Astrophysics Data System (ADS)

    Bekri, Eleni; Yannopoulos, Panayotis; Disse, Markus

    2014-05-01

    The Alfeios River plays a vital role for Western Peloponnisos in Greece from natural, ecological, social and economic aspect. The main river and its six tributaries, forming the longest watercourse and the highest streamflow rate of Peloponnisose, represent a significant source of water supply for the region, aiming at delivering and satisfying the expected demands from a variety of water users, including irrigation, drinking water supply, hydropower production and recreation. In the previous EGU General Assembly, a fuzzy-boundary-interval linear programming methodology, based on Li et al. (2010) and Bekri et al. (2012), has been presented for optimal water allocation under uncertain and vague system conditions in the Alfeios River Basin. Uncertainties associated with the benefit and cost coefficient in the objective function of the main water uses (hydropower production and irrigation) were expressed as probability distributions and fuzzy boundary intervals derived by associated α-cut levels. The uncertainty of the monthly water inflows was not incorporated in the previous initial application and the analysis of all other sources of uncertainty has been applied to two extreme hydrologic years represented by a selected wet and dry year. To manage and operate the river system, decision makers should be able to analyze and evaluate the impact of various hydrologic scenarios. In the present work, the critical uncertain parameter of water inflows is analyzed and its incorporation as an additional type of uncertainty in the suggested methodology is investigated, in order to enable the assessment of optimal water allocation for hydrologic and socio-economic scenarios based both on historical data and projected climate change conditions. For this purpose, stochastic simulation analysis for a part of the Alfeios river system is undertaken, testing various stochastic models from simple stationary ones (AR and ARMA), Thomas-Fiering, ARIMA as well as more sophisticated and

  12. Economics of spectrum allocation

    NASA Astrophysics Data System (ADS)

    Melody, W. H.

    The effective and efficient allocation and use of the spectrum can be ensured only by a set of sharing rules that will reflect the interests, values, and power of all affected parties. What is now happening is that the new interests and different values of the developing countries are pressing to change the international sharing rules established by a small group of high-technology nations. It is noted that the latter have established a massive telecommunications infrastructure on the basis of inherited sharing rules that reflect only their interests and a much simplified scarcity problem. Once long-term goals and underlying principles of allocation are established, communication technologies and markets can be directed, through a series of adjustment policies, to achieve them. A crucial first step in the creation of an international information environment in which 'free' flows will be balanced flows is the establishment of a balanced and equitable set of sharing rules for the radio spectrum.

  13. Benchmark Simulations of the Thermal-Hydraulic Responses during EBR-II Inherent Safety Tests using SAM

    SciTech Connect

    Hu, Rui; Sumner, Tyler S.

    2016-01-01

    An advanced system analysis tool SAM is being developed for fast-running, improved-fidelity, and wholeplant transient analyses at Argonne National Laboratory under DOE-NE’s Nuclear Energy Advanced Modeling and Simulation (NEAMS) program. As an important part of code development, companion validation activities are being conducted to ensure the performance and validity of the SAM code. This paper presents the benchmark simulations of two EBR-II tests, SHRT-45R and BOP- 302R, whose data are available through the support of DOE-NE’s Advanced Reactor Technology (ART) program. The code predictions of major primary coolant system parameter are compared with the test results. Additionally, the SAS4A/SASSYS-1 code simulation results are also included for a code-to-code comparison.

  14. Detection of Nitric Oxide by the Sample Analysis at Mars (SAM) Instrument Implications for the Presence of Nitrates

    NASA Technical Reports Server (NTRS)

    Navarro-Gonzalez, R.; Stern, J.; Freissinet, C.; Franz, H. B.; Eigenbrode, J. L..; McKay, C. P.; Coll, P.; Sutter, B.; Archer, D.; McAdam, A.; Cabane, M.; Ming, D. W.; Glavin, D.; Leshin, L.; Wong, M.; Atreya, S.; Wray, J. J.; Steele, A.; Buch, A.; Prats, B. D.; Szopa, C.; Coscia, D.; Teinturier, S.; Conrad, P.; Owen, T. C.; Mahaffy, P.; Grotzinger, J. P.

    2014-01-01

    One of the main goals of the Mars Science Laboratory is to determine whether the planet ever had environmental conditions able to support microbial life. Nitrogen is a fundamental element for life, and is present in structural (e.g., proteins), catalytic (e.g., enzymes and ribozymes), energy transfer (e.g., ATP) and information storage (RNA and DNA) biomolecules. Planetary models suggest that molecular nitrogen was abundant in the early Martian atmosphere, but was rapidly lost to space by photochemistry, sputtering impact erosion, and oxidized and deposited to the surface as nitrate. Nitrates are a fundamental source for nitrogen to terrestrial microorganisms. Therefore, the detection of nitrates in soils and rocks is important to assess the habitability of a Martian environment. SAM is capable of detecting nitrates by their thermal decomposition into nitric oxide, NO. Here we analyze the release of NO from soils and rocks examined by the SAM instrument at Gale crater, and discuss its origin.

  15. Shear-Induced Detachment of Polystyrene Beads from SAM-Coated Surfaces.

    PubMed

    Cho, Kwun Lun; Rosenhahn, Axel; Thelen, Richard; Grunze, Michael; Lobban, Matthew; Karahka, Markus Leopold; Kreuzer, H Jürgen

    2015-10-13

    In this work we experimentally and theoretically analyze the detachment of microscopic polystyrene beads from different self-assembled monolayer (SAM) surfaces in a shear flow in order to develop a mechanistic model for the removal of cells from surfaces. The detachment of the beads from the surface is treated as a thermally activated process applying an Arrhenius Ansatz to determine the activation barrier and attempt frequency of the rate determing step in bead removal. The statistical analysis of the experimental shear detachment data obtained in phosphate-buffered saline buffer results in an activation energy around 20 kJ/mol, which is orders of magnitude lower than the adhesion energy measured by atomic force microscopy (AFM). The same order of magnitude for the adhesion energy measured by AFM is derived from ab initio calculations of the van der Waals interaction energy between the polystyrene beads and the SAM-covered gold surface. We conclude that the rate determing step for detachment of the beads is the initiation of rolling on the surface (overcoming static friction) and not physical detachment, i.e., lifting the particle off the surface. PMID:26401759

  16. A fuzzy multi-objective model for capacity allocation and pricing policy of provider in data communication service with different QoS levels

    NASA Astrophysics Data System (ADS)

    Pan, Wei; Wang, Xianjia; Zhong, Yong-guang; Yu, Lean; Jie, Cao; Ran, Lun; Qiao, Han; Wang, Shouyang; Xu, Xianhao

    2012-06-01

    Data communication service has an important influence on e-commerce. The key challenge for the users is, ultimately, to select a suitable provider. However, in this article, we do not focus on this aspect but the viewpoint and decision-making of providers for order allocation and pricing policy when orders exceed service capacity. It is a multiple criteria decision-making problem such as profit and cancellation ratio. Meanwhile, we know realistic situations in which much of the input information is uncertain. Thus, it becomes very complex in a real-life environment. In this situation, fuzzy sets theory is the best tool for solving this problem. Our fuzzy model is formulated in such a way as to simultaneously consider the imprecision of information, price sensitive demand, stochastic variables, cancellation fee and the general membership function. For solving the problem, a new fuzzy programming is developed. Finally, a numerical example is presented to illustrate the proposed method. The results show that it is effective for determining the suitable order set and pricing policy of provider in data communication service with different quality of service (QoS) levels.

  17. GENERATING SOPHISTICATED SPATIAL SURROGATES USING THE MIMS SPATIAL ALLOCATOR

    EPA Science Inventory

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

  18. Myrmics Memory Allocator

    2011-09-23

    MMA is a stand-alone memory management system for MPI clusters. It implements a shared Partitioned Global Address Space, where multiple MPI processes request objects from the allocator and the latter provides them with system-wide unique memory addresses for each object. It provides applications with an intuitive way of managing the memory system in a unified way, thus enabling easier writing of irregular application code.

  19. Non-canonical active site architecture of the radical SAM thiamin pyrimidine synthase

    SciTech Connect

    Fenwick, Michael K.; Mehta, Angad P.; Zhang, Yang; Abdelwahed, Sameh H.; Begley, Tadhg P.; Ealick, Steven E.

    2015-03-27

    Radical S-adenosylmethionine (SAM) enzymes use a [4Fe-4S] cluster to generate a 5'-deoxyadenosyl radical. Canonical radical SAM enzymes are characterized by a β-barrel-like fold and SAM anchors to the differentiated iron of the cluster, which is located near the amino terminus and within the β-barrel, through its amino and carboxylate groups. Here we show that ThiC, the thiamin pyrimidine synthase in plants and bacteria, contains a tethered cluster-binding domain at its carboxy terminus that moves in and out of the active site during catalysis. In contrast to canonical radical SAM enzymes, we predict that SAM anchors to an additional active site metal through its amino and carboxylate groups. Superimposition of the catalytic domains of ThiC and glutamate mutase shows that these two enzymes share similar active site architectures, thus providing strong evidence for an evolutionary link between the radical SAM and adenosylcobalamin-dependent enzyme superfamilies.

  20. Attention allocation before antisaccades.

    PubMed

    Klapetek, Anna; Jonikaitis, Donatas; Deubel, Heiner

    2016-01-01

    In the present study, we investigated the distribution of attention before antisaccades. We used a dual task paradigm, in which participants made prosaccades or antisaccades and discriminated the orientation of a visual probe shown at the saccade goal, the visual cue location (antisaccade condition), or a neutral location. Moreover, participants indicated whether they had made a correct antisaccade or an erroneous prosaccade. We observed that, while spatial attention in the prosaccade task was allocated only to the saccade goal, attention in the antisaccade task was allocated both to the cued location and to the antisaccade goal. This suggests parallel attentional selection of the cued and antisaccade locations. We further observed that in error trials--in which participants made an incorrect prosaccade instead of an antisaccade--spatial attention was biased towards the prosaccade goal. These erroneous prosaccades were mostly unnoticed and were often followed by corrective antisaccades with very short latencies (<100 ms). Data from error trials therefore provide further evidence for the parallel programming of the reflexive prosaccade to the cue and the antisaccade to the intended location. Taken together, our results suggest that attention allocation and saccade goal selection in the antisaccade task are mediated by a common competitive process. PMID:26790843

  1. GABAergic inhibition shapes SAM responses in rat auditory thalamus.

    PubMed

    Cai, R; Caspary, D M

    2015-07-23

    Auditory thalamus (medial geniculate body [MGB]) receives ascending inhibitory GABAergic inputs from inferior colliculus (IC) and descending GABAergic projections from the thalamic reticular nucleus (TRN) with both inputs postulated to play a role in shaping temporal responses. Previous studies suggested that enhanced processing of temporally rich stimuli occurs at the level of MGB, with our recent study demonstrating enhanced GABA sensitivity in MGB compared to IC. The present study used sinusoidal amplitude-modulated (SAM) stimuli to generate modulation transfer functions (MTFs), to examine the role of GABAergic inhibition in shaping the response properties of MGB single units in anesthetized rats. Rate MTFs (rMTFs) were parsed into "bandpass (BP)", "mixed (Mixed)", "highpass (HP)" or "atypical" response types, with most units showing the Mixed response type. GABAA receptor blockade with iontophoretic application of the GABAA receptor (GABAAR) antagonist gabazine (GBZ) selectively altered the response properties of most MGB neurons examined. Mixed and HP units showed significant GABAAR-mediated SAM-evoked rate response changes at higher modulation frequencies (fms), which were also altered by N-methyl-d-aspartic acid (NMDA) receptor blockade (2R)-amino-5-phosphonopentanoate (AP5). BP units, and the lower arm of Mixed units responded to GABAAR blockade with increased responses to SAM stimuli at or near the rate best modulation frequency (rBMF). The ability of GABA circuits to shape responses at higher modulation frequencies is an emergent property of MGB units, not observed at lower levels of the auditory pathway and may reflect activation of MGB NMDA receptors (Rabang and Bartlett, 2011; Rabang et al., 2012). Together, GABAARs exert selective rate control over selected fms, generally without changing the units' response type. These results showed that coding of modulated stimuli at the level of auditory thalamus is at least, in part, strongly controlled by GABA

  2. Paramagnetic Intermediates Generated by Radical S-Adenosylmethionine (SAM) Enzymes

    PubMed Central

    2015-01-01

    Conspectus A [4Fe–4S]+ cluster reduces a bound S-adenosylmethionine (SAM) molecule, cleaving it into methionine and a 5′-deoxyadenosyl radical (5′-dA•). This step initiates the varied chemistry catalyzed by each of the so-called radical SAM enzymes. The strongly oxidizing 5′-dA• is quenched by abstracting a H-atom from a target species. In some cases, this species is an exogenous molecule of substrate, for example, l-tyrosine in the [FeFe] hydrogenase maturase, HydG. In other cases, the target is a proteinaceous residue as in all the glycyl radical forming enzymes. The generation of this initial radical species and the subsequent chemistry involving downstream radical intermediates is meticulously controlled by the enzyme so as to prevent unwanted reactions. But the manner in which this control is exerted is unknown. Electron paramagnetic resonance (EPR) spectroscopy has proven to be a valuable tool used to gain insight into these mechanisms. In this Account, we summarize efforts to trap such radical intermediates in radical SAM enzymes and highlight four examples in which EPR spectroscopic results have shed significant light on the corresponding mechanism. For lysine 2,3-aminomutase, nearly each possible intermediate, from an analogue of the initial 5′-dA• to the product radical l-β-lysine, has been explored. A paramagnetic intermediate observed in biotin synthase is shown to involve an auxiliary [FeS] cluster whose bridging sulfide is a co-substrate for the final step in the biosynthesis of vitamin B7. In HydG, the l-tyrosine substrate is converted in unprecedented fashion to a 4-oxidobenzyl radical on the way to generating CO and CN– ligands for the [FeFe] cluster of hydrogenase. And finally, EPR has confirmed a mechanistic proposal for the antibiotic resistance protein Cfr, which methylates the unactivated sp2-hybridized C8-carbon of an adenosine base of 23S ribosomal RNA. These four systems provide just a brief survey of the ever-growing set

  3. Uranium from phosphoric acid: IMC`s Uncle Sam Plant

    SciTech Connect

    1994-02-01

    This article discusses uranium recovery from phosphoric acid, proven to be a viable technology by several U.S. producers since 1978. This technology has accounted for 12.8% of U.S. uranium production during this time: a total of almost 40 Mlb equivalent U3O8. Of the several producers, only the Uncle Sam plant of IMC-Agrico has operated continuously during the period, and that plant is the longest-lived uranium production facility operating in the United States. The basis for the process is reviewed, including geological aspects, mining and recovery of phosphorite, phosphoric acid production, and uranium recovery. Licensing of such facilities is also discussed.

  4. Comparative studies of aerosol extinction measurements made by the SAM II and SAGE II satellite experiments

    NASA Technical Reports Server (NTRS)

    Yue, Glenn K.; Mccormick, M. P.; Chu, W. P.; Wang, P.; Osborn, M. T.

    1989-01-01

    Results from the Stratospheric Aerosol Measurement (SAM) II and Stratospheric Aerosol and Gas Experiment (SAGE) II are compared for measurement locations which are coincident in time and space. At 1.0 micron, the SAM II and SAGE II aerosol extinction profiles are similar within their measurement errors. In addition, sunrise and sunset aerosol extinction data at four different wavelengths are compared for occasions when the SAGE II and SAM II measurements are nearly coincident in space and about 12 hours apart.

  5. The nuclear protein Sam68 is cleaved by the FMDV 3C protease redistributing Sam68 to the cytoplasm during FMDV infection of host cells

    SciTech Connect

    Lawrence, Paul; Schafer, Elizabeth A.; Rieder, Elizabeth

    2012-03-30

    Picornavirus infection can lead to disruption of nuclear pore traffic, shut-off of cell translation machinery, and cleavage of proteins involved in cellular signal transduction and the innate response to infection. Here, we demonstrated that the FMDV 3C{sup pro} induced the cleavage of nuclear RNA-binding protein Sam68 C-terminus containing the nuclear localization sequence (NLS). Consequently, it stimulated the redistribution of Sam68 to the cytoplasm. The siRNA knockdown of Sam68 resulted in a 1000-fold reduction in viral titers, which prompted us to study the effect of Sam68 on FMDV post-entry events. Interestingly, Sam68 interacts with the internal ribosomal entry site within the 5 Prime non-translated region of the FMDV genome, and Sam68 knockdown decreased FMDV IRES-driven activity in vitro suggesting that it could modulate translation of the viral genome. The results uncover a novel role for Sam68 in the context of picornaviruses and the proteolysis of a new cellular target of the FMDV 3C{sup pro}.

  6. Synaptic Tagging During Memory Allocation

    PubMed Central

    Rogerson, Thomas; Cai, Denise; Frank, Adam; Sano, Yoshitake; Shobe, Justin; Aranda, Manuel L.; Silva, Alcino J.

    2014-01-01

    There is now compelling evidence that the allocation of memory to specific neurons (neuronal allocation) and synapses (synaptic allocation) in a neurocircuit is not random and that instead specific mechanisms, such as increases in neuronal excitability and synaptic tagging and capture, determine the exact sites where memories are stored. We propose an integrated view of these processes, such that neuronal allocation, synaptic tagging and capture, spine clustering and metaplasticity reflect related aspects of memory allocation mechanisms. Importantly, the properties of these mechanisms suggest a set of rules that profoundly affect how memories are stored and recalled. PMID:24496410

  7. 50 CFR 660.323 - Pacific whiting allocations, allocation attainment, and inseason allocation reapportionment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Pacific whiting allocations, allocation...) FISHERIES OFF WEST COAST STATES West Coast Groundfish Fisheries § 660.323 Pacific whiting allocations... amounts that will be harvested, or a combination of the two. Estimates of the amount of Pacific...

  8. The first year: Development of a LANDSAT capability at Sam Houston State University

    NASA Technical Reports Server (NTRS)

    Bounds, J. H.

    1981-01-01

    Problems encountered in initiating a LANDSAT data processing capability at Sam Houston State University are discussed. Computer requirements, financing, and academic and administrative support are addressed.

  9. Sam68 is cleaved by caspases under apoptotic cell death induced by ionizing radiation.

    PubMed

    Cho, Seong-Jun; Choi, Moo Hyun; Nam, Seon Young; Kim, Ji Young; Kim, Cha Soon; Pyo, Suhkneung; Yang, Kwang Hee

    2015-03-01

    The RNA-binding protein Sam68, a mitotic substrate of tyrosine kinases, has been reported to participate in the cell cycle, apoptosis, and signaling. In particular, overexpression of Sam68 protein is known to suppress cell growth and cell cycle progression in NIH3T3 cells. Although Sam68 is involved in many cellular activities, the function of Sam68, especially in response to apoptotic stimulation, is not well understood. In this study, we found that Sam68 protein is cleaved in immune cells undergoing apoptosis induced by γ-radiation. Moreover, we found that Sam68 cleavage was induced by apoptotic stimuli containing γ-radiation in a caspase-dependent manner. In particular, we showed that activated casepase-3, 7, 8 and 9 can directly cleave Sam68 protein through in vitro protease cleavage assay. Finally, we found that the knockdown of Sam68 attenuated γ-radiation-induced cell death and growth suppression. Conclusively, the cleavage of Sam68 is a new indicator for the cell damaging effects of ionizing radiation. PMID:25666188

  10. Dielectric behavior of the frog lens in the 100 Hz to 500 MHz range. Simulation with an allocated ellipsoidal-shells model.

    PubMed Central

    Watanabe, M; Suzaki, T; Irimajiri, A

    1991-01-01

    In an attempt to correlate the passive electrical properties of the lens tissue with its structure, we measured ac admittances for isolated frog lenses, lens nuclei, and homogenate of cortical fiber cells, over the frequency range 10(2)-5.10(8) Hz. The whole lenses molded into discoid shape show a characteristic "two-step" dielectric dispersion with a huge permittivity increment of the order of 10(5) at 1 kHz. Of the two subdispersions disclosed, dispersion 1 has a permittivity increment (delta epsilon) of 2.10(5) with a characteristic frequency (fc) of 2 kHz, and dispersion 2 has a delta epsilon of 400 with an fc of 2 MHz. In terms of loss tangent, these dispersions are more clearly located as two separate peaks. Data are analyzed using an allocated ellipsoidal-shells model which has been developed by taking into account fiber orientation inside the lens tissue. Dispersion 1 is assigned to the equatorial cortex, where fiber cells run parallel to the applied electric field, and dispersion 2 to the nucleus with a complex fiber arrangement and also to the polar cortex, in which the fiber alignment is predominantly perpendicular. In addition, the model analysis reveals that, in the frog lens, the nucleus occupies approximately 30% in volume and that relative permittivity and conductivity for the cell interior are, respectively, 45 and 3 mS/cm for the cortical cells, and 28 and 0.3 mS/cm for the nuclear cells. Images FIGURE 5 PMID:2015379

  11. Constrained Allocation Flux Balance Analysis.

    PubMed

    Mori, Matteo; Hwa, Terence; Martin, Olivier C; De Martino, Andrea; Marinari, Enzo

    2016-06-01

    New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an "ensemble averaging" procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferred at fast growth). In addition, CAFBA allows for quantitatively accurate predictions on the rate of acetate excretion and growth yield based on only 3 parameters determined by empirical growth laws. PMID:27355325

  12. Constrained Allocation Flux Balance Analysis

    PubMed Central

    Mori, Matteo; Hwa, Terence; Martin, Olivier C.

    2016-01-01

    New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an “ensemble averaging” procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferred at fast growth). In addition, CAFBA allows for quantitatively accurate predictions on the rate of acetate excretion and growth yield based on only 3 parameters determined by empirical growth laws. PMID:27355325

  13. Tertiary contacts control switching of the SAM-I riboswitch.

    PubMed

    Hennelly, Scott P; Sanbonmatsu, Karissa Y

    2011-03-01

    Riboswitches are non-coding RNAs that control gene expression by sensing small molecules through changes in secondary structure. While secondary structure and ligand interactions are thought to control switching, the exact mechanism of control is unknown. Using a novel two-piece assay that competes the anti-terminator against the aptamer, we directly monitor the process of switching. We find that the stabilization of key tertiary contacts controls both aptamer domain collapse and the switching of the SAM-I riboswitch from the aptamer to the expression platform conformation. Our experiments demonstrate that SAM binding induces structural alterations that indirectly stabilize the aptamer domain, preventing switching toward the expression platform conformer. These results, combined with a variety of structural probing experiments performed in this study, show that the collapse and stabilization of the aptamer domain are cooperative, relying on the sum of key tertiary contacts and the bimodal stability of the kink-turn motif for function. Here, ligand binding serves to shift the equilibrium of aptamer domain structures from a more open toward a more stable collapsed form by stabilizing tertiary interactions. Our data show that the thermodynamic landscape for riboswitch operation is finely balanced to allow large conformational rearrangements to be controlled by small molecule interactions. PMID:21097777

  14. Tertiary contacts control switching of the SAM-I riboswitch

    PubMed Central

    Hennelly, Scott P.; Sanbonmatsu, Karissa Y.

    2011-01-01

    Riboswitches are non-coding RNAs that control gene expression by sensing small molecules through changes in secondary structure. While secondary structure and ligand interactions are thought to control switching, the exact mechanism of control is unknown. Using a novel two-piece assay that competes the anti-terminator against the aptamer, we directly monitor the process of switching. We find that the stabilization of key tertiary contacts controls both aptamer domain collapse and the switching of the SAM-I riboswitch from the aptamer to the expression platform conformation. Our experiments demonstrate that SAM binding induces structural alterations that indirectly stabilize the aptamer domain, preventing switching toward the expression platform conformer. These results, combined with a variety of structural probing experiments performed in this study, show that the collapse and stabilization of the aptamer domain are cooperative, relying on the sum of key tertiary contacts and the bimodal stability of the kink-turn motif for function. Here, ligand binding serves to shift the equilibrium of aptamer domain structures from a more open toward a more stable collapsed form by stabilizing tertiary interactions. Our data show that the thermodynamic landscape for riboswitch operation is finely balanced to allow large conformational rearrangements to be controlled by small molecule interactions. PMID:21097777

  15. Redox regulation in shoot growth, SAM maintenance and flowering.

    PubMed

    Schippers, Jos Hm; Foyer, Christine H; van Dongen, Joost T

    2016-02-01

    Reactive oxygen species (ROS) and associated reduction/oxidation (redox) controls involving glutathione, glutaredoxins and thioredoxins play key roles in the regulation of plant growth and development. While many questions remain concerning redox functions in the shoot apical meristem (SAM), accumulating evidence suggests that redox master switches integrate major hormone signals and transcriptional networks in the SAM, and so regulate organ growth, polarity and floral development. Auxin-induced activation of plasma-membrane located NADPH-oxidases and mitochondrial respiratory bioenergetics are likely regulators of the ROS bursts that drive the cell cycle in proliferating regions, with other hormones such as jasmonic acid playing propagating or antagonistic roles in gene regulation. Moreover, the activation of oxygen production by photosynthesis and oxygen-dependent N-end rule controls are linked to the transition from cell proliferation to cell expansion and differentiation. While much remains to be understood, the nexus of available redox controls provides a key underpinning mechanism linking hormonal controls, energy metabolism and bioenergetics to plant growth and development. PMID:26799134

  16. Development of target allocation methods for LAMOST focal plate

    NASA Astrophysics Data System (ADS)

    Yuan, Hailong; Zhang, Haotong; Zhang, Yanxia; Lei, Yajuan; Dong, Yiqiao

    2014-01-01

    We first introduce the primary target allocation requirements and restrictions for the parallel control multiple fiber system, which is used in the LAMOST spectroscopic survey. The fiber positioner anti-collision model is imported. Then several target allocation methods and features are discussed in detail, including a network flow algorithm, high priority for fiber unit holding less target number, target allocation algorithm for groups, target allocation method for add-ons and target reallocation. Their virtues and weaknesses are analyzed for various kinds of scientific research situations. Furthermore an optimization concept using the Simulate Anneal Arithmetic (SAA) is developed to improve the fiber utilizing efficiency.

  17. Telescope Time Allocation Tool

    NASA Astrophysics Data System (ADS)

    Alves, J.

    2005-03-01

    TaToo is ESO's new Time Allocation Tool. This software scheduler is a combination of a user-friendly graphical user interface and an intelligent constraint-programming engine fine-tuned to ESO's scheduling problem. TaToo is able to produce a high quality and reliable schedule taking into consideration all constraints of the recommended programs for all telescopes in about 15 minutes. This performance allows schedulers at ESO-VISAS to simulate and evaluate different scenarios, optimize the scheduling of engineering activities at the observatories, and in the end construct the most science efficient schedule possible.

  18. [Organ allocation. Ethical issues].

    PubMed

    Cattorini, P

    2010-01-01

    The criteria for allocating organs are one of the most debated ethical issue in the transplantation programs. The article examines some rules and principles followed by "Nord Italia Transplant program", summarized in its Principles' Charter and explained in a recent interdisciplinary book. General theories of justice and their application to individual clinical cases are commented and evaluated, in order to foster a public, democratic, transparent debate among professionals and citizens, scientific associations and customers' organizations. Some specific moral dilemmas are focused regarding the concepts of proportionate treatment, unselfish donation by living persons, promotion of local institutions efficiency. PMID:20677677

  19. Allocation for the SANDAC multiprocessor system

    SciTech Connect

    Ravl, T.M.; Ercegovac, M.D.

    1986-01-01

    This report describes an algorithm for the static allocation of tasks in a general Dataflow Multiprocessor and the SANDAC IV system in particular. Initially a model of execution and the underlying assumptions about the architecture are outlined. The authors then discuss a Graph Reduction algorithm for preprocessing the computation graph. The Graph Reduction algorithm reduces a fine grain graph to an optimal grain graph. The heuristic allocation algorithm is presented and is based on giving precedence to critical paths and minimizing the communication time between tasks. The performance of the algorithm is analyzed and the effect of varying parameters is studied. Subsequently an alternative variation with better characteristics is proposed.

  20. Dynamic carbon allocation significantly changed land carbon sink and carbon pool sizes

    NASA Astrophysics Data System (ADS)

    Xia, J.; Yuan, W.

    2015-12-01

    The allocation of photosynthate among the plant components (e.g., leaves, stems, and roots) plays an important role in regulating plant growth, competition, and terrestrial carbon cycle. However, the carbon allocation process is still a weak part in the earth system models (ESMs). In this study, the Integrated BIosphere Simulator (IBIS) model coupled with a dynamic carbon allocation model (IBISAL) is used to explore the impact of carbon allocation on the terrestrial carbon cycle. This dynamic carbon allocation model suggests that plants should allocate the largest part of carbon to the plant components which need to capture the most limiting resources, such as light, water and nitrogen. In comparison to the results of original IBIS model using fixed allocation ratios, the net ecosystem productivity, global biomass and soil organic carbon simulated by IBISAL model decreased by13.4% , 9.9% and 20.8%, respectively . The dynamic allocation scheme tends to benefit roots allocation. Because roots had short turnover times, high roots allocation led to the decreases of global carbon sink and carbon pool sizes. The observations showed that the carbon allocation ratios changed with temperature and precipitation. The dynamic carbon allocation model could reproduce this phenomenon correctly. The results show that the dynamic carbon allocation ratios of boreal evergreen forests and C3 grasses are consistent well with the observations. However, the IBISAL, and another three ESMs (i.e., CESM1-BGC, IPSL-CM5A-MR and NorESM1-ME models) adopting dynamic allocation scheme overestimated the stems allocation of tropical forests. This study shows the substantial influences of carbon allocation on the carbon sink and carbon pool sizes. Therefore, improving estimations of carbon allocation by ESMs are an important and effective path to reduce uncertainties in the global carbon cycle simulation and climate change prediction.

  1. Task mapping for non-contiguous allocations.

    SciTech Connect

    Leung, Vitus Joseph; Bunde, David P.; Ebbers, Johnathan; Price, Nicholas W.; Swank, Matthew; Feer, Stefan P.; Rhodes, Zachary D.

    2013-02-01

    This paper examines task mapping algorithms for non-contiguously allocated parallel jobs. Several studies have shown that task placement affects job running time for both contiguously and non-contiguously allocated jobs. Traditionally, work on task mapping either uses a very general model where the job has an arbitrary communication pattern or assumes that jobs are allocated contiguously, making them completely isolated from each other. A middle ground between these two cases is the mapping problem for non-contiguous jobs having a specific communication pattern. We propose several task mapping algorithms for jobs with a stencil communication pattern and evaluate them using experiments and simulations. Our strategies improve the running time of a MiniApp by as much as 30% over a baseline strategy. Furthermore, this improvement increases markedly with the job size, demonstrating the importance of task mapping as systems grow toward exascale.

  2. In situ analysis of Mars soil sample with the sam gcms instrumentation onboard Curiosity : interpretation and comparison of measurements done at Rocknest and Yelloknife bay sites

    NASA Astrophysics Data System (ADS)

    Szopa, Cyril; Coll, Patrice; Cabane, Michel; Coscia, David; Buch, Arnaud; Francois, Pascaline; Millan, Maeva; Teinturier, Sammy; Navarro-Gonzales, Rafael; Glavin, Daniel; Freissinet, Caro; Steele, Andrew; Eigenbrode, Jen; Mahaffy, Paul

    2014-05-01

    The characterisation of the chemical and mineralogical composition of regolith samples collected with the Curiosity rover is a primary objective of the SAM experiment. These data should provide essential clues on the past habitability of Gale crater. Amongst the SAM suite of instruments [1], SAM-GC (Gas Chromatograph) is devoted to identify and quantify volatiles evolved from the thermal (heating up to about 900°C)/chemical (derivatization procedure) treatment of any soil sample collected by the Curiosity rover. With the aim to search for potential organic molecules outgassed from the samples, a SAM-GC analytical channel composed of thermal-desorption injector and a MXT-CLP chromatographic column was chosen to achieve all the measurements done up today, as it was designed for the separation of a wide range of volatile organic molecules. Three solid samples have been analyzed with GCMS, one sand sample collected at the Rocknest site, and two rock samples (John Klein and Cumberland respectively) collected at the Yellowknife Bay site using the Curiosity driller. All the measurements were successful and they produced complex chromatograms with both detectors used for SAM GC, i.e. a thermal conductivity detector and the SAM quandrupole mass spectrometer. Their interpretation already revealed the presence of an oxychlorine phase present in the sample which is at the origin of chlorohydrocarbons clearly identified [2] but this represents only a fraction of the GCMS signal recorded [3,4]. This work presents a systematic comparison of the GCMS measurements done for the different samples collected, supported by reference data obtained in laboratory with different spare models of the gas chromatograph, with the aim to bring new elements of interpretation of the SAM measurements. References: [1] Mahaffy, P. et al. (2012) Space Sci Rev, 170, 401-478. [2] Glavin, D. et al. (2013), JGR. [3] Leshin L. et al. (2013), Science, [4] Ming D. et al. (2013), Science, 32, 64

  3. Allocation of Human Resources for Collection Development.

    ERIC Educational Resources Information Center

    Bryant, Bonita

    1986-01-01

    This article reviews personnel administration techniques that have been used to establish work-load parameters, but offer no aid in subject deployment. A model which identifies elements that must be included in a consideration of work-load measurement and subject allocation for library collection development tasks is presented. Thirty-four…

  4. Computationally efficient control allocation

    NASA Technical Reports Server (NTRS)

    Durham, Wayne (Inventor)

    2001-01-01

    A computationally efficient method for calculating near-optimal solutions to the three-objective, linear control allocation problem is disclosed. The control allocation problem is that of distributing the effort of redundant control effectors to achieve some desired set of objectives. The problem is deemed linear if control effectiveness is affine with respect to the individual control effectors. The optimal solution is that which exploits the collective maximum capability of the effectors within their individual physical limits. Computational efficiency is measured by the number of floating-point operations required for solution. The method presented returned optimal solutions in more than 90% of the cases examined; non-optimal solutions returned by the method were typically much less than 1% different from optimal and the errors tended to become smaller than 0.01% as the number of controls was increased. The magnitude of the errors returned by the present method was much smaller than those that resulted from either pseudo inverse or cascaded generalized inverse solutions. The computational complexity of the method presented varied linearly with increasing numbers of controls; the number of required floating point operations increased from 5.5 i, to seven times faster than did the minimum-norm solution (the pseudoinverse), and at about the same rate as did the cascaded generalized inverse solution. The computational requirements of the method presented were much better than that of previously described facet-searching methods which increase in proportion to the square of the number of controls.

  5. The Use of Student Outcomes in Resource Allocation Decisions.

    ERIC Educational Resources Information Center

    Elfner, Eliot S.

    Resource allocation processes suitable for use in not-for-profit institutions are discussed and a conceptual model for resource allocation in institutions of higher education is presented. The objectives of higher education include the personal development and education of students, not merely the certification of students by conferring degrees.…

  6. On the Allocation of Resources for Secondary Schools

    ERIC Educational Resources Information Center

    Haelermans, Carla; De Witte, Kristof; Blank, Jos L. T.

    2012-01-01

    This paper studies the optimal allocation of resources--in terms of school management, teachers, supporting employees and materials--in secondary schools. We use a flexible budget constrained output distance function model to estimate both technical and allocative efficiency scores for 448 Dutch secondary schools between 2002 and 2007. The results…

  7. Sam68 Regulates S6K1 Alternative Splicing during Adipogenesis

    PubMed Central

    Song, Jingwen

    2015-01-01

    The requirement for alternative splicing during adipogenesis is poorly understood. The Sam68 RNA binding protein is a known regulator of alternative splicing, and mice deficient for Sam68 exhibit adipogenesis defects due to defective mTOR signaling. Sam68 null preadipocytes were monitored for alternative splicing imbalances in components of the mTOR signaling pathway. Herein, we report that Sam68 regulates isoform expression of the ribosomal S6 kinase gene (Rps6kb1). Sam68-deficient adipocytes express Rps6kb1-002 and its encoded p31S6K1 protein, in contrast to wild-type adipocytes that do not express this isoform. Sam68 binds an RNA sequence encoded by Rps6kb1 intron 6 and prevents serine/arginine-rich splicing factor 1 (SRSF1)-mediated alternative splicing of Rps6kb1-002, as assessed by cross-linking and immunoprecipitation (CLIP) and minigene assays. Depletion of p31S6K1 with small interfering RNAs (siRNAs) partially restored adipogenesis of Sam68-deficient preadipocytes. The ectopic expression of p31S6K1 in wild-type 3T3-L1 cells resulted in adipogenesis differentiation defects, showing that p31S6K1 is an inhibitor of adipogenesis. Our findings indicate that Sam68 is required to prevent the expression of p31S6K1 in adipocytes for adipogenesis to occur. PMID:25776557

  8. Regioselective patterning of multiple SAMs and applications in surface-guided smart microfluidics.

    PubMed

    Chen, Chuanzhao; Xu, Pengcheng; Li, Xinxin

    2014-12-24

    A top-down nanofabrication technology is developed to integrate multiple SAMs (self-assembled monolayers) into regioselective patterns. With ultraviolet light exposure through regioselectively hollowed hard mask, an existing SAM at designated microregions can be removed and a dissimilar kind of SAM can be regrown there. By repeating the photolithography-like process cycle, diverse kinds of SAM building blocks can be laid out as a desired pattern in one microfluidic channel. In order to ensure high quality of the surface modifications, the SAMs are vapor-phase deposited before the channel is closed by a bonding process. For the first time the technique makes it possible to integrate three or more kinds of SAMs in one microchannel. The technique is very useful for multiplex surface functionalization of microfluidic chips where different segments of a microfluidic channel need to be individually modified with different SAMs or into arrayed pattern for surface-guided fluidic properties like hydrophobicity/philicity and/or oleophobicity/philicity, etc. The technique has been well validated by experimental demonstration of various surface-directed flow-guiding functions. By modifying a microchannel surface into an arrayed pattern of multi-SAM "two-tone" stripe array, surface-guiding-induced 3D swirling flow is generated in a microfluidic channel that experimentally exhibits quick oil/water mixing and high-efficiency oil-to-water chemical extraction. PMID:25438296

  9. Overview of SAM results obtained at Gale Crater during the 180 first sols

    NASA Astrophysics Data System (ADS)

    Coll, P.; Mahaffy, P. R.; Cabane, M.; Webster, C. R.; Archer, D.; Atreya, S. K.; Benna, M.; Brinckerhoff, W. B.; Brunner, A.; Buch, A.; Conrad, P.; Coscia, D.; Dobson, N.; Dworkin, J.; Eigenbrode, J.; Farley, K.; Flesch, G.; Franz, H.; Freissinet, C.; Galvin, D.; Gorevan, S.; Harpold, D.; Hengemihle, J.; Jaeger, F.; Johnson, C.; Johnson, M.; Jones, J.; Lefavor, M.; Leshin, L.; Lyness, E.; Malespin, C.; Manning, H.; Martin, D.; McAdam, A.; McKay, C.; Miller, K.; Ming, D. W.; Morris, R. V.; Navarro-González, R.; Niles, P.; Nolan, T.; Owen, T.; Pavolv, A.; Prats, B.; Pepin, R.; Raaen, E.; Raulin, F.; Steele, A.; Stern, J.; Squyres, S.; Sutter, B.; Summons, R. E.; Szopa, C.; Tan, F.; Teinturier, S.; Trainer, M.; Wong, M.; Wray, J.

    2013-09-01

    During the first 180 sols of Curiosity's landed mission on Mars (8/6/2012 to 2/7/2013) SAM sampled the atmosphere more than a dozen times, the dusty sandpile named Rocknest and a basin site named John Klein on the floor of Gale crater. The atmospheric experiments utilized SAM's quadrupole mass spectrometer (QMS) and its tunable laser spectrometer (TLS) while the solid sample experiments also utilized the gas chromatograph (GC). Although a number of core experiments were pre-programmed and stored in SAM EEProm, the high level SAM scripting language enabled the team to often optimize experiments based on prior runs. SAM and its Experiment Sequences exercised during the First 120 Sols: The SAM instruments, its gas processing system (GPS) and its sample manipulation system (SMS) have been already described [1]. During the first few weeks of the landed mission SAM carried out a variety of instrument health checks and then began a series of atmospheric experiments to measure atmospheric composition and isotope ratios. From sol 56 to 102 Curiosity lingered at Rocknest to clean out the surfaces of the sample processing system by scooping several times into this fine grained material, vibrating to abrade possible contamination from surfaces, and then discarding before delivery of sample to SAM from the 5th scoop.

  10. 77 FR 19691 - Notice of Inventory Completion: Sam Noble Oklahoma Museum of Natural History, Norman, OK

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-02

    ... National Park Service Notice of Inventory Completion: Sam Noble Oklahoma Museum of Natural History, Norman... Natural History has completed an inventory of human remains and associated funerary objects, in... associated funerary objects may contact the Sam Noble Oklahoma Museum of Natural History. Repatriation of...

  11. Unanticipated coordination of tris buffer to the Radical SAM cluster of the RimO methylthiotransferase.

    PubMed

    Molle, Thibaut; Clémancey, Martin; Latour, Jean-Marc; Kathirvelu, Velavan; Sicoli, Giuseppe; Forouhar, Farhad; Mulliez, Etienne; Gambarelli, Serge; Atta, Mohamed

    2016-07-01

    Radical SAM enzymes generally contain a [4Fe-4S](2+/1+) (RS cluster) cluster bound to the protein via the three cysteines of a canonical motif CxxxCxxC. The non-cysteinyl iron is used to coordinate SAM via its amino-carboxylate moiety. The coordination-induced proximity between the cluster acting as an electron donor and the adenosyl-sulfonium bond of SAM allows for the homolytic cleavage of the latter leading to the formation of the reactive 5'-deoxyadenosyl radical used for substrate activation. Most of the structures of Radical SAM enzymes have been obtained in the presence of SAM, and therefore, little is known about the situation when SAM is not present. In this report, we show that RimO, a methylthiotransferase belonging to the radical SAM superfamily, binds a Tris molecule in the absence of SAM leading to specific spectroscopic signatures both in Mössbauer and pulsed EPR spectroscopies. These data provide a cautionary note for researchers who work with coordinative unsaturated iron sulfur clusters. PMID:27259294

  12. Winning Attitude & Dedication to Physical Therapy Keep Sam Schmidt on Track

    ERIC Educational Resources Information Center

    Bosley, Nikki Prevenslik

    2006-01-01

    This article relates how Sam Schmidt returned to living a productive life after an accident left him with spinal cord injury. Schmidt was a former Indy Racing League driver who founded Sam Schmidt Motorsports after his accident in 2000. Schmidt's car hit the wall as he exited turn two during a practice session at Walt Disney World Speedway in…

  13. Radical SAM catalysis via an organometallic intermediate with an Fe-[5'-C]-deoxyadenosyl bond.

    PubMed

    Horitani, Masaki; Shisler, Krista; Broderick, William E; Hutcheson, Rachel U; Duschene, Kaitlin S; Marts, Amy R; Hoffman, Brian M; Broderick, Joan B

    2016-05-13

    Radical S-adenosylmethionine (SAM) enzymes use a [4Fe-4S] cluster to cleave SAM to initiate diverse radical reactions. These reactions are thought to involve the 5'-deoxyadenosyl radical intermediate, which has not yet been detected. We used rapid freeze-quenching to trap a catalytically competent intermediate in the reaction catalyzed by the radical SAM enzyme pyruvate formate-lyase activating enzyme. Characterization of the intermediate by electron paramagnetic resonance and (13)C, (57)Fe electron nuclear double-resonance spectroscopies reveals that it contains an organometallic center in which the 5' carbon of a SAM-derived deoxyadenosyl moiety forms a bond with the unique iron site of the [4Fe-4S] cluster. Discovery of this intermediate extends the list of enzymatic bioorganometallic centers to the radical SAM enzymes, the largest enzyme superfamily known, and reveals intriguing parallels to B12 radical enzymes. PMID:27174986

  14. Function Allocation in Complex Socio-Technical Systems: Procedure usage in nuclear power and the Context Analysis Method for Identifying Design Solutions (CAMIDS) Model

    NASA Astrophysics Data System (ADS)

    Schmitt, Kara Anne

    This research aims to prove that strict adherence to procedures and rigid compliance to process in the US Nuclear Industry may not prevent incidents or increase safety. According to the Institute of Nuclear Power Operations, the nuclear power industry has seen a recent rise in events, and this research claims that a contributing factor to this rise is organizational, cultural, and based on peoples overreliance on procedures and policy. Understanding the proper balance of function allocation, automation and human decision-making is imperative to creating a nuclear power plant that is safe, efficient, and reliable. This research claims that new generations of operators are less engaged and thinking because they have been instructed to follow procedures to a fault. According to operators, they were once to know the plant and its interrelations, but organizationally more importance is now put on following procedure and policy. Literature reviews were performed, experts were questioned, and a model for context analysis was developed. The Context Analysis Method for Identifying Design Solutions (CAMIDS) Model was created, verified and validated through both peer review and application in real world scenarios in active nuclear power plant simulators. These experiments supported the claim that strict adherence and rigid compliance to procedures may not increase safety by studying the industry's propensity for following incorrect procedures, and when it directly affects the outcome of safety or security of the plant. The findings of this research indicate that the younger generations of operators rely highly on procedures, and the organizational pressures of required compliance to procedures may lead to incidents within the plant because operators feel pressured into following the rules and policy above performing the correct actions in a timely manner. The findings support computer based procedures, efficient alarm systems, and skill of the craft matrices. The solution to

  15. S.A.M., the Italian Martian Simulation Chamber

    NASA Astrophysics Data System (ADS)

    Galletta, G.; Ferri, F.; Fanti, G.; D'Alessandro, M.; Bertoloni, G.; Pavarin, D.; Bettanini, C.; Cozza, P.; Pretto, P.; Bianchini, G.; Debei, S.

    2006-12-01

    The Martian Environment Simulator (SAM “Simulatore di Ambiente Marziano”) is a interdisciplinary project of Astrobiology done at University of Padua. The research is aimed to the study of the survival of the microorganisms exposed to the “extreme” planetary environment. The facility has been designed in order to simulate Mars’ environmental conditions in terms of atmospheric pressure, temperature cycles and UV radiation dose. The bacterial cells, contained into dedicated capsules, will be exposed to thermal cycles simulating diurnal and seasonal Martian cycles. The metabolism of the different biological samples will be analysed at different phases of the experiment, to study their survival and eventual activity of protein synthesis (mortality, mutations and capability of DNA reparing). We describe the experimental facility and provide the perspectives of the biological experiments we will perform in order to provide hints on the possibility of life on Mars either autochthonous or imported from Earth.

  16. Presentation on a Space Acceleration Measurement System (SAMS)

    NASA Technical Reports Server (NTRS)

    Chase, Theodore L.

    1990-01-01

    The primary objective of the Space Acceleration Measurement Systems (SAMS) project is to provide an acceleration measurement system capable of serving a wide variety of space experiments. The design of the system being developed under this project takes into consideration requirements for experiments located in the middeck, in the orbiter bay, and in Spacelab. In addition to measuring, conditioning, and recording accelerations, the system will be capable of performing complex calculations and interactive control. The main components consist of a remote triaxial optical storage device. In operation, the triaxial sensor head produces output signals in response to acceleration inputs. These signals are preamplified, filtered and converted into digital data which is then transferred to optical memory. The system design is modular, facilitating both software and hardware upgrading as technology advances. Two complete acceleration measurement flight systems will be build and tested under this project.

  17. Research on allocation efficiency of the daisy chain allocation algorithm

    NASA Astrophysics Data System (ADS)

    Shi, Jingping; Zhang, Weiguo

    2013-03-01

    With the improvement of the aircraft performance in reliability, maneuverability and survivability, the number of the control effectors increases a lot. How to distribute the three-axis moments into the control surfaces reasonably becomes an important problem. Daisy chain method is simple and easy to be carried out in the design of the allocation system. But it can not solve the allocation problem for entire attainable moment subset. For the lateral-directional allocation problem, the allocation efficiency of the daisy chain can be directly measured by the area of its subset of attainable moments. Because of the non-linear allocation characteristic, the subset of attainable moments of daisy-chain method is a complex non-convex polygon, and it is difficult to solve directly. By analyzing the two-dimensional allocation problems with a "micro-element" idea, a numerical calculation algorithm is proposed to compute the area of the non-convex polygon. In order to improve the allocation efficiency of the algorithm, a genetic algorithm with the allocation efficiency chosen as the fitness function is proposed to find the best pseudo-inverse matrix.

  18. Photon multiplication in wide-gap BAM and SAM aluminates

    NASA Astrophysics Data System (ADS)

    Lushchik, Aleksandr; Lushchik, Cheslav; Feldbach, Eduard; Kudryavtseva, Irina; Liblik, Peeter; Maaroos, Aarne; Nagirnyi, Vitali; Savikhin, Fjodor; Vasil'chenko, Eugeni

    2005-08-01

    Processes of various intrinsic and impurity luminescence excitation by 4-32 eV photons or 18 and 300 keV electrons have been studied in pure and doped BaMgAl10O17 (BAM) and SrMgAl10O17 (SAM) phosphors at 6-300 K. In BAM:Eu (l0%), the quantum yield of Eu2+ center emission is QY = 1 in the region of exciting photon energies of hνec = 7-12 eV, the value of QY reaches 2 at 14-21 eV and sharply increases at hνec = 22-32 eV, where secondary electron-hole pairs are created by hot conduction electrons. The processes connected with the rise of QY for various types of emission in the region of 14-21 eV have been thoroughly studied for BAM and SAM phosphors. It has been suggested that such exciting photons cause the ionization of oxygen ions and form hot valence holes, the energy of which is partially used for the excitation of Eu2+ ions (4f7→4f65d1 transitions) due to nonradiative Auger transitions. The intensity of the Eu2+ emission increases after a single nanosecond electron pulse with a rise time of 50-150 ns. This rise is connected with the energy transfer from spinel blocks to Eu2+ ions located at cation planes of the β-alumina-type materials.

  19. Social activity method (SAM): A fractal language for mathematics

    NASA Astrophysics Data System (ADS)

    Dowling, Paul

    2013-09-01

    In this paper I shall present and develop my organisational language, social activity method (SAM), and illustrate some of its applications. I shall introduce a new scheme for modes of recontextualisation that enables the analysis of the ways in which one activity - which might be school mathematics or social research or any empirically observed regularity of practice - recontextualises the practice of another and I shall also present, deploy, and develop an existing scheme - domains of action - in an analysis of school mathematics examination papers and in the structuring of what I refer to as the esoteric domain. This domain is here conceived as a hybrid domain of, first, linguistic and extralinguistic resources that are unambiguously mathematical in terms of both expression and content and, second, pedagogic theory - often tacit - that enables the mathematical gaze onto other practices and so recontextualises them. A second and more general theme that runs through the paper is the claim that there is nothing that is beyond semiosis, that there is nothing to which we have direct access, unmediated by interpretation. This state of affairs has implications for mathematics education. Specifically, insofar as an individual's mathematical semiotic system is under continuous development - the curriculum never being graspable all at once - understanding - as a stable semiotic moment - of any aspect or object of mathematics is always localised to the individual and is at best transient, and the sequencing of such moments may well also be more individualised than consistent in some correspondence with the sequencing of the curriculum. This being the case, a concentration on understanding as a goal may well serve to inhibit the pragmatic acquisition and deployment of mathematical technologies, which should be the principal aim of mathematics teaching and learning. The paper is primarily concerned with mathematics education. SAM, however, is a language that is available for

  20. Nonlinear Optical Studies of Self-Assembled Monolayers (SAM) Silica-SAM-Water Interface Probed With Second Harmonic Generation

    NASA Astrophysics Data System (ADS)

    James, Kenneth

    2010-03-01

    Second harmonic generation (SHG) is a successful and widely used technique for the study of surfaces and surface phenomena. We present a novel technique using second harmonic generation from oriented water molecules in the Gouy-Chapman diffuse layer at the alkylsiloxane and biomolecular self assembled monolayer (SAM) interface with water to measure distance between the solid surface and the average location of the oriented water in the diffuse layer. Distances of one nanometer can be distinguished. This in situ probe is applicable for organic adsorbates which in general will push the diffuse layer away from the solid surface. The organic layer thickness can be used to obtain the adsorption fraction. From this and an understanding of the likely chemistry, the orientation of the molecules can be inferred. We have demonstrated this technique on three molecular systems: hydrophobic self assembled monolayers of methoxysilane molecules of varying hydrocarbon chain length, self assembled monolayers of streptavidin glycoproteins and the combined streptavidin-biotinylated antibody monolayer.

  1. Streptomyces serine protease (SAM-P20): recombinant production, characterization, and interaction with endogenous protease inhibitor.

    PubMed Central

    Taguchi, S; Suzuki, M; Kojima, S; Miura, K; Momose, H

    1995-01-01

    Previously, we isolated a candidate for an endogenous target enzyme(s) of the Streptomyces subtilisin inhibitor (SSI), termed SAM-P20, from a non-SSI-producing mutant strain (S. Taguchi, A. Odaka, Y. Watanabe, and H. Momose, Appl. Environ. Microbiol. 61:180-186, 1995). In this study, in order to investigate the detailed enzymatic properties of this protease, an overproduction system of recombinant SAM-P20 was established in Streptomyces coelicolor with the SSI gene promoter. The recombinant SAM-P20 was purified by salting out and by two successive ion-exchange chromatographies to give a homogeneous band by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Partial peptide mapping and amino acid composition analysis revealed that the recombinant SAM-P20 was identical to natural SAM-P20. From the results for substrate specificity and inhibitor sensitivity, SAM-P20 could be categorized as a chymotrypsin-like protease with an arginine-cleavable activity, i.e., a serine protease with broad substrate specificity. For proteolytic activity, the optimal pH was 10.0 and the optimal temperature was shifted from 50 to 80 degrees C by the addition of 10 mM calcium ion. The strong stoichiometric inhibition of SAM-P20 activity by SSI dimer protein occurred in a subunit molar ratio of these two proteins of about 1, and an inhibitor constant of SSI toward SAM-P20 was estimated to be 8.0 x 10(-10) M. The complex formation of SAM-P20 and SSI was monitored by analytical gel filtration, and a complex composed of two molecules of SAM-P20 and one dimer molecule of SSI was detected, in addition to a complex of one molecule of SAM-P20 bound to one dimer molecule of SSI. The reactive site of SSI toward SAM-P20 was identified as Met-73-Val-74 by sequence analysis of the modified form of SSI, which was produced by the acidification of the complex of SSI and SAM-P20. This reactive site is the same that toward an exogenous target enzyme, subtilisin BPN'. PMID:7592444

  2. MSL/SAM Measurements of Volatile Isotopes, and their Implications for Atmospheric Loss

    NASA Astrophysics Data System (ADS)

    Atreya, Sushil K.; Mahaffy, Paul; Webster, Christopher; Wong, Michael; Conrad, Pamela; Franz, Heather; Grotzinger, John; Jones, John; Leshin, Laurie; Malespin, Charles; Manning, Heidi; Navarro-Gonzalez, Raphael; Owen, Tobias; Pepin, Robert; Schwenzer, Susanne; Trainer, Melissa

    2014-05-01

    High precision measurements of the isotopes of carbon and oxygen in CO2, hydrogen in H2O, nitrogen in N2, and argon in the martian atmosphere have been made by the Sample Analysis at Mars (SAM) instrument on the Curiosity Rover [1,2,3,4]. The resulting values in per mil are 46 for δ13C (relative to VPDB reference standard), 48 for δ18O (VSMOW), 5880 for δD (VSMOW), 572 for δ15N (relative to earth atmosphere), and 4.2 for 36Ar/38Ar (or δ38Ar=310 relative to sun reference standard). The observed enrichment of the heavier isotope over the lighter isotope means that loss to space rather than loss to the surface dominates the isotopic composition in the martian atmosphere. Vertical mixing transports the volatiles from the surface up to the upper atmosphere. While eddy diffusion and molecular diffusion control the distribution of the noble gases, photochemistry also plays a significant role in the distribution of the other volatiles as they diffuse to the upper atmosphere. The above SAM data on the isotopic ratios of carbon, oxygen, hydrogen, nitrogen and argon implies a massive loss of the atmosphere from Mars in the past four billion years. Only hydrogen (hence water) is likely to escape thermally due to the low exospheric temperature of Mars. However, the lack of intrinsic magnetic field on Mars allows solar wind to interact directly with the atmosphere, thus opening up a myriad of possibilities for escape of volatiles from Mars. One such mechanism studied by the ion mass analyzer instrument on Mars Express finds that at current rate of erosion by solar wind, Mars may have lost between 0.2 and 4 millibar of the CO2 atmosphere in the past 3.5 billion years [5]. However, these authors [5] stress that other mechanisms including photochemical, sputtering and cold plasma escape may result in up to 1000 times greater rate of atmospheric loss based on models. Any fractionation in the isotopes of the heavy noble gas, xenon, would have occurred prior to approximately 4 Ga

  3. The nuclear protein Sam68 is recruited to the cytoplasmic stress granules during enterovirus 71 infection.

    PubMed

    Zhang, Hua; Chen, Ning; Li, Pengfei; Pan, Ziye; Ding, Yun; Zou, Dehua; Li, Liyang; Xiao, Lijie; Shen, Binglei; Liu, Shuxia; Cao, Hongwei; Cui, Yudong

    2016-07-01

    Our previous study found that the nuclear protein, 68-kDa Src-associated in mitosis protein (Sam68), is translocated to the cytoplasm and forms punctate pattern during enterovirus 71 (EV71) infection [Virus Research, 180 (2014), 1-11]. However, the exact function of this punctate pattern in cytoplasm during EV71 infection remains unknown. In this study, we firstly have examined this punctate pattern of Sam68 re-localization in the cytoplasm, and observed the obvious recruitments of Sam68 to the EV71-induced stress granules (SGs). Sam68, belongs to the KH domain family of RNA binding proteins (RBPs), was then confirmed that its KH domain was essential for this recruitment. Nevertheless, Knockdown of Sam68 expression using ShRNA had no effects on SGs assembly, indicating that Sam68 is not a constitutive component of the SGs during EV71 infection. Lastly, we investigated the importance of microtubulin transport to SGs aggregation, and revealed that microtubule depolymerization inhibited SGs formation, suggesting that EV71-induced SGs move throughout the cytoplasm in a microtubule-dependent manner. Taken together, these results illuminated that EV71 infections can induce SGs formation, and Sam68, as a SGs component, migrates alone with SGs dependent on intact microtubule upon the viral infections. These findings may provide novel underlying mechanism for delineating the role of SGs during EV71 infection. PMID:27057671

  4. SAMS Acceleration Measurements on Mir from November 1995 to March 1996

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard

    1997-01-01

    The NASA Microgravity Science and Applications Division (MSAD) sponsors science experiments on a variety of microgravity carriers, including Orbiter missions and Russia's Mir space station. The MSAD sponsors the Space Acceleration Measurement System (SAMS) at the NASA Lewis Research Center (LERC) to support these science experiments by providing acceleration measurements to characterize the microgravity environment to which the experiments were exposed. The LeRC Principal Investigator Microgravity Services (PIMS) project supports principal investigations of microgravity science experiments as they evaluate the effects of varying acceleration levels on their experiments. In 1994, a SAMS unit was installed on the Mir space station. In a manner similar to Orbiter mission support, the SAMS unit supports science experiments from the U.S. and Russia by measuring the microgravity environment during experiment operations. Previous reports have summarized the SAMS data acquired during the period from September 1994 to November 1995. During the time period from November 1995 to March 1996, the primary SAMS-supported experiment was a Protein Crystal Growth (PCG) experiment. SAMS data were obtained during the PCG operations on Mir in accordance with the requirements specified by the PCG Principal Investigator. Also included in this data are mission events of interest, such as the undocking of STS-74 from Mir (November 1995) and the docking of Atlantis (STS-76) to Mir in March 1996. This report presents an overview of the SAMS data recorded in the interval from November 1995 to March 1996.

  5. The allocation of cargo to channel missions

    SciTech Connect

    Liu, Cheng; Harrison, G.

    1992-01-01

    Each month the armed services provide a forecast of tons of cargo by channel to MAC. The purpose of the Channels Allocation Algorithm is to allocate cargo requirements to specific Channel Missions. The objective of the allocation is algorithm is to minimize frequency and cargo requirements shortfall. The constraints on the allocation model include flying hours, channel frequencies, mission structure, mission operation days, and aircraft capacity. Cargo requirements shortfall is defined as the tonnage of cargo not moved from the airfields in the United States that are channel staging points to overseas locations. Channel frequencies are defined by the number of times a destination is served by an origin in one month. The mission structures are defined as sets of missions usually in the form of circuit. Mission operating days are determined by the operating day rules for the month, or they can be input by the user for an individual month. One of the assumptions in this model is that there is only one transshipment allowed between any origin and a destination if there is no mission that actually connects the stations. The transshipment stations are also restricted in that only certain stations can serve as transshipment stations. The Channels Allocation Algorithm consists of two linear programs that incorporate three objectives. The objectives are: (1) to minimize that number of frequency channels not met. (2) to minimize cargo shortfall, and (3) to minimize operating cost. The first linear program minimizes frequency channels not met, subject to the mission structure, number of times the mission operates, and total flying hours available. The second linear program minimizes the fleet operating cost cargo handling cost, and cargo shortfall, subject to frequency channels met by the first linear program, aircraft capacity, and total flying hours available. This document is comprised of viewgraphs.

  6. The allocation of cargo to channel missions

    SciTech Connect

    Liu, Cheng; Harrison, G.

    1992-06-01

    Each month the armed services provide a forecast of tons of cargo by channel to MAC. The purpose of the Channels Allocation Algorithm is to allocate cargo requirements to specific Channel Missions. The objective of the allocation is algorithm is to minimize frequency and cargo requirements shortfall. The constraints on the allocation model include flying hours, channel frequencies, mission structure, mission operation days, and aircraft capacity. Cargo requirements shortfall is defined as the tonnage of cargo not moved from the airfields in the United States that are channel staging points to overseas locations. Channel frequencies are defined by the number of times a destination is served by an origin in one month. The mission structures are defined as sets of missions usually in the form of circuit. Mission operating days are determined by the operating day rules for the month, or they can be input by the user for an individual month. One of the assumptions in this model is that there is only one transshipment allowed between any origin and a destination if there is no mission that actually connects the stations. The transshipment stations are also restricted in that only certain stations can serve as transshipment stations. The Channels Allocation Algorithm consists of two linear programs that incorporate three objectives. The objectives are: (1) to minimize that number of frequency channels not met. (2) to minimize cargo shortfall, and (3) to minimize operating cost. The first linear program minimizes frequency channels not met, subject to the mission structure, number of times the mission operates, and total flying hours available. The second linear program minimizes the fleet operating cost cargo handling cost, and cargo shortfall, subject to frequency channels met by the first linear program, aircraft capacity, and total flying hours available. This document is comprised of viewgraphs.

  7. Adaptive Control Allocation in the Presence of Actuator Failures

    NASA Technical Reports Server (NTRS)

    Liu, Yu; Crespo, Luis G.

    2010-01-01

    In this paper, a novel adaptive control allocation framework is proposed. In the adaptive control allocation structure, cooperative actuators are grouped and treated as an equivalent control effector. A state feedback adaptive control signal is designed for the equivalent effector and allocated to the member actuators adaptively. Two adaptive control allocation algorithms are proposed, which guarantee closed-loop stability and asymptotic state tracking in the presence of uncertain loss of effectiveness and constant-magnitude actuator failures. The proposed algorithms can be shown to reduce the controller complexity with proper grouping of the actuators. The proposed adaptive control allocation schemes are applied to two linearized aircraft models, and the simulation results demonstrate the performance of the proposed algorithms.

  8. Sam68 Mediates the Activation of Insulin and Leptin Signalling in Breast Cancer Cells

    PubMed Central

    Pérez-Pérez, Antonio; Sánchez-Jiménez, Flora; Vilariño-García, Teresa; de la Cruz, Luis; Virizuela, Juan A.; Sánchez-Margalet, Víctor

    2016-01-01

    Obesity is a well-known risk factor for breast cancer development in postmenopausal women. High insulin and leptin levels seem to have a role modulating the growth of these tumours. Sam68 is an RNA-binding protein with signalling functions that has been found to be overexpressed in breast cancer. Moreover, Sam68 may be recruited to insulin and leptin signalling pathways, mediating its effects on survival, growth and proliferation in different cellular types. We aimed to study the expression of Sam68 and its phosphorylation level upon insulin and leptin stimulation, and the role of Sam68 in the proliferative effect and signalling pathways that are activated by insulin or leptin in human breast adenocarcinoma cells. In the human breast adenocarcinoma cell lines MCF7, MDA-MB-231 and BT-474, Sam68 protein quantity and gene expression were increased upon leptin or insulin stimulation, as it was checked by qPCR and immunoblot. Moreover, both insulin and leptin stimulation promoted an increase in Sam68 tyrosine phosphorylation and negatively regulated its RNA binding capacity. siRNA was used to downregulate Sam68 expression, which resulted in lower proliferative effects of both insulin and leptin, as well as a lower activation of MAPK and PI3K pathways promoted by both hormones. These effects may be partly explained by the decrease in IRS-1 expression by down-regulation of Sam68. These results suggest the participation of Sam68 in both leptin and insulin receptor signaling in human breast cancer cells, mediating the trophic effects of these hormones in proliferation and cellular growth. PMID:27415018

  9. Student-Based Allocation to Enable School Choice. Schools in Crisis: Making Ends Meet

    ERIC Educational Resources Information Center

    Roza, Marguerite; Simburg, Suzanne

    2013-01-01

    One way districts can enable funding portability is with the use of student-based allocation formulas that allocate funds to districts and schools based on enrollment of students and student types. The student-based allocation model enables "pocketbook power," creating incentives for schools to attract students, keep full enrollment, and…

  10. The Dynamic of Annual Carbon Allocation to Wood in European Forests Is Consistent with a Combined Source-Sink Limitation of Growth: Implications on Growth Simulations in a Terrestrial Biosphere Model

    NASA Astrophysics Data System (ADS)

    Guillemot, J.; Martin-StPaul, N. K.; Dufrêne, E.; François, C.; Soudani, K.; Ourcival, J. M.; Leadley, P.; Delpierre, N.

    2014-12-01

    The extent to which forest growth is limited by carbon (C) supply (source control) or by cambial activity (sink control) will strongly determines the responses of trees to global changes. However, the physiological processes responsible for the limitation of forest growth are still under debate. The aim of this study was i) to evaluate the key drivers of the annual carbon allocation to wood along large soil and climate regional gradients in four tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex and Picea abies) ii) to implement the identified key drivers in a new C allocation scheme within the CASTANEA terrestrial biosphere model (TBM). Combining field measurements and process-based simulations at 49 sites (931 site-years), our analyses revealed that the inter-site variability in C allocation to wood was predominantly driven by an age-related decline. The direct control of temperature or water stress on sink activity (i.e. independently from their effects on C supply) exerted a strong influence on the annual woody growth in all the species considered, including deciduous temperate species. The lagged effect of the past environment conditions was a significant driver of the annual C allocation to wood. Carbon supply appeared to strongly limit growth only in deciduous temperate species. Our study supports the premise that European forest growth is under a complex panel of source- and sink- limitations, contradicting the simple source control implemented in most TBMs. The implementation of these combined forest growth limitations in the CASTANEA model significantly improved its performance when evaluated against independent stand growth data at the regional scale (mainland France, >103 plots). We finally discuss how the sink imitation affects the CASTANEA simulated projections of forest productivity along the 21th century, especially with respect to the expected fertilizing effect of increasing atmospheric

  11. An intercomparison of nitrogen-containing species in Nimbus 7 LIMS and SAMS data

    NASA Technical Reports Server (NTRS)

    Jackman, Charles H.; Guthrie, Paul D.; Kaye, Jack A.

    1987-01-01

    Odd-nitrogen chemistry and transport are analyzed using a two-dimensional model and Nimbus 7 data. The Nimbus 7 data include: measurements of O3, NO2, HNO3, H2O, and temperature by the LIMS instrument; N2O, CH4, and temperature measurements by the SAMS instrument; and O3 data from the SBUV instrument. The characteristics of the two-dimensional model used in the study, a modified Guthrie et al. (1984) model, are described. NO2 and HNO3 are calculated using the two-dimensional model, and the computed data are compared with the LIMS NO2 and HNO3 measurements. The model uncertainties are computed based on the photochemical equilibrium assumption, and the role of stratospheric dynamics in determining NO2 and HNO3 is discussed. It is observed that there is good correlation between the LIMS and model data in the upper stratosphere; however, the data do not correspond in the lower stratosphere. The effect of nitrogen sources, such as lightning, on the stratospheric odd nitrogen distribution is examined.

  12. Denitrification of the polar winter stratosphere - Implications of SAM II cloud formation temperatures

    NASA Technical Reports Server (NTRS)

    Hamill, Patrick; Toon, O. B.

    1990-01-01

    The SAM II extinction profiles and the associated temperature profiles are used to determine the amount of denitrification of the winter polar stratospheres. Clear evidence of the denitrification process in the Antarctic data is seen. There are indications in the Arctic data that denitrification mechanisms may be at work there also. At the latitudes observed by the SAM II satellite system, denitrification begins before the formation of extensive ice clouds and may be due to sedimentation of nitric acid particles. However, the possibility of dinitrification by type II PSCs at latitudes not observed by SAM II cannot be excluded.

  13. A comparative study of aerosol extinction measurements made by the SAM II and SAGE satellite experiments

    NASA Technical Reports Server (NTRS)

    Yue, G. K.; Mccormick, M. P.; Chu, W. P.

    1984-01-01

    SAM II and SAGE are two satellite experiments designed to measure stratospheric aerosol extinction using the technique of solar occultation or limb extinction. Although each sensor is mounted aboard a different satellite, there are occasions when their measurement locations are nearly coincident, thereby providing opportunities for a measurement comparison. In this paper, the aerosol extinction profiles and daily contour plots for some of these events in 1979 are reported. The comparisons shown in this paper demonstrate that SAM II and SAGE are producing similar aerosol extinction profiles within their measurement errors and that since SAM II has been previously validated, these results show the validity of the SAGE aerosol measurements.

  14. 1985 NAPAP EMISSIONS INVENTORY: DEVELOPMENT OF SPATIAL ALLOCATION FACTORS

    EPA Science Inventory

    The report documents the development and application of spatial allocation factors for the 1985 National Acid Precipitation Assessment program(NAPAP) Emissions Inventory (Version 2). The 1985 annual inventory and related modelers' inventory represent the most comprehensive and hi...

  15. 42 CFR 121.8 - Allocation of organs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... PROCUREMENT AND TRANSPLANTATION NETWORK § 121.8 Allocation of organs. (a) Policy development. The Board of..., including the results of model-based computer simulations, as the Secretary may require to assess the...

  16. 42 CFR 121.8 - Allocation of organs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... PROCUREMENT AND TRANSPLANTATION NETWORK § 121.8 Allocation of organs. (a) Policy development. The Board of..., including the results of model-based computer simulations, as the Secretary may require to assess the...

  17. 42 CFR 121.8 - Allocation of organs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... PROCUREMENT AND TRANSPLANTATION NETWORK § 121.8 Allocation of organs. (a) Policy development. The Board of..., including the results of model-based computer simulations, as the Secretary may require to assess the...

  18. 42 CFR 121.8 - Allocation of organs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... PROCUREMENT AND TRANSPLANTATION NETWORK § 121.8 Allocation of organs. (a) Policy development. The Board of..., including the results of model-based computer simulations, as the Secretary may require to assess the...

  19. 42 CFR 121.8 - Allocation of organs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... PROCUREMENT AND TRANSPLANTATION NETWORK § 121.8 Allocation of organs. (a) Policy development. The Board of..., including the results of model-based computer simulations, as the Secretary may require to assess the...

  20. Large scale study on the variation of RF energy absorption in the head & brain regions of adults and children and evaluation of the SAM phantom conservativeness

    NASA Astrophysics Data System (ADS)

    Keshvari, J.; Kivento, M.; Christ, A.; Bit-Babik, G.

    2016-04-01

    This paper presents the results of two computational large scale studies using highly realistic exposure scenarios, MRI based human head and hand models, and two mobile phone models. The objectives are (i) to study the relevance of age when people are exposed to RF by comparing adult and child heads and (ii) to analyze and discuss the conservativeness of the SAM phantom for all age groups. Representative use conditions were simulated using detailed CAD models of two mobile phones operating between 900 MHz and 1950 MHz including configurations with the hand holding the phone, which were not considered in most previous studies. The peak spatial-average specific absorption rate (psSAR) in the head and the pinna tissues is assessed using anatomically accurate head and hand models. The first of the two mentioned studies involved nine head-, four hand- and two phone-models, the second study included six head-, four hand- and three simplified phone-models (over 400 configurations in total). In addition, both studies also evaluated the exposure using the SAM phantom. Results show no systematic differences between psSAR induced in the adult and child heads. The exposure level and its variation for different age groups may be different for particular phones, but no correlation between psSAR and model age was found. The psSAR from all exposure conditions was compared to the corresponding configurations using SAM, which was found to be conservative in the large majority of cases.

  1. Water exchanges versus water works: Insights from a computable general equilibrium model for the Balearic Islands

    NASA Astrophysics Data System (ADS)

    Gómez, Carlos M.; Tirado, Dolores; Rey-Maquieira, Javier

    2004-10-01

    We present a computable general equilibrium model (CGE) for the Balearic Islands, specifically performed to analyze the welfare gains associated with an improvement in the allocation of water rights through voluntary water exchanges (mainly between the agriculture and urban sectors). For the implementation of the empirical model we built the social accounting matrix (SAM) from the last available input-output table of the islands (for the year 1997). Water exchanges provide an important alternative to make the allocation of water flexible enough to cope with the cyclical droughts that characterize the natural water regime on the islands. The main conclusion is that the increased efficiency provided by "water markets" makes this option more advantageous than the popular alternative of building new desalinization plants. Contrary to common opinion, a "water market" can also have positive and significant impacts on the agricultural income.

  2. Water exchanges versus water works: Insights from a computable general equilibrium model for the Balearic Islands

    NASA Astrophysics Data System (ADS)

    Gómez, Carlos M.; Tirado, Dolores; Rey-Maquieira, Javier

    2004-10-01

    We present a computable general equilibrium model (CGE) for the Balearic Islands, specifically performed to analyze the welfare gains associated with an improvement in the allocation of water rights through voluntary water exchanges (mainly between the agriculture and urban sectors). For the implementation of the empirical model we built the social accounting matrix (SAM) from the last available input-output table of the islands (for the year 1997). Water exchanges provide an important alternative to make the allocation of water flexible enough to cope with the cyclical droughts that characterize the natural water regime on the islands. The main conclusion is that the increased efficiency provided by ``water markets'' makes this option more advantageous than the popular alternative of building new desalinization plants. Contrary to common opinion, a ``water market'' can also have positive and significant impacts on the agricultural income.

  3. Ethical considerations surrounding survival benefit-based liver allocation.

    PubMed

    Keller, Eric J; Kwo, Paul Y; Helft, Paul R

    2014-02-01

    The disparity between the demand for and supply of donor livers has continued to grow over the last 2 decades, and this has placed greater weight on the need for efficient and effective liver allocation. Although the use of extended criteria donors has shown great potential, it remains unregulated. A survival benefit-based model was recently proposed to answer calls to increase efficiency and reduce futile transplants. However, it was previously determined that the current allocation system was not in need of modification and that instead geographic disparities should be addressed. In contrast, we believe that there is a significant need to replace the current allocation system and complement efforts to improve donor liver distribution. We illustrate this need first by identifying major ethical concerns shaping liver allocation and then by using these concerns to identify strengths and shortcomings of the Model for End-Stage Liver Disease/Pediatric End-Stage Liver Disease system and a survival benefit-based model. The latter model is a promising means of improving liver allocation: it incorporates a greater number of ethical principles, uses a sophisticated statistical model to increase efficiency and reduce waste, minimizes bias, and parallels developments in the allocation of other organs. However, it remains limited in its posttransplant predictive accuracy and may raise potential issues regarding informed consent. In addition, the proposed model fails to include quality-of-life concerns and prioritize younger patients. We feel that it is time to take the next steps toward better liver allocation not only through reductions in geographic disparities but also through the adoption of a model better equipped to balance the many ethical concerns shaping organ allocation. Thus, we support the development of a similar model with suggested amendments. PMID:24166860

  4. Collaborative Resource Allocation

    NASA Technical Reports Server (NTRS)

    Wang, Yeou-Fang; Wax, Allan; Lam, Raymond; Baldwin, John; Borden, Chester

    2007-01-01

    Collaborative Resource Allocation Networking Environment (CRANE) Version 0.5 is a prototype created to prove the newest concept of using a distributed environment to schedule Deep Space Network (DSN) antenna times in a collaborative fashion. This program is for all space-flight and terrestrial science project users and DSN schedulers to perform scheduling activities and conflict resolution, both synchronously and asynchronously. Project schedulers can, for the first time, participate directly in scheduling their tracking times into the official DSN schedule, and negotiate directly with other projects in an integrated scheduling system. A master schedule covers long-range, mid-range, near-real-time, and real-time scheduling time frames all in one, rather than the current method of separate functions that are supported by different processes and tools. CRANE also provides private workspaces (both dynamic and static), data sharing, scenario management, user control, rapid messaging (based on Java Message Service), data/time synchronization, workflow management, notification (including emails), conflict checking, and a linkage to a schedule generation engine. The data structure with corresponding database design combines object trees with multiple associated mortal instances and relational database to provide unprecedented traceability and simplify the existing DSN XML schedule representation. These technologies are used to provide traceability, schedule negotiation, conflict resolution, and load forecasting from real-time operations to long-range loading analysis up to 20 years in the future. CRANE includes a database, a stored procedure layer, an agent-based middle tier, a Web service wrapper, a Windows Integrated Analysis Environment (IAE), a Java application, and a Web page interface.

  5. OARE and SAMS on STS-94/MSL-1

    NASA Technical Reports Server (NTRS)

    Moskowitz, Milton; Hrovat, Kenneth; McPherson, Kevin; Tschen, Peter; DeLombard, Richard; Nati, Maurizio

    1998-01-01

    Four microgravity acceleration measurement instruments were included on MSL-1 to measure the accelerations and vibrations to which science experiments were exposed during their operation on the mission. The data were processed and presented to the principal investigators in a variety of formats to aid their assessment of the microgravity environment during their experiment operations. Two accelerometer systems managed by the NASA Lewis Research Center (LeRC) supported the MSL-1 mission: the Orbital Acceleration Research Experiment (OARE), and the Space Acceleration Measurement System (SAMS). In addition, the Microgravity Measurement Assembly (MMA) and the Quasi- Steady Acceleration Measurement (QSAM) system, both sponsored by the Microgravity Research Division, collected acceleration data as a part of the MSL-1 mission. The NIMA was funded and designed by the European Space Agency in the Netherlands (ESA/ESTEC), and the QSAM system was funded and designed by the German Space Agency (DLR). The Principal Investigator Microgravity Services (PIMS) project at the NASA Lewis Research Center (LeRC) supports Principal Investigators (PIs) of the Microgravity science community as they evaluate the effects of acceleration on their experiments. PIMS primary responsibility is to support NASA-sponsored investigators in the area of acceleration data analysis and interpretation. A mission summary report was prepared and published by PIMS in order to furnish interested experiment investigators with a guide for evaluating the acceleration environment during the MSL-1 mission.

  6. Recursive SAM-based band selection for hyperspectral anomaly detection

    NASA Astrophysics Data System (ADS)

    He, Yuanlei; Liu, Daizhi; Yi, Shihua

    2010-10-01

    Band selection has been widely used in hyperspectral image processing for dimension reduction. In this paper, a recursive SAM-based band selection (RSAM-BBS) method is proposed. Once two initial bands are given, RSAM-BBS is performed in a sequential manner, and at each step the band that can best describe the spectral separation of two hyperspectral signatures is added to the bands already selected until the spectral angle reaches its maximum. In order to demonstrate the utility of the proposed band selection method, an anomaly detection algorithm is developed, which first extracts the anomalous target spectrum from the original image using automatic target detection and classification algorithm (ATDCA), followed by maximum spectral screening (MSS) to estimate the background average spectrum, then implements RSAM-BBS to select bands that participate in the subsequent adaptive cosine estimator (ACE) target detection. As shown in the experimental result on the AVIRIS dataset, less than five bands selected by the RSAM-BBS can achieve comparable detection performance using the full bands.

  7. ExoDat Information System at CeSAM

    NASA Astrophysics Data System (ADS)

    Agneray, F.; Moreau, C.; Chabaud, P.; Damiani, C.; Deleuil, M.

    2014-05-01

    CoRoT (Convection Rotation and planetary transits) is a space based mission led by French space agency (CNES) in association with French and international laboratories. One of CoRoT's goal is to detect exoplanets by the transit method. The Exoplanet Database (Exodat) is a VO compliant information system for the CoRoT exoplanet program. The main functions of ExoDat are to provide a source catalog for the observation fields and targets selection; to characterize the CoRoT targets (spectral type, variability , contamination...);and to support follow up programs. ExoDat is built using the AstroNomical Information System (ANIS) developed by the CeSAM (Centre de donneeS Astrophysique de Marseille). It offers download of observation catalogs and additional services like: search, extract and display data by using a combination of criteria, object list, and cone-search interfaces. Web services have been developed to provide easy access for user's softwares and pipelines.

  8. Conformational Heterogeneity of the SAM-I Riboswitch Transcriptional ON State: A Chaperone-like Role for S-adenosylmethionine

    PubMed Central

    Huang, Wei; Kim, Joohyun; Jha, Shantenu; Aboul-ela, Fareed

    2016-01-01

    Riboswitches are promising targets for the design of novel antibiotics and engineering of portable genetic regulatory elements. There is evidence that variability in riboswitch properties allows tuning of expression for genes involved in different stages of biosynthetic pathways by mechanisms that are not currently understood. Here we explore the mechanism for tuning of SAM-I riboswitch folding. Most SAM-I riboswitches function at the transcriptional level by sensing the cognate ligand— S-adenosyl methionine (SAM). SAM-I riboswitches orchestrate the biosynthetic pathways of cysteine, methionine and SAM, etc. We use base pair probability predictions to examine the secondary structure folding landscape of several SAM-I riboswitch sequences. We predict different folding behaviors for different SAM-I riboswitch sequences. We identify several “decoy” base pairing interactions involving 5’ riboswitch residues that can compete with the formation of a P1 helix, a component of the ligand-bound “transcription OFF” state, in the absence of SAM. We hypothesize that blockage of these interactions through SAM contacts contributes to stabilization of the OFF state in the presence of ligand. We also probe folding patterns for a SAM-I riboswitch RNA using constructs with different 3’ truncation points experimentally. Folding was monitored through fluorescence, susceptibility to base-catalyzed cleavage, nuclear magnetic resonance and indirectly through SAM binding. We identify key decision windows at which SAM can affect the folding pathway toward the OFF state. The presence of decoy conformations and differential sensitivities to SAM at different transcript lengths are crucial for SAM-I riboswitches to modulate gene expression in the context of global cellular metabolism. PMID:22425639

  9. Self-organizing map (SOM) of space acceleration measurement system (SAMS) data.

    PubMed

    Sinha, A; Smith, A D

    1999-01-01

    In this paper, space acceleration measurement system (SAMS) data have been classified using self-organizing map (SOM) networks without any supervision; i.e., no a priori knowledge is assumed regarding input patterns belonging to a certain class. Input patterns are created on the basis of power spectral densities of SAMS data. Results for SAMS data from STS-50 and STS-57 missions are presented. Following issues are discussed in details: impact of number of neurons, global ordering of SOM weight vectors, effectiveness of a SOM in data classification, and effects of shifting time windows in the generation of input patterns. The concept of 'cascade of SOM networks' is also developed and tested. It has been found that a SOM network can successfully classify SAMS data obtained during STS-50 and STS-57 missions. PMID:11543426

  10. Introduction to the Thematic Minireview Series on Radical S-Adenosylmethionine (SAM) Enzymes*

    PubMed Central

    Banerjee, Ruma

    2015-01-01

    In the early days, radical enzyme reactions that use S-adenosylmethionine (SAM) coordinated to an Fe-S cluster, which Perry Frey described as a “poor man's coenzyme B12,” were believed to be relatively rare chemical curiosities. Today, bioinformatics analyses have revealed the wide prevalence and sheer numbers of radical SAM enzymes, conferring superfamily status. In this thematic minireview series, the JBC presents six articles on radical SAM enzymes that accomplish wide-ranging chemical transformations. We learn that despite the diversity of the reactions catalyzed, family members share some common structural and mechanistic themes. Still in its infancy, continued explorations promise to be fertile grounds for discoveries that will undoubtedly further broaden our understanding of the catalytic repertoire and deepen our understanding of the chemical strategies used by radical SAM enzymes. PMID:25477525

  11. Self-organizing map (SOM) of space acceleration measurement system (SAMS) data

    NASA Technical Reports Server (NTRS)

    Sinha, A.; Smith, A. D.

    1999-01-01

    In this paper, space acceleration measurement system (SAMS) data have been classified using self-organizing map (SOM) networks without any supervision; i.e., no a priori knowledge is assumed regarding input patterns belonging to a certain class. Input patterns are created on the basis of power spectral densities of SAMS data. Results for SAMS data from STS-50 and STS-57 missions are presented. Following issues are discussed in details: impact of number of neurons, global ordering of SOM weight vectors, effectiveness of a SOM in data classification, and effects of shifting time windows in the generation of input patterns. The concept of 'cascade of SOM networks' is also developed and tested. It has been found that a SOM network can successfully classify SAMS data obtained during STS-50 and STS-57 missions.

  12. Development of and flight results from the Space Acceleration Measurement System (SAMS)

    NASA Technical Reports Server (NTRS)

    Delombard, Richard; Finley, Brian D.; Baugher, Charles R.

    1992-01-01

    Described here is the development of and the flight results from the Space Acceleration Measurement System (SAMS) flight units used in the Orbiter middeck, Spacelab module, and the Orbitercargo bay. The SAMS units are general purpose microgravity accelerometers designed to support a variety of science experiments with microgravity acceleration measurements. A total of six flight units have been fabricated; four for use in the Orbiter middeck and Spacelab module, and two for use in the Orbiter cargo bay. The design of the units is briefly described. The initial two flights of SAMS units on STS-40 (June 1991) and STS-43 (August 1991) resulted in 371 megabytes and 2.6 gigabytes of data respectively. Analytical techniques developed to examine this quantity of acceleration data are described and sample plots of analyzed data are illustrated. Future missions for the SAMS units are listed.

  13. Tandem SAM Domain Structure of Human Caskin1: A Presynaptic, Self-Assembling Scaffold for CASK

    SciTech Connect

    Stafford, Ryan L.; Hinde, Elizabeth; Knight, Mary Jane; Pennella, Mario A.; Ear, Jason; Digman, Michelle A.; Gratton, Enrico; Bowie, James U.

    2012-02-07

    The synaptic scaffolding proteins CASK and Caskin1 are part of the fibrous mesh of proteins that organize the active zones of neural synapses. CASK binds to a region of Caskin1 called the CASK interaction domain (CID). Adjacent to the CID, Caskin1 contains two tandem sterile a motif (SAM) domains. Many SAM domains form polymers so they are good candidates for forming the fibrous structures seen in the active zone. We show here that the SAM domains of Caskin1 form a new type of SAM helical polymer. The Caskin1 polymer interface exhibits a remarkable segregation of charged residues, resulting in a high sensitivity to ionic strength in vitro. The Caskin1 polymers can be decorated with CASK proteins, illustrating how these proteins may work together to organize the cytomatrix in active zones.

  14. Tandem SAM Domain Structure of Human Caskin1: A Presynaptic, Self-Assembling Scaffold for CASK

    PubMed Central

    Stafford, Ryan L.; Hinde, Elizabeth; Knight, Mary Jane; Pennella, Mario A.; Ear, Jason; Digman, Michelle A.; Gratton, Enrico; Bowie, James U.

    2011-01-01

    Summary The synaptic scaffolding proteins CASK and Caskin1 are part of the fibrous mesh of proteins that organize the active zones of neural synapses. CASK binds to a region of Caskin1 called the CASK interaction domain (CID). Adjacent to the CID, Caskin1 contains two tandem sterile alpha motif (SAM) domains. Many SAM domains form polymers so they are good candidates for forming the fibrous structures seen in the active zone. We show here that the SAM domains of Caskin1 form a new type of SAM helical polymer. The Caskin1 polymer interface exhibits a remarkable segregation of charge residues, resulting in a high sensitivity to ionic strength in vitro. The Caskin1 polymers can be decorated with CASK proteins, illustrating how these proteins may work together to organize the cytomatrix in active zones. PMID:22153505

  15. SAmBA: an interactive software for optimizing the design of biological macromolecules crystallization experiments.

    PubMed

    Audic, S; Lopez, F; Claverie, J M; Poirot, O; Abergel, C

    1997-10-01

    SAmBA is a new software for the design of minimal experimental protocols using the notion of orthogonal arrays of strength 2. The main application of SAmBA is the search of protein crystallization conditions. Given a user input defining the relevant effectors/variables (e.g., pH, temperature, salts) and states (e.g., pH: 5, 6, 7 and 8), this software proposes an optimal set of experiments in which all tested variables and the pairwise interactions between them are symmetrically sampled. No a priori restrictions on the number and range of experimental variables is imposed. SAmBA consists of two complementary programs, SAm and BA, using a simulated annealing approach and a backtracking algorithm, respectively. The software is freely available as C code or as an interactive JAVA applet at http:/(/)igs-server.cnrs-mrs.fr. PMID:9329089

  16. Radical SAM enzymes involved in the biosynthesis of purine-based natural products

    PubMed Central

    Bandarian, Vahe

    2013-01-01

    The radical S-adenosyl-L-methionine (SAM) superfamily is a widely distributed group of iron-sulfur containing proteins that exploit the reactivity of the high energy intermediate, 5’-deoxyadenosyl radical, which is produced by reductive cleavage of SAM, to carry-out complex radical-mediated transformations. The reactions catalyzed by radical SAM enzymes range from simple group migrations to complex reactions in protein and RNA modification. This review will highlight three radical SAM enzymes that catalyze reactions involving modified guanosines in the biosynthesis pathways of the hypermodified tRNA base wybutosine; secondary metabolites of 7-deazapurine structure, including the hypermodified tRNA base queuosine; and the redox cofactor F420. PMID:22902275

  17. Radical SAM enzymes in the biosynthesis of sugar-containing natural products.

    PubMed

    Ruszczycky, Mark W; Ogasawara, Yasushi; Liu, Hung-Wen

    2012-11-01

    Carbohydrates play a key role in the biological activity of numerous natural products. In many instances their biosynthesis requires radical mediated rearrangements, some of which are catalyzed by radical SAM enzymes. BtrN is one such enzyme responsible for the dehydrogenation of a secondary alcohol in the biosynthesis of 2-deoxystreptamine. DesII is another example that catalyzes a deamination reaction necessary for the net C4 deoxygenation of a glucose derivative en route to desosamine formation. BtrN and DesII represent the two most extensively characterized radical SAM enzymes involved in carbohydrate biosynthesis. In this review, we summarize the biosynthetic roles of these two enzymes, their mechanisms of catalysis, the questions that have arisen during these investigations and the insight they can offer for furthering our understanding of radical SAM enzymology. This article is part of a Special Issue entitled: Radical SAM enzymes and Radical Enzymology. PMID:22172915

  18. Radical SAM enzymes in the biosynthesis of sugar-containing natural products☆

    PubMed Central

    Ruszczycky, Mark W.; Ogasawara, Yasushi; Liu, Hung-wen

    2012-01-01

    Carbohydrates play a key role in the biological activity of numerous natural products. In many instances their biosynthesis requires radical mediated rearrangements, some of which are catalyzed by radical SAM enzymes. BtrN is one such enzyme responsible for the dehydrogenation of a secondary alcohol in the biosynthesis of 2-deoxystreptamine. DesII is another example that catalyzes a deamination reaction necessary for the net C4 deoxygenation of a glucose derivative en route to desosamine formation. BtrN and DesII represent the two most extensively characterized radical SAM enzymes involved in carbohydrate biosynthesis. In this review, we summarize the biosynthetic roles of these two enzymes, their mechanisms of catalysis, the questions that have arisen during these investigations and the insight they can offer for furthering our understanding of radical SAM enzymology. This article is part of a Special Issue entitled: Radical SAM enzymes and Radical Enzymology. PMID:22172915

  19. Intercomparison of nitrogen-containing species in Nimbus 7 LIMS and SAMS Data

    SciTech Connect

    Jackman, C.H.; Guthrie, P.D.; Kaye, J.A.

    1987-01-20

    Nitrogen dioxide (NO/sub 2/) and nitric acid (HNO/sub 3/) distributions were derived with a two-dimensional time-dependent model using N/sub 2/O, CH/sub 4/, and temperature measurements from the stratospheric and mesospheric sounder (SAMS) along with H/sub 2/O measurements from the limb infrared monitor of the stratosphere (LIMS) and O/sub 3/ measurements from the solar backscatter ultraviolet (SBUV) instrument. All three instruments (SAMS, LIMS, and SBUV) were aboard the Nimbus 7 satellite. The computed NO/sub 2/ and HNO/sub 3/ were compared with LIMS NO/sub 2/ and HNO/sub 3/ measurements. Calculated NO/sub 2/ is lower than the LIMS NO/sub 2/ in much of the lower stratosphere by about a factor of 4 or more. Differences in the upper stratosphere between derived NO/sub 2/ and LIMS NO/sub 2/ are within the photochemical uncertainties of the computation. Derived NO/sub 2/ is much larger than LIMS NO/sub 2/ at high latitudes in the upper stratosphere in December, indicating that dynamics and/or photochemistry in the atmosphere are different from those used in the model. Derived HNO/sub 3/ is in fairly good agreement with LIMS HNO/sub 3/ in the upper stratosphere. Derived and LIMS HNO/sub 3/ gradually become more different through the middle stratosphere and reach a fairly substantial disagreement in the lower stratosphere. The high-latitude maxima observed in LIMS HNO/sub 3/ are present at lower altitudes and at higher concentrations than those derived in the model computations. More significantly, the derived HNO/sub 3/ at polar latitudes is highest in the summer while LIMS HNO/sub 3/ is highest in the winter. Disagreements in the lower stratosphere between the computed and LIMS NO/sub 2/ and HNO/sub 3/ can only be reduced if two changes are made in the model computations: (1) additional lower stratospheric sources of odd nitrogen (other than N/sub 2/O+O(/sup 1/D)) are included and (2) a modified chemistry to allow the formation of HNO/sub 3/ at the expense of N/sub 2

  20. Bringing a Chemical Laboratory Named Sam to Mars on the 2011 Curiosity Rover

    NASA Astrophysics Data System (ADS)

    Mahaffy, P. R.; Bleacher, L.; Jones, A.; Atreya, S. K.; Manning, H. L.; Cabane, M.; Webster, C. R.; Sam Team

    2010-12-01

    Introduction: An important goal of upcoming missions to Mars is to understand if life could have developed there. The task of the Sample Analysis at Mars (SAM) suite of instruments [1] and the other Curiosity investigations [2] is to move us steadily toward that goal with an assessment of the habitability of our neighboring planet through a series of chemical and geological measurements. SAM is designed to search for organic compounds and inorganic volatiles and measure isotope ratios. Other instruments on Curiosity will provide elemental analysis and identify minerals. SAM will analyze both atmospheric samples and gases evolved from powdered rocks that may have formed billions of years ago with Curiosity providing access to interesting sites scouted by orbiting cameras and spectrometers. SAM Instrument Suite: SAM’s instruments are a Quadrupole Mass Spectrometer (QMS), a 6-column Gas Chromatograph (GC), and a 2-channel Tunable Laser Spectrometer (TLS). SAM can identify organic compounds in Mars rocks to sub-ppb sensitivity and secure precise isotope ratios for C, H, and O in carbon dioxide and water and measure trace levels of methane and its carbon 13 isotope. The SAM gas processing system consists of valves, heaters, pressure sensors, gas scrubbers and getters, traps, and gas tanks used for calibration or combustion experiments [2]. A variety of calibrant compounds interior and exterior to SAM will allow the science and engineering teams to assess SAM’s performance. SAM has been calibrated and tested in a Mars-like environment. Keeping Educators and the Public Informed: The Education and Public Outreach (EPO) goals of the SAM team are to make this complex chemical laboratory and its data widely available to educators, students, and the public. Formal education activities include developing templates for professional development workshops for educators to teach them about SAM and Curiosity, incorporating data into Mars Student Data Teams, and writing articles

  1. Identification of trans-acting factors regulating SamDC expression in Oryza sativa

    SciTech Connect

    Basu, Supratim; Roychoudhury, Aryadeep; Sengupta, Dibyendu N.

    2014-03-07

    Highlights: • Identification of cis elements responsible for SamDC expression by in silico analysis. • qPCR analysis of SamDC expression to abiotic and biotic stress treatments. • Detection of SamDC regulators using identified cis-elements as probe by EMSA. • Southwestern Blot analysis to predict the size of the trans-acting factors. - Abstract: Abiotic stress affects the growth and productivity of crop plants; to cope with the adverse environmental conditions, plants have developed efficient defense machinery comprising of antioxidants like phenolics and flavonoids, and osmolytes like polyamines. SamDC is a key enzyme in the polyamine biosynthesis pathway in plants. In our present communication we have done in silico analysis of the promoter region of SamDC to look for the presence of different cis-regulatory elements contributing to its expression. Based on the presence of different cis-regulatory elements we completed comparative analysis of SamDC gene expression in rice lamina of IR-29 and Nonabokra by qPCR in response to the abiotic stress treatments of salinity, drought, cold and the biotic stress treatments of ABA and light. Additionally, to explore the role of the cis-regulatory elements in regulating the expression of SamDC gene in plants we comparatively analyzed the binding of rice nuclear proteins prepared from IR-29 and Nonabokra undergoing various stress treatments. The intensity of the complex formed was low and inducible in IR-29 in contrast to Nonabokra. Southwestern blot analysis helped in predicting the size of the trans-acting factors binding to these cis-elements. To our knowledge this is the first report on the comprehensive analysis of SamDC gene expression in rice and identification of the trans-acting factors regulating its expression.

  2. Nanoparticle-based solution deposition of gold films supporting bioresistant SAMs.

    PubMed

    Kowalczyk, Bartlomiej; Byrska, Marta; Mahmud, Goher; Huda, Sabil; Kandere-Grzybowska, Kristiana; Grzybowski, Bartosz A

    2009-02-17

    Thin films of gold on glass are prepared by solution deposition of functionalized gold nanoparticles followed by thermal treatment. The processed films adhere strongly to glass without any adhesion layers and can be micropatterned/microetched without delamination from the substrate. The formation of self-assembled monolayers (SAMs) of oligo(ethylene glycol) alkane thiols (EG SAMs) renders the films resistant to cell adhesion and allows for cell patterning. PMID:19170541

  3. The Combustion Experiment on the Sample Analysis at Mars (SAM) Instrument Suite on the Curiosity Rover

    NASA Technical Reports Server (NTRS)

    Stern, J. C.; Malespin, C. A.; Eigenbrode, J. L.; Graham, H. V.; Archer, P. D., Jr.; Brunner, A. E.; Freissinet, C.; Franz, H. B.; Fuentes, J.; Glavin, D. P.; Leshin, L. A.; Mahaffy, P. R.; McAdam, A. C.; Ming, D. W.; Navvaro-Gonzales, R.; Niles, P. B.; Steele, A.

    2014-01-01

    The combustion experiment on the Sample Analysis at Mars (SAM) suite on Curiosity will heat a sample of Mars regolith in the presence of oxygen and measure composition of the evolved gases using quadrupole mass spectrometry (QMS) and tunable laser spectrometry (TLS). QMS will enable detection of combustion products such as CO, CO2, NO, and other oxidized species, while TLS will enable precise measurements of the abundance and carbon isotopic composition (delta(sup 13)C) of the evolved CO2 and hydrogen isotopic composition (deltaD) of H2O. SAM will perform a two-step combustion to isolate combustible materials below approx.550 C and above approx.550 C. The combustion experiment on SAM, if properly designed and executed, has the potential to answer multiple questions regarding the origins of volatiles seen thus far in SAM evolved gas analysis (EGA) on Mars. Constraints imposed by SAM and MSL time and power resources, as well as SAM consumables (oxygen gas), will limit the number of SAM combustion experiments, so it is imperative to design an experiment targeting the most pressing science questions. Low temperature combustion experiments will primarily target the quantification of carbon (and nitrogen) contributed by SAM wet chemistry reagants MTBSTFA (N-Methyl-N-tert-butyldimethylsilyltrifluoroacetamide) and DMF (Dimethylformamide), which have been identified in the background of blank and sample runs and may adsorb to the sample while the cup is in the Sample Manipulation System (SMS). In addition, differences between the sample and "blank" may yield information regarding abundance and delta(sup 13)C of bulk (both organic and inorganic) martian carbon. High temperature combustion experiments primarily aim to detect refractory organic matter, if present in Cumberland fines, as well as address the question of quantification and deltaD value of water evolution associated with hydroxyl hydrogen in clay minerals.

  4. Electronic patient self-assessment and management (SAM): a novel framework for cancer survivorship

    PubMed Central

    2010-01-01

    Background We propose a novel framework for management of cancer survivorship: electronic patient Self-Assessment and Management (SAM). SAM is a framework for transfer of information to and from patients in such a way as to increase both the patient's and the health care provider's understanding of the patient's progress, and to help ensure that patient care follows best practice. Methods Patients who participate in the SAM system are contacted by email at regular intervals and asked to complete validated questionnaires online. Patient responses on these questionnaires are then analyzed in order to provide patients with real-time, online information about their progress and to provide them with tailored and standardized medical advice. Patient-level data from the questionnaires are ported in real time to the patient's health care provider to be uploaded to clinic notes. An initial version of SAM has been developed at Memorial Sloan-Kettering Cancer Center (MSKCC) and the University of California, San Francisco (UCSF) for aiding the clinical management of patients after surgery for prostate cancer. Results Pilot testing at MSKCC and UCSF suggests that implementation of SAM systems are feasible, with no major problems with compliance (> 70% response rate) or security. Conclusion SAM is a conceptually simple framework for passing information to and from patients in such a way as to increase both the patient's and the health care provider's understanding of the patient's progress, and to help ensure that patient care follows best practice. PMID:20565745

  5. Non-canonical active site architecture of the radical SAM thiamin pyrimidine synthase

    DOE PAGESBeta

    Fenwick, Michael K.; Mehta, Angad P.; Zhang, Yang; Abdelwahed, Sameh H.; Begley, Tadhg P.; Ealick, Steven E.

    2015-03-27

    Radical S-adenosylmethionine (SAM) enzymes use a [4Fe-4S] cluster to generate a 5'-deoxyadenosyl radical. Canonical radical SAM enzymes are characterized by a β-barrel-like fold and SAM anchors to the differentiated iron of the cluster, which is located near the amino terminus and within the β-barrel, through its amino and carboxylate groups. Here we show that ThiC, the thiamin pyrimidine synthase in plants and bacteria, contains a tethered cluster-binding domain at its carboxy terminus that moves in and out of the active site during catalysis. In contrast to canonical radical SAM enzymes, we predict that SAM anchors to an additional active sitemore » metal through its amino and carboxylate groups. Superimposition of the catalytic domains of ThiC and glutamate mutase shows that these two enzymes share similar active site architectures, thus providing strong evidence for an evolutionary link between the radical SAM and adenosylcobalamin-dependent enzyme superfamilies.« less

  6. Non-canonical active site architecture of the radical SAM thiamin pyrimidine synthase

    NASA Astrophysics Data System (ADS)

    Fenwick, Michael K.; Mehta, Angad P.; Zhang, Yang; Abdelwahed, Sameh H.; Begley, Tadhg P.; Ealick, Steven E.

    2015-03-01

    Radical S-adenosylmethionine (SAM) enzymes use a [4Fe-4S] cluster to generate a 5‧-deoxyadenosyl radical. Canonical radical SAM enzymes are characterized by a β-barrel-like fold and SAM anchors to the differentiated iron of the cluster, which is located near the amino terminus and within the β-barrel, through its amino and carboxylate groups. Here we show that ThiC, the thiamin pyrimidine synthase in plants and bacteria, contains a tethered cluster-binding domain at its carboxy terminus that moves in and out of the active site during catalysis. In contrast to canonical radical SAM enzymes, we predict that SAM anchors to an additional active site metal through its amino and carboxylate groups. Superimposition of the catalytic domains of ThiC and glutamate mutase shows that these two enzymes share similar active site architectures, thus providing strong evidence for an evolutionary link between the radical SAM and adenosylcobalamin-dependent enzyme superfamilies.

  7. Alternative function for the mitochondrial SAM complex in biogenesis of alpha-helical TOM proteins.

    PubMed

    Stojanovski, Diana; Guiard, Bernard; Kozjak-Pavlovic, Vera; Pfanner, Nikolaus; Meisinger, Chris

    2007-12-01

    The mitochondrial outer membrane contains two preprotein translocases: the general translocase of outer membrane (TOM) and the beta-barrel-specific sorting and assembly machinery (SAM). TOM functions as the central entry gate for nuclear-encoded proteins. The channel-forming Tom40 is a beta-barrel protein, whereas all Tom receptors and small Tom proteins are membrane anchored by a transmembrane alpha-helical segment in their N- or C-terminal portion. Synthesis of Tom precursors takes place in the cytosol, and their import occurs via preexisting TOM complexes. The precursor of Tom40 is then transferred to SAM for membrane insertion and assembly. Unexpectedly, we find that the biogenesis of alpha-helical Tom proteins with a membrane anchor in the C-terminal portion is SAM dependent. Each SAM protein is necessary for efficient membrane integration of the receptor Tom22, whereas assembly of the small Tom proteins depends on Sam37. Thus, the substrate specificity of SAM is not restricted to beta-barrel proteins but also includes the majority of alpha-helical Tom proteins. PMID:18039934

  8. Active Region Soft X-Ray Spectra and Temperature Analyses based on Sounding Rocket Measurements from the Solar Aspect Monitor (SAM), - a Modified SDO/EVE Instrument

    NASA Astrophysics Data System (ADS)

    Didkovsky, Leonid V.; Wieman, Seth; Woods, Thomas N.; Jones, Andrew; Moore, Christopher

    2016-05-01

    Some initial results of soft x-ray spectral (0.5 to 3.0 nm) observations of active regions (AR11877 and AR11875) from a sounding rocket flight NASA 36.290 on 21 October 2013 at about 18:30 UT are reported. These observations were made by a Solar Aspect Monitor (SAM), a rocket version of the EUV Variability Experiment’s (EVE) channel, a pinhole camera modified for EVE rocket suite of instruments to include a free-standing transmission grating (200 nm period), which provided spectrally-resolved images of the solar disk. Intensity ratios for strong emission lines extracted from temporally averaged SAM spectral profiles of the ARs were compared to appropriately convolved modeled CHIANTI spectra. These ratios represent the AR’s temperature structures, which are compared to the structures derived from some other observations and temperature models.

  9. A Distributed Cooperative Power Allocation Method for Campus Buildings

    SciTech Connect

    Hao, He; Sun, Yannan; Carroll, Thomas E.; Somani, Abhishek

    2015-09-01

    We propose a coordination algorithm for cooperative power allocation among a collection of commercial buildings within a campus. We introduced thermal and power models of a typical commercial building Heating, Ventilation, and Air Conditioning (HVAC) system, and utilize model predictive control to characterize their power flexibility. The power allocation problem is formulated as a cooperative game using the Nash Bargaining Solution (NBS) concept, in which buildings collectively maximize the product of their utilities subject to their local flexibility constraints and a total power limit set by the campus coordinator. To solve the optimal allocation problem, a distributed protocol is designed using dual decomposition of the Nash bargaining problem. Numerical simulations are performed to demonstrate the efficacy of our proposed allocation method

  10. Decentralized method for complex task allocation in massive MAS

    NASA Astrophysics Data System (ADS)

    Brahmi, Zaki; Gammoudi, M. M.

    2008-06-01

    Task allocation is still a fundamental problem in Multi-Agents System (MAS). It allows the formation a coalition of agents to cooperate together in order to carry out a complex task. Generally, the process of task allocation requires calculating the value of all the possible allocations, then determining which optimal. In the context of Massive Multi-Agent Systems (MMAS), one agent generates all the possible coalitions and then calculates the value of each, is inefficient. Moreover, the traditional approaches based on the negotiation between agents, are impractical because of the complexity of communications between agents. In this paper we propose a decentralized method, based on grouping agents using the Formal Concepts Analysis (FCA) approach for the task allocation in MMAS. In our model, agents are fully cooperative and each task is composed of several subtasks. The proposed solution is based on two steps: i) computing groups of agents having similar characteristics in the objective to distribute the task allocation process among agents and minimize the communication between agents. ii) Finding the optimal allocation by sharing the task allocation process among groups of agents.

  11. A Role for the GSG Domain in Localizing Sam68 to Novel Nuclear Structures in Cancer Cell Lines

    PubMed Central

    Chen, Taiping; Boisvert, François-Michel; Bazett-Jones, David P.; Richard, Stéphane

    1999-01-01

    The GSG (GRP33, Sam68, GLD-1) domain is a protein module found in an expanding family of RNA-binding proteins. The numerous missense mutations identified genetically in the GSG domain support its physiological role. Although the exact function of the GSG domain is not known, it has been shown to be required for RNA binding and oligomerization. Here it is shown that the Sam68 GSG domain plays a role in protein localization. We show that Sam68 concentrates into novel nuclear structures that are predominantly found in transformed cells. These Sam68 nuclear bodies (SNBs) are distinct from coiled bodies, gems, and promyelocytic nuclear bodies. Electron microscopic studies show that SNBs are distinct structures that are enriched in phosphorus and nitrogen, indicating the presence of nucleic acids. A GFP-Sam68 fusion protein had a similar localization as endogenous Sam68 in HeLa cells, diffusely nuclear with two to five SNBs. Two other GSG proteins, the Sam68-like mammalian proteins SLM-1 and SLM-2, colocalized with endogenous Sam68 in SNBs. Different GSG domain missense mutations were investigated for Sam68 protein localization. Six separate classes of cellular patterns were obtained, including exclusive SNB localization and association with microtubules. These findings demonstrate that the GSG domain is involved in protein localization and define a new compartment for Sam68, SLM-1, and SLM-2 in cancer cell lines. PMID:10473643

  12. 24 CFR 92.50 - Formula allocation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Formula allocation. 92.50 Section 92.50 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development HOME INVESTMENT PARTNERSHIPS PROGRAM Allocation Formula § 92.50 Formula allocation. (a) Jurisdictions eligible for a formula allocation. HUD...

  13. Optimal allocation of file servers in a local network environment

    NASA Technical Reports Server (NTRS)

    Woodside, C. M.; Tripathi, S. K.

    1986-01-01

    Files associated with workstations in a local area network are to be allocated among two or more file servers. Assuming statistically identical workstations and file servers and a performance model which is a closed multiclass separable queueing network, an optimal allocation is found. It is shown that all the files of each workstation should be placed on one file server, with the workstations divided as equally as possible among the file servers.

  14. Optimal allocation under partial ordering of lifetimes of components

    NASA Astrophysics Data System (ADS)

    El-Neweihi, Emad; Sethuraman, Jayaram

    1992-08-01

    Assembly of systems to maximize reliability when certain components of the systems can be bolstered in different ways is an important theme in reliability theory. This is done under assumptions of various stochastic orderings among the lifetimes of the components and the spares used to bolster them. The powerful techniques of Schur and AI functions are used in this paper to pinpoint optimal allocation results in different settings involving active and standby redundancy allocation, minimal repair and shock, threshold models.

  15. SAM-Like Evolved Gas Analyses of Phyllosilicate Minerals and Applications to SAM Analyses of the Sheepbed Mudstone, Gale Crater, Mars

    NASA Technical Reports Server (NTRS)

    McAdam, A. C.; Franz, H. B.; Mahaffy, P. R.; Eigenbrode, J. L.; Stern, J. C.; Brunner, B.; Sutter, B.; Archer, P. D.; Ming , D. W.; Morris, R. V.; Bish, D. L.; Atreya, S. K.

    2014-01-01

    While in Yellowknife Bay, the Mars Science Laboratory Curiosity rover collected two drilled samples, John Klein (hereafter "JK") and Cumberland ("CB"), from the Sheepbed mudstone, as well as a scooped sample from the Rocknest aeolian bedform ("RN"). These samples were sieved by Curiosity's sample processing system and then several subsamples of these materials were delivered to the Sample Analysis at Mars (SAM) instrument suite and the CheMin X-ray diffraction/X-ray fluorescence instrument. CheMin provided the first in situ X-ray diffraction-based evidence of clay minerals on Mars, which are likely trioctahedral smectites (e.g., Fe-saponite) and comprise 20 wt% of the mudstone samples [1]. SAM's evolved gas analysis (EGA) mass spectrometry analyses of JK and CB subsamples, as well as RN subsamples, detected H2O, CO2, O2, H2, SO2, H2S, HCl, NO, OCS, CS2 and other trace gases evolved during pyrolysis. The identity of evolved gases and temperature( s) of evolution can augment mineral detection by CheMin and place constraints on trace volatile-bearing phases present below the CheMin detection limit or those phases difficult to characterize with XRD (e.g., X-ray amorphous phases). Here we will focus on the SAM H2O data, in the context of CheMin analyses, and comparisons to laboratory SAM-like analyses of several phyllosilicate minerals including smectites.

  16. Probing the nature and resistance of the molecule-electrode contact in SAM-based junctions

    NASA Astrophysics Data System (ADS)

    Suchand Sangeeth, C. S.; Wan, Albert; Nijhuis, Christian A.

    2015-07-01

    It is challenging to quantify the contact resistance and to determine the nature of the molecule-electrode contacts in molecular two-terminal junctions. Here we show that potentiodynamic and temperature dependent impedance measurements give insights into the nature of the SAM-electrode interface and other bottlenecks of charge transport (the capacitance of the SAM (CSAM) and the resistance of the SAM (RSAM)), unlike DC methods, independently of each other. We found that the resistance of the top-electrode-SAM contact for junctions with the form of AgTS-SCn//GaOx/EGaIn with n = 10, 12, 14, 16 or 18 is bias and temperature independent and hence Ohmic (non-rectifying) in nature, and is orders of magnitude smaller than RSAM. The CSAM and RSAM are independent of the temperature, indicating that the mechanism of charge transport in these SAM-based junctions is coherent tunneling and the charge carrier trapping at the interfaces is negligible.It is challenging to quantify the contact resistance and to determine the nature of the molecule-electrode contacts in molecular two-terminal junctions. Here we show that potentiodynamic and temperature dependent impedance measurements give insights into the nature of the SAM-electrode interface and other bottlenecks of charge transport (the capacitance of the SAM (CSAM) and the resistance of the SAM (RSAM)), unlike DC methods, independently of each other. We found that the resistance of the top-electrode-SAM contact for junctions with the form of AgTS-SCn//GaOx/EGaIn with n = 10, 12, 14, 16 or 18 is bias and temperature independent and hence Ohmic (non-rectifying) in nature, and is orders of magnitude smaller than RSAM. The CSAM and RSAM are independent of the temperature, indicating that the mechanism of charge transport in these SAM-based junctions is coherent tunneling and the charge carrier trapping at the interfaces is negligible. Electronic supplementary information (ESI) available: Detailed experimental procedure, Nyquist

  17. Collective credit allocation in science

    PubMed Central

    Shen, Hua-Wei; Barabási, Albert-László

    2014-01-01

    Collaboration among researchers is an essential component of the modern scientific enterprise, playing a particularly important role in multidisciplinary research. However, we continue to wrestle with allocating credit to the coauthors of publications with multiple authors, because the relative contribution of each author is difficult to determine. At the same time, the scientific community runs an informal field-dependent credit allocation process that assigns credit in a collective fashion to each work. Here we develop a credit allocation algorithm that captures the coauthors’ contribution to a publication as perceived by the scientific community, reproducing the informal collective credit allocation of science. We validate the method by identifying the authors of Nobel-winning papers that are credited for the discovery, independent of their positions in the author list. The method can also compare the relative impact of researchers working in the same field, even if they did not publish together. The ability to accurately measure the relative credit of researchers could affect many aspects of credit allocation in science, potentially impacting hiring, funding, and promotion decisions. PMID:25114238

  18. Optimal allocation of trend following strategies

    NASA Astrophysics Data System (ADS)

    Grebenkov, Denis S.; Serror, Jeremy

    2015-09-01

    We consider a portfolio allocation problem for trend following (TF) strategies on multiple correlated assets. Under simplifying assumptions of a Gaussian market and linear TF strategies, we derive analytical formulas for the mean and variance of the portfolio return. We construct then the optimal portfolio that maximizes risk-adjusted return by accounting for inter-asset correlations. The dynamic allocation problem for n assets is shown to be equivalent to the classical static allocation problem for n2 virtual assets that include lead-lag corrections in positions of TF strategies. The respective roles of asset auto-correlations and inter-asset correlations are investigated in depth for the two-asset case and a sector model. In contrast to the principle of diversification suggesting to treat uncorrelated assets, we show that inter-asset correlations allow one to estimate apparent trends more reliably and to adjust the TF positions more efficiently. If properly accounted for, inter-asset correlations are not deteriorative but beneficial for portfolio management that can open new profit opportunities for trend followers. These concepts are illustrated using daily returns of three highly correlated futures markets: the E-mini S&P 500, Euro Stoxx 50 index, and the US 10-year T-note futures.

  19. Fluorocarbon Contamination from the Drill on the Mars Science Laboratory: Potential Science Impact on Detecting Martian Organics by Sample Analysis at Mars (SAM)

    NASA Technical Reports Server (NTRS)

    Eigenbrode, J. L.; McAdam, A.; Franz, H.; Freissinet, C.; Bower, H.; Floyd, M.; Conrad, P.; Mahaffy, P.; Feldman, J.; Hurowitz, J.; Evans, J.; Anderson, M.; Jandura, L.; Brown, K.; Logan, C.; Kuhn, S.; Anderson, R.; Beegle, L.; Limonadi, D.; Rainen, R.; Umland, J.

    2013-01-01

    Polytetrafluoroethylene (PTFE or trade name: Teflon by Dupont Co.) has been detected in rocks drilled during terrestrial testing of the Mars Science Laboratory (MSL) drilling hardware. The PTFE in sediments is a wear product of the seals used in the Drill Bit Assemblies (DBAs). It is expected that the drill assembly on the MSL flight model will also shed Teflon particles into drilled samples. One of the primary goals of the Sample Analysis at Mars (SAM) instrument suite on MSL is to test for the presence of martian organics in samples. Complications introduced by the potential presence of PTFE in drilled samples to the SAM evolved gas analysis (EGA or pyrolysisquadrupole mass spectrometry, pyr-QMS) and pyrolysis- gas chromatography mass spectrometry (Pyr- GCMS) experiments was investigated.

  20. The Search for Nitrates on Mars by the Sample Analysis at Mars (SAM) Instrument

    NASA Technical Reports Server (NTRS)

    Navarro-Gonzalez, Rafael; Stern, Jennifer C.; Freissinet, Caroline; McKay, Chirstopher P.; Sutter, Brad; Archer, P. Douglas, Jr.; McAdam, Amy; Franz, Heather; Coll, Partice J.; Glavin, Daniel Patrick; Eigenbrode, Jennifer L.; Wong, Mike; Atreya, Sushiil K.; Wray, James J.; Steele, Andrew; Prats, Benito D.; Szopa, Cyril; Coscia, David; Teinturier, Samuel; Buch, Arnaud; Leshin, Laurie A.; Ming, Douglas W.; Conrad, Pamela Gales; Cabane, Michel; Mahaffy, Paul R.; Grotzinger, John P.

    2013-01-01

    Planetary models suggest that nitrogen was abundant in the early Martian atmosphere as N2 but it was lost by sputtering and photochemical loss to space, impact erosion, and chemical oxidation to nitrates. A nitrogen cycle may exist on Mars where nitrates, produced early in Mars' history, may have been later decomposed back into N2 by the current impact flux. Nitrates are a fundamental source of nitrogen for terrestrial microorganisms, and they have evolved metabolic pathways to perform both oxidation and reduction to drive a complete biological nitrogen cycle. Therefore, the characterization of nitrogen in Martian soils is important to assess habitability of the Martian environment, particularly with respect to the presence of nitrates. The only previous mission that was designed to search for soil nitrates was the Phoenix mission but N-containing species were not detected by TEGA or the MECA WCL. Nitrates have been tentatively identified in Nakhla meteorites, and if nitrogen was oxidized on Mars, this has important implications for the habitability potential of Mars. Here we report the results from the Sample Analysis at Mars (SAM) instrument suite aboard the Curiosity rover during the first year of surface operations in Gale Crater. Samples from the Rocknest aeolian deposit and sedimentary rocks (John Klein) were heated to approx 835degC under helium flow and the evolved gases were analyzed by MS and GC-MS. Two and possibly three peaks may be associated with the release of m/z 30 at temperatures ranging from 180degC to 500degC. M/z 30 has been tentatively identified as NO; other plausible contributions include CH2O and an isotopologue of CO, 12C18O. NO, CH2O, and CO may be reaction products of reagents (MTBSTFA/DMF) carried from Earth for the wet chemical derivatization experiments with SAM and/or derived from indigenous soil nitrogenated organics. Laboratory analyses indicate that it is also possible that <550degC evolved NO is produced via reaction of HCl with

  1. Health care allocation, public consultation and the concept of 'health'.

    PubMed

    Edgar, A

    1998-09-01

    By comparing models of market-based allocation with state-controlled national health care systems, it will be suggested that the way in which different communities deal with the allocation of health care is central to their expression of what might be called a moral self-understanding. That is to say that the provision of health care may be expected to be a focus of communal debate, not simply about morally acceptable and unacceptable actions, but also about the community's understanding of what it is that makes for a worthwhile and morally defensible human life. This moral self-understanding is seen to be entwined with the different concepts of 'health' that are implicit in different systems of allocation. In conclusion, it will be suggested that decisions concerning health care allocation must be made in response to a continuing, public and open debate about what health and health care mean to a particular community. PMID:10185170

  2. SAM Sample preparation and its impact on the detection of organic compounds on Mars

    NASA Astrophysics Data System (ADS)

    Buch, Arnaud; Szopa, Cyril; Coll, Patrice; Freissinet, Caroline; Glavin, Daniel; Belmahdi, Imene; François, Pascaline; Millan, Maeva; Eigenbrode, Jennifer; navarro, Rafael; Stern, Jennifer; Pinnick, Veronica; Coscia, David; Teinturier, Samuel; Miller, Kristen; Summons, Roger; Mahaffy, Paul

    2014-05-01

    The wet chemistry experiments on the Sample Analysis at Mars (SAM) [1] experiment in the Curiosity rover of the Mars Science Laboratory mission supports extraction of polar organic compounds from solid samples that improves their detection either by increasing the release of chemical species from solid sample matrices, or by changing their chemical structure to make compounds more amenable to gas chromatography mass spectrometry (GCMS). The wet chemistry approach provides an alternative to the nominal inert-thermal desorption/pyrolysis analytical protocol used by SAM [1] that is more aptly suited for polar components. SAM, includes two different wet chemistry experiments: MTBSTFA derivatization [2-3] and TMAH thermochemolysis [4]. Here we report on the nature of the MTBSTFA derivatization experiment on SAM, the detection of MTBSTFA products in the SAM evolved gas analysis and GCMS experiments, and the implications of this detection. Solid sample were heated up to approximately 840°C at a rate of 35°C/min under He flow. For GC analyses, the majority of the gas released was trapped on a hydrocarbon trap (Tenax®) over a specific temperature range. Adsorbed volatiles on the GC injection trap (IT) were then released into the GC column (CLP-MXT 30m x 0.25mm x 0.25µm) by rapidly heating the IT to 300°C. Then, in order better understand the part of compounds detected coming from internal reaction we have performed several lab experiments to mimic the SAM device. We have investigated the thermal degradation of Tenax®, and possible interaction with MTBSTFA and perchlorate in the SAM trap (Tenax®) to better constrain interpretations of SAM results on Mars. References: [1] Mahaffy, P. et al. (2012) Space Sci Rev, 170, 401-478. [2] Buch, A. et al. (2009) J chrom. A, 43, 143-151. [3] Stalport, F. et al. (2012) Planet. Space Sci. 67: 1-13 [4] Geffroy-Rodier, C. et al. (2009) JAAP, 85, 454-459. Acknowledgements: SAM-GC team acknowledges support from the French Space Agency

  3. Possible Detection of Nitrates on Mars by the Sample Analysis at Mars (SAM) Instrument

    NASA Technical Reports Server (NTRS)

    Navarro-Gonzalez, R.; Stern, J.; Sutter, B.; Archer, D.; McAdam, A.; Franz, H. B.; McKay, C. P.; Coll, P.; Cabane, M.; Ming, D. W.; Brunner, A. E.; Glavin, D.; Eigenbrode, J. L.; Jones, J. H.; Freissinet, C.; Leshin, L.; Wong, M.; Atreya, S.; Wray, J. J.; Steele, A.; Buch, A.; Prats, B. D.; Szopa, C.; Conrad, P.; Mahaffy, P.

    2013-01-01

    Planetary models suggest that nitrogen was abundant in the early Martian atmosphere as dinitrogen (N2). However, it has been lost by sputtering and photochemical loss to space [1, 2], impact erosion [3], and chemical oxidation to nitrates [4]. Nitrates, produced early in Mars history, are later decomposed back into N2 by the current impact flux [5], making possible a nitrogen cycle on Mars. It is estimated that a layer of about 3 m of pure NaNO3 should be distributed globally on Mars [5]. Nitrates are a fundamental source for nitrogen to terrestrial microorganisms. Therefore, the detection of soil nitrates is important to assess habitability in the Martian environment. The only previous mission that was designed to search for soil nitrates was the Phoenix mission but was unable to detect evolved N-containing species by TEGA and the MECA WCL [6]. Nitrates have been tentatively identified in the Nakhla meteorite [7]. The purpose of this work is to determine if nitrates were detected in first solid sample (Rocknest) in Gale Crater examined by the SAM instrument.

  4. Task allocation among multiple intelligent robots

    NASA Technical Reports Server (NTRS)

    Gasser, L.; Bekey, G.

    1987-01-01

    Researchers describe the design of a decentralized mechanism for allocating assembly tasks in a multiple robot assembly workstation. Currently, the approach focuses on distributed allocation to explore its feasibility and its potential for adaptability to changing circumstances, rather than for optimizing throughput. Individual greedy robots make their own local allocation decisions using both dynamic allocation policies which propagate through a network of allocation goals, and local static and dynamic constraints describing which robots are elibible for which assembly tasks. Global coherence is achieved by proper weighting of allocation pressures propagating through the assembly plan. Deadlock avoidance and synchronization is achieved using periodic reassessments of local allocation decisions, ageing of allocation goals, and short-term allocation locks on goals.

  5. Identification of trans-acting factors regulating SamDC expression in Oryza sativa.

    PubMed

    Basu, Supratim; Roychoudhury, Aryadeep; Sengupta, Dibyendu N

    2014-03-01

    Abiotic stress affects the growth and productivity of crop plants; to cope with the adverse environmental conditions, plants have developed efficient defense machinery comprising of antioxidants like phenolics and flavonoids, and osmolytes like polyamines. SamDC is a key enzyme in the polyamine biosynthesis pathway in plants. In our present communication we have done in silico analysis of the promoter region of SamDC to look for the presence of different cis-regulatory elements contributing to its expression. Based on the presence of different cis-regulatory elements we completed comparative analysis of SamDC gene expression in rice lamina of IR-29 and Nonabokra by qPCR in response to the abiotic stress treatments of salinity, drought, cold and the biotic stress treatments of ABA and light. Additionally, to explore the role of the cis-regulatory elements in regulating the expression of SamDC gene in plants we comparatively analyzed the binding of rice nuclear proteins prepared from IR-29 and Nonabokra undergoing various stress treatments. The intensity of the complex formed was low and inducible in IR-29 in contrast to Nonabokra. Southwestern blot analysis helped in predicting the size of the trans-acting factors binding to these cis-elements. To our knowledge this is the first report on the comprehensive analysis of SamDC gene expression in rice and identification of the trans-acting factors regulating its expression. PMID:24530223

  6. Carbon–sulfur bond-forming reaction catalysed by the radical SAM enzyme HydE

    NASA Astrophysics Data System (ADS)

    Rohac, Roman; Amara, Patricia; Benjdia, Alhosna; Martin, Lydie; Ruffié, Pauline; Favier, Adrien; Berteau, Olivier; Mouesca, Jean-Marie; Fontecilla-Camps, Juan C.; Nicolet, Yvain

    2016-05-01

    Carbon–sulfur bond formation at aliphatic positions is a challenging reaction that is performed efficiently by radical S-adenosyl-L-methionine (SAM) enzymes. Here we report that 1,3-thiazolidines can act as ligands and substrates for the radical SAM enzyme HydE, which is involved in the assembly of the active site of [FeFe]-hydrogenase. Using X-ray crystallography, in vitro assays and NMR spectroscopy we identified a radical-based reaction mechanism that is best described as the formation of a C-centred radical that concomitantly attacks the sulfur atom of a thioether. To the best of our knowledge, this is the first example of a radical SAM enzyme that reacts directly on a sulfur atom instead of abstracting a hydrogen atom. Using theoretical calculations based on our high-resolution structures we followed the evolution of the electronic structure from SAM through to the formation of S-adenosyl-L-cysteine. Our results suggest that, at least in this case, the widely proposed and highly reactive 5‧-deoxyadenosyl radical species that triggers the reaction in radical SAM enzymes is not an isolable intermediate.

  7. Characterization of a S-adenosyl-l-methionine (SAM)-accumulating strain of Scheffersomyces stipitis.

    PubMed

    Križanović, Stela; Butorac, Ana; Mrvčić, Jasna; Krpan, Maja; Cindrić, Mario; Bačun-Družina, Višnja; Stanzer, Damir

    2015-06-01

    S-adenosyl-l-methionine (SAM) is an important molecule in the cellular metabolism of mammals. In this study, we examined several of the physiological characteristics of a SAM-accumulating strain of the yeast Scheffersomyces stipitis (M12), including SAM production, ergosterol content, and ethanol tolerance. S. stipitis M12 accumulated up to 52.48 mg SAM/g dry cell weight. Proteome analyses showed that the disruption of C-24 methylation in ergosterol biosynthesis, a step mediated by C-24 sterol methyltransferase (Erg6p), results in greater SAM accumulation by S. stipitis M12 compared to the wild-type strain. A comparative proteome-wide analysis identified 25 proteins that were differentially expressed by S. stipitis M12. These proteins are involved in ribosome biogenesis, translation, the stress response, ubiquitin-dependent catabolic processes, the cell cycle, ethanol tolerance, posttranslational modification, peroxisomal membrane stability, epigenetic regulation, the actin cytoskeleton and cell morphology, iron and copper homeostasis, cell signaling, and energy metabolism. PMID:26496619

  8. Oxygen Attachment on Alkanethiolate SAMs Induced by Low-Energy Electron Irradiation

    PubMed Central

    Massey, Sylvain; Bass, Andrew D.; Steffenhagen, Marie; Sanche, Léon

    2013-01-01

    Reactions of 18O2 with self-assembled monolayer (SAM) films of 1-dodecanethiol, 1-octadecanethiol, 1-butanethiol, and benzyl mercaptan chemisorbed on gold, were studied by the electron stimulated desorption (ESD) of anionic fragments over the incident electron energy range 2–20 eV. Dosing the SAMs with 18O2 at 50 K, results in the ESD of 18O− and 18OH−. Electron irradiation of samples prior to 18O2 deposition demonstrates that intensity of subsequent 18O− and 18OH− desorption signals increase with electron fluence and that absent electron pre-irradiation, no 18O− and 18OH− ESD signals are observed, since oxygen is unable to bind to the SAMs. A minimum incident electron energy of 6–7 eV is required to initiate the binding of 18O2 to the SAMs. O2 binding is proposed to proceed by the formation of CHx−1• radicals via resonant dissociative electron attachment and non-resonant C–H dissociation processes. The weaker signals of 18O− and 18OH− from short-chain SAMs are related to the latter’s resistance to electron induced damage, due to the charge-image dipole quenching and electron delocalization. Comparison between the present results and those for DNA oligonucleotides self-assembled on Au [Mirsaleh-Kohan, N. et al. J. Chem. Phys. 2012, 136, 235104] indicates that the oxygen binding mechanism is common to both systems. PMID:23537075

  9. Carbon-sulfur bond-forming reaction catalysed by the radical SAM enzyme HydE.

    PubMed

    Rohac, Roman; Amara, Patricia; Benjdia, Alhosna; Martin, Lydie; Ruffié, Pauline; Favier, Adrien; Berteau, Olivier; Mouesca, Jean-Marie; Fontecilla-Camps, Juan C; Nicolet, Yvain

    2016-05-01

    Carbon-sulfur bond formation at aliphatic positions is a challenging reaction that is performed efficiently by radical S-adenosyl-L-methionine (SAM) enzymes. Here we report that 1,3-thiazolidines can act as ligands and substrates for the radical SAM enzyme HydE, which is involved in the assembly of the active site of [FeFe]-hydrogenase. Using X-ray crystallography, in vitro assays and NMR spectroscopy we identified a radical-based reaction mechanism that is best described as the formation of a C-centred radical that concomitantly attacks the sulfur atom of a thioether. To the best of our knowledge, this is the first example of a radical SAM enzyme that reacts directly on a sulfur atom instead of abstracting a hydrogen atom. Using theoretical calculations based on our high-resolution structures we followed the evolution of the electronic structure from SAM through to the formation of S-adenosyl-L-cysteine. Our results suggest that, at least in this case, the widely proposed and highly reactive 5'-deoxyadenosyl radical species that triggers the reaction in radical SAM enzymes is not an isolable intermediate. PMID:27102684

  10. XPS and ToF-SIMS Investigation of α-Helical and β-Strand Peptide Adsorption onto SAMs

    PubMed Central

    Apte, Julia S.; Collier, Galen; Latour, Robert A.; Gamble, Lara J.; Castner, David G.

    2009-01-01

    14-mer α-helix and a 15-mer β-strand oligopeptides composed of leucine (L) and lysine (K) were used to investigate peptide adsorption and orientation onto well-defined methyl and carboxylic acid terminated self-assembled monolayer (SAM) surfaces with X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). XPS showed both peptides reached monolayer thickness on both SAMs, but significantly higher solution concentrations were required to reach this coverage on the methyl SAMs. This shows that the peptides adsorb more strongly onto the carboxyl-terminated SAMs. The excess oxygen detected by XPS and the H3O+ signal detected by ToF-SIMS for the SAMs with adsorbed peptides indicated that water molecules are associated with the adsorbed peptides, even under ultra-high vacuum conditions. Changes in the amount of L and K fragments detected by ToF-SIMS indicate the β-strand oriented differently on the two SAMs. The L side-chains were preferentially associated with the methyl-terminated SAM and the K side-chains were preferentially associated with the carboxyl SAM. In contrast, little change in the ToF-SIMS K/L ratio was observed for the α-helix peptide absorbed on the two SAMs, indicating ToF-SIMS was not as sensitive to orientation of the α-helix peptide. PMID:19891457

  11. Time Allocation at Home and Achievement in School.

    ERIC Educational Resources Information Center

    Levine, Victor

    This paper presents an economic model of the relationship between time allocated to learning activities at home and achievement in school. The model is contrasted to four alternative models of the home-school relationship. Data from a 1975 survey of the parents of 887 elementary school children from one New York State school district are used to…

  12. Nonlinear optical studies of self-assembled monolayers (SAM) silica-SAM-water interface probed with second harmonic generation

    NASA Astrophysics Data System (ADS)

    James, Kenneth Edward

    Second harmonic generation (SHG) is a successful and widely used technique for the study of surfaces and surface phenomena. We present a novel technique using second harmonic generation from oriented water molecules in the Gouy-Chapman diffuse layer at the alkylsiloxane and biomolecular self assembled monolayer (SAM) interface with water to measure distance between the solid surface and the average location of the oriented water in the diffuse layer. This distance is manifest in the SHG angular dependence profile from the relative phases of the second harmonic light generated at the diffuse layer and at the solid surface. Distances of one nanometer can be distinguished. Values for the diffuse layer potential, diffuse layer decay length, magnitude and phase of the nonlinear susceptibility were obtained. This in situ probe is universally applicable for organic adsorbates which in general will push the diffuse layer away from the solid surface. The organic layer thickness can be used to obtain the adsorption fraction. From this and an understanding of the likely chemistry, the orientation of the molecules can be inferred. We have demonstrated this technique on three molecular systems: hydrophobic self assembled monolayers of methoxysilane molecules of varying hydrocarbon chain length, self assembled monolayers of streptavidin glycoproteins and the combined streptavidin-biotinylated antibody monolayer. In the methoxysilane monolayers a relationship between hydrophobicity and molecular orientation was observed. The thickness of the streptavidin monolayer was determined to be 5.6 nm. This is strikingly close to the length of the of the streptavidin molecule which implies a close packed monolayer of streptavidin molecules. The average height of the antibodies was determined to be 10.9 nm or about two thirds the height of an antibody molecule. This too confirms a monolayer and allows for good approximation of surface coverage. This method does nothing to disturb or alter

  13. Resource Allocation: A Participatory Process.

    ERIC Educational Resources Information Center

    Reid, Alban E.

    Whether a participatory process for resource allocation in a public community college setting occurs depends upon several key factors: (1) the leadership style of the institutional chief executive officer; (2) the administrative organizational structure of the institution; (3) the relationship which exists between and among members of the various…

  14. Report on Tribal Priority Allocations.

    ERIC Educational Resources Information Center

    Bureau of Indian Affairs (Dept. of Interior), Washington, DC.

    As part of Bureau of Indian Affairs (BIA) funding, Tribal Priority Allocations (TPA) are the principal source of funds for tribal governments and agency offices at the reservation level. According to their unique needs and circumstances, tribes may prioritize funding among eight general categories: government, human services, education, public…

  15. Regulating nutrient allocation in plants

    DOEpatents

    Udvardi, Michael; Yang, Jiading; Worley, Eric

    2014-12-09

    The invention provides coding and promoter sequences for a VS-1 and AP-2 gene, which affects the developmental process of senescence in plants. Vectors, transgenic plants, seeds, and host cells comprising heterologous VS-1 and AP-2 genes are also provided. Additionally provided are methods of altering nutrient allocation and composition in a plant using the VS-1 and AP-2 genes.

  16. Administrators' Decisions about Resource Allocation

    ERIC Educational Resources Information Center

    Knight, William E.; Folkins, John W.; Hakel, Milton D.; Kennell, Richard P.

    2011-01-01

    Do academic administrators make decisions about resource allocation differently depending on the discipline receiving the funding? Does an administrator's academic identity influence these decisions? This study explored those questions with a sample of 1,690 academic administrators at doctoral-research universities. Participants used fictional…

  17. Allocating Resources to Enhance Resilience, with Application to Superstorm Sandy and an Electric Utility.

    PubMed

    MacKenzie, Cameron A; Zobel, Christopher W

    2016-04-01

    This article constructs a framework to help a decisionmaker allocate resources to increase his or her organization's resilience to a system disruption, where resilience is measured as a function of the average loss per unit time and the time needed to recover full functionality. Enhancing resilience prior to a disruption involves allocating resources from a fixed budget to reduce the value of one or both of these characteristics. We first look at characterizing the optimal resource allocations associated with several standard allocation functions. Because the resources are being allocated before the disruption, however, the initial loss and recovery time may not be known with certainty. We thus also apply the optimal resource allocation model for resilience to three models of uncertain disruptions: (1) independent probabilities, (2) dependent probabilities, and (3) unknown probabilities. The optimization model is applied to an example of increasing the resilience of an electric power network following Superstorm Sandy. PMID:26332406

  18. Distributed processing and analysis of physics data in the D0 SAM system at Fermilab

    SciTech Connect

    Igor V. Terekhov

    2001-08-30

    SAM (Sequential Access through Meta-data) is the data access system for the D0 high energy physics (HEP) experiment at Fermilab. The system is being developed and used to handle the Petabyte-scale experiment data. The D0 applications, like virtually all HEP applications, are data-intensive, which poses special problems for the data management and job control facilities in the distributed environment. The fundamental problem is to bring the user applications and the data together, and SAM attacks the problems from both sides. First, we describe how the system moves the data through the distributed disk cache. Second, we describe how SAM interacts with the batch system to synchronize parallel user jobs with the data availability. All the design solutions herein have been implemented in a real system that handles the mission-critical data of the D0 experiment; thus, we present our work from the standpoint of real experience.

  19. Detection of Organics at Mars: How Wet Chemistry Onboard SAM Helps

    NASA Technical Reports Server (NTRS)

    Buch, A.; Freissinet, Caroline; Szopa, C.; Glavin, D.; Coll, P.; Cabane, M.; Eigenbrode, J.; Navarro-Gonzalez, R.; Coscia, D.; Teinturier, S.; Mahaffy, P.

    2013-01-01

    For the first time in the history of space exploration, a mission of interest to astrobiology could be able to analyze refractory organic compounds in the soil of Mars. Wet chemistry experiment allow organic components to be altered in such a way that improves there detection either by releasing the compounds from sample matricies or by changing the chemical structure to be amenable to analytical conditions. The latter is particular important when polar compounds are present. Sample Analysis at Mars (SAM), on the Curiosity rover of the Mars Science Laboratory mission, has onboard two wet chemistry experiments: derivatization and thermochemolysis. Here we report on the nature of the MTBSTFA derivatization experiment on SAM, the detection of MTBSTFA in initial SAM results, and the implications of this detection.

  20. The crystal structure of a novel SAM-dependent methyltransferase PH1915 from Pyrococcus horikoshii.

    SciTech Connect

    Sun, W.; Xu, X.; Pavlova, M.; Edwards, A.; Joachimiak, A.; Savchenko, A.; Christendat, D.; Biosciences Division; Univ. of Toronto; Univ. Health Network

    2005-01-01

    The S-adenosyl-L-methionine (SAM)-dependent methyltransferases represent a diverse and biologically important class of enzymes. These enzymes utilize the ubiquitous methyl donor SAM as a cofactor to methylate proteins, small molecules, lipids, and nucleic acids. Here we present the crystal structure of PH1915 from Pyrococcus horikoshii OT3, a predicted SAM-dependent methyltransferase. This protein belongs to the Cluster of Orthologous Group 1092, and the presented crystal structure is the first representative structure of this protein family. Based on sequence and 3D structure analysis, we have made valuable functional insights that will facilitate further studies for characterizing this group of proteins. Specifically, we propose that PH1915 and its orthologs are rRNA- or tRNA-specific methyltransferases.

  1. SPASM and Twitch Domains in S-Adenosylmethionine (SAM) Radical Enzymes*

    PubMed Central

    Grell, Tsehai A. J.; Goldman, Peter J.; Drennan, Catherine L.

    2015-01-01

    S-Adenosylmethionine (SAM, also known as AdoMet) radical enzymes use SAM and a [4Fe-4S] cluster to catalyze a diverse array of reactions. They adopt a partial triose-phosphate isomerase (TIM) barrel fold with N- and C-terminal extensions that tailor the structure of the enzyme to its specific function. One extension, termed a SPASM domain, binds two auxiliary [4Fe-4S] clusters and is present within peptide-modifying enzymes. The first structure of a SPASM-containing enzyme, anaerobic sulfatase-maturating enzyme (anSME), revealed unexpected similarities to two non-SPASM proteins, butirosin biosynthetic enzyme 2-deoxy-scyllo-inosamine dehydrogenase (BtrN) and molybdenum cofactor biosynthetic enzyme (MoaA). The latter two enzymes bind one auxiliary cluster and exhibit a partial SPASM motif, coined a Twitch domain. Here we review the structure and function of auxiliary cluster domains within the SAM radical enzyme superfamily. PMID:25477505

  2. Analytic hierarchy process (AHP) as a tool in asset allocation

    NASA Astrophysics Data System (ADS)

    Zainol Abidin, Siti Nazifah; Mohd Jaffar, Maheran

    2013-04-01

    Allocation capital investment into different assets is the best way to balance the risk and reward. This can prevent from losing big amount of money. Thus, the aim of this paper is to help investors in making wise investment decision in asset allocation. This paper proposes modifying and adapting Analytic Hierarchy Process (AHP) model. The AHP model is widely used in various fields of study that are related in decision making. The results of the case studies show that the proposed model can categorize stocks and determine the portion of capital investment. Hence, it can assist investors in decision making process and reduce the risk of loss in stock market investment.

  3. The survey of autobiographical memory (SAM): a novel measure of trait mnemonics in everyday life.

    PubMed

    Palombo, Daniela J; Williams, Lynne J; Abdi, Hervé; Levine, Brian

    2013-06-01

    Compared to the abundance of laboratory-based memory tasks, few measures exist to assess self-reported memory function. This need is particularly important for naturalistic mnemonic capacities, such as autobiographical memory (recall of events and facts from one's past), because it is difficult to reliably assess in the laboratory. Furthermore, naturalistic mnemonic capacities may show stable individual differences that evade the constraints of laboratory testing. The Survey of Autobiographical Memory (SAM) was designed to assess such trait mnemonics, or the dimensional characterization of self-reported mnemonic characteristics. The SAM comprises items assessing self-reported episodic autobiographical, semantic, and spatial memory, as well as future prospection. In a large sample of healthy young adults, the latent dimensional structure of the SAM was characterized with multiple correspondence analysis (MCA). This analysis revealed dimensions corresponding to general mnemonic abilities (i.e., good vs poor memory across subtypes), spatial memory, and future prospection. While episodic and semantic items did not separate in this data-driven analysis, these categories did show expected dissociations in relation to depression history and to laboratory-based measures of recollection. Remote spatial memory as assessed by the SAM showed the expected advantage for males over females. Spatial memory was also related to autobiographical memory performance. Brief versions of the SAM are provided for efficient research applications. Individual differences in memory function are likely related to other health-related factors, including personality, psychopathology, dementia risk, brain structure and function, and genotype. In conjunction with laboratory or performance based assessments, the SAM can provide a useful measure of naturalistic self-report trait mnemonics for probing these relationships. PMID:23063319

  4. Data handling with SAM and art at the NOνA experiment

    NASA Astrophysics Data System (ADS)

    Aurisano, A.; Backhouse, C.; Davies, G. S.; Illingworth, R.; Mayer, N.; Mengel, M.; Norman, A.; Rocco, D.; Zirnstein, J.

    2015-12-01

    During operations, NOvA produces between 5,000 and 7,000 raw files per day with peaks in excess of 12,000. These files must be processed in several stages to produce fully calibrated and reconstructed analysis files. In addition, many simulated neutrino interactions must be produced and processed through the same stages as data. To accommodate the large volume of data and Monte Carlo, production must be possible both on the Fermilab grid and on off-site farms, such as the ones accessible through the Open Science Grid. To handle the challenge of cataloging these files and to facilitate their off-line processing, we have adopted the SAM system developed at Fermilab. SAM indexes files according to metadata, keeps track of each file's physical locations, provides dataset management facilities, and facilitates data transfer to off-site grids. To integrate SAM with Fermilab's art software framework and the NOvA production workflow, we have developed methods to embed metadata into our configuration files, art files, and standalone ROOT files. A module in the art framework propagates the embedded information from configuration files into art files, and from input art files to output art files, allowing us to maintain a complete processing history within our files. Embedding metadata in configuration files also allows configuration files indexed in SAM to be used as inputs to Monte Carlo production jobs. Further, SAM keeps track of the input files used to create each output file. Parentage information enables the construction of self-draining datasets which have become the primary production paradigm used at NOvA. In this paper we will present an overview of SAM at NOvA and how it has transformed the file production framework used by the experiment.

  5. Data handling with SAM and art at the NOvA experiment

    DOE PAGESBeta

    Aurisano, A.; Backhouse, C.; Davies, G. S.; Illingworth, R.; Mayer, N.; Mengel, M.; Norman, A.; Rocco, D.; Zirnstein, J.

    2015-12-23

    During operations, NOvA produces between 5,000 and 7,000 raw files per day with peaks in excess of 12,000. These files must be processed in several stages to produce fully calibrated and reconstructed analysis files. In addition, many simulated neutrino interactions must be produced and processed through the same stages as data. To accommodate the large volume of data and Monte Carlo, production must be possible both on the Fermilab grid and on off-site farms, such as the ones accessible through the Open Science Grid. To handle the challenge of cataloging these files and to facilitate their off-line processing, we havemore » adopted the SAM system developed at Fermilab. SAM indexes files according to metadata, keeps track of each file's physical locations, provides dataset management facilities, and facilitates data transfer to off-site grids. To integrate SAM with Fermilab's art software framework and the NOvA production workflow, we have developed methods to embed metadata into our configuration files, art files, and standalone ROOT files. A module in the art framework propagates the embedded information from configuration files into art files, and from input art files to output art files, allowing us to maintain a complete processing history within our files. Embedding metadata in configuration files also allows configuration files indexed in SAM to be used as inputs to Monte Carlo production jobs. Further, SAM keeps track of the input files used to create each output file. Parentage information enables the construction of self-draining datasets which have become the primary production paradigm used at NOvA. In this study we will present an overview of SAM at NOvA and how it has transformed the file production framework used by the experiment.« less

  6. Searching for Reduced Carbon on the Surface of Mars: The SAM Combustion Experiment

    NASA Technical Reports Server (NTRS)

    Stern, J. C.; Malespin, C. A.; Mahaffy, P. R.; Webster, C. R.; Eigenbrode, J. L.; Archer, P. D., Jr.; Brunner, A. E.; Freissinet, C.; Franz, H. B.; Glavin, D. P.; Graham, H. V.; McAdam, A. C.; Ming, D. W.; Navarro-Gonzalez, R.; Niles, P. B.; Steele, A.; Sutter, B.; Trainer, M. G.

    2014-01-01

    The search for reduced carbon has been a major focus of past and present missions to Mars. Thermal evolved gas analysis was used by the Viking and Phoenix landers and is currently in use by the Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) to characterize volatiles evolved from solid samples, including those associated with reduced organic species. SAM has the additional capability to perform a combustion experiment, in which a sample of Mars regolith is heated in the presence of oxygen and the composition of the evolved gases is measured using quadrupole mass spectrometry (QMS) and tunable laser spectrometry (TLS) [1]. Organics detection on the Martian surface has been complicated by oxidation and destruction during heating by soil oxidants [2], including oxychlorine compounds, and terrestrial organics in the SAM background contributed by one of the SAM wet chemistry reagents MTBSTFA (N-Methyl-N-tertbutyldimethylsilyl- trifluoroacetamide) [3,4]. Thermal Evolved Gas Analysis (TEGA) results from Phoenix show a mid temperature CO2 release between 400 C - 680 C speculated to be carbonate, CO2 adsorbed to grains, or combustion of organics by soil oxidants [5]. Low temperature CO2 evolutions (approx. 200 C - 400 C) were also present at all three sites in Gale Crater where SAM Evolved Gas Analysis (EGA) was performed, and potential sources include combustion of terrestrial organics from SAM, as well as combustion and/or decarboxylation either indigenous martian or exogenous organic carbon [4,6]. By performing an experiment to intentionally combust all reduced materials in the sample, we hope to compare the bulk abundance of CO2 and other oxidized species evolved by combustion to that evolved during an EGA experiment to estimate how much CO2 could be contributed by reduced carbon sources. In addition, C, O, and H isotopic compositions of CO2 and H2O measured by TLS can contribute information regarding the potential sources of these

  7. In Situ Analysis of Mars Soil and Rocks Sample with the Sam Gcms Instrumentation Onboard Curiosity : Interpretation and Comparison of Measurements Done during the First Martian Year of Curiosity on Mars

    NASA Astrophysics Data System (ADS)

    Szopa, C.; Coll, P. J.; Cabane, M.; Buch, A.; Coscia, D.; Millan, M.; Francois, P.; Belmahadi, I.; Teinturier, S.; Navarro-Gonzalez, R.; Glavin, D. P.; Freissinet, C.; Steele, A.; Eigenbrode, J. L.; Mahaffy, P. R.

    2014-12-01

    The characterisation of the chemical and mineralogical composition of solid surface samples collected with the Curiosity rover is a primary objective of the SAM experiment. These data should provide essential clues on the past habitability of Gale crater. Amongst the SAM suite of instruments [1], SAM-GC (Gas Chromatograph) is devoted to identify and quantify volatiles evolved from the thermal (heating up to about 900°C)/chemical (derivatization procedure) treatment of any soil sample collected by the Curiosity rover. With the aim to search for potential organic molecules outgassed from the samples, SAM-GC analytical channels composed of thermal-desorption injector, and a MXT-CLP or a MXT-Q chromatographic column was chosen to achieve all the measurements done up today, with the aim to separate of a wide range of volatile inorganic and organic molecules. Four solid samples have been analyzed with GCMS, one sand sample collected at the Rocknest site, two rock samples (John Klein and Cumberland respectively) collected at the Yellowknife Bay site using the Curiosity driller, and one rock sample collected at the Kimberly site. All the measurements were successful and they produced complex chromatograms with both detectors used for SAM GC, i.e. a thermal conductivity detector and the SAM quandrupole mass spectrometer. Their interpretation already revealed the presence of an oxychlorine phase present in the sample which is at the origin of chlorohydrocarbons clearly identified [2] but this represents only a fraction of the GCMS signal recorded [3,4]. This work presents a systematic comparison of the GCMS measurements done for the different samples collected, supported by reference data obtained in laboratory with different spare models of the gas chromatograph, with the aim to bring new elements of interpretation of the SAM measurements. References: [1] Mahaffy, P. et al. (2012) Space Sci Rev, 170, 401-478. [2] Glavin, D. et al. (2013), JGR. [3] Leshin L. et al. (2013

  8. The Combustion Experiment on the Sample Analysis at Mars (SAM) Instrument Suite on the Curiosity Rover

    NASA Technical Reports Server (NTRS)

    Stern, J. C.; Malespin, C. A.; Eigenbrode, J.; Graham, H. V.; Archer, P. D.; Brunner, A.; Freissinet, C.; Franz, H. B.; Fuentes, J.; Glavin, D. P.; Mahaffy, P. R.; McAdam, A. C.; Ming, D. W.; Niles, P. B.; Steele, A.

    2014-01-01

    The combustion experiment on the Sample Analysis at Mars (SAM) suite on Curiosity will heat a sample of Mars regolith in the presence of oxygen and measure composition of the evolved gases using quadrupole mass spectrometry (QMS) and tunable laser spectrometry (TLS). QMS will enable detection of combustion products such as CO, CO2, NO, and other oxidized species, while TLS will enable precision measurements of the abundance and carbon isotopic composition (delta C-13) of the evolved CO2 and hydrogen isotopic composition (delta D) of H2O. SAM will perform a two-step combustion to isolate combustible materials below approx. 550 C and above approx. 550 C.

  9. Mechanistic studies of the radical SAM enzyme spore photoproduct lyase (SPL).

    PubMed

    Li, Lei

    2012-11-01

    Spore photoproduct lyase (SPL) repairs a special thymine dimer 5-thyminyl-5,6-dihydrothymine, which is commonly called spore photoproduct or SP at the bacterial early germination phase. SP is the exclusive DNA photo-damage product in bacterial endospores; its generation and swift repair by SPL are responsible for the spores' extremely high UV resistance. The early in vivo studies suggested that SPL utilizes a direct reversal strategy to repair the SP in the absence of light. The research in the past decade further established SPL as a radical SAM enzyme, which utilizes a tri-cysteine CXXXCXXC motif to harbor a [4Fe-4S] cluster. At the 1+ oxidation state, the cluster provides an electron to the S-adenosylmethionine (SAM), which binds to the cluster in a bidentate manner as the fourth and fifth ligands, to reductively cleave the CS bond associated with the sulfonium ion in SAM, generating a reactive 5'-deoxyadenosyl (5'-dA) radical. This 5'-dA radical abstracts the proR hydrogen atom from the C6 carbon of SP to initiate the repair process; the resulting SP radical subsequently fragments to generate a putative thymine methyl radical, which accepts a back-donated H atom to yield the repaired TpT. SAM is suggested to be regenerated at the end of each catalytic cycle; and only a catalytic amount of SAM is needed in the SPL reaction. The H atom source for the back donation step is suggested to be a cysteine residue (C141 in Bacillus subtilis SPL), and the H-atom transfer reaction leaves a thiyl radical behind on the protein. This thiyl radical thus must participate in the SAM regeneration process; however how the thiyl radical abstracts an H atom from the 5'-dA to regenerate SAM is unknown. This paper reviews and discusses the history and the latest progress in the mechanistic elucidation of SPL. Despite some recent breakthroughs, more questions are raised in the mechanistic understanding of this intriguing DNA repair enzyme. This article is part of a Special Issue

  10. Unsupervised classification of Space Acceleration Measurement System (SAMS) data using ART2-A

    NASA Technical Reports Server (NTRS)

    Smith, A. D.; Sinha, A.

    1999-01-01

    The Space Acceleration Measurement System (SAMS) has been developed by NASA to monitor the microgravity acceleration environment aboard the space shuttle. The amount of data collected by a SAMS unit during a shuttle mission is in the several gigabytes range. Adaptive Resonance Theory 2-A (ART2-A), an unsupervised neural network, has been used to cluster these data and to develop cause and effect relationships among disturbances and the acceleration environment. Using input patterns formed on the basis of power spectral densities (psd), data collected from two missions, STS-050 and STS-057, have been clustered.

  11. The nucleation and growth of calcium oxalate monohydrate on self- assembled monolayers (SAMs)

    SciTech Connect

    Campbell, A.A.; Tarasevich, B.J.; Graff, G.L.; Fryxell, G.E.; Rieke, P.C.

    1992-05-01

    A physical chemical approach was used to study calcium oxalate monohydrate (COM) nucleation and growth on various organic interfaces. Self-assembling monolayers (SAMs), containing derivatized organic functional groups, were designed to mimic various amino acid residues present in both urine and stone matrix macromolecules. Derivatized surfaces include SAMs with terminal methyl, bromo, imidazole, and thiazolidine-carboxylic acid functional groups. Pronounced differences in COM deposition were observed for the various interfaces with the imidazole and thiazolidine surfaces having the greatest effect and the methyl and bromo groups having little or no nucleating potential.

  12. Distributed data access and resource management in the D0 SAM system

    SciTech Connect

    Igor V Terekhov; Ruth Pordes; Victoria White et al.

    2001-06-26

    SAM (Sequential Access through Meta-data) is the data access and job management system for the D0 high energy physics experiment at Fermilab. The SAM system is being developed and used to handle the Petabyte-scale experiment data, accessed by hundreds of D0 collaborators scattered around the world. In this paper, we present solutions to some of the distributed data processing problems from the perspective of real experience dealing with mission-critical data. We concentrate on the distributed disk caching, resource management and job control. The system has elements of the Grid Computing and has features applicable to data-intensive computing in general.

  13. Mineral classification map using MF and SAM techniques: A case study in the Nohwa Island, Korea

    SciTech Connect

    Son, Young-Sun; Yoon, Wang-Jung

    2015-03-10

    The purpose of this study is to map pyprophyllite distribution at surface of the Nohwa deposit, Korea by using Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER) data. For this, combined Spectral Angle Mapper (SAM), and Matched Filtering (MF) technique based on mathematical algorithm was applied. The regional distribution of high-grade and low-grade pyrophyllite in the Nohwa deposit area could be differentiated by this method. The results of this study show that ASTER data analysis using combination of SAM and MF techniques will assist in exploration of pyrophyllite at the exposed surface.

  14. A unified framework for optimal multiple video object bit allocation

    NASA Astrophysics Data System (ADS)

    Chen, Zhenzhong; Ngan, King Ngi

    2005-07-01

    MPEG-4 supports object-level video coding. It is a challenge to design an optimal bit allocation strategy which considers not only how to distribute bits among multiple video objects (MVO's) but also how to achieve optimization between the texture and shape information. In this paper, we present a uniform framework for optimal multiple video object bit allocation in MPEG-4. We combine the rate-distortion (R-D) models for the texture and shape information of arbitrarily shaped video objects to develop the joint texture-shape rate-distortion models. The dynamic programming (DP) technique is applied to optimize the bit allocation for the multiple video objects. The simulation results demonstrate that the proposed joint texture-shape optimization algorithm outperforms the MPEG-4 verification model on the decoded picture quality.

  15. 23 CFR 660.107 - Allocations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Allocations. 660.107 Section 660.107 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS SPECIAL PROGRAMS (DIRECT FEDERAL) Forest Highways § 660.107 Allocations. On October 1 of each fiscal year, the FHWA will allocate 66 percent of Public Lands...

  16. 15 CFR 923.110 - Allocation formula.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Allocation formula. 923.110 Section... Grants § 923.110 Allocation formula. (a) As required by subsection 306(a), the Secretary may make grants...) Allocation formula factors and weighting. Each State eligible to receive a financial assistance award...

  17. 10 CFR 455.31 - Allocation formulas.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Allocation formulas. 455.31 Section 455.31 Energy... § 455.31 Allocation formulas. (a) Financial assistance for conducting technical assistance programs for... this section. (c) The allocation factor (K) shall be determined by the formula: EC14NO91.086 where,...

  18. 24 CFR 574.130 - Formula allocations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Formula allocations. 574.130... URBAN DEVELOPMENT COMMUNITY FACILITIES HOUSING OPPORTUNITIES FOR PERSONS WITH AIDS Formula Entitlements § 574.130 Formula allocations. (a) Data sources. HUD will allocate funds based on the number of cases...

  19. 45 CFR 1355.57 - Cost allocation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Cost allocation. 1355.57 Section 1355.57 Public... MAINTENANCE PAYMENTS, ADOPTION ASSISTANCE, AND CHILD AND FAMILY SERVICES GENERAL § 1355.57 Cost allocation. (a... maintenance payments or adoption assistance payments may be made under the State plan. (b) Cost allocation...

  20. 45 CFR 400.13 - Cost allocation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Cost allocation. 400.13 Section 400.13 Public... for Refugee Resettlement Award of Grants to States § 400.13 Cost allocation. (a) A State must allocate... management of the State's refugee program (e.g., development of the State plan, overall program...

  1. 45 CFR 400.13 - Cost allocation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 2 2011-10-01 2011-10-01 false Cost allocation. 400.13 Section 400.13 Public... for Refugee Resettlement Award of Grants to States § 400.13 Cost allocation. (a) A State must allocate... management of the State's refugee program (e.g., development of the State plan, overall program...

  2. 45 CFR 1355.57 - Cost allocation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false Cost allocation. 1355.57 Section 1355.57 Public... MAINTENANCE PAYMENTS, ADOPTION ASSISTANCE, AND CHILD AND FAMILY SERVICES GENERAL § 1355.57 Cost allocation. (a... maintenance payments or adoption assistance payments may be made under the State plan. (b) Cost allocation...

  3. 24 CFR 92.50 - Formula allocation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 1 2014-04-01 2014-04-01 false Formula allocation. 92.50 Section 92.50 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development HOME INVESTMENT PARTNERSHIPS PROGRAM Allocation Formula § 92.50 Formula allocation....

  4. 24 CFR 92.50 - Formula allocation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 1 2013-04-01 2013-04-01 false Formula allocation. 92.50 Section 92.50 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development HOME INVESTMENT PARTNERSHIPS PROGRAM Allocation Formula § 92.50 Formula allocation....

  5. 24 CFR 92.50 - Formula allocation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 1 2012-04-01 2012-04-01 false Formula allocation. 92.50 Section 92.50 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development HOME INVESTMENT PARTNERSHIPS PROGRAM Allocation Formula § 92.50 Formula allocation....

  6. 45 CFR 98.55 - Cost allocation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 1 2014-10-01 2014-10-01 false Cost allocation. 98.55 Section 98.55 Public... of Child Care and Development Funds § 98.55 Cost allocation. (a) The Lead Agency and subgrantees shall keep on file cost allocation plans or indirect cost agreements, as appropriate, that have...

  7. 45 CFR 98.55 - Cost allocation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Cost allocation. 98.55 Section 98.55 Public... of Child Care and Development Funds § 98.55 Cost allocation. (a) The Lead Agency and subgrantees shall keep on file cost allocation plans or indirect cost agreements, as appropriate, that have...

  8. 45 CFR 1355.57 - Cost allocation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 4 2012-10-01 2012-10-01 false Cost allocation. 1355.57 Section 1355.57 Public... MAINTENANCE PAYMENTS, ADOPTION ASSISTANCE, AND CHILD AND FAMILY SERVICES GENERAL § 1355.57 Cost allocation. (a...) Cost allocation and distribution for the planning, design, development, installation and operation...

  9. 45 CFR 400.13 - Cost allocation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 2 2013-10-01 2012-10-01 true Cost allocation. 400.13 Section 400.13 Public... for Refugee Resettlement Award of Grants to States § 400.13 Cost allocation. (a) A State must allocate... management of the State's refugee program (e.g., development of the State plan, overall program...

  10. 45 CFR 400.13 - Cost allocation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 2 2012-10-01 2012-10-01 false Cost allocation. 400.13 Section 400.13 Public... for Refugee Resettlement Award of Grants to States § 400.13 Cost allocation. (a) A State must allocate... management of the State's refugee program (e.g., development of the State plan, overall program...

  11. Thioether bond formation by SPASM domain radical SAM enzymes: Cα H-atom abstraction in subtilosin A biosynthesis.

    PubMed

    Benjdia, Alhosna; Guillot, Alain; Lefranc, Benjamin; Vaudry, Hubert; Leprince, Jérôme; Berteau, Olivier

    2016-05-01

    AlbA is a radical SAM enzyme catalyzing the formation of three unusual thioether bonds in the antibiotic subtilosin A. We demonstrate here that AlbA catalyzes direct Cα H-atom abstraction and likely contains three essential [4Fe-4S] centers. This leads us to propose novel mechanistic perspectives for thioether bond catalysis by radical SAM enzymes. PMID:27087315

  12. Organic chemistry on surfaces: Direct cyclopropanation by dihalocarbene addition to vinyl terminated self-assembled monolayers (SAMs).

    PubMed

    Adamkiewicz, Malgorzata; O'Hagan, David; Hähner, Georg

    2014-01-01

    C11-Vinyl-terminated self-assembled monolayers (SAMs) on silica surfaces are successfully modified in C-C bond forming reactions with dihalocarbenes to generate SAMs, terminated with dihalo- (fluoro, chloro, bromo) cyclopropane motifs with about 30% surface coverage. PMID:25550756

  13. Organic chemistry on surfaces: Direct cyclopropanation by dihalocarbene addition to vinyl terminated self-assembled monolayers (SAMs)

    PubMed Central

    Adamkiewicz, Malgorzata

    2014-01-01

    Summary C11-Vinyl-terminated self-assembled monolayers (SAMs) on silica surfaces are successfully modified in C–C bond forming reactions with dihalocarbenes to generate SAMs, terminated with dihalo- (fluoro, chloro, bromo) cyclopropane motifs with about 30% surface coverage. PMID:25550756

  14. Analysis of the interactions between host factor Sam68 and viral elements during foot-and-mouth disease virus infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The nuclear protein Src-associated protein of 68 kDa in mitosis (Sam68) is known to bind RNA and be involved in cellular processes triggered in response to environmental stresses, including virus infection. Interestingly, Sam68, is a multi-functional protein implicated in the life cycle of retroviru...

  15. Using Regression Analysis in Departmental Budget Allocations. IR Applications, Volume 24, November 1, 2009

    ERIC Educational Resources Information Center

    Luna, Andrew L.; Brennan, Kelly A.

    2009-01-01

    This study uses a regression model to determine if a significant difference exists between the actual budget allocation that an academic department received and the model's predicted budget allocation for that same department. Budget data from a Southeastern Master's/Comprehensive state university were used as the dependent variable, and the…

  16. Communication patterns and allocation strategies.

    SciTech Connect

    Leung, Vitus Joseph; Mache, Jens Wolfgang; Bunde, David P.

    2004-01-01

    Motivated by observations about job runtimes on the CPlant system, we use a trace-driven microsimulator to begin characterizing the performance of different classes of allocation algorithms on jobs with different communication patterns in space-shared parallel systems with mesh topology. We show that relative performance varies considerably with communication pattern. The Paging strategy using the Hilbert space-filling curve and the Best Fit heuristic performed best across several communication patterns.

  17. Mesospheric effects of solar ultraviolet variations - Further analysis of SME IR ozone and Nimbus 7 SAMS temperature data

    NASA Technical Reports Server (NTRS)

    Hood, L. L.; Huang, Z.; Bougher, S. W.

    1991-01-01

    In order to improve the constraints on models of the mesospheric response to solar UV variations, an analysis is conducted of the Solar Mesosphere Explorer (SME) IR ozone data and Nimbus 7 stratosphere and mesosphere sounder (SAMS) temperature data. Maximum low-altitude ozone and temperature-response amplitudes occur at about the same altitude, where a strong coupling between photochemical and thermal components of the mesospheric response is suggested by the simultaneous positive temperature and negative ozone response maxima. Increased Lyman-alpha dissociation of water vapor and temperature feedback are theorized to account for the negative ozone response. HO(x) chemical heating can increase as ozone destruction increases, and can therefore account for the positive temperature response.

  18. Solving the optimal attention allocation problem in manual control

    NASA Technical Reports Server (NTRS)

    Kleinman, D. L.

    1976-01-01

    Within the context of the optimal control model of human response, analytic expressions for the gradients of closed-loop performance metrics with respect to human operator attention allocation are derived. These derivatives serve as the basis for a gradient algorithm that determines the optimal attention that a human should allocate among several display indicators in a steady-state manual control task. Application of the human modeling techniques are made to study the hover control task for a CH-46 VTOL flight tested by NASA.

  19. Optimal Allocation of Node Capacity in Cascade-Robustness Networks

    PubMed Central

    Chen, Zhen; Zhang, Jun; Du, Wen-Bo; Lordan, Oriol; Tang, Jiangjun

    2015-01-01

    The robustness of large scale critical infrastructures, which can be modeled as complex networks, is of great significance. One of the most important means to enhance robustness is to optimize the allocation of resources. Traditional allocation of resources is mainly based on the topology information, which is neither realistic nor systematic. In this paper, we try to build a framework for searching for the most favorable pattern of node capacity allocation to reduce the vulnerability to cascading failures at a low cost. A nonlinear and multi-objective optimization model is proposed and tackled using a particle swarm optimization algorithm (PSO). It is found that the network becomes more robust and economical when less capacity is left on the heavily loaded nodes and the optimized network performs better resisting noise. Our work is helpful in designing a robust economical network. PMID:26496705

  20. Using hierarchical P-median problem for public school allocation

    NASA Astrophysics Data System (ADS)

    Nasir, Noryanti; Shariff, S. Sarifah Radiah

    2014-09-01

    Student's orientation from primary to the secondary schools is a vital process and need to be considered as yearly problem by The District Education Office of Ministry of Education Malaysia. The allocation of students to the right schools becomes complicated due to several constraints like capacity of seats in secondary schools, widespread demand areas as well as preferences by the parents. Considering all the constraints, this study proposes the application of location model to allocate students the right school. The allocation of student from primary to secondary school is based on total number of students, the availability of seats from primary and at the secondary schools, and distance from student's home to the nearest schools, both primary and secondary schools. The problem is modelled as hierarchical P-median problem as there are two hierarchical levels in this orientation. An alternative Genetic Algorithm (GA) based heuristic is applied to solve the problem and results are compared with Excel Solver.

  1. Optimal Allocation of Node Capacity in Cascade-Robustness Networks.

    PubMed

    Chen, Zhen; Zhang, Jun; Du, Wen-Bo; Lordan, Oriol; Tang, Jiangjun

    2015-01-01

    The robustness of large scale critical infrastructures, which can be modeled as complex networks, is of great significance. One of the most important means to enhance robustness is to optimize the allocation of resources. Traditional allocation of resources is mainly based on the topology information, which is neither realistic nor systematic. In this paper, we try to build a framework for searching for the most favorable pattern of node capacity allocation to reduce the vulnerability to cascading failures at a low cost. A nonlinear and multi-objective optimization model is proposed and tackled using a particle swarm optimization algorithm (PSO). It is found that the network becomes more robust and economical when less capacity is left on the heavily loaded nodes and the optimized network performs better resisting noise. Our work is helpful in designing a robust economical network. PMID:26496705

  2. Innovative Approach for Developing Spacecraft Interior Acoustic Requirement Allocation

    NASA Technical Reports Server (NTRS)

    Chu, S. Reynold; Dandaroy, Indranil; Allen, Christopher S.

    2016-01-01

    The Orion Multi-Purpose Crew Vehicle (MPCV) is an American spacecraft for carrying four astronauts during deep space missions. This paper describes an innovative application of Power Injection Method (PIM) for allocating Orion cabin continuous noise Sound Pressure Level (SPL) limits to the sound power level (PWL) limits of major noise sources in the Environmental Control and Life Support System (ECLSS) during all mission phases. PIM is simulated using both Statistical Energy Analysis (SEA) and Hybrid Statistical Energy Analysis-Finite Element (SEA-FE) models of the Orion MPCV to obtain the transfer matrix from the PWL of the noise sources to the acoustic energies of the receivers, i.e., the cavities associated with the cabin habitable volume. The goal of the allocation strategy is to control the total energy of cabin habitable volume for maintaining the required SPL limits. Simulations are used to demonstrate that applying the allocated PWLs to the noise sources in the models indeed reproduces the SPL limits in the habitable volume. The effects of Noise Control Treatment (NCT) on allocated noise source PWLs are investigated. The measurement of source PWLs of involved fan and pump development units are also discussed as it is related to some case-specific details of the allocation strategy discussed here.

  3. Effects of adaptive task allocation on monitoring of automated systems

    NASA Technical Reports Server (NTRS)

    Parasuraman, R.; Mouloua, M.; Molloy, R.

    1996-01-01

    The effects of adaptive task allocation on monitoring for automation failure during multitask flight simulation were examined. Participants monitored an automated engine status task while simultaneously performing tracking and fuel management tasks over three 30-min sessions. Two methods of adaptive task allocation, both involving temporary return of the automated engine status task to the human operator ("human control"), were examined as a possible countermeasure to monitoring inefficiency. For the model-based adaptive group, the engine status task was allocated to all participants in the middle of the second session for 10 min, following which it was again returned to automation control. The same occurred for the performance-based adaptive group, but only if an individual participant's monitoring performance up to that point did not meet a specified criterion. For the nonadaptive control groups, the engine status task remained automated throughout the experiment. All groups had low probabilities of detection of automation failures for the first 40 min spent with automation. However, following the 10-min intervening period of human control, both adaptive groups detected significantly more automation failures during the subsequent blocks under automation control. The results show that adaptive task allocation can enhance monitoring of automated systems. Both model-based and performance-based allocation improved monitoring of automation. Implications for the design of automated systems are discussed.

  4. Mechanistic Diversity of Radical S-Adenosylmethionine (SAM)-dependent Methylation*

    PubMed Central

    Bauerle, Matthew R.; Schwalm, Erica L.; Booker, Squire J.

    2015-01-01

    Radical S-adenosylmethionine (SAM) enzymes use the oxidizing power of a 5′-deoxyadenosyl 5′-radical to initiate an amazing array of transformations, usually through the abstraction of a target substrate hydrogen atom. A common reaction of radical SAM (RS) enzymes is the methylation of unactivated carbon or phosphorous atoms found in numerous primary and secondary metabolites, as well as in proteins, sugars, lipids, and RNA. However, neither the chemical mechanisms by which these unactivated atoms obtain methyl groups nor the actual methyl donors are conserved. In fact, RS methylases have been grouped into three classes based on protein architecture, cofactor requirement, and predicted mechanism of catalysis. Class A methylases use two cysteine residues to methylate sp2-hybridized carbon centers. Class B methylases require a cobalamin cofactor to methylate both sp2-hybridized and sp3-hybridized carbon centers as well as phosphinate phosphorous atoms. Class C methylases share significant sequence homology with the RS enzyme, HemN, and may bind two SAM molecules simultaneously to methylate sp2-hybridized carbon centers. Lastly, we describe a new class of recently discovered RS methylases. These Class D methylases, unlike Class A, B, and C enzymes, which use SAM as the source of the donated methyl carbon, are proposed to methylate sp2-hybridized carbon centers using methylenetetrahydrofolate as the source of the appended methyl carbon. PMID:25477520

  5. Mechanistic diversity of radical S-adenosylmethionine (SAM)-dependent methylation.

    PubMed

    Bauerle, Matthew R; Schwalm, Erica L; Booker, Squire J

    2015-02-13

    Radical S-adenosylmethionine (SAM) enzymes use the oxidizing power of a 5'-deoxyadenosyl 5'-radical to initiate an amazing array of transformations, usually through the abstraction of a target substrate hydrogen atom. A common reaction of radical SAM (RS) enzymes is the methylation of unactivated carbon or phosphorous atoms found in numerous primary and secondary metabolites, as well as in proteins, sugars, lipids, and RNA. However, neither the chemical mechanisms by which these unactivated atoms obtain methyl groups nor the actual methyl donors are conserved. In fact, RS methylases have been grouped into three classes based on protein architecture, cofactor requirement, and predicted mechanism of catalysis. Class A methylases use two cysteine residues to methylate sp(2)-hybridized carbon centers. Class B methylases require a cobalamin cofactor to methylate both sp(2)-hybridized and sp(3)-hybridized carbon centers as well as phosphinate phosphorous atoms. Class C methylases share significant sequence homology with the RS enzyme, HemN, and may bind two SAM molecules simultaneously to methylate sp(2)-hybridized carbon centers. Lastly, we describe a new class of recently discovered RS methylases. These Class D methylases, unlike Class A, B, and C enzymes, which use SAM as the source of the donated methyl carbon, are proposed to methylate sp(2)-hybridized carbon centers using methylenetetrahydrofolate as the source of the appended methyl carbon. PMID:25477520

  6. A Normalizing Approach to Cognitive Therapy for Intrusive Obsessional and Psychotic Phenomena: The Case of Sam

    ERIC Educational Resources Information Center

    Morrison, Anthony P.

    2005-01-01

    The case of Sam is conceptualized using a normalizing cognitive approach, which assumes that the cultural acceptability of his appraisals distinguishes them as psychotic. The treatment approach that is based upon such a case formulation involves the evaluation of such distressing appraisals and the generation of alternative explanations.…

  7. Treating Obsessive-Compulsive Disorder and Schizophrenia: The Case of Sam

    ERIC Educational Resources Information Center

    Peasley-Miklus, Catherine; Massie, Elise; Baslett, Gaston; Carmin, Cheryl

    2005-01-01

    This article describes the case of Sam, a 22-year-old male with obsessive-compulsive disorder (OCD) and schizophrenia. The patient's background, the development and characteristics of his OCD and schizophrenia, and the history of what became a rather complicated treatment are described. In addition, four problem areas of therapy are identified.

  8. 19. (4"X5" image enlarged from 2 1/4" negative) Sam Fowler, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. (4"X5" image enlarged from 2 1/4" negative) Sam Fowler, Photographer, February 1998 VIEW OF GEORGIA DOT BRIDGE NO. 051-00025D-01986N (JAMES P. HOULIHAN BRIDGE). NAVIGATIONAL LIGHT LOCATED ON TOP OF FENDER - Georgia DOT Bridge No. 051-00025D-01986N, US 17 & State Route 25 Spanning Savannah River, Port Wentworth, Chatham County, GA

  9. 75 FR 4579 - Certificate of Alternative Compliance for the Tugboat MR SAM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-28

    ... SECURITY Coast Guard Certificate of Alternative Compliance for the Tugboat MR SAM AGENCY: Coast Guard, DHS. ACTION: Notice. SUMMARY: The Coast Guard announces that a Certificate of Alternative Compliance was... of Alternative Compliance was issued on December 11, 2009. ADDRESSES: The docket for this notice...

  10. A novel function for Sam68: Enhancement of HIV-1 RNA 3′ end processing

    PubMed Central

    MCLAREN, MEREDITH; ASAI, KENGO; COCHRANE, ALAN

    2004-01-01

    Both cis elements and host cell proteins can significantly affect HIV-1 RNA processing and viral gene expression. Previously, we determined that the exon splicing silencer (ESS3) within the terminal exon of HIV-1 not only reduces use of the adjacent 3′ splice site but also prevents Rev-induced export of the unspliced viral RNA to the cytoplasm. In this report, we demonstrate that loss of unspliced viral RNA export is correlated with the inhibition of 3′ end processing by the ESS3. Furthermore, we find that the host factor Sam68, a stimulator of HIV-1 protein expression, is able to reverse the block to viral RNA export mediated by the ESS3. The reversal is associated with a stimulation of 3′ end processing of the unspliced viral RNA. Our findings identify a novel activity for the ESS3 and Sam68 in regulating HIV-1 RNA polyadenylation. Furthermore, the observations provide an explanation for how Sam68, an exclusively nuclear protein, modulates cytoplasmic utilization of the affected RNAs. Our finding that Sam68 is also able to enhance 3′ end processing of a heterologous RNA raises the possibility that it may play a similar role in regulating host gene expression. PMID:15208447

  11. Making Time for Instructional Leadership. Volume 1: The Evolution of the SAM Process

    ERIC Educational Resources Information Center

    Goldring, Ellen; Grissom, Jason A.; Neumerski, Christine M.; Murphy, Joseph; Blissett, Richard; Porter, Andy

    2015-01-01

    This three-volume report describes the "SAM (School Administration Manager) process," an approach that about 700 schools around the nation are using to direct more of principals' time and effort to improve teaching and learning in classrooms. Research has shown that a principal's instructional leadership is second only to teaching among…

  12. 14. (4"X5" image enlarged from 2 1/4" negative) Sam Fowler, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. (4"X5" image enlarged from 2 1/4" negative) Sam Fowler, Photographer, February 1998 VIEW OF GEORGIA DOT BRIDGE NO. 051-00025D-01986N (JAMES P. HOULIHAN BRIDGE) TURN-SPAN AND LOCKING MECHANISM - Georgia DOT Bridge No. 051-00025D-01986N, US 17 & State Route 25 Spanning Savannah River, Port Wentworth, Chatham County, GA

  13. 17. (4"X5" image enlarged from 2 1/4" negative) Sam Fowler, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. (4"X5" image enlarged from 2 1/4" negative) Sam Fowler, Photographer, February 1998 VIEW OF GEORGIA DOT BRIDGE NO. 051-00025D-01986N (JAMES P. HOULIHAN BRIDGE) APPROACH SPAN FENDER - Georgia DOT Bridge No. 051-00025D-01986N, US 17 & State Route 25 Spanning Savannah River, Port Wentworth, Chatham County, GA

  14. 12. (4'X5' image enlarged from 2 1/4' negative) Sam Fowler, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. (4'X5' image enlarged from 2 1/4' negative) Sam Fowler, Photographer, February 1998 VIEW OF GEORGIA DOT BRIDGE NO. 051-00025D-01986N (JAMES P. HOULIHAN BRIDGE) SOUTH SIDE ELEVATION. - Georgia DOT Bridge No. 051-00025D-01986N, US 17 & State Route 25 Spanning Savannah River, Port Wentworth, Chatham County, GA

  15. 15. (4"X5" image enlarged from 2 1/4" negative) Sam Fowler, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. (4"X5" image enlarged from 2 1/4" negative) Sam Fowler, Photographer, February 1998 VIEW OF GEORGIA DOT BRIDGE NO. 051-00025D-01986N (JAMES P. HOULIHAN BRIDGE) PIVOT PIER - Georgia DOT Bridge No. 051-00025D-01986N, US 17 & State Route 25 Spanning Savannah River, Port Wentworth, Chatham County, GA

  16. 16. (4'X5' image enlarged from 2 1/4' negative) Sam Fowler, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. (4'X5' image enlarged from 2 1/4' negative) Sam Fowler, Photographer, February 1998 VIEW OF GEORGIA DOT BRIDGE NO. 051-00025D-01986N (JAMES P. HOULIHAN BRIDGE). DETAIL OF TURN-SPAN MECHANISM. - Georgia DOT Bridge No. 051-00025D-01986N, US 17 & State Route 25 Spanning Savannah River, Port Wentworth, Chatham County, GA

  17. 13. (4'X5' image enlarged from 2 1/4' negative) Sam Fowler, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. (4'X5' image enlarged from 2 1/4' negative) Sam Fowler, Photographer, February 1998 VIEW OF GEORGIA DOT BRIDGE NO. 051-00025D-01986N (JAMES P. HOULIHAN BRIDGE) NORTH SIDE ELEVATION. - Georgia DOT Bridge No. 051-00025D-01986N, US 17 & State Route 25 Spanning Savannah River, Port Wentworth, Chatham County, GA

  18. SAM-based Cell Transfer to Photopatterned Hydrogels for Microengineering Vascular-Like Structures

    PubMed Central

    Sadr, Nasser; Zhu, Mojun; Osaki, Tatsuya; Kakegawa, Takahiro; Yang, Yunzhi; Moretti, Matteo; Fukuda, Junji; Khademhosseini, Ali

    2011-01-01

    A major challenge in tissue engineering is to reproduce the native 3D microvascular architecture fundamental for in vivo functions. Current approaches still lack a network of perfusable vessels with native 3D structural organization. Here we present a new method combining self-assembled monolayer (SAM)-based cell transfer and gelatin methacrylate hydrogel photopatterning techniques for microengineering vascular structures. Human umbilical vein cell (HUVEC) transfer from oligopeptide SAM-coated surfaces to the hydrogel revealed two SAM desorption mechanisms: photoinduced and electrochemically triggered. The former, occurs concomitantly to hydrogel photocrosslinking, and resulted in efficient (>97%) monolayer transfer. The latter, prompted by additional potential application, preserved cell morphology and maintained high transfer efficiency of VE-cadherin positive monolayers over longer culture periods. This approach was also applied to transfer HUVECs to 3D geometrically defined vascular-like structures in hydrogels, which were then maintained in perfusion culture for 15 days. As a step toward more complex constructs, a cell-laden hydrogel layer was photopatterned around the endothelialized channel to mimic the vascular smooth muscle structure of distal arterioles. This study shows that the coupling of the SAM-based cell transfer and hydrogel photocrosslinking could potentially open up new avenues in engineering more complex, vascularized tissue constructs for regenerative medicine and tissue engineering applications. PMID:21802723

  19. The transcription factor FBI-1 inhibits SAM68-mediated BCL-X alternative splicing and apoptosis.

    PubMed

    Bielli, Pamela; Busà, Roberta; Di Stasi, Savino M; Munoz, Manuel J; Botti, Flavia; Kornblihtt, Alberto R; Sette, Claudio

    2014-04-01

    Alternative splicing (AS) is tightly coupled to transcription for the majority of human genes. However, how these two processes are linked is not well understood. Here, we unveil a direct role for the transcription factor FBI-1 in the regulation of AS. FBI-1 interacts with the splicing factor SAM68 and reduces its binding to BCL-X mRNA. This, in turn, results in the selection of the proximal 5' splice site in BCL-X exon 2, thereby favoring the anti-apoptotic BCL-XL variant and counteracting SAM68-mediated apoptosis. Conversely, depletion of FBI-1, or expression of a SAM68 mutant lacking the FBI-1 binding region, restores the ability of SAM68 to induce BCL-XS splicing and apoptosis. FBI-1's role in splicing requires the activity of histone deacetylases, whose pharmacological inhibition recapitulates the effects of FBI-1 knockdown. Our study reveals an unexpected function for FBI-1 in splicing modulation with a direct impact on cell survival. PMID:24514149

  20. SamACO: variable sampling ant colony optimization algorithm for continuous optimization.

    PubMed

    Hu, Xiao-Min; Zhang, Jun; Chung, Henry Shu-Hung; Li, Yun; Liu, Ou

    2010-12-01

    An ant colony optimization (ACO) algorithm offers algorithmic techniques for optimization by simulating the foraging behavior of a group of ants to perform incremental solution constructions and to realize a pheromone laying-and-following mechanism. Although ACO is first designed for solving discrete (combinatorial) optimization problems, the ACO procedure is also applicable to continuous optimization. This paper presents a new way of extending ACO to solving continuous optimization problems by focusing on continuous variable sampling as a key to transforming ACO from discrete optimization to continuous optimization. The proposed SamACO algorithm consists of three major steps, i.e., the generation of candidate variable values for selection, the ants' solution construction, and the pheromone update process. The distinct characteristics of SamACO are the cooperation of a novel sampling method for discretizing the continuous search space and an efficient incremental solution construction method based on the sampled values. The performance of SamACO is tested using continuous numerical functions with unimodal and multimodal features. Compared with some state-of-the-art algorithms, including traditional ant-based algorithms and representative computational intelligence algorithms for continuous optimization, the performance of SamACO is seen competitive and promising. PMID:20371409