Science.gov

Sample records for modeling support contract

  1. Physics modeling support contract: Final report

    SciTech Connect

    Not Available

    1987-09-30

    This document is the final report for the Physics Modeling Support contract between TRW, Inc. and the Lawrence Livermore National Laboratory for fiscal year 1987. It consists of following projects: TIBER physics modeling and systems code development; advanced blanket modeling task; time dependent modeling; and free electron maser for TIBER II.

  2. Analysis of the 918th Contracting Battalion and 410th Contracting Support Brigade Utilizing the Contract Management Maturity Model

    DTIC Science & Technology

    2015-12-01

    Approved for public release; distribution is unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) The purpose of this research ...CONTRACTING BATTALION AND 410TH CONTRACTING SUPPORT BRIGADE UTILIZING THE CONTRACT MANAGEMENT MATURITY MODEL ABSTRACT The purpose of this research is...2 C. RESEARCH QUESTIONS

  3. Analysis of the 918th Contracting Battalion and 410th Contracting Support Brigade Utilizing the Contract Management Maturity Model

    DTIC Science & Technology

    2015-12-01

    Opportunity, Threat ( SWOT ) analysis is an example of an assessment that does just that. Regardless of which type of organizational assessment is used, the...Monterey, CA 93943. Analysis of the 918th Contracting Battalion and 410th Contracting Support Brigade Utilizing the Contract Management Maturity...Freedom for a total of 24 months. Upon redeployment, Captain Valentine attended the Aviation Captain’s Career Course at Fort Rucker, Alabama. In

  4. Past and ongoing shifts in Joshua tree distribution support future modeled range contraction

    Treesearch

    Kenneth L. Cole; Kirsten Ironside; Jon Eischeid; Gregg Garfin; Phillip B. Duffy; Chris Toney

    2011-01-01

    The future distribution of the Joshua tree (Yucca brevifolia) is projected by combining a geostatistical analysis of 20th-century climates over its current range, future modeled climates, and paleoecological data showing its response to a past similar climate change. As climate rapidly warmed ~11 700 years ago, the range of Joshua tree contracted, leaving only the...

  5. An optimization modeling approach to awarding large fire support wildfire helicopter contracts from the US Forest Service

    Treesearch

    Stephanie A. Snyder; Keith D. Stockmann; Gaylord E. Morris

    2012-01-01

    The US Forest Service used contracted helicopter services as part of its wildfire suppression strategy. An optimization decision-modeling system was developed to assist in the contract selection process. Three contract award selection criteria were considered: cost per pound of delivered water, total contract cost, and quality ratings of the aircraft and vendors....

  6. Past and ongoing shifts in Joshua tree distribution support future modeled range contraction

    USGS Publications Warehouse

    Cole, Kenneth L.; Ironside, Kirsten; Eischeid, Jon K.; Garfin, Gregg; Duffy, Phil; Toney, Chris

    2011-01-01

    The future distribution of the Joshua tree (Yucca brevifolia) is projected by combining a geostatistical analysis of 20th-century climates over its current range, future modeled climates, and paleoecological data showing its response to a past similar climate change. As climate rapidly warmed ;11 700 years ago, the range of Joshua tree contracted, leaving only the populations near what had been its northernmost limit. Its ability to spread northward into new suitable habitats after this time may have been inhibited by the somewhat earlier extinction of megafaunal dispersers, especially the Shasta ground sloth. We applied a model of climate suitability for Joshua tree, developed from its 20th-century range and climates, to future climates modeled through a set of six individual general circulation models (GCM) and one suite of 22 models for the late 21st century. All distribution data, observed climate data, and future GCM results were scaled to spatial grids of ;1 km and ;4 km in order to facilitate application within this topographically complex region. All of the models project the future elimination of Joshua tree throughout most of the southern portions of its current range. Although estimates of future monthly precipitation differ between the models, these changes are outweighed by large increases in temperature common to all the models. Only a few populations within the current range are predicted to be sustainable. Several models project significant potential future expansion into new areas beyond the current range, but the species' Historical and current rates of dispersal would seem to prevent natural expansion into these new areas. Several areas are predicted to be potential sites for relocation/ assisted migration. This project demonstrates how information from paleoecology and modern ecology can be integrated in order to understand ongoing processes and future distributions.

  7. Improving Army Operational Contract Support

    DTIC Science & Technology

    2013-04-01

    Management in Expeditionary Operations . And, this research reviews the DOD Contingency Contracting Handbook. The research recommends the Army improve...Program Management in Expeditionary Operations and the Department of Defense Office of Inspector General that pertain to recent contingency...Contracting and Contract Management in Expeditionary Operations . And, this research reviews the DOD Contingency Contracting Handbook. The research

  8. Model for Contingency Contracting.

    ERIC Educational Resources Information Center

    Prince George's Community Coll., Largo, MD. Dept. of Human Development.

    The Department of Human Development at Prince George's Community College has developed a contingency contracting model for the department's counseling and student services which presents planning and evaluation as interrelated parts of the same process of self-imposed accountability. The implementation of the model consisted of: (1) planning…

  9. Uterine Contraction Modeling and Simulation

    NASA Technical Reports Server (NTRS)

    Liu, Miao; Belfore, Lee A.; Shen, Yuzhong; Scerbo, Mark W.

    2010-01-01

    Building a training system for medical personnel to properly interpret fetal heart rate tracing requires developing accurate models that can relate various signal patterns to certain pathologies. In addition to modeling the fetal heart rate signal itself, the change of uterine pressure that bears strong relation to fetal heart rate and provides indications of maternal and fetal status should also be considered. In this work, we have developed a group of parametric models to simulate uterine contractions during labor and delivery. Through analysis of real patient records, we propose to model uterine contraction signals by three major components: regular contractions, impulsive noise caused by fetal movements, and low amplitude noise invoked by maternal breathing and measuring apparatus. The regular contractions are modeled by an asymmetric generalized Gaussian function and least squares estimation is used to compute the parameter values of the asymmetric generalized Gaussian function based on uterine contractions of real patients. Regular contractions are detected based on thresholding and derivative analysis of uterine contractions. Impulsive noise caused by fetal movements and low amplitude noise by maternal breathing and measuring apparatus are modeled by rational polynomial functions and Perlin noise, respectively. Experiment results show the synthesized uterine contractions can mimic the real uterine contractions realistically, demonstrating the effectiveness of the proposed algorithm.

  10. Teacher Views on Organizational Support and Psychological Contract Violation

    ERIC Educational Resources Information Center

    Argon, Türkan; Ekinci, Serkan

    2017-01-01

    This study aimed to determine the relationship between secondary school teachers' view regarding Organizational Support and Psychological Contract Violation. The study conducted with relational screening model included 230 secondary school teachers employed in Bolu central district in 2014-2015 academic year. Perceived Organizational Support Scale…

  11. 10 CFR 950.13 - Standby Support Contract: General provisions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Standby Support Contract: General provisions. 950.13 Section 950.13 Energy DEPARTMENT OF ENERGY STANDBY SUPPORT FOR CERTAIN NUCLEAR PLANT DELAYS Standby Support Contract Process § 950.13 Standby Support Contract: General provisions. (a) Purpose. Each Standby...

  12. 10 CFR 950.12 - Standby Support Contract Conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Standby Support Contract Conditions. 950.12 Section 950.12 Energy DEPARTMENT OF ENERGY STANDBY SUPPORT FOR CERTAIN NUCLEAR PLANT DELAYS Standby Support Contract Process § 950.12 Standby Support Contract Conditions. (a) Conditions Precedent. If Program Administrator...

  13. When Disaster Strikes Is Logistics and Contracting Support Ready?

    DTIC Science & Technology

    2011-09-27

    When Disaster Strikes Is Logistics and Contracting Support Ready? 27 September 2011 by Dr. Aruna Apte, Assistant Professor, and CDR (Ret...the Authors Dr. Aruna Apte has successfully completed various research projects, involving application of mathematical models and optimization...She has recently published a monograph on Humanitarian Logistics. Aruna received her PhD in Operations Research from Southern Methodist University

  14. 76 FR 81807 - Operational Contract Support

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-29

    ... designated non-contracting personnel. Contract administration delegation. A CCDR policy or process related to.... forces (especially in non- permissive environments). Personnel co-located with U.S. forces shall be... other legal non-Federal entity that enters into a contract directly with the DoD to furnish...

  15. Dual Support in Contract Workers' Triangular Employment Relationships

    ERIC Educational Resources Information Center

    Buch, Robert; Kuvaas, Bard; Dysvik, Anders

    2010-01-01

    This study investigated the interplay between perceived investment in contract worker development by the "client" organization and contract workers' perceived organizational support from their temporary employment "agency." A study among 2021 contract workers from three temporary employment agencies in Norway showed that the…

  16. Dual Support in Contract Workers' Triangular Employment Relationships

    ERIC Educational Resources Information Center

    Buch, Robert; Kuvaas, Bard; Dysvik, Anders

    2010-01-01

    This study investigated the interplay between perceived investment in contract worker development by the "client" organization and contract workers' perceived organizational support from their temporary employment "agency." A study among 2021 contract workers from three temporary employment agencies in Norway showed that the…

  17. Exchange relationships: examining psychological contracts and perceived organizational support.

    PubMed

    Coyle-Shapiro, Jacqueline A-M; Conway, Neil

    2005-07-01

    The authors surveyed 347 public sector employees on 4 measurement occasions to investigate the conceptual distinctiveness of the psychological contract and perceived organizational support (POS) and how they are associated over time. Results support the distinctiveness of the 2 concepts. In terms of their interrelationships over time, by drawing on psychological contract theory the authors found little support for a reciprocal relationship between POS and psychological contract fulfillment. Under an alternative set of hypotheses, by drawing on organizational support theory and by separating psychological contract fulfillment into its 2 components (perceived employer obligations and inducements), the authors found that perceived employer inducements were positively related to POS, which, in turn, was negatively related to perceived employer obligations. The results suggest that POS and the components of psychological contract fulfillment are more important in predicting organizational citizenship behavior than psychological contract fulfillment.

  18. PHYSICAL MODELING OF CONTRACTED FLOW.

    USGS Publications Warehouse

    Lee, Jonathan K.

    1987-01-01

    Experiments on steady flow over uniform grass roughness through centered single-opening contractions were conducted in the Flood Plain Simulation Facility at the U. S. Geological Survey's Gulf Coast Hydroscience Center near Bay St. Louis, Miss. The experimental series was designed to provide data for calibrating and verifying two-dimensional, vertically averaged surface-water flow models used to simulate flow through openings in highway embankments across inundated flood plains. Water-surface elevations, point velocities, and vertical velocity profiles were obtained at selected locations for design discharges ranging from 50 to 210 cfs. Examples of observed water-surface elevations and velocity magnitudes at basin cross-sections are presented.

  19. Insurance Contract Analysis for Company Decision Support in Acquisition Management

    NASA Astrophysics Data System (ADS)

    Chernovita, H. P.; Manongga, D.; Iriani, A.

    2017-01-01

    One of company activities to retain their business is marketing the products which include in acquisition management to get new customers. Insurance contract analysis using ID3 to produce decision tree and rules to be decision support for the insurance company. The decision tree shows 13 rules that lead to contract termination claim. This could be a guide for the insurance company in acquisition management to prevent contract binding with these contract condition because it has a big chance for the customer to terminate their insurance contract before its expired date. As the result, there are several strong points that could be the determinant of contract termination such as: 1) customer age whether too young or too old, 2) long insurance period (above 10 years), 3) big insurance amount, 4) big amount of premium charges, and 5) payment method.

  20. 10 CFR 950.12 - Standby Support Contract Conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Energy DEPARTMENT OF ENERGY STANDBY SUPPORT FOR CERTAIN NUCLEAR PLANT DELAYS Standby Support Contract... construction, testing and full power operation of the advanced nuclear facility. (9) Provided to the Program... construction of the advanced nuclear facility; (5) Documented coverage of insurance required for the project...

  1. 10 CFR 950.12 - Standby Support Contract Conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Energy DEPARTMENT OF ENERGY STANDBY SUPPORT FOR CERTAIN NUCLEAR PLANT DELAYS Standby Support Contract... construction, testing and full power operation of the advanced nuclear facility. (9) Provided to the Program... construction of the advanced nuclear facility; (5) Documented coverage of insurance required for the project...

  2. 10 CFR 950.12 - Standby Support Contract Conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Energy DEPARTMENT OF ENERGY STANDBY SUPPORT FOR CERTAIN NUCLEAR PLANT DELAYS Standby Support Contract... construction, testing and full power operation of the advanced nuclear facility. (9) Provided to the Program... construction of the advanced nuclear facility; (5) Documented coverage of insurance required for the project...

  3. 10 CFR 950.12 - Standby Support Contract Conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Energy DEPARTMENT OF ENERGY STANDBY SUPPORT FOR CERTAIN NUCLEAR PLANT DELAYS Standby Support Contract... construction, testing and full power operation of the advanced nuclear facility. (9) Provided to the Program... construction of the advanced nuclear facility; (5) Documented coverage of insurance required for the project...

  4. A Motivation Contract Model of Employee Appraisal.

    ERIC Educational Resources Information Center

    Glenn, Robert B.

    The purpose of this paper is to develop a process model for identification and assessment of employee job performance, through motivation contracting. The model integrated various components of expectancy theories of motivation and performance contracting and is based on humanistic assumptions about the nature of people. More specifically, the…

  5. Operational Contract Support: Management and Oversight Improvements Needed in Afghanistan

    DTIC Science & Technology

    2012-03-01

    31The photographs in this report were selected from photographs provided by...identified in the photographs are derived from statements from officials or DOD documentation. has also reported significant construction deficiencies...examined photographs of supplies and services provided to us by the DOD personnel to best illustrate the nature of the contract support issues we

  6. A biomechanical model of wound contraction and scar formation.

    PubMed

    Yang, Le; Witten, Tarynn M; Pidaparti, Ramana M

    2013-09-07

    We propose a biomechanical model for investigating wound contraction mechanism and resulting scarring. Extracellular matrix is modeled as fiber-reinforced anisotropic soft tissue, with its elastic properties dynamically changing with the density and orientation of collagen fibers. Collagen fibers are deposited by fibroblasts infiltrating the wound space, and are dynamically aligned with both migrating fibroblasts and tissue residing tension field. Our new 2D hybrid agent-based model provides a comprehensive platform for examining the mechanobiology in wound contraction and scar formation. Simulation results are consistent with experimental observations and are able to reveal the effects of wound morphology and mechanical environment on contraction patterns. Our model results support the hypothesis that scar formation is the product of collagen fiber synthesis and alignment in the presence of the tensile stress field generated by a wound contraction process. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Warfighter Support: DOD Needs Additional Steps to Fully Integrate Operational Contract Support into Contingency Planning

    DTIC Science & Technology

    2013-02-01

    Planning Report to the Chairman, Subcommittee on Contracting Oversight, Committee on Homeland Security and Governmental Affairs, U.S. Senate...TITLE AND SUBTITLE Warfighter Support: DOD Needs Additional Steps to Fully Integrate Operational Contract Support into Contingency Planning 5a...Support into Contingency Planning Why GAO Did This Study DOD has relied extensively on contractors for operations in Iraq and Afghanistan over the

  8. Flawed Execution: A Case Study on Operational Contract Support

    DTIC Science & Technology

    2016-06-01

    services as a whole have done a poor job of teaching their leaders how to effectively plan for and manage operational contract support, starting...has become a vital necessity. Despite the last decade and a half of armed conflict, the military services as a whole have done a poor job of teaching...several different vendors, thus bolstering the financial health of more than one company and increasing local employment. Coordinated effort leverages

  9. Preliminary Results to Support Evidence of Thermospheric Contraction

    NASA Astrophysics Data System (ADS)

    Saunders, A.; Swinerd, G.; Lewis, H.

    Atmospheric density has an important influence in predicting the positions of satellites in low Earth orbit. For long-term predictions of satellite ephemerides, any density trend in the thermosphere would be a valuable input, not only to satellite operators, but also to studies of the future low Earth orbit environment in terms of space debris. A secular thermospheric density trend has not yet been definitively proven but predictions by Ramesh and Roble [1], along with evidence by Emmert et al. [2], strongly suggest the existence of such a phenomenon. With the ultimate goal of deriving a long-term empirical model of thermospheric cooling and contraction, the primary focus of this paper is to present preliminary results obtained to support the existing evidence for such a thermospheric contraction. There are many ways of determining atmospheric density, but inferring thermospheric density from satellite drag data is a relatively cost-effective way of gathering in-situ measurements. Given an initial satellite orbit, one approach is to use an orbital propagator to predict the satellite's state at some time ahead and then to compare that state with Two-Line Element (TLE) data at the same epoch. The difference between the semi-major axis of the satellite from the initial orbit and that after the orbit propagation is then integrated to obtain an estimate of global average density. This is the approach adopted in our new work, using a bespoke, orbital propagator that includes perturbations due to atmospheric drag, gravitational anomalies, luni-solar gravity effects and solar radiation pressure. The methods used to derive precise estimates of the ballistic coefficient of each satellite for use in the propagator are outlined, as this information is not contained explicitly in the TLE sets. In validation of the orbital propagator used in this study, Saunders et al. [3] ran simulations to predict satellite re-entry dates with satisfactory results. Now, historical satellite

  10. Sample Language of Modified Contract Elements from Existing CBAs, MOUs, or EWAs to Support Turnaround

    ERIC Educational Resources Information Center

    Mass Insight Education (NJ1), 2011

    2011-01-01

    Organized by the key conditions areas for turnaround, "People, Program, Time and Money," this tool offers sample language for each contract element to serve as a model for modifications from a traditional CBA that may support a district's turnaround efforts. Sample language is offered from existing provisions in district-wide collective bargaining…

  11. Economic contract theory tests models of mutualism.

    PubMed

    Weyl, E Glen; Frederickson, Megan E; Yu, Douglas W; Pierce, Naomi E

    2010-09-07

    Although mutualisms are common in all ecological communities and have played key roles in the diversification of life, our current understanding of the evolution of cooperation applies mostly to social behavior within a species. A central question is whether mutualisms persist because hosts have evolved costly punishment of cheaters. Here, we use the economic theory of employment contracts to formulate and distinguish between two mechanisms that have been proposed to prevent cheating in host-symbiont mutualisms, partner fidelity feedback (PFF) and host sanctions (HS). Under PFF, positive feedback between host fitness and symbiont fitness is sufficient to prevent cheating; in contrast, HS posits the necessity of costly punishment to maintain mutualism. A coevolutionary model of mutualism finds that HS are unlikely to evolve de novo, and published data on legume-rhizobia and yucca-moth mutualisms are consistent with PFF and not with HS. Thus, in systems considered to be textbook cases of HS, we find poor support for the theory that hosts have evolved to punish cheating symbionts; instead, we show that even horizontally transmitted mutualisms can be stabilized via PFF. PFF theory may place previously underappreciated constraints on the evolution of mutualism and explain why punishment is far from ubiquitous in nature.

  12. Economic contract theory tests models of mutualism

    PubMed Central

    Weyl, E. Glen; Frederickson, Megan E.; Yu, Douglas W.; Pierce, Naomi E.

    2010-01-01

    Although mutualisms are common in all ecological communities and have played key roles in the diversification of life, our current understanding of the evolution of cooperation applies mostly to social behavior within a species. A central question is whether mutualisms persist because hosts have evolved costly punishment of cheaters. Here, we use the economic theory of employment contracts to formulate and distinguish between two mechanisms that have been proposed to prevent cheating in host–symbiont mutualisms, partner fidelity feedback (PFF) and host sanctions (HS). Under PFF, positive feedback between host fitness and symbiont fitness is sufficient to prevent cheating; in contrast, HS posits the necessity of costly punishment to maintain mutualism. A coevolutionary model of mutualism finds that HS are unlikely to evolve de novo, and published data on legume–rhizobia and yucca–moth mutualisms are consistent with PFF and not with HS. Thus, in systems considered to be textbook cases of HS, we find poor support for the theory that hosts have evolved to punish cheating symbionts; instead, we show that even horizontally transmitted mutualisms can be stabilized via PFF. PFF theory may place previously underappreciated constraints on the evolution of mutualism and explain why punishment is far from ubiquitous in nature. PMID:20733067

  13. An Exposition of Fischer's Model of Overlapping Contracts.

    ERIC Educational Resources Information Center

    Fields, T. Windsor; Hart, William R.

    1992-01-01

    Suggests how the classic model of overlapping contracts can be incorporated into the contract wage model of aggregate supply. Illustrates dynamics of macroeconomic adjustment following a shock to aggregate demand. Concludes that overlapping contracts do not prolong the adjustment process; rather, the longest remaining contract determines the time…

  14. Models of muscle contraction and energetics

    PubMed Central

    Lai, Nicola; Gladden, L. Bruce; Carlier, Pierre G.; Cabrera, Marco E.

    2013-01-01

    How does skeletal muscle manage to regulate the pathways of ATP synthesis during large-scale changes in work rate while maintaining metabolic homeostasis remains unknown. The classic model of metabolic regulation during muscle contraction states that accelerating ATP utilization leads to increasing concentrations of ADP and Pi, which serve as substrates for oxidative phosphorylation and thus accelerate ATP synthesis. An alternative model states that both the ATP demand and ATP supply pathways are simultaneously activated. Here, we review experimental and computational models of muscle contraction and energetics at various organizational levels and compare them with respect to their pros and cons in facilitating understanding of the regulation of energy metabolism during exercise in the intact organism. PMID:24421861

  15. 7 CFR 1718.104 - Availability of model loan contract.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 11 2011-01-01 2011-01-01 false Availability of model loan contract. 1718.104 Section 1718.104 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES SERVICE... Borrowers § 1718.104 Availability of model loan contract. Single copies of the model loan contract (RUS...

  16. Future Models for Federally Funded Research and Development Center Contracts

    DTIC Science & Technology

    2016-10-20

    Future Models for Federally Funded Research and Development Center Contracts Approved by the DBB 20 October 2016 Presentation on: Task Group...Development Center (FFRDC) contracts . Specifically, the DBB should;  Review existing governance models, compare management activities to those of the...Center (FFRDC) contracts . Specifically, the DBB should; − Review existing governance models, compare management activities to those of the private

  17. Defense Health Care: Acquisition Process for TRICARE’s Third Generation of Managed Care Support Contracts

    DTIC Science & Technology

    2014-03-01

    Selection Team Roles and Responsibilities for TRICARE’s Contract Award Process 11 Figure 3: Timeline of Bid Protest Events for TRICARE’s North Region...14-195 TRICARE Managed Care Support Contracts Figure 2: Source Selection Team Roles and Responsibilities for TRICARE’s Contract Award Process

  18. When Disaster Strikes: Is Logistics and Contracting Support Ready?

    DTIC Science & Technology

    2011-04-30

    Candidate School in Newport, RI, in November 1979, and graduated from Navy Supply Corps School in May 1980. Dussault has served in USS Point Loma (AGDS-2...Communications Station, Nea Makri, Greece; Defense Contract Administration Services Region (DCASR), Los Angeles ; a negotiator and contracting officer at Naval

  19. An Analysis of Current Operational Contract Support Planning Doctrine

    DTIC Science & Technology

    2015-09-01

    planning activities and common vocabulary linking inorganic acquisition and non-acquisition entities.. Also, that future contingency contracting... vocabulary linking inorganic acquisition and non-acquisition entities.. Also, that future contingency contracting planning guidance developed is...increase language and cultural capabilities and capacities. Markedly improve the ability to integrate with other U.S. agencies and other partners

  20. Q-GERT Model of the Contracting Cycle.

    DTIC Science & Technology

    1983-09-01

    the model accurately simulates what its designed to imitate. This model was designed to simulate the contracting cycle time of the Flight Dynamics...buying personnel provided estimates of a range of time to complete each task. The result was that the model successfully imitated the contracting cycle... time from receipt of the purchase request to the contract award. A manager can use the model to test the effect of changes in resources or procedures

  1. Office of Inspector General report on audit of controls over the ADP support services contract

    SciTech Connect

    1997-08-15

    In March 1995, the Department awarded a cost-plus-award-fee contract to DynCorp valued at approximately $246 million over 5 years for ADP support services at Headquarters. The performance period for the contract was a 3-year base period with two 1-year options. The contract statement of work identified 24 information management functional areas that required technical support services, including Automated Office Systems Support and Local Area Network support. The purpose of the audit was to evaluate the cost-plus-award-fee contract for ADP support services at Headquarters. The objective was to determine whether the Department`s program offices at Headquarters were managing their ADP support services contract costs.

  2. Incomplete Contract Files for Southwest Asia Task Orders on the Warfighter Field Operations Customer Support Contract

    DTIC Science & Technology

    2011-06-01

    Multipurpose Wheeled Vehicle ITAM Iraq Training Advisory Mission MRAP Mine Resistant Ambush Protected PARC Principal Assistant Responsible for...million of training services placed on task order 022; and • Iraq Training and Advisory Mission ( ITAM ) training effort, valued at approximately $66.9...MRAP expedient armor program training effort. ITAM Training Effort PEO STRI contracting personnel awarded the ITAM training effort on the

  3. 48 CFR 222.402-70 - Installation support contracts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... service calls or orders for construction, alteration, renovation, painting, or repairs to buildings or... clauses and minimum wage and fringe benefit requirements to all contract service calls or orders for such..., building structural repair, paving repairs, etc.) are subject to the Construction Wage Rate Requirements...

  4. Contractions

    MedlinePlus

    ... feel tightening of your uterus muscles at irregular intervals or a squeezing sensation in your lower abdomen ... beginning of childbirth. These contractions come at regular intervals, usually move from the back to the lower ...

  5. Volition Support Design Model

    ERIC Educational Resources Information Center

    Kim, ChanMin

    2013-01-01

    The purpose of this paper is to introduce a design model for supporting student volition. First, the construct of volition is explained and the importance of volition is further described in the context of goal attainment. Next, the theoretical basis of the model is described. Last, implications of the model are discussed for the design of…

  6. 48 CFR 5152.245-9000 - Government property for installation support services (fixed-price contracts).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Government property for installation support services (fixed-price contracts). 5152.245-9000 Section 5152.245-9000 Federal Acquisition Regulations System DEPARTMENT OF THE ARMY ACQUISITION REGULATIONS SOLICITATIONS PROVISIONS AND CONTRACT CLAUSES 5152.245-9000...

  7. Contracts for field projects and supporting research on enhanced oil recovery. Progress review No. 89

    SciTech Connect

    1998-04-01

    Summaries are presented for the DOE contracts related to supported research for thermal recovery of petroleum, geoscience technology, and field demonstrations in high-priority reservoir classes. Data included for each project are: title, contract number, principal investigator, research organization, beginning date, expected completion date, amount of award, objectives of the research, and summary of technical progress.

  8. Contingency Contracting Officers: Can They Adequately Support the Force?

    DTIC Science & Technology

    1993-12-01

    Conflicts Air Force Institute of Technology, Wright-Patterson AFB, OH, September 1988. 10. Radin, HAJ Sara R ., Contingency Contracting, A Force Multiplier...public release; distribution is unlimited. 4 Performing Organisation Report Number(s) 5 Monitoring organization Report Number(s) a Mass of Performing...7b Address v.t . and Z"co4e1Monery A 13943-50 Monterey CA 934-5000 Monterey CA 40_0 s Naume of Funding/Sponsoring Sb Office Symbol 9 Procurement

  9. 76 FR 16349 - Notice of Policy Regarding Civil Aircraft Operators Providing Contract Support to Government...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-23

    ... Federal Aviation Administration 14 CFR Chapter 1 Notice of Policy Regarding Civil Aircraft Operators Providing Contract Support to Government Entities (Public Aircraft Operations) AGENCY: Federal Aviation... states the Federal Aviation Administration's (FAA) policy pertaining to civil aircraft operators that...

  10. Support effects studied on model supported catalysts

    SciTech Connect

    Gorte, R.J.

    1993-02-01

    Composition and structure of oxide support materials can change the catalytic behavior of metal and oxide catalysts. Model catalysts are being studied in which the active phase is deposited on flat oxide substrates, with emphasis on metals catalysis for automotive emissions control and acidity in supported oxides. Research is reported in the following areas: particle-size effects, support effects on ZnO and zirconia, support effects on ceria, supported oxides, and low energy ion scattering (no results in the latter).

  11. 7 CFR 1718.104 - Availability of model loan contract.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Availability of model loan contract. 1718.104 Section 1718.104 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE LOAN SECURITY DOCUMENTS FOR ELECTRIC BORROWERS Loan Contracts With Distribution Borrowers § 1718.104 Availability...

  12. 10 CFR 950.13 - Standby Support Contract: General provisions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Section 950.13 Energy DEPARTMENT OF ENERGY STANDBY SUPPORT FOR CERTAIN NUCLEAR PLANT DELAYS Standby... Department shall provide compensation for covered costs incurred by a sponsor for covered events that result in a covered delay of full power operation of an advanced nuclear facility. (b) Covered...

  13. 10 CFR 950.13 - Standby Support Contract: General provisions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Section 950.13 Energy DEPARTMENT OF ENERGY STANDBY SUPPORT FOR CERTAIN NUCLEAR PLANT DELAYS Standby... Department shall provide compensation for covered costs incurred by a sponsor for covered events that result in a covered delay of full power operation of an advanced nuclear facility. (b) Covered...

  14. 10 CFR 950.13 - Standby Support Contract: General provisions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Section 950.13 Energy DEPARTMENT OF ENERGY STANDBY SUPPORT FOR CERTAIN NUCLEAR PLANT DELAYS Standby... Department shall provide compensation for covered costs incurred by a sponsor for covered events that result in a covered delay of full power operation of an advanced nuclear facility. (b) Covered...

  15. 10 CFR 950.13 - Standby Support Contract: General provisions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Section 950.13 Energy DEPARTMENT OF ENERGY STANDBY SUPPORT FOR CERTAIN NUCLEAR PLANT DELAYS Standby... Department shall provide compensation for covered costs incurred by a sponsor for covered events that result in a covered delay of full power operation of an advanced nuclear facility. (b) Covered...

  16. A thermoelastic deformation model of tissue contraction during thermal ablation.

    PubMed

    Park, Chang Sub; Liu, Cong; Hall, Sheldon K; Payne, Stephen J

    2017-06-14

    Thermal ablation is an energy-based ablation technique widely used during minimally invasive cancer treatment. Simulations are used to predict the dead tissue post therapy. However, one difficulty with the simulations is accurately predicting the ablation zone in post-procedural images due to the contraction of tissue as a result of exposure to elevated temperatures. A mathematical model of the thermoelastic deformation for an elastic isotropic material was coupled with a three state thermal denaturation model to determine the contraction of tissue during thermal ablation. A finite difference method was considered to quantify the tissue contraction for a typical temperature distribution during thermal ablation. The simulations show that tissue displacement during thermal ablation was not bound to the tissue heated regions only. Both tissue expansion and contraction were observed at the different stages of the heating process. Tissue contraction of up to 42% was obtained with an applicator temperature of 90 °C. A recovery of around 2% was observed with heating removed as a result of unfolded state proteins returning back to its native state. Poisson's ratio and the applicator temperature have both been shown to affect the tissue displacement significantly. The maximum tissue contraction was found to increase with both increasing Poisson's ratio and temperature. The model presented here will allow predictions of thermal ablation to be corrected for tissue contraction, which is an important effect, during comparison with post-procedural images, thus improving the accuracy of mathematical simulations for treatment planning.

  17. Logistics Support Contracting for the United States Special Operations Command

    DTIC Science & Technology

    2009-05-28

    Development, Test, and Evaluation SOFSA Special Operations Forces Support Activity TAPO Technology Applications Program Office U.S.C United...Violation The Technology Applications Program Office ( TAPO ) did not comply with appropriations laws and regulations when funding task order USZA22-03...C-0056-2237 because TAPO funded $63.6 million of the task order with procurement funds rather than research, development, test, and evaluation (RDT

  18. Base Operation and Support (BOS) Contracts: Their Value to the US Navy

    DTIC Science & Technology

    2007-01-01

    include a wide range of non-core, secondary or administrative support services, operation of public facilities and the like.4 NI, Mahon E., Moore , A...nstiute.org html cr 41.h1m 4𔃾 McMahon E., Moore , A., and Segal G. Private Competition for Public Services: Unfinished Agenda in New York State. August 9...contract for facility services through individual service contracts, or (3) a combination of the two previous examples. According to Fellow, Moore , and

  19. Operational Contract Support: Actions Needed to Enhance the Collection, Integration, and Sharing of Lessons Learned

    DTIC Science & Technology

    2015-03-01

    Additionally, the Army’s Acquisition, Logistics and Technology-Integration Office has fully integrated with the Combined Arms Support Command’s Reverse ...Acquisition, Technology and Logistics ) Memorandum, Charter for the Department of Defense Operational Contract Support Functional Capabilities Integration...Secretary of Defense for Acquisition, Technology and Logistics has overall responsibility for establishing and publishing policies and procedures

  20. The Goddard High Resolution Spectrograph Scientific Support Contract

    NASA Technical Reports Server (NTRS)

    1997-01-01

    In 1988, Computer Sciences Corporation (CSC) was selected as the Goddard High Resolution Spectrograph (GHRS) Scientific Support Contractor (SSC). This was to have been a few months before the launch of NASA's first Great Observatory, the Hubble Space Telescope (HST). As one of five scientific instruments on HST, the GHRS was designed to obtain spectra in the 1050-3300 A ultraviolet wavelength region with a resolving power, lambda/Delta(lambda) , of up to 100,000 and relative photometric accuracy to 1%. It was built by Ball AeroSpace Systems Group under the guidance of the GHRS Investigation Definition Team (IDT), comprised of 16 scientists from the US and Canada. After launch, the IDT was to perform the initial instrument calibration and execute a broad scientific program during a five-year Guaranteed Time Observation (GTO) period. After a year's delay, the launch of HST occurred in April 1990, and CSC participated in the in-orbit calibration and first four years of GTO observations with the IDT. The HST primary mirror suffered from spherical aberration, which reduced the spatial and spectral resolution of Large Science Aperture (LSA) observations and decreased the throughput of the Small Science Aperture (SSA) by a factor of two. Periodic problems with the Side 1 carrousel electronics and anomalies with the low-voltage power supply finally resulted in a suspension of the use of Side 1 less than two years after launch. At the outset, the GHRS SSC task involved work in four areas: 1) to manage and operate the GHRS Data Analysis Facility (DAF); 2) to support the second Servicing Mission Observatory Verification (SMOV) program, as well as perform system engineering analysis of the GHRS as nesessary; 3) to assist the GHRS IDT with their scientific research programs, particularly the GSFC members of the team, and 4) to provide administrative and logistic support for GHRS public information and educational activities.

  1. The relationships between perceived organizational support, affective commitment, psychological contract breach, organizational citizenship behaviour and work engagement.

    PubMed

    Gupta, Vishal; Agarwal, Upasna A; Khatri, Naresh

    2016-11-01

    This study examines the factors that mediate and moderate the relationships of perceived organizational support with work engagement and organization citizenship behaviour. Specifically, affective commitment is posited to mediate and psychological contract breach to moderate the above relationships. Nurses play a critical role in delivering exemplary health care. For nurses to perform at their best, they need to experience high engagement, which can be achieved by providing them necessary organizational support and proper working environment. Data were collected via a self-reported survey instrument. A questionnaire was administered to a random sample of 750 nurses in nine large hospitals in India during 2013-2014. Four hundred and seventy-five nurses (63%) responded to the survey. Hierarchical multiple regression was used for statistical analysis of the moderated-mediation model. Affective commitment was found to mediate the positive relationships between perceived organizational support and work outcomes (work engagement, organizational citizenship behaviour). The perception of unfulfilled expectations (psychological contract breach) was found to moderate the perceived organizational support-work outcome relationships adversely. The results of this study indicate that perceived organizational support exerts its influence on work-related outcomes and highlight the importance of taking organizational context, such as perceptions of psychological contract breach, into consideration when making sense of the influence of perceived organizational support on affective commitment, work engagement and citizenship behaviours of nurses. © 2016 John Wiley & Sons Ltd.

  2. Contracting Janitorial Services. A Training and Production Model.

    ERIC Educational Resources Information Center

    Smith, Christopher A.

    This book provides a model to help facilities for training handicapped persons to teach janitorial work and set up a contracting program for janitorial services. The book is organized in three sections. The first section outlines the training production model, including hints on beginning the venture, separation of training and contracting…

  3. Integrative Systems Models of Cardiac Excitation Contraction Coupling

    PubMed Central

    Greenstein, Joseph L.; Winslow, Raimond L.

    2010-01-01

    Excitation-contraction coupling in the cardiac myocyte is mediated by a number of highly integrated mechanisms of intracellular Ca2+ transport. The complexity and integrative nature of heart cell electrophysiology and Ca2+-cycling has led to an evolution of computational models that have played a crucial role in shaping our understanding of heart function. An important emerging theme in systems biology is that the detailed nature of local signaling events, such as those that occur in the cardiac dyad, have important consequences at higher biological scales. Multi-scale modeling techniques have revealed many mechanistic links between micro-scale events, such as Ca2+ binding to a channel protein, and macro-scale phenomena, such as excitation-contraction coupling gain. Here we review experimentally based multi-scale computational models of excitation-contraction coupling and the insights that have been gained through their application. PMID:21212390

  4. Beyond altruistic and commercial contract motherhood: the professional model.

    PubMed

    Van Zyl, Liezl; Walker, Ruth

    2013-09-01

    It has become common to distinguish between altruistic and commercial contract motherhood (or 'surrogacy'). Altruistic arrangements are based on the 'gift relationship': a woman is motivated by altruism to have a baby for an infertile couple, who are free to reciprocate as they see fit. By contrast, in commercial arrangements both parties are motivated by personal gain to enter a legally enforceable agreement, which stipulates that the contract mother or 'surrogate' is to bear a child for the intending parents in exchange for a fee. She is required to undergo medical examinations and to refrain from behaviour that could harm the foetus. The intending parents are the child's legal parents from the outset. The parties to the contract can, but are not expected to, maintain contact after the transaction is completed. We argue that contract motherhood should not be organized according to the norms of the gift relationship, and that contract mothers should be compensated for their labour. However, we accept that there are good reasons for rejecting the commercial model as a suitable framework for contract pregnancy, and argue, instead, in favour of viewing it as a profession. © 2012 John Wiley & Sons Ltd.

  5. Muscle contraction history: modified Hill versus an exponential decay model.

    PubMed

    Ettema, G J; Meijer, K

    2000-12-01

    In recent years, it has been recognised that improvements to classic models of muscle mechanical behaviour are often necessary for properly modelling coordinated multi-joint actions. In this respect, the purpose of the present study was to improve on modelling stretch-induced force enhancement and shortening-induced force depression of muscle contraction. For this purpose, two models were used: a modified Hill model and a model based loosely on mechano-chemistry of the cross-bridge cycle (exponential decay model). The models were compared with a classic Hill modeland experimental data. Parameter values were based, as much as possible, on experimental findings in the literature, and tested with new experiments on the gastrocnemius of the rat. Both models describe many features of slow-ramp movements well during short contractions (300-500 ms), but long-duration behaviour is described only partly. The exponential decay model does not incorporate a force-velocity curve. Therefore, its good performance indicates that the status ofthe classic force-velocity characteristic may have to be reconsidered. Like movement-induced force depression and enhancement, it seems a particular manifestation of time-dependent force behaviour of muscle, rather than a fundamental property of muscle (like the length-tension curve). It is argued that a combination of the exponential decay model (or other models based on the mechano-chemistry of contraction) and structurally based models may be fruitful in explaining this time-dependent contraction behaviour. Furthermore, not in the least because of its relative simplicity, the exponential decay model may prove more suitable for modelling multi-joint movements than the Hill model.

  6. Limiting case of modified electroweak model for contracted gauge group

    SciTech Connect

    Gromov, N. A.

    2011-06-15

    The modification of the Electroweak Model with 3-dimensional spherical geometry in the matter fields space is suggested. The Lagrangian of this model is given by the sum of the free (without any potential term) matter fields Lagrangian and the standard gauge fields Lagrangian. The vector boson masses are generated by transformation of this Lagrangian from Cartesian coordinates to coordinates on the sphere S{sup 3}. The limiting case of the bosonic part of the modified model, which corresponds to the contracted gauge group SU(2; j) x U(1) is discussed. Within framework of the limit model Z boson and electromagnetic fields can be regarded as external ones with respect to W-boson fields in the sence that W-boson fields do not effect on these external fields. The masses of all particles of the Electroweak Model remain the same, but field interactions in contracted model are more simple as compared with the standard Electroweak Model.

  7. Student Mental Models Related to Expansion and Contraction

    ERIC Educational Resources Information Center

    Kurnaz, Mehmet Altan; Emen, Ayse Yagmur

    2014-01-01

    Following up on the effects of learning environments is essential to learning. The aim of this study was to examine students' mental models related to the concepts of expansion and contraction of materials. The population of the case study consisted of 155 students in a city center in Turkey. The data was gathered using open-ended questions that…

  8. Multiscale forward electromagnetic model of uterine contractions during pregnancy

    PubMed Central

    2012-01-01

    Background Analyzing and monitoring uterine contractions during pregnancy is relevant to the field of reproductive health assessment. Its clinical importance is grounded in the need to reliably predict the onset of labor at term and pre-term. Preterm births can cause health problems or even be fatal for the fetus. Currently, there are no objective methods for consistently predicting the onset of labor based on sensing of the mechanical or electrophysiological aspects of uterine contractions. Therefore, modeling uterine contractions could help to better interpret such measurements and to develop more accurate methods for predicting labor. In this work, we develop a multiscale forward electromagnetic model of myometrial contractions during pregnancy. In particular, we introduce a model of myometrial current source densities and compute its magnetic field and action potential at the abdominal surface, using Maxwell’s equations and a four-compartment volume conductor geometry. To model the current source density at the myometrium we use a bidomain approach. We consider a modified version of the Fitzhugh-Nagumo (FHN) equation for modeling ionic currents in each myocyte, assuming a plateau-type transmembrane potential, and we incorporate the anisotropic nature of the uterus by designing conductivity-tensor fields. Results We illustrate our modeling approach considering a spherical uterus and one pacemaker located in the fundus. We obtained a travelling transmembrane potential depolarizing from −56 mV to −16 mV and an average potential in the plateau area of −25 mV with a duration, before hyperpolarization, of 35 s, which is a good approximation with respect to the average recorded transmembrane potentials at term reported in the technical literature. Similarly, the percentage of myometrial cells contracting as a function of time had the same symmetric properties and duration as the intrauterine pressure waveforms of a pregnant human myometrium at term

  9. Far-field contractional polarity changes in models and nature

    NASA Astrophysics Data System (ADS)

    Munteanu, Ioan; Willingshofer, Ernst; Matenco, Liviu; Sokoutis, Dimitrios; Cloetingh, Sierd

    2014-06-01

    A change in contractional polarity occurs when the direction of tectonic transport switches along strike. This switch is conditioned by lateral variations in rheology or inherited asymmetries, such as contrasts in structure or changes in the polarity of subduction zones. The parameters controlling contractional polarity changes are less understood in situations when the strain is transferred at large distances from indenters. Analysing this type of strain transfer is critical for understanding the mechanics of thrusting in fore- or back-arc settings of orogenic areas. Comparison of crustal-scale analogue modelling with the inversion of the Black Sea back-arc and the formation of the New Guinea-New Britain fore-arc suggest that far-field changes in contractional polarity are related to rheological contrasts across inherited normal faults. The initial extension creates rheological weak zones that localize the subsequent far-field contractional deformation along groups of thrusts with opposite vergence along the strike of the system. The largest amount of far-field contractional deformation is recorded in the transfer zone located between the two indenters moving in opposite directions and is particularly high when inverting oblique extensional systems.

  10. The Contracting Support Brigade: Is It Capable of Sustaining Tempo and Combat Power in the Operational Environment

    DTIC Science & Technology

    2015-05-21

    Approved for public release; distribution is unlimited. The Contracting Support Brigade: Is it capable of Sustaining Tempo and Combat Power in the...comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE...SUBTITLE The Contracting Support Brigade: Is it Capable of Sustaining Tempo and Combat Power in the Operational Environment? 5a. CONTRACT NUMBER 5b

  11. Contraction limits of the proton-neutron symplectic model

    NASA Astrophysics Data System (ADS)

    Ganev, H. G.

    2016-01-01

    The algebraic approach to nuclear structure physics allows a certain microscopic collective motion algebra to be also interpreted on macroscopic level which is achieved in the limit of large representation quantum numbers. Such limits are referred to as macroscopic or hydrodynamic limits and show how a given microscopic discrete system starts to behave like a continuous fluid. In the present paper, two contraction limits of the recently introduced fully microscopic proton-neutron symplectic model (PNSM) with the Sp(12; R) dynamical symmetry algebra are considered. As a result, two simplified macroscopic models of nuclear collective motion are obtained in simple geometrical terms. The first one is the U(6)-phonon model with the semi-direct product structure [HW(21)]U(6), which is shown to be actually an alternative formulation of the original proton-neutron symplectic model in the familiar IBM-terms. The second model which appears in double contraction limit is the two-rotor model with the ROTp(3) ⊗ ROTn(3) ⊃ ROT(3) algebraic structure. The latter, in contrast to the original two-rotor model, is not restricted to the case of two coupled axial rotors. In this way, the second contraction limit of the PNSM, provides the phenomenological two-rotor model with a simple microscopic foundation.

  12. The 1990 GP contract: modelling variation in minor surgery provision.

    PubMed

    Silcock, J; Ratcliffe, J

    1995-01-01

    Logistic regression was used to determine the extent to which general medical practices undertake the maximum amount of minor surgery activity allowed for in the GP contract. Data on activity for 89 practices in the Grampian region of Scotland was available for two consecutive financial years: 1992-93 and 1993-94. Comparison of the regression models developed in each year showed that rural location and practice size were consistently associated with the maximization of minor surgery activity under the terms of 1990 GP Contract. In 1993-94 practices with a greater proportion of deprived patients were also more likely to be 'maximizers'. Quantitative modelling allows the performance of GPs to be assessed and also helps to identify factors which are a barrier to service development. It seems likely that, in Grampian, GPs who were able to exploit fully the provisions of their contract were those whose patients had the greatest capacity to benefit from minor surgery. Currently the GP contract is nationally negotiated, but in the future local negotiated remuneration is likely to become widespread. Modelling will have an important role in the design and monitoring of incentive structures, and help to ensure that service provision equates to local needs.

  13. 25 CFR 170.607 - Can a tribe use its allocation of IRR Program funds for contract support costs?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Can a tribe use its allocation of IRR Program funds for... Miscellaneous Provisions § 170.607 Can a tribe use its allocation of IRR Program funds for contract support costs? Yes. Contract support costs are an eligible item out of a tribe's IRR Program allocation and...

  14. In vitro models of tail contraction and cytoplasmic streaming in amoeboid cells.

    PubMed

    Janson, L W; Taylor, D L

    1993-10-01

    We have developed a reconstituted gel-sol and contractile model system that mimics the structure and dynamics found at the ectoplasm/endoplasm interface in the tails of many amoeboid cells. We tested the role of gel-sol transformations of the actin-based cytoskeleton in the regulation of contraction and in the generation of endoplasm from ectoplasm. In a model system with fully phosphorylated myosin II, we demonstrated that either decreasing the actin filament length distribution or decreasing the extent of actin filament cross-linking initiated both a weakening of the gel strength and contraction. However, streaming of the solated gel components occurred only under conditions where the length distribution of actin was decreased, causing a self-destruct process of continued solation and contraction of the gel. These results offer significant support that gel strength plays an important role in the regulation of actin/myosin II-based contractions of the tail cortex in many amoeboid cells as defined by the solation-contraction coupling hypothesis (Taylor, D. L., and M. Fechheimer. 1982. Phil. Trans. Soc. Lond. B. 299:185-197). The competing processes of solation and contraction of the gel would appear to be mutually exclusive. However, it is the temporal-spatial balance of the rate and extent of two stages of solation, coupled to contraction, that can explain the conversion of gelled ectoplasm in the tail to a solated endoplasm within the same small volume, generation of a force for the retraction of tails, maintenance of cell polarity, and creation of a positive hydrostatic pressure to push against the newly formed endoplasm. The mechanism of solation-contraction of cortical cytoplasm may be a general component of the normal movement of a variety of amoeboid cells and may also be a component of other contractile events such as cytokinesis.

  15. Acquisition Research Program: Creating Synergy for Informed Change. Service Contracting - Support to Commander, Naval Installations Command

    DTIC Science & Technology

    2007-05-01

    Metrics available internally to the Command – Potential to link to CFMS • Develop Business Intelligence Standardize BOS Contracting Delivery Model 12...Procurement- Related Operating Expense Reduced Non-Procurement Related Operating Expense i ti / l ti / Demand Management • Improve business ... intelligence regarding spend practices, cycle time and processes • Eliminate demand • Reduce consumption • Encourage substitution • Change product mix

  16. Command and Control of Civilian Contract Manned Navy Fleet Support and Military Sealift Command Ships.

    DTIC Science & Technology

    1983-12-01

    members. J B. NMEBA POSrIIN On 25 April 1983, the president of the NAM, Mr. Jesse M. Calhoon , testified before the House Armed Services Cammittee’s...Maritime Administration 25 Ii In his testiny, Mr. Calhoon argued that civilian contract operation of Navy and MSC fleet support ships was in the...the number of merchant seamen who are trained and ready to serve with the Navy. C. CIVILIAN CCNTRACT MANNING PRCOPSAL In his testimony, Mr. Calhoon

  17. On the application of copula in modeling maintenance contract

    NASA Astrophysics Data System (ADS)

    Iskandar, B. P.; Husniah, H.

    2016-02-01

    This paper deals with the application of copula in maintenance contracts for a nonrepayable item. Failures of the item are modeled using a two dimensional approach where age and usage of the item and this requires a bi-variate distribution to modelling failures. When the item fails then corrective maintenance (CM) is minimally repaired. CM can be outsourced to an external agent or done in house. The decision problem for the owner is to find the maximum total profit whilst for the agent is to determine the optimal price of the contract. We obtain the mathematical models of the decision problems for the owner as well as the agent using a Nash game theory formulation.

  18. Support effects studied on model supported catalysts

    SciTech Connect

    Gorte, R.G.

    1991-11-01

    We are studying model catalysts in which the active phase is deposited onto flat oxide substrates in order to understand how a catalyst is affected by its support. We have examined the following growth and stability of titania overlayers which had been vapor deposited onto a Rh foil; the growth of Pt films on ZnO(0001)Zn and O(0001)O and compared the results to those obtained for Pt on {alpha}-Al{sub 2}O{sub 3}(0001). Samples were prepared by vapor deposition of Pt onto flat substrates in ultra high vacuum, and metal coverages were measured using a quartz-crystal, film thickness monitor; the structure and CO adsorption properties of Pt films vapor deposited onto a ZrO{sub 2}(100) crystal; the deposition of Rh on a ZrO{sub 2}(100) crystal; The absorption of NO on Pt particles supported on CeO{sub 2}, {alpha}-Al{sub 2}O{sub 3}(0001), and the Zn- and O-polar surfaces of ZnO(0001). We have investigated supported oxides in order to understand the acidic properties that have been reported for monolayer oxides. Our first studies were of amorphous, silicalumina catalysts. Finally, we have also begun to prepare model supported oxides in order to be able to used spectroscopic methods to characterize the sites formed on these materials. Our first studies were of niobia deposition on oxidized Al films and on an {alpha}-Al{sub 2}O{sub 3}(0001) crystal.

  19. Improved Cell Culture Method for Growing Contracting Skeletal Muscle Models

    NASA Technical Reports Server (NTRS)

    Marquette, Michele L.; Sognier, Marguerite A.

    2013-01-01

    An improved method for culturing immature muscle cells (myoblasts) into a mature skeletal muscle overcomes some of the notable limitations of prior culture methods. The development of the method is a major advance in tissue engineering in that, for the first time, a cell-based model spontaneously fuses and differentiates into masses of highly aligned, contracting myotubes. This method enables (1) the construction of improved two-dimensional (monolayer) skeletal muscle test beds; (2) development of contracting three-dimensional tissue models; and (3) improved transplantable tissues for biomedical and regenerative medicine applications. With adaptation, this method also offers potential application for production of other tissue types (i.e., bone and cardiac) from corresponding precursor cells.

  20. Military Operations: DOD Needs to Address Contract Oversight and Quality Assurance Issues for Contracts Used to Support Contingency Operations

    DTIC Science & Technology

    2008-09-01

    equipment, changes in host country labor laws , and paying for work to be performed multiple times. For six of the contracts we reviewed, the cost of... labor laws , and (4) having to pay for work to be performed multiple times because it did not meet required standards. First, we found that in three of...associated overhead expenses.22 Third, changes in the host country labor law resulted in additional security services contract costs. According to the

  1. Motor unit activity when young and old adults perform steady contractions while supporting an inertial load.

    PubMed

    Pascoe, Michael A; Gould, Jeffrey R; Enoka, Roger M

    2013-02-01

    The purpose of the study was to compare the discharge characteristics of biceps brachii motor units of young and old adults when they performed steady, submaximal contractions while the arm supported different inertial loads. Young (28 ± 4 yr; n = 16) and old (75 ± 4 yr; n = 14) adults performed steady contractions with the elbow flexors at target forces set at either small (11.7 ± 4.4% maximum) or large (17.8 ± 6.5% maximum) differences below the recruitment threshold force of the motor unit (n = 40). The task was to maintain an elbow angle at 1.57 rad until the motor unit was recruited and discharged action potentials for ∼120 s. Time to recruitment was longer for the larger target force difference (187 ± 227 s vs. 23 ± 46 s, P < 0.001). Once recruited, motor units discharged action potentials either repetitively or intermittently, with a greater proportion of motor units exhibiting the repetitive pattern for old adults. Discharge rate at recruitment and during the steady contraction was similar for the two target force differences for old adults but was greater for the small target force difference for young adults. Discharge variability was similar at recruitment for the two age groups but less for the old adults during the steady contraction. The greatest difference between the present results and those reported previously when the arm pulled against a rigid restraint was that old adults modulated discharge rate less than young adults across the two contraction intensities for both load types.

  2. Mathematical model of mouse embryonic cardiomyocyte excitation-contraction coupling.

    PubMed

    Korhonen, Topi; Rapila, Risto; Tavi, Pasi

    2008-10-01

    Excitation-contraction (E-C) coupling is the mechanism that connects the electrical excitation with cardiomyocyte contraction. Embryonic cardiomyocytes are not only capable of generating action potential (AP)-induced Ca(2+) signals and contractions (E-C coupling), but they also can induce spontaneous pacemaking activity. The spontaneous activity originates from spontaneous Ca(2+) releases from the sarcoplasmic reticulum (SR), which trigger APs via the Na(+)/Ca(2+) exchanger (NCX). In the AP-driven mode, an external stimulus triggers an AP and activates voltage-activated Ca(2+) intrusion to the cell. These complex and unique features of the embryonic cardiomyocyte pacemaking and E-C coupling have never been assessed with mathematical modeling. Here, we suggest a novel mathematical model explaining how both of these mechanisms can coexist in the same embryonic cardiomyocytes. In addition to experimentally characterized ion currents, the model includes novel heterogeneous cytosolic Ca(2+) dynamics and oscillatory SR Ca(2+) handling. The model reproduces faithfully the experimentally observed fundamental features of both E-C coupling and pacemaking. We further validate our model by simulating the effect of genetic modifications on the hyperpolarization-activated current, NCX, and the SR Ca(2+) buffer protein calreticulin. In these simulations, the model produces a similar functional alteration to that observed previously in the genetically engineered mice, and thus provides mechanistic explanations for the cardiac phenotypes of these animals. In general, this study presents the first model explaining the underlying cellular mechanism for the origin and the regulation of the heartbeat in early embryonic cardiomyocytes.

  3. Mathematical Model of Mouse Embryonic Cardiomyocyte Excitation–Contraction Coupling

    PubMed Central

    Korhonen, Topi; Rapila, Risto; Tavi, Pasi

    2008-01-01

    Excitation–contraction (E–C) coupling is the mechanism that connects the electrical excitation with cardiomyocyte contraction. Embryonic cardiomyocytes are not only capable of generating action potential (AP)-induced Ca2+ signals and contractions (E–C coupling), but they also can induce spontaneous pacemaking activity. The spontaneous activity originates from spontaneous Ca2+ releases from the sarcoplasmic reticulum (SR), which trigger APs via the Na+/Ca2+ exchanger (NCX). In the AP-driven mode, an external stimulus triggers an AP and activates voltage-activated Ca2+ intrusion to the cell. These complex and unique features of the embryonic cardiomyocyte pacemaking and E–C coupling have never been assessed with mathematical modeling. Here, we suggest a novel mathematical model explaining how both of these mechanisms can coexist in the same embryonic cardiomyocytes. In addition to experimentally characterized ion currents, the model includes novel heterogeneous cytosolic Ca2+ dynamics and oscillatory SR Ca2+ handling. The model reproduces faithfully the experimentally observed fundamental features of both E–C coupling and pacemaking. We further validate our model by simulating the effect of genetic modifications on the hyperpolarization-activated current, NCX, and the SR Ca2+ buffer protein calreticulin. In these simulations, the model produces a similar functional alteration to that observed previously in the genetically engineered mice, and thus provides mechanistic explanations for the cardiac phenotypes of these animals. In general, this study presents the first model explaining the underlying cellular mechanism for the origin and the regulation of the heartbeat in early embryonic cardiomyocytes. PMID:18794378

  4. Filial piety by contract? The emergence, implementation, and implications of the "family support agreement" in China.

    PubMed

    Chou, Rita Jing-Ann

    2011-02-01

    China has the largest aging population in the world today. Despite the Chinese tradition of filial piety, economic, social, cultural, and familial changes have made it increasingly difficult for older Chinese to receive support from adult children. To ensure parental support, the Family Support Agreement (FSA) emerged from a local community in the mid-1980s. Since then, the FSA has been promoted and monitored by the government. By the end of 2005, FSAs had been signed by more than 13 million rural families across China and is now finding its way into cities. A voluntary contract between older parents and adult children concerning parental provisions, the FSA represents an innovation to help meet the challenge of providing elder support. Although the FSA's moral persuasion is based on filial piety, violations of the FSA are subject to penalties by law. As the first systematic and comprehensive exploratory study on the FSA, this article examines (a) the FSA's emergence, content, legal foundation, and implementation; (b) the role of the government and the legal system in promoting or monitoring FSAs; (c) the FSA's strengths, limitations, and challenges; (d) the FSA's implications in light of Chinese history, intergenerational contract, filial piety, and intergenerational relations; and (e) the future of the FSA as a social policy.

  5. 25 CFR 170.607 - Can a tribe use its allocation of IRR Program funds for contract support costs?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Service Delivery for Indian Reservation Roads... costs? Yes. Contract support costs are an eligible item out of a tribe's IRR Program allocation and...

  6. Numerical modelling of the angiogenesis process in wound contraction.

    PubMed

    Valero, C; Javierre, E; García-Aznar, J M; Gómez-Benito, M J

    2013-04-01

    Angiogenesis consists of the growth of new blood vessels from the pre-existing vasculature. This phenomenon takes place in several biological processes, including wound healing. In this work, we present a mathematical model of angiogenesis applied to skin wound healing. The developed model includes biological (capillaries and fibroblasts), chemical (oxygen and angiogenic growth factor concentrations) and mechanical factors (cell traction forces and extracellular matrix deformation) that influence the evolution of the healing process. A novelty from previous works, apart from the coupling of angiogenesis and wound contraction, is the more realistic modelling of skin as a hyperelastic material. Large deformations are addressed using an updated Lagrangian approach. The coupled non-linear model is solved with the finite element method, and the process is studied over two wound geometries (circular and elliptical) of the same area. The results indicate that the elliptical wound vascularizes two days earlier than the circular wound but that they experience a similar contraction level, reducing its size by 25 %.

  7. 10 CFR 950.14 - Standby Support Contract: Covered events, exclusions, covered delay and covered cost provisions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... SUPPORT FOR CERTAIN NUCLEAR PLANT DELAYS Standby Support Contract Process § 950.14 Standby Support..., including but not limited to delays attributable to the following types of events: (i) Project planning and... criteria in accordance with its schedule; or (iv) The lack of adequate funding for construction and testing...

  8. 10 CFR 950.14 - Standby Support Contract: Covered events, exclusions, covered delay and covered cost provisions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... SUPPORT FOR CERTAIN NUCLEAR PLANT DELAYS Standby Support Contract Process § 950.14 Standby Support... of the advanced nuclear facility. (3) Normal business risks, including but not limited to the... meaning the seizure or destruction of property by order of governmental authority; (iii) War or military...

  9. Mathematical model for isometric and isotonic muscle contractions.

    PubMed

    De Vita, R; Grange, R; Nardinocchi, P; Teresi, L

    2017-07-21

    A new mathematical model is presented to describe both the active and passive mechanics of muscles. In order to account for the active response, a two-layer kinematics that introduces both the visible and rest lengths of the muscle is presented within a rational mechanics framework. The formulation is based on an extended version of the principle of virtual power and the dissipation principle. By using an accurate constitutive description of muscle mobility under activation, details of microscopic processes that lead to muscle contraction are glossed over while macroscopic effects of chemical/electrical stimuli on muscle mechanics are retained. The model predictions are tested with isometric and isotonic experimental data collected from murine extensor digitorum muscle. It is shown that the proposed model captures experimental observations with only three scalar parameters. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Rhode Island Model Evaluation & Support System: Support Professional. Edition II

    ERIC Educational Resources Information Center

    Rhode Island Department of Education, 2015

    2015-01-01

    Rhode Island educators believe that implementing a fair, accurate, and meaningful evaluation and support system for support professionals will help improve student outcomes. The primary purpose of the Rhode Island Model Support Professional Evaluation and Support System (Rhode Island Model) is to help all support professionals do their best work…

  11. Modeling the contraction of the pelvic floor muscles.

    PubMed

    Brandão, Fernanda Sofia Quintela da Silva; Parente, Marco Paulo Lages; Rocha, Paulo Alexandre Gomes Gonçalves; Saraiva, Maria Teresa da Quinta E Costa de Mascarenhas; Ramos, Isabel Maria Amorim Pereira; Natal Jorge, Renato Manuel

    2016-01-01

    We performed numerical simulation of voluntary contraction of the pelvic floor muscles to evaluate the resulting displacements of the organs and muscles. Structures were segmented in Magnetic Resonance (MR) images. Different material properties and constitutive models were attributed. The Finite Element Method was applied, and displacements were compared with dynamic MRI findings. Numerical simulation showed muscle magnitude displacement ranging from 0 to 7.9 mm, more evident in the posterior area. Accordingly, the anorectum moved more than the uterus and bladder. Dynamic MRI showed less 0.2 mm and 4.1 mm muscle dislocation in the anterior and cranial directions, respectively. Applications of this model include evaluating muscle impairment, subject-specific mesh implant planning, or effectiveness of rehabilitation.

  12. Effective Team Support: From Modeling to Software Agents

    NASA Technical Reports Server (NTRS)

    Remington, Roger W. (Technical Monitor); John, Bonnie; Sycara, Katia

    2003-01-01

    The purpose of this research contract was to perform multidisciplinary research between CMU psychologists, computer scientists and engineers and NASA researchers to design a next generation collaborative system to support a team of human experts and intelligent agents. To achieve robust performance enhancement of such a system, we had proposed to perform task and cognitive modeling to thoroughly understand the impact technology makes on the organization and on key individual personnel. Guided by cognitively-inspired requirements, we would then develop software agents that support the human team in decision making, information filtering, information distribution and integration to enhance team situational awareness. During the period covered by this final report, we made substantial progress in modeling infrastructure and task infrastructure. Work is continuing under a different contract to complete empirical data collection, cognitive modeling, and the building of software agents to support the teams task.

  13. Contracts for field projects and supporting research on enhanced oil recovery. Progress review number 86, quarter ending March 31, 1996

    SciTech Connect

    1997-05-01

    Summaries are presented for 37 enhanced oil recovery contracts being supported by the Department of Energy. The projects are grouped into gas displacement methods, thermal recovery methods, geoscience technology, reservoir characterization, and field demonstrations in high-priority reservoir classes. Each summary includes the objectives of the project and a summary of the technical progress, as well as information on contract dates, size of award, principal investigator, and company or facility doing the research.

  14. A resource-dependence model of hospital contract management.

    PubMed Central

    Alexander, J A; Morrisey, M A

    1989-01-01

    This study empirically examines the determinants of hospital entry into management contracts with multihospital systems. Using a resource-dependence framework, the study tests whether market conditions, regulatory climate, management effectiveness, and certain enabling factors affect the probability of hospital entry into a contract management arrangement. The study used a pooled sample of 312 contract-managed and 936 traditionally managed hospitals. Results suggest the importance of management effectiveness, regulatory climate, and hospital ownership (investor owned or nonprofit) as predisposing conditions of contract management. PMID:2732059

  15. An electro-mechanical multiscale model of uterine pregnancy contraction.

    PubMed

    Yochum, Maxime; Laforêt, Jérémy; Marque, Catherine

    2016-10-01

    Detecting preterm labor as early as possible is important because tocolytic drugs are much more likely to delay preterm delivery if administered early. Having good information on the real risk of premature labor also leads to fewer women who do not need aggressive treatment for premature labor threat. Currently, one of the most promising ways to diagnose preterm labor threat is the analysis of the electrohysterogram (EHG). Its characteristics have been related to preterm labor risk but they have not proven to be sufficiently accurate to use in clinical routine. One of the reasons for this is that the physiology of the pregnant uterus is insufficiently understood. Models already exist in literature that simulate either the electrical or the mechanical component of the uterine smooth muscle. Few include both components in a co-simulation of electrical and mechanical aspects. A model that can represent realistically both the electrical and the mechanical behavior of the uterine muscle could be useful for better understanding the EHG and therefore for preterm labor detection. Processing the EHG considers only the electrical component of the uterus but the electrical activity does not seem to explain by itself the synchronization of the uterine muscle that occurs during labor and not at other times. Recent studies have demonstrated that the mechanical behavior of the uterine muscle seems to play an important role in uterus synchronization during labor. The aim of the proposed study is to link three different models of the uterine smooth muscle behavior by using co-simulation. The models go from the electrical activity generated at the cellular level to the mechanical force generated by the muscle and from there to the deformation of the tissue. The results show the feasibility of combining these three models to model a whole uterus contraction on 3D realistic uterus model. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Sequenced Contractions and Abbreviations for Model 2 Reading.

    ERIC Educational Resources Information Center

    Cronnell, Bruce

    The nature and use of contractions and abbreviations in beginning reading is discussed and applied to the Southwest Regional Laboratory (SWRL) Mod 2 Reading Program, a four-year program (K-3) for teaching reading skills to primary-grade children. The contractions and abbreviations are listed and sequenced for the reading program. The results of…

  17. Theory and Modeling in Support of Tether

    NASA Technical Reports Server (NTRS)

    Chang, C. L.; Bergeron, G.; Drobot, A. D.; Papadopoulos, K.; Riyopoulos, S.; Szuszczewicz, E.

    1999-01-01

    This final report summarizes the work performed by SAIC's Applied Physics Operation on the modeling and support of Tethered Satellite System missions (TSS-1 and TSS-1R). The SAIC team, known to be Theory and Modeling in Support of Tether (TMST) investigation, was one of the original twelve teams selected in July, 1985 for the first TSS mission. The accomplishments described in this report cover the period December 19, 1985 to September 31, 1999 and are the result of a continuous effort aimed at supporting the TSS missions in the following major areas. During the contract period, the SAIC's TMST investigation acted to: Participate in the planning and the execution on both of the TSS missions; Provide scientific understanding on the issues involved in the electrodynamic tether system operation prior to the TSS missions; Predict ionospheric conditions encountered during the re-flight mission (TSS-lR) based on realtime global ionosounde data; Perform post mission analyses to enhance our understanding on the TSS results. Specifically, we have 1) constructed and improved current collection models and enhanced our understanding on the current-voltage data; 2) investigated the effects of neutral gas in the current collection processes; 3) conducted laboratory experiments to study the discharge phenomena during and after tether-break; and 4) perform numerical simulations to understand data collected by plasma instruments SPES onboard the TSS satellite; Design and produce multi-media CD that highlights TSS mission achievements and convey the knowledge of the tether technology to the general public. Along with discussions of this work, a list of publications and presentations derived from the TMST investigation spanning the reporting period is compiled.

  18. Modeling Advance Life Support Systems

    NASA Technical Reports Server (NTRS)

    Pitts, Marvin; Sager, John; Loader, Coleen; Drysdale, Alan

    1996-01-01

    Activities this summer consisted of two projects that involved computer simulation of bioregenerative life support systems for space habitats. Students in the Space Life Science Training Program (SLSTP) used the simulation, space station, to learn about relationships between humans, fish, plants, and microorganisms in a closed environment. One student complete a six week project to modify the simulation by converting the microbes from anaerobic to aerobic, and then balancing the simulation's life support system. A detailed computer simulation of a closed lunar station using bioregenerative life support was attempted, but there was not enough known about system restraints and constants in plant growth, bioreactor design for space habitats and food preparation to develop an integrated model with any confidence. Instead of a completed detailed model with broad assumptions concerning the unknown system parameters, a framework for an integrated model was outlined and work begun on plant and bioreactor simulations. The NASA sponsors and the summer Fell were satisfied with the progress made during the 10 weeks, and we have planned future cooperative work.

  19. Contracts and Management Services FY 1996 Site Support Program Plan: WBS 6.10.14. Revision 1

    SciTech Connect

    Knoll, J.M. Jr.

    1995-09-01

    This is the Contracts and Management Services site support program plan for the US DOE Hanford site. The topics addressed in the program plan include a mission statement, program objectives, planning assumptions, program constraints, work breakdown structure, milestone list, milestone description sheets, and activity detail including cost accounting narrative summary, approved funding budget, and activity detailed description.

  20. 25 CFR 170.608 - Can a tribe pay contract support costs from Department of the Interior or BIA appropriations?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Can a tribe pay contract support costs from Department of the Interior or BIA appropriations? 170.608 Section 170.608 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Service Delivery for...

  1. 25 CFR 170.607 - Can a tribe use its allocation of IRR Program funds for contract support costs?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Can a tribe use its allocation of IRR Program funds for contract support costs? 170.607 Section 170.607 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Service Delivery for Indian Reservation...

  2. 48 CFR 5152.245-9001 - Government property for installation support services (cost-reimbursement contracts).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... the Contracting Officer determines that it is so permanently attached that removal would cause... normal parts replacement), and repair the property in accordance with sound industrial practice. (2) No... shall notify the Contracting Officer in writing when sound industrial practice requires maintenance...

  3. Model Contract of Employment for Principals, Assistant Principals. Administrative Information Report.

    ERIC Educational Resources Information Center

    Epstein, Benjamin; Hersey, Paul W.

    This publication presents a model employment contract intended to assist school administrators in developing or modifying appropriate contract language to protect the status of school principals and assistant principals. Although the model was developed specifically for secondary school administrators, it would be equally appropriate for…

  4. Support effects studied on model supported catalysts. Progress report

    SciTech Connect

    Gorte, R.J.

    1993-02-01

    Composition and structure of oxide support materials can change the catalytic behavior of metal and oxide catalysts. Model catalysts are being studied in which the active phase is deposited on flat oxide substrates, with emphasis on metals catalysis for automotive emissions control and acidity in supported oxides. Research is reported in the following areas: particle-size effects, support effects on ZnO and zirconia, support effects on ceria, supported oxides, and low energy ion scattering (no results in the latter).

  5. Injectable polyurethane composite scaffolds delay wound contraction and support cellular infiltration and remodeling in rat excisional wounds.

    PubMed

    Adolph, Elizabeth J; Hafeman, Andrea E; Davidson, Jeffrey M; Nanney, Lillian B; Guelcher, Scott A

    2012-02-01

    Injectable scaffolds present compelling opportunities for wound repair and regeneration because of their ability to fill irregularly shaped defects and deliver biologics such as growth factors. In this study, we investigated the properties of injectable polyurethane (PUR) biocomposite scaffolds and their application in cutaneous wound repair using a rat excisional model. The scaffolds have a minimal reaction exotherm and clinically relevant working and setting times. Moreover, the biocomposites have mechanical and thermal properties consistent with rubbery elastomers. In the rat excisional wound model, injection of settable biocomposite scaffolds stented the wounds at early time points, resulting in a regenerative rather than a scarring phenotype at later time points. Measurements of wound length and thickness revealed that the treated wounds were less contracted at day 7 compared to blank wounds. Analysis of cell proliferation and apoptosis showed that the scaffolds were biocompatible and supported tissue ingrowth. Myofibroblast formation and collagen fiber organization provided evidence that the scaffolds have a positive effect on extracellular matrix remodeling by disrupting the formation of an aligned matrix under elevated tension. In summary, we have developed an injectable biodegradable PUR biocomposite scaffold that enhances cutaneous wound healing in a rat model.

  6. Injectable Polyurethane Composite Scaffolds Delay Wound Contraction and Support Cellular Infiltration and Remodeling in Rat Excisional Wounds

    PubMed Central

    Adolph, Elizabeth J.; Hafeman, Andrea E.; Davidson, Jeffrey M.; Nanney, Lillian B.; Guelcher, Scott A.

    2011-01-01

    Injectable scaffolds present compelling opportunities for wound repair and regeneration due to their ability to fill irregularly shaped defects and deliver biologics such as growth factors. In this study, we investigated the properties of injectable polyurethane biocomposite scaffolds and their application in cutaneous wound repair using a rat excisional model. The scaffolds have a minimal reaction exotherm and clinically relevant working and setting times. Moreover, the biocomposites have mechanical and thermal properties consistent with rubbery elastomers. In the rat excisional wound model, injection of settable biocomposite scaffolds stented the wounds at early time points, resulting in a regenerative rather than a scarring phenotype at later time points. Measurements of wound width and thickness revealed that the treated wounds were less contracted at day 7 compared to blank wounds. Analysis of cell proliferation and apoptosis showed that the scaffolds were biocompatible and supported tissue ingrowth. Myofibroblast formation and collagen fiber organization provided evidence that the scaffolds have a positive effect on extracellular matrix remodeling by disrupting the formation of an aligned matrix under elevated tension. In summary, we have developed an injectable biodegradable polyurethane biocomposite scaffold that enhances cutaneous wound healing in a rat model. PMID:22105887

  7. The phenomenological model of muscle contraction with a controller to simulate the excitation-contraction (E-C) coupling.

    PubMed

    Tamura, Youjiro; Saito, Masami; Ito, Akira

    2009-02-09

    We previously proposed a systematic motor model for muscle with two parallel Maxwell elements and a force generator P. The motor model showed the non-linear behavior of a muscle, such as the force-velocity relation and the force depression and enhancement, by using weight functions. Our newly proposed muscle model is based on the molecular mechanism of myosin cross-bridges. We assume that each parallel Maxwell element represents the mechanical properties of weak and strong binding of the myosin head to actin. Furthermore, we introduce a controller to simulate the excitation-contraction coupling of the muscle. The new muscle model satisfies all the properties obtained in our previous model and reduces the wasted energy of the viscous component to less than 5% of the total energy. The controller enables us to simulate contractions of slow and fast twitch muscles, which are driven by an artificial action potential or a processing electromyography signal despite their same mechanical components. The maximum velocities are calculated to be 3.4L(0)m/s for the fast twitch muscle model and 2.5L(0)m/s for the slow twitch muscle model, where L(0) is the initial length of the muscle model.

  8. Hemodynamic effects of pressure-volume relation in the atrial contraction model on the total artificial heart using centrifugal blood pumps.

    PubMed

    Shiga, Takuya; Kuroda, Takehito; Tsuboko, Yusuke; Miura, Hidekazu; Shiraishi, Yasuyuki; Yambe, Tomoyuki

    2013-01-01

    Hemodynamic effects of atrial contraction with centrifugal pump type total artificial heart is unknown. In this study, we simulated an atrial contraction in a mock model. By the driving condition with higher pressure in the mock atrial model, the load during atrial contraction increased. Based on these findings, we examined atrial contraction in the animal using adult goats. Prior to the measurement, we installed a centrifugal-type ventricular assist device (VADs), and then clamped both ventricles. We measured the hemodynamic data without ventricular contractile functions in order to obtain the effect of atrial contraction on hemodynamics under the condition of the total artificial heart (TAH) circulatory support model. We could estimate the heart rate by revolution number and voltage of pumps. There might be a possibility that we could regulate autonomic nervous response with the control of cardiac output.

  9. Mechano-chemical Interactions in Cardiac Sarcomere Contraction: A Computational Modeling Study

    PubMed Central

    Lumens, Joost; Arts, Theo; Delhaas, Tammo

    2016-01-01

    We developed a model of cardiac sarcomere contraction to study the calcium-tension relationship in cardiac muscle. Calcium mediates cardiac contraction through its interactions with troponin (Tn) and subsequently tropomyosin molecules. Experimental studies have shown that a slight increase in intracellular calcium concentration leads to a rapid increase in sarcomeric tension. Though it is widely accepted that the rapid increase is not possible without the concept of cooperativity, the mechanism is debated. We use the hypothesis that there exists a base level of cooperativity intrinsic to the thin filament that is boosted by mechanical tension, i.e. a high level of mechanical tension in the thin filament impedes the unbinding of calcium from Tn. To test these hypotheses, we developed a computational model in which a set of three parameters and inputs of calcium concentration and sarcomere length result in output tension. Tension as simulated appeared in good agreement with experimentally measured tension. Our results support the hypothesis that high tension in the thin filament impedes Tn deactivation by increasing the energy required to detach calcium from the Tn. Given this hypothesis, the model predicted that the areas with highest tension, i.e. closest to the Z-disk end of the single overlap region, show the largest concentration of active Tn’s. PMID:27716775

  10. U.S. Department of Energy Office of Inspector General report on audit of Department of Energy support service contracting

    SciTech Connect

    1995-06-30

    The purpose of this audit was to review the Department`s acquisition and use of support service contractors and subcontractors. The audit objectives were to determine if the Department (1) paid fees to both support service contractors and subcontractors for services exclusively performed by subcontractors, (2) used support service contractors to perform inherent government functions, and (3) rolled over unearned award fees to subsequent evaluation periods and had adequate management controls to ensure that contractor performance would be evaluated. The Department did not always obtain support services in the most economical and effective manner. The Department negotiated and paid four of six support service contractors an estimated $5.1 million in fees for services exclusively provided by subcontractors because the Department did not have a policy which addressed the inclusion, at the pre-award phase, of subcontract labor in the support service contractors` fee determinations. Furthermore, while the authors found no instances where support service contractors performed inherent government functions, they did note that the Department maintained minimal administration over major portions of contracted-for services on three of six support service contracts. This occurred because contractors subcontracted extensively for support services. Consequently, the Department may have decreased their ability to control cost growth on these three contracts. As discussed in Part 4, the Department`s process was sufficient in five of six cases to evaluate support service contractor performance. However, one of six cost-plus-award-fee contractors received award fees that exceeded its performance ratings by $89,000 because one Departmental office elected to rollover unearned portions of fees from prior evaluation periods and make them available in the next evaluation period.

  11. A multi-agent cell-based model for wound contraction.

    PubMed

    Boon, W M; Koppenol, D C; Vermolen, F J

    2016-05-24

    A mathematical model for wound contraction is presented. The model is based on a cell-based formalism where fibroblasts, myofibroblasts and the immune reaction are taken into account. The model is used to simulate contraction of a wound using point forces on the cell boundary and it also determines the orientation of collagen after restoration of the damage. The paper presents the mathematical model in terms of the equations and assumptions, as well as some implications of the modelling. The present model predicts that the amount of final contraction is larger if the migration velocity of the leukocytes is larger and hence it is important that the immune system functions well to prevent contractures. Further, the present model is the first cell-based model that combines the immune system to final contractions.

  12. 48 CFR 5152.245-9001 - Government property for installation support services (cost-reimbursement contracts).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... property; (ii) The time and origin of the loss, destruction, or damage; (iii) All known interests in... the Contracting Officer. (9) The Contractor shall do nothing to prejudice the Government's rights...

  13. Improvements Needed in U.S. Special Operations Command Global Battlestaff and Program Support Contract Oversight

    DTIC Science & Technology

    2013-04-26

    the terms of the contract, and safeguarding USSOCOM’s interests in its contractual relationships . In addition, FAR 42.302, “Contract Administration...the life of the task order, to identify and/or develop cost factors and/or CERs [Cost Estimating Relationships ] and prepare a LCCE [Life Cycle Cost... relationship created between the Government and the contractor’s personnel. The Government is normally required to obtain its employees by direct hire

  14. U.S. Department of Defense Contract Spending and the Supporting Industrial Base, 2000-2013

    DTIC Science & Technology

    2014-04-30

    2000 –2013 David Berteau, Center for Strategic & International Studies Jesse Ellman, Center for Strategic & International Studies Gregory...Industrial Base, 2000 -2013 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f...federal contract dollars throughout the growth and subsequent inflection of defense spending of the 2000 ??? 2013 study period. This data will be analyzed

  15. The Identification of Contracting Terms in Support of the Body of Knowledge

    DTIC Science & Technology

    1990-09-01

    and 2) Secretary of Defense Cheney’s Defense Management Review. ( Loeb , 1989:2) Among its many recommendations, the Packard Commission stated that, in...individuals assigned to positions in the GS-1102, Contracting series. ( Loeb , 1989:2) The GS-1102, Contracting series referenced in the OFPP memo includes...comprised a work force of 30,263 individuals in 1988 ( Loeb , 1989:1; Report on the Acquisition Work Force, 1989:1). The importance of this series was

  16. Contracts and management services site support program plan WBS 6.10.14

    SciTech Connect

    Knoll, J.M. Jr.

    1994-09-01

    Contracts and Management Services is recognized as the central focal point for programs having company or sitewide application in pursuit of the Hanford Missions`s financial and operational objectives. Contracts and Management Services actively pursues cost savings and operational efficiencies through: Management Standards by ensuring all employees have an accessible, integrated system of clear, complete, accurate, timely, and useful management control policies and procedures; Contract Reform by restructuring the contract, organization, and cost accounting systems to refocus Hanford contract activities on output products; Systems and Operations Evaluation by directing the Cost Reduction program, Great Ideas, and Span of Management activities; Program Administration by enforcing conditions of Accountability (whether DEAR-based or FAR-based) for WHC, BCSR, ICF KH, and BHI; Contract Performance activities; chairing the WHC Cost Reduction Review Board; and analyzing companywide Performance Measures; Data Standards and Administration by establishing and directing the company data management program; giving direction to the major RL programs and mission areas for implementation of cost-effective and efficient data management practices; directing all operations, application, and interfaces contained within the Hanford PeopleCore System; directing accomplishment and delivery of TPA data management milestones; and directing the sitewide data management processes for Data Standards and the Data Directory.

  17. Alternative Education/Alternative Revenue. A. Contract Training: Public and Private Sector Models.

    ERIC Educational Resources Information Center

    Lestina, Raymond; Curry, Beverly A.

    1989-01-01

    Highlights two models of contract education, using Triton College's (IL) programs as examples. Describes Triton's Employee Development Institute, which contracts to provide specific training to local businesses, and Triton's Continuing Education Center for Health Professionals (CECHP), which co-sponsors programs for the continuing education of…

  18. A Model for and Method of Predicting High Quality Army Enlistment Contracts.

    DTIC Science & Technology

    1986-09-01

    Practice of Econometrics, John Wiley and Sons, 1982. 11. Anton , Howard , Elementary Linear Algebra , John Wiley & Sons, 1984. 12. Barr, Donald R. and...the decision maker. " 4 The thesis develops the framework for a parsimonious linear statistical model of quality enlistment contracts for the U.S. Army...develops the framework for a parsimonious linear statistical model of quality enlistment contracts for the U.S. Army. There is a need for such a model that

  19. Metric half-span model support system

    NASA Technical Reports Server (NTRS)

    Jackson, C. M., Jr.; Dollyhigh, S. M.; Shaw, D. S. (Inventor)

    1982-01-01

    A model support system used to support a model in a wind tunnel test section is described. The model comprises a metric, or measured, half-span supported by a nonmetric, or nonmeasured half-span which is connected to a sting support. Moments and forces acting on the metric half-span are measured without interference from the support system during a wind tunnel test.

  20. Multiscale Interactions in a 3D Model of the Contracting Ventricle.

    PubMed

    Amar, Ani; Zlochiver, Sharon; Barnea, Ofer

    2015-12-01

    A biophysical detailed multiscale model of the myocardium is presented. The model was used to study the contribution of interrelated cellular mechanisms to global myocardial function. The multiscale model integrates cellular electrophysiology, excitation propagation dynamics and force development models into a geometrical fiber based model of the ventricle. The description of the cellular electrophysiology in this study was based on the Ten Tusscher-Noble-Noble-Panfilov heterogeneous model for human ventricular myocytes. A four-state model of the sarcomeric control of contraction developed by Negroni and Lascano was employed to model the intracellular mechanism of force generation. The propagation of electrical excitation was described by a reaction-diffusion equation. The 3D geometrical model of the ventricle, based on single fiber contraction was used as a platform for the evaluation of proposed models. The model represents the myocardium as an anatomically oriented array of contracting fibers with individual fiber parameters such as size, spatial location, orientation and mechanical properties. Moreover, the contracting ventricle model interacts with intraventricular blood elements linking the contractile elements to the heart's preload and afterload, thereby producing the corresponding pressure-volume loop. The results show that the multiscale ventricle model is capable of simulating mechanical contraction, pressure generation and load interactions as well as demonstrating the individual contribution of each ion current.

  1. Contracts for field projects and supporting research on enhanced oil recovery. Progress review number 87

    SciTech Connect

    1997-10-01

    Approximately 30 research projects are summarized in this report. Title of the project, contract number, company or university, award amount, principal investigators, objectives, and summary of technical progress are given for each project. Enhanced oil recovery projects include chemical flooding, gas displacement, and thermal recovery. Most of the research projects though are related to geoscience technology and reservoir characterization.

  2. 48 CFR 5152.245-9001 - Government property for installation support services (cost-reimbursement contracts).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the provisions of FAR subpart 45.5 in effect on the date of this contract. (g) Maintenance. (1) Except... makes no warranty, express or implied, regarding the condition or fitness for use of any property. To... expense, either return such item or otherwise dispose of it or effect repairs or modifications. If...

  3. 48 CFR 5152.245-9001 - Government property for installation support services (cost-reimbursement contracts).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... make a decision as to disposition if agreement is reached with the Contractor that the property is no... normal parts replacement), and repair the property in accordance with sound industrial practice. (2) No... shall notify the Contracting Officer in writing when sound industrial practice requires maintenance in...

  4. 48 CFR 5152.245-9001 - Government property for installation support services (cost-reimbursement contracts).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... make a decision as to disposition if agreement is reached with the Contractor that the property is no... normal parts replacement), and repair the property in accordance with sound industrial practice. (2) No... shall notify the Contracting Officer in writing when sound industrial practice requires maintenance in...

  5. Navy Organic Airborne and Surface Influence Sweep Program Needs Defense Contract Management Agency Support

    DTIC Science & Technology

    2012-04-27

    Requirements International Organization for Standardization ISO 9001 :2008 – Quality Management . Also, the Program Manager worked with Naval Sea Systems...9 • FAR 52.246-11, Higher Level Contract Quality ,” which specifies high-level quality requirements for Quality Management Systems...states that the DCMA program integrator will base the technical assessment on engineering, software acquisition management , and manufacturing and quality

  6. Plans for Assessing Contractor Performance for the Camp Lemonnier Base Operations Support Contract Needed Improvement

    DTIC Science & Technology

    2015-08-27

    included in the contract. Those services include security operations, fire and emergency, supply, food, custodial, pest control, waste management, and...services to ensure facilities are clean, sanitary, and sightly. 14. Pest Control: Provide pest control services to ensure pests are controlled in a proper

  7. A continuum model for excitation-contraction of smooth muscle under finite deformations.

    PubMed

    Sharifimajd, Babak; Stålhand, Jonas

    2014-08-21

    The main focus in most of the continuum based muscle models is the mechanics of muscle contraction while other physiological processes governing muscle contraction, e.g., cell membrane excitation and activation, are ignored. These latter processes are essential to initiate contraction and to determine the amount of generated force, and by excluding them, the developed model cannot replicate the true behavior of the muscle in question. The aim of this study is to establish a thermodynamically and physiologically consistent framework which allows us to model smooth muscle contraction by including cell membrane excitability and kinetics of myosin phosphorylation, along with dynamics of smooth muscle contraction. The model accounts for these processes through a set of coupled dissipative constitutive equations derived by applying first principles. To show the performance of the derived model, it is evaluated for two different cases: a chemo-mechanical study of pig taenia coli cells where the excitation process is excluded, and an electro-chemo-mechanical study of rat myometrium. The results show that the model is able to replicate important aspects of the smooth muscle excitation-contraction process.

  8. A novel three-filament model of force generation in eccentric contraction of skeletal muscles.

    PubMed

    Schappacher-Tilp, Gudrun; Leonard, Timothy; Desch, Gertrud; Herzog, Walter

    2015-01-01

    We propose and examine a three filament model of skeletal muscle force generation, thereby extending classical cross-bridge models by involving titin-actin interaction upon active force production. In regions with optimal actin-myosin overlap, the model does not alter energy and force predictions of cross-bridge models for isometric contractions. However, in contrast to cross-bridge models, the three filament model accurately predicts history-dependent force generation in half sarcomeres for eccentric and concentric contractions, and predicts the activation-dependent forces for stretches beyond actin-myosin filament overlap.

  9. Federal Research and Development Contract Trends and the Supporting Industrial Base, 2000-2014

    DTIC Science & Technology

    2016-04-30

    stage, “seed corn” R&D has been relatively protected, cuts were not done within agencies on a “salami slice” basis, and large prime vendors have... relatively preserved, and the distribution of those cuts did not conform to expectations. Federal R&D Contracting in Context Four federal agencies...22%), Operational Systems Development (-12%), and GOCO (-16%) were all relatively preserved. Meanwhile, ATD (- 47%) and SD&D (-59%) both saw

  10. Defense Logistical Support Contracts in Iraq and Afghanistan: Issues for Congress

    DTIC Science & Technology

    2010-09-20

    in service contracting, long term sustainment strategies, information technology, and rapid acquisition;”15 and • The requirement for the Secretary...manage such complicated acquisition programs. Some Members of Congress may want DOD to develop a long - term plan to restore in-house expertise to make...government positions, and hiring an additional 10,000 defense acquisition workforce employees by 2015. According to DOD officials, the long - term

  11. Defense Logistical Support Contracts in Iraq and Afghanistan: Issues for Congress

    DTIC Science & Technology

    2010-04-28

    contracting, long term sustainment strategies, information technology, and rapid acquisition;”15 and • The requirement for the Secretary of...has the in-house expertise needed to manage such complicated acquisition programs. Some Members of Congress may want DOD to develop a long - term plan... long - term goal is to increase the size of the organic defense acquisition workforce to its 1998 levels of approximately 147,000 employees. At the

  12. Data Analysis and Modeling to Support NOWCAST and Forecast Activities at the Fallon Naval Air Station

    DTIC Science & Technology

    2016-06-07

    Data Analysis and Modeling to Support NOWCAST and Forecast Activities at the Fallon Naval Air Station Darko Koracin Desert Research Institute...kilometer horizontal resolution to support the NOWCAST system at the Fallon Naval Air Station (NAS); 2) To improve the accuracy of the forecasts...Analysis and Modeling to Support NOWCAST and Forecast Activities at the Fallon Naval Air Station 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM

  13. Mathematical Model Development and Simulation Support

    NASA Technical Reports Server (NTRS)

    Francis, Ronald C.; Tobbe, Patrick A.

    2000-01-01

    This report summarizes the work performed in support of the Contact Dynamics 6DOF Facility and the Flight Robotics Lab at NASA/ MSFC in the areas of Mathematical Model Development and Simulation Support.

  14. Standard Port-Visit Cost Forecasting Model for U.S. Navy Husbanding Contracts

    DTIC Science & Technology

    2009-12-01

    Husbanding Contracts By: Michael Alvin A. Marquez, Richard M. Rayos , and John I. Mercado December 2009 Advisors: Raymond...Forecasting Model for U.S. Navy Husbanding Contracts 6. AUTHOR(S) Michael Alvin A. Marquez, Richard M. Rayos , & John I. Mercado 5. FUNDING NUMBERS 7...Michael Alvin A. Marquez, Lieutenant Commander, United States Navy Richard M. Rayos , Lieutenant Commander, United States Navy John I. Mercado

  15. Filial Piety by Contract? The Emergence, Implementation, and Implications of the "Family Support Agreement" in China

    ERIC Educational Resources Information Center

    Chou, Rita Jing-Ann

    2011-01-01

    China has the largest aging population in the world today. Despite the Chinese tradition of filial piety, economic, social, cultural, and familial changes have made it increasingly difficult for older Chinese to receive support from adult children. To ensure parental support, the Family Support Agreement (FSA) emerged from a local community in the…

  16. Filial Piety by Contract? The Emergence, Implementation, and Implications of the "Family Support Agreement" in China

    ERIC Educational Resources Information Center

    Chou, Rita Jing-Ann

    2011-01-01

    China has the largest aging population in the world today. Despite the Chinese tradition of filial piety, economic, social, cultural, and familial changes have made it increasingly difficult for older Chinese to receive support from adult children. To ensure parental support, the Family Support Agreement (FSA) emerged from a local community in the…

  17. The Use of Decision Support Systems to Innovate the Process of Contracting for Goods and Services at the Marine Corps Eastern Recruiting Region Regional Contracting Office

    DTIC Science & Technology

    2001-12-01

    acquisition supervisor, it is publicized by the contract specialist by mailing, faxing, and e - mailing it to companies on the potential sources list. The...solicitation is then publicized by the contract specialist by mailing, faxing, and e - mailing it to companies on the potential sources list. The

  18. Individual Learner and Team Modeling for Adaptive Training and Education in Support of the US Army Learning Model: Research Outline

    DTIC Science & Technology

    2015-09-01

    Support of the US Army Learning Model: Research Outline by Greg Goodwin, Joan Johnston, Robert Sottilare, Keith Brawner, Anne Sinatra, and...Adaptive Training and Education in Support of the US Army Learning Model: Research Outline by Greg Goodwin, Joan Johnston, Robert Sottilare, Keith...Army Learning Model: Research Outline 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Greg Goodwin, Joan

  19. A Simulation Model for Setting Terms for Performance Based Contract Terms

    DTIC Science & Technology

    2010-05-01

    called performance-based life cycle product support) and the fictional superhero Batman. Like Batman, PBL has received a poor reputation because of...problem with a service constraint. Working Paper. University of Texas at Dallas, Richardson, TX. Fowler, A. (2009). Misunderstood superheroes ... Superheroes , Internet www.dau.mil/pubscats/PubsCats/atl/fow_jf09.pdf, Accessed on March 28, 2010. PBL is Not Contracting Out Logistics via Product Support

  20. Logistics Civil Augmentation Program Support Contract Needs to Comply With Acquisition Rules

    DTIC Science & Technology

    2011-01-07

    The LOGCAP DPD office in Kuwait assumed responsibility for assisting with developing more than $ 1 billion in annual requirements after the operations...The non- LOGCAP requirements were supported by 12 of 13 LOGCAP support contractor employees in the LOGCAP DPD office in Kuwait; only 1 LOGCAP...specialists, 3 cost analysts, and 1 administrative specialist. RICC personnel exercised Option Year 3 in February 2010, and definitized DPD support

  1. Analysis of Naval Facilities Engineering Command’s (NAVFAC) Contracting Processes Using the Contract Management Maturity Model (CMMM)

    DTIC Science & Technology

    2006-12-01

    influencing contract awards as part of the 2006 scandal involving Representative Randy ‘Duke’ Cunningham and defense contractor, Mitchell Wade. Also...Antecedents and Consequences of Failed Governance: the Enron Example. Corporate Governance, 5: 5. Garrett, G., & Rendon, R. 2005(a). Contract Management

  2. Chesapeake Bay mainstem monitoring program statistical and analytical support contract: final report, Volume 1

    SciTech Connect

    Not Available

    1987-09-01

    The primary focus of this contract was the development of a statistical analysis framework for detection of trends in Chesapeake Bay water quality attributable to pollution-control-management actions. The report found that, while there are aspects of the main Bay water-quality monitoring program that can be improved, the overall approach of the program is sound and will provide the empirical information needed to characterize and detect trends in Chesapeake Bay water quality and to evaluate the effectiveness of management actions. Continuation of this coordinated monitoring effort provides the best opportunity for generation of rigorous statements concerning the State-of-the-Bay and for the development of an ecologically sound water-quality management strategy.

  3. Chesapeake bay mainstem monitoring program statistical and analytical support contract: final report, volume 2

    SciTech Connect

    Not Available

    1987-09-01

    The primary focus of this contract was the development of a statistical analysis framework for detection of trends in Chesapeake Bay water quality attributable to pollution-control-management actions. The report found that, while there are aspects of the main Bay water-quality monitoring program that can be improved, the overall approach of the program is sound and will provide the empirical information needed to characterize and detect trends in Chesapeake Bay water quality and to evaluate the effectiveness of management actions. Continuation of this coordinated monitoring effort provides the best opportunity for generation of rigorous statements concerning the State-of-the-Bay and for the development of an ecologically sound water-quality management strategy.

  4. An ionic-chemical-mechanical model for muscle contraction.

    PubMed

    Manning, Gerald S

    2016-12-01

    The dynamic process underlying muscle contraction is the parallel sliding of thin actin filaments along an immobile thick myosin fiber powered by oar-like movements of protruding myosin cross bridges (myosin heads). The free energy for functioning of the myosin nanomotor comes from the hydrolysis of ATP bound to the myosin heads. The unit step of translational movement is based on a mechanical-chemical cycle involving ATP binding to myosin, hydrolysis of the bound ATP with ultimate release of the hydrolysis products, stress-generating conformational changes in the myosin cross bridge, and relief of built-up stress in the myosin power stroke. The cycle is regulated by a transition between weak and strong actin-myosin binding affinities. The dissociation of the weakly bound complex by addition of salt indicates the electrostatic basis for the weak affinity, while structural studies demonstrate that electrostatic interactions among negatively charged amino acid residues of actin and positively charged residues of myosin are involved in the strong binding interface. We therefore conjecture that intermediate states of increasing actin-myosin engagement during the weak-to-strong binding transition also involve electrostatic interactions. Methods of polymer solution physics have shown that the thin actin filament can be regarded in some of its aspects as a net negatively charged polyelectrolyte. Here we employ polyelectrolyte theory to suggest how actin-myosin electrostatic interactions might be of significance in the intermediate stages of binding, ensuring an engaged power stroke of the myosin motor that transmits force to the actin filament, and preventing the motor from getting stuck in a metastable pre-power stroke state. We provide electrostatic force estimates that are in the pN range known to operate in the cycle.

  5. The psychological contract: is the UK National Health Service a model employer?

    PubMed

    Fielden, Sandra; Whiting, Fiona

    2007-05-01

    The UK National Health Service (NHS) is facing recruitment challenges that mean it will need to become an 'employer of choice' if it is to continue to attract high-quality employees. This paper reports the findings from a study focusing on allied health professional staff (n = 67), aimed at establishing the expectations of the NHS inherent in their current psychological contract and to consider whether the government's drive to make the NHS a model employer meets those expectations. The findings show that the most important aspects of the psychological contract were relational and based on the investment made in the employment relationship by both parties. The employment relationship was one of high involvement but also one where transactional contract items, such as pay, were still of some importance. Although the degree of employee satisfaction with the relational content of the psychological contract was relatively positive, there was, nevertheless, a mismatch between levels of importance placed on such aspects of the contract and levels of satisfaction, with employees increasingly placing greater emphasis on those items the NHS is having the greatest difficulty providing. Despite this apparent disparity between employee expectation and the fulfilment of those expectations, the overall health of the psychological contract was still high.

  6. Modeling commodity salam contract between two parties for discrete and continuous time series

    NASA Astrophysics Data System (ADS)

    Hisham, Azie Farhani Badrol; Jaffar, Maheran Mohd

    2017-08-01

    In order for Islamic finance to remain competitive as the conventional, there needs a new development of Islamic compliance product such as Islamic derivative that can be used to manage the risk. However, under syariah principles and regulations, all financial instruments must not be conflicting with five syariah elements which are riba (interest paid), rishwah (corruption), gharar (uncertainty or unnecessary risk), maysir (speculation or gambling) and jahl (taking advantage of the counterparty's ignorance). This study has proposed a traditional Islamic contract namely salam that can be built as an Islamic derivative product. Although a lot of studies has been done on discussing and proposing the implementation of salam contract as the Islamic product however they are more into qualitative and law issues. Since there is lack of quantitative study of salam contract being developed, this study introduces mathematical models that can value the appropriate salam price for a commodity salam contract between two parties. In modeling the commodity salam contract, this study has modified the existing conventional derivative model and come out with some adjustments to comply with syariah rules and regulations. The cost of carry model has been chosen as the foundation to develop the commodity salam model between two parties for discrete and continuous time series. However, the conventional time value of money results from the concept of interest that is prohibited in Islam. Therefore, this study has adopted the idea of Islamic time value of money which is known as the positive time preference, in modeling the commodity salam contract between two parties for discrete and continuous time series.

  7. Non-invasive muscle contraction assay to study rodent models of sarcopenia

    PubMed Central

    2011-01-01

    Background Age-related sarcopenia is a disease state of loss of muscle mass and strength that affects physical function and mobility leading to falls, fractures, and disability. The need for therapies to treat age-related sarcopenia has attracted intensive preclinical research. To facilitate the discovery of these therapies, we have developed a non-invasive rat muscle functional assay system to efficiently measure muscle force and evaluate the efficacy of drug candidates. Methods The lower leg muscles of anesthetized rats are artificially stimulated with surface electrodes on the knee holders and the heel support, causing the lower leg muscles to push isometric pedals that are attached to force transducers. We developed a stimulation protocol to perform a fatigability test that reveals functional muscle parameters like maximal force, the rate of fatigue, fatigue-resistant force, as well as a fatigable muscle force index. The system is evaluated in a rat aging model and a rat glucocorticoid-induced muscle loss model Results The aged rats were generally weaker than adult rats and showed a greater reduction in their fatigable force when compared to their fatigue-resistant force. Glucocorticoid treated rats mostly lost fatigable force and fatigued at a higher rate, indicating reduced force from glycolytic fibers with reduced energy reserves. Conclusions The involuntary contraction assay is a reliable system to assess muscle function in rodents and can be applied in preclinical research, including age-related sarcopenia and other myopathy. PMID:22035016

  8. Simulating uterine contraction by using an electro-chemo-mechanical model.

    PubMed

    Sharifimajd, Babak; Thore, Carl-Johan; Stålhand, Jonas

    2016-06-01

    Contractions of uterine smooth muscle cells consist of a chain of physiological processes. These contractions provide the required force to expel the fetus from the uterus. The inclusion of these physiological processes is, therefore, imperative when studying uterine contractions. In this study, an electro-chemo-mechanical model to replicate the excitation, activation, and contraction of uterine smooth muscle cells is developed. The presented modeling strategy enables efficient integration of knowledge about physiological processes at the cellular level to the organ level. The model is implemented in a three-dimensional finite element setting to simulate uterus contraction during labor in response to electrical discharges generated by pacemaker cells and propagated within the myometrium via gap junctions. Important clinical factors, such as uterine electrical activity and intrauterine pressure, are predicted using this simulation. The predictions are in agreement with clinically measured data reported in the literature. A parameter study is also carried out to investigate the impact of physiologically related parameters on the uterine contractility.

  9. The deleterious consequences of privatization and outsourcing for hospital support work: the experiences of contracted-out hospital cleaners and dietary aids in Vancouver, Canada.

    PubMed

    Zuberi, Daniyal M; Ptashnick, Melita B

    2011-03-01

    This article is based on the findings of the Hospital Support Workers Study, which includes in-depth interviews with 70 hospital housekeepers and dietary aids in Vancouver, British Columbia, Canada. As a result of provincial government legislation in 2003, all hospital-based support work in the Vancouver region was privatized and contracted out to three multinational corporations. The outsourcing of hospital support services is part of a larger global trend toward neoliberal policy reform in health care. This article presents the perceptions of hospital support workers about the consequences of contracting out on their work conditions, training, turnover rates and other issues that directly affect their quality of work and have important implications for patient health and well-being. The findings suggest serious negative consequences for the health care system as a result of the privatization and contracting out of hospital support services. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Support of NASA quality requirements by defense contract administration services regions

    NASA Technical Reports Server (NTRS)

    Farrar, Hiram D.

    1966-01-01

    Defense Contract Administration Services Regions (DCASR) quality assurance personnel performing under NASA Letters of Delegation must work closely with the assigned technical representative of the NASA centers. It is realized that technical personnel from the NASA Centers cannot make on-site visits as frequently as they would like to. However, DCASR quality assurance personnel would know the assigned NASA technical representative and should contact him when problems arise. The technical representative is the expert on the hardware and should be consulted on any problem area. It is important that the DCASR quality assurance personnel recommend to the delegating NASA Center any new or improved methods of which they may be aware which would assist in achieving the desired quality and reliability in NASA hardware. NASA expects assignment of competent personnel in the Quality Assurance functional area and is not only buying the individual's technical skill, but also his experience. Suggestions by field personnel can many times up-grade the quality or the hardware.

  11. Support of NASA quality requirements by defense contract administration services regions

    NASA Technical Reports Server (NTRS)

    Farrar, Hiram D.

    1966-01-01

    Defense Contract Administration Services Regions (DCASR) quality assurance personnel performing under NASA Letters of Delegation must work closely with the assigned technical representative of the NASA centers. It is realized that technical personnel from the NASA Centers cannot make on-site visits as frequently as they would like to. However, DCASR quality assurance personnel would know the assigned NASA technical representative and should contact him when problems arise. The technical representative is the expert on the hardware and should be consulted on any problem area. It is important that the DCASR quality assurance personnel recommend to the delegating NASA Center any new or improved methods of which they may be aware which would assist in achieving the desired quality and reliability in NASA hardware. NASA expects assignment of competent personnel in the Quality Assurance functional area and is not only buying the individual's technical skill, but also his experience. Suggestions by field personnel can many times up-grade the quality or the hardware.

  12. Mitochondrial fusion is frequent in skeletal muscle and supports excitation–contraction coupling

    PubMed Central

    Eisner, Verónica; Lenaers, Guy

    2014-01-01

    Genetic targeting experiments indicate a fundamental role for mitochondrial fusion proteins in mammalian physiology. However, owing to the multiple functions of fusion proteins, their related phenotypes are not necessarily caused by altered mitochondrial fusion. Perhaps the biggest mystery is presented by skeletal muscle, where mostly globular-shaped mitochondria are densely packed into the narrow intermyofilamental space, limiting the interorganellar interactions. We show here that mitochondria form local networks and regularly undergo fusion events to share matrix content in skeletal muscle fibers. However, fusion events are less frequent and more stable in the fibers than in nondifferentiated myoblasts. Complementation among muscle mitochondria was suppressed by both in vivo genetic perturbations and chronic alcohol consumption that cause myopathy. An Mfn1-dependent pathway is revealed whereby fusion inhibition weakens the metabolic reserve of mitochondria to cause dysregulation of calcium oscillations during prolonged stimulation. Thus, fusion dynamically connects skeletal muscle mitochondria and its prolonged loss jeopardizes bioenergetics and excitation–contraction coupling, providing a potential pathomechanism contributing to myopathies. PMID:24751540

  13. Modeling Magnetomyograms of Uterine Contractions during Pregnancy Using a Multiscale Forward Electromagnetic Approach

    PubMed Central

    La Rosa, Patricio S.; Wilson, James D.; Eswaran, Hari; Nehorai, Arye

    2016-01-01

    Understanding the mechanisms of uterine contractions during pregnancy is especially important in predicting the onset of labor and thus in forecasting preterm deliveries. Preterm birth can cause serious health problems in newborns, as well as large financial burdens to society. Various techniques such as electromyography (EMG) and magnetomyography (MMG) have been developed to quantify uterine contractions. However, no widely accepted method to predict labor based on electromagnetic measurement is available. Therefore, developing a biophysical model of EMG and MMG could help better understand uterine contractions, interpret real measurements, and detect labor. In this work, we propose a multiscale realistic model of uterine contractions during pregnancy. At the cellular level, building on bifurcation theory, we apply generalized FitzHugh-Nagumo (FHN) equations that produces both plateau-type and bursting-type action potentials. At the tissue level, we introduce a random fiber orientation model applicable to an arbitrary uterine shape. We also develop an analytical expression for the propagation speed of transmembrane potential. At the organ level, a realistic volume conductor geometry model is provided based on magnetic resonance images of a pregnant woman. To simulate the measurements from the SQUID Array for Reproductive Assessment (SARA) device, we propose a sensor array model. Our model is able to reproduce the characteristics of action potentials. Additionally, we investigate the sensitivity of MMG to model configuration aspects such as volume geometry, fiber orientation, and pacemaker location. Our numerical results show that fiber orientation and pacemaker location are the key aspects that greatly affect the MMG as measured by the SARA device. We conclude that sphere is appropriate as an approximation of the volume geometry. The initial step towards validating the model against real MMG measurement is also presented. Our results show that the model is

  14. Modeling Magnetomyograms of Uterine Contractions during Pregnancy Using a Multiscale Forward Electromagnetic Approach.

    PubMed

    Zhang, Mengxue; Tidwell, Vanessa; La Rosa, Patricio S; Wilson, James D; Eswaran, Hari; Nehorai, Arye

    2016-01-01

    Understanding the mechanisms of uterine contractions during pregnancy is especially important in predicting the onset of labor and thus in forecasting preterm deliveries. Preterm birth can cause serious health problems in newborns, as well as large financial burdens to society. Various techniques such as electromyography (EMG) and magnetomyography (MMG) have been developed to quantify uterine contractions. However, no widely accepted method to predict labor based on electromagnetic measurement is available. Therefore, developing a biophysical model of EMG and MMG could help better understand uterine contractions, interpret real measurements, and detect labor. In this work, we propose a multiscale realistic model of uterine contractions during pregnancy. At the cellular level, building on bifurcation theory, we apply generalized FitzHugh-Nagumo (FHN) equations that produces both plateau-type and bursting-type action potentials. At the tissue level, we introduce a random fiber orientation model applicable to an arbitrary uterine shape. We also develop an analytical expression for the propagation speed of transmembrane potential. At the organ level, a realistic volume conductor geometry model is provided based on magnetic resonance images of a pregnant woman. To simulate the measurements from the SQUID Array for Reproductive Assessment (SARA) device, we propose a sensor array model. Our model is able to reproduce the characteristics of action potentials. Additionally, we investigate the sensitivity of MMG to model configuration aspects such as volume geometry, fiber orientation, and pacemaker location. Our numerical results show that fiber orientation and pacemaker location are the key aspects that greatly affect the MMG as measured by the SARA device. We conclude that sphere is appropriate as an approximation of the volume geometry. The initial step towards validating the model against real MMG measurement is also presented. Our results show that the model is

  15. Mechanisms test bed math model modification and simulation support

    NASA Technical Reports Server (NTRS)

    Gilchrist, Andrea C.; Tobbe, Patrick A.

    1995-01-01

    This report summarizes the work performed under contract NAS8-38771 in support of the Marshall Space Flight Center Six Degree of Freedom Motion Facility and Flight Robotics Laboratory. The contract activities included the development of the two flexible body and Remote Manipulator System simulations, Dynamic Overhead Target Simulator control system and operating software, Global Positioning System simulation, and Manipulator Coupled Spacecraft Controls Testbed. Technical support was also provided for the Lightning Imaging Sensor and Solar X-Ray Imaging programs. The cover sheets and introductory sections for the documentation written under this contract are provided as an appendix.

  16. Superficial aponeurosis of human gastrocnemius is elongated during contraction: implications for modeling muscle-tendon unit.

    PubMed

    Muramatsu, Tadashi; Muraoka, Tetsuro; Kawakami, Yasuo; Fukunaga, Tetsuo

    2002-02-01

    Two questions were addressed in this study: (1) how much strain of the superficial aponeurosis of the human medial gastrocnemius muscle (MG) was obtained during voluntary isometric contractions in vivo, (2) whether there existed inhomogeneity of the strain along the superficial aponeurosis. Seven male subjects, whose knees were extended and ankles were flexed at right angle, performed isometric plantar flexion while elongation of superficial aponeurosis of MG was determined from the movements of the intersections made by the superficial aponeurosis and fascicles using ultrasonography. The strain of the superficial aponeurosis at the maximum voluntary contraction, estimated from the elongation and length data, was 5.6+/-1.2%. There was no significant difference in strain between the proximal and distal parts of the superficial aponeurosis. Based on the present result and that of our previous study for the same subjects (J. Appl. Physiol 90 (2001) 1671), a model was formulated for a contracting uni-pennate muscle-tendon unit. This model, which could be applied to isometric contractions at other angles and therefore of wide use, showed that similar strain between superficial and deep aponeuroses of MG contributed to homogeneous fascicle length change within MG during contractions. These findings would contribute to clarifying the functions of the superficial aponeurosis and the effects of the superficial aponeurosis elongation on the whole muscle behavior.

  17. Quantitative model for predicting lymph formation and muscle compressibility in skeletal muscle during contraction and stretch

    PubMed Central

    Causey, Laura; Cowin, Stephen C.; Weinbaum, Sheldon

    2012-01-01

    Skeletal muscle is widely perceived as nearly incompressible despite the fact that blood and lymphatic vessels within the endomysial and perimysial spaces undergo significant changes in diameter and length during stretch and contraction. These fluid shifts between fascicle and interstitial compartments have proved extremely difficult to measure. In this paper, we propose a theoretical framework based on a space-filling hexagonal fascicle array to provide predictions of the displacement of blood and lymph into and out of the muscle’s endomysium and perimysium during stretch and contraction. We also use this model to quantify the distribution of blood and initial lymphatic (IL) vessels within a fascicle and its perimysial space using data for the rat spinotrapezius muscle. On average, there are 11 muscle fibers, 0.4 arteriole/venule pairs, and 0.2 IL vessels per fascicle. The model predicts that the blood volume in the endomysial space increases 24% and decreases 22% for a 20% contraction and stretch, respectively. However, these significant changes in blood volume in the endomysium produce a change of only ∼2% in fascicle cross-sectional area. In contrast, the entire muscle deviates from isovolumetry by 7% and 6% for a 20% contraction and stretch, respectively, largely attributable to the significantly larger blood volume changes that occur in the perimysial space. This suggests that arcade blood vessels in the perimysial space provide the primary pumping action required for the filling and emptying of ILs during muscular contraction and stretch. PMID:22615376

  18. Mathematical Modeling Of Life-Support Systems

    NASA Technical Reports Server (NTRS)

    Seshan, Panchalam K.; Ganapathi, Balasubramanian; Jan, Darrell L.; Ferrall, Joseph F.; Rohatgi, Naresh K.

    1994-01-01

    Generic hierarchical model of life-support system developed to facilitate comparisons of options in design of system. Model represents combinations of interdependent subsystems supporting microbes, plants, fish, and land animals (including humans). Generic model enables rapid configuration of variety of specific life support component models for tradeoff studies culminating in single system design. Enables rapid evaluation of effects of substituting alternate technologies and even entire groups of technologies and subsystems. Used to synthesize and analyze life-support systems ranging from relatively simple, nonregenerative units like aquariums to complex closed-loop systems aboard submarines or spacecraft. Model, called Generic Modular Flow Schematic (GMFS), coded in such chemical-process-simulation languages as Aspen Plus and expressed as three-dimensional spreadsheet.

  19. Mathematical Modeling Of Life-Support Systems

    NASA Technical Reports Server (NTRS)

    Seshan, Panchalam K.; Ganapathi, Balasubramanian; Jan, Darrell L.; Ferrall, Joseph F.; Rohatgi, Naresh K.

    1994-01-01

    Generic hierarchical model of life-support system developed to facilitate comparisons of options in design of system. Model represents combinations of interdependent subsystems supporting microbes, plants, fish, and land animals (including humans). Generic model enables rapid configuration of variety of specific life support component models for tradeoff studies culminating in single system design. Enables rapid evaluation of effects of substituting alternate technologies and even entire groups of technologies and subsystems. Used to synthesize and analyze life-support systems ranging from relatively simple, nonregenerative units like aquariums to complex closed-loop systems aboard submarines or spacecraft. Model, called Generic Modular Flow Schematic (GMFS), coded in such chemical-process-simulation languages as Aspen Plus and expressed as three-dimensional spreadsheet.

  20. The Generalized Hill Model: A Kinematic Approach Towards Active Muscle Contraction.

    PubMed

    Göktepe, Serdar; Menzel, Andreas; Kuhl, Ellen

    2014-12-01

    Excitation-contraction coupling is the physiological process of converting an electrical stimulus into a mechanical response. In muscle, the electrical stimulus is an action potential and the mechanical response is active contraction. The classical Hill model characterizes muscle contraction though one contractile element, activated by electrical excitation, and two non-linear springs, one in series and one in parallel. This rheology translates into an additive decomposition of the total stress into a passive and an active part. Here we supplement this additive decomposition of the stress by a multiplicative decomposition of the deformation gradient into a passive and an active part. We generalize the one-dimensional Hill model to the three-dimensional setting and constitutively define the passive stress as a function of the total deformation gradient and the active stress as a function of both the total deformation gradient and its active part. We show that this novel approach combines the features of both the classical stress-based Hill model and the recent active-strain models. While the notion of active stress is rather phenomenological in nature, active strain is micro-structurally motivated, physically measurable, and straightforward to calibrate. We demonstrate that our model is capable of simulating excitation-contraction coupling in cardiac muscle with its characteristic features of wall thickening, apical lift, and ventricular torsion.

  1. The generalized Hill model: A kinematic approach towards active muscle contraction

    NASA Astrophysics Data System (ADS)

    Göktepe, Serdar; Menzel, Andreas; Kuhl, Ellen

    2014-12-01

    Excitation-contraction coupling is the physiological process of converting an electrical stimulus into a mechanical response. In muscle, the electrical stimulus is an action potential and the mechanical response is active contraction. The classical Hill model characterizes muscle contraction though one contractile element, activated by electrical excitation, and two non-linear springs, one in series and one in parallel. This rheology translates into an additive decomposition of the total stress into a passive and an active part. Here we supplement this additive decomposition of the stress by a multiplicative decomposition of the deformation gradient into a passive and an active part. We generalize the one-dimensional Hill model to the three-dimensional setting and constitutively define the passive stress as a function of the total deformation gradient and the active stress as a function of both the total deformation gradient and its active part. We show that this novel approach combines the features of both the classical stress-based Hill model and the recent active-strain models. While the notion of active stress is rather phenomenological in nature, active strain is micro-structurally motivated, physically measurable, and straightforward to calibrate. We demonstrate that our model is capable of simulating excitation-contraction coupling in cardiac muscle with its characteristic features of wall thickening, apical lift, and ventricular torsion.

  2. The Generalized Hill Model: A Kinematic Approach Towards Active Muscle Contraction

    PubMed Central

    Menzel, Andreas; Kuhl, Ellen

    2014-01-01

    Excitation-contraction coupling is the physiological process of converting an electrical stimulus into a mechanical response. In muscle, the electrical stimulus is an action potential and the mechanical response is active contraction. The classical Hill model characterizes muscle contraction though one contractile element, activated by electrical excitation, and two non-linear springs, one in series and one in parallel. This rheology translates into an additive decomposition of the total stress into a passive and an active part. Here we supplement this additive decomposition of the stress by a multiplicative decomposition of the deformation gradient into a passive and an active part. We generalize the one-dimensional Hill model to the three-dimensional setting and constitutively define the passive stress as a function of the total deformation gradient and the active stress as a function of both the total deformation gradient and its active part. We show that this novel approach combines the features of both the classical stress-based Hill model and the recent active-strain models. While the notion of active stress is rather phenomenological in nature, active strain is micro-structurally motivated, physically measurable, and straightforward to calibrate. We demonstrate that our model is capable of simulating excitation-contraction coupling in cardiac muscle with its characteristic features of wall thickening, apical lift, and ventricular torsion. PMID:25221354

  3. Modeling force-velocity relation in skeletal muscle isotonic contraction using an artificial neural network.

    PubMed

    Dariani, Sharareh; Keshavarz, Mansoor; Parviz, Mohsen; Raoufy, Mohammad Reza; Gharibzadeh, Shahriar

    2007-01-01

    The aim of this study is to design an artificial neural network (ANN) to model force-velocity relation in skeletal muscle isotonic contraction. We obtained the data set, including physiological and morphometric parameters, by myography and morphometric measurements on frog gastrocnemius muscle. Then, we designed a multilayer perceptron ANN, the inputs of which are muscle volume, muscle optimum length, tendon length, preload, and afterload. The output of the ANN is contraction velocity. The experimental data were divided randomly into two parts. The first part was used to train the ANN. In order to validate the model, the second part of experimental data, which was not used in training, was employed to the ANN and then, its output was compared with Hill model and the experimental data. The behavior of ANN in high forces was more similar to experimental data, but in low forces the Hill model had better results. Furthermore, extrapolation of ANN performance showed that our model is more or less able to simulate eccentric contraction. Our results indicate that ANNs represent a powerful tool to capture some essential features of muscle isotonic contraction.

  4. Classroom Crisis Intervention through Contracting: A Moral Development Model.

    ERIC Educational Resources Information Center

    Smaby, Marlowe H.; Tamminen, Armas W.

    1981-01-01

    A counselor can arbitrate problem situations using a systematic approach to classroom intervention which includes meetings with the teacher and students. This crisis intervention model based on moral development can be more effective than reliance on guidance activities disconnected from the actual classroom settings where the problems arise.…

  5. The Comprehensive Female Soldier Support Model.

    PubMed

    Roberts, Daniel L; Kovacich, Joann; Rivers, Melvin J

    2017-04-25

    Women represent a small minority in the U.S. military and an even smaller minority in the military chaplaincy. Prior to this study, the U.S. Army chaplaincy did not have a gender-specific model for providing support to women soldiers. In this Delphi research project, wounded women soldiers and female military chaplains provided expert opinions to develop the comprehensive female soldier support model (CFS2). Ten military women and 11 female chaplains who had been deployed overseas contributed to the body of knowledge related to the understanding of the emotional and spiritual support needs of wounded female soldiers. Five key findings appeared in the study: (a) many women did not get the chaplain support they needed; (b) the gender of the chaplain was not significant; (c) the attitude of the chaplain was critical; (d) chaplain skills not found in literature were identified; and (e) the comprehensive female soldier support model was developed.

  6. The Entrepreneurial Model of Supported Employment.

    ERIC Educational Resources Information Center

    Markve, Robert; And Others

    1992-01-01

    Existing models of supported employment (individual placement, mobile crew, enclave, and benchwork models) have limited utility in rural areas. The Black Hills Special Services Cooperative (Sturgis, South Dakota) developed an entrepreneurial model that addresses the lack of rural employers and transportation problems by creating new businesses…

  7. Modeling Ca2+-Bound Troponin in Excitation Contraction Coupling

    PubMed Central

    Zot, Henry G.; Hasbun, Javier E.

    2016-01-01

    To explain disparate decay rates of cytosolic Ca2+ and structural changes in the thin filaments during a twitch, we model the time course of Ca2+-bound troponin (Tn) resulting from the free Ca2+ transient of fast skeletal muscle. In fibers stretched beyond overlap, the decay of Ca2+ as measured by a change in fluo-3 fluorescence is significantly slower than the intensity decay of the meridional 1/38.5 nm−1 reflection of Tn; this is not simply explained by considering only the Ca2+ binding properties of Tn alone (Matsuo et al., 2010). We apply a comprehensive model that includes the known Ca2+ binding properties of Tn in the context of the thin filament with and without cycling crossbridges. Calculations based on the model predict that the transient of Ca2+-bound Tn correlates with either the fluo-3 time course in muscle with overlapping thin and thick filaments or the intensity of the meridional 1/38.5 nm−1 reflection in overstretched muscle. Hence, cycling crossbridges delay the dissociation of Ca2+ from Tn. Correlation with the fluo-3 fluorescence change is not causal given that the transient of Ca2+-bound Tn depends on sarcomere length, whereas the fluo-3 fluorescence change does not. Transient positions of tropomyosin calculated from the time course of Ca2+-bound Tn are in reasonable agreement with the transient of measured perturbations of the Tn repeat in overlap and non-overlap muscle preparations. PMID:27708586

  8. Modeling Ca(2+)-Bound Troponin in Excitation Contraction Coupling.

    PubMed

    Zot, Henry G; Hasbun, Javier E

    2016-01-01

    To explain disparate decay rates of cytosolic Ca(2+) and structural changes in the thin filaments during a twitch, we model the time course of Ca(2+)-bound troponin (Tn) resulting from the free Ca(2+) transient of fast skeletal muscle. In fibers stretched beyond overlap, the decay of Ca(2+) as measured by a change in fluo-3 fluorescence is significantly slower than the intensity decay of the meridional 1/38.5 nm(-1) reflection of Tn; this is not simply explained by considering only the Ca(2+) binding properties of Tn alone (Matsuo et al., 2010). We apply a comprehensive model that includes the known Ca(2+) binding properties of Tn in the context of the thin filament with and without cycling crossbridges. Calculations based on the model predict that the transient of Ca(2+)-bound Tn correlates with either the fluo-3 time course in muscle with overlapping thin and thick filaments or the intensity of the meridional 1/38.5 nm(-1) reflection in overstretched muscle. Hence, cycling crossbridges delay the dissociation of Ca(2+) from Tn. Correlation with the fluo-3 fluorescence change is not causal given that the transient of Ca(2+)-bound Tn depends on sarcomere length, whereas the fluo-3 fluorescence change does not. Transient positions of tropomyosin calculated from the time course of Ca(2+)-bound Tn are in reasonable agreement with the transient of measured perturbations of the Tn repeat in overlap and non-overlap muscle preparations.

  9. SCOOP - A Contract-Based Concurrent Object-Oriented Programming Model

    NASA Astrophysics Data System (ADS)

    Morandi, Benjamin; Bauer, Sebastian S.; Meyer, Bertrand

    SCOOP is a concurrent object-oriented programming model based on contracts. The model introduces processors as a new concept and it generalizes existing object-oriented concepts for the concurrent context. Simplicity is the main objective of SCOOP. The model guarantees the absence of data races in any execution of a SCOOP program. This article is a technical description of SCOOP as defined by Nienaltowski [11] and Meyer [7,9,10].

  10. Promises from Afar: A Model of International Student Psychological Contract in Business Education

    ERIC Educational Resources Information Center

    Bordia, Sarbari; Bordia, Prashant; Restubog, Simon Lloyd D.

    2015-01-01

    Despite their significant presence in western business schools, the needs and experiences of international students have not been adequately reflected in the business education literature. We draw upon psychological contract theory--used to understand employer-employee relationships--to develop a novel theoretical model on the international…

  11. Model for PCP contracts offers right incentives for Medicare, Medicaid providers.

    PubMed

    1999-10-01

    Consider this model for PCP contracting. Provider organizations in Medicare and Medicaid often structure arrangements with their primary care providers that set up the organizations--and the doctors--to fail. An actuary from Milliman & Robertson in Seattle illustrates how to establish the right kinds of incentives for PCPs.

  12. Promises from Afar: A Model of International Student Psychological Contract in Business Education

    ERIC Educational Resources Information Center

    Bordia, Sarbari; Bordia, Prashant; Restubog, Simon Lloyd D.

    2015-01-01

    Despite their significant presence in western business schools, the needs and experiences of international students have not been adequately reflected in the business education literature. We draw upon psychological contract theory--used to understand employer-employee relationships--to develop a novel theoretical model on the international…

  13. A model of muscle contraction based on the Langevin equation with actomyosin potentials.

    PubMed

    Tamura, Youjiro; Ito, Akira; Saito, Masami

    2017-02-01

    We propose a muscle contraction model that is essentially a model of the motion of myosin motors as described by a Langevin equation. This model involves one-dimensional numerical calculations wherein the total force is the sum of a viscous force proportional to the myosin head velocity, a white Gaussian noise produced by random forces and other potential forces originating from the actomyosin structure and intra-molecular charges. We calculate the velocity of a single myosin on an actin filament to be 4.9-49 μm/s, depending on the viscosity between the actomyosin molecules. A myosin filament with a hundred myosin heads is used to simulate the contractions of a half-sarcomere within the skeletal muscle. The force response due to a quick release in the isometric contraction is simulated using a process wherein crossbridges are changed forcibly from one state to another. In contrast, the force response to a quick stretch is simulated using purely mechanical characteristics. We simulate the force-velocity relation and energy efficiency in the isotonic contraction and adenosine triphosphate consumption. The simulation results are in good agreement with the experimental results. We show that the Langevin equation for the actomyosin potentials can be modified statistically to become an existing muscle model that uses Maxwell elements.

  14. Another Look at Helmholtz's Model for the Gravitational Contraction of the Sun

    ERIC Educational Resources Information Center

    Tort, A. C.; Nogarol, F.

    2011-01-01

    We take another look at the Helmholtz model for the gravitational contraction of the Sun. We show that there are two other pedagogically useful ways of rederiving Helmholtz's main results that make use of Gauss's law, the concept of gravitational field energy and the work-kinetic energy theorem. An account of the energy balance involved in the…

  15. Another Look at Helmholtz's Model for the Gravitational Contraction of the Sun

    ERIC Educational Resources Information Center

    Tort, A. C.; Nogarol, F.

    2011-01-01

    We take another look at the Helmholtz model for the gravitational contraction of the Sun. We show that there are two other pedagogically useful ways of rederiving Helmholtz's main results that make use of Gauss's law, the concept of gravitational field energy and the work-kinetic energy theorem. An account of the energy balance involved in the…

  16. Better Cost-Control Measures Are Needed on the Army’s Cost-Reimbursable Services Contract for Logistics Support of Stryker Vehicles

    DTIC Science & Technology

    2012-06-18

    Report No. DODIG-2012-102 June 18, 2012 Better Cost-Control Measures Are Needed on the Army’s Cost-Reimbursable Services...Better Cost-Control Measures Are Needed on the Army’s Cost-Reimbursable Services Contract for Logistics Support of Stryker Vehicles 5a. CONTRACT NUMBER...ACQUISITION, TECHNOLOGY, AND LOGISTICS AUDITOR GENERAL DEPARTMENT OF THE ARMY SUBJECT: Better Cost-Control Measures Are Needed on the Army’s Cost

  17. [A simple kinetic model of myocardium contraction: calcium-mechanics coupling].

    PubMed

    Semin, F A

    2014-01-01

    A kinetic model of cardiac muscle contraction is suggested. It is based on our earlier simplified model of the kinetics of the actin-myosin interaction. We examined the kinetics of formation of calcium-troponin complexes that open the binding sites-on actin for myosin heads. The model also takes into account the cooperativity of this process and the influence of myosin heads on it. It was shown that with proper choice of its parameters the model appropriately describes the dependence of myocardium activation.on sarcomeres length that underlies the Frank-Starling law of the heart. The model fits both steady state experiments on myocardial specimens with permeable membrane and twitch contractions of intact cardiac muscle. It also describes well the myocardium load-dependent relaxation.

  18. Analysis of Commercial Contract Training for the Marine Corps (Phase II) [And] Commercial Contract Training Marine Corps Area VOTEC Support Center (AVSC) Guidelines. Final Report.

    ERIC Educational Resources Information Center

    Copeland, D. Robert; And Others

    The two-part report describing the Phase 2 findings of a two-phase study demonstrates the utility of the commercial contract training concept for satisfying certain Marine Corps skill training requirements. Part 1 concerns source evaluation, skill analysis and selection, contractual considerations, and comparative training capability evaluation.…

  19. Analysis of Commercial Contract Training for the Navy (Phase II) [And] Commercial Contract Training Navy Area VOTEC Support Center (AVSC) Guidelines. Final Report.

    ERIC Educational Resources Information Center

    Copeland, D. Robert; And Others

    The two-part report describing the Phase 2 findings of a two-phase study demonstrates the utility of the commercial contract training concept for satisfying certain Navy skill training requirements. Part 1 concerns source evaluation, skill analysis and selection, contractual considerations, and comparative training capability evaluation. It…

  20. Maintenance service contract model for heavy equipment in mining industry using principal agent theory

    NASA Astrophysics Data System (ADS)

    Pakpahan, Eka K. A.; Iskandar, Bermawi P.

    2015-12-01

    Mining industry is characterized by a high operational revenue, and hence high availability of heavy equipment used in mining industry is a critical factor to ensure the revenue target. To maintain high avaliability of the heavy equipment, the equipment's owner hires an agent to perform maintenance action. Contract is then used to control the relationship between the two parties involved. The traditional contracts such as fixed price, cost plus or penalty based contract studied is unable to push agent's performance to exceed target, and this in turn would lead to a sub-optimal result (revenue). This research deals with designing maintenance contract compensation schemes. The scheme should induce agent to select the highest possible maintenance effort level, thereby pushing agent's performance and achieve maximum utility for both parties involved. Principal agent theory is used as a modeling approach due to its ability to simultaneously modeled owner and agent decision making process. Compensation schemes considered in this research includes fixed price, cost sharing and revenue sharing. The optimal decision is obtained using a numerical method. The results show that if both parties are risk neutral, then there are infinite combination of fixed price, cost sharing and revenue sharing produced the same optimal solution. The combination of fixed price and cost sharing contract results in the optimal solution when the agent is risk averse, while the optimal combination of fixed price and revenue sharing contract is obtained when agent is risk averse. When both parties are risk averse, the optimal compensation scheme is a combination of fixed price, cost sharing and revenue sharing.

  1. A 3D skeletal muscle model coupled with active contraction of muscle fibres and hyperelastic behaviour.

    PubMed

    Tang, C Y; Zhang, G; Tsui, C P

    2009-05-11

    This paper presents a three-dimensional finite element model of skeletal muscle which was developed to simulate active and passive non-linear mechanical behaviours of the muscle during lengthening or shortening under either quasi-static or dynamic condition. Constitutive relation of the muscle was determined by using a strain energy approach, while active contraction behaviour of the muscle fibre was simulated by establishing a numerical algorithm based on the concept of the Hill's three-element muscle model. The proposed numerical algorithm could be used to predict concentric, eccentric, isometric and isotonic contraction behaviours of the muscle. The proposed numerical algorithm and constitutive model for the muscle were derived and implemented into a non-linear large deformation finite element programme ABAQUS by using user-defined material subroutines. A number of scenarios have been used to demonstrate capability of the model for simulating both quasi-static and dynamic response of the muscle. Validation of the proposed model has been performed by comparing the simulated results with the experimental ones of frog gastrocenemius muscle deformation. The effects of the fusiform muscle geometry and fibre orientation on the stress and fibre stretch distributions of frog muscle during isotonic contraction have also been investigated by using the proposed model. The predictability of the present model for dynamic response of the muscle has been demonstrated by simulating the extension of a squid tentacle during a strike to catch prey.

  2. EOSDIS and Support for Earth Science Modeling

    NASA Astrophysics Data System (ADS)

    Behnke, J.; Lu, Y.; Boquist, C. L.

    2005-12-01

    The Earth Observation System Data and Information System (EOSDIS) is a large, complex data system currently supporting over 18 operational NASA satellite missions including the flagship EOS missions: Terra, Aqua, and Aura. The observations collected by these missions are kept at geographically distributed data centers. An important effort for these data centers is feeding data to the science modeling communities and together feeding decision support systems. The EOSDIS project provides several infrastructure components to facilitate the use of data in models. This includes methods for aggregate data ordering, support for standardization of data structures and systems, interdisciplinary science support, and other user services. At this time, there is a rudimentary framework in place for facilitating support for multi-disciplinary global modeling. While there has been much progress in getting data from missions into models, there is room for improvement and challenges to overcome. Topics of this paper include the key areas where modelers' have problems utilizing EOS datasets and effective ways for the modelling community to influence data center services and science data products.

  3. Simulation of the contraction of the ventricles in a human heart model including atria and pericardium.

    PubMed

    Fritz, Thomas; Wieners, Christian; Seemann, Gunnar; Steen, Henning; Dössel, Olaf

    2014-06-01

    During the contraction of the ventricles, the ventricles interact with the atria as well as with the pericardium and the surrounding tissue in which the heart is embedded. The atria are stretched, and the atrioventricular plane moves toward the apex. The atrioventricular plane displacement (AVPD) is considered to be a major contributor to the ventricular function, and a reduced AVPD is strongly related to heart failure. At the same time, the epicardium slides almost frictionlessly on the pericardium with permanent contact. Although the interaction between the ventricles, the atria and the pericardium plays an important role for the deformation of the heart, this aspect is usually not considered in computational models. In this work, we present an electromechanical model of the heart, which takes into account the interaction between ventricles, pericardium and atria and allows to reproduce the AVPD. To solve the contact problem of epicardium and pericardium, a contact handling algorithm based on penalty formulation was developed, which ensures frictionless and permanent contact. Two simulations of the ventricular contraction were conducted, one with contact handling of pericardium and heart and one without. In the simulation with contact handling, the atria were stretched during the contraction of the ventricles, while, due to the permanent contact with the pericardium, their volume increased. In contrast to that, in the simulations without pericardium, the atria were also stretched, but the change in the atrial volume was much smaller. Furthermore, the pericardium reduced the radial contraction of the ventricles and at the same time increased the AVPD.

  4. New contractivity condition in a population model with piecewise constant arguments

    NASA Astrophysics Data System (ADS)

    Muroya, Yoshiaki

    2008-10-01

    In this paper, we improve contractivity conditions of solutions for the positive equilibrium of the following differential equation with piecewise constant arguments: where r(t) is a nonnegative continuous function on [0,+[infinity]), r(t)[not identical with]0, , bi[greater-or-equal, slanted]0, i=0,1,2,...,m, and . In particular, for the case a=0 and m[greater-or-equal, slanted]1, we really improve the known three type conditions of the contractivity for solutions of this model (see for example, [Y. Muroya, A sufficient condition on global stability in a logistic equation with piecewise constant arguments, Hokkaido Math. J. 32 (2003) 75-83]). For the other case a[not equal to]0 and m[greater-or-equal, slanted]1, under the condition , the obtained result partially improves the known results on the contractivity of solutions for the positive equilibrium of this model given by the author [Y. Muroya, Persistence, contractivity and global stability in logistic equations with piecewise constant delays, J. Math. Anal. Appl. 270 (2002) 602-635] and others.

  5. Contraction behaviors of Vorticella sp. stalk investigated using high-speed video camera. I: Nucleation and growth model

    PubMed Central

    Kamiguri, Junko; Tsuchiya, Noriko; Hidema, Ruri; Tachibana, Masatoshi; Yatabe, Zenji; Shoji, Masahiko; Hashimoto, Chihiro; Pansu, Robert Bernard; Ushiki, Hideharu

    2012-01-01

    The contraction process of living Vorticella sp. has been investigated by image processing using a high-speed video camera. In order to express the temporal change in the stalk length resulting from the contraction, a damped spring model and a nucleation and growth model are applied. A double exponential is deduced from a conventional damped spring model, while a stretched exponential is newly proposed from a nucleation and growth model. The stretched exponential function is more suitable for the curve fitting and suggests a more particular contraction mechanism in which the contraction of the stalk begins near the cell body and spreads downwards along the stalk. The index value of the stretched exponential is evaluated in the range from 1 to 2 in accordance with the model in which the contraction undergoes through nucleation and growth in a one-dimensional space. PMID:27857602

  6. Contraction behaviors of Vorticella sp. stalk investigated using high-speed video camera. I: Nucleation and growth model.

    PubMed

    Kamiguri, Junko; Tsuchiya, Noriko; Hidema, Ruri; Tachibana, Masatoshi; Yatabe, Zenji; Shoji, Masahiko; Hashimoto, Chihiro; Pansu, Robert Bernard; Ushiki, Hideharu

    2012-01-01

    The contraction process of living Vorticella sp. has been investigated by image processing using a high-speed video camera. In order to express the temporal change in the stalk length resulting from the contraction, a damped spring model and a nucleation and growth model are applied. A double exponential is deduced from a conventional damped spring model, while a stretched exponential is newly proposed from a nucleation and growth model. The stretched exponential function is more suitable for the curve fitting and suggests a more particular contraction mechanism in which the contraction of the stalk begins near the cell body and spreads downwards along the stalk. The index value of the stretched exponential is evaluated in the range from 1 to 2 in accordance with the model in which the contraction undergoes through nucleation and growth in a one-dimensional space.

  7. A mathematical model of the coupled mechanisms of cell adhesion, contraction and spreading.

    PubMed

    Vernerey, Franck J; Farsad, Mehdi

    2014-03-01

    Recent research has shown that cell spreading is highly dependent on the contractility of its cytoskeleton and the mechanical properties of the environment it is located in. The dynamics of such process is critical for the development of tissue engineering strategy but is also a key player in wound contraction, tissue maintenance and angiogenesis. To better understand the underlying physics of such phenomena, the paper describes a mathematical formulation of cell spreading and contraction that couples the processes of stress fiber formation, protrusion growth through actin polymerization at the cell edge and dynamics of cross-membrane protein (integrins) enabling cell-substrate attachment. The evolving cell's cytoskeleton is modeled as a mixture of fluid, proteins and filaments that can exchange mass and generate contraction. In particular, besides self-assembling into stress fibers, actin monomers able to polymerize into an actin meshwork at the cell's boundary in order to push the membrane forward and generate protrusion. These processes are possible via the development of cell-substrate attachment complexes that arise from the mechano-sensitive equilibrium of membrane proteins, known as integrins. After deriving the governing equation driving the dynamics of cell evolution and spreading, we introduce a numerical solution based on the extended finite element method, combined with a level set formulation. Numerical simulations show that the proposed model is able to capture the dependency of cell spreading and contraction on substrate stiffness and chemistry. The very good agreement between model predictions and experimental observations suggests that mechanics plays a strong role into the coupled mechanisms of contraction, adhesion and spreading of adherent cells.

  8. A mathematical model of the coupled mechanisms of cell adhesion, contraction and spreading

    PubMed Central

    Vernerey, Franck J.; Farsad, Mehdi

    2013-01-01

    Recent research has shown that cell spreading is highly dependent on the contractililty of its cytoskeleton and the mechanical properties of the environment it is located in. The dynamics of such process is critical for the development of tissue engineering strategy but is also a key player in wound contraction, tissue maintenance and angiogenesis. To better understand the underlying physics of such phenomena, the paper describes a mathematical formulation of cell spreading and contraction that couples the processes of stress fiber formation, protrusion growth through actin polymerization at the cell edge and dynamics of cross-membrane protein (integrins) enabling cell-substrate attachment. The evolving cell’s cytoskeleton is modeled as a mixture of fluid, proteins and filaments that can exchange mass and generate contraction. In particular, besides self-assembling into stress fibers, actin monomers able to polymerize into an actin meshwork at the cell’s boundary in order to push the membrane forward and generate protrusion. These processes are possible via the development of cell-substrate attachment complexes that arise from the mechano-sensitive equilibrium of membrane proteins, known as integrins. After deriving the governing equation driving the dynamics of cell evolution and spreading, we introduce a numerical solution based on the extended finite element method, combined with a level set formulation. Numerical simulations show that the proposed model is able to capture the dependency of cell spreading and contraction on substrate stiffness and chemistry. The very good agreement between model predictions and experimental observations suggests that mechanics plays a strong role into the coupled mechanisms of contraction, adhesion and spreading of adherent cells. PMID:23463540

  9. A comprehensive mathematical framework for modeling intestinal smooth muscle cell contraction with applications to intestinal edema.

    PubMed

    Young, Jennifer; Ozisik, Sevtap; Riviere, Beatrice; Shamim, Muhammad

    2015-04-01

    The contraction of intestinal smooth muscle cells (ISMCs) involves many coordinated biochemical and mechanical processes. In this work, we present a framework for modeling ISMC contractility that begins with chemical models of calcium dynamics, continues with myosin light chain phosphorylation and force generation, and ends with a cell model of the ISMC undergoing contraction-relaxation. The motivation for developing this comprehensive framework is to study the effects of edema (excess fluid build-up in the muscle tissue) on ISMC contractility. The hypothesis is that more fluid equates to dilution of an external stimulis, eventually leading to reduced contractility. We compare our results to experimental data collected from normal versus edematous intestinal muscle tissue.

  10. Examination of Ventricular Contraction Function Using Electrical Lumped Circuit Model of Circulation System

    NASA Astrophysics Data System (ADS)

    Ito, Mitsuyo; Koya, Yoshiharu; Mizoshiri, Isao

    Presently, many of the already proposed blood circulation models are mainly partial models although they are precise models. A complete model that is a combination of these partial models are difficult to analyze because it is complicated to consider both the viscosity of blood and circulatory details at the same time. So, it is difficult to control the model parameters in order to adapt to various cases of circulatory diseases. This paper proposes a complete circulation model as a lumped electrical circuit, which is comparatively simple. In the circuit model, total blood is modeled as seven lumped capacitors, representing the functions of atriums, ventricles, arteries, veins and lungs. We regard the variation of the ventricle capacitance as the driving force of the complete circulation model. In our model, we considered only the variation of pressure between each part and the blood capacity of each part. In particular, the contraction function of the left ventricle is examined under the consideration of whole blood circulation.

  11. DTI data modeling for unlimited query support

    NASA Astrophysics Data System (ADS)

    Siadat, Mohammad-Reza; Hammad, Rafat; Shetty, Anil; Soltanian-Zadeh, Hamid; Sethi, Ishwar K.; Eetemadi, Ameen; Elisevich, Kost V.

    2009-02-01

    This paper describes Data Modeling for unstructured data of Diffusion Tensor Imaging (DTI). Data Modeling is an essential first step for data preparation in any data management and data mining procedure. Conventional Entity- Relational (E-R) data modeling is lossy, irreproducible, and time-consuming especially when dealing with unstructured image data associated with complex systems like the human brain. We propose a methodological framework for more objective E-R data modeling with unlimited query support by eliminating the structured content-dependent metadata associated with the unstructured data. The proposed method is applied to DTI data and a minimum system is implemented accordingly. Eventually supported with navigation, data fusion, and feature extraction modules, the proposed system provides a content-based support environment (C-BASE). Such an environment facilitates an unlimited query support with a reproducible and efficient database schema. Switching between different modalities of data, while confining the feature extractors within the object(s) of interest, we supply anatomically specific query results. The price of such a scheme is relatively large storage and in some cases high computational cost. The data modeling and its mathematical framework, behind the scene of query executions and the user interface of the system are presented in this paper.

  12. 7 CFR Appendix A to Subpart C of... - Model Form of Loan Contract for Electric Distribution Borrowers

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 11 2013-01-01 2013-01-01 false Model Form of Loan Contract for Electric Distribution Borrowers A Appendix A to Subpart C of Part 1718 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE LOAN SECURITY DOCUMENTS FOR ELECTRIC BORROWERS Loan Contracts With Distribution...

  13. 7 CFR Appendix A to Subpart C of... - Model Form of Loan Contract for Electric Distribution Borrowers

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 11 2012-01-01 2012-01-01 false Model Form of Loan Contract for Electric Distribution Borrowers A Appendix A to Subpart C of Part 1718 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE LOAN SECURITY DOCUMENTS FOR ELECTRIC BORROWERS Loan Contracts With Distribution...

  14. In vitro models to study mechanisms involved in cyclosporine A-mediated glomerular contraction.

    PubMed

    L'Azou, B; Medina, J; Frieauff, W; Cordier, A; Cambar, J; Wolf, A

    1999-08-01

    The immunosuppressive drug, cyclosporin A (CsA), which is successfully used to prevent rejection in organ transplantation, induces renal side-effects as shown by a decrease in glomerular filtration rate and ultrafiltration coefficient regulated by the tone of mesangial cells.The aim of the present study was to investigate the effect of CsA on isolated glomeruli and mesangial cells, which constitute appropriate in vitro models for renal vasoreactivity studies. The roles of different intracellular and extracellular mediators such as calcium, endothelin-1 (ET-1), prostaglandins (TXA(2 )and PGI(2)) and reactive oxygen intermediates (ROIs) were analysed. CsA caused a concentration- and time-dependent decrease in the planar cross-sectional areas of isolated glomeruli and mesangial cells as determined by image analysis. Intracytosolic free calcium concentration determined by fluorimetric analysis was significantly increased after 30 min CsA (10 microM) incubation. In the contraction experiment, the calcium antagonist verapamil inhibited the CsA response. ET-1, TXB(2) and keto-PGF(1alpha) were determined directly, however no changes were found statistically significantly different from respective controls. In contrast to these results, the ET-1 specific antibody was able to reduce CsA-mediated cell contraction. In the presence of a prostacyclin agonist iloprost, CsA-induced contraction was also modified. The role of ROIs using a 2'7'-dichlorofluorescein diacetate (DCFdAc) fluorimetric method was directly determined by observing, with 10 microM CsA, a significant production of hydrogen peroxide (H(2)O(2)), which was able alone to induce mesangial cell contraction. Coincubation with the antioxidants led to a significant inhibition of mesangial cell contraction. These results suggest that CsA caused an imbalance in the normal level of all investigated vasoconstrictive and vasodilator mediators, which shifted towards the advantage of vasoconstrictive action.

  15. Supporting the Serial in the SERIOL Model

    ERIC Educational Resources Information Center

    Whitney, Carol

    2008-01-01

    It is commonly assumed that orthographical lexical access in visual word recognition takes place in parallel, with all letters activated at the same time. In contrast, in the SERIOL model of letter-position encoding, letters fire sequentially (Whitney, 2001). I present further support for such seriality on several fronts. (1) The reasons that led…

  16. Modelling public support for wildland fire policy

    Treesearch

    J.D. Absher; J.J. Vaske

    2007-01-01

    Theoretically grounded explanations of wildland fire policy can be improved by empirically documenting the causal influences of support for (or opposition to) management alternatives. This chapter proposes a model based on the specificity principle (i.e. correspondence between measured variables to empirically examine four common wildland fire policies in relation to...

  17. A continuum model of contraction waves and protoplasm streaming in strands of Physarum plasmodium.

    PubMed

    Teplov, V A; Romanovsky YuM; Latushkin, O A

    1991-01-01

    We present a mathematical model for continuously distributed mechanochemical autooscillations (autowaves) in a protoplasmic strand of Physarum polycephalum. The model is based on a hypothesis of local positive feedback between deformation and contraction of the contractile apparatus. This feedback is mediated through a cell regulatory system whose kinetics involves coupling to mechanical strain. Mathematical analysis and computer simulations have demonstrated that the solutions of the model agree quantitatively with the available experimental data. In particular, hydrodynamic interaction alone, between different sections of the strand via the streaming endoplasm, is capable of inducing the characteristic contractile behavior.

  18. Simulating the activation, contraction and movement of skeletal muscles using the bidomain model.

    PubMed

    Lopez Rincon, A; Cantu, C; Soto, R; Shimoda, S

    2016-08-01

    A simulation of the muscle activation, contraction and movement is here presented. This system was developed based on the Bidomain mathematical model of the electrical propagation in muscles. This study shows an electrical stimuli input to a muscle and how this behave. The comparison between healthy subject and patient with muscle activation impairment is depicted, depending on whether the signal reaches a threshold. A 3D model of a bicep muscle and a forearm bone connected was constructed using OpenGL. This platform could be used for development of controllers for biomechatronic systems in future works. This kind of bioinspired model could be used for a better understanding of the neuromotor system.

  19. A model of membrane contraction predicting initiation and completion of bacterial cell division.

    PubMed

    Dow, Claire E; Rodger, Alison; Roper, David I; van den Berg, Hugo A

    2013-05-01

    Bacterial cell division involves a complex and dynamic sequence of events whereby polymers of the protein FtsZ assemble at the division plane and rearrange to achieve the goal of contracting the cell membrane at the site of cell division, thus dividing the parent cell into two daughter cells. We present a mathematical model (which we refer to as CAM-FF: Critical Accumulation of Membrane-bound FtsZ Fibres) of the assembly of the contractile ring in terms of the accumulation of short linear polymers of FtsZ that associate and dissociate from the cell membrane. In prokaryotes, the biochemical function of FtsZ is thought to underpin the assembly and at least the initial kinetic force of ring contraction. Our model extends earlier work of Surovtsev et al. [PLoS Comput. Biol., 2008, 4, e1000102] by adding (i) the kinetics of FtsZ accumulation on cell membrane anchor proteins and (ii) the physical forces required to deform the cell against its surface tension. Moreover, we provide a more rigorous treatment of intracellular diffusion and we revise some of the model parameter values in light of the experimental evidence now available. We derive a critical contraction parameter which links the chemical population dynamics of membrane-bound FtsZ molecules to the force of contraction. Using this parameter as a tool to predict the ability of the cell to initiate division, we are able to predict the division outcome in cells depleted of key FtsZ-binding proteins.

  20. β-adrenergic effects on cardiac myofilaments and contraction in an integrated rabbit ventricular myocyte model

    PubMed Central

    Negroni, Jorge A.; Morotti, Stefano; Lascano, Elena C.; Gomes, Aldrin V.; Grandi, Eleonora; Puglisi, José L; Bers, Donald M.

    2015-01-01

    A five-state model of myofilament contraction was integrated into a well-established rabbit ventricular myocyte model of ion channels, Ca2+ transporters and kinase signaling to analyze the relative contribution of different phosphorylation targets to the overall mechanical response driven by β-adrenergic stimulation (β-AS). β-AS effect on sarcoplasmic reticulum Ca2+ handling, Ca2+, K+ and Cl− currents, and Na+/K+-ATPase properties were included based on experimental data. The inotropic effect on the myofilaments was represented as reduced myofilament Ca2+ sensitivity (XBCa) and titin stiffness, and increased cross-bridge (XB) cycling rate (XBcy). Assuming independent roles of XBCa and XBcy, the model reproduced experimental β-AS responses on action potentials and Ca2+ transient amplitude and kinetics. It also replicated the behavior of force-Ca2+, release-restretch, length-step, stiffness-frequency and force-velocity relationships, and increased force and shortening in isometric and isotonic twitch contractions. The β-AS effect was then switched off from individual targets to analyze their relative impact on contractility. Preventing β-AS effects on L-type Ca2+ channels or phospholamban limited Ca2+ transients and contractile responses in parallel, while blocking phospholemman and K+ channel (IKs) effects enhanced Ca2+ and inotropy. Removal of β-AS effects from XBCa enhanced contractile force while decreasing peak Ca2+ (due to greater Ca2+ buffering), but had less effect on shortening. Conversely, preventing β-AS effects on XBcy preserved Ca2+ transient effects, but blunted inotropy (both isometric force and especially shortening). Removal of titin effects had little impact on contraction. Finally, exclusion of β-AS from XBCa and XBcy while preserving effects on other targets resulted in preserved peak isometric force response (with slower kinetics) but nearly abolished enhanced shortening. β-AS effects on XBCa vs. XBcy have greater impact on isometric

  1. β-adrenergic effects on cardiac myofilaments and contraction in an integrated rabbit ventricular myocyte model.

    PubMed

    Negroni, Jorge A; Morotti, Stefano; Lascano, Elena C; Gomes, Aldrin V; Grandi, Eleonora; Puglisi, José L; Bers, Donald M

    2015-04-01

    A five-state model of myofilament contraction was integrated into a well-established rabbit ventricular myocyte model of ion channels, Ca(2+) transporters and kinase signaling to analyze the relative contribution of different phosphorylation targets to the overall mechanical response driven by β-adrenergic stimulation (β-AS). β-AS effect on sarcoplasmic reticulum Ca(2+) handling, Ca(2+), K(+) and Cl(-) currents, and Na(+)/K(+)-ATPase properties was included based on experimental data. The inotropic effect on the myofilaments was represented as reduced myofilament Ca(2+) sensitivity (XBCa) and titin stiffness, and increased cross-bridge (XB) cycling rate (XBcy). Assuming independent roles of XBCa and XBcy, the model reproduced experimental β-AS responses on action potentials and Ca(2+) transient amplitude and kinetics. It also replicated the behavior of force-Ca(2+), release-restretch, length-step, stiffness-frequency and force-velocity relationships, and increased force and shortening in isometric and isotonic twitch contractions. The β-AS effect was then switched off from individual targets to analyze their relative impact on contractility. Preventing β-AS effects on L-type Ca(2+) channels or phospholamban limited Ca(2+) transients and contractile responses in parallel, while blocking phospholemman and K(+) channel (IKs) effects enhanced Ca(2+) and inotropy. Removal of β-AS effects from XBCa enhanced contractile force while decreasing peak Ca(2+) (due to greater Ca(2+) buffering), but had less effect on shortening. Conversely, preventing β-AS effects on XBcy preserved Ca(2+) transient effects, but blunted inotropy (both isometric force and especially shortening). Removal of titin effects had little impact on contraction. Finally, exclusion of β-AS from XBCa and XBcy while preserving effects on other targets resulted in preserved peak isometric force response (with slower kinetics) but nearly abolished enhanced shortening. β-AS effects on XBCa and XBcy

  2. Life cycle cost-based risk model for energy performance contracting retrofits

    NASA Astrophysics Data System (ADS)

    Berghorn, George H.

    Buildings account for 41% of the primary energy consumption in the United States, nearly half of which is accounted for by commercial buildings. Among the greatest energy users are those in the municipalities, universities, schools, and hospitals (MUSH) market. Correctional facilities are in the upper half of all commercial building types for energy intensity. Public agencies have experienced reduced capital budgets to fund retrofits; this has led to the increased use of energy performance contracts (EPC), which are implemented by energy services companies (ESCOs). These companies guarantee a minimum amount of energy savings resulting from the retrofit activities, which in essence transfers performance risk from the owner to the contractor. Building retrofits in the MUSH market, especially correctional facilities, are well-suited to EPC, yet despite this potential and their high energy intensities, efficiency improvements lag behind that of other public building types. Complexities in project execution, lack of support for data requests and sub-metering, and conflicting project objectives have been cited as reasons for this lag effect. As a result, project-level risks must be understood in order to support wider adoption of retrofits in the public market, in particular the correctional facility sub-market. The goal of this research is to understand risks related to the execution of energy efficiency retrofits delivered via EPC in the MUSH market. To achieve this goal, in-depth analysis and improved understanding was sought with regard to ESCO risks that are unique to EPC in this market. The proposed work contributes to this understanding by developing a life cycle cost-based risk model to improve project decision making with regard to risk control and reduction. The specific objectives of the research are: (1) to perform an exploratory analysis of the EPC retrofit process and identify key areas of performance risk requiring in-depth analysis; (2) to construct a

  3. Normality Index of Ventricular Contraction Based on a Statistical Model from FADS

    PubMed Central

    Jiménez-Ángeles, Luis; Valdés-Cristerna, Raquel; Vallejo, Enrique; Bialostozky, David; Medina-Bañuelos, Verónica

    2013-01-01

    Radionuclide-based imaging is an alternative to evaluate ventricular function and synchrony and may be used as a tool for the identification of patients that could benefit from cardiac resynchronization therapy (CRT). In a previous work, we used Factor Analysis of Dynamic Structures (FADS) to analyze the contribution and spatial distribution of the 3 most significant factors (3-MSF) present in a dynamic series of equilibrium radionuclide angiography images. In this work, a probability density function model of the 3-MSF extracted from FADS for a control group is presented; also an index, based on the likelihood between the control group's contraction model and a sample of normal subjects is proposed. This normality index was compared with those computed for two cardiopathic populations, satisfying the clinical criteria to be considered as candidates for a CRT. The proposed normality index provides a measure, consistent with the phase analysis currently used in clinical environment, sensitive enough to show contraction differences between normal and abnormal groups, which suggests that it can be related to the degree of severity in the ventricular contraction dyssynchrony, and therefore shows promise as a follow-up procedure for patients under CRT. PMID:23634177

  4. Normality index of ventricular contraction based on a statistical model from FADS.

    PubMed

    Jiménez-Ángeles, Luis; Valdés-Cristerna, Raquel; Vallejo, Enrique; Bialostozky, David; Medina-Bañuelos, Verónica

    2013-01-01

    Radionuclide-based imaging is an alternative to evaluate ventricular function and synchrony and may be used as a tool for the identification of patients that could benefit from cardiac resynchronization therapy (CRT). In a previous work, we used Factor Analysis of Dynamic Structures (FADS) to analyze the contribution and spatial distribution of the 3 most significant factors (3-MSF) present in a dynamic series of equilibrium radionuclide angiography images. In this work, a probability density function model of the 3-MSF extracted from FADS for a control group is presented; also an index, based on the likelihood between the control group's contraction model and a sample of normal subjects is proposed. This normality index was compared with those computed for two cardiopathic populations, satisfying the clinical criteria to be considered as candidates for a CRT. The proposed normality index provides a measure, consistent with the phase analysis currently used in clinical environment, sensitive enough to show contraction differences between normal and abnormal groups, which suggests that it can be related to the degree of severity in the ventricular contraction dyssynchrony, and therefore shows promise as a follow-up procedure for patients under CRT.

  5. Finite element modeling reveals complex strain mechanics in the aponeuroses of contracting skeletal muscle.

    PubMed

    Chi, Sheng-Wei; Hodgson, John; Chen, Jiun-Shyan; Reggie Edgerton, V; Shin, David D; Roiz, Ronald A; Sinha, Shantanu

    2010-05-07

    A finite element model was used to investigate the counter-intuitive experimental observation that some regions of the aponeuroses of a loaded and contracting muscle may shorten rather than undergo an expected lengthening. The model confirms the experimental findings and suggests that pennation angle plays a significant role in determining whether regions of the aponeuroses stretch or shorten. A smaller pennation angles (25 degrees ) was accompanied by aponeurosis lengthening whereas a larger pennation angle (47 degrees ) was accompanied by mixed strain effects depending upon location along the length of the aponeurosis. This can be explained by the Poisson effect during muscle contraction and a Mohr's circle analogy. Constant volume constraint requires that fiber cross sectional dimensions increase when a fiber shortens. The opposing influences of these two strains upon the aponeurosis combine in proportion to the pennation angle. Lower pennation angles emphasize the influence of fiber shortening upon the aponeurosis and thus favor aponeurosis compression, whereas higher pennation angles increase the influence of cross sectional changes and therefore favor aponeurosis stretch. The distance separating the aponeuroses was also found to depend upon pennation angle during simulated contractions. Smaller pennation angles favored increased aponeurosis separation larger pennation angles favored decreased separation. These findings caution that measures of the mechanical properties of aponeuroses in intact muscle may be affected by contributions from adjacent muscle fibers and that the influence of muscle fibers on aponeurosis strain will depend upon the fiber pennation angle.

  6. Which Process Model Practices Support Project Success?

    NASA Astrophysics Data System (ADS)

    Lepmets, Marion

    In this research the relevance of the guidance of software process models to industry was studied - more precisely, how relevant are the basic project management practices to the industry projects and to the success of these projects. The focus of the research is on project management and its related practices - the processes that support the achievement of capability levels 1 and 2 in CMMI and ISO/IEC 15504. These project management practices can also be viewed as best practices, the application of which can lead to project success. We aimed to discover whether the implementation of basic project management practices supports project success. There is evidence that higher process capability supports increased project performance. The question remains about the significance of basic project management practices to project performance.

  7. Contracts and Contracting: A Primer.

    PubMed

    Terra, Sandra M; Zimmerling, John

    2016-01-01

    The underlying guiding principles of case management services and practices of the Case Management Body of Knowledge include the following: "Case managers must possess the education, skills, knowledge, competencies, and experiences needed to effectively render appropriate, safe, and quality services to clients/support systems" and "Case management services are offered according to the clients' benefits as stipulated in their health insurance plans (http://www.cmbodyofknowledge.com/content/case-management-knowledge-2). Fulfilling these principles requires that the case manager engage in negotiating and contract execution.This article explores the concepts of negotiation and some of the many ways case managers contribute to the contracting process. Acute care hospitals, individual practice, managed care. Case managers can provide valuable information during the contracting process, in many settings. In the managed care arena, case management can help identify the types of services needed by the population the organization serves. The same understanding of data can assist during the payer contracting process in the acute care setting and ensure that the hospital is fairly reimbursed by third party payers. The independent practitioners will, undoubtedly, face the need to negotiate for themselves as well as their clients. The case manager, regardless of the setting, benefits from an understanding of the principles and processes associated with negotiation and contracting.

  8. 48 CFR 39.107 - Contract clause.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CONTRACTING ACQUISITION OF INFORMATION TECHNOLOGY General 39.107 Contract clause. The contracting officer..., in solicitations and contracts for information technology which require security of information... information technology services or support services....

  9. A continuum theory of Allen's frontal contraction model of amoeboid pseudopodium extension.

    PubMed

    Odell, G M

    1977-03-01

    A continuum theory is proposed for the chemically controlled cytoplasmic streaming observed in pseudopodium extension in Chaos Carolinensis. Amoeboid cytoplasm is assumed to consist of submicroscopic contractile fibers bathed by viscous fluid. The fiber constituent models the actin-like and myosin-like contractile machinery known to be present in Chaos Carolinensis cytoplasm. A "trigger chemical", produced at the pseudopodium tip, moves by diffusion in, and convection by, the viscous fluid, and causes the contractile fibers to contract in their own length. The contracting fibers, attached at the tip and running continuously back toward the amoeba cell body, pull the fluid constituent of the cytoplasm forward and ultimately crosslink to form the outer gel tube of the advancing pseudopodium. That is, streaming cytoplasm is modeled as a two constituent porous medium, with the fluid constituent free to flow through a porous matrix of oriented (contractile fiber) rods, while the matrix of rods itself moves as the fibers contract, with fiber contraction controlled by a trigger chemical born by the fluid constituent. According to this theory, in the region behind the advancing pseudopodium tip, the contractile fiber rods move forward toward the tip faster than the fluid constituent. The hydrostatic pressure in the fluid therefore increases from the cell body toward the tip (Just the opposite from flow driven by pressure excess generated in the cell body). The excess of hydrostatic pressure above ambient built up at the tip provides the force to roll out the advancing pseudopodium tip. The cell membrane plays no active mechanical role. The mathematical transcription makes a precise theory of R. D. Allen's "frontal (or fountain zone) contraction model". The general system of coupled, non-linear, partial differential equations is solved for its simplest non-trivial special case, that of a steady-state motion, as seen from a coordinate system attached to the advancing tip

  10. Transonic Cascade Measurements to Support Analytical Modeling

    DTIC Science & Technology

    2007-11-02

    RECEIVED JUL 0 12005 FINAL REPORT FOR: AFOSR GRANT F49260-02-1-0284 TRANSONIC CASCADE MEASUREMENTS TO SUPPORT ANALYTICAL MODELING Paul A. Durbin ...PAD); 650-723-1971 (JKE) durbin @vk.stanford.edu; eaton@vk.stanford.edu submitted to: Attn: Dr. John Schmisseur Air Force Office of Scientific Research...both spline and control points for subsequent wall shape definitions. An algebraic grid generator was used to generate the grid for the blade-wall

  11. Personnel Service Support (PSS) in Army Models

    DTIC Science & Technology

    1989-10-20

    UNCLASSIFIED N ACN 73765 PERSONNEL SERVICE SUPPORT (PSS) IN ARMY MODELS FINAL REPORT DEPARTMENT OF THE ARMY HEADQUARTERS UNITED STATES ARMY TRAINING...Analysis 4-7 A-6 10 Theater Strategic Operational (TSO) Depths B-3 11 Constructing Interval Scales from Ordinal Data E-4 vii GLOSSARY OF ACRONYMS ACN Army...Control Number AI Artificial Intelligence AIDS Acquired Immune Deficiency Syndrome ALB Airland Battle AMSAA Army Materiel Systems Analysis Agency ANSI

  12. Finite element model of intramuscular pressure during isometric contraction of skeletal muscle.

    PubMed

    Jenkyn, Thomas R; Koopman, Bart; Huijing, Peter; Lieber, Richard L; Kaufman, Kenton R

    2002-11-21

    The measurement of in vivo intramuscular pressure (IMP) has recently become practical and IMP appears well correlated with muscle tension. A numerical model of skeletal muscle was developed to examine the mechanisms producing IMP. Unipennate muscle is modelled as a two-dimensional material continuum that is incompressible and nonlinearly anisotropic. The finite element technique is used to calculate IMP and muscle stress during passive stretch and during isometric contraction. A novel element models the contractile portion of muscle, incorporating sarcomere length-force and velocity-force relations. A range of unipennate muscle geometries can be modelled. The model was configured to simulate the rabbit tibialis anterior muscle over a range of lengths. Simulated IMP and stress results were validated against animal experimentation data. The simulation agreed well with the experimental data over the range of 0.8-1.1 of the optimal length. Severe pressure gradients were produced near the musculo-tendinous junctions while IMP was more uniform in the central muscle belly. IMP and muscle stress in relaxed (unstimulated) muscle increased nonlinearly with muscle length. IMP and stress in isometrically contracting muscle showed a local maximum at optimal length and were reduced at shorter lengths. At muscle lengths longer than optimal, stress and IMP increased predominately due to tension in the passive elastic structures.

  13. Response of Dark Matter Halos to Condensation of Baryons: Cosmological Simulations and Improved Adiabatic Contraction Model

    NASA Astrophysics Data System (ADS)

    Gnedin, Oleg Y.; Kravtsov, Andrey V.; Klypin, Anatoly A.; Nagai, Daisuke

    2004-11-01

    The cooling of gas in the centers of dark matter halos is expected to lead to a more concentrated dark matter distribution. The response of dark matter to the condensation of baryons is usually calculated using the model of adiabatic contraction, which assumes spherical symmetry and circular orbits. In contrast, halos in the hierarchical structure formation scenarios grow via multiple violent mergers and accretion along filaments, and particle orbits in the halos are highly eccentric. We study the effects of the cooling of gas in the inner regions of halos using high-resolution cosmological simulations that include gas dynamics, radiative cooling, and star formation. We find that the dissipation of gas indeed increases the density of dark matter and steepens its radial profile in the inner regions of halos compared to the case without cooling. For the first time, we test the adiabatic contraction model in cosmological simulations and find that the standard model systematically overpredicts the increase of dark matter density in the inner 5% of the virial radius. We show that the model can be improved by a simple modification of the assumed invariant from M(r)r to M(r)r, where r and r are the current and orbit-averaged particle positions. This modification approximately accounts for orbital eccentricities of particles and reproduces simulation profiles to within 10%-20%. We present analytical fitting functions that accurately describe the transformation of the dark matter profile in the modified model and can be used for interpretation of observations.

  14. Authoring Tools and Methods for Adaptive Training and Education in Support of the US Army Learning Model: Research Outline

    DTIC Science & Technology

    2015-10-01

    the US Army Learning Model: Research Outline by Scott Ososky, Robert Sottilare, Keith Brawner, Rodney Long, and Arthur Graesser...Education in Support of the US Army Learning Model: Research Outline by Scott Ososky Oak Ridge Associated Universities, Oak Ridge, TN Robert...Support of the US Army Learning Model: Research Outline 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Scott

  15. Supporting observation campaigns with high resolution modeling

    NASA Astrophysics Data System (ADS)

    Klocke, Daniel; Brueck, Matthias; Voigt, Aiko

    2017-04-01

    High resolution simulation in support of measurement campaigns offers a promising and emerging way to create large-scale context for small-scale observations of clouds and precipitation processes. As these simulation include the coupling of measured small-scale processes with the circulation, they also help to integrate the research communities from modeling and observations and allow for detailed model evaluations against dedicated observations. In connection with the measurement campaign NARVAL (August 2016 and December 2013) simulations with a grid-spacing of 2.5 km for the tropical Atlantic region (9000x3300 km), with local refinement to 1.2 km for the western part of the domain, were performed using the icosahedral non-hydrostatic (ICON) general circulation model. These simulations are again used to drive large eddy resolving simulations with the same model for selected days in the high definition clouds and precipitation for advancing climate prediction (HD(CP)2) project. The simulations are presented with the focus on selected results showing the benefit for the scientific communities doing atmospheric measurements and numerical modeling of climate and weather. Additionally, an outlook will be given on how similar simulations will support the NAWDEX measurement campaign in the North Atlantic and AC3 measurement campaign in the Arctic.

  16. Impaired contraction and decreased detrusor innervation in a female rat model of pelvic neuropraxia

    PubMed Central

    Hannan, Johanna L.; Powers, Shelby A.; Wang, Vinson M.; Castiglione, Fabio; Hedlund, Petter; Bivalacqua, Trinity J.

    2017-01-01

    Introduction and hypothesis Bilateral pelvic nerve injury (BPNI) is a model of post-radical hysterectomy neuropraxia, a common sequelae. This study assessed the time course of changes to detrusor autonomic innervation, smooth muscle (SM) content and cholinergic-mediated contraction post-BPNI. Methods Female Sprague-Dawley rats underwent BPNI or sham surgery and were evaluated 3, 7, 14 and 30 days post-BPNI (n=8/group). Electrical field stimulated (EFS) and carbachol-induced contractions were measured. Gene expression was assessed by qPCR for muscarinic receptor types 2 (M2) and 3 (M3), collagen type 1α1 and 3α1 and SM actin. Western blots measured M2 and M3 protein expression. Bladder sections were stained with Masson’s trichrome for SM content and immunofluorescence staining for nerve terminals expressing vesicular acetylcholine transporter (VAChT), tyrosine hydroxylase (TH) and neuronal nitric oxide synthase (nNOS). Results BPNI caused larger bladders with less SM content and increased collagen type 1α1 and 3α1 gene expression. At early time points, cholinergic-mediated contraction increased, while EFS-mediated contraction decreased and returned to baseline by 30 days. Protein and gene expression of M3 was decreased 3 and 7 days post-BPNI while M2 was unchanged. TH nerve terminals surrounding the detrusor decreased in all BPNI groups while VAChT and nNOS terminals decreased 14 and 30 days post-BPNI. Conclusions BPNI increased bladder size, impaired contractility and decreased SM and autonomic innervation. Therapeutic strategies preventing nerve injury-mediated decline in neuronal input and SM content may prevent the development of a neurogenic bladder and improve quality of life after invasive pelvic surgery. PMID:27987021

  17. Impaired contraction and decreased detrusor innervation in a female rat model of pelvic neuropraxia.

    PubMed

    Hannan, Johanna L; Powers, Shelby A; Wang, Vinson M; Castiglione, Fabio; Hedlund, Petter; Bivalacqua, Trinity J

    2017-07-01

    Bilateral pelvic nerve injury (BPNI) is a model of post-radical hysterectomy neuropraxia, a common sequela. This study assessed the time course of changes to detrusor autonomic innervation, smooth muscle (SM) content and cholinergic-mediated contraction post-BPNI. Female Sprague-Dawley rats underwent BPNI or sham surgery and were evaluated 3, 7, 14, and 30 days post-BPNI (n = 8/group). Electrical field-stimulated (EFS) and carbachol-induced contractions were measured. Gene expression was assessed by qPCR for muscarinic receptor types 2 (M2) and 3 (M3), collagen type 1α1 and 3α1, and SM actin. Western blots measured M2 and M3 protein expression. Bladder sections were stained with Masson's trichrome for SM content and immunofluorescence staining for nerve terminals expressing vesicular acetylcholine transporter (VAChT), tyrosine hydroxylase (TH), and neuronal nitric oxide synthase (nNOS). Bilateral pelvic nerve injury caused larger bladders with less SM content and increased collagen type 1α1 and 3α1 gene expression. At early time points, cholinergic-mediated contraction increased, whereas EFS-mediated contraction decreased and returned to baseline by 30 days. Protein and gene expression of M3 was decreased 3 and 7 days post-BPNI, whereas M2 was unchanged. TH nerve terminals surrounding the detrusor decreased in all BPNI groups, whereas VAChT and nNOS terminals decreased 14 and 30 days post-BPNI. Bilateral pelvic nerve injury increased bladder size, impaired contractility, and decreased SM and autonomic innervation. Therapeutic strategies preventing nerve injury-mediated decline in neuronal input and SM content may prevent the development of a neurogenic bladder and improve quality of life after invasive pelvic surgery.

  18. Contracts for field projects and supporting research on enhanced oil recovery. Progress review No. 78, quarter ending March 31, 1994

    SciTech Connect

    1995-05-01

    This report presents descriptions of various research projects and field projects concerned with the enhanced recovery of petroleum. Contract numbers, principal investigators, company names, and project management information is included.

  19. Contracts for field projects and supporting research on enhanced oil recovery. Progress review number 83, quarter ending June 30, 1995

    SciTech Connect

    1996-08-01

    Summaries of 41 research projects on enhanced recovery are presented under the following sections: (1) chemical flooding; (2) gas displacement; (3) thermal recovery; (4) geoscience technology; (5) resource assessment technology; and (6) reservoir classes. Each presentation gives the title of the project, contract number, research facility, contract date, expected completion data, amount of the award, principal investigator, and DOE program manager, and describes the objectives of the project and a summary of the technical progress.

  20. Pricing and Escalation Issues Weaken the Effectiveness of the Army Contract With Sikorsky to Support the Corpus Christi Army Depot

    DTIC Science & Technology

    2011-09-08

    Honeywell Rotor under a long- term contract that uses a process called “one-pass pricing.” In one-pass pricing, a group of DoD pricing experts provides real...e P ted on ® Recycled Peper C REPLY TO ATTENTION OF· AMSCC·IR DEPARTMENT OF THE ARMY u.s. ARMY CONTRACTING COMMAND 3334A WELLS ROAD REDSTONE

  1. Adaptations to exercise training and contraction-induced muscle injury in animal models of muscular dystrophy.

    PubMed

    Carter, Gregory T; Abresch, R Ted; Fowler, William M

    2002-11-01

    This article reviews the current status of exercise training and contraction-induced muscle-injury investigations in animal models of muscular dystrophy. Most exercise-training studies have compared the adaptations of normal and dystrophic muscles with exercise. Adaptation of diseased muscle to exercise occurs at many levels, starting with the extracellular matrix, but also involves cytoskeletal architecture, muscle contractility, repair mechanisms, and gene regulation. The majority of exercise-injury investigations have attempted to determine the susceptibility of dystrophin-deficient muscles to contraction-induced injury. There is some evidence in animal models that diseased muscle can adapt and respond to mechanical stress. However, exercise-injury studies show that dystrophic muscles have an increased susceptibility to high mechanical forces. Most of the studies involving exercise training have shown that muscle adaptations in dystrophic animals were qualitatively similar to the adaptations observed in control muscle. Deleterious effects of the dystrophy usually occur only in older animals with advanced muscle fiber degeneration or after high-resistive eccentric training. The main limitations in applying these conclusions to humans are the differences in phenotypic expression between humans and genetically homologous animal models and in the significant biomechanical differences between humans and these animal models.

  2. A Tired Light/Contracting Universe Model from the Union2.1 Supernovae Data

    NASA Astrophysics Data System (ADS)

    Glover, John

    A tired light/contracting universe (TLCU) model is shown to be an excellent fit to the redshift/distance modulus data for the 580 supernovae 1a in the Union2.1 compilation. The data reveal that the Milky Way is in a static region with a radius of about 450Mpc. Beyond the static region the universe is contracting with a space velocity which is linearly proportional to distance over the whole range of the data (k = -7.6 ± 2.3 km s-1 Mpc-1). The other constant of the model is the Hubble constant for which a value of H = 69.51 ± 0.86 km s-1 Mpc-1 is obtained. The fit of the TLCU model to the Union2.1 data is at least as good as the fit of the two constant ΛCDM model to the same data. A formula for photon travel distance is derived and an experiment for the possible detection of the tired light process is proposed.

  3. Characteristics of Hydraulic Shock Waves in an Inclined Chute Contraction by Using Three Dimensional Numerical Model

    NASA Astrophysics Data System (ADS)

    Hsiao, Kai-Wen; Hsu, Yu-Chao; Jan, Chyan-Deng; Su, Yu-Wen

    2016-04-01

    The inclined rectangular chute construction is a common structure used in hydraulic engineering for typical reasons such as the increase of bottom slope, the transition from side channel intakes to tunnel spillways, the drainage construction, and the reduction of chute width due to bridges, flood diversion structures or irrigation systems. The converging vertical sidewalls of a chute contraction deflect the supercritical flow to form hydraulic shock waves. Hydraulic shock waves have narrow and locally extreme wavy surfaces, which commonly results in the requirement of higher height of sidewalls. Therefore, predicting the possible height and position of maximum hydraulic shock wave are necessary to design the required height of sidewalls to prevent flow overtopping. In this study, we used a three-dimensional computation fluid dynamics model (i.e., FLOW-3D) to simulate the characteristics of hydraulic shock waves in an inclined chute contraction. For this purpose, the parameters of simulated hydraulic shock wave, such as the shock angle, maximum shock wave height and maximum shock wave position in various conditions are compared with those calculated by the empirical relations obtained from literatures. We showed that the simulated results are extremely close to the experimental results. The numerical results validated the applicability of these empirical relations and extend their applicability to higher approach Froude numbers from 3.51 to 7.27. Furthermore, we also applied the Yuan-Shan-Tsu flood diversion channel under 200-year peak flow condition to FLOW-3D model to simulate the hydraulic shock waves and validate the effect of the installation of a diversion pier in the channel on promoting the stability of flow fluid. The results revealed that a diversion pier installed in the Yuan-Shan-Tsu flood diversion channel is helpful for improving the stability of flow field. In summary, this study demonstrates that FLOW-3D model can be used to simulate the

  4. Paleoclimatic modeling and phylogeography of least killifish, Heterandria formosa: insights into Pleistocene expansion-contraction dynamics and evolutionary history of North American Coastal Plain freshwater biota.

    PubMed

    Bagley, Justin C; Sandel, Michael; Travis, Joseph; Lozano-Vilano, María de Lourdes; Johnson, Jerald B

    2013-10-09

    Climatic and sea-level fluctuations throughout the last Pleistocene glacial cycle (~130-0 ka) profoundly influenced present-day distributions and genetic diversity of Northern Hemisphere biotas by forcing range contractions in many species during the glacial advance and allowing expansion following glacial retreat ('expansion-contraction' model). Evidence for such range dynamics and refugia in the unglaciated Gulf-Atlantic Coastal Plain stems largely from terrestrial species, and aquatic species Pleistocene responses remain relatively uninvestigated. Heterandria formosa, a wide-ranging regional endemic, presents an ideal system to test the expansion-contraction model within this biota. By integrating ecological niche modeling and phylogeography, we infer the Pleistocene history of this livebearing fish (Poeciliidae) and test for several predicted distributional and genetic effects of the last glaciation. Paleoclimatic models predicted range contraction to a single southwest Florida peninsula refugium during the Last Glacial Maximum, followed by northward expansion. We inferred spatial-population subdivision into four groups that reflect genetic barriers outside this refuge. Several other features of the genetic data were consistent with predictions derived from an expansion-contraction model: limited intraspecific divergence (e.g. mean mtDNA p-distance = 0.66%); a pattern of mtDNA diversity (mean Hd = 0.934; mean π = 0.007) consistent with rapid, recent population expansion; a lack of mtDNA isolation-by-distance; and clinal variation in allozyme diversity with higher diversity at lower latitudes near the predicted refugium. Statistical tests of mismatch distributions and coalescent simulations of the gene tree lent greater support to a scenario of post-glacial expansion and diversification from a single refugium than to any other model examined (e.g. multiple-refugia scenarios). Congruent results from diverse data indicate H. formosa fits the classic Pleistocene

  5. A three-dimensional chemo-mechanical continuum model for smooth muscle contraction.

    PubMed

    Böl, Markus; Schmitz, André; Nowak, Götz; Siebert, Tobias

    2012-09-01

    Based on two fields, namely the placement and the calcium concentration, a chemo-mechanically coupled three-dimensional model, describing the contractile behaviour of smooth muscles, is presented by means of a strain energy function. The strain energy function (Schmitz and Böl, 2011) is additively decomposed into a passive part, relating to elastin and collagen, and an active calcium-driven part related to the chemical contraction of the smooth muscle cells. For the description of the calcium phase the four state cross-bridge model of Hai and Murphy (Hai and Murphy, 1988) has been implemented into the finite element method. Beside three-dimensional illustrative boundary-value problems demonstrating the features of the presented modelling concept, simulations on an idealised artery document the applicability of the model to more realistic geometries.

  6. PV System 'Availability' as a Reliability Metric -- Improving Standards, Contract Language and Performance Models

    SciTech Connect

    Klise, Geoffrey T.; Hill, Roger; Walker, Andy; Dobos, Aron; Freeman, Janine

    2016-11-21

    The use of the term 'availability' to describe a photovoltaic (PV) system and power plant has been fraught with confusion for many years. A term that is meant to describe equipment operational status is often omitted, misapplied or inaccurately combined with PV performance metrics due to attempts to measure performance and reliability through the lens of traditional power plant language. This paper discusses three areas where current research in standards, contract language and performance modeling is improving the way availability is used with regards to photovoltaic systems and power plants.

  7. Modelling of thermal contraction of emplaced lava flows at Hekla volcano

    NASA Astrophysics Data System (ADS)

    Wittmann, Werner; Sigmundsson, Freysteinn; Dumont, Stéphanie; Ofeigsson, Benedikt G.

    2014-05-01

    During and after the emplacement of magma the flow cools down and undergoes thermal contraction. This latter process leads to subsidence of the emplaced lava relative to its surrounding area, and thus masking the overall current crustal movement due to magma pressure changes in the volcanic system. Other effects such as void space compaction and the bending of the underlying elastic crust due to the weight of the lava accompany the emplacement and lead to further complications regarding the studies of thermal contraction. Interferometric synthetic aperture radar (InSAR) provides good possibilities for the detection and resolution of vertical movements around a volcano because of high spatial resolution and good accuracy during favorable conditions. Comparisons of the interferograms with the outline of lava flows at e.g. Hekla volcano or Mount Etna agree well with areas of higher subsidence or minor uplift, respectively, being taken as an eclipsing of the above-mentioned effects. Interferograms from 1993 to 2012 give evidence that the lava fields of the Hekla eruptions in 1991 and 2000 are continuously subsiding. Even there are several publications dealing with such observations, models taking into account a physical basis for thermal contraction are currently spare. Nevertheless, several theoretical approaches state the time-dependent temperature distribution within a lava flow taking into account heat-flow processes. On the basis of these calculations, we have developed a one-dimensional numerical model that shows the subsidence and subsidence rate after a certain time after emplacement. The model takes into account the conduction of heat away from the fluid magma towards the magma-air interface and the magma-rock interface. Furthermore, contraction at the transition boundary between the liquid phase of magma and the solidified gabbro are considered to be in the range of volume change of 9% according to density measurements. After full solidification the

  8. The early universe history from contraction-deformation of the Standard Model

    NASA Astrophysics Data System (ADS)

    Gromov, N. A.

    2017-03-01

    The elementary particles evolution in the early Universe from Plank time up to several milliseconds is presented. The developed theory is based on the high-temperature (high-energy) limit of the Standard Model which is generated by the contractions of its gauge groups. At the infinite temperature all particles lose masses. Only massless neutral -bosons, massless Z-quarks, neutrinos and photons are survived in this limit. The weak interactions become long-range and are mediated by neutral currents, quarks have only one color degree of freedom.

  9. Microscopic model of the actin-myosin interaction in muscular contractions

    NASA Astrophysics Data System (ADS)

    Gaveau, B.; Moreau, M.; Schuman, B.

    2004-01-01

    We define and study a detailed many body model for the muscular contraction taking into account the various myosin heads. The state of the system is defined by the position of the actin and by an internal coordinate of rotation for each myosin head. We write a system of Fokker-Planck equations and calculate the average for the position, the number of attached myosin heads, and the total force exerted on the actin. We also study the correlation between these quantities, in particular between the number of attached myosin heads and the force on the actin.

  10. A Three-Dimensional Simulation Model of Cardiomyocyte Integrating Excitation-Contraction Coupling and Metabolism

    PubMed Central

    Hatano, Asuka; Okada, Jun-ichi; Washio, Takumi; Hisada, Toshiaki; Sugiura, Seiryo

    2011-01-01

    Recent studies have revealed that Ca2+ not only regulates the contraction of cardiomyocytes, but can also function as a signaling agent to stimulate ATP production by the mitochondria. However, the spatiotemporal resolution of current experimental techniques limits our investigative capacity to understand this phenomenon. Here, we created a detailed three-dimensional (3D) cardiomyocyte model to study the subcellular regulatory mechanisms of myocardial energetics. The 3D cardiomyocyte model was based on the finite-element method, with detailed subcellular structures reproduced, and it included all elementary processes involved in cardiomyocyte electrophysiology, contraction, and ATP metabolism localized to specific loci. The simulation results were found to be reproducible and consistent with experimental data regarding the spatiotemporal pattern of cytosolic, intrasarcoplasmic-reticulum, and mitochondrial changes in Ca2+; as well as changes in metabolite levels. Detailed analysis suggested that although the observed large cytosolic Ca2+ gradient facilitated uptake by the mitochondrial Ca2+ uniporter to produce cyclic changes in mitochondrial Ca2+ near the Z-line region, the average mitochondrial Ca2+ changes slowly. We also confirmed the importance of the creatine phosphate shuttle in cardiac energy regulation. In summary, our 3D model provides a powerful tool for the study of cardiac function by overcoming some of the spatiotemporal limitations of current experimental approaches. PMID:22261047

  11. Cross-scale efficient tensor contractions for coupled cluster computations through multiple programming model backends

    DOE PAGES

    Ibrahim, Khaled Z.; Epifanovsky, Evgeny; Williams, Samuel; ...

    2017-03-08

    Coupled-cluster methods provide highly accurate models of molecular structure through explicit numerical calculation of tensors representing the correlation between electrons. These calculations are dominated by a sequence of tensor contractions, motivating the development of numerical libraries for such operations. While based on matrix–matrix multiplication, these libraries are specialized to exploit symmetries in the molecular structure and in electronic interactions, and thus reduce the size of the tensor representation and the complexity of contractions. The resulting algorithms are irregular and their parallelization has been previously achieved via the use of dynamic scheduling or specialized data decompositions. We introduce our efforts tomore » extend the Libtensor framework to work in the distributed memory environment in a scalable and energy-efficient manner. We achieve up to 240× speedup compared with the optimized shared memory implementation of Libtensor. We attain scalability to hundreds of thousands of compute cores on three distributed-memory architectures (Cray XC30 and XC40, and IBM Blue Gene/Q), and on a heterogeneous GPU-CPU system (Cray XK7). As the bottlenecks shift from being compute-bound DGEMM's to communication-bound collectives as the size of the molecular system scales, we adopt two radically different parallelization approaches for handling load-imbalance, tasking and bulk synchronous models. Nevertheless, we preserve a unified interface to both programming models to maintain the productivity of computational quantum chemists.« less

  12. National Transonic Facility model and model support vibration problems

    NASA Technical Reports Server (NTRS)

    Young, Clarence P., Jr.; Popernack, Thomas G., Jr.; Gloss, Blair B.

    1990-01-01

    Vibrations of models and model support system were encountered during testing in the National Transonic Facility. Model support system yaw plane vibrations have resulted in model strain gage balance design load limits being reached. These high levels of vibrations resulted in limited aerodynamic testing for several wind tunnel models. The yaw vibration problem was the subject of an intensive experimental and analytical investigation which identified the primary source of the yaw excitation and resulted in attenuation of the yaw oscillations to acceptable levels. This paper presents the principal results of analyses and experimental investigation of the yaw plane vibration problems. Also, an overview of plans for development and installation of a permanent model system dynamic and aeroelastic response measurement and monitoring system for the National Transonic Facility is presented.

  13. Critical State Finite Element Models of Contractional Fault-Related Folding: Structural and Mechanical Analyses

    NASA Astrophysics Data System (ADS)

    Albertz, M.; Lingrey, S.; Sanz, P. F.

    2011-12-01

    Geometric/kinematic models of the common fault-related fold types (fault-bend, fault-propagation, detachment folding) typically assume a simplified flexural-slip based bed-parallel simple shear mechanism. The magnitude of local strain is a function of layer dip change irrespective of material properties. Line-lengths parallel to and layer thicknesses orthogonal to the flexural-slip surface remain constant. This study reports on a range of more complicated kinematic and mechanical responses observed in fourteen idealized forward numerical models of contractional fault-related folding. The models test the effects of material properties, initial fault dip, and the presence of weak inter-layer detachment horizons. We employ a Lagrangian finite element method with adaptive remeshing and a constitutive model that is based on critical state mechanics. This approach allows for large, volumetric deformation and realistic evolution of the failure envelope during progressive deformation. We demonstrate that material properties affect the way faults propagate and thus exert a significant control on resultant fold layer geometry. In most cases, these geometries differ from the flexural-slip based kinematic idealizations. For instance, models of uniform sandstone properties exhibit efficient strain localization and clear patterns of fault tip propagation. Uniform shale properties tends to inhibit fault propagation due to distributed plastic deformation. Models with mixed inter-layered sandstone and shale deform in a disharmonic manner, resembling lobate-cuspate arrangements that are common to many outcrop-scale folds. Inter-layer detachments accommodate shortening by bed-parallel slip, resulting in fault-bend fold kinematics, imbrication of sand layers, and a general absence of fault propagation across layers. Constant area based plane strain restoration of the deformed models recovers the first-order contractional deformation (80-90% of true contractional strain). Constant line

  14. Flood Impact Modelling to support decision making

    NASA Astrophysics Data System (ADS)

    Owen, Gareth; Quinn, Paul; O'Donnell, Greg

    2015-04-01

    Much of what is known about the impacts of landuse change and Natural Flood Management (NFM) is at the local/plot scale. Evidence of the downstream impacts at the larger catchment scale is limited. However, the strategic and financial decisions of land managers, stakeholders and policy makers are made at the larger scale. There are a number of techniques that have the potential to scale local impacts to the catchment scale. This poster will show findings for the 30km2 Leven catchment, North Yorkshire, England. A NFM approach has been adopted by the Environment Agency to reduce flood risk within the catchment. A dense network of stream level gauges were installed in the catchment at the commencement of this project to gain a detailed understanding of the catchment behaviour during storm events. A novel Flood Impact Modelling (FIM) approach has been adopted which uses the network of gauges to disaggregate the outlet hydrograph in terms of source locations. Using a combination of expert opinion and local evidence, the model can be used to assess the impacts of distributed changes in land use management and NFM on flood events. A number of potential future landuse and NFM scenarios have been modelled to investigate their impact on flood peaks. These modelled outcomes are mapped to a simple Decision Support Matrix (DSM). The DSM encourages end users (e.g. land managers and policy makers) to develop an NFM scheme by studying the degree to which local runoff can be attenuated and how that flow will propagate through the network to the point of impact. The DSM relates the impact on flood peaks in terms of alterations to soil management practices and landscape flow connectivity (e.g. soil underdrainage), which can be easily understood by farmers and land managers. The DSM and the FIM together provide a simple to use and transparent modelling tool, making best use of expert knowledge, to support decision making.

  15. Finding a model that supports quality.

    PubMed

    McGregor, Margaret J

    2011-01-01

    While Canadian provinces demonstrate considerable diversity of performance within the non-profit sector and further research is needed to better understand which non-profit models support the best quality, Canadian research has been generally consistent with US research in confirming a relationship between for-profit ownership and inferior quality. The quality concerns arising from public funding to the private for-profit residential long-term care sector are unlikely to be addressed by adopting tighter regulations. With the expansion of private for-profit delivery, the organizational goals of the regulator and the facilities being regulated become less aligned. The former is likely to move to a more deterrence-based model of regulation, which is costly, less effective and draws resources away from direct patient care.

  16. On Using Model Populations to Determine Mechanical Properties of Skeletal Muscle. Application to Concentric Contraction Simulation.

    PubMed

    Sierra, M; Miana-Mena, F J; Calvo, B; Muñoz, M J; Rodríguez, J F; Grasa, J

    2015-10-01

    In the field of computational biomechanics, the experimental evaluation of the material properties is crucial for the development of computational models that closely reproduce real organ systems. When simulations of muscle tissue are concerned, stress/strain relations for both passive and active behavior are required. These experimental relations usually exhibit certain variability. In this study, a set of material parameters involved in a 3D skeletal muscle model are determined by using a system biology approach in which the parameters are randomly varied leading to a population of models. Using a set of experimental results from an animal model, a subset of the entire population of models was selected. This reduced population predicted the mechanical response within the window of experimental observations. Hence, a range of model parameters, instead of a single set of them, was determined. Rat Tibialis Anterior muscle was selected for this study. Muscles ([Formula: see text]) were activated through the sciatic nerve and during contraction the tissue pulled a weight fixed to the distal tendon (concentric contraction). Three different weights 1, 2 and 3 N were used and the time course of muscle stretch was analyzed obtaining values of (mean [Formula: see text] standard deviation): [Formula: see text], [Formula: see text] and [Formula: see text] respectively. A paired two-sided sign rank test showed significant differences between the muscle response for the three weights ([Formula: see text]). This study shows that the Monte Carlo method could be used for determine muscle characteristic parameters considering the variability of the experimental population.

  17. Cross-scale Efficient Tensor Contractions for Coupled Cluster Computations Through Multiple Programming Model Backends

    SciTech Connect

    Ibrahim, Khaled Z.; Epifanovsky, Evgeny; Williams, Samuel W.; Krylov, Anna I.

    2016-07-26

    Coupled-cluster methods provide highly accurate models of molecular structure by explicit numerical calculation of tensors representing the correlation between electrons. These calculations are dominated by a sequence of tensor contractions, motivating the development of numerical libraries for such operations. While based on matrix-matrix multiplication, these libraries are specialized to exploit symmetries in the molecular structure and in electronic interactions, and thus reduce the size of the tensor representation and the complexity of contractions. The resulting algorithms are irregular and their parallelization has been previously achieved via the use of dynamic scheduling or specialized data decompositions. We introduce our efforts to extend the Libtensor framework to work in the distributed memory environment in a scalable and energy efficient manner. We achieve up to 240 speedup compared with the best optimized shared memory implementation. We attain scalability to hundreds of thousands of compute cores on three distributed-memory architectures, (Cray XC30&XC40, BlueGene/Q), and on a heterogeneous GPU-CPU system (Cray XK7). As the bottlenecks shift from being compute-bound DGEMM's to communication-bound collectives as the size of the molecular system scales, we adopt two radically different parallelization approaches for handling load-imbalance. Nevertheless, we preserve a uni ed interface to both programming models to maintain the productivity of computational quantum chemists.

  18. Splinting Strategies to Overcome Confounding Wound Contraction in Experimental Animal Models

    PubMed Central

    Davidson, Jeffrey M.; Yu, Fang; Opalenik, Susan R.

    2013-01-01

    Significance Clinical healing by secondary intention frequently occurs in skin that is firmly anchored to underlying (human) connective tissue. Small animals (rodents) are extensively utilized to model human cutaneous wound healing, but they heal by wound contraction, a process that is limited in the human and confounds quantitative and qualitative evaluation of experimental wound repair. Recent Advances To alleviate wound contraction in loose-skinned species, practical solutions include choosing anatomical sites with firmly attached dermis and subcutis (e.g., rabbit ear) or performing mechanical fixation of the skin by using one of a number of devices or splints. In each case, the wound volume remains relatively constant, allowing the histomorphometric or biomolecular quantification of the cellular response under well-controlled, experimental conditions. In addition, the defined aperture of the splinted wound allows the placement of a variety of materials, including scaffolds, cells, and biologically active formulations into the wound site in an effort to potentiate the healing response and abrogate scarring. In contrast, production of larger experimental wounds or the deliberate distraction of wound margins can be used to model a hypertrophic response. Critical Issues Device design parameters should consider ease of application, durability, and lack of interference with the normal influx of local and circulating cells to the wound site. Future Directions Improved methods of securing flexible splints would provide a more efficient experimental platform. These devices could also incorporate optical or electronic sensors that report both the mechanical and physiological status of the healing. PMID:24527337

  19. Teaching Contracts--Present Criticism and a Model Proposal for Reform.

    ERIC Educational Resources Information Center

    Strasser, Kurt A.

    1981-01-01

    Contract teaching, it is suggested, should focus on building foundations in common law methodology and contract doctrine; the law and practice of modern commercial dispute and resolution should be a secondary goal. Criticisms of contract law and teaching of Professors Gilmore, Hurst, Friedman, Macaulay, Macneil and Reitz are reviewed. (MLW)

  20. Muscle activity and co-contraction of musculoskeletal model during steering maneuver.

    PubMed

    Gao, Zhen-hai; Fan, Da; Wang, Deping; Zhao, Hui; Zhao, Kaishu; Chen, Chaoyang

    2014-01-01

    In this study a musculoskeletal model of driver steering maneuver was established. The model was driven by the steering angle and steering torque when performing typical steering test. The simulation was calculated using inverse dynamics. Maximum muscle activity and the muscle activity of each muscle were studied afterwards. The key muscles that generated steering torque were scapular portion of deltoid, infraspinatus, latissimus dorsi, subscapularis, triceps long head and triceps lateral head. Muscle co-contraction was analyzed quantitatively and was significantly different from muscle activity. This paper presents a preliminary research on the mechanical properties of upper limb muscles during steering maneuver. The results can serve as references for vehicle design and performance evaluation using the physiological characteristics of drivers.

  1. Multiple Option Grade Contracts.

    ERIC Educational Resources Information Center

    Partin, Ronald L.

    1979-01-01

    A flexible, point contract system is described which maximizes the advantages of a criterion-referenced contract system while eliminating some of the disadvantages of standard grade contracts. This model has been used by the author in a variety of high school and college courses. (Author/SJL)

  2. Paleoclimatic modeling and phylogeography of least killifish, Heterandria formosa: insights into Pleistocene expansion-contraction dynamics and evolutionary history of North American Coastal Plain freshwater biota

    PubMed Central

    2013-01-01

    Background Climatic and sea-level fluctuations throughout the last Pleistocene glacial cycle (~130-0 ka) profoundly influenced present-day distributions and genetic diversity of Northern Hemisphere biotas by forcing range contractions in many species during the glacial advance and allowing expansion following glacial retreat ('expansion-contraction’ model). Evidence for such range dynamics and refugia in the unglaciated Gulf-Atlantic Coastal Plain stems largely from terrestrial species, and aquatic species Pleistocene responses remain relatively uninvestigated. Heterandria formosa, a wide-ranging regional endemic, presents an ideal system to test the expansion-contraction model within this biota. By integrating ecological niche modeling and phylogeography, we infer the Pleistocene history of this livebearing fish (Poeciliidae) and test for several predicted distributional and genetic effects of the last glaciation. Results Paleoclimatic models predicted range contraction to a single southwest Florida peninsula refugium during the Last Glacial Maximum, followed by northward expansion. We inferred spatial-population subdivision into four groups that reflect genetic barriers outside this refuge. Several other features of the genetic data were consistent with predictions derived from an expansion-contraction model: limited intraspecific divergence (e.g. mean mtDNA p-distance = 0.66%); a pattern of mtDNA diversity (mean Hd = 0.934; mean π = 0.007) consistent with rapid, recent population expansion; a lack of mtDNA isolation-by-distance; and clinal variation in allozyme diversity with higher diversity at lower latitudes near the predicted refugium. Statistical tests of mismatch distributions and coalescent simulations of the gene tree lent greater support to a scenario of post-glacial expansion and diversification from a single refugium than to any other model examined (e.g. multiple-refugia scenarios). Conclusions Congruent results from diverse data

  3. Nonlinear Dynamic Models in Advanced Life Support

    NASA Technical Reports Server (NTRS)

    Jones, Harry

    2002-01-01

    To facilitate analysis, ALS systems are often assumed to be linear and time invariant, but they usually have important nonlinear and dynamic aspects. Nonlinear dynamic behavior can be caused by time varying inputs, changes in system parameters, nonlinear system functions, closed loop feedback delays, and limits on buffer storage or processing rates. Dynamic models are usually cataloged according to the number of state variables. The simplest dynamic models are linear, using only integration, multiplication, addition, and subtraction of the state variables. A general linear model with only two state variables can produce all the possible dynamic behavior of linear systems with many state variables, including stability, oscillation, or exponential growth and decay. Linear systems can be described using mathematical analysis. Nonlinear dynamics can be fully explored only by computer simulations of models. Unexpected behavior is produced by simple models having only two or three state variables with simple mathematical relations between them. Closed loop feedback delays are a major source of system instability. Exceeding limits on buffer storage or processing rates forces systems to change operating mode. Different equilibrium points may be reached from different initial conditions. Instead of one stable equilibrium point, the system may have several equilibrium points, oscillate at different frequencies, or even behave chaotically, depending on the system inputs and initial conditions. The frequency spectrum of an output oscillation may contain harmonics and the sums and differences of input frequencies, but it may also contain a stable limit cycle oscillation not related to input frequencies. We must investigate the nonlinear dynamic aspects of advanced life support systems to understand and counter undesirable behavior.

  4. Empirical Performance Model-Driven Data Layout Optimization and Library Call Selection for Tensor Contraction Expressions

    SciTech Connect

    Lu, Qingda; Gao, Xiaoyang; Krishnamoorthy, Sriram; Baumgartner, Gerald; Ramanujam, J.; Sadayappan, Ponnuswamy

    2012-03-01

    Empirical optimizers like ATLAS have been very effective in optimizing computational kernels in libraries. The best choice of parameters such as tile size and degree of loop unrolling is determined by executing different versions of the computation. In contrast, optimizing compilers use a model-driven approach to program transformation. While the model-driven approach of optimizing compilers is generally orders of magnitude faster than ATLAS-like library generators, its effectiveness can be limited by the accuracy of the performance models used. In this paper, we describe an approach where a class of computations is modeled in terms of constituent operations that are empirically measured, thereby allowing modeling of the overall execution time. The performance model with empirically determined cost components is used to perform data layout optimization together with the selection of library calls and layout transformations in the context of the Tensor Contraction Engine, a compiler for a high-level domain-specific language for expressing computational models in quantum chemistry. The effectiveness of the approach is demonstrated through experimental measurements on representative computations from quantum chemistry.

  5. Global Urbanization Modeling Supported by Remote Sensing

    NASA Astrophysics Data System (ADS)

    Zhou, Y.; Smith, S.; Zhao, K.; Imhoff, M. L.; Thomson, A. M.; Bond-Lamberty, B. P.; Elvidge, C.

    2014-12-01

    Urbanization, one of the major human induced land cover and land use change, has profound impacts on the Earth system, and plays important roles in a variety of processes such as biodiversity loss, water and carbon cycle, and climate change. Accurate information on urban areas and their spatial distribution at the regional and global scales is important in both scientific and policy-making communities. The Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) nighttime stable light data (NTL) provide a potential way to map urban area and its dynamics economically and timely. In this study, we developed a cluster-based method to estimate the optimal thresholds and map urban extents from the DMSP/OLS NTL data. The sensitivity analysis demonstrates the robustness of the derived optimal thresholds and the reliability of the cluster-based method. Compared to existing threshold techniques, our method reduces the over- and under-estimation issue, when mapping urban extent over a large area. Using this cluster-based method, we built new global maps of 1-km urban extent from the NTL data (Figure 1) and evaluated its temporal dynamics from 1992 to 2013. Supported by the derived global urban maps and socio-economic drivers, we developed an integrated modeling framework by integrating a top-down macro-scale statistical model with a bottom-up urban growth model and projected future urban expansion.

  6. A Numerical Study of the Aerodynamic Interference of a Model Support System Used in the RAE 5 Metre Wind Tunnel.

    DTIC Science & Technology

    1985-09-01

    D-i65 671 A NUMERICAL STUDY OF THE AERODYNAMIC INTERFERENCEOF A 1 /1MODEL SUPPORT SYST (U) ROYAL AIRCRAFT ESTABLISHMENT FARNBOROUGH ( ENGLAND ) B C...Aircraft Establishment, Farnborough , Hants, UK 5a. Sponsoring Agency’s Code 6a. Sponsoring Agency (Contract Authority) Name and Location N/A N/A 7

  7. Eccentric Contraction-Induced Muscle Injury: Reproducible, Quantitative, Physiological Models to Impair Skeletal Muscle's Capacity to Generate Force.

    PubMed

    Call, Jarrod A; Lowe, Dawn A

    2016-01-01

    In order to investigate the molecular and cellular mechanisms of muscle regeneration an experimental injury model is required. Advantages of eccentric contraction-induced injury are that it is a controllable, reproducible, and physiologically relevant model to cause muscle injury, with injury being defined as a loss of force generating capacity. While eccentric contractions can be incorporated into conscious animal study designs such as downhill treadmill running, electrophysiological approaches to elicit eccentric contractions and examine muscle contractility, for example before and after the injurious eccentric contractions, allows researchers to circumvent common issues in determining muscle function in a conscious animal (e.g., unwillingness to participate). Herein, we describe in vitro and in vivo methods that are reliable, repeatable, and truly maximal because the muscle contractions are evoked in a controlled, quantifiable manner independent of subject motivation. Both methods can be used to initiate eccentric contraction-induced injury and are suitable for monitoring functional muscle regeneration hours to days to weeks post-injury.

  8. Stability, controllability, and observability of the "four state" model for the sarcomeric control of contraction.

    PubMed

    Yaniv, Yael; Sivan, Raphael; Landesberg, Amir

    2006-05-01

    A model of the sarcomeric control of contraction at various loading conditions has to maintain three cardinal features: stability, controllability (where the output can be controlled by the input), and observability (where the output reflects the effects of all the state variables). The suggested model of the sarcomere couples calcium kinetics with cross-bridge (XB) cycling and comprises two feedback mechanisms: (i) the cooperativity, whereby the number of force-generating (strong) XBs determines calcium affinity, regulates XB recruitment, and (ii) the mechanical feedback, whereby shortening velocity determines XBs cycling rate, controls the XBs contractile efficiency. The sarcomere is described by a set of four first-order nonlinear differential equations, utilizing the Matlab's Simulink software. Small oscillatory input was imposed when the state variables trajectories reached a steady state. The linearized state-space representations of the model were calculated for various initial sarcomere lengths. The analysis of the state-space representation validates the controllability and observability of the model. The model has four poles: three at the left side of the complex plane and one integrating pole at the origin. Therefore, the system is marginally stable. The Laplace transform confirms that the state representation is minimal and is therefore observable and controllable. The extension of the model to a multi-sarcomere lattice was explored, and the effects of inhomogeneity and nonuniform activation were described.

  9. A Computational Model Integrating Electrophysiology, Contraction, and Mitochondrial Bioenergetics in the Ventricular Myocyte

    PubMed Central

    Cortassa, Sonia; Aon, Miguel A.; O'Rourke, Brian; Jacques, Robert; Tseng, Hsiang-Jer; Marbán, Eduardo; Winslow, Raimond L.

    2006-01-01

    An intricate network of reactions is involved in matching energy supply with demand in the heart. This complexity arises because energy production both modulates and is modulated by the electrophysiological and contractile activity of the cardiac myocyte. Here, we present an integrated mathematical model of the cardiac cell that links excitation-contraction coupling with mitochondrial energy generation. The dynamics of the model are described by a system of 50 ordinary differential equations. The formulation explicitly incorporates cytoplasmic ATP-consuming processes associated with force generation and ion transport, as well as the creatine kinase reaction. Changes in the electrical and contractile activity of the myocyte are coupled to mitochondrial energetics through the ATP, Ca2+, and Na+ concentrations in the myoplasmic and mitochondrial matrix compartments. The pseudo steady-state relationship between force and oxygen consumption at various stimulus frequencies and external Ca2+ concentrations is reproduced in both model simulations and direct experiments in cardiac trabeculae under normoxic conditions, recapitulating the linearity between cardiac work and respiration in the heart. Importantly, the model can also reproduce the rapid time-dependent changes in mitochondrial NADH and Ca2+ in response to abrupt changes in workload. The steady-state and dynamic responses of the model were conferred by ADP-dependent stimulation of mitochondrial oxidative phosphorylation and Ca2+-dependent regulation of Krebs cycle dehydrogenases, illustrating how the model can be used as a tool for investigating mechanisms underlying metabolic control in the heart. PMID:16679365

  10. [Cytomechanics of oscillatory contractions. Modeling the longitudinal dynamics of Physarum polycephalum protoplasmic strands].

    PubMed

    Teplov, V A

    2010-01-01

    A mathematical model of the longitudinal dynamics of an isolated strand of the Physarum polycephalum plasmodium has been constructed. Its contractile system is considered as a continual viscoelastic medium with passive and active components. The mathematical description of the longitudinal dynamics of the plasmodial strand is reduced to a system of three first-order differential equations, whose variables are its active stress, deformation, and the intracellular concentration of calcium ions. The model is based on the hypothesis that there exists a feedback loop, which appears because of the influence of strand stretching on the rate of the release of calcium ions, which in turn controls the active contraction and deformation of the strand. Nonlinear interactions between the variables evoke a loss of the stationary state stability and a self-excitation of mechanochemical autooscillations when the external load exceeds some critical value. The results of numerical solutions of the model with the empirically determined viscoelastic parameters are in good agreement with the available experimental data and testify to the adequacy of the description of strand dynamics by the mathematical model in which the contractile apparatus is a part of the cellular control system. In particular, this model well simulates the form and duration of transient mechanochemical processes observed under isotonic and isometric conditions immediately after strand isolation, as well as the subsequent excitation of autooscillations of the contractile activity and their activation by strand stretching.

  11. Mechanisms of Excitation-Contraction Coupling in an Integrative Model of the Cardiac Ventricular Myocyte

    PubMed Central

    Greenstein, Joseph L.; Hinch, Robert; Winslow, Raimond L.

    2006-01-01

    It is now well established that characteristic properties of excitation-contraction (EC) coupling in cardiac myocytes, such as high gain and graded Ca2+ release, arise from the interactions that occur between L-type Ca2+ channels (LCCs) and nearby ryanodine-sensitive Ca2+ release channels (RyRs) in localized microdomains. Descriptions of Ca2+-induced Ca2+ release (CICR) that account for these local mechanisms are lacking from many previous models of the cardiac action potential, and those that do include local control of CICR are able to reconstruct properties of EC coupling, but require computationally demanding stochastic simulations of ∼105 individual ion channels. In this study, we generalize a recently developed analytical approach for deriving simplified mechanistic models of CICR to formulate an integrative model of the canine cardiac myocyte which is computationally efficient. The resulting model faithfully reproduces experimentally measured properties of EC coupling and whole cell phenomena. The model is used to study the role of local redundancy in L-type Ca2+ channel gating and the role of dyad configuration on EC coupling. Simulations suggest that the characteristic steep rise in EC coupling gain observed at hyperpolarized potentials is a result of increased functional coupling between LCCs and RyRs. We also demonstrate mechanisms by which alterations in the early repolarization phase of the action potential, resulting from reduction of the transient outward potassium current, alters properties of EC coupling. PMID:16214852

  12. Iterated non-linear model predictive control based on tubes and contractive constraints.

    PubMed

    Murillo, M; Sánchez, G; Giovanini, L

    2016-05-01

    This paper presents a predictive control algorithm for non-linear systems based on successive linearizations of the non-linear dynamic around a given trajectory. A linear time varying model is obtained and the non-convex constrained optimization problem is transformed into a sequence of locally convex ones. The robustness of the proposed algorithm is addressed adding a convex contractive constraint. To account for linearization errors and to obtain more accurate results an inner iteration loop is added to the algorithm. A simple methodology to obtain an outer bounding-tube for state trajectories is also presented. The convergence of the iterative process and the stability of the closed-loop system are analyzed. The simulation results show the effectiveness of the proposed algorithm in controlling a quadcopter type unmanned aerial vehicle.

  13. A Theoretical Model for Muscle Contraction based on Refractory-Activation Systems

    NASA Astrophysics Data System (ADS)

    Mitsui, Takahito; Aizawa, Yoji

    2006-03-01

    A new theoretical model for the cross-bridge formation is proporsed, and the sliding motion of the many cross-bridge system is analysed by numerical simulations in reference to the Hill's relation of the muscle contraction. In the microscopic level of each cross-bridge dynamics, both chaotic and periodic oscillations are generated though the sliding motion is smooth. In the simulated Hill's relation, the periodic oscillasion is dominant in the micro-dynamics when the sliding speed is high, but the chaotic oscillation is generally induced in the regime with the low speed. Furthermore, the maximum efficiency in chemo-mechanical energy transformation is achieved in the transition regime from the periodic to the chaotic oscillation in micro-dynamics.

  14. Simulation of dilute polymeric fluids in a three-dimensional contraction using a multiscale FENE model

    SciTech Connect

    Griebel, M. E-mail: ruettgers@ins.uni-bonn.de; Rüttgers, A. E-mail: ruettgers@ins.uni-bonn.de

    2014-05-15

    The multiscale FENE model is applied to a 3D square-square contraction flow problem. For this purpose, the stochastic Brownian configuration field method (BCF) has been coupled with our fully parallelized three-dimensional Navier-Stokes solver NaSt3DGPF. The robustness of the BCF method enables the numerical simulation of high Deborah number flows for which most macroscopic methods suffer from stability issues. The results of our simulations are compared with that of experimental measurements from literature and show a very good agreement. In particular, flow phenomena such as a strong vortex enhancement, streamline divergence and a flow inversion for highly elastic flows are reproduced. Due to their computational complexity, our simulations require massively parallel computations. Using a domain decomposition approach with MPI, the implementation achieves excellent scale-up results for up to 128 processors.

  15. Influence of joint angle on EMG-torque model during constant-posture, quasi-constant-torque contractions.

    PubMed

    Liu, Pu; Liu, Lukai; Martel, Francois; Rancourt, Denis; Clancy, Edward A

    2013-10-01

    Electromyogram (EMG)-torque modeling is of value to many different application areas, including ergonomics, clinical biomechanics and prosthesis control. One important aspect of EMG-torque modeling is the ability to account for the joint angle influence. This manuscript describes an experimental study which relates the biceps/triceps surface EMG of 12 subjects to elbow torque at seven joint angles (spanning 45-135°) during constant-posture, quasi-constant-torque contractions. Advanced EMG amplitude (EMGσ) estimation processors (i.e., whitened, multiple-channel) were investigated and three non-linear EMGσ-torque models were evaluated. When EMG-torque models were formed separately for each of the seven distinct joint angles, a minimum "gold standard" error of 4.23±2.2% MVCF90 resulted (i.e., error relative to maximum voluntary contraction at 90° flexion). This model structure, however, did not directly facilitate interpolation across angles. The best model which did so (i.e., parameterized the angle dependence), achieved an error of 4.17±1.7% MVCF90. Results demonstrated that advanced EMGσ processors lead to improved joint torque estimation. We also contrasted models that did vs. did not account for antagonist muscle co-contraction. Models that accounted for co-contraction estimated individual flexion muscle torques that were ∼29% higher and individual extension muscle torques that were ∼68% higher.

  16. A Human Ventricular Myocyte Model with a Refined Representation of Excitation-Contraction Coupling

    PubMed Central

    Himeno, Yukiko; Asakura, Keiichi; Cha, Chae Young; Memida, Hiraku; Powell, Trevor; Amano, Akira; Noma, Akinori

    2015-01-01

    Cardiac Ca2+-induced Ca2+ release (CICR) occurs by a regenerative activation of ryanodine receptors (RyRs) within each Ca2+-releasing unit, triggered by the activation of L-type Ca2+ channels (LCCs). CICR is then terminated, most probably by depletion of Ca2+ in the junctional sarcoplasmic reticulum (SR). Hinch et al. previously developed a tightly coupled LCC-RyR mathematical model, known as the Hinch model, that enables simulations to deal with a variety of functional states of whole-cell populations of a Ca2+-releasing unit using a personal computer. In this study, we developed a membrane excitation-contraction model of the human ventricular myocyte, which we call the human ventricular cell (HuVEC) model. This model is a hybrid of the most recent HuVEC models and the Hinch model. We modified the Hinch model to reproduce the regenerative activation and termination of CICR. In particular, we removed the inactivated RyR state and separated the single step of RyR activation by LCCs into triggering and regenerative steps. More importantly, we included the experimental measurement of a transient rise in Ca2+ concentrations ([Ca2+], 10–15 μM) during CICR in the vicinity of Ca2+-releasing sites, and thereby calculated the effects of the local Ca2+ gradient on CICR as well as membrane excitation. This HuVEC model successfully reconstructed both membrane excitation and key properties of CICR. The time course of CICR evoked by an action potential was accounted for by autonomous changes in an instantaneous equilibrium open probability of couplons. This autonomous time course was driven by a core feedback loop including the pivotal local [Ca2+], influenced by a time-dependent decay in the SR Ca2+ content during CICR. PMID:26200878

  17. Psychological contract breaches, organizational commitment, and innovation-related behaviors: a latent growth modeling approach.

    PubMed

    Ng, Thomas W H; Feldman, Daniel C; Lam, Simon S K

    2010-07-01

    This study examined the relationships among psychological contract breaches, organizational commitment, and innovation-related behaviors (generating, spreading, implementing innovative ideas at work) over a 6-month period. Results indicate that the effects of psychological contract breaches on employees are not static. Specifically, perceptions of psychological contract breaches strengthened over time and were associated with decreased levels of affective commitment over time. Further, increased perceptions of psychological contract breaches were associated with decreases in innovation-related behaviors. We also found evidence that organizational commitment mediates the relationship between psychological contract breaches and innovation-related behaviors. These results highlight the importance of examining the nomological network of psychological contract breaches from a change perspective.

  18. Testing nowcasts of the ionospheric convection from the expanding and contracting polar cap model

    NASA Astrophysics Data System (ADS)

    Walach, M.-T.; Milan, S. E.; Yeoman, T. K.; Hubert, B. A.; Hairston, M. R.

    2017-04-01

    The expanding/contracting polar cap (ECPC) model, or the time-dependent Dungey cycle, provides a theoretical framework for understanding solar wind-magnetosphere-ionosphere coupling. The ECPC describes the relationship between magnetopause reconnection and substorm growth phase, magnetotail reconnection and substorm expansion phase, associated changes in auroral morphology, and ionospheric convective motions. Despite the many successes of the model, there has yet to be a rigorous test of the predictions or nowcasts made regarding ionospheric convection, which remains a final hurdle for the validation of the ECPC. In this study we undertake a comparison of ionospheric convection, as measured in situ by ion drift meters on board DMSP (Defense Meteorological Satellite Program) satellites and from the ground by SuperDARN (Super Dual Auroral Radar Network), with motions nowcasted by a theoretical model. The model is coupled to measurements of changes in the size of the polar cap made using global auroral imagery from the IMAGE FUV (Imager for Magnetopause to Aurora Global Exploration Far Ultraviolet) instrument, as well as the dayside reconnection rate, estimated using the OMNI data set. The results show that we can largely nowcast the magnitudes of ionospheric convection flows using the context of our understanding of magnetic reconnection at the magnetopause and in the magnetotail.

  19. Radar Detection Models in Computer Supported Naval War Games

    DTIC Science & Technology

    1979-06-08

    Introduction ...... ................... .... 65 4.2. Machine Plotting of Radio/Radar Vertical-Plane Coverage Diagrams Model .... .............. ... 66 4.3...Theoretical Fundamentals of Radar, trans. Air Force contract AF 33(657)-164i08 (Moscow: izdatel’stvo "Sovetskoye Radion , 19641), p. 196, 18. A. G. Saybel...be run on a machine larger and faster than the WANG 2200, then this may not be a valid con- sideration. In summary, the ICETAG radar detection model

  20. Psychological contracts of hospice nurses.

    PubMed

    Jones, Audrey Elizabeth; Sambrook, Sally

    2010-12-01

    Psychological contracts have been described as individuals' beliefs regarding the obligations, expectations, and contributions that exist between them and their employer. They can be influenced by the organization's culture and philosophy, through human resources policies, and through the employee's personality and characteristics. Owing to the recent economic crisis, hospices in the UK are currently in a transitional phase and are being expected to demonstrate efficiencies that might be more in line with a business model than a health-care environment. This may conflict with the philosophical views of hospice nurses. To support nurses through this transition, it might be helpful to understand the antecedents of hospice nurses' behaviour and how they construct their psychological contracts. Failure to offer adequate support might lead to negative outcomes such as a desire to leave the organisation, poorer quality work, or disruptive behaviour. This study used a modified grounded theory approach involving in-depth interviews to explore the context and content of the psychological contracts of hospice nurses in the UK. Four main themes emerged: the types of psychological contracts formed, how the contracts are formed, their contents, and the breaches and potential violations the nurses perceive.

  1. Mutual Support: A Model of Participatory Support by and for People with Learning Difficulties

    ERIC Educational Resources Information Center

    Keyes, Sarah E.; Brandon, Toby

    2012-01-01

    Mutual Support, a model of peer support by and for people with learning difficulties, was constructed through a participatory research process. The research focussed on individual narratives from people with learning difficulties. These narratives were then brought together to form a collective model of support. This paper outlines the detailed…

  2. Mutual Support: A Model of Participatory Support by and for People with Learning Difficulties

    ERIC Educational Resources Information Center

    Keyes, Sarah E.; Brandon, Toby

    2012-01-01

    Mutual Support, a model of peer support by and for people with learning difficulties, was constructed through a participatory research process. The research focussed on individual narratives from people with learning difficulties. These narratives were then brought together to form a collective model of support. This paper outlines the detailed…

  3. Contracts for field projects and supporting research on enhanced oil recovery. Progress review No. 71, quarter ending June 30, 1992

    SciTech Connect

    Not Available

    1993-06-01

    Progress reports are presented for the following tasks: chemical flooding--supporting research; gas displacement--supporting research; thermal recovery--supporting research; geoscience technology; resource assessment technology; microbial technology; and novel technology. A list of available publication is also provided.

  4. Contracts for field projects and supporting research on enhanced oil recovery: Progress review No. 74, Quarter ending March 31, 1993

    SciTech Connect

    Not Available

    1994-03-01

    Accomplishments for the past quarter are presented for the following tasks: chemical flooding--supporting research; gas displacement--supporting research; thermal recovery--supporting research; geoscience technology; resource assessment technology; microbial technology; field demonstrations in high-priority reservoir classes; and novel technology. A list of available publication is also provided.

  5. Contracts for field projects and supporting research on enhanced oil recovery. Progress review quarter ending September 30, 1993

    SciTech Connect

    Not Available

    1994-08-01

    Progress reports are presented for the following tasks: chemical flooding--supporting research; gas displacement--supporting research; thermal recovery--supporting research; geoscience technology; resource assessment technology; and field demonstrations in high-priority reservoir classes. A list of available publications is also included.

  6. Model-based inverse estimation for active contraction stresses of tongue muscles using 3D surface shape in speech production.

    PubMed

    Koike, Narihiko; Ii, Satoshi; Yoshinaga, Tsukasa; Nozaki, Kazunori; Wada, Shigeo

    2017-09-14

    This paper presents a novel inverse estimation approach for the active contraction stresses of tongue muscles during speech. The proposed method is based on variational data assimilation using a mechanical tongue model and 3D tongue surface shapes for speech production. The mechanical tongue model considers nonlinear hyperelasticity, finite deformation, actual geometry from computed tomography (CT) images, and anisotropic active contraction by muscle fibers, the orientations of which are ideally determined using anatomical drawings. The tongue deformation is obtained by solving a stationary force-equilibrium equation using a finite element method. An inverse problem is established to find the combination of muscle contraction stresses that minimizes the Euclidean distance of the tongue surfaces between the mechanical analysis and CT results of speech production, where a signed-distance function represents the tongue surface. Our approach is validated through an ideal numerical example and extended to the real-world case of two Japanese vowels, /ʉ/ and /ɯ/. The results capture the target shape completely and provide an excellent estimation of the active contraction stresses in the ideal case, and exhibit similar tendencies as in previous observations and simulations for the actual vowel cases. The present approach can reveal the relative relationship among the muscle contraction stresses in similar utterances with different tongue shapes, and enables the investigation of the coordination of tongue muscles during speech using only the deformed tongue shape obtained from medical images. This will enhance our understanding of speech motor control. Copyright © 2017. Published by Elsevier Ltd.

  7. Modeling Flare Hard X-ray Emission from Electrons in Contracting Magnetic Islands

    NASA Astrophysics Data System (ADS)

    Guidoni, Silvina E.; Allred, Joel C.; Alaoui, Meriem; Holman, Gordon D.; DeVore, C. Richard; Karpen, Judith T.

    2016-05-01

    The mechanism that accelerates particles to the energies required to produce the observed impulsive hard X-ray emission in solar flares is not well understood. It is generally accepted that this emission is produced by a non-thermal beam of electrons that collides with the ambient ions as the beam propagates from the top of a flare loop to its footpoints. Most current models that investigate this transport assume an injected beam with an initial energy spectrum inferred from observed hard X-ray spectra, usually a power law with a low-energy cutoff. In our previous work (Guidoni et al. 2016), we proposed an analytical method to estimate particle energy gain in contracting, large-scale, 2.5-dimensional magnetic islands, based on a kinetic model by Drake et al. (2010). We applied this method to sunward-moving islands formed high in the corona during fast reconnection in a simulated eruptive flare. The overarching purpose of the present work is to test this proposed acceleration model by estimating the hard X-ray flux resulting from its predicted accelerated-particle distribution functions. To do so, we have coupled our model to a unified computational framework that simulates the propagation of an injected beam as it deposits energy and momentum along its way (Allred et al. 2015). This framework includes the effects of radiative transfer and return currents, necessary to estimate flare emission that can be compared directly to observations. We will present preliminary results of the coupling between these models.

  8. Three-dimensional mechano-electrochemical model for smooth muscle contraction of the urinary bladder.

    PubMed

    Seydewitz, Robert; Menzel, Robin; Siebert, Tobias; Böl, Markus

    2017-04-12

    The urinary bladder is a central organ of vertebrates and imposes, based on its extreme deformation (volume changes up to several 100%), special requirements on the overall bladder tissue. However, studies focusing on three-dimensional modelling of bladder deformation and bladder function during micturition are rare. Based on three fields, namely, the membrane potential, calcium concentration, and placement, a mechano-electrochemical-coupled, three-dimensional model describing the contractile behaviour of urinary bladder smooth muscle is presented using a strain energy function. The strain energy functions for the different layers of the bladder wall are additively decomposed into a passive part comprising elastin, the extracellular matrix (ECM), and collagen and an active electrochemical-driven part comprising the contraction of smooth muscle cells (SMC). While the two-variable FitzHugh-Nagumo-type membrane model (FitzHugh, 1961; Nagumo et al., 1962) has been used to describe the membrane potential characteristics, the four-state, cross-bridge model of Hai and Murphy (1988) is implemented into the finite element method for the quantification of the calcium phase. Appropriate model parameters were determined experimentally using 40 tissue strips isolated from porcine bladders. Characteristic orientation-dependent passive and active stress-stretch relationships were identified for muscle strips, including the entire bladder wall structure and those featuring the isolated muscle layer only. Active experiments on the smooth muscle layers revealed higher stresses in the longitudinal (28.9kPa) direction than in the transversal (22.7kPa) one. Additionally, three-dimensional deformation characteristics were recorded from single muscle strips to qualitatively confirm the strip simulations. Three-dimensional simulations at the tissue strip level and the organ level were performed to analyse the interaction among the electrical action potential, calcium distribution

  9. Modelled present and future thaw lake area expansion/contraction trends throughout the continuous permafrost zone

    NASA Astrophysics Data System (ADS)

    Mi, Y.; van Huissteden, J.; Dolman, A. J.

    2014-07-01

    Thaw lakes and drained lake basins are a dominant feature of Arctic lowlands. Thaw lakes are a source of the greenhouse gas methane (CH4), which is produced under anaerobic conditions, while drained lake basins are carbon sinks due to sedimentation. Besides feedbacks on climate, the development of thaw lakes due to the melt-out of ground ice and subsequent ground subsidence, can have significant impacts on the regional morphology, hydrology, geophysics and biogehemistry. Permafrost degradation as a result of climate warming, which is proceeding considerably faster in high latitude regions than the global average, could lead to either an increases in lake area due to lake expansion, or decrease due to lake drainage. However, which process will dominate is elusive. Therefore understanding thaw lake dynamics and quantifying the feedbacks related to thaw lake expansion and contraction are urgent questions to solve. We apply a stochastic model, THAWLAKE, on four representative Arctic sites, to reproduce recent lake dynamics (1963-2012) and predict for the future changes under various anticipated climate scenarios. The model simulations of current thaw lake cycles and expansion rates are comparable with data. Future lake expansions are limited by lake drainage. We suggest further improvements in the area of enhancing the hydrology component, and operation on larger scales to gauge the impacts on lacustrine morphology and greenhouse gas emissions.

  10. Model 5514 Capsize Experiments Representing the Pre-Contract DDG51 Hull Form at End of Service Life Conditions

    DTIC Science & Technology

    2006-04-01

    in Storm Sea State 8 - Hurricane Camille, Fn=0.3 ................... 68 v ABSTRACT The DDG51 pre-contract hull form as represented by Model 5514 was...15 M odel V elocity and Propeller Shaft Speed... State 8 - Hurricane Camille ............... 46 34. Plot of Significant Single Amplitude Pitch in Sea State 8 - Hurricane Camille ............... 47 35

  11. The Support Model for Interactive Assessment

    ERIC Educational Resources Information Center

    Ahmed, Ayesha; Pollitt, Alastair

    2010-01-01

    The two most common models for assessment involve measuring "how well" students perform on a task (the "quality model"), and "how difficult" a task students can succeed on (the "difficulty model"). By exploiting the interactive potential of computers we may be able to use a third model: measuring "how…

  12. Superfund Contract Laboratory Program

    EPA Pesticide Factsheets

    The Contract Laboratory Program (CLP) is a national network of EPA personnel, commercial laboratories, and support contractors whose primary mission is to provide data of known and documented quality to the Superfund program.

  13. Contracting Deployment Customer Guide.

    DTIC Science & Technology

    1996-12-01

    functional managers from the major commands expressed the need to develop a Customer Guide for contingency deployments which would standardize, simplify, and...streamline the support our Contingency Contracting Officers (CCOs) provide to our customers .

  14. Implementation of Contraction to Electrophysiological Ventricular Myocyte Models, and Their Quantitative Characterization via Post-Extrasystolic Potentiation.

    PubMed

    Ji, Yanyan Claire; Gray, Richard A; Fenton, Flavio H

    2015-01-01

    Heart failure (HF) affects over 5 million Americans and is characterized by impairment of cellular cardiac contractile function resulting in reduced ejection fraction in patients. Electrical stimulation such as cardiac resynchronization therapy (CRT) and cardiac contractility modulation (CCM) have shown some success in treating patients with HF. Computer simulations have the potential to help improve such therapy (e.g. suggest optimal lead placement) as well as provide insight into the underlying mechanisms which could be beneficial. However, these myocyte models require a quantitatively accurate excitation-contraction coupling such that the electrical and contraction predictions are correct. While currently there are close to a hundred models describing the detailed electrophysiology of cardiac cells, the majority of cell models do not include the equations to reproduce contractile force or they have been added ad hoc. Here we present a systematic methodology to couple first generation contraction models into electrophysiological models via intracellular calcium and then compare the resulting model predictions to experimental data. This is done by using a post-extrasystolic pacing protocol, which captures essential dynamics of contractile forces. We found that modeling the dynamic intracellular calcium buffers is necessary in order to reproduce the experimental data. Furthermore, we demonstrate that in models the mechanism of the post-extrasystolic potentiation is highly dependent on the calcium released from the Sarcoplasmic Reticulum. Overall this study provides new insights into both specific and general determinants of cellular contractile force and provides a framework for incorporating contraction into electrophysiological models, both of which will be necessary to develop reliable simulations to optimize electrical therapies for HF.

  15. Implementation of Contraction to Electrophysiological Ventricular Myocyte Models, and Their Quantitative Characterization via Post-Extrasystolic Potentiation

    PubMed Central

    Ji, Yanyan Claire; Gray, Richard A.; Fenton, Flavio H.

    2015-01-01

    Heart failure (HF) affects over 5 million Americans and is characterized by impairment of cellular cardiac contractile function resulting in reduced ejection fraction in patients. Electrical stimulation such as cardiac resynchronization therapy (CRT) and cardiac contractility modulation (CCM) have shown some success in treating patients with HF. Computer simulations have the potential to help improve such therapy (e.g. suggest optimal lead placement) as well as provide insight into the underlying mechanisms which could be beneficial. However, these myocyte models require a quantitatively accurate excitation-contraction coupling such that the electrical and contraction predictions are correct. While currently there are close to a hundred models describing the detailed electrophysiology of cardiac cells, the majority of cell models do not include the equations to reproduce contractile force or they have been added ad hoc. Here we present a systematic methodology to couple first generation contraction models into electrophysiological models via intracellular calcium and then compare the resulting model predictions to experimental data. This is done by using a post-extrasystolic pacing protocol, which captures essential dynamics of contractile forces. We found that modeling the dynamic intracellular calcium buffers is necessary in order to reproduce the experimental data. Furthermore, we demonstrate that in models the mechanism of the post-extrasystolic potentiation is highly dependent on the calcium released from the Sarcoplasmic Reticulum. Overall this study provides new insights into both specific and general determinants of cellular contractile force and provides a framework for incorporating contraction into electrophysiological models, both of which will be necessary to develop reliable simulations to optimize electrical therapies for HF. PMID:26317204

  16. Three-dimensional model for aerosol transport and deposition in expanding and contracting alveoli.

    PubMed

    Balásházy, Imre; Hofmann, Werner; Farkas, Arpád; Madas, Balázs G

    2008-04-01

    Particle transport and deposition within a model alveolus, represented by a rhythmically expanding and contracting hemisphere, was modeled by a three-dimensional analytical model for the time-dependent air velocity field as a superposition of uniform and radial flow components, satisfying both the mass and momentum conservation equations. Trajectories of particles entrained in the airflow were calculated by a numerical particle trajectory code to compute simultaneously deposition by inertial impaction, gravitational sedimentation, Brownian diffusion, and interception. Five different orientations of the orifice of the alveolus relative to the direction of gravity were selected. Deposition was calculated for particles from 1 nm to 10 microm, for 3 breathing conditions, and for 5 different entrance times relative to the onset of inspiration. For the analyzed cases, the spatial orientation of the orifice of an alveolus has practically no effect on deposition for particles below about 0.1 microm, where deposition is dominated by Brownian motion. Above about 1 microm, where deposition is governed primarily by gravitational settling, deposition can vary from 0 to 100%, depending on the spatial orientation, while deposition of particles 0.1-1 microm falls between these two extreme cases. Due to the isotropic nature of Brownian motion, deposition of the 10-nm particles is practically uniform for all spatial orientations. However, for larger particles, deposition can be quite inhomogeneous, consistent with the direction of gravity. While nearly all particles are exhaled during the successive expiration phase, there are a few cases where particles still leave the alveolus even after many breathing cycles.

  17. Support Center for Regulatory Atmospheric Modeling (SCRAM)

    EPA Pesticide Factsheets

    This technical site provides access to air quality models (including computer code, input data, and model processors) and other mathematical simulation techniques used in assessing air emissions control strategies and source impacts.

  18. Influence of Joint Angle on EMG-Torque Model During Constant-Posture, Torque-Varying Contractions.

    PubMed

    Liu, Pu; Liu, Lukai; Clancy, Edward A

    2015-11-01

    Relating the electromyogram (EMG) to joint torque is useful in various application areas, including prosthesis control, ergonomics and clinical biomechanics. Limited study has related EMG to torque across varied joint angles, particularly when subjects performed force-varying contractions or when optimized modeling methods were utilized. We related the biceps-triceps surface EMG of 22 subjects to elbow torque at six joint angles (spanning 60° to 135°) during constant-posture, torque-varying contractions. Three nonlinear EMG σ -torque models, advanced EMG amplitude (EMG σ ) estimation processors (i.e., whitened, multiple-channel) and the duration of data used to train models were investigated. When EMG-torque models were formed separately for each of the six distinct joint angles, a minimum "gold standard" error of 4.01±1.2% MVC(F90) resulted (i.e., error relative to maximum voluntary contraction at 90° flexion). This model structure, however, did not directly facilitate interpolation across angles. The best model which did so achieved a statistically equivalent error of 4.06±1.2% MVC(F90). Results demonstrated that advanced EMG σ processors lead to improved joint torque estimation as do longer model training durations.

  19. Supporting Students' Knowledge Transfer in Modeling Activities

    ERIC Educational Resources Information Center

    Piksööt, Jaanika; Sarapuu, Tago

    2014-01-01

    This study investigates ways to enhance secondary school students' knowledge transfer in complex science domains by implementing question prompts. Two samples of students applied two web-based models to study molecular genetics--the model of genetic code (n = 258) and translation (n = 245). For each model, the samples were randomly divided into…

  20. Supporting Students' Knowledge Transfer in Modeling Activities

    ERIC Educational Resources Information Center

    Piksööt, Jaanika; Sarapuu, Tago

    2014-01-01

    This study investigates ways to enhance secondary school students' knowledge transfer in complex science domains by implementing question prompts. Two samples of students applied two web-based models to study molecular genetics--the model of genetic code (n = 258) and translation (n = 245). For each model, the samples were randomly divided into…

  1. Vocational Resource Educator: A Support Service Model.

    ERIC Educational Resources Information Center

    Stephens, Charlotte

    The Vocational Resource Educator (VRE) coordinates the activities of all handicapped students of DeSoto County School District in Mississippi and provides vocational assessment to all handicapped students who enroll in a vocational program. Vocational support personnel assess students' interests, abilities, and special needs so they can…

  2. Modeling uncertainty in requirements engineering decision support

    NASA Technical Reports Server (NTRS)

    Feather, Martin S.; Maynard-Zhang, Pedrito; Kiper, James D.

    2005-01-01

    One inherent characteristic of requrements engineering is a lack of certainty during this early phase of a project. Nevertheless, decisions about requirements must be made in spite of this uncertainty. Here we describe the context in which we are exploring this, and some initial work to support elicitation of uncertain requirements, and to deal with the combination of such information from multiple stakeholders.

  3. Using Technology to Support the Army Learning Model

    DTIC Science & Technology

    2016-02-01

    Research Report 1990 Using Technology to Support the Army Learning Model Joanne Barnieu Ray Morath Jonathan Bryson...COVERED (From - To) November 2013 – July 2015 4. TITLE AND SUBTITLE Using Technology to Support the Army Learning Model 5a... Learning Model (ALM; TRADOC PAM 525-8-2). The findings provide TRADOC with insights of the facilitating and limiting factors that potentially affected

  4. Rhode Island Model Evaluation & Support System: Teacher. Edition III

    ERIC Educational Resources Information Center

    Rhode Island Department of Education, 2015

    2015-01-01

    Rhode Island educators believe that implementing a fair, accurate, and meaningful educator evaluation and support system will help improve teaching and learning. The primary purpose of the Rhode Island Model Teacher Evaluation and Support System (Rhode Island Model) is to help all teachers improve. Through the Model, the goal is to help create a…

  5. Consequences of intravascular lymphatic valve properties: a study of contraction timing in a multi-lymphangion model.

    PubMed

    Bertram, Christopher D; Macaskill, Charlie; Davis, Michael J; Moore, James E

    2016-04-01

    The observed properties of valves in collecting lymphatic vessels include transmural pressure-dependent bias to the open state and hysteresis. The bias may reduce resistance to flow when the vessel is functioning as a conduit. However, lymphatic pumping implies a streamwise increase in mean pressure across each valve, suggesting that the bias is then potentially unhelpful. Lymph pumping by a model of several collecting lymphatic vessel segments (lymphangions) in series, which incorporated these properties, was investigated under conditions of adverse pressure difference while varying the refractory period between active muscular contractions and the inter-lymphangion contraction delay. It was found that many combinations of the timing parameters and the adverse pressure difference led to one or more intermediate valves remaining open instead of switching between open and closed states during repetitive contraction cycles. Cyclic valve switching was reliably indicated if the mean pressure in a lymphangion over a cycle was higher than that in the lymphangion upstream, but either lack of or very brief valve closure could cause mean pressure to be lower downstream. Widely separated combinations of refractory period and delay time were found to produce the greatest flow-rate for a given pressure difference. The efficiency of pumping was always maximized by a long refractory period and lymphangion contraction starting when the contraction of the lymphangion immediately upstream was peaking. By means of an ex vivo experiment, it was verified that intermediate valves in a chain of pumping lymphangions can remain open, while the lymphangions on either side of the open valve continue to execute contractions.

  6. Future Contracting for Availability

    DTIC Science & Technology

    2016-04-30

    performance-based logistics efforts, logistics technology development, logistics human capital development, and cross-corporate logistics business...Service Contracting (OBSC). Under the outcomes based model , a customer (Defense) contracts and pays for business results delivered by a service...provider (industry), rather than for defined activities, tasks, or assets . These types of contracts focus on the outcomes rather than piece parts or the

  7. Exposure to Radiofrequency Radiation Emitted from Common Mobile Phone Jammers Alters the Pattern of Muscle Contractions: an Animal Model Study.

    PubMed

    Rafati, A; Rahimi, S; Talebi, A; Soleimani, A; Haghani, M; Mortazavi, S M J

    2015-09-01

    The rapid growth of wireless communication technologies has caused public concerns regarding the biological effects of electromagnetic radiations on human health. Some early reports indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians such as the alterations of the pattern of muscle extractions. This study is aimed at investigating the effects of exposure to radiofrequency (RF) radiation emitted from mobile phone jammers on the pulse height of contractions, the time interval between two subsequent contractions and the latency period of frog's isolated gastrocnemius muscle after stimulation with single square pulses of 1V (1 Hz). Frogs were kept in plastic containers in a room. Animals in the jammer group were exposed to radiofrequency (RF) radiation emitted from a common Jammer at a distance of 1m from the jammer's antenna for 2 hours while the control frogs were only sham exposed. Then animals were sacrificed and isolated gastrocnemius muscles were exposed to on/off jammer radiation for 3 subsequent 10 minute intervals. Isolated gastrocnemius muscles were attached to the force transducer with a string. Using a PowerLab device (26-T), the pattern of muscular contractions was monitored after applying single square pulses of 1V (1 Hz) as stimuli. The findings of this study showed that the pulse height of muscle contractions could not be affected by the exposure to electromagnetic fields. However, the latency period was effectively altered in RF-exposed samples. However, none of the experiments could show an alteration in the time interval between two subsequent contractions after exposure to electromagnetic fields. These findings support early reports which indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians including the effects on the pattern of muscle extractions.

  8. Exposure to Radiofrequency Radiation Emitted from Common Mobile Phone Jammers Alters the Pattern of Muscle Contractions: an Animal Model Study

    PubMed Central

    Rafati, A.; Rahimi, S.; Talebi, A.; Soleimani, A.; Haghani, M.; Mortazavi, S. M. J.

    2015-01-01

    Introduction The rapid growth of wireless communication technologies has caused public concerns regarding the biological effects of electromagnetic radiations on human health. Some early reports indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians such as the alterations of the pattern of muscle extractions. This study is aimed at investigating the effects of exposure to radiofrequency (RF) radiation emitted from mobile phone jammers on the pulse height of contractions, the time interval between two subsequent contractions and the latency period of frog’s isolated gastrocnemius muscle after stimulation with single square pulses of 1V (1 Hz). Materials and Methods Frogs were kept in plastic containers in a room. Animals in the jammer group were exposed to radiofrequency (RF) radiation emitted from a common Jammer at a distance of 1m from the jammer’s antenna for 2 hours while the control frogs were only sham exposed. Then animals were sacrificed and isolated gastrocnemius muscles were exposed to on/off jammer radiation for 3 subsequent 10 minute intervals. Isolated gastrocnemius muscles were attached to the force transducer with a string. Using a PowerLab device (26-T), the pattern of muscular contractions was monitored after applying single square pulses of 1V (1 Hz) as stimuli. Results The findings of this study showed that the pulse height of muscle contractions could not be affected by the exposure to electromagnetic fields. However, the latency period was effectively altered in RF-exposed samples. However, none of the experiments could show an alteration in the time interval between two subsequent contractions after exposure to electromagnetic fields. Conclusion These findings support early reports which indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians including the effects on the pattern of muscle extractions. PMID:26396969

  9. Business models for health care decision support.

    PubMed

    Gaughan, Phil

    2003-01-01

    CareScience, Inc. is a public company (NASDAQ: CARE) that originated ten years ago to commercialize risk adjustment and complication predictions developed by the Wharton School of Business and the University of Pennsylvania School of Medicine. Over the past decade, the company has grown to approximately 200 clients and 150 employees. Among the "firsts" recorded by the company, CareScience was the first to offer a clinical decision support system as an Application Service Provider (ASP), the first to offer peer-to-peer clinical data sharing among health care provider organizations and practitioners (Santa Barbara Care Data Exchange), and the first to provide a care management outsourcing arrangement.

  10. Predictive analytics can support the ACO model.

    PubMed

    Bradley, Paul

    2012-04-01

    Predictive analytics can be used to rapidly spot hard-to-identify opportunities to better manage care--a key tool in accountable care. When considering analytics models, healthcare providers should: Make value-based care a priority and act on information from analytics models. Create a road map that includes achievable steps, rather than major endeavors. Set long-term expectations and recognize that the effectiveness of an analytics program takes time, unlike revenue cycle initiatives that may show a quick return.

  11. Issues in physician contracting.

    PubMed

    Fanburg, John D; Leone, Alyson M

    2005-09-01

    Dermatologists will enter into a number of different contracts during their professional careers. It is important that in each agreement they enter, dermatologists reap the benefits that they aspire for and understand the consequences of each provision. This article addresses just a few of the different issues that arise in physician contracting, such as choosing the appropriate form of business entity; the importance of a writing; term and termination of the contract; compensation models; benefits, vacation and other time off included in the contract; malpractice insurance; and restrictive covenants. Each provision should be carefully analyzed to ensure that it will protect the best interests of the dermatologist in that situation.

  12. Autologous Graft Thickness Affects Scar Contraction and Quality in a Porcine Excisional Wound Model

    PubMed Central

    Rose, Lloyd F.; Wu, Jesse C.; Tucker, David I.; Chan, Maren M.; Christy, Robert J.; Hale, Robert G.; Leung, Kai P.

    2015-01-01

    Background: Texture, color, and durability are important characteristics to consider for skin replacement in conspicuous and/or mobile regions of the body such as the face, neck, and hands. Although autograft thickness is a known determinant of skin quality, few studies have correlated the subjective and objective characters of skin graft healing with their associated morphologic and cellular profiles. Defining these relationships may help guide development and evaluation of future skin replacement strategies. Methods: Six-centimeter-diameter full-thickness wounds were created on the back of female Yorkshire pigs and covered by autografts of variable thicknesses. Skin quality was assessed on day 120 using an observer scar assessment score and objective determinations for scar contraction, erythema, pigmentation, and surface irregularities. Histological, histochemical, and immunohistochemical assessments were performed. Results: Thick grafts demonstrated lower observer scar assessment score (better quality) and decreased erythema, pigmentation, and surface irregularities. Histologically, thin grafts resulted in scar-like collagen proliferation while thick grafts preserves the dermal architecture. Increased vascularity and prolonged and increased cellular infiltration were observed among thin grafts. In addition, thin grafts contained predominately dense collagen fibers, whereas thick grafts had loosely arranged collagen. α-Smooth muscle actin staining for myofibroblasts was observed earlier and persisted longer among thinner grafts. Conclusions: Graft thickness is an important determinant of skin quality. High-quality skin replacements are associated with preserved collagen architecture, decreased neovascularization, and decreased inflammatory cellular infiltration. This model, using autologous skin as a metric of quality, may give a more informative analysis of emerging skin replacement strategies. PMID:26301157

  13. Integration/coordination contractor support to Environmental Restoration Program and Program Support Office. Contract status report, September 1, 1995--September 30, 1995

    SciTech Connect

    1995-10-01

    This status report updates activities on the following tasks: Environmental restoration task planning; Waste management task planning; Waste management project support; CPP stakeholder involvement; EM site specific advisory board - Idaho National Engineering Laboratory; and, Hypermedia document. A summary status assessment and forecast of all tasks is provided and A cost management report is included.

  14. Airborne SAR imagery to support hydraulic models

    NASA Astrophysics Data System (ADS)

    Castiglioni, S.

    2009-04-01

    Satellite images and airborne SAR (Synthetic Aperture Radar) imagery are increasingly widespread and they are effective tools for measuring the size of flood events and for assessment of damage. The Hurricane Katrina disaster and the tsunami catastrophe in Indian Ocean countries are two recent and sadly famous examples. Moreover, as well known, the inundation maps can be used as tools to calibrate and validate hydraulic model (e.g. Horritt et al., Hydrological Processes, 2007). We carry out an application of a 1D hydraulic model coupled with a high resolution DTM for predicting the flood inundation processes. The study area is a 16 km reach of the River Severn, in west-central England, for which, four maps of inundated areas, obtained through airborne SAR images, and hydrometric data are available. The inundation maps are used for the calibration/validation of a 1D hydraulic model through a comparison between airborne SAR images and the results of hydraulic simulations. The results confirm the usefulness of inundation maps as hydraulic modelling tools and, moreover, show that 1D hydraulic model can be effectively used when coupled with high resolution topographic information.

  15. PM Signals Warfare Contract Opportunities

    DTIC Science & Technology

    2002-05-06

    06MAY2002 - 07MAY2002 Title and Subtitle PM Signals Warfare Contract Opportunities Contract Number Grant Number Program Element Number Author(s...The Future” • Full ISR Wartime Capability • Support OOTW, Counter Narcotic, and Emergency /Natural Disaster Operations • FLIR, IRLS, DIS, MTI/SAR and...ACS Contract Opportunities 3/29/02 Aerial Common Sensor • Objective: Develop, Produce, and Field the Army’s Objective ISR System • Contract Type: CAD

  16. Controlled Ecological Life Support System (CELSS) modeling

    NASA Technical Reports Server (NTRS)

    Drysdale, Alan; Thomas, Mark; Fresa, Mark; Wheeler, Ray

    1992-01-01

    Attention is given to CELSS, a critical technology for the Space Exploration Initiative. OCAM (object-oriented CELSS analysis and modeling) models carbon, hydrogen, and oxygen recycling. Multiple crops and plant types can be simulated. Resource recovery options from inedible biomass include leaching, enzyme treatment, aerobic digestion, and mushroom and fish growth. The benefit of using many small crops overlapping in time, instead of a single large crop, is demonstrated. Unanticipated results include startup transients which reduce the benefit of multiple small crops. The relative contributions of mass, energy, and manpower to system cost are analyzed in order to determine appropriate research directions.

  17. Strategies to Support Students' Mathematical Modeling

    ERIC Educational Resources Information Center

    Jung, Hyunyi

    2015-01-01

    An important question for mathematics teachers is this: "How can we help students learn mathematics to solve everyday problems, rather than teaching them only to memorize rules and practice mathematical procedures?" Teaching students using modeling activities can help them learn mathematics in real-world problem-solving situations that…

  18. Decision Support System for Resource Allocation Model

    DTIC Science & Technology

    1989-04-01

    by Presutti and Trepp in their paper "Much Ado about EOQ." [2) The constraints used in the stock fund model are total stock fund dollars and limits on...Jersey, 1963. 2. Presutti, Victor J., Jr. and Trepp , Richard C., More Ado About Economic Order Ouantities (EOO), Operations Analysis Office

  19. Strategies to Support Students' Mathematical Modeling

    ERIC Educational Resources Information Center

    Jung, Hyunyi

    2015-01-01

    An important question for mathematics teachers is this: "How can we help students learn mathematics to solve everyday problems, rather than teaching them only to memorize rules and practice mathematical procedures?" Teaching students using modeling activities can help them learn mathematics in real-world problem-solving situations that…

  20. Using Covariation Reasoning to Support Mathematical Modeling

    ERIC Educational Resources Information Center

    Jacobson, Erik

    2014-01-01

    For many students, making connections between mathematical ideas and the real world is one of the most intriguing and rewarding aspects of the study of mathematics. In the Common Core State Standards for Mathematics (CCSSI 2010), mathematical modeling is highlighted as a mathematical practice standard for all grades. To engage in mathematical…

  1. Rhode Island Model Evaluation & Support System: Building Administrator. Edition III

    ERIC Educational Resources Information Center

    Rhode Island Department of Education, 2015

    2015-01-01

    Rhode Island educators believe that implementing a fair, accurate, and meaningful educator evaluation and support system will help improve teaching, learning, and school leadership. The primary purpose of the Rhode Island Model Building Administrator Evaluation and Support System (Rhode Island Model) is to help all building administrators improve.…

  2. Key Elements of the Tutorial Support Management Model

    ERIC Educational Resources Information Center

    Lynch, Grace; Paasuke, Philip

    2011-01-01

    In response to an exponential growth in enrolments the "Tutorial Support Management" (TSM) model has been adopted by Open Universities Australia (OUA) after a two-year project on the provision of online tutor support in first year, online undergraduate units. The essential focus of the TSM model was the development of a systemic approach…

  3. Key Elements of the Tutorial Support Management Model

    ERIC Educational Resources Information Center

    Lynch, Grace; Paasuke, Philip

    2011-01-01

    In response to an exponential growth in enrolments the "Tutorial Support Management" (TSM) model has been adopted by Open Universities Australia (OUA) after a two-year project on the provision of online tutor support in first year, online undergraduate units. The essential focus of the TSM model was the development of a systemic approach…

  4. Kinetic modeling of the assembly, dynamic steady state, and contraction of the FtsZ ring in prokaryotic cytokinesis.

    PubMed

    Surovtsev, Ivan V; Morgan, Jeffrey J; Lindahl, Paul A

    2008-07-04

    Cytokinesis in prokaryotes involves the assembly of a polymeric ring composed of FtsZ protein monomeric units. The Z ring forms at the division plane and is attached to the membrane. After assembly, it maintains a stable yet dynamic steady state. Once induced, the ring contracts and the membrane constricts. In this work, we present a computational deterministic biochemical model exhibiting this behavior. The model is based on biochemical features of FtsZ known from in vitro studies, and it quantitatively reproduces relevant in vitro data. An essential part of the model is a consideration of interfacial reactions involving the cytosol volume, where monomeric FtsZ is dispersed, and the membrane surface in the cell's mid-zone where the ring is assembled. This approach allows the same chemical model to simulate either in vitro or in vivo conditions by adjusting only two geometrical parameters. The model includes minimal reactions, components, and assumptions, yet is able to reproduce sought-after in vivo behavior, including the rapid assembly of the ring via FtsZ-polymerization, the formation of a dynamic steady state in which GTP hydrolysis leads to the exchange of monomeric subunits between cytoplasm and the ring, and finally the induced contraction of the ring. The model gives a quantitative estimate for coupling between the rate of GTP hydrolysis and of FtsZ subunit turnover between the assembled ring and the cytoplasmic pool as observed. Membrane constriction is chemically driven by the strong tendency of GTP-bound FtsZ to self-assembly. The model suggests a possible mechanism of membrane contraction without a motor protein. The portion of the free energy of GTP hydrolysis released in cyclization is indirectly used in this energetically unfavorable process. The model provides a limit to the mechanistic complexity required to mimic ring behavior, and it highlights the importance of parallel in vitro and in vivo modeling.

  5. Dengue human infection models supporting drug development.

    PubMed

    Whitehorn, James; Van, Vinh Chau Nguyen; Simmons, Cameron P

    2014-06-15

    Dengue is a arboviral infection that represents a major global health burden. There is an unmet need for effective dengue therapeutics to reduce symptoms, duration of illness and incidence of severe complications. Here, we consider the merits of a dengue human infection model (DHIM) for drug development. A DHIM could allow experimentally controlled studies of candidate therapeutics in preselected susceptible volunteers, potentially using smaller sample sizes than trials that recruited patients with dengue in an endemic country. In addition, the DHIM would assist the conduct of intensive pharmacokinetic and basic research investigations and aid in determining optimal drug dosage. Furthermore, a DHIM could help establish proof of concept that chemoprophylaxis against dengue is feasible. The key challenge in developing the DHIM for drug development is to ensure the model reliably replicates the typical clinical and laboratory features of naturally acquired, symptomatic dengue. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

  6. DOD Oversight Improvements are Needed on the Contractor Accounting System for the Army’s Cost-Reimbursable Stryker Logistics Support Contract

    DTIC Science & Technology

    2013-07-16

    Policy FAR Federal Acquisition Regulation GDLS General Dynamics Land System PCO Procuring Contracting Officer PEO Program Executive Officer...our March 2012 preliminary briefing of the accounting system deficiencies, PMO Stryker issued a procuring contracting officer ( PCO ) letter that...and such a billing practice must be corrected. Specifically, the PCO letter, dated March 7, 2012, stated: This PCO [procuring contracting officer

  7. Statistical modeling to support power system planning

    NASA Astrophysics Data System (ADS)

    Staid, Andrea

    This dissertation focuses on data-analytic approaches that improve our understanding of power system applications to promote better decision-making. It tackles issues of risk analysis, uncertainty management, resource estimation, and the impacts of climate change. Tools of data mining and statistical modeling are used to bring new insight to a variety of complex problems facing today's power system. The overarching goal of this research is to improve the understanding of the power system risk environment for improved operation, investment, and planning decisions. The first chapter introduces some challenges faced in planning for a sustainable power system. Chapter 2 analyzes the driving factors behind the disparity in wind energy investments among states with a goal of determining the impact that state-level policies have on incentivizing wind energy. Findings show that policy differences do not explain the disparities; physical and geographical factors are more important. Chapter 3 extends conventional wind forecasting to a risk-based focus of predicting maximum wind speeds, which are dangerous for offshore operations. Statistical models are presented that issue probabilistic predictions for the highest wind speed expected in a three-hour interval. These models achieve a high degree of accuracy and their use can improve safety and reliability in practice. Chapter 4 examines the challenges of wind power estimation for onshore wind farms. Several methods for wind power resource assessment are compared, and the weaknesses of the Jensen model are demonstrated. For two onshore farms, statistical models outperform other methods, even when very little information is known about the wind farm. Lastly, chapter 5 focuses on the power system more broadly in the context of the risks expected from tropical cyclones in a changing climate. Risks to U.S. power system infrastructure are simulated under different scenarios of tropical cyclone behavior that may result from climate

  8. Decision-Support Quantitative Models for Valuing Incentives in Performance Based Contracts

    DTIC Science & Technology

    2005-06-01

    arresting hook captures one of the cables and the arresting gear caliper brakes decelerate the AV to a stop within 15m...arresting hook mounted on the underside of the AV and ground-based pendant cables attached to an arresting brake at each end. After landing, the

  9. Georeferenced model simulations efficiently support targeted monitoring

    NASA Astrophysics Data System (ADS)

    Berlekamp, Jürgen; Klasmeier, Jörg

    2010-05-01

    The European Water Framework Directive (WFD) demands the good ecological and chemical status of surface waters. To meet the definition of good chemical status of the WFD surface water concentrations of priority pollutants must not exceed established environmental quality standards (EQS). Surveillance of the concentrations of numerous chemical pollutants in whole river basins by monitoring is laborious and time-consuming. Moreover, measured data do often not allow for immediate source apportionment which is a prerequisite for defining promising reduction strategies to be implemented within the programme of measures. In this context, spatially explicit model approaches are highly advantageous because they provide a direct link between local point emissions (e.g. treated wastewater) or diffuse non-point emissions (e.g. agricultural runoff) and resulting surface water concentrations. Scenario analyses with such models allow for a priori investigation of potential positive effects of reduction measures such as optimization of wastewater treatment. The geo-referenced model GREAT-ER (Geography-referenced Regional Exposure Assessment Tool for European Rivers) has been designed to calculate spatially resolved averaged concentrations for different flow conditions (e.g. mean or low flow) based on emission estimations for local point source emissions such as treated effluents from wastewater treatment plants. The methodology was applied to selected pharmaceuticals (diclofenac, sotalol, metoprolol, carbamazepin) in the Main river basin in Germany (approx. 27,290 km²). Average concentrations of the compounds were calculated for each river reach in the whole catchment. Simulation results were evaluated by comparison with available data from orienting monitoring and used to develop an optimal monitoring strategy for the assessment of water quality regarding micropollutants at the catchment scale.

  10. What Model Should Be Used to Evaluate the Efficiency and Effectiveness of a Field Contracting Office

    DTIC Science & Technology

    2003-06-01

    Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188) Washington DC 20503. 1...CONTRACT MANAGEMENT from the NAVAL POSTGRADUATE SCHOOL June 2003 Author: Daniel O’Sullivan Approved by: Jeffrey R. Cuskey Thesis...9 B. LITERATURE REVIEW ON EFFICIENCY AND EFFECTIVENESS IN PERFORMANCE MANAGEMENT ...................11 C. ORGANIZATIONAL

  11. A Simple, Inexpensive Model to Demonstrate How Contraction of GI Longitudinal Smooth Muscle Promotes Propulsion

    ERIC Educational Resources Information Center

    Lujan, Heidi L.; DiCarlo, Stephen E.

    2015-01-01

    Peristalis is a propulsive activity that involves both circular and longitudinal muscle layers of the esophagus, distal stomach, and small and large intestines. During peristalsis, the circular smooth muscle contracts behind (on the orad side) the bolus and relaxes in front (on the aborad side) of the bolus. At the same time, the longitudinal…

  12. State Assessment Program Item Banks: Model Language for Request for Proposals (RFP) and Contracts

    ERIC Educational Resources Information Center

    Swanson, Leonard C.

    2010-01-01

    This document provides recommendations for request for proposal (RFP) and contract language that state education agencies can use to specify their requirements for access to test item banks. An item bank is a repository for test items and data about those items. Item banks are used by state agency staff to view items and associated data; to…

  13. A Simple, Inexpensive Model to Demonstrate How Contraction of GI Longitudinal Smooth Muscle Promotes Propulsion

    ERIC Educational Resources Information Center

    Lujan, Heidi L.; DiCarlo, Stephen E.

    2015-01-01

    Peristalis is a propulsive activity that involves both circular and longitudinal muscle layers of the esophagus, distal stomach, and small and large intestines. During peristalsis, the circular smooth muscle contracts behind (on the orad side) the bolus and relaxes in front (on the aborad side) of the bolus. At the same time, the longitudinal…

  14. Knowledge Modelling to Support Inquiry Learning Tasks

    NASA Astrophysics Data System (ADS)

    Wolff, Annika; Mulholland, Paul; Zdrahal, Zdenek; Blasko, Miroslav

    In this paper we describe the SILVER toolkit, which is designed for tasks in which a user learns by analysing and interpreting a set of resources. The user categorises each resource according to the set of properties that they identify as being applicable to it. Due to the large amount of data generated by this type of task, the user may find it hard to identify patterns in their classification and tagging, to recognise their own inconsistencies or make comparisons between themselves and others. In the first SILVER task described, the ID3 decision tree algorithm is applied to the user's data to identify patterns and generate different types of feedback. Principles of spatial hypertext are used to produce an interactive visualization of the summarized data. As the user interacts with the resources, they can see their progress and changing perspective on the task. In the second SILVER task described, a conceptual model is used to provide explanations of the model underlying the user's classification of resources.

  15. Digital Terrain Data in Support of Land Combat Models

    DTIC Science & Technology

    1988-09-01

    LI : " : ! US A r Cors of Engineers OC 1 4 988.. CDD DIGITAL TERRAIN DATA IN SUPPORT OF LAND COvBAT MODELS I CENTER - The views, opinions, and/or...NO. CCESSION NO. 0 0 0 11. TITLE (Include Security Classification) (U) Digital Terrain Data in Support of Land Combat Models 12. PERSONAL AUTHOR(S...identify by block number) FIELD GROUP SUB-GROUP Engineers, Wargame Simulation, Model Development, Data Base, Digital Terrain, Mapping, Geographic

  16. Supportive Accountability: A Model for Providing Human Support to Enhance Adherence to eHealth Interventions

    PubMed Central

    2011-01-01

    The effectiveness of and adherence to eHealth interventions is enhanced by human support. However, human support has largely not been manualized and has usually not been guided by clear models. The objective of this paper is to develop a clear theoretical model, based on relevant empirical literature, that can guide research into human support components of eHealth interventions. A review of the literature revealed little relevant information from clinical sciences. Applicable literature was drawn primarily from organizational psychology, motivation theory, and computer-mediated communication (CMC) research. We have developed a model, referred to as “Supportive Accountability.” We argue that human support increases adherence through accountability to a coach who is seen as trustworthy, benevolent, and having expertise. Accountability should involve clear, process-oriented expectations that the patient is involved in determining. Reciprocity in the relationship, through which the patient derives clear benefits, should be explicit. The effect of accountability may be moderated by patient motivation. The more intrinsically motivated patients are, the less support they likely require. The process of support is also mediated by the communications medium (eg, telephone, instant messaging, email). Different communications media each have their own potential benefits and disadvantages. We discuss the specific components of accountability, motivation, and CMC medium in detail. The proposed model is a first step toward understanding how human support enhances adherence to eHealth interventions. Each component of the proposed model is a testable hypothesis. As we develop viable human support models, these should be manualized to facilitate dissemination. PMID:21393123

  17. An Experimental Model Using Cultured Cardiac Myocytes for a Study of the Generation of Premature Ventricular Contractions Under Ultrasound Exposure

    NASA Astrophysics Data System (ADS)

    Kudo, Nobuki; Yamamoto, Masaya

    2011-09-01

    It is known that use of a contrast agents in echocardiography increases the probability of generation of premature ventricular contractions (PVCs). As a basic study to elucidate the mechanisms and to reduce adverse effects, the generation of PVCs was investigated using cultured cardiac myocytes instead of the intact heart in vivo. Cardiac myocytes were isolated from neonatal rats and cultured on a cover slip. The myocyte sample was exposed to pulsed ultrasound with microbubbles adjacent to the myocytes, and generation of PVCs was examined with ultrasound exposure at various delay times after onset of myocyte contraction. The experimental results showed that generation of PVCs had a stable threshold delay time and that PVCs were generated only when myocytes were exposed to ultrasound with delay times longer than the threshold. The results indicate that the model used in this study is useful for revealing the mechanisms by which PVCs are induced by ultrasound exposure.

  18. A model for effective planning of SME support services.

    PubMed

    Rakićević, Zoran; Omerbegović-Bijelović, Jasmina; Lečić-Cvetković, Danica

    2016-02-01

    This paper presents a model for effective planning of support services for small and medium-sized enterprises (SMEs). The idea is to scrutinize and measure the suitability of support services in order to give recommendations for the improvement of a support planning process. We examined the applied support services and matched them with the problems and needs of SMEs, based on the survey conducted in 2013 on a sample of 336 SMEs in Serbia. We defined and analysed the five research questions that refer to support services, their consistency with the SMEs' problems and needs, and the relation between the given support and SMEs' success. The survey results have shown a statistically significant connection between them. Based on this result, we proposed an eight-phase model as a method for the improvement of support service planning for SMEs. This model helps SMEs to plan better their requirements in terms of support; government and administration bodies at all levels and organizations that provide support services to understand better SMEs' problems and needs for support. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Architect's Contract.

    ERIC Educational Resources Information Center

    Ohio State Board of Education, Columbus.

    An actual contract form used for architectural services is presented. Fees, duties, and services are included. Services are listed in the following phases--(1) schematic design, (2) design development, (3) contract document, and (4) construction. Extra services are listed, and owner's responsibility with regard to cost estimates is given.…

  20. Distension-Induced Gastric Contraction is Attenuated in an Experimental Model of Gastric Restraint

    PubMed Central

    Lu, Xiao; Guo, Xiaomei; Mattar, Samer G.; Navia, Jose A.

    2010-01-01

    Background Gastric distension has important implications for motility and satiety. The hypothesis of this study was that distension affects the amplitude and duration of gastric contraction and that these parameters are largely mediated by efferent vagus stimulation. Methods A novel isovolumic myograph was introduced to test these hypotheses. The isovolumic myograph isolates the stomach and records the pressure generated by the gastric contraction under isovolumic conditions. Accordingly, the phasic changes of gastric contractility can be documented. A group of 12 rats were used under in vivo conditions and isolated ex vivo conditions and with two different gastric restraints (small and large) to determine the effect of degree of restraint. Results The comparison of the in vivo and ex vivo contractility provided information on the efferent vagus mediation of gastric contraction, i.e., the in vivo amplitude and duration reached maximum of 12.6 ± 2.7 mmHg and 19.8 ± 5.6 s in contrast to maximum of 5.7 ± 0.9 mmHg and 7.3 ± 1.3 s in ex vivo amplitude and duration, respectively. The comparison of gastric restraint and control groups highlights the role of distension on in vivo gastric contractility. The limitation of gastric distension by restraint drastically reduced the maximal amplitude to below 2.9 ± 0.2 mmHg. Conclusions The results show that distension-induced gastric contractility is regulated by both central nervous system and local mechanisms with the former being more substantial. Furthermore, the gastric restraint significantly attenuates gastric contractility (decreased amplitude and shortened duration of contraction) which is mediated by the efferent vagus activation. These findings have important implications for gastric motility and physiology and may improve our understanding of satiety. PMID:20706803

  1. 48 CFR 842.101 - Contract audit responsibilities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract audit... CONTRACT MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Contract Audit Services 842.101 Contract audit responsibilities. (a) Contracting officers may use the support services of other agencies to...

  2. Health, Supportive Environments, and the Reasonable Person Model

    Treesearch

    Stephen Kaplan; Rachel Kaplan

    2003-01-01

    The Reasonable Person Model is a conceptual framework that links environmental factors with human behavior. People are more reasonable, cooperative, helpful, and satisfied when the environment supports their basic informational needs. The same environmental supports are important factors in enhancing human health. We use this framework to identify the informational...

  3. [Barriers to the normalization of telemedicine in a healthcare system model based on purchasing of healthcare services using providers' contracts].

    PubMed

    Roig, Francesc; Saigí, Francesc

    2011-01-01

    Despite the clear political will to promote telemedicine and the large number of initiatives, the incorporation of this modality in clinical practice remains limited. The objective of this study was to identify the barriers perceived by key professionals who actively participate in the design and implementation of telemedicine in a healthcare system model based on purchasing of healthcare services using providers' contracts. We performed a qualitative study based on data from semi-structured interviews with 17 key informants belonging to distinct Catalan health organizations. The barriers identified were grouped in four areas: technological, organizational, human and economic. The main barriers identified were changes in the healthcare model caused by telemedicine, problems with strategic alignment, resistance to change in the (re)definition of roles, responsibilities and new skills, and lack of a business model that incorporates telemedicine in the services portfolio to ensure its sustainability. In addition to suitable management of change and of the necessary strategic alignment, the definitive normalization of telemedicine in a mixed healthcare model based on purchasing of healthcare services using providers' contracts requires a clear and stable business model that incorporates this modality in the services portfolio and allows healthcare organizations to obtain reimbursement from the payer. 2010 SESPAS. Published by Elsevier Espana. All rights reserved.

  4. Contracts for field projects and supporting research on enhanced oil recovery. Progress review No. 80. Quarterly report, July--September, 1994

    SciTech Connect

    1995-11-01

    This report contains information on petroleum enhanced recovery projects. In addition to project descriptions, contract numbers, principal investigators and project management information is included.

  5. Choice of contracts in the British National Health Service: an empirical study.

    PubMed

    Chalkley, Martin; McVicar, Duncan

    2008-09-01

    Following major reforms of the British National Health Service (NHS) in 1990, the roles of purchasing and providing health services were separated, with the relationship between purchasers and providers governed by contracts. Using a mixed multinomial logit analysis, we show how this policy shift led to a selection of contracts that is consistent with the predictions of a simple model, based on contract theory, in which the characteristics of the health services being purchased and of the contracting parties influence the choice of contract form. The paper thus provides evidence in support of the practical relevance of theory in understanding health care market reform.

  6. An in vitro rat model of colonic motility to determine the effect of β-casomorphin-5 on propagating contractions.

    PubMed

    Dalziel, J E; Spencer, N J; Dunstan, K E; Lynch, A T; Haggarty, N W; Gopal, P K; Roy, N C

    2014-11-01

    Beta-casomorphin-5 (βCM-5) is a milk-derived bioactive peptide that slows gastro-intestinal transit (GIT) in vivo and blocks the peristaltic reflex in the guinea pig colon in vitro. We wanted to establish an in vitro model system in which effects of dairy-derived substances containing opioid peptides on intestinal motility can be assessed and used to predict in vivo outcomes. Because βCM-5 is an opioid agonist that acts on enteric neurons, we used this substance to compare two different isolated colonic tissue preparations to determine which would more closely mimic the in vivo response previously reported in the literature. We compared and characterized the effects of βCM-5 on spontaneous contractions in isolated segments of distal colon (1 cm length) compared with propagating contractions along the isolated intact large intestine (22 cm length). In short segments of distal colon, βCM-5 increased the tension and frequency of spontaneous contractions in a concentration-dependent manner. At 20 μM βCM-5 tension increased by 71 ± 17% and the frequency doubled (n = 9), effects inhibited by naloxone (n = 7) and therefore mediated by opioid receptors. In contrast 20 μM βCM-5 disrupted propagating contractions in the large intestine preparation. At 20 μM βCM-5 reduced the proportion of contractions initiated in the proximal colon reaching the rectum by 83 ± 11% (n = 5) and this effect was also inhibited by naloxone, consistent with altered GIT reported in vivo. Our results demonstrate that the isolated whole large intestine provides an ideal preparation that mimics the reduced propagation of GIT in vivo in response to an opioid agonist, whereas short colon segments did not. The findings of the current study reveal that preserving large segments of intact large intestine, and hence intact enteric neural circuitry provides an ideal in vitro model to investigate the effect of opioid receptor modulators on intestinal transit.

  7. A Framework and Model for Evaluating Clinical Decision Support Architectures

    PubMed Central

    Wright, Adam; Sittig, Dean F.

    2008-01-01

    In this paper, we develop a four-phase model for evaluating architectures for clinical decision support that focuses on: defining a set of desirable features for a decision support architecture; building a proof-of-concept prototype; demonstrating that the architecture is useful by showing that it can be integrated with existing decision support systems and comparing its coverage to that of other architectures. We apply this framework to several well-known decision support architectures, including Arden Syntax, GLIF, SEBASTIAN and SAGE PMID:18462999

  8. Application of a Process Model to a Management Support System.

    DTIC Science & Technology

    The concept of a process model is developed and used as a basis for data organization for use in a Management Support System (MSS). The data...organization is proposed as being useful for historical records that constitute the bulk of the information stored in an MSS. The concept of a process model , and...manager. Other uses of the proposed data organization are also considered. Extensions of the process model are considered by combining the model with

  9. How does Vorticella utilize its stalk contraction-relaxation cycle?

    NASA Astrophysics Data System (ADS)

    Zhou, Jiazhong; Admiraal, David; Ryu, Sangjin

    2015-03-01

    Vorticella is a sessile ciliate living in water, and it coils its slender stalk to pull the cell body (zooid) towards the substrate at a maximum speed of ~ 1 cm/s. After stalk contraction is completed, the stalk slowly relaxes to its extended state. Although this ultrafast stalk contraction has been studied in terms of cell motility, it is poorly understood how Vorticella utilizes its stalk contraction. Here we propose a hypothesis that Vorticella can augment transport of particles near the substrate relying on water flow induced by the stalk contraction-relaxation cycle. We investigated our hypothesis using a computational fluid dynamics (CFD) model which models Vorticella as a solid sphere moving normal to a solid surface in water. Having simulated water flow caused by Vorticella, we calculated motions of particles near Vorticella, and then quantified the transport effect of Vorticella's stalk contraction using microfluidic mixing indices. Supported by Laymann Seed grant from UNL.

  10. Strong Metal-Support Interactions (smsi) in Model Titania-Supported Rhodium Catalysts.

    NASA Astrophysics Data System (ADS)

    Sadeghi, Hassan Roger

    Model catalysts consisting of rhodium particles supported on well characterized, single crystal rutile substrates were used to study the nature of strong metal -support interactions (SMSI) in supported catalyst systems. The use of single crystal supports eliminates many of the complications inherent with powder supported catalysts and greatly simplifies the interpretation of experimental data. A variety of surface sensitive electron spectroscopic techniques, including ultraviolet and x-ray photoemission (UPS and XPS), electron energy loss (ELS) and Auger spectroscopies, low energy electron diffraction (LEED), combined with chemisorption measurements were applied to rhodium on titania model catalysts in order to separate the various phenomena that contribute to SMSI. The properties of the clean titania supports have been determined, including the dynamics of oxidation of reduced surfaces. Model catalysts were then prepared by thermal evaporation of rhodium onto these supports. The high temperature reduction procedures that produce the SMSI state on powder supported catalysts have been used on the model catalysts, and Auger sputter profiles indicate that during high temperature reduction (HTR) a suboxide of titanium migrates onto the rhodium particles, thus blocking carbon monoxide chemisorption. Removal of the suboxide layer by ion bombardment restores the normal chemisorption properties of the catalyst. Model rhodium on titania catalysts fabricated on both fully oxidized and on partially reduced single crystal supports have also been used. In this way it is possible to observe support-to-metal charge transfer in the absence of the encapsulation that accompanies HTR. The experimental results show that reduced titania species and rhodium interact with each other through a partially ionic bond, with electronic charge transferred from the reduced titanium cations to the rhodium. This bonding interaction is part of the driving force that leads to encapsulation of the

  11. Human Exposure Modeling - Databases to Support Exposure Modeling

    EPA Pesticide Factsheets

    Human exposure modeling relates pollutant concentrations in the larger environmental media to pollutant concentrations in the immediate exposure media. The models described here are available on other EPA websites.

  12. Checking software contracts

    SciTech Connect

    Mitchell, R.; Maung, I.; Howse, J.; Heathcote, T.

    1995-12-31

    In object-oriented software, contracts between classes can be expressed in terms of preconditions, postconditions and invariants. In the programming language Eiffel, contracts can be checked at run-time. Within inheritance hierarchies, contracts can be used to control the redefinition of services. In Eiffel, the rules ensure that redefinition is safe in the presence of polymorphism and dynamic binding. This paper shows that Eiffel`s support for contracts can be extended, both to cover the polymorphic case more fully, and to cover other uses of inheritance, including its use for selectively reusing code from a parent class. The paper proposes that software designers should state what properties they claim for any uses of inheritance, in order that extra checks on consistency can be applied, and shows that some extra debugging power could be obtained easily, by changing only the run-time system for Eiffel, rather than the language itself.

  13. Support System Effects on the NASA Common Research Model

    NASA Technical Reports Server (NTRS)

    Rivers, S. Melissa B.; Hunter, Craig A.

    2012-01-01

    An experimental investigation of the NASA Common Research Model was conducted in the NASA Langley National Transonic Facility and NASA Ames 11-Foot Transonic Wind Tunnel Facility for use in the Drag Prediction Workshop. As data from the experimental investigations was collected, a large difference in moment values was seen between the experimental and the computational data from the 4th Drag Prediction Workshop. This difference led to the present work. In this study, a computational assessment has been undertaken to investigate model support system interference effects on the Common Research Model. The configurations computed during this investigation were the wing/body/tail=0deg without the support system and the wing/body/tail=0deg with the support system. The results from this investigation confirm that the addition of the support system to the computational cases does shift the pitching moment in the direction of the experimental results.

  14. Alterations in Nerve-Evoked Bladder Contractions in a Coronavirus-Induced Mouse Model of Multiple Sclerosis

    PubMed Central

    Malykhina, Anna P.; Barbe, Mary F.; Ruggieri, Michael R.

    2014-01-01

    Background Patients with neurodegenerative diseases such as multiple sclerosis, Parkinson’s, and Alzheimer’s often present with lower urinary tract symptoms (LUTS, urinary frequency, urgency, nocturia and retention) resulting from damage to the peripheral and central nervous systems. These studies were designed to examine the changes in the function of the bladder that may underlie neurogenic bladder dysfunction using a mouse model of demyelination in the CNS. Methods Bladders from 12 week old male C57BL/6J mice with coronavirus-induced encephalomyelitis (CIE, a chronic, progressive demyelinating disease model of human MS), and age-matched controls, were cut into 5–7 strips and suspended in physiological muscle baths for tension measurement in response to agonists and electric field stimulation (EFS). Experiments were performed on intact and denuded (with mucosa removed) bladder strips. Results The maximum effect of EFS was not significantly different between CIE and control bladders. Nerve-evoked EFS contractions (tetrodotoxin-sensitive) were blocked by a combination of atropine (cholinergic antagonist) and α,β-methylene ATP (an ATP analog that desensitizes purinergic receptors). In response to EFS, the α,β-methylene ATP-resistant (cholinergic) component of contraction was significantly reduced, while the atropine-resistant (purinergic) component was significantly increased in CIE bladders. Removal of the mucosa in CIE bladders restored the cholinergic component. Bethanechol (muscarinic receptor agonist) potency was significantly increased in CIE bladders. Conclusions Our data demonstrate a deficit in the nerve-evoked cholinergic component of contraction that is not due to the ability of the smooth muscle to respond to acetylcholine. We conclude that neurodegenerative bladder dysfunction in this model of multiple sclerosis may be due, in part, to pathologic changes in the mucosa that causes suppression of muscarinic receptor-mediated contractile response

  15. Alterations in nerve-evoked bladder contractions in a coronavirus-induced mouse model of multiple sclerosis.

    PubMed

    Lamarre, Neil S; Braverman, Alan S; Malykhina, Anna P; Barbe, Mary F; Ruggieri, Michael R

    2014-01-01

    Patients with neurodegenerative diseases such as multiple sclerosis, Parkinson's, and Alzheimer's often present with lower urinary tract symptoms (LUTS, urinary frequency, urgency, nocturia and retention) resulting from damage to the peripheral and central nervous systems. These studies were designed to examine the changes in the function of the bladder that may underlie neurogenic bladder dysfunction using a mouse model of demyelination in the CNS. Bladders from 12 week old male C57BL/6J mice with coronavirus-induced encephalomyelitis (CIE, a chronic, progressive demyelinating disease model of human MS), and age-matched controls, were cut into 5-7 strips and suspended in physiological muscle baths for tension measurement in response to agonists and electric field stimulation (EFS). Experiments were performed on intact and denuded (with mucosa removed) bladder strips. The maximum effect of EFS was not significantly different between CIE and control bladders. Nerve-evoked EFS contractions (tetrodotoxin-sensitive) were blocked by a combination of atropine (cholinergic antagonist) and α,β-methylene ATP (an ATP analog that desensitizes purinergic receptors). In response to EFS, the α,β-methylene ATP-resistant (cholinergic) component of contraction was significantly reduced, while the atropine-resistant (purinergic) component was significantly increased in CIE bladders. Removal of the mucosa in CIE bladders restored the cholinergic component. Bethanechol (muscarinic receptor agonist) potency was significantly increased in CIE bladders. Our data demonstrate a deficit in the nerve-evoked cholinergic component of contraction that is not due to the ability of the smooth muscle to respond to acetylcholine. We conclude that neurodegenerative bladder dysfunction in this model of multiple sclerosis may be due, in part, to pathologic changes in the mucosa that causes suppression of muscarinic receptor-mediated contractile response and augmentation of purinergic response of

  16. Where neuroscience and dynamic system theory meet autonomous robotics: a contracting basal ganglia model for action selection.

    PubMed

    Girard, B; Tabareau, N; Pham, Q C; Berthoz, A; Slotine, J-J

    2008-05-01

    Action selection, the problem of choosing what to do next, is central to any autonomous agent architecture. We use here a multi-disciplinary approach at the convergence of neuroscience, dynamical system theory and autonomous robotics, in order to propose an efficient action selection mechanism based on a new model of the basal ganglia. We first describe new developments of contraction theory regarding locally projected dynamical systems. We exploit these results to design a stable computational model of the cortico-baso-thalamo-cortical loops. Based on recent anatomical data, we include usually neglected neural projections, which participate in performing accurate selection. Finally, the efficiency of this model as an autonomous robot action selection mechanism is assessed in a standard survival task. The model exhibits valuable dithering avoidance and energy-saving properties, when compared with a simple if-then-else decision rule.

  17. Competing for Contract Support Services

    DTIC Science & Technology

    1979-12-01

    integrity, fairness, objectivity, and absence of bias or favoritism in the procurement process. Zemansky is a strong advocate of competition for...architectural, engineering and consulting firms that render professional services. In discussing the pro’s and cons of comnetitive procurement, Zemansky developed...contractors, overpayment for shoddy products or "kick backs" (,1 :5]. Zemansky concludes that, without delving into a detailed analysis of numerous

  18. Activities of the Oil Implementation Task Force, reporting period March--August 1991; Contracts for field projects and supporting research on enhanced oil recovery, reporting period October--December 1990

    SciTech Connect

    Not Available

    1991-10-01

    Activities of DOE's Oil Implementation Task Force for the period March--August 1991 are reviewed. Contracts for fields projects and supporting research on enhanced oil recovery are discussed, with a list of related publications given. Enhanced recovery processes covered include chemical flooding, gas displacement, thermal recovery, and microbial recovery.

  19. Reviewing model application to support animal health decision making.

    PubMed

    Singer, Alexander; Salman, Mo; Thulke, Hans-Hermann

    2011-04-01

    Animal health is of societal importance as it affects human welfare, and anthropogenic interests shape decision making to assure animal health. Scientific advice to support decision making is manifold. Modelling, as one piece of the scientific toolbox, is appreciated for its ability to describe and structure data, to give insight in complex processes and to predict future outcome. In this paper we study the application of scientific modelling to support practical animal health decisions. We reviewed the 35 animal health related scientific opinions adopted by the Animal Health and Animal Welfare Panel of the European Food Safety Authority (EFSA). Thirteen of these documents were based on the application of models. The review took two viewpoints, the decision maker's need and the modeller's approach. In the reviewed material three types of modelling questions were addressed by four specific model types. The correspondence between tasks and models underpinned the importance of the modelling question in triggering the modelling approach. End point quantifications were the dominating request from decision makers, implying that prediction of risk is a major need. However, due to knowledge gaps corresponding modelling studies often shed away from providing exact numbers. Instead, comparative scenario analyses were performed, furthering the understanding of the decision problem and effects of alternative management options. In conclusion, the most adequate scientific support for decision making - including available modelling capacity - might be expected if the required advice is clearly stated.

  20. A Generic Modeling Process to Support Functional Fault Model Development

    NASA Technical Reports Server (NTRS)

    Maul, William A.; Hemminger, Joseph A.; Oostdyk, Rebecca; Bis, Rachael A.

    2016-01-01

    Functional fault models (FFMs) are qualitative representations of a system's failure space that are used to provide a diagnostic of the modeled system. An FFM simulates the failure effect propagation paths within a system between failure modes and observation points. These models contain a significant amount of information about the system including the design, operation and off nominal behavior. The development and verification of the models can be costly in both time and resources. In addition, models depicting similar components can be distinct, both in appearance and function, when created individually, because there are numerous ways of representing the failure space within each component. Generic application of FFMs has the advantages of software code reuse: reduction of time and resources in both development and verification, and a standard set of component models from which future system models can be generated with common appearance and diagnostic performance. This paper outlines the motivation to develop a generic modeling process for FFMs at the component level and the effort to implement that process through modeling conventions and a software tool. The implementation of this generic modeling process within a fault isolation demonstration for NASA's Advanced Ground System Maintenance (AGSM) Integrated Health Management (IHM) project is presented and the impact discussed.

  1. Interrogative Model of Inquiry and Computer-Supported Collaborative Learning.

    ERIC Educational Resources Information Center

    Hakkarainen, Kai; Sintonen, Matti

    2002-01-01

    Examines how the Interrogative Model of Inquiry (I-Model), developed for the purposes of epistemology and philosophy of science, could be applied to analyze elementary school students' process of inquiry in computer-supported learning. Suggests that the interrogative approach to inquiry can be productively applied for conceptualizing inquiry in…

  2. Three-dimensional surface geometries of the rabbit soleus muscle during contraction: input for biomechanical modelling and its validation.

    PubMed

    Böl, Markus; Leichsenring, Kay; Weichert, Christine; Sturmat, Maike; Schenk, Philipp; Blickhan, Reinhard; Siebert, Tobias

    2013-11-01

    There exists several numerical approaches to describe the active contractile behaviour of skeletal muscles. These models range from simple one-dimensional to more advanced three-dimensional ones; especially, three-dimensional models take up the cause of describing complex contraction modes in a realistic way. However, the validation of such concepts is challenging, as the combination of geometry, material and force characteristics is so far not available from the same muscle. To this end, we present in this study a comprehensive data set of the rabbit soleus muscle consisting of the muscles' characteristic force responses (active and passive), its three-dimensional shape during isometric, isotonic and isokinetic contraction experiments including the spatial arrangement of muscle tissue and aponeurosis-tendon complex, and the fascicle orientation throughout the whole muscle at its optimal length. In this way, an extensive data set is available giving insight into the three-dimensional geometry of the rabbit soleus muscle and, further, allowing to validate three-dimensional numerical models.

  3. Final Report DOE Supported Activities through the Utility/DOE Matching Grant Program Contract Number DE FG02-95NE38111 For the Period 30 September 1995 through 30 September 2002 Extended until 30 March 2003

    SciTech Connect

    Stubbins, James F.

    2003-08-15

    This report covers activities in the Univesity of Illinois Department of Nulcear, Plasma and Radiological Engineering Matching Grant Program for the period form 30 September 1995 to 30 March 2003. The funds for this program include industrial partner funds which were matched, or nearly matched by DOE-NE. The industrial partner was Commonwealth Edison, which changed its corporate structure and name to Exelon during the course of the contract. The funds from the contract were used to support nuclear engineering educational needs, including undergraduate and graduate students support, purchase of laboratory equipment, support for seminar speakers and conferences, and support for new faculty members. The funds were instrumental in maintaining a first quality nuclear engineering educational program at the University of Illinois.

  4. Lengthening-contractions in isolated myocardium impact force development and worsen cardiac contractile function in the mdx mouse model of muscular dystrophy.

    PubMed

    Xu, Ying; Delfín, Dawn A; Rafael-Fortney, Jill A; Janssen, Paul M L

    2011-02-01

    Lengthening-contractions exert eccentric stress on myofibers in normal myocardium. In congestive heart failure caused by a variety of diseases, the impact of lengthening-contractions of myocardium likely becomes more prevalent and severe. The present study introduces a method to investigate the role of stretching imposed by repetitive lengthening-contractions in myocardium under near-physiological conditions. By exerting various stretch-release ramps while the muscle is contracting, consecutive lengthening-contractions and their potential detrimental effect on cardiac function can be studied. We tested our model and hypothesis in age-matched (young and adult) mdx and wild-type mouse right ventricular trabeculae. These linear and ultrathin muscles possess all major cardiac cell types, and their contractile behavior very closely mimics that of the whole myocardium. In the first group of experiments, 10 lengthening-contractions at various magnitudes of stretch were performed in trabeculae from 10-wk-old mdx and wild-type mice. In the second group, 100 lengthening-contractions at various magnitudes were conducted in trabeculae from 10- and 20-wk-old mice. The peak isometric active developed tension (F(dev), in mN/mm(2)) and kinetic parameters time to peak tension (TTP, in ms) and time from peak tension to half-relaxation (RT50, in ms) were measured. Our results indicate lengthening-contractions significantly impact contractile behavior, and that dystrophin-deficient myocardium in mdx mice is significantly more susceptible to these damaging lengthening-contractions. The results indicate that lengthening-contractions in intact myocardium can be used in vitro to study this emerging contributor to cardiomyopathy.

  5. Mechanics of Vorticella contraction.

    PubMed

    Misra, Gaurav; Dickinson, Richard B; Ladd, Anthony J C

    2010-06-16

    Vorticella convallaria is one of a class of fast-moving organisms that can traverse its body size in less than a millisecond by rapidly coiling a slender stalk anchoring it to a nearby surface. The stalk houses a fiber called the spasmoneme, which winds helically within the stalk and rapidly contracts in response to calcium signaling. We have developed a coupled mechanical-chemical model of the coiling process, accounting for the coiling of the elastic stalk and the binding of calcium to the protein spasmin. Simulations of the model describe the contraction and recovery processes quantitatively. The stalk-spasmoneme system is shown to satisfy geometric constraints, which explains why the cell body sometimes rotates during contraction. The shape of the collapsing and recovering stalk bounds its effective bending stiffness. Simulations suggest that recovery from the contracted state is driven by the stalk at a rate controlled by dissociation of calcium from spasmin.

  6. Mechanics of Vorticella Contraction

    PubMed Central

    Misra, Gaurav; Dickinson, Richard B.; Ladd, Anthony J.C.

    2010-01-01

    Abstract Vorticella convallaria is one of a class of fast-moving organisms that can traverse its body size in less than a millisecond by rapidly coiling a slender stalk anchoring it to a nearby surface. The stalk houses a fiber called the spasmoneme, which winds helically within the stalk and rapidly contracts in response to calcium signaling. We have developed a coupled mechanical-chemical model of the coiling process, accounting for the coiling of the elastic stalk and the binding of calcium to the protein spasmin. Simulations of the model describe the contraction and recovery processes quantitatively. The stalk-spasmoneme system is shown to satisfy geometric constraints, which explains why the cell body sometimes rotates during contraction. The shape of the collapsing and recovering stalk bounds its effective bending stiffness. Simulations suggest that recovery from the contracted state is driven by the stalk at a rate controlled by dissociation of calcium from spasmin. PMID:20550905

  7. Decision Process Models of Contractor Behavior: The Development of Effective Contract Incentives. Multi-Project Decision Process Model.

    DTIC Science & Technology

    1981-04-01

    the cash flows, significant cost overruns and the resultant impacl: on the financial position of the firm. If the quarterly performance is... financial liability resulting from production inefficiencies and/or inaccurate cost estimation. The contract type which corresponds most directly to... financial liability associated with this uncertainty entirely upon the contractor. Further- more, the DOD has been, generally speaking, unwilling to pay a

  8. Prioritization of engineering support requests and advanced technology projects using decision support and industrial engineering models

    NASA Technical Reports Server (NTRS)

    Tavana, Madjid

    1995-01-01

    The evaluation and prioritization of Engineering Support Requests (ESR's) is a particularly difficult task at the Kennedy Space Center (KSC) -- Shuttle Project Engineering Office. This difficulty is due to the complexities inherent in the evaluation process and the lack of structured information. The evaluation process must consider a multitude of relevant pieces of information concerning Safety, Supportability, O&M Cost Savings, Process Enhancement, Reliability, and Implementation. Various analytical and normative models developed over the past have helped decision makers at KSC utilize large volumes of information in the evaluation of ESR's. The purpose of this project is to build on the existing methodologies and develop a multiple criteria decision support system that captures the decision maker's beliefs through a series of sequential, rational, and analytical processes. The model utilizes the Analytic Hierarchy Process (AHP), subjective probabilities, the entropy concept, and Maximize Agreement Heuristic (MAH) to enhance the decision maker's intuition in evaluating a set of ESR's.

  9. Operations and support cost modeling of conceptual space vehicles

    NASA Technical Reports Server (NTRS)

    Ebeling, Charles

    1994-01-01

    The University of Dayton is pleased to submit this annual report to the National Aeronautics and Space Administration (NASA) Langley Research Center which documents the development of an operations and support (O&S) cost model as part of a larger life cycle cost (LCC) structure. It is intended for use during the conceptual design of new launch vehicles and spacecraft. This research is being conducted under NASA Research Grant NAG-1-1327. This research effort changes the focus from that of the first two years in which a reliability and maintainability model was developed to the initial development of an operations and support life cycle cost model. Cost categories were initially patterned after NASA's three axis work breakdown structure consisting of a configuration axis (vehicle), a function axis, and a cost axis. A revised cost element structure (CES), which is currently under study by NASA, was used to established the basic cost elements used in the model. While the focus of the effort was on operations and maintenance costs and other recurring costs, the computerized model allowed for other cost categories such as RDT&E and production costs to be addressed. Secondary tasks performed concurrent with the development of the costing model included support and upgrades to the reliability and maintainability (R&M) model. The primary result of the current research has been a methodology and a computer implementation of the methodology to provide for timely operations and support cost analysis during the conceptual design activities.

  10. Local Control Model of Excitation–Contraction Coupling in Skeletal Muscle

    PubMed Central

    Stern, Michael D.; Pizarro, Gonzalo; Ríos, Eduardo

    1997-01-01

    This is a quantitative model of control of Ca2+ release from the sarcoplasmic reticulum in skeletal muscle, based on dual control of release channels (ryanodine receptors), primarily by voltage, secondarily by Ca2+ (Ríos, E., and G. Pizarro. 1988. NIPS. 3:223–227). Channels are positioned in a double row array of between 10 and 60 channels, where exactly half face voltage sensors (dihydropyridine receptors) in the transverse (t) tubule membrane (Block, B.A., T. Imagawa, K.P. Campbell, and C. Franzini-Armstrong. 1988. J. Cell Biol. 107:2587–2600). We calculate the flux of Ca2+ release upon different patterns of pulsed t-tubule depolarization by explicit stochastic simulation of the states of all channels in the array. Channels are initially opened by voltage sensors, according to an allosteric prescription (Ríos, E., M. Karhanek, J. Ma, A. González. 1993. J. Gen. Physiol. 102:449–482). Ca2+ permeating the open channels, diffusing in the junctional gap space, and interacting with fixed and mobile buffers produces defined and changing distributions of Ca2+ concentration. These concentrations interact with activating and inactivating channel sites to determine the propagation of activation and inactivation within the array. The model satisfactorily simulates several whole-cell observations, including kinetics and voltage dependence of release flux, the “paradox of control,” whereby Ca2+-activated release remains under voltage control, and, most surprisingly, the “quantal” aspects of activation and inactivation (Pizarro, G., N. Shirokova, A. Tsugorka, and E. Ríos. 1997. J. Physiol. 501:289–303). Additionally, the model produces discrete events of activation that resemble Ca2+ sparks (Cheng, H., M.B. Cannell, and W.J. Lederer. 1993. Science (Wash. DC). 262:740–744). All these properties result from the intersection of stochastic channel properties, control by local Ca2+, and, most importantly, the one dimensional geometry of the array and its

  11. "SERPS Up": Support, Engagement and Retention of Postgraduate Students--A Model of Postgraduate Support

    ERIC Educational Resources Information Center

    Alston, Margaret; Allan, Julaine; Bell, Karen; Brown, Andy; Dowling, Jane; Hamilton, Pat; McKinnon, Jenny; McKinnon, Noela; Mitchell, Rol; Whittenbury, Kerri; Valentine, Bruce; Wicks, Alison; Williams, Rachael

    2005-01-01

    The federal government's 1999 White Paper Knowledge and Innovation: a policy statement on research and research training, notes concerns about retention and completion rates in doctoral studies programs in Australia. This paper outlines a model of higher education support developed at the Centre for Rural Social Research at Charles Sturt…

  12. Composable Framework Support for Software-FMEA Through Model Execution

    NASA Astrophysics Data System (ADS)

    Kocsis, Imre; Patricia, Andras; Brancati, Francesco; Rossi, Francesco

    2016-08-01

    Performing Failure Modes and Effect Analysis (FMEA) during software architecture design is becoming a basic requirement in an increasing number of domains; however, due to the lack of standardized early design phase model execution, classic SW-FMEA approaches carry significant risks and are human effort-intensive even in processes that use Model-Driven Engineering.Recently, modelling languages with standardized executable semantics have emerged. Building on earlier results, this paper describes framework support for generating executable error propagation models from such models during software architecture design. The approach carries the promise of increased precision, decreased risk and more automated execution for SW-FMEA during dependability- critical system development.

  13. Bridging the financial gap through providing contract services: a model for publicly funded clinical biobanks.

    PubMed

    Kozlakidis, Zisis; Mant, Christine; Cason, John

    2012-08-01

    Biobanks offer translational researchers a novel method of obtaining clinical research materials, patient data, and relevant ethical and legal permissions. However, such tissue collections are expensive to establish and maintain. Current opinion is that such initiatives can only survive with core funding from Government or major funding bodies. Given the present climate of financial austerity, funding agencies may be tempted to invest in fast-return research projects rather than in maintaining tissue collections, whose benefits will only become apparent in much longer timescales. Thus, securing additional funding for biobanks could provide a valuable boost enabling an extension of core services. Here we suggest that using biobank expertise to offer contract services to clinicians and industry may be an alternative approach to obtaining such extra funding.

  14. 48 CFR 1552.209-74 - Limitation of future contracting.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... FUTURE CONTRACTING, ALTERNATE IV (ESS) (SEP 2013) (a) The parties to this contract agree that the...), Superfund Technical Assistance and Removal Team (START), and Enforcement Support Services (ESS)...

  15. Contracting to Demonstrate Teacher Competencies.

    ERIC Educational Resources Information Center

    Lux, John E.

    1979-01-01

    The Lincoln, Nebraska, Teacher Corps' contracting process offers an effective model for team teaching, individualizing/personalizing instruction, and demonstrating both teacher and learner levels of competency. (JMF)

  16. Design Approaches to Support Preservice Teachers in Scientific Modeling

    NASA Astrophysics Data System (ADS)

    Kenyon, Lisa; Davis, Elizabeth A.; Hug, Barbara

    2011-02-01

    Engaging children in scientific practices is hard for beginning teachers. One such scientific practice with which beginning teachers may have limited experience is scientific modeling. We have iteratively designed preservice teacher learning experiences and materials intended to help teachers achieve learning goals associated with scientific modeling. Our work has taken place across multiple years at three university sites, with preservice teachers focused on early childhood, elementary, and middle school teaching. Based on results from our empirical studies supporting these design decisions, we discuss design features of our modeling instruction in each iteration. Our results suggest some successes in supporting preservice teachers in engaging students in modeling practice. We propose design principles that can guide science teacher educators in incorporating modeling in teacher education.

  17. Organizational analysis of three community support program models.

    PubMed

    Reinke, B; Greenley, J R

    1986-06-01

    Little attention has been paid to the organizational and administrative characteristics of effective community support programs for the chronic mentally ill. The authors analyzed three successful support programs in Wisconsin that employ three different models of service delivery: one provides services through caseworkers who carry specialized caseloads, another through local nonprofessionals who work with a centrally located program coordinator, and the third through a team of various mental health workers. Each program has tailored its organizational process to suit the types of clients it sees, the size of its catchment area, and the availability of other professional resources. The interrelated strengths and weaknesses of each model are discussed.

  18. Contract Design, Supply Chain Complexity, and Accountability in Federal Contracts

    DTIC Science & Technology

    2016-04-30

    multinomial logistical regression model to test our hypotheses. We estimate preferences for incentive contracts compared to fixed price contracts, cost...University of Tennessee Amanda Girth, Assistant Professor, The Ohio State University An Approach for Modeling Supplier Resilience Kash Barker, Associate...endogenous risk is low, suppliers tend to bear most of the disruption risk by agreeing to fixed price contracts. Conversely, when endogenous risk is

  19. 48 CFR 1022.7000 - Contract clause.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... MINORITY AND WOMEN INCLUSION Fair inclusion of minorities and women 1022.7000 Contract clause. Insert the clause at 1052.222-70, Minority and Women Inclusion, in all solicitations and contracts in support...

  20. 48 CFR 19.812 - Contract administration.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Administration Services Components (available via the Internet at http://www.dcma.mil/casbook/casbook.htm)). (b... proposed transfer and its effect on contract performance and mission support. If the contracting...

  1. Effective Team Support: From Task and Cognitive Modeling to Software Agents for Time-Critical Complex Work Environments

    NASA Technical Reports Server (NTRS)

    Remington, Roger W. (Technical Monitor); John, Bonnie E.; Sycara, Katia

    2005-01-01

    The purpose of this research contract was to perform multidisciplinary research between CMU psychologists, computer scientists and NASA researchers to design a next generation collaborative system to support a team of human experts and intelligent agents. To achieve robust performance enhancement of such a system, we had proposed to perform task and cognitive modeling to thoroughly understand the impact technology makes on the organization and on key individual personnel. Guided by cognitively-inspired requirements, we would then develop software agents that support the human team in decision making, information filtering, information distribution and integration to enhance team situational awareness. During the period covered by this final report, we made substantial progress in completing a system for empirical data collection, cognitive modeling, and the building of software agents to support a team's tasks, and in running experiments for the collection of baseline data.

  2. Effective Team Support: From Task and Cognitive Modeling to Software Agents for Time-Critical Complex Work Environments

    NASA Technical Reports Server (NTRS)

    Remington, Roger W. (Technical Monitor); John, Bonnie E.; Sycara, Katia

    2005-01-01

    The purpose of this research contract was to perform multidisciplinary research between CMU psychologists, computer scientists and NASA researchers to design a next generation collaborative system to support a team of human experts and intelligent agents. To achieve robust performance enhancement of such a system, we had proposed to perform task and cognitive modeling to thoroughly understand the impact technology makes on the organization and on key individual personnel. Guided by cognitively-inspired requirements, we would then develop software agents that support the human team in decision making, information filtering, information distribution and integration to enhance team situational awareness. During the period covered by this final report, we made substantial progress in completing a system for empirical data collection, cognitive modeling, and the building of software agents to support a team's tasks, and in running experiments for the collection of baseline data.

  3. Process Evaluation of a Participatory Supportive Return to Work Program for Workers Without a Permanent Employment Contract, Sick-Listed Due to a Common Mental Disorder.

    PubMed

    Lammerts, Lieke; Schaafsma, Frederieke G; van Mechelen, Willem; Anema, Johannes R

    2016-01-25

    Purpose This study aimed to perform a process evaluation of a participatory supportive return to work program for workers without a (permanent) employment contract, sick-listed due to a common mental disorder. The program consisted of a participatory approach, integrated care and direct placement in a competitive job. Our main questions were: were these components realized in practice and in accordance with the protocol? The evaluation took place alongside a randomized controlled trial. Methods The study population consisted of workers who filed a sickness benefit claim at the Dutch Social Security Agency, professionals of this agency and of vocational rehabilitation agencies. We focused on sick-listed workers and professionals who had actually participated in the intervention. Data was collected mainly by questionnaires. Results Only 36 out of 94 intervention group participants started with the program. In half of these cases application of integrated care was reported. Most other steps in the program were completed. However, fidelity to the protocol was low to reasonable. Much delay was observed in the execution of the program and only two sick-listed workers were placed in a competitive job. Still, satisfaction with the participatory approach was good. Conclusions Despite the positive evaluation of the participatory approach, the full program was executed less successfully compared to similar programs evaluated in earlier studies. This will probably affect the outcomes of our trial. Findings from this study will help to interpret these outcomes. Nevertheless, more knowledge is needed about experiences of stakeholders who participated in the program. Trial Registration NTR3563.

  4. A numerical cloud model for the support of laboratory experimentation

    NASA Technical Reports Server (NTRS)

    Hagen, D. E.

    1979-01-01

    A numerical cloud model is presented which can describe the evolution of a cloud starting from moist aerosol-laden air through the diffusional growth regime. The model is designed for the direct support of cloud chamber laboratory experimentation, i.e., experiment preparation, real-time control and data analysis. In the model the thermodynamics is uncoupled from the droplet growth processes. Analytic solutions for the cloud droplet growth equations are developed which can be applied in most laboratory situations. The model is applied to a variety of representative experiments.

  5. National Environmenal Policy Act Contracting Reform Guidance: Phase 1

    SciTech Connect

    1995-08-01

    The NEPA Contracting Quality Improvement Team identified several contracting improvements to reduce the cost and time for the NEPA process. The team`s February 1995 report recommended a series of steps to achieve the improvements, including issuance of contracting guidance. The guidance will be issued in three phases. This Phase I guidance implements the team`s short-term recommendations. It provides model statements of work and a sample schedule of contractor deliverables, establishes a pilot program for evaluating performance of NEPA support contractors, and describes information resources available on the DOE NEPA Web.

  6. Managing Higher Education in a Climate of Contraction: A Conceptual Model.

    ERIC Educational Resources Information Center

    Doyle, K. J.

    1980-01-01

    Five categories of opportunity for managing institutions successfully in no-growth periods include: producing new or different products, improving productivity with new production methods, opening new markets, locating new sources of support, and restructuring activities. (MSE)

  7. Model-supported virtual environment for prostate cancer pattern analysis

    NASA Astrophysics Data System (ADS)

    Yu, Ping; McClain, Maxine A.; Xuan, Jianhua; Wang, Yue J.; Sesterhenn, Isabell A.; Moul, Judd W.; Zhang, Wei; Mun, Seong K.

    1999-05-01

    As a step toward understanding complex spatial distribution patterns of prostate cancers, a 3D master model of the prostate, showing major anatomical structures and probability maps of the location of tumors, has been pilot developed. A virtual environment supported by the 3D master model and in vivo imaging features, will be used to evaluate, simulate, and optimize the image guided needle biopsy and radiation therapy, thus potentially improving the efficacy of prostate cancer diagnosis, staging, and treatment. A deformable graphics algorithm has been developed to reconstruct the graphics models from 200 serially sectioned whole mount radical prostatectomy specimens and to support computerized needle biopsy simulations. For the construction of a generic model, a principal-axes 3D registration technique has been developed. Simulated evaluation and real data experiment have shown the satisfactory performance of the method in constructing initial generic model with localized prostate cancer placement. For the construction of statistical model, a blended model registration technique is advanced to perform a non-linear warping of the individual model to the generic model so that the prostate cancer probability distribution maps can be accurately positioned. The method uses a spine- surface model and a linear elastic model to dynamically deform both the surface and volume where object re-slicing is required. For the interactive visualization of the 3D master model, four modes of data display are developed: (1) transparent rendering of the generic model, (2) overlaid rendering of cancer distributions, (3) stereo rendering, and (4) true volumetric display, and a model-to-image registration technique using synthetic image phantoms is under investigation. Preliminary results have shown that use of this master model allows correct understanding of prostate cancer distribution patterns and rational optimization of prostate biopsy and radiation therapy strategies.

  8. Outcomes of a group intensive peer-support model of case management for supported housing.

    PubMed

    Tsai, Jack; Rosenheck, Robert A

    2012-12-01

    Community-based intensive case management may be more intense than necessary and may be socially isolating for persons living in supported housing. This study evaluated a group intensive peer-support (GIPS) model of case management that was implemented in a supported housing program for homeless veterans with a broad range of psychiatric,substance use, and general medical problems. Group meetings led by case managers are the default mode of case management support, and individual intensive case management is provided only when clinically necessary. GIPS was implemented by the U.S. Department of Housing and Urban Development–Veterans Affairs Supportive Housing(HUD-VASH) program at one demonstration site in April 2010. The study used administrative data to compare outcomes, service delivery, and timing of housing acquisition among clients of the demonstration site one year before (N=102) and after (N=167) GIPS implementation and among clients of other HUD-VASH sites across the country before (N=9,659) and after (N=21,318) implementation of GIPS at the demonstration site. After adjustment for differences in baseline characteristics, the analyses found that GIPS implementation was associated with a greater increase in social integration ratings, a greater number of case manager services, and faster acquisition of Section 8 housing vouchers after program admission compared with outcomes at the same site before GIPS implementation and at the other sites before and after implementation. GIPS may be a viable service model of supported housing that represents a recovery-oriented approach that can be scaled up to address homelessness.

  9. Tactile length contraction as Bayesian inference

    PubMed Central

    Tong, Jonathan; Ngo, Vy

    2016-01-01

    To perceive, the brain must interpret stimulus-evoked neural activity. This is challenging: The stochastic nature of the neural response renders its interpretation inherently uncertain. Perception would be optimized if the brain used Bayesian inference to interpret inputs in light of expectations derived from experience. Bayesian inference would improve perception on average but cause illusions when stimuli violate expectation. Intriguingly, tactile, auditory, and visual perception are all prone to length contraction illusions, characterized by the dramatic underestimation of the distance between punctate stimuli delivered in rapid succession; the origin of these illusions has been mysterious. We previously proposed that length contraction illusions occur because the brain interprets punctate stimulus sequences using Bayesian inference with a low-velocity expectation. A novel prediction of our Bayesian observer model is that length contraction should intensify if stimuli are made more difficult to localize. Here we report a tactile psychophysical study that tested this prediction. Twenty humans compared two distances on the forearm: a fixed reference distance defined by two taps with 1-s temporal separation and an adjustable comparison distance defined by two taps with temporal separation t ≤ 1 s. We observed significant length contraction: As t was decreased, participants perceived the two distances as equal only when the comparison distance was made progressively greater than the reference distance. Furthermore, the use of weaker taps significantly enhanced participants' length contraction. These findings confirm the model's predictions, supporting the view that the spatiotemporal percept is a best estimate resulting from a Bayesian inference process. PMID:27121574

  10. Applications of system dynamics modelling to support health policy.

    PubMed

    Atkinson, Jo-An M; Wells, Robert; Page, Andrew; Dominello, Amanda; Haines, Mary; Wilson, Andrew

    2015-07-09

    The value of systems science modelling methods in the health sector is increasingly being recognised. Of particular promise is the potential of these methods to improve operational aspects of healthcare capacity and delivery, analyse policy options for health system reform and guide investments to address complex public health problems. Because it lends itself to a participatory approach, system dynamics modelling has been a particularly appealing method that aims to align stakeholder understanding of the underlying causes of a problem and achieve consensus for action. The aim of this review is to determine the effectiveness of system dynamics modelling for health policy, and explore the range and nature of its application. A systematic search was conducted to identify articles published up to April 2015 from the PubMed, Web of Knowledge, Embase, ScienceDirect and Google Scholar databases. The grey literature was also searched. Papers eligible for inclusion were those that described applications of system dynamics modelling to support health policy at any level of government. Six papers were identified, comprising eight case studies of the application of system dynamics modelling to support health policy. No analytic studies were found that examined the effectiveness of this type of modelling. Only three examples engaged multidisciplinary stakeholders in collective model building. Stakeholder participation in model building reportedly facilitated development of a common 'mental map' of the health problem, resulting in consensus about optimal policy strategy and garnering support for collaborative action. The paucity of relevant papers indicates that, although the volume of descriptive literature advocating the value of system dynamics modelling is considerable, its practical application to inform health policy making is yet to be routinely applied and rigorously evaluated. Advances in software are allowing the participatory model building approach to be extended to

  11. Arctic Ocean Model Intercomparison Project (AOMIP): Travel Support for Workshops

    DTIC Science & Technology

    2012-03-31

    Luneva (POL): new to arctic modeling  Per Pemberton (SMHI): new to arctic modeling  Bill Hibler (IARC): senior scientist All supported scientists...grad student 4 18. Robert Osinski (NPS): post-postdoc 19. J-P Paquin (UQAM): grad student 20. Per Pemberton (Stockholm): grad student 21. Cecilia...Proshutinsky, A., Y. Aksenov, J. Clement-Kinney, R. Gerdes, E. Golubeva, D. Holland, G. Holloway, A. John , M. Johnson, E. Popova, M. Steele, and E

  12. Ostwald ripening of charged supported metal nanoparticles: Schottky model

    NASA Astrophysics Data System (ADS)

    Zhdanov, Vladimir P.

    2015-07-01

    Due to high surface area, supported metal nanoparticles are thermodynamically prone to sintering. The experimental studies of this process exhibit sometimes transient bimodal particle size distributions. Such observations may result from the support heterogeneity. Looking retrospectively, one can also find the prediction that in the case of Ostwald ripening this feature can be related to charge of metal nanoparticles. In real systems, this charge is often associated with the metal-support interaction and can be interpreted in the framework of the Schottky model. Using this model, the author shows that the charge redistribution cannot be behind bimodal particle size distributions. Moreover, the corresponding contribution to the driving force for Ostwald ripening is typically much smaller than the conventional one.

  13. Psychological contract breach and outcomes: Combining meta-analysis and structural equation models.

    PubMed

    Topa Cantisano, Gabriela; Morales Domínguez, J Francisco; Depolo, Marco

    2008-08-01

    In this study, meta-analytic procedures were used to examine the relationships between psychological contract perceived breach and certain outcome variables, such as organizational commitment, job satisfaction and organizational citizenship behaviours (OCB). Our review of the literature generated 41 independent samples in which perceived breach was used as a predictor of these personal and organizational outcomes. A medium effect size (ES) for desirable outcomes (job satisfaction, organizational commitment, organizational trust, OCB and performance) was obtained (r=-.35). For undesirable outcomes (neglect in role duties and intention to leave), ES were also medium (r=.31). When comparing attitudinal (job satisfaction, organizational commitment, organizational trust) and behavioural outcomes (OCB, neglect in role duties and performance), a stronger ES was found for attitudinal (r=-.24) than for behavioural outcomes (r=-.11). Potential moderator variables were examined, and it was found that they explained only a percentage of variability of primary studies. Structural equation analysis of the pooled meta-analytical correlation matrix indicated that the relationships of perceived breach with satisfaction, OCB, intention to leave and performance are fully mediated by organizational trust and commitment. Results are discussed in order to suggest theoretical and empirical implications.

  14. Transition to Operations Support at the Community Coordinated Modeling Center

    NASA Technical Reports Server (NTRS)

    Hesse, M.

    2005-01-01

    The Community Coordinated Modeling Center (CCMC) is a multi-agency partnership, which aims at the creation of next generation space weather models. The goal of the CCMC is to support the research and developmental work necessary to substantially increase the present-day modeling capability for space weather purposes, and to provide models for transition to the rapid prototyping centers at the space weather forecast centers. This goal requires close collaborations with and substantial involvement of the research community. The physical regions to be addressed by CCMC-related activities range from the solar atmosphere to the Earth's upper atmosphere. The CCMC is an integral part of the National Space Weather Program Implementation Plan, of NASA's Living With a Star (LWS) initiative, and of the Department of Defense Space Weather Transition Plan. CCMC includes a facility at NASA Goddard Space Flight Center, as well as distributed computing facilities provided by the US Air Force. CCMC also provides, to the research community, access to state-of-the-art space research models. This paper will focus on a status report on CCMC activities in support of model transition to operations at US space weather forecasting centers. In particular, an update will be given on past and present transition activities, on developments that address operational needs, and on future opportunities for transition-to-operations support.

  15. Modeling actions and operations to support mission preparation

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.; Ryan, D. P.; Schreckenghost, D. L.

    1994-01-01

    This paper describes two linked technology development projects to support Space Shuttle ground operations personnel, both during mission preparation analysis and related analyses in missions. The Space Propulsion Robust Analysis Tool (SPRAT) will provide intelligent support and automation for mission analysis setup, interpretation, reporting and documentation. SPRAT models the actions taken by flight support personnel during mission preparation and uses this model to generate an action plan. CONFIG will provide intelligent automation for procedure analyses and failure impact analyses, by simulating the interactions between operations and systems with embedded failures. CONFIG models the actions taken by crew during space vehicle malfunctions and simulates how the planned action sequences in procedures affect a device model. Jointly the SPRAT and CONFIG projects provide an opportunity to investigate how the nature of a task affects the representation of actions, and to determine a more general action representation supporting a broad range of tasks. This paper describes the problems in representing actions for mission preparation and their relation to planning and scheduling.

  16. Rectangular Array Model Supporting Students' Spatial Structuring in Learning Multiplication

    ERIC Educational Resources Information Center

    Shanty, Nenden Octavarulia; Wijaya, Surya

    2012-01-01

    We examine how rectangular array model can support students' spatial structuring in learning multiplication. To begin, we define what we mean by spatial structuring as the mental operation of constructing an organization or form for an object or set of objects. For that reason, the eggs problem was chosen as the starting point in which the…

  17. Educating All Learners: Refocusing the Comprehensive Support Model.

    ERIC Educational Resources Information Center

    Obiakor, Festus E., Ed.; Grant, Patrick A., Ed.; Dooley, Elizabeth A., Ed.

    This collection of papers addresses the importance of maximizing the fullest potential of all students and leaving no child behind. The 14 papers are: (1) "The Comprehensive Support Model for All Learners: Conceptualization and Meaning" (Festus E. Obiakor, Pauline Harris-Obiakor, and Ramel L. Smith); (2) "The Power of the `Self' in Education"…

  18. Modeling Positive Behavior Interventions and Supports for Preservice Teachers

    ERIC Educational Resources Information Center

    Hill, Doris Adams; Flores, Margaret M.

    2014-01-01

    The authors modeled programwide positive behavior interventions and supports (PBIS) principles to 26 preservice teachers during consolidated yearly extended school year (ESY) services delivered to elementary students from four school districts. While PBIS were in place for preservice teachers to implement with students, a similar system was…

  19. MSW Time to Tumor Model and Supporting Documentation

    EPA Science Inventory

    The multistage Weibull (MSW) time-to-tumor model and related documentation were developed principally (but not exclusively) for conducting time-to-tumor analyses to support risk assessments under the IRIS program. These programs and related docum...

  20. Educating All Learners: Refocusing the Comprehensive Support Model.

    ERIC Educational Resources Information Center

    Obiakor, Festus E., Ed.; Grant, Patrick A., Ed.; Dooley, Elizabeth A., Ed.

    This collection of papers addresses the importance of maximizing the fullest potential of all students and leaving no child behind. The 14 papers are: (1) "The Comprehensive Support Model for All Learners: Conceptualization and Meaning" (Festus E. Obiakor, Pauline Harris-Obiakor, and Ramel L. Smith); (2) "The Power of the `Self' in Education"…

  1. MSW Time to Tumor Model and Supporting Documentation

    EPA Science Inventory

    The multistage Weibull (MSW) time-to-tumor model and related documentation were developed principally (but not exclusively) for conducting time-to-tumor analyses to support risk assessments under the IRIS program. These programs and related docum...

  2. Training of Existing Workers: Issues, Incentives and Models. Support Document

    ERIC Educational Resources Information Center

    Mawer, Giselle; Jackson, Elaine

    2005-01-01

    This document was produced by the authors based on their research for the report, "Training of Existing Workers: Issues, Incentives and Models," (ED495138) and is an added resource for further information. This support document is divided into the following sections: (1) The Retail Industry--A Snapshot; (2) Case Studies--Hardware, Retail…

  3. A Formal Model for the Study of Communication Support Systems.

    ERIC Educational Resources Information Center

    Holsapple, Clyde W.; And Others

    1996-01-01

    Documents the lack of conceptual frameworks for integrating research on organizational computer-based communications technologies. Formalizes an integrated model for studying computer communication support phenomena in organizations using a knowledge management perspective and set-theoretic notation. Defines two types of communications support…

  4. 48 CFR 242.202 - Assignment of contract administration.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... of, or installation of equipment at, radar or communication network sites; (H) Communications... sealift contracts); (O) Subsistence supplies; (P) Ballistic missile sites (contract administration offices may perform supporting administration of these contracts at missile activation sites during...

  5. Tropomyosin movement is described by a quantitative high-resolution model of X-ray diffraction of contracting muscle.

    PubMed

    Koubassova, Natalia A; Bershitsky, Sergey Y; Ferenczi, Michael A; Narayanan, Theyencheri; Tsaturyan, Andrey K

    2017-05-01

    Contraction of skeletal and cardiac muscle is controlled by Ca(2+) ions via regulatory proteins, troponin (Tn) and tropomyosin (Tpm) associated with the thin actin filaments in sarcomeres. In the absence of Ca(2+), Tn-C binds actin and shifts the Tpm strand to a position where it blocks myosin binding to actin, keeping muscle relaxed. According to the three-state model (McKillop and Geeves Biophys J 65:693-701, 1993), upon Ca(2+) binding to Tn, Tpm rotates about the filament axis to a 'closed state' where some myosin heads can bind actin. Upon strong binding of myosin heads to actin, Tpm rotates further to an 'open' position where neighboring actin monomers also become available for myosin binding. Azimuthal Tpm movement in contracting muscle is detected by low-angle X-ray diffraction. Here we used high-resolution models of actin-Tpm filaments based on recent cryo-EM data for calculating changes in the intensities of X-ray diffraction reflections of muscle upon transitions between different states of the regulatory system. Calculated intensities of actin layer lines provide a much-improved fit to the experimental data obtained from rabbit muscle fibers in relaxed and rigor states than previous lower-resolution models. We show that the intensity of the second actin layer line at reciprocal radii from 0.15 to 0.3 nm(-1) quantitatively reports the transition between different states of the regulatory system independently of the number of myosin heads bound to actin.

  6. Supporting Universal Prevention Programs: A Two-Phased Coaching Model

    PubMed Central

    Becker, Kimberly D.; Darney, Dana; Domitrovich, Celene; Keperling, Jennifer Pitchford; Ialongo, Nicholas S.

    2013-01-01

    Schools are adopting evidence-based programs designed to enhance students’ emotional and behavioral competencies at increasing rates (Hemmeter, Snyder, & Artman, 2011). At the same time, teachers express the need for increased support surrounding implementation of these evidence-based programs (Carter & Van Norman, 2010). Ongoing professional development in the form of coaching may enhance teacher skills and implementation (Noell et al., 2005; Stormont, Reinke, Newcomer, Darney, & Lewis, 2012). There exists a need for a coaching model that can be applied to a variety of teacher skill levels and one that guides coach decision-making about how best to support teachers. This article provides a detailed account of a two-phased coaching model with empirical support developed and tested with coaches and teachers in urban schools (Becker, Bradshaw, Domitrovich, & Ialongo, 2013). In the initial universal coaching phase, all teachers receive the same coaching elements regardless of their skill level. Then, in the tailored coaching phase, coaching varies according to the strengths and needs of each teacher. Specifically, more intensive coaching strategies are used only with teachers who need additional coaching supports whereas other teachers receive just enough support to consolidate and maintain their strong implementation. Examples of how coaches used the two-phased coaching model when working with teachers who were implementing two universal prevention programs (i.e., the PATHS® curriculum and PAX Good Behavior Game [PAX GBG]) provide illustrations of the application of this model. The potential reach of this coaching model extends to other school-based programs as well as other settings in which coaches partner with interventionists to implement evidence-based programs. PMID:23660973

  7. Supporting universal prevention programs: a two-phased coaching model.

    PubMed

    Becker, Kimberly D; Darney, Dana; Domitrovich, Celene; Keperling, Jennifer Pitchford; Ialongo, Nicholas S

    2013-06-01

    Schools are adopting evidence-based programs designed to enhance students' emotional and behavioral competencies at increasing rates (Hemmeter et al. in Early Child Res Q 26:96-109, 2011). At the same time, teachers express the need for increased support surrounding implementation of these evidence-based programs (Carter and Van Norman in Early Child Educ 38:279-288, 2010). Ongoing professional development in the form of coaching may enhance teacher skills and implementation (Noell et al. in School Psychol Rev 34:87-106, 2005; Stormont et al. 2012). There exists a need for a coaching model that can be applied to a variety of teacher skill levels and one that guides coach decision-making about how best to support teachers. This article provides a detailed account of a two-phased coaching model with empirical support developed and tested with coaches and teachers in urban schools (Becker et al. 2013). In the initial universal coaching phase, all teachers receive the same coaching elements regardless of their skill level. Then, in the tailored coaching phase, coaching varies according to the strengths and needs of each teacher. Specifically, more intensive coaching strategies are used only with teachers who need additional coaching supports, whereas other teachers receive just enough support to consolidate and maintain their strong implementation. Examples of how coaches used the two-phased coaching model when working with teachers who were implementing two universal prevention programs (i.e., the PATHS curriculum and PAX Good Behavior Game [PAX GBG]) provide illustrations of the application of this model. The potential reach of this coaching model extends to other school-based programs as well as other settings in which coaches partner with interventionists to implement evidence-based programs.

  8. Online model-based diagnosis to support autonomous operation of an advanced life support system

    NASA Technical Reports Server (NTRS)

    Biswas, Gautam; Manders, Eric-Jan; Ramirez, John; Mahadevan, Nagabhusan; Abdelwahed, Sherif

    2004-01-01

    This article describes methods for online model-based diagnosis of subsystems of the advanced life support system (ALS). The diagnosis methodology is tailored to detect, isolate, and identify faults in components of the system quickly so that fault-adaptive control techniques can be applied to maintain system operation without interruption. We describe the components of our hybrid modeling scheme and the diagnosis methodology, and then demonstrate the effectiveness of this methodology by building a detailed model of the reverse osmosis (RO) system of the water recovery system (WRS) of the ALS. This model is validated with real data collected from an experimental testbed at NASA JSC. A number of diagnosis experiments run on simulated faulty data are presented and the results are discussed.

  9. Online model-based diagnosis to support autonomous operation of an advanced life support system

    NASA Technical Reports Server (NTRS)

    Biswas, Gautam; Manders, Eric-Jan; Ramirez, John; Mahadevan, Nagabhusan; Abdelwahed, Sherif

    2004-01-01

    This article describes methods for online model-based diagnosis of subsystems of the advanced life support system (ALS). The diagnosis methodology is tailored to detect, isolate, and identify faults in components of the system quickly so that fault-adaptive control techniques can be applied to maintain system operation without interruption. We describe the components of our hybrid modeling scheme and the diagnosis methodology, and then demonstrate the effectiveness of this methodology by building a detailed model of the reverse osmosis (RO) system of the water recovery system (WRS) of the ALS. This model is validated with real data collected from an experimental testbed at NASA JSC. A number of diagnosis experiments run on simulated faulty data are presented and the results are discussed.

  10. Educational Support for Low-Performing Students in Mathematics: The Three-Tier Support Model in Finnish Lower Secondary Schools

    ERIC Educational Resources Information Center

    Ekstam, Ulrika; Linnanmäki, Karin; Aunio, Pirjo

    2015-01-01

    In 2011, there was a legislative reform regarding educational support in Finland, with a focus on early identification, differentiation and flexible arrangement of support using a multi-professional approach, the three-tier support model. The main aim of this study was to investigate what educational support practices are used with low-performing…

  11. The effect of alkylating agents on model supported metal clusters

    SciTech Connect

    Erdem-Senatalar, A.; Blackmond, D.G.; Wender, I. . Dept. of Chemical and Petroleum Engineering); Oukaci, R. )

    1988-01-01

    Interactions between model supported metal clusters and alkylating agents were studied in an effort to understand a novel chemical trapping technique developed for identifying species adsorbed on catalyst surfaces. It was found that these interactions are more complex than had previously been suggested. Studies were completed using deuterium-labeled dimethyl sulfate (DMS), (CH{sub 3}){sub 2}SO{sub 4}, as a trapping agent to interact with the supported metal cluster ethylidyne tricobalt enneacarbonyl. Results showed that oxygenated products formed during the trapping reaction contained {minus}OCD{sub 3} groups from the DMS, indicating that the interaction was not a simple alkylation. 18 refs., 1 fig., 3 tabs.

  12. Speckle tracking echocardiography assessment of global and regional contraction dysfunction in the mice model of pressure overload.

    PubMed

    Wang, Guan; Zhang, Le; Ruan, Lei; Quan, Xiao-qing; Yang, Jun; Lv, Cai-xia; Zhang, Cun-tai

    2015-04-01

    Speckle tracking echocardiography (STE) has been applied to the evaluation of cardiac contraction dysfunction. However, there were few studies on alteration of global and regional STE parameters in the process of myocardial hypertrophy and heart failure. In this study, STE was applied to evaluate the global and regional cardiac function under heart failure and hypertrophy in the mice model of pressure overload. Adult mice were subjected to mild or severe aortic banding with a 25 Gauge (G) or 27 G needle. After surgery, STE and conventional echocardiography were used in the sham group (n=10), mild trans-aortic banding (TAB) group (n=14) and severe TAB group (n=10) for 8 weeks. The results showed that the mice subjected to severe TAB showed a significant change in fractional shortening (FS), left ventricular (LV) mass, and left ventricular end diastolic diameter (LVEDD) (P<0.05 for each). Meanwhile, there were no significant differences in FS and LVEDD between the sham group and mild TAB group during the experimental procedures (P>0.05 for both). STE analysis revealed that longitudinal strain (LS) was significantly decreased in the severe TAB group as compared with the sham and mild TAB groups (P<0.05 for both) from the postoperative week 1. LS in the mild TAB group was reduced as compared to the sham group (P<0.05). Radial strain (RS) and circumferential strain (CS) were significantly decreased in the severe TAB group as compared to the sham group and the mild TAB group (P<0.05 for both) from the postoperative week 1 (P<0.05 for both). Compared to the sham group, CS in the mild TAB group maintained unchanged during the test period, and RS was reduced only on the postoperative week 6 (P<0.05). Finally, regional contraction dysfunction was analyzed in both hypertrophic and failing myocardium in longitudinal and radial directions. It was found that LS was largest in the apex region and RS was smallest in the apex region in the healthy and hypertrophic myocardium. It

  13. Decision Support Model for Optimal Management of Coastal Gate

    NASA Astrophysics Data System (ADS)

    Ditthakit, Pakorn; Chittaladakorn, Suwatana

    2010-05-01

    The coastal areas are intensely settled by human beings owing to their fertility of natural resources. However, at present those areas are facing with water scarcity problems: inadequate water and poor water quality as a result of saltwater intrusion and inappropriate land-use management. To solve these problems, several measures have been exploited. The coastal gate construction is a structural measure widely performed in several countries. This manner requires the plan for suitably operating coastal gates. Coastal gate operation is a complicated task and usually concerns with the management of multiple purposes, which are generally conflicted one another. This paper delineates the methodology and used theories for developing decision support modeling for coastal gate operation scheduling. The developed model was based on coupling simulation and optimization model. The weighting optimization technique based on Differential Evolution (DE) was selected herein for solving multiple objective problems. The hydrodynamic and water quality models were repeatedly invoked during searching the optimal gate operations. In addition, two forecasting models:- Auto Regressive model (AR model) and Harmonic Analysis model (HA model) were applied for forecasting water levels and tide levels, respectively. To demonstrate the applicability of the developed model, it was applied to plan the operations for hypothetical system of Pak Phanang coastal gate system, located in Nakhon Si Thammarat province, southern part of Thailand. It was found that the proposed model could satisfyingly assist decision-makers for operating coastal gates under various environmental, ecological and hydraulic conditions.

  14. Toward a transtheoretical model of interprofessional education: stages, processes and forces supporting institutional change.

    PubMed

    Clark, Phillip G

    2013-01-01

    The history of interprofessional education (IPE) in the USA is a checkered one, characterized by boom and bust cycles of advancement and retrenchment, expansion and contraction. The successful development, implementation and continuation of IPE in health and social care in US higher education institutions all depend on a number of factors related to how individuals and organizations do or do not support it in the academic setting. Deliberate and planned change to advance IPE requires a comprehensive theoretical framework to guide it and insure its success. A transtheoretical model (TTM) of institutional change is proposed as a comprehensive framework of the stages, processes and forces that can facilitate and maintain change in support of IPE. The TTM framework recognizes the complexity of change, and captures and organizes important elements from different organizational theories. It also provides a structure for conceptualizing the multiple dimensions needed for change, offering intervention strategies and leverage points to be used by leaders in promoting and maintaining it. Finally, the TTM model suggests that the stabilization of IPE programs over the long term is dependent on a real and significant shift in institutional values in response to forces from both within and without the organization.

  15. A simple model of force generation by skeletal muscle during dynamic isometric contractions.

    PubMed

    Bobet, J; Stein, R B

    1998-08-01

    The force that an isometric skeletal muscle will produce in response to time-varying stimulation ("dynamic isometric" force) is important both for understanding muscle function and for designing neuroprostheses. This paper reports a model for predicting the force produced by an isometric skeletal muscle at rest length in response to a wide range of stimulation patterns. The model consists of two linear, first-order systems separated by a static nonlinearity. The rate constant of the second first-order system varies with force level. The model was validated using three cat soleus and three cat plantaris muscles. The following whole-nerve stimulation trains were used: single pulses (twitches), 2-4 pulses, constant rates, triangularly modulated interpulse intervals, and randomly modulated interpulse intervals. The model reproduced most responses accurately. The model shows that a force-dependent rate constant is essential for model validity, and could be used in the control of neuroprostheses.

  16. A coupled electromechanical model for the excitation-dependent contraction of skeletal muscle.

    PubMed

    Böl, Markus; Weikert, Roman; Weichert, Christine

    2011-10-01

    This work deals with the development and implementation of an electromechanical skeletal muscle model. To this end, a recently published hyperelastic constitutive muscle model with transversely isotropic characteristics, see Ehret et al. (2011), has been weakly coupled with Ohm's law describing the electric current. In contrast to the traditional way of active muscle modelling, this model is rooted on a non-additive decomposition of the active and passive components. The performance of the proposed modelling approach is demonstrated by the use of three-dimensional illustrative boundary-value problems that include electromechanical analysis on tissue strips. Further, simulations on the biceps brachii muscle document the applicability of the model to realistic muscle geometries.

  17. Data and Models Needed to Support Civil Aviation

    NASA Astrophysics Data System (ADS)

    Onsager, Terrance; Biesecker, D. A.; Berger, Thomas; Rutledge, Robert

    2016-07-01

    The effective utilization of existing data and models is an important element in advancing the goals of the COSPAR/ILWS space weather roadmap. This is recommended to be done through innovative approaches to data utilization, including data driving, data assimilation, and ensemble modeling. This presentation will focus on observations and models needed to support space weather services for civil aviation and commercial space transportation. The service needs for aviation will be discussed, and an overview will be given of some of the existing data and models that can provide these services. Efforts underway to define the requirements for real-time data and to assess current modeling capabilities will be described. Recommendations will be offered for internationally coordinated activities that could identify priorities and further the roadmap goals.

  18. A recurrent support vector regression model in rainfall forecasting

    NASA Astrophysics Data System (ADS)

    Pai, Ping-Feng; Hong, Wei-Chiang

    2007-03-01

    To minimize potential loss of life and property caused by rainfall during typhoon seasons, precise rainfall forecasts have been one of the key subjects in hydrological research. However, rainfall forecast is made difficult by some very complicated and unforeseen physical factors associated with rainfall. Recently, support vector regression (SVR) models and recurrent SVR (RSVR) models have been successfully employed to solve time-series problems in some fields. Nevertheless, the use of RSVR models in rainfall forecasting has not been investigated widely. This study attempts to improve the forecasting accuracy of rainfall by taking advantage of the unique strength of the SVR model, genetic algorithms, and the recurrent network architecture. The performance of genetic algorithms with different mutation rates and crossover rates in SVR parameter selection is examined. Simulation results identify the RSVR with genetic algorithms model as being an effective means of forecasting rainfall amount. Copyright

  19. Support for an expanded tripartite influence model with gay men.

    PubMed

    Tylka, Tracy L; Andorka, Michael J

    2012-01-01

    This study investigated whether an expanded tripartite influence model would represent gay men's experiences. This model was extended by adding partners and gay community involvement as sources of social influence and considering dual body image pathways (muscularity and body fat dissatisfaction) to muscularity enhancement and disordered eating behaviors. Latent variable structural equation modeling analyses upheld this model for 346 gay men. Dual body image pathways to body change behaviors were supported, although three unanticipated interrelationships emerged, suggesting that muscularity and body fat concerns and behaviors may be more integrated for gay men. Internalization of the mesomorphic ideal, appearance comparison, muscularity dissatisfaction, and body fat dissatisfaction were key mediators in the model. Of the sources of social influence, friend and media pressure to be lean, gay community involvement, and partner, friend, media, and family pressures to be muscular made incremental contributions. Unexpectedly, certain sources were directly connected to body change behaviors.

  20. Structural finite-element modeling strategies for conformal load-bearing antenna structure (CLAS) (Air Force contract F33615-C-93-3200)

    NASA Astrophysics Data System (ADS)

    Lockyer, Allen J.; Alt, Kevin H.; Kudva, Jayanth N.; Kinslow, Robert W.; Goetz, Allan C.

    1997-06-01

    As the Wright Lab Air Force military contrast `Smart Skin Structures Technology Demonstration' (S3TD) Contract No. F33615-C-93-3200 draws toward conclusion, pertinent features of the program finite element modeling are presented. Analysis was performed to predict the structural performance of a complex multilayered composite panel that will be tested structurally (and electrically) for the final program deliverable. Application of finite element modeling to predict component load path and strain distribution in sandwich panel construction has been reported elsewhere in the literature for more standard applications. However, the unauthordox sandwich configuration lay-up posed by the quite revolutionary S3TD CLAS aircraft fuselage panel demonstration article merits further discussion. Difficulties with material selection, the stumbling block for many programs, are further exacerbated by conflicting material properties required to support simultaneous electrical and structural performance roles. The structural analysis challenge derives from S3TD's unique program goal, namely, to investigate load bearing antennas structural configurations, rather than conventional structurally inefficient `bolt in' installations, that have been the modus operandi for tactical aircraft antenna installations to date. Discussed below is a cost saving strategy where use of linear finite element analysis has been employed in the prediction of key structural parameters, and validated with risk reduction sub panel measurements, before proceeding to the final fabrication of a full scale 36 by 36 inch CLAS panel demonstration article.

  1. A New Availability-Payment Model for Pricing Performance-Based Logistics Contracts

    DTIC Science & Technology

    2014-06-17

    Petri net ) that produces availability and cost measures. The model is used to explore the optimum availability assessment window (length of time...model developed in this report uses an affine controller to drive a discrete event simulator ( Petri net ) that produces availability and cost measures...Integration Architecture ......................................................... 6 Figure 2. Petri Net Representation of the System

  2. A modular BLSS simulation model. [Bioregenerative Life Support System

    NASA Technical Reports Server (NTRS)

    Rummel, John D.; Volk, Tyler

    1987-01-01

    The coordination of material flows in earth's biosphere is largely made possible by the buffering effect of huge material reservoirs. Without similarly-sized buffers, a bioregenerative life support system (BLSS) for extraterrestrial use will be faced with coordination problems more acute than those in any ecosystem found on earth. A related problem in BLSS design is providing an interface between the various life-support processors, one that will allow for their coordination while still allowing for system expansion. A modular model is presented of a BLSS that interfaces system processors only with the material storage reservoirs, allowing those reservoirs to act as the principal buffers in the system and thus minimizing difficulties with processor coordination. The modular nature of the model allows independent development of the detailed submodels that exist within the model framework. Using this model, BLSS dynamics were investigated under normal conditions and under various failure modes. Partial and complete failures of various components, such as the waste processor or the plants themselves, drive transient responses in the model system, allowing examination of the effectiveness of the system reservoirs as buffers. The results from simulations of this sort will help to determine control strategies and BLSS design requirements. An evolved version of this model could be used as an interactive control aid in a future BLSS.

  3. Porflow modeling supporting the FY14 salstone special analysis

    SciTech Connect

    Flach, G.; Taylor, G.

    2014-04-01

    PORFLOW related analyses supporting the Saltstone FY14 Special Analysis (SA) described herein are based on prior modeling supporting the Saltstone FY13 SA. Notable changes to the previous round of simulations include: a) consideration of Saltstone Disposal Unit (SDU) design type 6 under “Nominal” and “Margin” conditions, b) omission of the clean cap fill from the nominal SDU 2 and 6 modeling cases as a reasonable approximation of greater waste grout fill heights, c) minor updates to the cementitious materials degradation analysis, d) use of updated I-129 sorption coefficient (Kd) values in soils, e) assignment of the pH/Eh environment of saltstone to the underlying floor concrete, considering down flow through an SDU, and f) implementation of an improved sub-model for Tc release in an oxidizing environment. These new model developments are discussed and followed by a cursory presentation of simulation results. The new Tc release sub-model produced significantly improved (smoother) flux results compared to the FY13 SA. Further discussion of PORFLOW model setup and simulation results will be presented in the FY14 SA, including dose results.

  4. Simulation of steady state and transient cardiac muscle response experiments with a Huxley-based contraction model.

    PubMed

    Negroni, Jorge A; Lascano, Elena C

    2008-08-01

    A cardiac muscle model is presented with the purpose of representing a wide range of mechanical experiments at constant and transient Ca(2+) concentration. Modifications of a previous model were: weak and power attached crossbridge states, a troponin system involving three consecutive regulatory troponin-tropomyosin units acting together in Ca(2+) kinetics and detachment constants depending on crossbridge length. This model improved cooperativity (Hill coefficient close to 4) and the force-velocity relationship, and incorporated the representation of the four phases of muscle response to length and force steps, isotonic shortening and isosarcometric contractions, preserving previous satisfactory results. Moreover, experimentally reported effects, such as length dependence on Ca(2+) affinity, the decreased cooperativity at higher Ca(2+) concentrations, temperature effects on the stiffness-frequency relationship and the isometric internal shortening due to series elasticity, were obtained. In conclusion, the model is more comprehensive than a previous version because it is able to represent a wider variety of steady state experiments, the mechanical variables in twitches can be adequately related to intracellular Ca(2+), and all the simulations were performed with the same set of parameters.

  5. Support effects studied on model supported catalysts. Progress report, April 1, 1991--March 31, 1992

    SciTech Connect

    Gorte, R.G.

    1991-11-01

    We are studying model catalysts in which the active phase is deposited onto flat oxide substrates in order to understand how a catalyst is affected by its support. We have examined the following growth and stability of titania overlayers which had been vapor deposited onto a Rh foil; the growth of Pt films on ZnO(0001)Zn and O(0001)O and compared the results to those obtained for Pt on {alpha}-Al{sub 2}O{sub 3}(0001). Samples were prepared by vapor deposition of Pt onto flat substrates in ultra high vacuum, and metal coverages were measured using a quartz-crystal, film thickness monitor; the structure and CO adsorption properties of Pt films vapor deposited onto a ZrO{sub 2}(100) crystal; the deposition of Rh on a ZrO{sub 2}(100) crystal; The absorption of NO on Pt particles supported on CeO{sub 2}, {alpha}-Al{sub 2}O{sub 3}(0001), and the Zn- and O-polar surfaces of ZnO(0001). We have investigated supported oxides in order to understand the acidic properties that have been reported for monolayer oxides. Our first studies were of amorphous, silicalumina catalysts. Finally, we have also begun to prepare model supported oxides in order to be able to used spectroscopic methods to characterize the sites formed on these materials. Our first studies were of niobia deposition on oxidized Al films and on an {alpha}-Al{sub 2}O{sub 3}(0001) crystal.

  6. Survey of the Effects of Exposure to 900 MHz Radiofrequency Radiation Emitted by a GSM Mobile Phone on the Pattern of Muscle Contractions in an Animal Model.

    PubMed

    Mortazavi, S M J; Rahimi, S; Talebi, A; Soleimani, A; Rafati, A

    2015-09-01

    The rapid development of wireless telecommunication technologies over the past decades, has led to significant changes in the exposure of the general public to electromagnetic fields. Nowadays, people are continuously exposed to different sources of electromagnetic fields such as mobile phones, mobile base stations, cordless phones, Wi-Fi routers, and power lines. Therefore, the last decade witnessed a rapidly growing concern about the possible health effects of exposure to electromagnetic fields emitted by these sources. In this study that was aimed at investigating the effects of exposure to radiofrequency (RF) radiation emitted by a GSM mobile phone on the pattern of contraction in frog's isolated gastrocnemius muscle after stimulation with single square pulses of 1V (1 Hz), pulse height of contractions, the time interval between two subsequent contractions and the latency period were measured. Our findings showed that the pulse height of contractions muscle could be affected by the exposure to electromagnetic fields. Especially, the latency period was effectively altered in RF-exposed samples. However, none of the experiments could show an alteration in the time interval between two subsequent contractions after exposure to electromagnetic fields. These findings support early reports which indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians including the effects on the pattern of muscle extractions.

  7. Survey of the Effects of Exposure to 900 MHz Radiofrequency Radiation Emitted by a GSM Mobile Phone on the Pattern of Muscle Contractions in an Animal Model

    PubMed Central

    Mortazavi, S. M. J.; Rahimi, S.; Talebi, A.; Soleimani, A.; Rafati, A.

    2015-01-01

    Background: The rapid development of wireless telecommunication technologies over the past decades, has led to significant changes in the exposure of the general public to electromagnetic fields. Nowadays, people are continuously exposed to different sources of electromagnetic fields such as mobile phones, mobile base stations, cordless phones, Wi-Fi routers, and power lines. Therefore, the last decade witnessed a rapidly growing concern about the possible health effects of exposure to electromagnetic fields emitted by these sources. Materials and Methods: In this study that was aimed at investigating the effects of exposure to radiofrequency (RF) radiation emitted by a GSM mobile phone on the pattern of contraction in frog’s isolated gastrocnemius muscle after stimulation with single square pulses of 1V (1 Hz), pulse height of contractions, the time interval between two subsequent contractions and the latency period were measured. Results: Our findings showed that the pulse height of contractions muscle could be affected by the exposure to electromagnetic fields. Especially, the latency period was effectively altered in RF-exposed samples. However, none of the experiments could show an alteration in the time interval between two subsequent contractions after exposure to electromagnetic fields. Conclusion: These findings support early reports which indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians including the effects on the pattern of muscle extractions. PMID:26396968

  8. Information Model Translation to Support a Wider Science Community

    NASA Astrophysics Data System (ADS)

    Hughes, John S.; Crichton, Daniel; Ritschel, Bernd; Hardman, Sean; Joyner, Ronald

    2014-05-01

    The Planetary Data System (PDS), NASA's long-term archive for solar system exploration data, has just released PDS4, a modernization of the PDS architecture, data standards, and technical infrastructure. This next generation system positions the PDS to meet the demands of the coming decade, including big data, international cooperation, distributed nodes, and multiple ways of analysing and interpreting data. It also addresses three fundamental project goals: providing more efficient data delivery by data providers to the PDS, enabling a stable, long-term usable planetary science data archive, and enabling services for the data consumer to find, access, and use the data they require in contemporary data formats. The PDS4 information architecture is used to describe all PDS data using a common model. Captured in an ontology modeling tool it supports a hierarchy of data dictionaries built to the ISO/IEC 11179 standard and is designed to increase flexibility, enable complex searches at the product level, and to promote interoperability that facilitates data sharing both nationally and internationally. A PDS4 information architecture design requirement stipulates that the content of the information model must be translatable to external data definition languages such as XML Schema, XMI/XML, and RDF/XML. To support the semantic Web standards we are now in the process of mapping the contents into RDF/XML to support SPARQL capable databases. We are also building a terminological ontology to support virtually unified data retrieval and access. This paper will provide an overview of the PDS4 information architecture focusing on its domain information model and how the translation and mapping are being accomplished.

  9. SPATIO-TEMPORAL MODELING OF AGRICULTURAL YIELD DATA WITH AN APPLICATION TO PRICING CROP INSURANCE CONTRACTS.

    PubMed

    Ozaki, Vitor A; Ghosh, Sujit K; Goodwin, Barry K; Shirota, Ricardo

    2008-11-01

    This article presents a statistical model of agricultural yield data based on a set of hierarchical Bayesian models that allows joint modeling of temporal and spatial autocorrelation. This method captures a comprehensive range of the various uncertainties involved in predicting crop insurance premium rates as opposed to the more traditional ad hoc, two-stage methods that are typically based on independent estimation and prediction. A panel data set of county-average yield data was analyzed for 290 counties in the State of Paraná (Brazil) for the period of 1990 through 2002. Posterior predictive criteria are used to evaluate different model specifications. This article provides substantial improvements in the statistical and actuarial methods often applied to the calculation of insurance premium rates. These improvements are especially relevant to situations where data are limited.

  10. SPATIO-TEMPORAL MODELING OF AGRICULTURAL YIELD DATA WITH AN APPLICATION TO PRICING CROP INSURANCE CONTRACTS

    PubMed Central

    Ozaki, Vitor A.; Ghosh, Sujit K.; Goodwin, Barry K.; Shirota, Ricardo

    2009-01-01

    This article presents a statistical model of agricultural yield data based on a set of hierarchical Bayesian models that allows joint modeling of temporal and spatial autocorrelation. This method captures a comprehensive range of the various uncertainties involved in predicting crop insurance premium rates as opposed to the more traditional ad hoc, two-stage methods that are typically based on independent estimation and prediction. A panel data set of county-average yield data was analyzed for 290 counties in the State of Paraná (Brazil) for the period of 1990 through 2002. Posterior predictive criteria are used to evaluate different model specifications. This article provides substantial improvements in the statistical and actuarial methods often applied to the calculation of insurance premium rates. These improvements are especially relevant to situations where data are limited. PMID:19890450

  11. Experimental support for KrF laser modeling. Final report

    SciTech Connect

    Not Available

    1989-07-19

    This paper is the final report for a project to do characterization studies on the KrF laser system. The project did experimental work on KrF lasers in support of modeling studies, with the objective being to see if this technology could be competitive for use in the ICF program. This program has provided LANL with data critical for their model development. Section 2 describes the laser extraction experiments together with the calibration of the diagnostics and the re-examination of the analysis procedure. Section 3 discusses the gain and transient absorption measurements, and Section 4 gives the conclusion for this program.

  12. Experimental-based modeling of a support structure as part of a full system model

    SciTech Connect

    CARNE,THOMAS G.; DOHRMANN,CLARK R.

    2000-02-29

    Structural dynamic systems are often attached to a support structure to simulate proper boundary conditions during testing. In some cases the support structure is fairly simple and can be modeled by discrete springs and dampers. In other cases the desired test conditions necessitate the use of a support structural that introduces dynamics of its own. For such cases a more complex structural dynamic model is required to simulate the response of the full combined system. In this paper experimental frequency response functions, admittance function modeling concepts, and least squares reductions are used to develop a support structure model including both translational and rotational degrees of freedom at an attachment location. Subsequently, the modes of the support structure are estimated, and a NASTRAN model is created for attachment to the tested system.

  13. PORFLOW Modeling Supporting The H-Tank Farm Performance Assessment

    SciTech Connect

    Jordan, J. M.; Flach, G. P.; Westbrook, M. L.

    2012-08-31

    Numerical simulations of groundwater flow and contaminant transport in the vadose and saturated zones have been conducted using the PORFLOW code in support of an overall Performance Assessment (PA) of the H-Tank Farm. This report provides technical detail on selected aspects of PORFLOW model development and describes the structure of the associated electronic files. The PORFLOW models for the H-Tank Farm PA, Rev. 1 were updated with grout, solubility, and inventory changes. The aquifer model was refined. In addition, a set of flow sensitivity runs were performed to allow flow to be varied in the related probabilistic GoldSim models. The final PORFLOW concentration values are used as input into a GoldSim dose calculator.

  14. Provider cost analysis supports results-based contracting out of maternal and newborn health services: an evidence-based policy perspective.

    PubMed

    Hatcher, Peter; Shaikh, Shiraz; Fazli, Hassan; Zaidi, Shehla; Riaz, Atif

    2014-11-13

    There is dearth of evidence on provider cost of contracted out services particularly for Maternal and Newborn Health (MNH). The evidence base is weak for policy makers to estimate resources required for scaling up contracting. This paper ascertains provider unit costs and expenditure distribution at contracted out government primary health centers to inform the development of optimal resource envelopes for contracting out MNH services. This is a case study of provider costs of MNH services at two government Rural Health Centers (RHCs) contracted out to a non-governmental organization in Pakistan. It reports on four selected Basic Emergency Obstetrical and Newborn Care (BEmONC) services provided in one RHC and six Comprehensive Emergency Obstetrical and Newborn Care (CEmONC) services in the other. Data were collected using staff interviews and record review to compile resource inputs and service volumes, and analyzed using the CORE Plus tool. Unit costs are based on actual costs of MNH services and are calculated for actual volumes in 2011 and for volumes projected to meet need with optimal resource inputs. The unit costs per service for actual 2011 volumes at the BEmONC RHC were antenatal care (ANC) visit USD$ 18.78, normal delivery US$ 84.61, newborn care US$ 16.86 and a postnatal care (PNC) visit US$ 13.86; and at the CEmONC RHC were ANC visit US$ 45.50, Normal Delivery US$ 148.43, assisted delivery US$ 167.43, C-section US$ 183.34, Newborn Care US$ 41.07, and PNC visit US$ 27.34. The unit costs for the projected volumes needed were lower due to optimal utilization of resources. The percentage distribution of expenditures at both RHCs was largest for salaries of technical staff, followed by salaries of administrative staff, and then operating costs, medicines, medical and diagnostic supplies. The unit costs of MNH services at the two contracted out government rural facilities remain higher than is optimal, primarily due to underutilization. Provider cost analysis

  15. Generation of isogenic D4Z4 contracted and noncontracted immortal muscle cell clones from a mosaic patient: a cellular model for FSHD.

    PubMed

    Krom, Yvonne D; Dumonceaux, Julie; Mamchaoui, Kamel; den Hamer, Bianca; Mariot, Virginie; Negroni, Elisa; Geng, Linda N; Martin, Nicolas; Tawil, Rabi; Tapscott, Stephen J; van Engelen, Baziel G M; Mouly, Vincent; Butler-Browne, Gillian S; van der Maarel, Silvère M

    2012-10-01

    In most cases facioscapulohumeral muscular dystrophy (FSHD) is caused by contraction of the D4Z4 repeat in the 4q subtelomere. This contraction is associated with local chromatin decondensation and derepression of the DUX4 retrogene. Its complex genetic and epigenetic cause and high clinical variability in disease severity complicate investigations on the pathogenic mechanism underlying FSHD. A validated cellular model bypassing the considerable heterogeneity would facilitate mechanistic and therapeutic studies of FSHD. Taking advantage of the high incidence of somatic mosaicism for D4Z4 repeat contraction in de novo FSHD, we have established a clonal myogenic cell model from a mosaic patient. Individual clones are genetically identical except for the size of the D4Z4 repeat array, being either normal or FSHD sized. These clones retain their myogenic characteristics, and D4Z4 contracted clones differ from the noncontracted clones by the bursts of expression of DUX4 in sporadic nuclei, showing that this burst-like phenomenon is a locus-intrinsic feature. Consequently, downstream effects of DUX4 expression can be observed in D4Z4 contracted clones, like differential expression of DUX4 target genes. We also show their participation to in vivo regeneration with immunodeficient mice, further expanding the potential of these clones for mechanistic and therapeutic studies. These cell lines will facilitate pairwise comparisons to identify FSHD-specific differences and are expected to create new opportunities for high-throughput drug screens.

  16. Integrated models to support multiobjective ecological restoration decisions.

    PubMed

    Fraser, Hannah; Rumpff, Libby; Yen, Jian D L; Robinson, Doug; Wintle, Brendan A

    2017-03-24

    Many objectives motivate ecological restoration including improving vegetation condition, increasing the range and abundance of threatened species, and improving aggregate measures of biodiversity such as richness and diversity. While ecological models have been used to examine the outcomes of ecological restoration, there are few attempts to develop models to account for multiple, potentially competing objectives. We develop the first predictive model that integrates a vegetation-focused state-and-transition model with species distribution models for birds. We demonstrate how this integrated model can be used to identify effective restoration options for vegetation and bird species under a constrained budget. For example, using a typical agricultural land management scenario from south-eastern Australia, we demonstrate how the optimal management actions for promoting the occurrence of the Brown Treecreeper, an iconic threatened species, may be suboptimal for meeting vegetation condition objectives. This highlights that any 'preferred' management decision depends on the value assigned to the different objectives. An exploration of sensitivity to value weightings highlighted that 'no management' or 'weed control' were most likely to be the best management options to meet multiple objectives in the scenario we explored. We thus illustrate an approach to using the model outputs to explore trade-offs between bird and vegetation objectives. Our approach to exploring management outcomes and trade-offs using integrated modelling and structured decision support approaches has wide application for conservation management problems in which trade-offs exist between competing objectives. This article is protected by copyright. All rights reserved.

  17. Dynamical mass modeling of dispersion-supported dwarf galaxies

    NASA Astrophysics Data System (ADS)

    Wolf, Joseph

    The currently favored cold dark matter cosmology (LCDM) has had much success in reproducing the large scale structure of the universe. However, on smaller scales there are some possible discrepancies when attempting to match galactic observations with properties of halos in dissipationless LCDM simulations. One advantageous method to test small scale simulations with observations is through dynamical mass modeling of nearby dwarf spheroidal galaxies (dSphs). The stellar tracers of dSphs are dispersion-supported, which poses a significant challenge in accurately deriving mass profiles. Unlike rotationally-supported galaxies, the dynamics of which can be well-approximated by one-dimensional physics, modeling dispersion-supported systems given only line-of-sight data results in a well-known degeneracy between the mass profile and the velocity dispersion anisotropy. The core of this dissertation is rooted in a new advancement which we have discovered: the range of solutions allowed by the mass-anisotropy degeneracy varies as a function of radius, with a considerable minimal near the deprojected half-light radius of almost all observed dispersion-supported galaxies. This finding allows for a wide range of applications in galaxy formation scenarios to be explored in an attempt to address, amongst other hypotheses, whether the LCDM framework needs to be modified in order to reproduce observations on the small scale. This thesis is comprised of both the derivation of this finding, and its applicability to all dispersion-supported systems, ranging from dwarfs galaxies consisting of a few hundred stars to systems of 'intracluster light', containing over a trillion stars. Rarely does one have the privilege of working with systems that span such a large range in luminosity (or any intrinsic property) in a short graduate career. Although the large applicability of this scale-free finding allows for discussion in many subfields, this thesis will mainly focus on one topic: dwarf

  18. Experimental Permeability Measurements on a Strut-Supported Transpiration-Cooled Turbine Blade with Stainless-Steel Shell made by the Federal-Mogul Corporation under Bureau of Aeronautics Contract N0as 51613-C

    NASA Technical Reports Server (NTRS)

    Richards, Hadley T.

    1954-01-01

    A turbine blade with a porous stainless-steel shell sintered to a supporting steel strut has been fabricated for tests at the NACA by Federal-Mogul Corporation under contract from the Bureau of Aeronautics, Department of the Navy. The apparent permeability of this blade, on the average, more nearly approaches the values specified by the NAGA than did two strut-supported bronze blades in a previous investigation. Random variations of permeability in the present blade are substantialy greater than those of the bronze blades, but projected improvements in certain phases of the fabrication process are expected to reduce these variations.

  19. Commerical Remote Sensing Data Contract

    USGS Publications Warehouse

    ,

    2005-01-01

    The U. S. Geological Survey's (USGS) Commercial Remote Sensing Data Contracts (CRSDCs) provide government agencies with access to a broad range of commercially available remotely sensed airborne and satellite data. These contracts were established to support The National Map partners, other Federal Civilian agency programs, and Department of Defense programs that require data for the United States and its territories. Experience shows that centralized procurement of remotely sensed data leads to considerable cost savings to the Federal government through volume discounts, reduction of redundant contract administrative costs, and avoidance of duplicate purchases. These contracts directly support the President's Commercial Remote Sensing Space Policy, signed in 2003, by providing a centralized mechanism for civil agencies to acquire commercial remote sensing products to support their mission needs in an efficient and coordinated way. CRSDC administration is provided by the USGS Mid-Continent Mapping Center in Rolla, Missouri.

  20. A Model of the Effects of Perceived Parent and Peer Support on Adolescent False Self Behavior.

    ERIC Educational Resources Information Center

    Harter, Susan; And Others

    1996-01-01

    Hypothesized a model linking three perceived support variables--level of support, quality of support, and hope about future support--to false self-behaviors (not the "real me"). The best fitting model for the parent and peer data revealed that perceived quality and level of parental support predicted hope about future parental support,…

  1. Small and large animal models in cardiac contraction research: advantages and disadvantages.

    PubMed

    Milani-Nejad, Nima; Janssen, Paul M L

    2014-03-01

    The mammalian heart is responsible for not only pumping blood throughout the body but also adjusting this pumping activity quickly depending upon sudden changes in the metabolic demands of the body. For the most part, the human heart is capable of performing its duties without complications; however, throughout many decades of use, at some point this system encounters problems. Research into the heart's activities during healthy states and during adverse impacts that occur in disease states is necessary in order to strategize novel treatment options to ultimately prolong and improve patients' lives. Animal models are an important aspect of cardiac research where a variety of cardiac processes and therapeutic targets can be studied. However, there are differences between the heart of a human being and an animal and depending on the specific animal, these differences can become more pronounced and in certain cases limiting. There is no ideal animal model available for cardiac research, the use of each animal model is accompanied with its own set of advantages and disadvantages. In this review, we will discuss these advantages and disadvantages of commonly used laboratory animals including mouse, rat, rabbit, canine, swine, and sheep. Since the goal of cardiac research is to enhance our understanding of human health and disease and help improve clinical outcomes, we will also discuss the role of human cardiac tissue in cardiac research. This review will focus on the cardiac ventricular contractile and relaxation kinetics of humans and animal models in order to illustrate these differences.

  2. Hand-Held Model of a Sarcomere to Illustrate the Sliding Filament Mechanism in Muscle Contraction

    ERIC Educational Resources Information Center

    Jittivadhna, Karnyupha; Ruenwongsa, Pintip; Panijpan, Bhinyo

    2009-01-01

    From our teaching of the contractile unit of the striated muscle, we have found limitations in using textbook illustrations of sarcomere structure and its related dynamic molecular physiological details. A hand-held model of a striated muscle sarcomere made from common items has thus been made by us to enhance students' understanding of the…

  3. Small and Large Animal Models in Cardiac Contraction Research: Advantages and Disadvantages

    PubMed Central

    Milani-Nejad, Nima; Janssen, Paul M.L.

    2013-01-01

    The mammalian heart is responsible for not only pumping blood throughout the body but also adjusting this pumping activity quickly depending upon sudden changes in the metabolic demands of the body. For the most part, the human heart is capable of performing its duties without complications; however, throughout many decades of use, at some point this system encounters problems. Research into the heart’s activities during healthy states and during adverse impacts that occur in disease states is necessary in order to strategize novel treatment options to ultimately prolong and improve patients’ lives. Animal models are an important aspect of cardiac research where a variety of cardiac processes and therapeutic targets can be studied. However, there are differences between the heart of a human being and an animal and depending on the specific animal, these differences can become more pronounced and in certain cases limiting. There is no ideal animal model available for cardiac research, the use of each animal model is accompanied with its own set of advantages and disadvantages. In this review, we will discuss these advantages and disadvantages of commonly used laboratory animals including mouse, rat, rabbit, canine, swine, and sheep. Since the goal of cardiac research is to enhance our understanding of human health and disease and help improve clinical outcomes, we will also discuss the role of human cardiac tissue in cardiac research. This review will focus on the cardiac ventricular contractile and relaxation kinetics of humans and animal models in order to illustrate these differences. PMID:24140081

  4. Modeling active muscle contraction in mitral valve leaflets during systole: a first approach.

    PubMed

    Skallerud, B; Prot, V; Nordrum, I S

    2011-02-01

    The present study addresses the effect of muscle activation contributions to mitral valve leaflet response during systole. State-of-art passive hyperelastic material modeling is employed in combination with a simple active stress part. Fiber families are assumed in the leaflets: one defined by the collagen and one defined by muscle activation. The active part is either assumed to be orthogonal to the collagen fibers or both orthogonal to and parallel with the collagen fibers (i.e. an orthotropic muscle fiber model). Based on data published in the literature and information herein on morphology, the size of the leaflet parts that contain muscle fibers is estimated. These parts have both active and passive materials, the remaining parts consist of passive material only. Several solid finite element analyses with different maximum activation levels are run. The simulation results are compared to corresponding echocardiography at peak systole for a porcine model. The physiologically correct flat shape of the closed valve is approached as the activation levels increase. The non-physiological bulging of the leaflet into the left atrium when using passive material models is reduced significantly. These results contribute to improved understanding of the physiology of the native mitral valve, and add evidence to the hypothesis that the mitral valve leaflets not are just passive elements moving as a result of hemodynamic pressure gradients in the left part of the heart.

  5. Predicting Effects of Tropomyosin Mutations on Cardiac Muscle Contraction through Myofilament Modeling

    PubMed Central

    Sewanan, Lorenzo R.; Moore, Jeffrey R.; Lehman, William; Campbell, Stuart G.

    2016-01-01

    Point mutations to the human gene TPM1 have been implicated in the development of both hypertrophic and dilated cardiomyopathies. Such observations have led to studies investigating the link between single residue changes and the biophysical behavior of the tropomyosin molecule. However, the degree to which these molecular perturbations explain the performance of intact sarcomeres containing mutant tropomyosin remains uncertain. Here, we present a modeling approach that integrates various aspects of tropomyosin's molecular properties into a cohesive paradigm representing their impact on muscle function. In particular, we considered the effects of tropomyosin mutations on (1) persistence length, (2) equilibrium between thin filament blocked and closed regulatory states, and (3) the crossbridge duty cycle. After demonstrating the ability of the new model to capture Ca-dependent myofilament responses during both dynamic and steady-state activation, we used it to capture the effects of hypertrophic cardiomyopathy (HCM) related E180G and D175N mutations on skinned myofiber mechanics. Our analysis indicates that the fiber-level effects of the two mutations can be accurately described by a combination of changes to the three tropomyosin properties represented in the model. Subsequently, we used the model to predict mutation effects on muscle twitch. Both mutations led to increased twitch contractility as a consequence of diminished cooperative inhibition between thin filament regulatory units. Overall, simulations suggest that a common twitch phenotype for HCM-linked tropomyosin mutations includes both increased contractility and elevated diastolic tension. PMID:27833562

  6. Hand-Held Model of a Sarcomere to Illustrate the Sliding Filament Mechanism in Muscle Contraction

    ERIC Educational Resources Information Center

    Jittivadhna, Karnyupha; Ruenwongsa, Pintip; Panijpan, Bhinyo

    2009-01-01

    From our teaching of the contractile unit of the striated muscle, we have found limitations in using textbook illustrations of sarcomere structure and its related dynamic molecular physiological details. A hand-held model of a striated muscle sarcomere made from common items has thus been made by us to enhance students' understanding of the…

  7. 7 CFR Appendix A to Subpart C of... - Model Form of Loan Contract for Electric Distribution Borrowers

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... business. (m) Survival. All representations and warranties made by the Borrower herein or made in any... the Flood Insurance Act and any Rules. (m) Compliance With Loan Contract and Mortgage. That the...) years if the kWh sales or kW demand for any year covered by such contract shall exceed 25 percent of...

  8. Modeling science: Supporting a more authentic epistemology of science

    NASA Astrophysics Data System (ADS)

    Svoboda, Julia Marie

    In this dissertation I argue that model-based inquiry has the potential to create experiences for students to consider how scientific knowledge is generated and evaluated - that is, for students to consider the epistemology of science. I also argue that such epistemically rich experiences can lead to shifts in students' conceptions of the nature of scientific knowledge. The context of this work is a yearlong biological modeling traineeship for undergraduate mathematics and biology majors called Collaborative Learning at the Interface of Mathematics and Biology (CLIMB). I used an ethnographically-based approach to collect detailed field notes, video, documents and interviews with faculty and students in CLIMB. The resulting dataset provides a rich description of the CLIMB program as well as students experiences in this program. Analysis of the CLIMB curriculum revealed that the degree to which students were treated as independent scholars and challenged with authentic problems influenced the productivity of their activity. A more detailed analysis of the nature of modeling tasks revealed that only when models were at the center of their activity did students have opportunities to consider epistemic themes relating to how knowledge is created and critiqued in science. Finally, a case study that followed a single student described how rich epistemically rich experiences with modeling have the potential to shift the ways in which students conceive of scientific knowledge and practice. It also provided evidence that supports the theory that students have complex multidimensional epistemic ecologies as opposed to static views about science. As a whole, this dissertation provides a rich description of how model-based inquiry can support learning about the epistemology of science and suggests that scientific modeling should have a more central role in science education.

  9. Operations and support cost modeling using Markov chains

    NASA Technical Reports Server (NTRS)

    Unal, Resit

    1989-01-01

    Systems for future missions will be selected with life cycle costs (LCC) as a primary evaluation criterion. This reflects the current realization that only systems which are considered affordable will be built in the future due to the national budget constaints. Such an environment calls for innovative cost modeling techniques which address all of the phases a space system goes through during its life cycle, namely: design and development, fabrication, operations and support; and retirement. A significant portion of the LCC for reusable systems are generated during the operations and support phase (OS). Typically, OS costs can account for 60 to 80 percent of the total LCC. Clearly, OS costs are wholly determined or at least strongly influenced by decisions made during the design and development phases of the project. As a result OS costs need to be considered and estimated early in the conceptual phase. To be effective, an OS cost estimating model needs to account for actual instead of ideal processes by associating cost elements with probabilities. One approach that may be suitable for OS cost modeling is the use of the Markov Chain Process. Markov chains are an important method of probabilistic analysis for operations research analysts but they are rarely used for life cycle cost analysis. This research effort evaluates the use of Markov Chains in LCC analysis by developing OS cost model for a hypothetical reusable space transportation vehicle (HSTV) and suggests further uses of the Markov Chain process as a design-aid tool.

  10. Mimetic butterflies support Wallace's model of sexual dimorphism.

    PubMed

    Kunte, Krushnamegh

    2008-07-22

    Theoretical and empirical observations generally support Darwin's view that sexual dimorphism evolves due to sexual selection on, and deviation in, exaggerated male traits. Wallace presented a radical alternative, which is largely untested, that sexual dimorphism results from naturally selected deviation in protective female coloration. This leads to the prediction that deviation in female rather than male phenotype causes sexual dimorphism. Here I test Wallace's model of sexual dimorphism by tracing the evolutionary history of Batesian mimicry-an example of naturally selected protective coloration-on a molecular phylogeny of Papilio butterflies. I show that sexual dimorphism in Papilio is significantly correlated with both female-limited Batesian mimicry, where females are mimetic and males are non-mimetic, and with the deviation of female wing colour patterns from the ancestral patterns conserved in males. Thus, Wallace's model largely explains sexual dimorphism in Papilio. This finding, along with indirect support from recent studies on birds and lizards, suggests that Wallace's model may be more widely useful in explaining sexual dimorphism. These results also highlight the contribution of naturally selected female traits in driving phenotypic divergence between species, instead of merely facilitating the divergence in male sexual traits as described by Darwin's model.

  11. A prototype computer-aided modelling tool for life-support system models

    NASA Technical Reports Server (NTRS)

    Preisig, H. A.; Lee, Tae-Yeong; Little, Frank

    1990-01-01

    Based on the canonical decomposition of physical-chemical-biological systems, a prototype kernel has been developed to efficiently model alternative life-support systems. It supports (1) the work in an interdisciplinary group through an easy-to-use mostly graphical interface, (2) modularized object-oriented model representation, (3) reuse of models, (4) inheritance of structures from model object to model object, and (5) model data base. The kernel is implemented in Modula-II and presently operates on an IBM PC.

  12. A Model for Sustainable Building Energy Efficiency Retrofit (BEER) Using Energy Performance Contracting (EPC) Mechanism for Hotel Buildings in China

    NASA Astrophysics Data System (ADS)

    Xu, Pengpeng

    Hotel building is one of the high-energy-consuming building types, and retrofitting hotel buildings is an untapped solution to help cut carbon emissions contributing towards sustainable development. Energy Performance Contracting (EPC) has been promulgated as a market mechanism for the delivery of energy efficiency projects. EPC mechanism has been introduced into China relatively recently, and it has not been implemented successfully in building energy efficiency retrofit projects. The aim of this research is to develop a model for achieving the sustainability of Building Energy Efficiency Retrofit (BEER) in hotel buildings under the Energy Performance Contracting (EPC) mechanism. The objectives include: • To identify a set of Key Performance Indicators (KPIs) for measuring the sustainability of BEER in hotel buildings; • To identify Critical Success Factors (CSFs) under EPC mechanism that have a strong correlation with sustainable BEER project; • To develop a model explaining the relationships between the CSFs and the sustainability performance of BEER in hotel building. Literature reviews revealed the essence of sustainable BEER and EPC, which help to develop a conceptual framework for analyzing sustainable BEER under EPC mechanism in hotel buildings. 11 potential KPIs for sustainable BEER and 28 success factors of EPC were selected based on the developed framework. A questionnaire survey was conducted to ascertain the importance of selected performance indicators and success factors. Fuzzy set theory was adopted in identifying the KPIs. Six KPIs were identified from the 11 selected performance indicators. Through a questionnaire survey, out of the 28 success factors, 21 Critical Success Factors (CSFs) were also indentified. Using the factor analysis technique, the 21 identified CSFs in this study were grouped into six clusters to help explain project success of sustainable BEER. Finally, AHP/ANP approach was used in this research to develop a model to

  13. Job Demands-Control-Support model and employee safety performance.

    PubMed

    Turner, Nick; Stride, Chris B; Carter, Angela J; McCaughey, Deirdre; Carroll, Anthony E

    2012-03-01

    The aim of this study was to explore whether work characteristics (job demands, job control, social support) comprising Karasek and Theorell's (1990) Job Demands-Control-Support framework predict employee safety performance (safety compliance and safety participation; Neal and Griffin, 2006). We used cross-sectional data of self-reported work characteristics and employee safety performance from 280 healthcare staff (doctors, nurses, and administrative staff) from Emergency Departments of seven hospitals in the United Kingdom. We analyzed these data using a structural equation model that simultaneously regressed safety compliance and safety participation on the main effects of each of the aforementioned work characteristics, their two-way interactions, and the three-way interaction among them, while controlling for demographic, occupational, and organizational characteristics. Social support was positively related to safety compliance, and both job control and the two-way interaction between job control and social support were positively related to safety participation. How work design is related to employee safety performance remains an important area for research and provides insight into how organizations can improve workplace safety. The current findings emphasize the importance of the co-worker in promoting both safety compliance and safety participation.

  14. Bridging groundwater models and decision support with a Bayesian network

    USGS Publications Warehouse

    Fienen, Michael N.; Masterson, John P.; Plant, Nathaniel G.; Gutierrez, Benjamin T.; Thieler, E. Robert

    2013-01-01

    Resource managers need to make decisions to plan for future environmental conditions, particularly sea level rise, in the face of substantial uncertainty. Many interacting processes factor in to the decisions they face. Advances in process models and the quantification of uncertainty have made models a valuable tool for this purpose. Long-simulation runtimes and, often, numerical instability make linking process models impractical in many cases. A method for emulating the important connections between model input and forecasts, while propagating uncertainty, has the potential to provide a bridge between complicated numerical process models and the efficiency and stability needed for decision making. We explore this using a Bayesian network (BN) to emulate a groundwater flow model. We expand on previous approaches to validating a BN by calculating forecasting skill using cross validation of a groundwater model of Assateague Island in Virginia and Maryland, USA. This BN emulation was shown to capture the important groundwater-flow characteristics and uncertainty of the groundwater system because of its connection to island morphology and sea level. Forecast power metrics associated with the validation of multiple alternative BN designs guided the selection of an optimal level of BN complexity. Assateague island is an ideal test case for exploring a forecasting tool based on current conditions because the unique hydrogeomorphological variability of the island includes a range of settings indicative of past, current, and future conditions. The resulting BN is a valuable tool for exploring the response of groundwater conditions to sea level rise in decision support.

  15. Intrinsic bioremediation modeling to support Superfund site closure

    SciTech Connect

    Bedard, A.H.; Day, M.J.; Johnson, R.H.; Ritter, K.J.; Stancel, S.G.; Thomson, J.A.M.

    1997-09-01

    Closure of the groundwater component of a major Superfund site has been accomplished by a combination of source control, engineered in-situ bioremediation, and subsequent long-term intrinsic bioremediation. Engineered bioremediation outside the source control area resulted in very significant contaminant mass removal. This allowed intrinsic bioremediation to be considered as a passive remedial management method of achieving cleanup objectives after active remediation needed. Modeling demonstrated that intrinsic bioremediation would achieve cleanup objectives (for this site, Federal drinking water standards) within ten years of shutdown of the active bioremediation system. Modeling showed that residual electron acceptors and nutrients distributed in the aquifer during engineered bioremediation greatly enhance the intrinsic bioremediation process. The results of the modeling effort led to the active system being shut down a year ahead of schedule, allowing the project to move into a low-maintenance intrinsic bioremediation and long-term monitoring phase. The modeling demonstration coupled Visual MODFLOW{copyright} and BioTrans{copyright} to simulate groundwater flow, solute transport, and oxygen-limited, multi-species biodegradation. Regional flow evaluation, detailed model sensitivity analyses, and subarea modeling were employed to provide support to model predictions. Predictions will be tested by subsequent progress and compliance monitoring. Site closure began in early 1996.

  16. Bridging groundwater models and decision support with a Bayesian network

    NASA Astrophysics Data System (ADS)

    Fienen, Michael N.; Masterson, John P.; Plant, Nathaniel G.; Gutierrez, Benjamin T.; Thieler, E. Robert

    2013-10-01

    Resource managers need to make decisions to plan for future environmental conditions, particularly sea level rise, in the face of substantial uncertainty. Many interacting processes factor in to the decisions they face. Advances in process models and the quantification of uncertainty have made models a valuable tool for this purpose. Long-simulation runtimes and, often, numerical instability make linking process models impractical in many cases. A method for emulating the important connections between model input and forecasts, while propagating uncertainty, has the potential to provide a bridge between complicated numerical process models and the efficiency and stability needed for decision making. We explore this using a Bayesian network (BN) to emulate a groundwater flow model. We expand on previous approaches to validating a BN by calculating forecasting skill using cross validation of a groundwater model of Assateague Island in Virginia and Maryland, USA. This BN emulation was shown to capture the important groundwater-flow characteristics and uncertainty of the groundwater system because of its connection to island morphology and sea level. Forecast power metrics associated with the validation of multiple alternative BN designs guided the selection of an optimal level of BN complexity. Assateague island is an ideal test case for exploring a forecasting tool based on current conditions because the unique hydrogeomorphological variability of the island includes a range of settings indicative of past, current, and future conditions. The resulting BN is a valuable tool for exploring the response of groundwater conditions to sea level rise in decision support.

  17. The European ALMA Regional Centre: a model of user support

    NASA Astrophysics Data System (ADS)

    Andreani, P.; Stoehr, F.; Zwaan, M.; Hatziminaoglou, E.; Biggs, A.; Diaz-Trigo, M.; Humphreys, E.; Petry, D.; Randall, S.; Stanke, T.; van Kampen, E.; Bárta, M.; Brand, J.; Gueth, F.; Hogerheijde, M.; Bertoldi, F.; Muxlow, T.; Richards, A.; Vlemmings, W.

    2014-08-01

    The ALMA Regional Centres (ARCs) form the interface between the ALMA observatory and the user community from the proposal preparation stage to the delivery of data and their subsequent analysis. The ARCs provide critical services to both the ALMA operations in Chile and to the user community. These services were split by the ALMA project into core and additional services. The core services are financed by the ALMA operations budget and are critical to the successful operation of ALMA. They are contractual obligations and must be delivered to the ALMA project. The additional services are not funded by the ALMA project and are not contractual obligations, but are critical to achieve ALMA full scientific potential. A distributed network of ARC nodes (with ESO being the central ARC) has been set up throughout Europe at the following seven locations: Bologna, Bonn-Cologne, Grenoble, Leiden, Manchester, Ondrejov, Onsala. These ARC nodes are working together with the central node at ESO and provide both core and additional services to the ALMA user community. This paper presents the European ARC, and how it operates in Europe to support the ALMA community. This model, although complex in nature, is turning into a very successful one, providing a service to the scientific community that has been so far highly appreciated. The ARC could become a reference support model in an age where very large collaborations are required to build large facilities, and support is needed for geographically and culturally diverse communities.

  18. A New ’Availability-Payment’ Model for Pricing Performance-Based Logistics Contracts

    DTIC Science & Technology

    2014-04-30

    which will ideally be close to zero after responding to demands in each period. The model involves the integration of the event- based structure... methods based on the theory of continuous-time Markov chains on a finite or countable infinite state space. DES is capable of representing the...bäÉîÉåíÜ=^ååì~ä=^Åèìáëáíáçå= oÉëÉ~êÅÜ=póãéçëáìã= tÉÇåÉëÇ~ó=pÉëëáçåë= sçäìãÉ=f= = A New “Availability-Payment” Model for Pricing Performance- Based

  19. Contraction Options and Optimal Multiple-Stopping in Spectrally Negative Lévy Models

    SciTech Connect

    Yamazaki, Kazutoshi

    2015-08-15

    This paper studies the optimal multiple-stopping problem arising in the context of the timing option to withdraw from a project in stages. The profits are driven by a general spectrally negative Lévy process. This allows the model to incorporate sudden declines of the project values, generalizing greatly the classical geometric Brownian motion model. We solve the one-stage case as well as the extension to the multiple-stage case. The optimal stopping times are of threshold-type and the value function admits an expression in terms of the scale function. A series of numerical experiments are conducted to verify the optimality and to evaluate the efficiency of the algorithm.

  20. The Coastal Modeling System: A System of Numerical Models and Support Programs

    DTIC Science & Technology

    1991-12-01

    via the Coastal Modeling System ( CMS ). The CMS is a software package aimed at organizing CERC’s larger numerical models and their supporting software...reduced because of user familiarity with the system structure. COMPONENTS: The CMS is a supercomputer-based system of models and supporting software...elevations from tidal constituent input. Generally, CMS users are not required to learn the JCL of the host computer system . Most of the job’control commands

  1. General KBE model with inheritance and multi CAD support

    NASA Astrophysics Data System (ADS)

    Tiuca, T. L.; Rusu, C.; Noveanu, S.; Mandru, D.

    2016-08-01

    Knowledge-Based Engineering (KBE) is a research field that studies methodologies and technologies for capture and re-use engineering knowledge. The primary objective of KBE is to reduce time and cost of product research processes and/or product development, which is primarily achieved through automation of repetitive design tasks while capturing, retaining and re-using engineering knowledge. Every CAD System includes KBE Tools. The power of these tools is incremented by the use of external high level programming language. The model presented in this paper has the aim to reduce times and costs of particular KBE Models development, by programming inheritance concepts and also the multi CAD Support. The model is implemented through a C# application that is also presented.

  2. Land Surface Emission Modeling to Support Physical Precipitation Retrievals

    NASA Technical Reports Server (NTRS)

    Peters-Lidard, Christina D.; Harrison, Kenneth; Kumar, Sujay; Ferraro, Ralph; Skofronick-Jackson, Gail

    2010-01-01

    Land surface modeling and data assimilation can provide dynamic land surface state variables necessary to support physical precipitation retrieval algorithms over land. It is well-known that surface emission, particularly over the range of frequencies to be included in the Global Precipitation Measurement Mission (GPM), is sensitive to land surface states, including soil properties, vegetation type and greenness, soil moisture, surface temperature, and snow cover, density, and grain size. In order to investigate the robustness of both the land surface model states and the microwave emissivity and forward radiative transfer models, we have undertaken a multi-site investigation as part of the NASA Precipitation Measurement Missions (PMM) Land Surface Characterization. Working Group.

  3. T:XML: A Tool Supporting User Interface Model Transformation

    NASA Astrophysics Data System (ADS)

    López-Jaquero, Víctor; Montero, Francisco; González, Pascual

    Model driven development of user interfaces is based on the transformation of an abstract specification into the final user interface the user will interact with. The design of transformation rules to carry out this transformation process is a key issue in any model-driven user interface development approach. In this paper, we introduce T:XML, an integrated development environment for managing, creating and previewing transformation rules. The tool supports the specification of transformation rules by using a graphical notation that works on the basis of the transformation of the input model into a graph-based representation. T:XML allows the design and execution of transformation rules in an integrated development environment. Furthermore, the designer can also preview how the generated user interface looks like after the transformations have been applied. These previewing capabilities can be used to quickly create prototypes to discuss with the users in user-centered design methods.

  4. Army Vessels Maintenance Contracts in Southwest Asia

    DTIC Science & Technology

    2010-05-21

    J&A Justification and Approval LSV Logistics Support Vessel-4 MARAV Master Agreement for Repair and Alteration of Vessels MICC-EU Mission and...Master Agreement for Repair and Alteration of Vessels ( MARAV ). Defense Federal Acquisition Regulations Supplement (DFARS) Subpart 217.71, “Master...that contains elements of a contract, but is not a contract. DFARS states that when soliciting for contracts issued under a MARAV , the contracting

  5. Inverse Modeling of Experiments to Support More Realistic Simulations of Sorbing Radionuclide Transport

    NASA Astrophysics Data System (ADS)

    Arnold, B. W.; James, S. C.; Reimus, P. W.

    2012-12-01

    A series of adsorption, desorption, and column transport experiments were conducted to evaluate the transport of uranium (U) and neptunium (Np) through saturated volcanic tuffs. For potential high-level radioactive waste sites, these experiments demonstrate that slow radionuclide desorption processes, which are typically not accounted for in transport models implementing simple partition coefficients (Kd values), may dominate field-scale transport. A complimentary interpretive numerical model couples a simplified geochemical description of the system with transport calculations where heterogeneities are represented as an ensemble of sorption sites with characteristic adsorption and desorption rate constants that have widely varying values. Adsorption and desorption rate constants were estimated through inverse modeling such that reliable upscaled predictions of reactive transport in field settings could be simulated. The inverse modeling software, PEST, was also used to perform advanced uncertainty quantification. The multicomponent model/parameters matching the combined data sets suggest that over much longer time and distance scales the transport of U and Np under the experimental conditions would result in very little transport over field scales because even a small number of strong sorption sites will have an exaggerated retarding influence on the transport of a radionuclide plume. Modeling of combined sorption/desorption experiments and column transport experiments that involve both the measurement of column effluent breakthrough curves and the distribution of radionuclides remaining in the column at the conclusion of the experiments holds significant promise for supporting an improved approach to properly account for mineralogical heterogeneity over long time and distance scales in reactive radionuclide transport models. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed

  6. Towards computational modeling of excitation-contraction coupling in cardiac myocytes: reconstruction of structures and proteins from confocal imaging.

    PubMed

    Sachse, Frank B; Savio-Galimberti, Eleonora; Goldhaber, Joshua I; Bridge, John H B

    2009-01-01

    Computational models of excitation-contraction (EC) coupling in myocytes are valuable tools for studying the signaling cascade that transduces transmembrane voltage into mechanical responses. A key component of these models is the appropriate description of structures involved in EC coupling, such as the sarcolemma and ion channels. This study aims at developing an approach for spatial reconstruction of these structures. We exemplified our approach by reconstructing clusters of ryanodine receptors (RyRs) together with the sarcolemma of rabbit ventricular myocytes. The reconstructions were based on dual labeling and three-dimensional (3D) confocal imaging of segments of fixed and permeabilized myocytes lying flat or on end. The imaging led to 3D stacks of cross-sections through myocytes. Methods of digital image processing were applied to deconvolve, filter and segment these stacks. Finally, we created point meshes representing RyR distributions together with volume and surface meshes of the sarcolemma. We suggest that these meshes are suitable for computational studies of structure-function relationships in EC coupling. We propose that this approach can be extended to reconstruct other structures and proteins involved in EC coupling.

  7. Emulation Modeling with Bayesian Networks for Efficient Decision Support

    NASA Astrophysics Data System (ADS)

    Fienen, M. N.; Masterson, J.; Plant, N. G.; Gutierrez, B. T.; Thieler, E. R.

    2012-12-01

    Bayesian decision networks (BDN) have long been used to provide decision support in systems that require explicit consideration of uncertainty; applications range from ecology to medical diagnostics and terrorism threat assessments. Until recently, however, few studies have applied BDNs to the study of groundwater systems. BDNs are particularly useful for representing real-world system variability by synthesizing a range of hydrogeologic situations within a single simulation. Because BDN output is cast in terms of probability—an output desired by decision makers—they explicitly incorporate the uncertainty of a system. BDNs can thus serve as a more efficient alternative to other uncertainty characterization methods such as computationally demanding Monte Carlo analyses and others methods restricted to linear model analyses. We present a unique application of a BDN to a groundwater modeling analysis of the hydrologic response of Assateague Island, Maryland to sea-level rise. Using both input and output variables of the modeled groundwater response to different sea-level (SLR) rise scenarios, the BDN predicts the probability of changes in the depth to fresh water, which exerts an important influence on physical and biological island evolution. Input variables included barrier-island width, maximum island elevation, and aquifer recharge. The variability of these inputs and their corresponding outputs are sampled along cross sections in a single model run to form an ensemble of input/output pairs. The BDN outputs, which are the posterior distributions of water table conditions for the sea-level rise scenarios, are evaluated through error analysis and cross-validation to assess both fit to training data and predictive power. The key benefit for using BDNs in groundwater modeling analyses is that they provide a method for distilling complex model results into predictions with associated uncertainty, which is useful to decision makers. Future efforts incorporate

  8. Distributed Hydrologic Modeling Apps for Decision Support in the Cloud

    NASA Astrophysics Data System (ADS)

    Swain, N. R.; Latu, K.; Christiensen, S.; Jones, N.; Nelson, J.

    2013-12-01

    Advances in computation resources and greater availability of water resources data represent an untapped resource for addressing hydrologic uncertainties in water resources decision-making. The current practice of water authorities relies on empirical, lumped hydrologic models to estimate watershed response. These models are not capable of taking advantage of many of the spatial datasets that are now available. Physically-based, distributed hydrologic models are capable of using these data resources and providing better predictions through stochastic analysis. However, there exists a digital divide that discourages many science-minded decision makers from using distributed models. This divide can be spanned using a combination of existing web technologies. The purpose of this presentation is to present a cloud-based environment that will offer hydrologic modeling tools or 'apps' for decision support and the web technologies that have been selected to aid in its implementation. Compared to the more commonly used lumped-parameter models, distributed models, while being more intuitive, are still data intensive, computationally expensive, and difficult to modify for scenario exploration. However, web technologies such as web GIS, web services, and cloud computing have made the data more accessible, provided an inexpensive means of high-performance computing, and created an environment for developing user-friendly apps for distributed modeling. Since many water authorities are primarily interested in the scenario exploration exercises with hydrologic models, we are creating a toolkit that facilitates the development of a series of apps for manipulating existing distributed models. There are a number of hurdles that cloud-based hydrologic modeling developers face. One of these is how to work with the geospatial data inherent with this class of models in a web environment. Supporting geospatial data in a website is beyond the capabilities of standard web frameworks and it

  9. A new decision support model for preanesthetic evaluation.

    PubMed

    Sobrie, Olivier; Lazouni, Mohammed El Amine; Mahmoudi, Saïd; Mousseau, Vincent; Pirlot, Marc

    2016-09-01

    The principal challenges in the field of anesthesia and intensive care consist of reducing both anesthetic risks and mortality rate. The ASA score plays an important role in patients' preanesthetic evaluation. In this paper, we propose a methodology to derive simple rules which classify patients in a category of the ASA scale on the basis of their medical characteristics. This diagnosis system is based on MR-Sort, a multiple criteria decision analysis model. The proposed method intends to support two steps in this process. The first is the assignment of an ASA score to the patient; the second concerns the decision to accept-or not-the patient for surgery. In order to learn the model parameters and assess its effectiveness, we use a database containing the parameters of 898 patients who underwent preanesthesia evaluation. The accuracy of the learned models for predicting the ASA score and the decision of accepting the patient for surgery is assessed and proves to be better than that of other machine learning methods. Furthermore, simple decision rules can be explicitly derived from the learned model. These are easily interpretable by doctors, and their consistency with medical knowledge can be checked. The proposed model for assessing the ASA score produces accurate predictions on the basis of the (limited) set of patient attributes in the database available for the tests. Moreover, the learned MR-Sort model allows for easy interpretation by providing human-readable classification rules. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. A Navigation Safety Support Model for the Strait of Istanbul

    NASA Astrophysics Data System (ADS)

    Yazici, M. Anil; Otay, Emre N.

    In this study, a real time maritime traffic support model is developed for safe navigation in the Strait of Istanbul, also known as the Bosporus. The present model simulates vessel trajectories corresponding to possible headings, using channel geometry, counter traffic, and surface currents as input. A new MATLAB code is developed for the simulation and the Marine GNC Toolbox (Fossen and Perez, 2004) is used for the vessel hydrodynamics and the auto-pilot model. After computing the trajectory tree of the vessel by forward-mapping its position distribution with respect to the initial position vector, the casualty probabilities of each trajectory are found. Within certain restrictions on vessel geometry, the proposed model predicts the safest possible intended course for the transit vessels based on the navigational parameters including position, speed, and course of the vessel. The model is tested for the Strait of Istanbul for validation. Without loss of generality, the model can be used for any narrow channel with a vessel traffic system providing the necessary input.

  11. Fuzzy Naive Bayesian model for medical diagnostic decision support.

    PubMed

    Wagholikar, Kavishwar B; Vijayraghavan, Sundararajan; Deshpande, Ashok W

    2009-01-01

    This work relates to the development of computational algorithms to provide decision support to physicians. The authors propose a Fuzzy Naive Bayesian (FNB) model for medical diagnosis, which extends the Fuzzy Bayesian approach proposed by Okuda. A physician's interview based method is described to define a orthogonal fuzzy symptom information system, required to apply the model. For the purpose of elaboration and elicitation of characteristics, the algorithm is applied to a simple simulated dataset, and compared with conventional Naive Bayes (NB) approach. As a preliminary evaluation of FNB in real world scenario, the comparison is repeated on a real fuzzy dataset of 81 patients diagnosed with infectious diseases. The case study on simulated dataset elucidates that FNB can be optimal over NB for diagnosing patients with imprecise-fuzzy information, on account of the following characteristics - 1) it can model the information that, values of some attributes are semantically closer than values of other attributes, and 2) it offers a mechanism to temper exaggerations in patient information. Although the algorithm requires precise training data, its utility for fuzzy training data is argued for. This is supported by the case study on infectious disease dataset, which indicates optimality of FNB over NB for the infectious disease domain. Further case studies on large datasets are required to establish utility of FNB.

  12. CORHEL MHD Modeling in Support of Solar Dynamics Observatory

    NASA Astrophysics Data System (ADS)

    Linker, Jon A.; Riley, P.; Mikic, Z.; Lionello, R.; Titov, V.; Wijaya, J.

    2010-05-01

    CORHEL - for Corona-Heliosphere - is a coupled set of models and tools for quantitatively modeling the ambient solar corona and solar wind in various approximations. The coronal MHD code MAS in CORHEL has been used to produce routine polytropic solutions for all of the Carrington rotations during the STEREO mission (available at www.predsci.com). The MAS code can also be used to produce solutions that include energy transport (radiative losses, anisotropic thermal conduction, and coronal heating) in the transition region and solar corona. This more accurate representation of energy flow allows us to compute simulated EUV and X-ray emission and compare directly with observations. We refer to this as the thermodynamic MHD model. In this paper, we describe the production of thermodynamic MHD solutions as part of CORHEL. When sufficiently calibrated data are available, the solutions will use magnetic maps derived from HMI magnetograms. These solutions will be made routinely available in support of the Solar Dynamics Observatory (SDO) mission, and will allow comparison with emission observations from AIA when emission kernels become available. Work supported by the LWS Strategic Capabilities Program (NASA, NSF, and AFOSR), CISM (NSF), HTP (NASA) and the HMI team.

  13. Received and perceived social support in times of stress: a test of the social support deterioration deterrence model.

    PubMed

    Norris, F H; Kaniasty, K

    1996-09-01

    The authors evaluated the impact of receiving social support on subsequent levels of perceived social support and psychological distress in 2 independent samples of victims of severe natural disasters: Hurricane Hugo (n = 498) and Hurricane Andrew (n = 404). A social support deterioration deterrence model was proposed that stipulated that postdisaster mobilization of received support counteracts the deterioration in expectations of support often experienced by victims of major life events. LISREL analyses of data collected 12 and 24 months after Hugo and 6 and 28 months after Andrew provided strong evidence for the hypothesized model: Perceived support mediated the long-term effects on distress of both scope of disaster exposure and postdisaster received support. Theoretical and application issues of social support are discussed.

  14. Web-video-mining-supported workflow modeling for laparoscopic surgeries.

    PubMed

    Liu, Rui; Zhang, Xiaoli; Zhang, Hao

    2016-11-01

    As quality assurance is of strong concern in advanced surgeries, intelligent surgical systems are expected to have knowledge such as the knowledge of the surgical workflow model (SWM) to support their intuitive cooperation with surgeons. For generating a robust and reliable SWM, a large amount of training data is required. However, training data collected by physically recording surgery operations is often limited and data collection is time-consuming and labor-intensive, severely influencing knowledge scalability of the surgical systems. The objective of this research is to solve the knowledge scalability problem in surgical workflow modeling with a low cost and labor efficient way. A novel web-video-mining-supported surgical workflow modeling (webSWM) method is developed. A novel video quality analysis method based on topic analysis and sentiment analysis techniques is developed to select high-quality videos from abundant and noisy web videos. A statistical learning method is then used to build the workflow model based on the selected videos. To test the effectiveness of the webSWM method, 250 web videos were mined to generate a surgical workflow for the robotic cholecystectomy surgery. The generated workflow was evaluated by 4 web-retrieved videos and 4 operation-room-recorded videos, respectively. The evaluation results (video selection consistency n-index ≥0.60; surgical workflow matching degree ≥0.84) proved the effectiveness of the webSWM method in generating robust and reliable SWM knowledge by mining web videos. With the webSWM method, abundant web videos were selected and a reliable SWM was modeled in a short time with low labor cost. Satisfied performances in mining web videos and learning surgery-related knowledge show that the webSWM method is promising in scaling knowledge for intelligent surgical systems. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Mass balances for a biological life support system simulation model

    NASA Technical Reports Server (NTRS)

    Volk, Tyler; Rumel, John D.

    1987-01-01

    Design decisions to aid the development of future space-based biological life support systems (BLSS) can be made with simulation models. Here the biochemical stoichiometry is developed for: (1) protein, carbohydrate, fat, fiber, and lignin production in the edible and inedible parts of plants; (2) food consumption and production of organic solids in urine, feces, and wash water by the humans; and (3) operation of the waste processor. Flux values for all components are derived for a steady-state system with wheat as the sole food source.

  16. Mass balances for a biological life support system simulation model

    NASA Technical Reports Server (NTRS)

    Volk, Tyler; Rumel, John D.

    1987-01-01

    Design decisions to aid the development of future space-based biological life support systems (BLSS) can be made with simulation models. Here the biochemical stoichiometry is developed for: (1) protein, carbohydrate, fat, fiber, and lignin production in the edible and inedible parts of plants; (2) food consumption and production of organic solids in urine, feces, and wash water by the humans; and (3) operation of the waste processor. Flux values for all components are derived for a steady-state system with wheat as the sole food source.

  17. Computational Science Research in Support of Petascale Electromagnetic Modeling

    SciTech Connect

    Lee, L.-Q.; Akcelik, V; Ge, L; Chen, S; Schussman, G; Candel, A; Li, Z; Xiao, L; Kabel, A; Uplenchwar, R; Ng, C; Ko, K; /SLAC

    2008-06-20

    Computational science research components were vital parts of the SciDAC-1 accelerator project and are continuing to play a critical role in newly-funded SciDAC-2 accelerator project, the Community Petascale Project for Accelerator Science and Simulation (ComPASS). Recent advances and achievements in the area of computational science research in support of petascale electromagnetic modeling for accelerator design analysis are presented, which include shape determination of superconducting RF cavities, mesh-based multilevel preconditioner in solving highly-indefinite linear systems, moving window using h- or p- refinement for time-domain short-range wakefield calculations, and improved scalable application I/O.

  18. Advancing LGBT Elder Policy and Support Services: The Massachusetts Model.

    PubMed

    Krinsky, Lisa; Cahill, Sean

    2017-04-04

    The Massachusetts-based LGBT Aging Project has trained elder service providers in affirming and culturally competent care for LGBT older adults, supported development of LGBT-friendly meal programs, and advanced LGBT equality under aging policy. Working across sectors, this innovative model launched the country's first statewide Legislative Commission on Lesbian, Gay, Bisexual, and Transgender Aging. Advocates are working with policymakers to implement key recommendations, including cultural competency training and data collection in statewide networks of elder services. The LGBT Aging Project's success provides a template for improving services and policy for LGBT older adults throughout the country.

  19. Models for Deploying Open Source and Commercial Software to Support Earth Science Data Processing and Distribution

    NASA Astrophysics Data System (ADS)

    Yetman, G.; Downs, R. R.

    2011-12-01

    Software deployment is needed to process and distribute scientific data throughout the data lifecycle. Developing software in-house can take software development teams away from other software development projects and can require efforts to maintain the software over time. Adopting and reusing software and system modules that have been previously developed by others can reduce in-house software development and maintenance costs and can contribute to the quality of the system being developed. A variety of models are available for reusing and deploying software and systems that have been developed by others. These deployment models include open source software, vendor-supported open source software, commercial software, and combinations of these approaches. Deployment in Earth science data processing and distribution has demonstrated the advantages and drawbacks of each model. Deploying open source software offers advantages for developing and maintaining scientific data processing systems and applications. By joining an open source community that is developing a particular system module or application, a scientific data processing team can contribute to aspects of the software development without having to commit to developing the software alone. Communities of interested developers can share the work while focusing on activities that utilize in-house expertise and addresses internal requirements. Maintenance is also shared by members of the community. Deploying vendor-supported open source software offers similar advantages to open source software. However, by procuring the services of a vendor, the in-house team can rely on the vendor to provide, install, and maintain the software over time. Vendor-supported open source software may be ideal for teams that recognize the value of an open source software component or application and would like to contribute to the effort, but do not have the time or expertise to contribute extensively. Vendor-supported software may

  20. Systems Integration, Analysis and Modeling Support to the HEDS Technology/Commercialization Initiative (HTCI)

    NASA Technical Reports Server (NTRS)

    Feingold, Harvey; ONeil, Dan (Technical Monitor)

    2002-01-01

    In response to a recommendation from OMB, NASA's Fiscal Year 2001 budget included a new program within the HEDS (Human Exploration and Development of Space) Enterprise called HEDS Technology/ Commercialization Initiative (HTCI). HTCI had three overarching goals: to support REDS analysis and planning for safe, affordable and effective future programs and projects that advance human exploration, scientific discovery, and the commercial development of space; to pursue research, development, and validation of breakthrough technologies and highly innovative systems concepts; and to advance die creation of strong partnerships within NASA, with U.S. industry and universities, and internationally. As part of its contracted effort, SAIC was to write a report contribution, describing die results of its task activities, to a final HTCI report prepared by MSFC. Unfortunately, government cancellation of the HTCI program in the summer of 2001 curtailed all efforts on the program including die Final HTCI report. In the absence of that report, SAIC has issued this final report in an attempt to document some of the technical material it produced. The report contains SAIC presentations for both HTCI workshops; a set of roadmap charts for the Systems Analysis, Integration and Modeling; and charts showing the evolution of the current TITAN modeling architecture.

  1. Modelling and control of a rotor supported by magnetic bearings

    NASA Technical Reports Server (NTRS)

    Gurumoorthy, R.; Pradeep, A. K.

    1994-01-01

    In this paper we develop a dynamical model of a rotor and the active magnetic bearings used to support the rotor. We use this model to develop a stable state feedback control of the magnetic bearing system. We present the development of a rigid body model of the rotor, utilizing both Rotation Matrices (Euler Angles) and Euler Parameters (Quaternions). In the latter half of the paper we develop a stable state feedback control of the actively controlled magnetic bearing to control the rotor position under inbalances. The control law developed takes into account the variation of the model with rotational speed. We show stability over the whole operating range of speeds for the magnetic bearing system. Simulation results are presented to demonstrate the closed loop system performance. We develop the model of the magnetic bearing, and present two schemes for the excitation of the poles of the actively controlled magnetic bearing. We also present a scheme for averaging multiple sensor measurements and splitting the actuation forces amongst redundant actuators.

  2. Modeling the Jovian Magnetopause in Support of Juno

    NASA Astrophysics Data System (ADS)

    Masters, A.

    2016-12-01

    The magnetopause boundary of a planetary magnetosphere is the site of direct interaction between the solar wind and the planetary magnetic field. Processes that operate at such current sheets can break down the natural magnetic shielding of a planet, allowing solar wind energy into the system and potentially leading to auroral emissions. Global analytical modeling applied to Earth's magnetopause has been shown to be a computationally cheap, yet powerful approach to predicting where processes operate on the boundary under given conditions. Here I introduce recent applications of this modeling approach to the magnetopauses of the outermost giant planets (Saturn, Uranus, and Neptune), before presenting a new Jupiter model that treats both magnetic reconnection and growth of the Kelvin-Helmholtz instability. I discuss the sensitivity of the model predictions to variations in both internal and external conditions. This Jovian magnetopause model is designed to support the interpretation of Juno observations of the mysterious polar aurora, with the aim of determining whether these emissions are driven by the interaction with the solar wind.

  3. Making Risk Models Operational for Situational Awareness and Decision Support

    SciTech Connect

    Paulson, Patrick R.; Coles, Garill A.; Shoemaker, Steven V.

    2012-06-12

    Modernization of nuclear power operations control systems, in particular the move to digital control systems, creates an opportunity to modernize existing legacy infrastructure and extend plant life. We describe here decision support tools that allow the assessment of different facets of risk and support the optimization of available resources to reduce risk as plants are upgraded and maintained. This methodology could become an integrated part of the design review process and a part of the operations management systems. The methodology can be applied to the design of new reactors such as small nuclear reactors (SMR), and be helpful in assessing the risks of different configurations of the reactors. Our tool provides a low cost evaluation of alternative configurations and provides an expanded safety analysis by considering scenarios while early in the implementation cycle where cost impacts can be minimized. The effects of failures can be modeled and thoroughly vetted to understand their potential impact on risk. The process and tools presented here allow for an integrated assessment of risk by supporting traditional defense in depth approaches while taking into consideration the insertion of new digital instrument and control systems.

  4. Combining decision support and image processing: a PROforma model.

    PubMed

    Sordo, M; Fox, J; Blum, C; Taylor, P; Lee, R; Alberdi, E

    2001-01-01

    This paper addresses two important problems in medical image interpretation:(1) integration of numeric and symbolic information, (2) access to external sources of medical knowledge. We have developed a prototype in which image processing algorithms are combined with symbolic representations for reasoning, decision making and task management in an integrated, platform-independent system for the differential diagnosis of abnormalities in mammograms. The prototype is based on PROforma, a generic technology for building decision support systems based on clinical guidelines. The PROforma language defines a set of tasks, one of which, the enquiry, is used as means of interaction with the outside world. However, the current enquiry model has proved to be too limited for our purposes. In this paper we outline a more general model, which can be used as an interface between symbolic functions and image or other signal data.

  5. Mass balances for a biological life support system simulation model

    NASA Technical Reports Server (NTRS)

    Volk, Tyler; Rummel, John D.

    1987-01-01

    Design decisions to aid the development of future space based biological life support systems (BLSS) can be made with simulation models. The biochemistry stoichiometry was developed for: (1) protein, carbohydrate, fat, fiber, and lignin production in the edible and inedible parts of plants; (2) food consumption and production of organic solids in urine, feces, and wash water by the humans; and (3) operation of the waste processor. Flux values for all components are derived for a steady state system with wheat as the sole food source. The large scale dynamics of a materially closed (BLSS) computer model is described in a companion paper. An extension of this methodology can explore multifood systems and more complex biochemical dynamics while maintaining whole system closure as a focus.

  6. A community college model to support nursing workforce diversity.

    PubMed

    Colville, Janet; Cottom, Sherry; Robinette, Teresa; Wald, Holly; Waters, Tomi

    2015-02-01

    Community College of Allegheny County (CCAC), Allegheny Campus, is situated on the North Side of Pittsburgh. The neighborhood is 60% African American. At the time of the Health Resources and Services Administration (HRSA) application, approximately one third of the students admitted to the program were African American, less than one third of whom successfully completed it. With the aid of HRSA funding, CCAC developed a model that significantly improved the success rate of disadvantaged students. Through the formation of a viable cohort, the nursing faculty nurtured success among the most at-risk students. The cohort was supported by a social worker, case managers who were nursing faculty, and tutors. Students formed study groups, actively participated in community activities, and developed leadership skills through participation in the Student Nurse Association of Pennsylvania. This article provides the rationale for the Registered Nurse (RN) Achievement Model, describes the components of RN Achievement, and discusses the outcomes of the initiative.

  7. Evaluation of an Individual Placement and Support model (IPS) program.

    PubMed

    Lucca, Anna M; Henry, Alexis D; Banks, Steven; Simon, Lorna; Page, Stephanie

    2004-01-01

    While randomized clinical trials (RCTs) have helped to establish Individual Placement and Support (IPS) programs as an evidence-based practice, it is important to evaluate whether "real world" IPS programs can be implemented with fidelity and achieve outcomes comparable to programs evaluated in RCTs. The current evaluation examined retrospectively employment outcomes for go participants from an IPS-model Services for Employment and Education (SEE) program in Massachusetts over a 4.5-year period. Evaluators accessed demographic, functioning, and employment data from three sources--SEE program records/database, clinical records, and the Massachusetts Department of Mental Health Client Tracking system. Results indicate that the SEE program maintained high IPS fidelity and achieved employment outcomes comparable or superior to other SE and IPS model programs described in the literature.

  8. Mathematical modelling to support traceable dynamic calibration of pressure sensors

    NASA Astrophysics Data System (ADS)

    Matthews, C.; Pennecchi, F.; Eichstädt, S.; Malengo, A.; Esward, T.; Smith, I.; Elster, C.; Knott, A.; Arrhén, F.; Lakka, A.

    2014-06-01

    This paper focuses on the mathematical modelling required to support the development of new primary standard systems for traceable calibration of dynamic pressure sensors. We address two fundamentally different approaches to realizing primary standards, specifically the shock tube method and the drop-weight method. Focusing on the shock tube method, the paper presents first results of system identification and discusses future experimental work that is required to improve the mathematical and statistical models. We use simulations to identify differences between the shock tube and drop-weight methods, to investigate sources of uncertainty in the system identification process and to assist experimentalists in designing the required measuring systems. We demonstrate the identification method on experimental results and draw conclusions.

  9. Advanced development of atmospheric models. [SEASAT Program support

    NASA Technical Reports Server (NTRS)

    Kesel, P. G.; Langland, R. A.; Stephens, P. L.; Welleck, R. E.; Wolff, P. M.

    1979-01-01

    A set of atmospheric analysis and prediction models was developed in support of the SEASAT Program existing objective analysis models which utilize a 125x125 polar stereographic grid of the Northern Hemisphere, which were modified in order to incorporate and assess the impact of (real or simulated) satellite data in the analysis of a two-day meteorological scenario in January 1979. Program/procedural changes included: (1) a provision to utilize winds in the sea level pressure and multi-level height analyses (1000-100 MBS); (2) The capability to perform a pre-analysis at two control levels (1000 MBS and 250 MBS); (3) a greater degree of wind- and mass-field coupling, especially at these controls levels; (4) an improved facility to bogus the analyses based on results of the preanalysis; and (5) a provision to utilize (SIRS) satellite thickness values and cloud motion vectors in the multi-level height analysis.

  10. Flow caused by the stalk contraction of Vorticella

    NASA Astrophysics Data System (ADS)

    Ryu, Sangjin; Chung, Eun-Gul; Admiraal, David

    2016-11-01

    Vorticella is a stalked protozoan, and its ultrafast stalk contraction moves the spherically-shrunken cell body (zooid) and thus causes surrounding water to flow. Because the fluid dynamics of this water flow is important for understanding the motility of Vorticella, we investigated the flow based on various fluid dynamics approaches. To find why Vorticella contracts its stalk, we propose a hypothesis that the protist utilizes the contraction-induced water flow to augment transport of food particles. This hypothesis was investigated using a computational fluid dynamics (CFD) model, which was validated with an experimental scale model of Vorticella. The CFD model enabled calculating the motion of particles around Vorticella and thus quantifying the transport effect of the stalk contraction. Also, we have developed a hydrodynamic drag model for easier estimation of Vorticella's contractility without using the CFD model. Because the contractile force of the stalk equals the drag on the moving zooid, the model enabled evaluating the contractile force and energetics of Vorticella based on its contraction speed. Analyses using the drag model show that the stalk contractility of Vorticella depends on the stalk length. This study was supported by UNL Layman Seed Grant and Nebraska EPSCoR First Award Grant.

  11. Concepts to Support HRP Integration Using Publications and Modeling

    NASA Technical Reports Server (NTRS)

    Mindock, J.; Lumpkins, S.; Shelhamer, M.

    2014-01-01

    Initial efforts are underway to enhance the Human Research Program (HRP)'s identification and support of potential cross-disciplinary scientific collaborations. To increase the emphasis on integration in HRP's science portfolio management, concepts are being explored through the development of a set of tools. These tools are intended to enable modeling, analysis, and visualization of the state of the human system in the spaceflight environment; HRP's current understanding of that state with an indication of uncertainties; and how that state changes due to HRP programmatic progress and design reference mission definitions. In this talk, we will discuss proof-of-concept work performed using a subset of publications captured in the HRP publications database. The publications were tagged in the database with words representing factors influencing health and performance in spaceflight, as well as with words representing the risks HRP research is reducing. Analysis was performed on the publication tag data to identify relationships between factors and between risks. Network representations were then created as one type of visualization of these relationships. This enables future analyses of the structure of the networks based on results from network theory. Such analyses can provide insights into HRP's current human system knowledge state as informed by the publication data. The network structure analyses can also elucidate potential improvements by identifying network connections to establish or strengthen for maximized information flow. The relationships identified in the publication data were subsequently used as inputs to a model captured in the Systems Modeling Language (SysML), which functions as a repository for relationship information to be gleaned from multiple sources. Example network visualization outputs from a simple SysML model were then also created to compare to the visualizations based on the publication data only. We will also discuss ideas for

  12. Advancing Cyberinfrastructure to support high resolution water resources modeling

    NASA Astrophysics Data System (ADS)

    Tarboton, D. G.; Ogden, F. L.; Jones, N.; Horsburgh, J. S.

    2012-12-01

    Addressing the problem of how the availability and quality of water resources at large scales are sensitive to climate variability, watershed alterations and management activities requires computational resources that combine data from multiple sources and support integrated modeling. Related cyberinfrastructure challenges include: 1) how can we best structure data and computer models to address this scientific problem through the use of high-performance and data-intensive computing, and 2) how can we do this in a way that discipline scientists without extensive computational and algorithmic knowledge and experience can take advantage of advances in cyberinfrastructure? This presentation will describe a new system called CI-WATER that is being developed to address these challenges and advance high resolution water resources modeling in the Western U.S. We are building on existing tools that enable collaboration to develop model and data interfaces that link integrated system models running within an HPC environment to multiple data sources. Our goal is to enhance the use of computational simulation and data-intensive modeling to better understand water resources. Addressing water resource problems in the Western U.S. requires simulation of natural and engineered systems, as well as representation of legal (water rights) and institutional constraints alongside the representation of physical processes. We are establishing data services to represent the engineered infrastructure and legal and institutional systems in a way that they can be used with high resolution multi-physics watershed modeling at high spatial resolution. These services will enable incorporation of location-specific information on water management infrastructure and systems into the assessment of regional water availability in the face of growing demands, uncertain future meteorological forcings, and existing prior-appropriations water rights. This presentation will discuss the informatics

  13. Modelling Vague Knowledge for Decision Support in Planning Archaeological Prospections

    NASA Astrophysics Data System (ADS)

    Boos, S.; Hornung, S.; Müller, H.

    2012-07-01

    Most archaeological predictive models lack significance because fuzziness of data and uncertainty in knowledge about human behaviour and natural processes are hardly ever considered. One possibility to cope with such uncertainties is utilization of probability based approaches like Bayes Theorem or Dempster-Shafer-Theory. We analyzed an area of 50 km2 in Rhineland Palatinate (Germany) near a Celtic oppidum by use of Dempster-Shafer's theory of evidence for predicting spatial probability distribution of archaeological sites. This technique incorporates uncertainty by assigning various weights of evidence to defined variables, in that way estimating the probability for supporting a specific hypothesis (in our case the hypothesis presence or absence of a site). Selection of variables for our model relied both on assumptions about settlement patterns and on statistically tested relationships between known archaeological sites and environmental factors. The modelling process was conducted in a Geographic Information System (GIS) by generating raster-based likelihood surfaces. The corresponding likelihood surfaces were aggregated to a final weight of evidence surface, which resulted in a likelihood value for every single cell of being a site or a non-site. Finally the result was tested against a database of known archaeological sites for evaluating the gain of the model. For the purpose of enhancing the gain of our model and sharpening our criteria we used a two-step approach to improve the modelling of former settlement strategies in our study area. Applying the developed model finally yielded a 100 percent success rate of known archaeological sites located in predicted high potential areas.

  14. Ecological footprint model using the support vector machine technique.

    PubMed

    Ma, Haibo; Chang, Wenjuan; Cui, Guangbai

    2012-01-01

    The per capita ecological footprint (EF) is one of the most widely recognized measures of environmental sustainability. It aims to quantify the Earth's biological resources required to support human activity. In this paper, we summarize relevant previous literature, and present five factors that influence per capita EF. These factors are: National gross domestic product (GDP), urbanization (independent of economic development), distribution of income (measured by the Gini coefficient), export dependence (measured by the percentage of exports to total GDP), and service intensity (measured by the percentage of service to total GDP). A new ecological footprint model based on a support vector machine (SVM), which is a machine-learning method based on the structural risk minimization principle from statistical learning theory was conducted to calculate the per capita EF of 24 nations using data from 123 nations. The calculation accuracy was measured by average absolute error and average relative error. They were 0.004883 and 0.351078% respectively. Our results demonstrate that the EF model based on SVM has good calculation performance.

  15. Ecological Footprint Model Using the Support Vector Machine Technique

    PubMed Central

    Ma, Haibo; Chang, Wenjuan; Cui, Guangbai

    2012-01-01

    The per capita ecological footprint (EF) is one of the most widely recognized measures of environmental sustainability. It aims to quantify the Earth's biological resources required to support human activity. In this paper, we summarize relevant previous literature, and present five factors that influence per capita EF. These factors are: National gross domestic product (GDP), urbanization (independent of economic development), distribution of income (measured by the Gini coefficient), export dependence (measured by the percentage of exports to total GDP), and service intensity (measured by the percentage of service to total GDP). A new ecological footprint model based on a support vector machine (SVM), which is a machine-learning method based on the structural risk minimization principle from statistical learning theory was conducted to calculate the per capita EF of 24 nations using data from 123 nations. The calculation accuracy was measured by average absolute error and average relative error. They were 0.004883 and 0.351078% respectively. Our results demonstrate that the EF model based on SVM has good calculation performance. PMID:22291949

  16. Essays on incomplete contracts in regulatory activities

    NASA Astrophysics Data System (ADS)

    Saavedra, Eduardo Humberto

    This dissertation consists of three essays. The first essay, The Hold-Up Problem in Public Infrastructure Franchising, characterizes the equilibria of the investment decisions in public infrastructure franchising under incomplete contracting and ex-post renegotiation. The parties (government and a firm) are unable to credibly commit to the contracted investment plan, so that a second step investment is renegotiated by the parties at the revision stage. As expected, the possibility of renegotiation affects initial non-verifiable investments. The main conclusion of this essay is that not only underinvestment but also overinvestment in infrastructure may arise in equilibrium, compared to the complete contracting case. The second essay, Alternative Institutional Arrangements in Network Utilities: An Incomplete Contracting Approach, presents a theoretical assessment of the efficiency implications of privatizing natural monopolies which are vertically related to potential competitive firms. Based on the incomplete contracts and asymmetric information paradigm. I develop a model that analyzes the relative advantages of different institutional arrangements---alternative ownership and market structures in the industry--- in terms of their allocative and productive efficiencies. The main policy conclusion of this essay is that both ownership and the existence of conglomerates in network industries matter. Among other conclusions, this essay provides an economic rationale for a mixed economy in which the network is public and vertical separation of the industry when the natural monopoly is under private ownership. The last essay, Opportunistic Behavior and Legal Disputes in the Chilean Electricity Sector, analyzes post-contractual disputes in this newly privatized industry. It discusses the presumption that opportunistic behavior and disputes arise due to inadequate market design, ambiguous regulation, and institutional weaknesses. This chapter also assesses the presumption

  17. Supporting user-defined granularities in a spatiotemporal conceptual model

    USGS Publications Warehouse

    Khatri, V.; Ram, S.; Snodgrass, R.T.; O'Brien, G. M.

    2002-01-01

    Granularities are integral to spatial and temporal data. A large number of applications require storage of facts along with their temporal and spatial context, which needs to be expressed in terms of appropriate granularities. For many real-world applications, a single granularity in the database is insufficient. In order to support any type of spatial or temporal reasoning, the semantics related to granularities needs to be embedded in the database. Specifying granularities related to facts is an important part of conceptual database design because under-specifying the granularity can restrict an application, affect the relative ordering of events and impact the topological relationships. Closely related to granularities is indeterminacy, i.e., an occurrence time or location associated with a fact that is not known exactly. In this paper, we present an ontology for spatial granularities that is a natural analog of temporal granularities. We propose an upward-compatible, annotation-based spatiotemporal conceptual model that can comprehensively capture the semantics related to spatial and temporal granularities, and indeterminacy without requiring new spatiotemporal constructs. We specify the formal semantics of this spatiotemporal conceptual model via translation to a conventional conceptual model. To underscore the practical focus of our approach, we describe an on-going case study. We apply our approach to a hydrogeologic application at the United States Geologic Survey and demonstrate that our proposed granularity-based spatiotemporal conceptual model is straightforward to use and is comprehensive.

  18. Agricultural Model for the Nile Basin Decision Support System

    NASA Astrophysics Data System (ADS)

    van der Bolt, Frank; Seid, Abdulkarim

    2014-05-01

    To analyze options for increasing food supply in the Nile basin the Nile Agricultural Model (AM) was developed. The AM includes state-of-the-art descriptions of biophysical, hydrological and economic processes and realizes a coherent and consistent integration of hydrology, agronomy and economics. The AM covers both the agro-ecological domain (water, crop productivity) and the economic domain (food supply, demand, and trade) and allows to evaluate the macro-economic and hydrological impacts of scenarios for agricultural development. Starting with the hydrological information from the NileBasin-DSS the AM calculates the available water for agriculture, the crop production and irrigation requirements with the FAO-model AquaCrop. With the global commodity trade model MAGNET scenarios for land development and conversion are evaluated. The AM predicts consequences for trade, food security and development based on soil and water availability, crop allocation, food demand and food policy. The model will be used as a decision support tool to contribute to more productive and sustainable agriculture in individual Nile countries and the whole region.

  19. Modeling Global Urbanization Supported by Nighttime Light Remote Sensing

    NASA Astrophysics Data System (ADS)

    Zhou, Y.

    2015-12-01

    Urbanization, a major driver of global change, profoundly impacts our physical and social world, for example, altering carbon cycling and climate. Understanding these consequences for better scientific insights and effective decision-making unarguably requires accurate information on urban extent and its spatial distributions. In this study, we developed a cluster-based method to estimate the optimal thresholds and map urban extents from the nighttime light remote sensing data, extended this method to the global domain by developing a computational method (parameterization) to estimate the key parameters in the cluster-based method, and built a consistent 20-year global urban map series to evaluate the time-reactive nature of global urbanization (e.g. 2000 in Fig. 1). Supported by urban maps derived from nightlights remote sensing data and socio-economic drivers, we developed an integrated modeling framework to project future urban expansion by integrating a top-down macro-scale statistical model with a bottom-up urban growth model. With the models calibrated and validated using historical data, we explored urban growth at the grid level (1-km) over the next two decades under a number of socio-economic scenarios. The derived spatiotemporal information of historical and potential future urbanization will be of great value with practical implications for developing adaptation and risk management measures for urban infrastructure, transportation, energy, and water systems when considered together with other factors such as climate variability and change, and high impact weather events.

  20. Model catalytic oxidation studies using supported monometallic and heterobimetallic oxides

    SciTech Connect

    Ekerdt, J.G.

    1992-02-03

    This research program is directed toward a more fundamental understanding of the effects of catalyst composition and structure on the catalytic properties of metal oxides. Metal oxide catalysts play an important role in many reactions bearing on the chemical aspects of energy processes. Metal oxides are the catalysts for water-gas shift reactions, methanol and higher alcohol synthesis, isosynthesis, selective catalytic reduction of nitric oxides, and oxidation of hydrocarbons. A key limitation to developing insight into how oxides function in catalytic reactions is in not having precise information of the surface composition under reaction conditions. To address this problem we have prepared oxide systems that can be used to study cation-cation effects and the role of bridging (-O-) and/or terminal (=O) surface oxygen anion ligands in a systematic fashion. Since many oxide catalyst systems involve mixtures of oxides, we selected a model system that would permit us to examine the role of each cation separately and in pairwise combinations. Organometallic molybdenum and tungsten complexes were proposed for use, to prepare model systems consisting of isolated monomeric cations, isolated monometallic dimers and isolated bimetallic dimers supported on silica and alumina. The monometallic and bimetallic dimers were to be used as models of more complex mixed- oxide catalysts. Our current program was to develop the systems and use them in model oxidation reactions.

  1. Modeling decision support rule interactions in a clinical setting.

    PubMed

    Sordo, Margarita; Rocha, Beatriz H; Morales, Alfredo A; Maviglia, Saverio M; Oglio, Elisa Dell'Oglio; Fairbanks, Amanda; Aroy, Teal; Dubois, David; Bouyer-Ferullo, Sharon; Rocha, Roberto A

    2013-01-01

    Traditionally, rule interactions are handled at implementation time through rule task properties that control the order in which rules are executed. By doing so, knowledge about the behavior and interactions of decision rules is not captured at modeling time. We argue that this is important knowledge that should be integrated in the modeling phase. In this project, we build upon current work on a conceptual schema to represent clinical knowledge for decision support in the form of if then rules. This schema currently captures provenance of the clinical content, context where such content is actionable (i.e. constraints) and the logic of the rule itself. For this project, we borrowed concepts from both the Semantic Web (i.e., Ontologies) and Complex Adaptive Systems (CAS), to explore a conceptual approach for modeling rule interactions in an enterprise-wide clinical setting. We expect that a more comprehensive modeling will facilitate knowledge authoring, editing and update; foster consistency in rules implementation and maintenance; and develop authoritative knowledge repositories to promote quality, safety and efficacy of healthcare.

  2. Species-specific ecological niche modelling predicts different range contractions for Lutzomyia intermedia and a related vector of Leishmania braziliensis following climate change in South America.

    PubMed

    McIntyre, Shannon; Rangel, Elizabeth F; Ready, Paul D; Carvalho, Bruno M

    2017-03-24

    Before 1996 the phlebotomine sand fly Lutzomyia neivai was usually treated as a synonym of the morphologically similar Lutzomyia intermedia, which has long been considered a vector of Leishmania braziliensis, the causative agent of much cutaneous leishmaniasis in South America. This report investigates the likely range changes of both sand fly species in response to a stabilisation climate change scenario (RCP4.5) and a high greenhouse gas emissions one (RCP8.5). Ecological niche modelling was used to identify areas of South America with climates currently suitable for each species, and then the future distributions of these climates were predicted based on climate change scenarios. Compared with the previous ecological niche model of L. intermedia (sensu lato) produced using the GARP algorithm in 2003, the current investigation modelled the two species separately, making use of verified presence records and additional records after 2001. Also, the new ensemble approach employed ecological niche modelling algorithms (including Maximum Entropy, Random Forests and Support Vector Machines) that have been widely adopted since 2003 and perform better than GARP, as well as using a more recent climate change model (HadGEM2) considered to have better performance at higher resolution than the earlier one (HadCM2). Lutzomyia intermedia was shown to be the more tropical of the two species, with its climatic niche defined by higher annual mean temperatures and lower temperature seasonality, in contrast to the more subtropical L. neivai. These different latitudinal ranges explain the two species' predicted responses to climate change by 2050, with L. intermedia mostly contracting its range (except perhaps in northeast Brazil) and L. neivai mostly shifting its range southwards in Brazil and Argentina. This contradicts the findings of the 2003 report, which predicted more range expansion. The different findings can be explained by the improved data sets and modelling methods. Our

  3. Increased angiotensin II contraction of the uterine artery at early gestation in a transgenic model of hypertensive pregnancy is reduced by inhibition of endocannabinoid hydrolysis.

    PubMed

    Pulgar, Victor M; Yamaleyeva, Liliya M; Varagic, Jasmina; McGee, Carolynne M; Bader, Michael; Dechend, Ralf; Howlett, Allyn C; Brosnihan, K Bridget

    2014-09-01

    Increased vascular sensitivity to angiotensin II (Ang II) is a marker of a hypertensive human pregnancy. Recent evidence of interactions between the renin-angiotensin system and the endocannabinoid system suggests that anandamide and 2-arachidonoylglycerol may modulate Ang II contraction. We hypothesized that these interactions may contribute to the enhanced vascular responses in hypertensive pregnancy. We studied Ang II contraction in isolated uterine artery (UA) at early gestation in a rat model that mimics many features of preeclampsia, the transgenic human angiotensinogen×human renin (TgA), and control Sprague-Dawley rats. We determined the role of the cannabinoid receptor 1 by blockade with SR171416A, and the contribution of anandamide and 2-arachidonoylglycerol degradation to Ang II contraction by inhibiting their hydrolyzing enzyme fatty acid amide hydrolase (with URB597) or monoacylglycerol lipase (with JZL184), respectively. TgA UA showed increased maximal contraction and sensitivity to Ang II that was inhibited by indomethacin. Fatty acid amide hydrolase blockade decreased Ang IIMAX in Sprague-Dawley UA, and decreased both Ang IIMAX and sensitivity in TgA UA. Monoacylglycerol lipase blockade had no effect on Sprague-Dawley UA and decreased Ang IIMAX and sensitivity in TgA UA. Blockade of the cannabinoid receptor 1 in TgA UA had no effect. Immunolocalization of fatty acid amide hydrolase and monoacylglycerol lipase showed a similar pattern between groups; fatty acid amide hydrolase predominantly localized in endothelium and monoacylglycerol lipase in smooth muscle cells. We demonstrated an increased Ang II contraction in TgA UA before initiation of the hypertensive phenotype. Anandamide and 2-arachidonoylglycerol reduced Ang II contraction in a cannabinoid receptor 1-independent manner. These renin-angiotensin system-endocannabinoid system interactions may contribute to the enhanced vascular reactivity in early stages of hypertensive pregnancy.

  4. Geobrowser based simulation models for land degradation policy support

    NASA Astrophysics Data System (ADS)

    Mulligan, M.

    2009-04-01

    Nature is complex and is complicated further by the gaps in our knowledge of it. Whereas scientists often quote lack of data and the need for more research from our seat on the fence, those making policy and attempting to manage nature and our interactions with it need to make decisions on what to do and how to do it. Increasingly reductionist science has led to deeper understanding of isolated process but only recently have advances in systems analysis, environmental modelling and computing enabled the construction of integrated models from these slices of science. Such integrated (assessment) models (IAMs) attempt to simulate landscapes and the biophysical and socio-economic processes occurring within them over space and time. IAMs provide a testbed in which policy can be tested in silico before being implemented in vivo. They are often used to assess the potential implications of implementing particular policy options in the face of background scenarios of change such as population growth and climate variability or change. In this paper I will show an example of an IAM for fine scale land degradation processes in the Mediterranean. The model, which incorporates many of the hydrological, plant growth and soil degradation processes acting in these environments, was developed as part of the EC funded DESURVEY project. It is fundamentally built on data, process knowledge and training developed within the MEDALUS series of projects, led by John Thornes. The DESURVEY fine scale model is implemented as a web-service and integrated with geobrowsers like Google Earth and Google Maps whilst drawing on terabytes of environmental data hosted at www.kcl.ac.uk/geodata and grid based dynamic models for surface and subsurface processes. This IAM is aimed at quantifying and visualising interactively the interaction between climate, land cover and land degradation, for policy support.

  5. Urban modeling over Houston in support of SIMMER

    NASA Astrophysics Data System (ADS)

    Barlage, M. J.; Monaghan, A. J.; Feddema, J. J.; Oleson, K. W.; Brunsell, N. A.; Wilhelmi, O.

    2011-12-01

    Extreme heat is a leading cause of weather-related human mortality in the United States. As global warming patterns continue, researchers anticipate increases in the severity, frequency and duration of extreme heat events, especially in the southern and western U.S. Many cities in these regions may have amplified vulnerability due to their rapidly evolving socioeconomic fabric (for example, growing elderly populations). This raises a series of questions about the increased health risks of urban residents to extreme heat, and about effective means of mitigation and adaptation in present and future climates. We will introduce a NASA-funded project aimed at addressing these questions via the System for Integrated Modeling of Metropolitan Extreme Heat Risk (SIMMER). Through SIMMER, we hope to advance methodology for assessing current and future urban vulnerabilities from the heat waves through the refinement and integration of physical and social science models, and to build local capacity for heat hazard mitigation and climate change adaptation in the public health sector. We will also present results from a series of sensitivity studies over Houston and surrounding area employing a recently-implemented multi-layer urban canopy model (UCM) within the Noah Land Surface Model. The UCM has multiple layers in the atmosphere to explicitly resolve the effects of buildings, and has an indoor-outdoor exchange model that directly interacts with the atmospheric boundary layer. The goal of this work, which supports the physical science component of SIMMER, is to characterize the ill-defined and uncertain parameter space, including building characteristics and spatial organization, in the new multi-layer UCM for Houston, and to assess whether and how this parameter space is sensitive to the choice of urban morphology datasets. Results focus on the seasonal and inter-annual range of both the modeled urban heat island effect and the magnitude of surface energy components and

  6. Modeling age-related changes in muscle-tendon dynamics during cyclical contractions in the rat gastrocnemius

    PubMed Central

    Holt, Natalie C.; Sawicki, Gregory S.; Azizi, Emanuel

    2016-01-01

    Efficient muscle-tendon performance during cyclical tasks is dependent on both active and passive mechanical tissue properties. Here we examine whether age-related changes in the properties of muscle-tendon units (MTUs) compromise their ability to do work and utilize elastic energy storage. We empirically quantified passive and active properties of the medial gastrocnemius muscle and material properties of the Achilles tendon in young (∼6 mo) and old (∼32 mo) rats. We then used these properties in computer simulations of a Hill-type muscle model operating in series with a Hookean spring. The modeled MTU was driven through sinusoidal length changes and activated at a phase that optimized muscle-tendon tuning to assess the relative contributions of active and passive elements to the force and work in each cycle. In physiologically realistic simulations where young and old MTUs started at similar passive forces and developed similar active forces, the capacity of old MTUs to store elastic energy and produce positive work was compromised. These results suggest that the observed increase in the metabolic cost of locomotion with aging may be in part due to the recruitment of additional muscles to compensate for the reduced work at the primary MTU. Furthermore, the age-related increases in passive stiffness coupled with a reduced active force capacity in the muscle can lead to shifts in the force-length and force-velocity operating range that may significantly impact mechanical and metabolic performance. Our study emphasizes the importance of the interplay between muscle and tendon mechanical properties in shaping MTU performance during cyclical contractions. PMID:27493196

  7. Modelling evolution on design-by-contract predicts an origin of Life through an abiotic double-stranded RNA world

    PubMed Central

    de Roos, Albert DG

    2007-01-01

    Background It is generally believed that life first evolved from single-stranded RNA (ssRNA) that both stored genetic information and catalyzed the reactions required for self-replication. Presentation of the hypothesis By modeling early genome evolution on the engineering paradigm design-by-contract, an alternative scenario is presented in which life started with the appearance of double-stranded RNA (dsRNA) as an informational storage molecule while catalytic single-stranded RNA was derived from this dsRNA template later in evolution. Testing the hypothesis It was investigated whether this scenario could be implemented mechanistically by starting with abiotic processes. Double-stranded RNA could be formed abiotically by hybridization of oligoribonucleotides that are subsequently non-enzymatically ligated into a double-stranded chain. Thermal cycling driven by the diurnal temperature cycles could then replicate this dsRNA when strands of dsRNA separate and later rehybridize and ligate to reform dsRNA. A temperature-dependent partial replication of specific regions of dsRNA could produce the first template-based generation of catalytic ssRNA, similar to the developmental gene transcription process. Replacement of these abiotic processes by enzymatic processes would guarantee functional continuity. Further transition from a dsRNA to a dsDNA world could be based on minor mutations in template and substrate recognition sites of an RNA polymerase and would leave all existing processes intact. Implications of the hypothesis Modeling evolution on a design pattern, the 'dsRNA first' hypothesis can provide an alternative mechanistic evolutionary scenario for the origin of our genome that preserves functional continuity. Reviewers This article was reviewed by Anthony Poole, Eugene Koonin and Eugene Shakhnovich PMID:17466073

  8. Modeling age-related changes in muscle-tendon dynamics during cyclical contractions in the rat gastrocnemius.

    PubMed

    Danos, Nicole; Holt, Natalie C; Sawicki, Gregory S; Azizi, Emanuel

    2016-10-01

    Efficient muscle-tendon performance during cyclical tasks is dependent on both active and passive mechanical tissue properties. Here we examine whether age-related changes in the properties of muscle-tendon units (MTUs) compromise their ability to do work and utilize elastic energy storage. We empirically quantified passive and active properties of the medial gastrocnemius muscle and material properties of the Achilles tendon in young (∼6 mo) and old (∼32 mo) rats. We then used these properties in computer simulations of a Hill-type muscle model operating in series with a Hookean spring. The modeled MTU was driven through sinusoidal length changes and activated at a phase that optimized muscle-tendon tuning to assess the relative contributions of active and passive elements to the force and work in each cycle. In physiologically realistic simulations where young and old MTUs started at similar passive forces and developed similar active forces, the capacity of old MTUs to store elastic energy and produce positive work was compromised. These results suggest that the observed increase in the metabolic cost of locomotion with aging may be in part due to the recruitment of additional muscles to compensate for the reduced work at the primary MTU. Furthermore, the age-related increases in passive stiffness coupled with a reduced active force capacity in the muscle can lead to shifts in the force-length and force-velocity operating range that may significantly impact mechanical and metabolic performance. Our study emphasizes the importance of the interplay between muscle and tendon mechanical properties in shaping MTU performance during cyclical contractions. Copyright © 2016 the American Physiological Society.

  9. Contracts for field projects and supporting research on enhanced oil recovery, October--December 1992. Progress review No. 73, quarter ending December 31, 1992

    SciTech Connect

    Not Available

    1993-12-01

    Accomplishments for this quarter ending December 31, 1992 are presented for the following tasks: chemical flooding--supporting research; gas displacement--supporting research; thermal recovery--supporting research; geoscience technology; resource assessment technology; microbial technology; reservoir classes; and novel technology.

  10. Contracts for field projects and supporting research on enhanced oil recovery, July--September 1992. Progress review No. 72, quarter ending September 30, 1992

    SciTech Connect

    Not Available

    1993-09-01

    Accomplishments for the past quarter are presented for the following tasks: Chemical flooding--supporting research; gas displacement--supporting research; thermal recovery--supporting research; geoscience technology; resource assessment technology; microbial technology; and novel technology. A list of available publication is also provided.

  11. Russian Contract Procurement Document

    SciTech Connect

    Tobin, J G

    2010-03-29

    This contract supports the enhancement of physical protection or nuclear material control and accounting systems at institutes or enterprises of the newly independent states under the material protection control and accounting (MPC&A) program. The contract is entered into pursuant to the MPC&A Program, a gratuitous technical assistance program, in accordance with the bilateral Agreements between the Russian Federation and the United States of America concerning the Safe and Secure Transportation, Storage and Destruction of Weapons and the Prevention of Weapons Proliferation of June 1992, as extended and amended by Protocol signed of June 1999, Agreement between the Government of the Russian Federation regarding Cooperation in the Area of Nuclear Materials Physical Protection, Control and Accounting of October 1999 and the Russian Federation law of May 1999 on the taxation exemption of gratuitous technical assistance with Russian Federation under registration No.DOE001000.

  12. Scour around Support Structures of Scaled Model Marine Hydrokinetic Devices

    NASA Astrophysics Data System (ADS)

    Volpe, M. A.; Beninati, M. L.; Krane, M.; Fontaine, A.

    2013-12-01

    Experiments are presented to explore scour due to flows around support structures of marine hydrokinetic (MHK) devices. Three related studies were performed to understand how submergence, scour condition, and the presence of an MHK device impact scour around the support structure (cylinder). The first study focuses on clear-water scour conditions for a cylinder of varying submergence: surface-piercing and fully submerged. The second study centers on three separate scour conditions (clear-water, transitional and live-bed) around the fully submerged cylinder. Lastly, the third study emphasizes the impact of an MHK turbine on scour around the support structure, in live-bed conditions. Small-scale laboratory testing of model devices can be used to help predict the behavior of MHK devices at full-scale. Extensive studies have been performed on single cylinders, modeling bridge piers, though few have focused on fully submerged structures. Many of the devices being used to harness marine hydrokinetic energy are fully submerged in the flow. Additionally, scour hole dimensions and scour rates have not been addressed. Thus, these three studies address the effect of structure blockage/drag, and the ambient scour conditions on scour around the support structure. The experiments were performed in the small-scale testing platform in the hydraulic flume facility (9.8 m long, 1.2 m wide and 0.4 m deep) at Bucknell University. The support structure diameter (D = 2.54 cm) was held constant for all tests. The submerged cylinder (l/D = 5) and sediment size (d50 = 790 microns) were held constant for all three studies. The MHK device (Dturbine = 10.2 cm) is a two-bladed horizontal axis turbine and the rotating shaft is friction-loaded using a metal brush motor. For each study, bed form topology was measured after a three-hour time interval using a traversing two-dimensional bed profiler. During the experiments, scour hole depth measurements at the front face of the support structure

  13. Early diagnosis model for meningitis supports public health decision making.

    PubMed

    Close, Rebecca M; Ejidokun, Oluwatoyin O; Verlander, Neville Q; Fraser, Graham; Meltzer, Margie; Rehman, Yasmin; Muir, Peter; Ninis, Nelly; Stuart, James M

    2011-07-01

    To develop a predictive model for rapid differential diagnosis of meningitis and meningococcal septicaemia to support public health decisions on chemoprophylaxis for contacts. Prospective study of suspected cases of acute meningitis and meningococcal septicaemia admitted to hospitals in the South West, West Midlands and London Regions of England from July 2008 to June 2009. Epidemiological, clinical and laboratory variables on admission were recorded. Logistic regression was used to derive a predictive model. Of the 719 suspect cases reported, 385 confirmed cases were included in analysis. Peripheral blood polymorphonuclear count of >16 × 10(9)/l, serum C-reactive protein of >100 mg/l and haemorrhagic rash were strongly and independently associated with diagnosis of bacterial meningitis and meningococcal septicaemia. Using a simple scoring system, the presence of any one of these factors gave a probability of >95% in predicting the final diagnosis. We have developed a model using laboratory and clinical factors, but not dependent on availability of CSF, for differentiating acute bacterial from viral meningitis within a few hours of admission to hospital. This scoring system is recommended in public health management of suspected cases of meningitis and meningococcal septicaemia to inform decisions on chemoprophylaxis. Copyright © 2011 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  14. Modeling of chemisorption on copper oxide supported on alumina

    NASA Astrophysics Data System (ADS)

    Hao, Y. G.; Cooper, B. R.

    1994-06-01

    Transition metals supported on alumina are widely used as catalysts, and over the last few decades a large amount of experimental work has been done to characterize such systems. While it is generally believed that the catalytic reactions occur on and near the surface, knowledge of the reactions and the adsorption sites on the surface and related energetics is seriously lacking, especially at the atomic structure level. We have used a combination of the film linearized muffin-tin orbital (FLMTO) method and an ab initio molecular quantum cluster method to model the use of the system of CuO/-γ-Al 2O 3 as a regenerable adsorbent of SO 2 (of interest for flue-gas cleanup). The modeling and calculations with the FLMTO method show that the copper atoms are adsorbed at the surface octahedral vacant sites of the alumina. The modeling and calculations with the ab initio cluster method rule out the adsorption of the SO 2 molecule with sulfur-copper bonding and indicate that the SO 2 molecule is adsorbed via oxygen-copper bonding; and accordingly we investigate some pertinent geometrical configurations including "bridge" arrangements providing bonding between the oxygen atoms of the SO 2 molecule and the surface copper or aluminum atoms.

  15. In Vitro Multitissue Interface Model Supports Rapid Vasculogenesis and Mechanistic Study of Vascularization across Tissue Compartments.

    PubMed

    Buno, Kevin P; Chen, Xuemei; Weibel, Justin A; Thiede, Stephanie N; Garimella, Suresh V; Yoder, Mervin C; Voytik-Harbin, Sherry L

    2016-08-31

    A significant challenge facing tissue engineers is the design and development of complex multitissue systems, including vascularized tissue-tissue interfaces. While conventional in vitro models focus on either vasculogenesis (de novo formation of blood vessels) or angiogenesis (vessels sprouting from existing vessels or endothelial monolayers), successful therapeutic vascularization strategies will likely rely on coordinated integration of both processes. To address this challenge, we developed a novel in vitro multitissue interface model in which human endothelial colony forming cell (ECFC)-encapsulated tissue spheres are embedded within a surrounding tissue microenvironment. This highly reproducible approach exploits biphilic surfaces (nanostructured surfaces with distinct superhydrophobic and hydrophilic regions) to (i) support tissue compartments with user-specified matrix composition and physical properties as well as cell type and density and (ii) introduce boundary conditions that prevent the cell-mediated tissue contraction routinely observed with conventional three-dimensional monodispersion cultures. This multitissue interface model was applied to test the hypothesis that independent control of cell-extracellular matrix (ECM) and cell-cell interactions would affect vascularization within the tissue sphere as well as across the tissue-tissue interface. We found that high-cell-density tissue spheres containing 5 × 10(6) ECFCs/mL exhibit rapid and robust vasculogenesis, forming highly interconnected, stable (as indicated by type IV collagen deposition) vessel networks within only 3 days. Addition of adipose-derived stromal cells (ASCs) in the surrounding tissue further enhanced vasculogenesis within the sphere as well as angiogenic vessel elongation across the tissue-tissue boundary, with both effects being dependent on the ASC density. Overall, results show that the ECFC density and ECFC-ASC crosstalk, in terms of paracrine and mechanophysical signaling

  16. Aggregation of Environmental Model Data for Decision Support

    NASA Astrophysics Data System (ADS)

    Alpert, J. C.

    2013-12-01

    model output offering access to probability and calibrating information for real time decision making. The aggregation content server reports over ensemble component and forecast time in addition to the other data dimensions of vertical layer and position for each variable. The unpacking, organization and reading of many binary packed files is accomplished most efficiently on the server while weather element event probability calculations, the thresholds for more accurate decision support, or display remain for the client. Our goal is to reduce uncertainty for variables of interest, e.g, agricultural importance. The weather service operational GFS model ensemble and short range ensemble forecasts can make skillful probability forecasts to alert users if and when their selected weather events will occur. A description of how this framework operates and how it can be implemented using existing NOMADS content services and applications is described.

  17. Information Integration to Support Model-Based Policy Informatics

    PubMed Central

    Barrett, Christopher L.; Eubank, Stephen; Marathe, Achla; Marathe, Madhav V.; Pan, Zhengzheng; Swarup, Samarth

    2011-01-01

    The complexities of social and technological policy domains, such as the economy, the environment, and public health present challenges that require a new approach to modeling and decision making. The information required for effective policy and decision making in these complex domains is massive in scale, fine-grained in resolution, and distributed over many data sources. Thus, one of the key challenges in building systems to support policy informatics is information integration. We describe our approach to this problem, and how we are building a multi-theory, multi-actor, multi-perspective system that supports continual data uptake, state assessment, decision analysis, and action assignment based on large-scale high-performance computing infrastructures. Our simulation-based approach allows rapid course-of-action analysis to bound variances in outcomes of policy interventions, which in turn allows the short time-scale planning required in response to emergencies such as epidemic outbreaks. We present the rationale and design of our methodology and discuss several areas of actual and potential application. PMID:22337756

  18. Simulation modeling of supported lipid membranes - a review.

    PubMed

    Hirtz, Michael; Kumar, Naresh; Chi, Lifeng

    2014-03-01

    Lipid membranes are of great importance for many biological systems and biotechnological applications. One method to gain a profound understanding of the dynamics in lipid membranes and their interaction with other system components is by modeling these systems by computer simulations. Many different approaches have been undertaken in this endeavor that have led to molecular level insights into the underlying mechanisms of several experimental observations and biological processes with an extremely high temporal resolution. As compared to the free-standing lipid bilayers, there are fewer simulation studies addressing the systems of supported lipid membranes. Nevertheless, these have significantly enhanced our understanding of the behavior of lipid layers employed in applications spanning from biosensors to drug delivery and for biological processes such as the breathing cycle of lung surfactants. In this review, we give an account of the state of the art of methods and applications of the simulations of supported lipid bilayers, interfacial membranes at the air/water interface and on solid surfaces.

  19. Progressor: social navigation support through open social student modeling

    NASA Astrophysics Data System (ADS)

    Hsiao, I.-Han; Bakalov, Fedor; Brusilovsky, Peter; König-Ries, Birgitta

    2013-06-01

    The increased volumes of online learning content have produced two problems: how to help students to find the most appropriate resources and how to engage them in using these resources. Personalized and social learning have been suggested as potential ways to address these problems. Our work presented in this paper combines the ideas of personalized and social learning in the context of educational hypermedia. We introduce Progressor, an innovative Web-based tool based on the concepts of social navigation and open student modeling that helps students to find the most relevant resources in a large collection of parameterized self-assessment questions on Java programming. We have evaluated Progressor in a semester-long classroom study, the results of which are presented in this paper. The study confirmed the impact of personalized social navigation support provided by the system in the target context. The interface encouraged students to explore more topics attempting more questions and achieving higher success rates in answering them. A deeper analysis of the social navigation support mechanism revealed that the top students successfully led the way to discovering most relevant resources by creating clear pathways for weaker students.

  20. The picture superiority effect: support for the distinctiveness model.

    PubMed

    Mintzer, M Z; Snodgrass, J G

    1999-01-01

    The form change paradigm was used to explore the basis for the picture superiority effect. Recognition memory for studied pictures and words was tested in their study form or the alternate form. Form change cost was defined as the difference between recognition performance for same and different form items. Based on the results of Experiment 1 and previous studies, it was difficult to determine the relative cost for studied pictures and words due to a reversal of the mirror effect. We hypothesized that the reversed mirror effect results from subjects' basing their recognition decisions on their assumptions about the study form. Experiments 2 and 3 confirmed this hypothesis and generated a method for evaluating the relative cost for pictures and words despite the reversed mirror effect. More cost was observed for pictures than words, supporting the distinctiveness model of the picture superiority effect.