Sample records for existing models fail

  1. 76 FR 10288 - Airworthiness Directives; The Boeing Company Model 767-200, -300, -300F, and -400ER Series Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-24

    ... and corrosion to an area within five inches of the fail-safe strap. Revision 2 of this service.... The existing AD currently requires inspections to detect cracking or corrosion of the fail-safe straps... corrective actions. Since we issued that AD, we have received additional reports of cracks in 51 fail-safe...

  2. 76 FR 38074 - Airworthiness Directives; The Boeing Company Model 747-100, 747-100B, 747-200B, 747-200C, 747...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-29

    ... withstand fail-safe loads. DATES: We must receive comments on this proposed AD by August 15, 2011. ADDRESSES... pressurization and the inability of the airplane fuselage to withstand fail-safe loads. Actions Since Existing AD... withstand fail-safe loads. Compliance (f) You are responsible for having the actions required by this AD...

  3. 76 FR 31453 - Special Conditions: Gulfstream Model GVI Airplane; Single-Occupant Side-Facing Seats

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-01

    .... SID TTI data must be processed as defined in Federal Motor Vehicle Safety Standard (FMVSS) part 571...). Pass/fail injury assessments: TTI and pelvic acceleration. 2. One longitudinal test with the Hybrid II... pelvic acceleration. 3. Vertical (14g) test with modified Hybrid II ATDs using existing pass/fail...

  4. A CONCEPTUAL MODEL FOR ECOSYSTEM - HUMAN HEALTH INTERCONNECTIONS

    EPA Science Inventory

    Much environmental policy fails to consider the relationships that exist among component parts of the natural and social world. The linkages that exist between natural and social systems are intricate and varied and call for new and creative approaches to environmental policy and...

  5. Process Time Refinement for Reusable Launch Vehicle Regeneration Modeling

    DTIC Science & Technology

    2008-03-01

    predicted to fail, or have failed. 3) Augmenting existing space systems with redundant or additional capability to enhance space system performance or...Canopies, External Tanks/Pods/Pylon Ejectors , Armament Bay Doors, Missile Launchers, Wing and Fuselage Center Line Racks, Bomb Bay Release...Systems Test 04583 Thrust Maintenance Operation 04584 Silo Door Operation 04650 Initial Build-up-Recovery Vehicle (RV) 147 04610 Nondestructive

  6. 75 FR 27409 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S-92A Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-17

    ... gearbox (MGB) filter bowl assembly with a two-piece MGB filter bowl assembly and replacing the existing mounting studs. The AD also requires inspecting the MGB lube system filters, the housing, the housing... prompted by tests indicating that an existing MGB filter bowl assembly can fail under certain loading...

  7. Combustion of Nitramine Propellants

    DTIC Science & Technology

    1983-03-01

    through development of a comprehensive analytical model. The ultimate goals are to enable prediction of deflagration rate over a wide pressure range...superior in burn rate prediction , both simple models fail in correlating existing temperature- sensitivity data. (2) In the second part, a...auxiliary condition to enable independent burn rate prediction ; improved melt phase model including decomposition-gas bubbles; model for far-field

  8. A dynamic magnetic tension force as the cause of failed solar eruptions

    DOE Data Explorer

    Myers, Clayton E. [Princeton Univ., NJ (United States). Dept. of Astrophysical Sciences; Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); ] (ORCID:0000000345398406); Yamada, Maasaki [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)] (ORCID:0000000349961649); Ji, Hantao [Princeton Univ., NJ (United States). Dept. of Astrophysical Sciences; Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Laboratory for Space Environment and Physical Sciences, Harbin Institute of Technology, Harbin, Heilongjiang 150001, China] (ORCID:0000000196009963); Yoo, Jongsoo [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)] (ORCID:0000000338811995); Fox, William [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)] (ORCID:000000016289858X); Jara-Almonte, Jonathan [Princeton Univ., NJ (United States). Dept. of Astrophysical Sciences; Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); ] (ORCID:0000000307606198); Savcheva, Antonia [Harvard†“ Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA] (ORCID:000000025598046X); DeLuca, Edward E. [Harvard†“ Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA] (ORCID:0000000174162895)

    2015-12-11

    Coronal mass ejections are solar eruptions driven by a sudden release of magnetic energy stored in the Sun’s corona. In many cases, this magnetic energy is stored in long-lived, arched structures called magnetic flux ropes. When a flux rope destabilizes, it can either erupt and produce a coronal mass ejection or fail and collapse back towards the Sun. The prevailing belief is that the outcome of a given event is determined by a magnetohydrodynamic force imbalance called the torus instability. This belief is challenged, however, by observations indicating that torus-unstable flux ropes sometimes fail to erupt. This contradiction has not yet been resolved because of a lack of coronal magnetic field measurements and the limitations of idealized numerical modelling. Here we report the results of a laboratory experiment that reveal a previously unknown eruption criterion below which torus-unstable flux ropes fail to erupt. We find that such ‘failed torus’ events occur when the guide magnetic field (that is, the ambient field that runs toroidally along the flux rope) is strong enough to prevent the flux rope from kinking. Under these conditions, the guide field interacts with electric currents in the flux rope to produce a dynamic toroidal field tension force that halts the eruption. This magnetic tension force is missing from existing eruption models, which is why such models cannot explain or predict failed torus events.

  9. Translating Sustainability: The Design of a Secondary Charter School

    ERIC Educational Resources Information Center

    Hodgkinson, Todd Michael

    2011-01-01

    Although numerous efforts have been made to enact the concept of sustainability in schools around the world, a single, replicable model of sustainability education fails to exist. Without a replicable model to follow or adapt, educators looking to enact the concept of sustainability are left to their own devices for deciding what this orientation…

  10. INTEGRATED COASTAL RESERVE PLANNING: MAKING THE LAND-SEA CONNECTION

    EPA Science Inventory

    Land use, watershed processes, and coastal biodiversity can be strongly coupled. Land-sea interactions are ignored, however, when selecting terrestrial and marine reserves with existing models, with the risk that reserves will fail to achieve their conservation objectives. The co...

  11. Existential Assessment

    ERIC Educational Resources Information Center

    Dana, Richard H.; Leech, Shirley

    1974-01-01

    Present psychological assessment stems from a philosophy of science that values objectivity but fails to comprehend the existence of the person being evaluated. A humanistic-existential model shifts the focus from omnipotence to encounter and encourages client responsibility. Some pertinent assessment issues are formulated and specific instruments…

  12. A Multinomial Logit Model of Attrition that Distinguishes between Stopout and Dropout Behavior

    ERIC Educational Resources Information Center

    Stratton, Leslie S.; O'Toole, Dennis M.; Wetzel, James N.

    2004-01-01

    College attrition rates are of substantial concern to policy makers and economists interested in educational attainment and earnings opportunities. This is not surprising since nationwide, almost one-third of all first-time college students fail to return for their sophomore year. There exists a substantial body of literature seeking to model this…

  13. A dynamic magnetic tension force as the cause of failed solar eruptions

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

    Myers, Clayton E.; Yamada, Masaaki; Ji, Hantao

    Coronal mass ejections are solar eruptions driven by a sudden release of magnetic energy stored in the Sun's corona. In many cases, this magnetic energy is stored in long-lived, arched structures called magnetic flux ropes. When a flux rope destabilizes, it can either erupt and produce a coronal mass ejection or fail and collapse back towards the Sun. The prevailing belief is that the outcome of a given event is determined by a magnetohydrodynamic force imbalance called the torus instability. This belief is challenged, however, by observations indicating that torus-unstable flux ropes sometimes fail to erupt. This contradiction has notmore » yet been resolved because of a lack of coronal magnetic field measurements and the limitations of idealized numerical modelling. In this paper, we report the results of a laboratory experiment that reveal a previously unknown eruption criterion below which torus-unstable flux ropes fail to erupt. We find that such 'failed torus' events occur when the guide magnetic field (that is, the ambient field that runs toroidally along the flux rope) is strong enough to prevent the flux rope from kinking. Under these conditions, the guide field interacts with electric currents in the flux rope to produce a dynamic toroidal field tension force that halts the eruption. Lastly, this magnetic tension force is missing from existing eruption models, which is why such models cannot explain or predict failed torus events.« less

  14. A dynamic magnetic tension force as the cause of failed solar eruptions

    DOE PAGES

    Myers, Clayton E.; Yamada, Masaaki; Ji, Hantao; ...

    2015-12-23

    Coronal mass ejections are solar eruptions driven by a sudden release of magnetic energy stored in the Sun's corona. In many cases, this magnetic energy is stored in long-lived, arched structures called magnetic flux ropes. When a flux rope destabilizes, it can either erupt and produce a coronal mass ejection or fail and collapse back towards the Sun. The prevailing belief is that the outcome of a given event is determined by a magnetohydrodynamic force imbalance called the torus instability. This belief is challenged, however, by observations indicating that torus-unstable flux ropes sometimes fail to erupt. This contradiction has notmore » yet been resolved because of a lack of coronal magnetic field measurements and the limitations of idealized numerical modelling. In this paper, we report the results of a laboratory experiment that reveal a previously unknown eruption criterion below which torus-unstable flux ropes fail to erupt. We find that such 'failed torus' events occur when the guide magnetic field (that is, the ambient field that runs toroidally along the flux rope) is strong enough to prevent the flux rope from kinking. Under these conditions, the guide field interacts with electric currents in the flux rope to produce a dynamic toroidal field tension force that halts the eruption. Lastly, this magnetic tension force is missing from existing eruption models, which is why such models cannot explain or predict failed torus events.« less

  15. A biological compression model and its applications.

    PubMed

    Cao, Minh Duc; Dix, Trevor I; Allison, Lloyd

    2011-01-01

    A biological compression model, expert model, is presented which is superior to existing compression algorithms in both compression performance and speed. The model is able to compress whole eukaryotic genomes. Most importantly, the model provides a framework for knowledge discovery from biological data. It can be used for repeat element discovery, sequence alignment and phylogenetic analysis. We demonstrate that the model can handle statistically biased sequences and distantly related sequences where conventional knowledge discovery tools often fail.

  16. The Carnegie Mellon University Insert Project

    DTIC Science & Technology

    1997-02-01

    Real - Time Systems (INSERT) project under the DARPA Evolutionary Design for Complex Software (EDCS) Program. The INSERT team has completed an initial API definition and ported the existing real-time publication subscription group communication software to LynxOS 2.4, a POSIX.1b compliant OS. The distributed real-time publisher/subscriber communication model is now supported by a processor membership protocol which allows a node in the system to fail, or to rejoin the system later. When a node fails, all the publishers and subscribers on that node have to be

  17. The Objective Borderline method (OBM): a probability-based model for setting up an objective pass/fail cut-off score in medical programme assessments.

    PubMed

    Shulruf, Boaz; Turner, Rolf; Poole, Phillippa; Wilkinson, Tim

    2013-05-01

    The decision to pass or fail a medical student is a 'high stakes' one. The aim of this study is to introduce and demonstrate the feasibility and practicality of a new objective standard-setting method for determining the pass/fail cut-off score from borderline grades. Three methods for setting up pass/fail cut-off scores were compared: the Regression Method, the Borderline Group Method, and the new Objective Borderline Method (OBM). Using Year 5 students' OSCE results from one medical school we established the pass/fail cut-off scores by the abovementioned three methods. The comparison indicated that the pass/fail cut-off scores generated by the OBM were similar to those generated by the more established methods (0.840 ≤ r ≤ 0.998; p < .0001). Based on theoretical and empirical analysis, we suggest that the OBM has advantages over existing methods in that it combines objectivity, realism, robust empirical basis and, no less importantly, is simple to use.

  18. Cycle life test and failure model of nickel-hydrogen cells

    NASA Technical Reports Server (NTRS)

    Smithrick, J. J.

    1983-01-01

    Six ampere hour individual pressure vessel nickel hydrogen cells were charge/discharge cycled to failure. Failure as used here is defined to occur when the end of discharge voltage degraded to 0.9 volts. They were cycled under a low earth orbit cycle regime to a deep depth of discharge (80 percent of rated ampere hour capacity). Both cell designs were fabricated by the same manufacturer and represent current state of the art. A failure model was advanced which suggests both cell designs have inadequate volume tolerance characteristics. The limited existing data base at a deep depth of discharge (DOD) was expanded. Two cells of each design were cycled. One COMSAT cell failed at cycle 1712 and the other failed at cycle 1875. For the Air Force/Hughes cells, one cell failed at cycle 2250 and the other failed at cycle 2638. All cells, of both designs, failed due to low end of discharge voltage (0.9 volts). No cell failed due to electrical shorts. After cell failure, three different reconditioning tests (deep discharge, physical reorientation, and open circuit voltage stand) were conducted on all cells of each design. A fourth reconditioning test (electrolyte addition) was conducted on one cell of each design. In addition post cycle cell teardown and failure analysis were performed on the one cell of each design which did not have electrolyte added after failure.

  19. Enterprise Pattern: integrating the business process into a unified enterprise model of modern service company

    NASA Astrophysics Data System (ADS)

    Li, Ying; Luo, Zhiling; Yin, Jianwei; Xu, Lida; Yin, Yuyu; Wu, Zhaohui

    2017-01-01

    Modern service company (MSC), the enterprise involving special domains, such as the financial industry, information service industry and technology development industry, depends heavily on information technology. Modelling of such enterprise has attracted much research attention because it promises to help enterprise managers to analyse basic business strategies (e.g. the pricing strategy) and even optimise the business process (BP) to gain benefits. While the existing models proposed by economists cover the economic elements, they fail to address the basic BP and its relationship with the economic characteristics. Those proposed in computer science regardless of achieving great success in BP modelling perform poorly in supporting the economic analysis. Therefore, the existing approaches fail to satisfy the requirement of enterprise modelling for MSC, which demands simultaneous consideration of both economic analysing and business processing. In this article, we provide a unified enterprise modelling approach named Enterprise Pattern (EP) which bridges the gap between the BP model and the enterprise economic model of MSC. Proposing a language named Enterprise Pattern Description Language (EPDL) covering all the basic language elements of EP, we formulate the language syntaxes and two basic extraction rules assisting economic analysis. Furthermore, we extend Business Process Model and Notation (BPMN) to support EPDL, named BPMN for Enterprise Pattern (BPMN4EP). The example of mobile application platform is studied in detail for a better understanding of EPDL.

  20. Acceptance of internet-based hearing healthcare among adults who fail a hearing screening.

    PubMed

    Rothpletz, Ann M; Moore, Ashley N; Preminger, Jill E

    2016-09-01

    This study measured help-seeking readiness and acceptance of existing internet-based hearing healthcare (IHHC) websites among a group of older adults who failed a hearing screening (Phase 1). It also explored the effects of brief training on participants' acceptance of IHHC (Phase 2). Twenty-seven adults (age 55+) who failed a hearing screening participated. During Phase 1 participants were administered the University of Rhode Island Change Assessment (URICA) and patient technology acceptance model (PTAM) Questionnaire. During Phase 2 participants were randomly assigned to a training or control group. Training group participants attended an instructional class on existing IHHC websites. The control group received no training. The PTAM questionnaire was re-administered to both groups 4-6 weeks following the initial assessment. The majority of participants were either considering or preparing to do something about their hearing loss, and were generally accepting of IHHC websites (Phase 1). The participants who underwent brief IHHC training reported increases in hearing healthcare knowledge and slight improvements in computer self-efficacy (Phase 2). Older adults who fail hearing screenings may be good candidates for IHHC. The incorporation of a simple user-interface and short-term training may optimize the usability of future IHHC programs for this population.

  1. Authorizing the Foreign Language Students.

    ERIC Educational Resources Information Center

    Maxim, Hiram H.

    1998-01-01

    Reviews current practices in foreign-language teaching in light of Bourdieu's theories of language and power to show how failing to assess discursive intent prevents students from understanding strategic use of language. Bordieu's model is then proposed as the basis for pedagogy that authorizes students to use their existing cognitive skills in…

  2. Initial glenoid fixation using two different reverse shoulder designs with an equivalent center of rotation in a low-density and high-density bone substitute.

    PubMed

    Stroud, Nicholas J; DiPaola, Matthew J; Martin, Brian L; Steiler, Cindy A; Flurin, Pierre-Henri; Wright, Thomas W; Zuckerman, Joseph D; Roche, Christopher P

    2013-11-01

    Numerous glenoid implant designs have been introduced into the global marketplace in recent years; however, little comparative biomechanical data exist to substantiate one design consideration over another. This study dynamically evaluated reverse shoulder glenoid baseplate fixation and compared the initial fixation associated with 2 reverse shoulder designs having an equivalent center of rotation in low-density and high-density bone substitute substrates. Significant differences in fixation were observed between implant designs, where the circular-porous reverse shoulder was associated with approximately twice the micromotion per equivalent test than the oblong-grit-blasted design. Additionally, 6 of the 7 circular-porous reverse shoulders failed catastrophically in the low-density bone model at an average of 2603 ± 981 cycles. None of the oblong-grit-blasted designs failed in the low-or high-density bone models and none of the circular-porous designs failed in the high-density bone models after 10,000 cycles of loading. These results demonstrate that significant differences in initial fixation exist between reverse shoulder implants having an equivalent center of rotation and suggest that design parameters, other than the position of the center of rotation, significantly affect fixation in low-density and high-density polyurethane bone substitutes. Subtle changes in glenoid baseplate design can dramatically affect fixation, particularly in low-density bone substitutes that are intended to simulate the bone quality of the recipient population for reverse shoulders. Copyright © 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  3. Improved dual-porosity models for petrophysical analysis of vuggy reservoirs

    NASA Astrophysics Data System (ADS)

    Wang, Haitao

    2017-08-01

    A new vug interconnection, isolated vug (IVG), was investigated through resistivity modeling and the dual-porosity model for connected vug (CVG) vuggy reservoirs was tested. The vuggy models were built by pore-scale modeling, and their electrical resistivity was calculated by the finite difference method. For CVG vuggy reservoirs, the CVG reduced formation factors and increased the porosity exponents, and the existing dual-porosity model failed to match these results. Based on the existing dual-porosity model, a conceptual dual-porosity model for CVG was developed by introducing a decoupled term to reduce the resistivity of the model. For IVG vuggy reservoirs, IVG increased the formation factors and porosity exponents. The existing dual-porosity model succeeded due to accurate calculation of the formation factors of the deformed interparticle porous media caused by the insertion of the IVG. Based on the existing dual-porosity model, a new porosity model for IVG vuggy reservoirs was developed by simultaneously recalculating the formation factors of the altered interparticle pore-scale models. The formation factors and porosity exponents from the improved and extended dual-porosity models for CVG and IVG vuggy reservoirs well matched the simulated formation factors and porosity exponents. This work is helpful for understanding the influence of connected and disconnected vugs on resistivity factors—an issue of particular importance in carbonates.

  4. Intrinsic two-dimensional features as textons

    NASA Technical Reports Server (NTRS)

    Barth, E.; Zetzsche, C.; Rentschler, I.

    1998-01-01

    We suggest that intrinsic two-dimensional (i2D) features, computationally defined as the outputs of nonlinear operators that model the activity of end-stopped neurons, play a role in preattentive texture discrimination. We first show that for discriminable textures with identical power spectra the predictions of traditional models depend on the type of nonlinearity and fail for energy measures. We then argue that the concept of intrinsic dimensionality, and the existence of end-stopped neurons, can help us to understand the role of the nonlinearities. Furthermore, we show examples in which models without strong i2D selectivity fail to predict the correct ranking order of perceptual segregation. Our arguments regarding the importance of i2D features resemble the arguments of Julesz and co-workers regarding textons such as terminators and crossings. However, we provide a computational framework that identifies textons with the outputs of nonlinear operators that are selective to i2D features.

  5. 40 CFR 152.99 - Petitions to cancel registration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... failed to comply with the procedure for showing that a data gap exists. (v) The applicant has improperly certified that a data gap exists. An original data submitter who has failed without good cause to respond to an applicant's request for confirmation of a data gap may not petition the Agency for review on this...

  6. Examining the Implementation of Two Co-Teaching Models: Team Teaching and Station Teaching

    ERIC Educational Resources Information Center

    Gurgur, Hasan; Uzuner, Yildiz

    2011-01-01

    In Turkey, the number of students in mainstream education is increasing, and a support service does not exist even though mainstreaming has been implemented for many years. Therefore, within this system, many students with special needs are failing. Thus, there is a need for evidence-based research projects concerning the ways of supporting these…

  7. Rabbits killing birds revisited.

    PubMed

    Zhang, Jimin; Fan, Meng; Kuang, Yang

    2006-09-01

    We formulate and study a three-species population model consisting of an endemic prey (bird), an alien prey (rabbit) and an alien predator (cat). Our model overcomes several model construction problems in existing models. Moreover, our model generates richer, more reasonable and realistic dynamics. We explore the possible control strategies to save or restore the bird by controlling or eliminating the rabbit or the cat when the bird is endangered. We confirm the existence of the hyperpredation phenomenon, which is a big potential threat to most endemic prey. Specifically, we show that, in an endemic prey-alien prey-alien predator system, eradication of introduced predators such as the cat alone is not always the best solution to protect endemic insular prey since predator control may fail to protect the indigenous prey when the control of the introduced prey is not carried out simultaneously.

  8. 78 FR 6772 - Failure To File Gain Recognition Agreements and Other Required Filings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-31

    ... regulations that would amend the existing rules governing the consequences to U.S. persons for failing to file... current law, if a U.S. transferor fails to timely file an initial GRA, or fails to comply in any material... fails to timely file an annual certification), the U.S. transferor is subject to full gain recognition...

  9. The relevance of human stem cell-derived organoid models for epithelial translational medicine

    PubMed Central

    Hynds, Robert E.; Giangreco, Adam

    2014-01-01

    Epithelial organ remodeling is a major contributing factor to worldwide death and disease, costing healthcare systems billions of dollars every year. Despite this, most fundamental epithelial organ research fails to produce new therapies and mortality rates for epithelial organ diseases remain unacceptably high. In large part, this failure in translating basic epithelial research into clinical therapy is due to a lack of relevance in existing preclinical models. To correct this, new models are required that improve preclinical target identification, pharmacological lead validation, and compound optimization. In this review, we discuss the relevance of human stem cell-derived, three-dimensional organoid models for addressing each of these challenges. We highlight the advantages of stem cell-derived organoid models over existing culture systems, discuss recent advances in epithelial tissue-specific organoids, and present a paradigm for using organoid models in human translational medicine. PMID:23203919

  10. Analysis of the Boeing 747-100 using CEASIOM

    NASA Astrophysics Data System (ADS)

    Richardson, Thomas S.; Beaverstock, Chris; Isikveren, Askin; Meheri, Alireza; Badcock, Ken; Da Ronch, Andrea

    2011-11-01

    One of the requirements for the SimSAC project was to use existing aircraft to act as benchmarks for comparison with CEASIOM generated models. Within this paper, results are given for one of these examples, the Boeing 747-100. This aircraft was selected because a complete dataset exists in the open domain, which can be used to validate SimSAC generated data. The purpose of this paper is to both give confidence in, and to demonstrate the capabilities of, the CEASIOM environment when used for preliminary aircraft and control system design. CEASIOM is the result of the integration of a set of sophisticated tools by the European Union funded, Framework 6 SimSAC program. The first part of this paper presents a comparison of the aerodynamic results for each of the solvers available within CEASIOM together with data from the 747-100 model published by NASA. The resulting nonlinear model is then trimmed and analysed using the Flight Control System Designer Toolkit (FCSDT) module. In the final section of the paper a state-feedback controller is designed within CEASIOM in order to modify the longitudinal dynamics of the aircraft. The open and closed loop models are subsequently evaluated with selected failed aerodynamic surfaces and for the case of a single failed engine. Through these results, the CEASIOM software suite is shown to be able to generate excellent quality adaptive-fidelity aerodynamic data. This data is contained within a full nonlinear aircraft model to which linear analysis and control system design can be easily applied.

  11. 78 FR 25115 - Self-Regulatory Organizations; Fixed Income Clearing Corporation; Notice of Filing of Proposed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-29

    ... Amending the Mortgage-Backed Securities Division Fails Charge Rule To Reflect Recommendation of the... change is to amend the existing fails charge rule in FICC's Mortgage-Backed Securities Division (``MBSD... (``TMPG'') relating to the removal of the resolution period for fails charges.\\3\\ \\3\\ The text of the...

  12. Cooperative inference: Features, objects, and collections.

    PubMed

    Searcy, Sophia Ray; Shafto, Patrick

    2016-10-01

    Cooperation plays a central role in theories of development, learning, cultural evolution, and education. We argue that existing models of learning from cooperative informants have fundamental limitations that prevent them from explaining how cooperation benefits learning. First, existing models are shown to be computationally intractable, suggesting that they cannot apply to realistic learning problems. Second, existing models assume a priori agreement about which concepts are favored in learning, which leads to a conundrum: Learning fails without precise agreement on bias yet there is no single rational choice. We introduce cooperative inference, a novel framework for cooperation in concept learning, which resolves these limitations. Cooperative inference generalizes the notion of cooperation used in previous models from omission of labeled objects to the omission values of features, labels for objects, and labels for collections of objects. The result is an approach that is computationally tractable, does not require a priori agreement about biases, applies to both Boolean and first-order concepts, and begins to approximate the richness of real-world concept learning problems. We conclude by discussing relations to and implications for existing theories of cognition, cognitive development, and cultural evolution. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  13. Open-source approaches for the repurposing of existing or failed candidate drugs: learning from and applying the lessons across diseases

    PubMed Central

    Allarakhia, Minna

    2013-01-01

    Repurposing has the objective of targeting existing drugs and failed, abandoned, or yet-to-be-pursued clinical candidates to new disease areas. The open-source model permits for the sharing of data, resources, compounds, clinical molecules, small libraries, and screening platforms to cost-effectively advance old drugs and/or candidates into clinical re-development. Clearly, at the core of drug-repurposing activities is collaboration, in many cases progressing beyond the open sharing of resources, technology, and intellectual property, to the sharing of facilities and joint program development to foster drug-repurposing human-capacity development. A variety of initiatives under way for drug repurposing, including those targeting rare and neglected diseases, are discussed in this review and provide insight into the stakeholders engaged in drug-repurposing discovery, the models of collaboration used, the intellectual property-management policies crafted, and human capacity developed. In the case of neglected tropical diseases, it is suggested that the development of human capital be a central aspect of drug-repurposing programs. Open-source models can support human-capital development through collaborative data generation, open compound access, open and collaborative screening, preclinical and possibly clinical studies. Given the urgency of drug development for neglected tropical diseases, the review suggests elements from current repurposing programs be extended to the neglected tropical diseases arena. PMID:23966771

  14. Open-source approaches for the repurposing of existing or failed candidate drugs: learning from and applying the lessons across diseases.

    PubMed

    Allarakhia, Minna

    2013-01-01

    Repurposing has the objective of targeting existing drugs and failed, abandoned, or yet-to-be-pursued clinical candidates to new disease areas. The open-source model permits for the sharing of data, resources, compounds, clinical molecules, small libraries, and screening platforms to cost-effectively advance old drugs and/or candidates into clinical re-development. Clearly, at the core of drug-repurposing activities is collaboration, in many cases progressing beyond the open sharing of resources, technology, and intellectual property, to the sharing of facilities and joint program development to foster drug-repurposing human-capacity development. A variety of initiatives under way for drug repurposing, including those targeting rare and neglected diseases, are discussed in this review and provide insight into the stakeholders engaged in drug-repurposing discovery, the models of collaboration used, the intellectual property-management policies crafted, and human capacity developed. In the case of neglected tropical diseases, it is suggested that the development of human capital be a central aspect of drug-repurposing programs. Open-source models can support human-capital development through collaborative data generation, open compound access, open and collaborative screening, preclinical and possibly clinical studies. Given the urgency of drug development for neglected tropical diseases, the review suggests elements from current repurposing programs be extended to the neglected tropical diseases arena.

  15. The generalization of the Mermin-Wagner theorem and the possibility of long-range order in the isotropic discrete one-dimensional quantum Heisenberg model

    NASA Astrophysics Data System (ADS)

    Rudoy, Yu. G.; Kotelnikova, O. A.

    2012-10-01

    The problem of existence of long-range order in the isotropic quantum Heisenberg model on the D=1 lattice is reconsidered in view of the possibility of sufficiently slow decaying exchange interaction with infinite effective radius. It is shown that the macrosopic arguments given by Landau and Lifshitz and then supported microscopically by Mermin and Wagner fail for this case so that the non-zero spontaneous magnetization may yet exist. This result was anticipated by Thouless on the grounds of phenomenological analysis, and we give its microscopic foundation, which amounts to the generalization of Mermin-Wagner theorem for the case of the infinite second moment of the exchange interaction. Two well known in lattice statistics models - i.e., Kac-I and Kac-II - illustrate our results.

  16. 76 FR 71991 - Agency Information Collection Activities: Proposed Collection; Comment Request, Federal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-21

    ... order form a decision as to whether or not a condition of ``decline or fail'' exists at the State and... cases where State and local governments have declined or failed to prepare emergency plans. To implement... procedures for a licensee submission of a certification of ``decline or fail'', and for FEMA determination...

  17. Improvement of the low frequency oscillation model for Hall thrusters

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

    Wang, Chunsheng, E-mail: wangcs@hit.edu.cn; Wang, Huashan

    2016-08-15

    The low frequency oscillation of the discharge current in Hall thrusters is a major aspect of these devices that requires further study. While the existing model captures the ionization mechanism of the low frequency oscillation, it unfortunately fails to express the dynamic characteristics of the ion acceleration. The analysis in this paper shows this is because of the simplification of the electron equation, which affects both the electric field distribution and the ion acceleration process. Additionally, the electron density equation is revised and a new model that is based on the physical properties of ion movement is proposed.

  18. Low Activation Joining of SiC/SiC Composites for Fusion Applications: Modeling Miniature Torsion Tests with Elastic and Elastic-Plastic Models

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

    Henager, Charles H.; Nguyen, Ba Nghiep; Kurtz, Richard J.

    2015-06-30

    The international fusion community designed miniature torsion specimens for joint testing and irradiation in test reactors with limited irradiation volumes since SiC and SiC-composites used in fission or fusion environments require joining methods for assembling systems. Torsion specimens fail out-of-plane when joints are strong and when elastic moduli are comparable to SiC, which causes difficulties in determining shear strengths for many joints or for comparing unirradiated and irradiated joints. A finite element damage model was developed to treat elastic joints such as SiC/Ti3SiC2+SiC and elastic-plastic joints such as SiC/epoxy and steel/epoxy. The model uses constitutive shear data and is validatedmore » using epoxy joint data. The elastic model indicates fracture is likely to occur within the joined pieces to cause out-of-plane failures for miniature torsion specimens when a certain modulus and strength ratio between the joint material and the joined material exists. Lower modulus epoxy joints always fail in plane and provide good model validation.« less

  19. Failure to Fail in a Final Pre-Service Teaching Practicum

    ERIC Educational Resources Information Center

    Danyluk, Patricia J.; Luhanga, Florence; Gwekwerere, Yovita N.; MacEwan, Leigh; Larocque, Sylvie

    2015-01-01

    This article presents a Canadian perspective on the issue of failure to fail in Bachelor of Education programs. The issue of failure to fail in Bachelor of Education programs is one that had not been explored in any great detail. What literature does exist focuses on the strain that a teacher experiences when s/he mentors a student teacher…

  20. Beyond Failure: Potentially Mitigating Failed Author Searches in the Online Library Catalog through the Use of Linked Data

    ERIC Educational Resources Information Center

    Moulaison, Heather Lea; Stanley, Susan Nicole

    2013-01-01

    Linked data stores house vetted content that can supplement the information available through online library catalogs, potentially mitigating failed author searches if information about the author exists in linked data formats. In this case study, a total of 689 failed author index queries from a large Midwestern academic library's online library…

  1. Cascading failures in interdependent systems under a flow redistribution model

    NASA Astrophysics Data System (ADS)

    Zhang, Yingrui; Arenas, Alex; Yaǧan, Osman

    2018-02-01

    Robustness and cascading failures in interdependent systems has been an active research field in the past decade. However, most existing works use percolation-based models where only the largest component of each network remains functional throughout the cascade. Although suitable for communication networks, this assumption fails to capture the dependencies in systems carrying a flow (e.g., power systems, road transportation networks), where cascading failures are often triggered by redistribution of flows leading to overloading of lines. Here, we consider a model consisting of systems A and B with initial line loads and capacities given by {LA,i,CA ,i} i =1 n and {LB,i,CB ,i} i =1 n, respectively. When a line fails in system A , a fraction of its load is redistributed to alive lines in B , while remaining (1 -a ) fraction is redistributed equally among all functional lines in A ; a line failure in B is treated similarly with b giving the fraction to be redistributed to A . We give a thorough analysis of cascading failures of this model initiated by a random attack targeting p1 fraction of lines in A and p2 fraction in B . We show that (i) the model captures the real-world phenomenon of unexpected large scale cascades and exhibits interesting transition behavior: the final collapse is always first order, but it can be preceded by a sequence of first- and second-order transitions; (ii) network robustness tightly depends on the coupling coefficients a and b , and robustness is maximized at non-trivial a ,b values in general; (iii) unlike most existing models, interdependence has a multifaceted impact on system robustness in that interdependency can lead to an improved robustness for each individual network.

  2. Cascading failures in interdependent systems under a flow redistribution model.

    PubMed

    Zhang, Yingrui; Arenas, Alex; Yağan, Osman

    2018-02-01

    Robustness and cascading failures in interdependent systems has been an active research field in the past decade. However, most existing works use percolation-based models where only the largest component of each network remains functional throughout the cascade. Although suitable for communication networks, this assumption fails to capture the dependencies in systems carrying a flow (e.g., power systems, road transportation networks), where cascading failures are often triggered by redistribution of flows leading to overloading of lines. Here, we consider a model consisting of systems A and B with initial line loads and capacities given by {L_{A,i},C_{A,i}}_{i=1}^{n} and {L_{B,i},C_{B,i}}_{i=1}^{n}, respectively. When a line fails in system A, a fraction of its load is redistributed to alive lines in B, while remaining (1-a) fraction is redistributed equally among all functional lines in A; a line failure in B is treated similarly with b giving the fraction to be redistributed to A. We give a thorough analysis of cascading failures of this model initiated by a random attack targeting p_{1} fraction of lines in A and p_{2} fraction in B. We show that (i) the model captures the real-world phenomenon of unexpected large scale cascades and exhibits interesting transition behavior: the final collapse is always first order, but it can be preceded by a sequence of first- and second-order transitions; (ii) network robustness tightly depends on the coupling coefficients a and b, and robustness is maximized at non-trivial a,b values in general; (iii) unlike most existing models, interdependence has a multifaceted impact on system robustness in that interdependency can lead to an improved robustness for each individual network.

  3. Propulsion system/flight control integration for supersonic aircraft

    NASA Technical Reports Server (NTRS)

    Reukauf, P. J.; Burcham, F. W., Jr.

    1976-01-01

    Digital integrated control systems are studied. Such systems allow minimization of undesirable interactions while maximizing performance at all flight conditions. One such program is the YF-12 cooperative control program. The existing analog air data computer, autothrottle, autopilot, and inlet control systems are converted to digital systems by using a general purpose airborne computer and interface unit. Existing control laws are programed and tested in flight. Integrated control laws, derived using accurate mathematical models of the airplane and propulsion system in conjunction with modern control techniques, are tested in flight. Analysis indicates that an integrated autothrottle autopilot gives good flight path control and that observers are used to replace failed sensors.

  4. Silica Glass Fibers : Modes Of Degradation And Thoughts On Protection

    NASA Astrophysics Data System (ADS)

    Kruger, Albert A.; Mularie, William M.

    1984-03-01

    The widely held explanation for mechanical failure of silicate glasses rests upon the existence of Griffith-flaw and the associated free-ion diffusion concept used to model crack growth. However, this theory has consistently failed to provide complete agreement with the experimental results known to those "schooled" in the poignant literature. This dilemma coupled with the reports of single-valued strengths in fibers cannot be rationalized by the modification of the intrinsic Griffith-flaw distribution to essentially a delta function (this violates entropy). It is for these reasons that the field-enhanced ion diffusion model has been introduced. The inclusion of a term for electrostatic potential in the solution of Fick's second law is shown to be consistent with the experimental results in the existing literature. The results of the work presented herein provide further support of the proposed model, and the implied consequences of chemical corrosion in glass which results in its subsequent failure.

  5. Simulating fail-stop in asynchronous distributed systems

    NASA Technical Reports Server (NTRS)

    Sabel, Laura; Marzullo, Keith

    1994-01-01

    The fail-stop failure model appears frequently in the distributed systems literature. However, in an asynchronous distributed system, the fail-stop model cannot be implemented. In particular, it is impossible to reliably detect crash failures in an asynchronous system. In this paper, we show that it is possible to specify and implement a failure model that is indistinguishable from the fail-stop model from the point of view of any process within an asynchronous system. We give necessary conditions for a failure model to be indistinguishable from the fail-stop model, and derive lower bounds on the amount of process replication needed to implement such a failure model. We present a simple one-round protocol for implementing one such failure model, which we call simulated fail-stop.

  6. Exploring the issue of failure to fail in a nursing program.

    PubMed

    Larocque, Sylvie; Luhanga, Florence Loyce

    2013-05-18

    A study using a qualitative descriptive design was undertaken to explore the issue of "failure to fail" in a nursing program. Individual in-depth interviews were conducted with nursing university faculty members, preceptors, and faculty advisors (n=13). Content analysis was used to analyze the data. Results indicate that: (a) failing a student is a difficult process; (b) both academic and emotional support are required for students and preceptors and faculty advisors; (c) there are consequences for programs, faculty, and students when a student has failed a placement; (d) at times, personal, professional, and structural reasons exist for failing to fail a student; and (e) the reputation of the professional program can be diminished as a result of failing to fail a student. Recommendations for improving assessment, evaluation, and intervention with a failing student include documentation, communication, and support. These findings have implications for improving the quality of clinical experiences.

  7. A Two-Phase Space Resection Model for Accurate Topographic Reconstruction from Lunar Imagery with PushbroomScanners

    PubMed Central

    Xu, Xuemiao; Zhang, Huaidong; Han, Guoqiang; Kwan, Kin Chung; Pang, Wai-Man; Fang, Jiaming; Zhao, Gansen

    2016-01-01

    Exterior orientation parameters’ (EOP) estimation using space resection plays an important role in topographic reconstruction for push broom scanners. However, existing models of space resection are highly sensitive to errors in data. Unfortunately, for lunar imagery, the altitude data at the ground control points (GCPs) for space resection are error-prone. Thus, existing models fail to produce reliable EOPs. Motivated by a finding that for push broom scanners, angular rotations of EOPs can be estimated independent of the altitude data and only involving the geographic data at the GCPs, which are already provided, hence, we divide the modeling of space resection into two phases. Firstly, we estimate the angular rotations based on the reliable geographic data using our proposed mathematical model. Then, with the accurate angular rotations, the collinear equations for space resection are simplified into a linear problem, and the global optimal solution for the spatial position of EOPs can always be achieved. Moreover, a certainty term is integrated to penalize the unreliable altitude data for increasing the error tolerance. Experimental results evidence that our model can obtain more accurate EOPs and topographic maps not only for the simulated data, but also for the real data from Chang’E-1, compared to the existing space resection model. PMID:27077855

  8. A Two-Phase Space Resection Model for Accurate Topographic Reconstruction from Lunar Imagery with PushbroomScanners.

    PubMed

    Xu, Xuemiao; Zhang, Huaidong; Han, Guoqiang; Kwan, Kin Chung; Pang, Wai-Man; Fang, Jiaming; Zhao, Gansen

    2016-04-11

    Exterior orientation parameters' (EOP) estimation using space resection plays an important role in topographic reconstruction for push broom scanners. However, existing models of space resection are highly sensitive to errors in data. Unfortunately, for lunar imagery, the altitude data at the ground control points (GCPs) for space resection are error-prone. Thus, existing models fail to produce reliable EOPs. Motivated by a finding that for push broom scanners, angular rotations of EOPs can be estimated independent of the altitude data and only involving the geographic data at the GCPs, which are already provided, hence, we divide the modeling of space resection into two phases. Firstly, we estimate the angular rotations based on the reliable geographic data using our proposed mathematical model. Then, with the accurate angular rotations, the collinear equations for space resection are simplified into a linear problem, and the global optimal solution for the spatial position of EOPs can always be achieved. Moreover, a certainty term is integrated to penalize the unreliable altitude data for increasing the error tolerance. Experimental results evidence that our model can obtain more accurate EOPs and topographic maps not only for the simulated data, but also for the real data from Chang'E-1, compared to the existing space resection model.

  9. Failing the Future: Three Unsuccessful Attempts to Replicate Bem's ‘Retroactive Facilitation of Recall’ Effect

    PubMed Central

    Ritchie, Stuart J.; Wiseman, Richard; French, Christopher C.

    2012-01-01

    Nine recently reported parapsychological experiments appear to support the existence of precognition. We describe three pre-registered independent attempts to exactly replicate one of these experiments, ‘retroactive facilitation of recall’, which examines whether performance on a memory test can be influenced by a post-test exercise. All three replication attempts failed to produce significant effects (combined n = 150; combined p = .83, one-tailed) and thus do not support the existence of psychic ability. PMID:22432019

  10. What is a "good enough" termination?

    PubMed

    Gabbard, Glen O

    2009-06-01

    In Freud's technique papers, he failed to develop a systematic approach to termination. Much of the existing literature is based on psychoanalytic mythologies about the way patients are expected to end analysis. The models described in the literature are often starkly at odds with what one sees in clinical practice. A wish for idealized versions of termination underlies much of what has been written, and we need to shift to a conceptual model involving "good enough" termination. A number of different endings to psychoanalysis may, in the long run, lead to productive outcomes; these models are examined, as are various approaches to the dilemmas presented at the time of termination.

  11. MSC/NASTRAN Stress Analysis of Complete Models Subjected to Random and Quasi-Static Loads

    NASA Technical Reports Server (NTRS)

    Hampton, Roy W.

    2000-01-01

    Space payloads, such as those which fly on the Space Shuttle in Spacelab, are designed to withstand dynamic loads which consist of combined acoustic random loads and quasi-static acceleration loads. Methods for computing the payload stresses due to these loads are well known and appear in texts and NASA documents, but typically involve approximations such as the Miles' equation, as well as possible adjustments based on "modal participation factors." Alternatively, an existing capability in MSC/NASTRAN may be used to output exact root mean square [rms] stresses due to the random loads for any specified elements in the Finite Element Model. However, it is time consuming to use this methodology to obtain the rms stresses for the complete structural model and then combine them with the quasi-static loading induced stresses. Special processing was developed as described here to perform the stress analysis of all elements in the model using existing MSC/NASTRAN and MSC/PATRAN and UNIX utilities. Fail-safe and buckling analyses applications are also described.

  12. Filling Terrorism Gaps: VEOs, Evaluating Databases, and Applying Risk Terrain Modeling to Terrorism

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

    Hagan, Ross F.

    2016-08-29

    This paper aims to address three issues: the lack of literature differentiating terrorism and violent extremist organizations (VEOs), terrorism incident databases, and the applicability of Risk Terrain Modeling (RTM) to terrorism. Current open source literature and publicly available government sources do not differentiate between terrorism and VEOs; furthermore, they fail to define them. Addressing the lack of a comprehensive comparison of existing terrorism data sources, a matrix comparing a dozen terrorism databases is constructed, providing insight toward the array of data available. RTM, a method for spatial risk analysis at a micro level, has some applicability to terrorism research, particularlymore » for studies looking at risk indicators of terrorism. Leveraging attack data from multiple databases, combined with RTM, offers one avenue for closing existing research gaps in terrorism literature.« less

  13. Recycled Bricks: Exploring Opportunities to Reintegrate Returning American Foreign Fighters Using Existing Models

    DTIC Science & Technology

    2016-12-01

    Fighter Travel, 6. 16 Ibid., 6–15. 17 Ibid., 13. 5 United States failed to stop Americans from going abroad to become foreign fighters, and made 32...ethnicity only possess meaning because they connect people socially.130 The different categories that American Muslims classify themselves demonstrate the...Identity.” 133 Ibid., 66. 34 An example is found in American Muslims; they identify all Americans as part of their national in-group, but when

  14. Structure of field rotating disturbances in warm plasma

    NASA Technical Reports Server (NTRS)

    Wolfson, R.

    1982-01-01

    A model in which thermal effects are simulated through use of a multibeam plasma distribution function is developed and investigated to see if solutions which take an initially uniform magnetized plasma to a new uniform state with different field orientation are possible. The momentum conservation integrals are found to admit two classes of such solutions, but only one class exhibits appropriate asymptotic behavior. Extensive numerical integrations have failed to demonstrate the existence of the desired solutions.

  15. The directed mutation controversy and neo-Darwinism.

    PubMed

    Lenski, R E; Mittler, J E

    1993-01-08

    According to neo-Darwinian theory, random mutation produces genetic differences among organisms whereas natural selection tends to increase the frequency of advantageous alleles. However, several recent papers claim that certain mutations in bacteria and yeast occur at much higher rates specifically when the mutant phenotypes are advantageous. Various molecular models have been proposed that might explain these directed mutations, but the models have not been confirmed. Critics contend that studies purporting to demonstrate directed mutation lack certain controls and fail to account adequately for population dynamics. Further experiments that address these criticisms do not support the existence of directed mutations.

  16. Torching the Haystack: modelling fast-fail strategies in drug development.

    PubMed

    Lendrem, Dennis W; Lendrem, B Clare

    2013-04-01

    By quickly clearing the development pipeline of failing or marginal products, fast-fail strategies release resources to focus on more promising molecules. The Quick-Kill model of drug development demonstrates that fast-fail strategies will: (1) reduce the expected time to market; (2) reduce expected R&D costs; and (3) increase R&D productivity. This paper outlines the model and demonstrates the impact of fast-fail strategies. The model is illustrated with costs and risks data from pharmaceutical and biopharmaceutical companies. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Diagnosing a Failed Proof in Fault-Tolerance: A Disproving Challenge Problem

    NASA Technical Reports Server (NTRS)

    Pike, Lee; Miner, Paul; Torres-Pomales, Wilfredo

    2006-01-01

    This paper proposes a challenge problem in disproving. We describe a fault-tolerant distributed protocol designed at NASA for use in a fly-by-wire system for next-generation commercial aircraft. An early design of the protocol contains a subtle bug that is highly unlikely to be caught in fault injection testing. We describe a failed proof of the protocol's correctness in a mechanical theorem prover (PVS) with a complex unfinished proof conjecture. We use a model checking suite (SAL) to generate a concrete counterexample to the unproven conjecture to demonstrate the existence of a bug. However, we argue that the effort required in our approach is too high and propose what conditions a better solution would satisfy. We carefully describe the protocol and bug to provide a challenging but feasible case study for disproving research.

  18. Dimer-based model for heptaspanning membrane receptors.

    PubMed

    Franco, Rafael; Casadó, Vicent; Mallol, Josefa; Ferré, Sergi; Fuxe, Kjell; Cortés, Antonio; Ciruela, Francisco; Lluis, Carmen; Canela, Enric I

    2005-07-01

    The existence of intramembrane receptor-receptor interactions for heptaspanning membrane receptors is now fully accepted, but a model considering dimers as the basic unit that binds to two ligand molecules is lacking. Here, we propose a two-state-dimer model in which the ligand-induced conformational changes from one component of the dimer are communicated to the other. Our model predicts cooperativity in binding, which is relevant because the other current models fail to address this phenomenon satisfactorily. Our two-state-dimer model also predicts the variety of responses elicited by full or partial agonists, neutral antagonists and inverse agonists. This model can aid our understanding of the operation of heptaspanning receptors and receptor channels, and, potentially, be important for improving the treatment of cardiovascular, neurological and neuropsychyatric diseases.

  19. Structured filtering

    NASA Astrophysics Data System (ADS)

    Granade, Christopher; Wiebe, Nathan

    2017-08-01

    A major challenge facing existing sequential Monte Carlo methods for parameter estimation in physics stems from the inability of existing approaches to robustly deal with experiments that have different mechanisms that yield the results with equivalent probability. We address this problem here by proposing a form of particle filtering that clusters the particles that comprise the sequential Monte Carlo approximation to the posterior before applying a resampler. Through a new graphical approach to thinking about such models, we are able to devise an artificial-intelligence based strategy that automatically learns the shape and number of the clusters in the support of the posterior. We demonstrate the power of our approach by applying it to randomized gap estimation and a form of low circuit-depth phase estimation where existing methods from the physics literature either exhibit much worse performance or even fail completely.

  20. 5 CFR 537.109 - Employee reimbursements to the Government.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... existing service agreement to provide additional student loan repayment benefits for additional service (as... initial service period but fails to complete the additional service period, he or she is required to... additional service period. (d) If an employee fails to reimburse the paying agency for the amount owed under...

  1. The search for failed supernovae with the Large Binocular Telescope: constraints from 7 yr of data

    NASA Astrophysics Data System (ADS)

    Adams, S. M.; Kochanek, C. S.; Gerke, J. R.; Stanek, K. Z.

    2017-08-01

    We report updated results for the first 7 yr of our programme to monitor 27 galaxies within 10 Mpc using the Large Binocular Telescope to search for failed supernovae (SNe) - core collapses of massive stars that form black holes without luminous SNe. In the new data, we identify no new compelling candidates and confirm the existing candidate. Given the six successful core-collapse SNe in the sample and one likely failed SN, the implied fraction of core collapses that result in failed SNe is f=0.14^{+0.33}_{-0.10} at 90 per cent confidence. If the current candidate is a failed SN, the fraction of failed SN naturally explains the missing high-mass red supergiants SN progenitors and the black hole mass function. If the current candidate is ultimately rejected, the data imply a 90 per cent confidence upper limit on the failed SN fraction of f < 0.35.

  2. Weak and Failing States: Evolving Security Threats and U.S. Policy

    DTIC Science & Technology

    2007-11-15

    operate in both “ caves ” (i.e., failed states, where militant groups can exist CRS-6 11 Rabasa (2007), ibid. 12 U.S. Government Interagency Working Group...Support to Low-Income Countries Under Stress (Washington, DC: The World Bank, 2006); Chauvet and Collier, “Helping Hand? Aid to Failing States...Oxford University Working Paper (2006). 24 See Chauvet and Collier (2004), op. cit.; Francois Bourguignon, “Broadening Progress Toward the MDGs,” Speech

  3. Weak and Failing States: Evolving Security Threats and U.S. Policy

    DTIC Science & Technology

    2007-11-15

    operate in both “ caves ” (i.e., failed states, where militant groups can exist CRS-6 11 Rabasa (2007), ibid. 12 U.S. Government Interagency Working Group...Support to Low-Income Countries Under Stress (Washington, DC: The World Bank, 2006); Chauvet and Collier, “Helping Hand? Aid to Failing States,” Oxford...University Working Paper (2006). 24 See Chauvet and Collier (2004), op. cit.; Francois Bourguignon, “Broadening Progress Toward the MDGs,” Speech

  4. Weak and Failing States: Evolving Security Threats and U.S. Policy

    DTIC Science & Technology

    2008-08-28

    terrorists operate in both “ caves ” (i.e., failed states, where militant groups can exist with impunity) and “condos” (i.e., states that have the...of World Bank Support to Low-Income Countries Under Stress (Washington, DC: The World Bank, 2006); Chauvet and Collier, “Helping Hand? Aid to Failing...States,” Oxford University Working Paper (2006). 29 See Chauvet and Collier (2004), op. cit.; Francois Bourguignon, “Broadening Progress Toward the

  5. Additive Manufacturing of Molds for Fabrication of Insulated Concrete Block

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

    Love, Lonnie J.; Lloyd, Peter D.

    ORNL worked with concrete block manufacturer, NRG Insulated Block, to demonstrate additive manufacturing of a multi-component block mold for its line of insulated blocks. Solid models of the mold parts were constructed from existing two-dimensional drawings and the parts were fabricated on a Stratasys Fortus 900 using ULTEM 9085. Block mold parts were delivered to NRG and installed on one of their fabrication lines. While form and fit were acceptable, the molds failed to function during NRG’s testing.

  6. The admissible portfolio selection problem with transaction costs and an improved PSO algorithm

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Zhang, Wei-Guo

    2010-05-01

    In this paper, we discuss the portfolio selection problem with transaction costs under the assumption that there exist admissible errors on expected returns and risks of assets. We propose a new admissible efficient portfolio selection model and design an improved particle swarm optimization (PSO) algorithm because traditional optimization algorithms fail to work efficiently for our proposed problem. Finally, we offer a numerical example to illustrate the proposed effective approaches and compare the admissible portfolio efficient frontiers under different constraints.

  7. Onion-shell model for cosmic ray electrons and radio synchrotron emission in supernova remnants

    NASA Technical Reports Server (NTRS)

    Beck, R.; Drury, L. O.; Voelk, H. J.; Bogdan, T. J.

    1985-01-01

    The spectrum of cosmic ray electrons, accelerated in the shock front of a supernova remnant (SNR), is calculated in the test-particle approximation using an onion-shell model. Particle diffusion within the evolving remnant is explicity taken into account. The particle spectrum becomes steeper with increasing radius as well as SNR age. Simple models of the magnetic field distribution allow a prediction of the intensity and spectrum of radio synchrotron emission and their radial variation. The agreement with existing observations is satisfactory in several SNR's but fails in other cases. Radiative cooling may be an important effect, especially in SNR's exploding in a dense interstellar medium.

  8. Microstructure development in Kolmogorov, Johnson-Mehl, and Avrami nucleation and growth kinetics

    NASA Astrophysics Data System (ADS)

    Pineda, Eloi; Crespo, Daniel

    1999-08-01

    A statistical model with the ability to evaluate the microstructure developed in nucleation and growth kinetics is built in the framework of the Kolmogorov, Johnson-Mehl, and Avrami theory. A populational approach is used to compute the observed grain-size distribution. The impingement process which delays grain growth is analyzed, and the effective growth rate of each population is estimated considering the previous grain history. The proposed model is integrated for a wide range of nucleation and growth protocols, including constant nucleation, pre-existing nuclei, and intermittent nucleation with interface or diffusion-controlled grain growth. The results are compared with Monte Carlo simulations, giving quantitative agreement even in cases where previous models fail.

  9. A Realizable Reynolds Stress Algebraic Equation Model

    NASA Technical Reports Server (NTRS)

    Shih, Tsan-Hsing; Zhu, Jiang; Lumley, John L.

    1993-01-01

    The invariance theory in continuum mechanics is applied to analyze Reynolds stresses in high Reynolds number turbulent flows. The analysis leads to a turbulent constitutive relation that relates the Reynolds stresses to the mean velocity gradients in a more general form in which the classical isotropic eddy viscosity model is just the linear approximation of the general form. On the basis of realizability analysis, a set of model coefficients are obtained which are functions of the time scale ratios of the turbulence to the mean strain rate and the mean rotation rate. The coefficients will ensure the positivity of each component of the mean rotation rate. These coefficients will ensure the positivity of each component of the turbulent kinetic energy - realizability that most existing turbulence models fail to satisfy. Separated flows over backward-facing step configurations are taken as applications. The calculations are performed with a conservative finite-volume method. Grid-independent and numerical diffusion-free solutions are obtained by using differencing schemes of second-order accuracy on sufficiently fine grids. The calculated results are compared in detail with the experimental data for both mean and turbulent quantities. The comparison shows that the present proposal significantly improves the predictive capability of K-epsilon based two equation models. In addition, the proposed model is able to simulate rotational homogeneous shear flows with large rotation rates which all conventional eddy viscosity models fail to simulate.

  10. Why conventional detection methods fail in identifying the existence of contamination events.

    PubMed

    Liu, Shuming; Li, Ruonan; Smith, Kate; Che, Han

    2016-04-15

    Early warning systems are widely used to safeguard water security, but their effectiveness has raised many questions. To understand why conventional detection methods fail to identify contamination events, this study evaluates the performance of three contamination detection methods using data from a real contamination accident and two artificial datasets constructed using a widely applied contamination data construction approach. Results show that the Pearson correlation Euclidean distance (PE) based detection method performs better for real contamination incidents, while the Euclidean distance method (MED) and linear prediction filter (LPF) method are more suitable for detecting sudden spike-like variation. This analysis revealed why the conventional MED and LPF methods failed to identify existence of contamination events. The analysis also revealed that the widely used contamination data construction approach is misleading. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Efficient design of CMOS TSC checkers

    NASA Technical Reports Server (NTRS)

    Biddappa, Anita; Shamanna, Manjunath K.; Maki, Gary; Whitaker, Sterling

    1990-01-01

    This paper considers the design of an efficient, robustly testable, CMOS Totally Self-Checking (TSC) Checker for k-out-of-2k codes. Most existing implementations use primitive gates and assume the single stuck-at fault model. The self-testing property has been found to fail for CMOS TSC checkers under the stuck-open fault model due to timing skews and arbitrary delays in the circuit. A new four level design using CMOS primitive gates (NAND, NOR, INVERTERS) is presented. This design retains its properties under the stuck-open fault model. Additionally, this method offers an impressive reduction (greater than 70 percent) in gate count, gate inputs, and test set size when compared to the existing method. This implementation is easily realizable and is based on Anderson's technique. A thorough comparative study has been made on the proposed implementation and Kundu's implementation and the results indicate that the proposed one is better than Kundu's in all respects for k-out-of-2k codes.

  12. 31 CFR 370.26 - What limitations exist on liability?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... TRANSFERS RELATING TO UNITED STATES SECURITIES Debit Entries § 370.26 What limitations exist on liability? If we sustain a loss because a financial institution fails to handle an entry in accordance with this...

  13. 45 CFR 152.39 - Maintenance of effort.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-EXISTING CONDITION INSURANCE PLAN PROGRAM Relationship to Existing Laws and Programs § 152.39 Maintenance... the contract is entered. (b) Failure to maintain efforts. In situations where a State enters into a..., against any State that fails to maintain funding levels for existing State high risk pools as required...

  14. A New Perspective on Job Lock

    ERIC Educational Resources Information Center

    Huysse-Gaytandjieva, Anna; Groot, Wim; Pavlova, Milena

    2013-01-01

    This paper analyses the situation when employees fail to adapt to overall job dissatisfaction. By combining the existing knowledge in economics on job lock and in psychology on employees' feeling of being "stuck" at work, the paper explains why some employees fail to adapt when dissatisfied with their job. Thus, the paper aims to expand…

  15. The Efficacy of Security Force Assistance in Countering Violent Extremist Organizations in Failed and Potentially Failing States

    DTIC Science & Technology

    2010-06-11

    maintenance funds when the purpose of the training is to enhance interoperability, familiarization , and safety training.3 While technically this type of...funding may not be used for SFA, significant gray area exists when determining what training is interoperability, familiarization , and safety and what

  16. BinQuasi: a peak detection method for ChIP-sequencing data with biological replicates.

    PubMed

    Goren, Emily; Liu, Peng; Wang, Chao; Wang, Chong

    2018-04-19

    ChIP-seq experiments that are aimed at detecting DNA-protein interactions require biological replication to draw inferential conclusions, however there is no current consensus on how to analyze ChIP-seq data with biological replicates. Very few methodologies exist for the joint analysis of replicated ChIP-seq data, with approaches ranging from combining the results of analyzing replicates individually to joint modeling of all replicates. Combining the results of individual replicates analyzed separately can lead to reduced peak classification performance compared to joint modeling. Currently available methods for joint analysis may fail to control the false discovery rate at the nominal level. We propose BinQuasi, a peak caller for replicated ChIP-seq data, that jointly models biological replicates using a generalized linear model framework and employs a one-sided quasi-likelihood ratio test to detect peaks. When applied to simulated data and real datasets, BinQuasi performs favorably compared to existing methods, including better control of false discovery rate than existing joint modeling approaches. BinQuasi offers a flexible approach to joint modeling of replicated ChIP-seq data which is preferable to combining the results of replicates analyzed individually. Source code is freely available for download at https://cran.r-project.org/package=BinQuasi, implemented in R. pliu@iastate.edu or egoren@iastate.edu. Supplementary material is available at Bioinformatics online.

  17. Grade inflation in the internal medicine clerkship: a national survey.

    PubMed

    Fazio, Sara B; Papp, Klara K; Torre, Dario M; Defer, Thomas M

    2013-01-01

    Grade inflation is a growing concern, but the degree to which it continues to exist in 3rd-year internal medicine (IM) clerkships is unknown. The authors sought to determine the degree to which grade inflation is perceived to exist in IM clerkships in North American medical schools. A national survey of all Clerkship Directors in Internal Medicine members was administered in 2009. The authors assessed key aspects of grading. Response rate was 64%. Fifty-five percent of respondents agreed that grade inflation exists in the Internal Medicine clerkship at their school. Seventy-eight percent reported it as a serious/somewhat serious problem, and 38% noted students have passed the IM clerkship at their school who should have failed. A majority of clerkship directors report that grade inflation still exists. In addition, many note students who passed despite the clerkship director believing they should have failed. Interventions should be developed to address both of these problems.

  18. Spatial and temporal variability in rates of landsliding in seismically active mountain ranges

    NASA Astrophysics Data System (ADS)

    Parker, R.; Petley, D.; Rosser, N.; Densmore, A.; Gunasekera, R.; Brain, M.

    2012-04-01

    Where earthquake and precipitation driven disasters occur in steep, mountainous regions, landslides often account for a large proportion of the associated damage and losses. This research addresses spatial and temporal variability in rates of landslide occurrence in seismically active mountain ranges as a step towards developing better regional scale prediction of losses in such events. In the first part of this paper we attempt to explain reductively the variability in spatial rates of landslide occurrence, using data from five major earthquakes. This is achieved by fitting a regression-based conditional probability model to spatial probabilities of landslide occurrence, using as predictor variables proxies for spatial patterns of seismic ground motion and modelled hillslope stability. A combined model for all earthquakes performs well in hindcasting spatial probabilities of landslide occurrence as a function of readily-attainable spatial variables. We present validation of the model and demonstrate the extent to which it may be applied globally to derive landslide probabilities for future earthquakes. In part two we examine the temporal behaviour of rates of landslide occurrence. This is achieved through numerical modelling to simulate the behaviour of a hypothetical landscape. The model landscape is composed of hillslopes that continually weaken, fail and reset in response to temporally-discrete forcing events that represent earthquakes. Hillslopes with different geometries require different amounts of weakening to fail, such that they fail and reset at different temporal rates. Our results suggest that probabilities of landslide occurrence are not temporally constant, but rather vary with time, irrespective of changes in forcing event magnitudes or environmental conditions. Various parameters influencing the magnitude and temporal patterns of this variability are identified, highlighting areas where future research is needed. This model has important implications for landslide hazard and risk analysis in mountain areas as existing techniques usually assume that susceptibility to failure does not change with time.

  19. Applying Social Psychological Models to Predicting HIV-Related Sexual Risk Behaviors Among African Americans

    PubMed Central

    Cochran, Susan D.; Mays, Vickie M.

    2011-01-01

    Existing models of attitude-behavior relationships, including the Health Belief Model, the Theory of Reasoned Action, and the Self-Efficacy Theory, are increasingly being used by psychologists to predict human immunodeficiency virus (HIV)-related risk behaviors. The authors briefly highlight some of the difficulties that might arise in applying these models to predicting the risk behaviors of African Americans. These social psychological models tend to emphasize the importance of individualistic, direct control of behavioral choices and deemphasize factors, such as racism and poverty, particularly relevant to that segment of the African American population most at risk for HIV infection. Applications of these models without taking into account the unique issues associated with behavioral choices within the African American community may fail to capture the relevant determinants of risk behaviors. PMID:23529205

  20. Efficient statistical mapping of avian count data

    USGS Publications Warehouse

    Royle, J. Andrew; Wikle, C.K.

    2005-01-01

    We develop a spatial modeling framework for count data that is efficient to implement in high-dimensional prediction problems. We consider spectral parameterizations for the spatially varying mean of a Poisson model. The spectral parameterization of the spatial process is very computationally efficient, enabling effective estimation and prediction in large problems using Markov chain Monte Carlo techniques. We apply this model to creating avian relative abundance maps from North American Breeding Bird Survey (BBS) data. Variation in the ability of observers to count birds is modeled as spatially independent noise, resulting in over-dispersion relative to the Poisson assumption. This approach represents an improvement over existing approaches used for spatial modeling of BBS data which are either inefficient for continental scale modeling and prediction or fail to accommodate important distributional features of count data thus leading to inaccurate accounting of prediction uncertainty.

  1. CASP10-BCL::Fold efficiently samples topologies of large proteins.

    PubMed

    Heinze, Sten; Putnam, Daniel K; Fischer, Axel W; Kohlmann, Tim; Weiner, Brian E; Meiler, Jens

    2015-03-01

    During CASP10 in summer 2012, we tested BCL::Fold for prediction of free modeling (FM) and template-based modeling (TBM) targets. BCL::Fold assembles the tertiary structure of a protein from predicted secondary structure elements (SSEs) omitting more flexible loop regions early on. This approach enables the sampling of conformational space for larger proteins with more complex topologies. In preparation of CASP11, we analyzed the quality of CASP10 models throughout the prediction pipeline to understand BCL::Fold's ability to sample the native topology, identify native-like models by scoring and/or clustering approaches, and our ability to add loop regions and side chains to initial SSE-only models. The standout observation is that BCL::Fold sampled topologies with a GDT_TS score > 33% for 12 of 18 and with a topology score > 0.8 for 11 of 18 test cases de novo. Despite the sampling success of BCL::Fold, significant challenges still exist in clustering and loop generation stages of the pipeline. The clustering approach employed for model selection often failed to identify the most native-like assembly of SSEs for further refinement and submission. It was also observed that for some β-strand proteins model refinement failed as β-strands were not properly aligned to form hydrogen bonds removing otherwise accurate models from the pool. Further, BCL::Fold samples frequently non-natural topologies that require loop regions to pass through the center of the protein. © 2015 Wiley Periodicals, Inc.

  2. Learning from communities: overcoming difficulties in dissemination of prevention and promotion efforts.

    PubMed

    Miller, Robin L; Shinn, Marybeth

    2005-06-01

    The model of prevention science advocated by the Institute of Medicine (P. J. Mrazek & R. J. Haggerty, 1994) has not lead to widespread adoption of prevention and promotion programs for four reasons. The model of dissemination of programs to communities fails to consider community and organizational capacity to implement programs, ignores the need for congruence in values between programs and host sites, displays a pro-innovation bias that undervalues indigenous practices, and assumes a simplistic model of how community organizations adopt innovations. To address these faults, researchers should locate, study, and help disseminate successful indigenous programs that fit community capacity and values. In addition, they should build on theoretical models of how locally developed programs work to make existing programs and polices more effective.

  3. Bridging the translational gap: collaborative drug development and dispelling the stigma of commercialization.

    PubMed

    Yu, Helen W H

    2016-02-01

    The current drug discovery and development process is stalling the translation of basic science into lifesaving products. Known as the 'Valley of Death', the traditional technology transfer model fails to bridge the gap between early-stage discoveries and preclinical research to advance innovations beyond the discovery phase. In addition, the stigma associated with 'commercialization' detracts from the importance of efficient translation of basic research. Here, I introduce a drug discovery model whereby the respective expertise of academia and industry are brought together to take promising discoveries through to proof of concept as a way to derisk the drug discovery and development process. Known as the 'integrated drug discovery model', I examine here the extent to which existing legal frameworks support this model. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Nutrient mitigation in a temporary river basin.

    PubMed

    Tzoraki, Ourania; Nikolaidis, Nikolaos P; Cooper, David; Kassotaki, Elissavet

    2014-04-01

    We estimate the nutrient budget in a temporary Mediterranean river basin. We use field monitoring and modelling tools to estimate nutrient sources and transfer in both high and low flow conditions. Inverse modelling by the help of PHREEQC model validated the hypothesis of a losing stream during the dry period. Soil and Water Assessment Tool model captured the water quality of the basin. The 'total daily maximum load' approach is used to estimate the nutrient flux status by flow class, indicating that almost 60% of the river network fails to meet nitrogen criteria and 50% phosphate criteria. We recommend that existing well-documented remediation measures such as reforestation of the riparian area or composting of food process biosolids should be implemented to achieve load reduction in close conjunction with social needs.

  5. Molecular mechanism-based model to enhance outcomes of dietary intervention studies for disease prevention

    PubMed Central

    Dey, Moul

    2014-01-01

    Advances in “omics”-based fields have produced an explosion of new information, fueling high expectations for improved public and individualized health. Unfortunately, there exists a widening gap between basic biochemistry and “omics”-based population research, with both disciplines failing to translate their full potential impact to human health applications. A paucity of comprehensive study systems is one of the many roadblocks faced by translational research today. This commentary will highlight the current status of such research, particularly emphasizing the role of nutrigenomics. PMID:25364700

  6. Statistical physics of interacting neural networks

    NASA Astrophysics Data System (ADS)

    Kinzel, Wolfgang; Metzler, Richard; Kanter, Ido

    2001-12-01

    Recent results on the statistical physics of time series generation and prediction are presented. A neural network is trained on quasi-periodic and chaotic sequences and overlaps to the sequence generator as well as the prediction errors are calculated numerically. For each network there exists a sequence for which it completely fails to make predictions. Two interacting networks show a transition to perfect synchronization. A pool of interacting networks shows good coordination in the minority game-a model of competition in a closed market. Finally, as a demonstration, a perceptron predicts bit sequences produced by human beings.

  7. Simulations of Fluvial Landscapes

    NASA Astrophysics Data System (ADS)

    Cattan, D.; Birnir, B.

    2013-12-01

    The Smith-Bretherton-Birnir (SBB) model for fluvial landsurfaces consists of a pair of partial differential equations, one governing water flow and one governing the sediment flow. Numerical solutions of these equations have been shown to provide realistic models in the evolution of fluvial landscapes. Further analysis of these equations shows that they possess scaling laws (Hack's Law) that are known to exist in nature. However, the simulations are highly dependent on the numerical methods used; with implicit methods exhibiting the correct scaling laws, but the explicit methods fail to do so. These equations, and the resulting models, help to bridge the gap between the deterministic and the stochastic theories of landscape evolution. Slight modifications of the SBB equations make the results of the model more realistic. By modifying the sediment flow equation, the model obtains more pronounced meandering rivers. Typical landsurface with rivers.

  8. Applying theories of health behaviour and change to hearing health research: Time for a new approach.

    PubMed

    Coulson, Neil S; Ferguson, Melanie A; Henshaw, Helen; Heffernan, Eithne

    2016-07-01

    In recent years, there has been an increase in the application of behavioural models, such as social cognition models, to the promotion of hearing health. Despite this, there exists a well-developed body of literature that suggests such models may fail to consistently explain reliable amounts of variability in human behaviours. This paper provides a summary of this research across selected models of health-related behaviour, outlining the current state of the evidence. Recent work in the field of behaviour change is presented together with commentary on the design and reporting of behaviour change interventions. We propose that attempts to use unreliable models to explain and predict hearing health behaviours should now be replaced by work which integrates the latest in behaviour change science, such as the Behaviour Change Wheel and Theoretical Domains Framework.

  9. ICT Is Not Participation Is Not Democracy - eParticipation Development Models Revisited

    NASA Astrophysics Data System (ADS)

    Grönlund, Åke

    There exist several models to describe “progress” in eParticipation. Models are typically ladder type and share two assumptions; progress is equalled with more sophisticated use of technology, and direct democracy is seen as the most advanced democracy model. None of the assumptions are true, considering democratic theory, and neither is fruitful as the simplification disturbs analysis and hence obscures actual progress made. The models convey a false impression of progress, but neither the goal, nor the path or the stakeholders driving the development are clearly understood, presented or evidenced. This paper analyses commonly used models based on democratic theory and eParticipation practice, and concludes that all are biased and fail to distinguish between the three dimensions an eParticipation progress model must include; relevance to democracy by any definition, applicability to different processes, (capacity building as well as decision making), and measuring different levels of participation without direct democracy bias.

  10. Human Resource Development in Small Business: An Application of Brethower's Performance Principles to on the Job Training

    ERIC Educational Resources Information Center

    Twyford, Devon; Alagaraja, Meera; Shuck, Brad

    2016-01-01

    Small businesses provide economic infrastructure in which communities develop and thrive and, in the United States alone, currently represent 99.7 percent of all employer firms. However, many small businesses fail to thrive past the first two years of establishment. Of the reasons small businesses fail, limited or non-existent employee training…

  11. The classification of anxiety and hysterical states. Part I. Historical review and empirical delineation.

    PubMed

    Sheehan, D V; Sheehan, K H

    1982-08-01

    The history of the classification of anxiety, hysterical, and hypochondriacal disorders is reviewed. Problems in the ability of current classification schemes to predict, control, and describe the relationship between the symptoms and other phenomena are outlined. Existing classification schemes failed the first test of a good classification model--that of providing categories that are mutually exclusive. The independence of these diagnostic categories from each other does not appear to hold up on empirical testing. In the absence of inherently mutually exclusive categories, further empirical investigation of these classes is obstructed since statistically valid analysis of the nominal data and any useful multivariate analysis would be difficult if not impossible. It is concluded that the existing classifications are unsatisfactory and require some fundamental reconceptualization.

  12. Information-theoretic model comparison unifies saliency metrics

    PubMed Central

    Kümmerer, Matthias; Wallis, Thomas S. A.; Bethge, Matthias

    2015-01-01

    Learning the properties of an image associated with human gaze placement is important both for understanding how biological systems explore the environment and for computer vision applications. There is a large literature on quantitative eye movement models that seeks to predict fixations from images (sometimes termed “saliency” prediction). A major problem known to the field is that existing model comparison metrics give inconsistent results, causing confusion. We argue that the primary reason for these inconsistencies is because different metrics and models use different definitions of what a “saliency map” entails. For example, some metrics expect a model to account for image-independent central fixation bias whereas others will penalize a model that does. Here we bring saliency evaluation into the domain of information by framing fixation prediction models probabilistically and calculating information gain. We jointly optimize the scale, the center bias, and spatial blurring of all models within this framework. Evaluating existing metrics on these rephrased models produces almost perfect agreement in model rankings across the metrics. Model performance is separated from center bias and spatial blurring, avoiding the confounding of these factors in model comparison. We additionally provide a method to show where and how models fail to capture information in the fixations on the pixel level. These methods are readily extended to spatiotemporal models of fixation scanpaths, and we provide a software package to facilitate their use. PMID:26655340

  13. Preliminary Experiments for the Assessment of V/W-band Links for Space-Earth Communications

    NASA Technical Reports Server (NTRS)

    Nessel, James A.; Acosta, Roberto J.; Miranda, Felix A.

    2013-01-01

    Since September 2012, NASA Glenn Research Center has deployed a microwave profiling radiometer at White Sands, NM, to estimate atmospheric propagation effects on communications links in the V and W bands (71-86GHz). Estimates of attenuation statistics in the millimeter wave due to gaseous and cloud components of the atmosphere show good agreement with current ITU-R models, but fail to predict link performance in the presence of moderate to heavy rain rates, due to the inherent limitations of passive radiometry. Herein, we discuss the preliminary results of these measurements and describe a design for a terrestrial link experiment to validate/refine existing rain attenuation models in the V/Wbands.

  14. Preliminary Experiments for the Assessment of VW-Band Links for Space-Earth Communications

    NASA Technical Reports Server (NTRS)

    Nessel, James A.; Acosta, Roberto J.; Miranda, Felix A.

    2013-01-01

    Since September 2012, NASA Glenn Research Center has deployed a microwave profiling radiometer at White Sands, NM, to estimate atmospheric propagation effects on communications links in the V and W bands (71-86GHz). Estimates of attenuation statistics in the millimeter wave due to gaseous and cloud components of the atmosphere show good agreement with current ITU-R models, but fail to predict link performance in the presence of moderate to heavy rain rates, due to the inherent limitations of passive radiometry. Herein, we discuss the preliminary results of these measurements and describe a design for a terrestrial link experiment to validaterefine existing rain attenuation models in the VW-bands.

  15. Measuring and Advancing Experimental Design Ability in an Introductory Course without Altering Existing Lab Curriculum.

    PubMed

    Shanks, Ryan A; Robertson, Chuck L; Haygood, Christian S; Herdliksa, Anna M; Herdliska, Heather R; Lloyd, Steven A

    2017-01-01

    Introductory biology courses provide an important opportunity to prepare students for future courses, yet existing cookbook labs, although important in their own way, fail to provide many of the advantages of semester-long research experiences. Engaging, authentic research experiences aid biology students in meeting many learning goals. Therefore, overlaying a research experience onto the existing lab structure allows faculty to overcome barriers involving curricular change. Here we propose a working model for this overlay design in an introductory biology course and detail a means to conduct this lab with minimal increases in student and faculty workloads. Furthermore, we conducted exploratory factor analysis of the Experimental Design Ability Test (EDAT) and uncovered two latent factors which provide valid means to assess this overlay model's ability to increase advanced experimental design abilities. In a pre-test/post-test design, we demonstrate significant increases in both basic and advanced experimental design abilities in an experimental and comparison group. We measured significantly higher gains in advanced experimental design understanding in students in the experimental group. We believe this overlay model and EDAT factor analysis contribute a novel means to conduct and assess the effectiveness of authentic research experiences in an introductory course without major changes to the course curriculum and with minimal increases in faculty and student workloads.

  16. Recommended test methods and pass/fail criteria for a respirator fit capability test of half-mask air-purifying respirators

    PubMed Central

    Zhuang, Ziqing; Bergman, Michael; Lei, Zhipeng; Niezgoda, George; Shaffer, Ronald

    2017-01-01

    This study assessed key test parameters and pass/fail criteria options for developing a respirator fit capability (RFC) test for half-mask air-purifying particulate respirators. Using a 25-subject test panel, benchmark RFC data were collected for 101 National Institute for Occupational Safety and Health-certified respirator models. These models were further grouped into 61 one-, two-, or three-size families. Fit testing was done using a PortaCount® Plus with N95-Companion accessory and an Occupational Safety and Health Administration-accepted quantitative fit test protocol. Three repeated tests (donnings) per subject/respirator model combination were performed. The panel passing rate (PPR) (number or percentage of the 25-subject panel achieving acceptable fit) was determined for each model using five different alternative criteria for determining acceptable fit. When the 101 models are evaluated individually (i.e., not grouped by families), the percentages of models capable of fitting >75% (19/25 subjects) of the panel were 29% and 32% for subjects achieving a fit factor ≥100 for at least one of the first two donnings and at least one of three donnings, respectively. When the models are evaluated grouped into families and using >75% of panel subjects achieving a fit factor ≥100 for at least one of two donnings as the PPR pass/fail criterion, 48% of all models can pass. When >50% (13/25 subjects) of panel subjects was the PPR criterion, the percentage of passing models increased to 70%. Testing respirators grouped into families and evaluating the first two donnings for each of two respirator sizes provided the best balance between meeting end user expectations and creating a performance bar for manufacturers. Specifying the test criterion for a subject obtaining acceptable fit as achieving a fit factor ≥100 on at least one out of the two donnings is reasonable because a majority of existing respirator families can achieve an PPR of >50% using this criterion. The different test criteria can be considered by standards development organizations when developing standards. PMID:28278067

  17. Recommended test methods and pass/fail criteria for a respirator fit capability test of half-mask air-purifying respirators.

    PubMed

    Zhuang, Ziqing; Bergman, Michael; Lei, Zhipeng; Niezgoda, George; Shaffer, Ronald

    2017-06-01

    This study assessed key test parameters and pass/fail criteria options for developing a respirator fit capability (RFC) test for half-mask air-purifying particulate respirators. Using a 25-subject test panel, benchmark RFC data were collected for 101 National Institute for Occupational Safety and Health-certified respirator models. These models were further grouped into 61 one-, two-, or three-size families. Fit testing was done using a PortaCount® Plus with N95-Companion accessory and an Occupational Safety and Health Administration-accepted quantitative fit test protocol. Three repeated tests (donnings) per subject/respirator model combination were performed. The panel passing rate (PPR) (number or percentage of the 25-subject panel achieving acceptable fit) was determined for each model using five different alternative criteria for determining acceptable fit. When the 101 models are evaluated individually (i.e., not grouped by families), the percentages of models capable of fitting >75% (19/25 subjects) of the panel were 29% and 32% for subjects achieving a fit factor ≥100 for at least one of the first two donnings and at least one of three donnings, respectively. When the models are evaluated grouped into families and using >75% of panel subjects achieving a fit factor ≥100 for at least one of two donnings as the PPR pass/fail criterion, 48% of all models can pass. When >50% (13/25 subjects) of panel subjects was the PPR criterion, the percentage of passing models increased to 70%. Testing respirators grouped into families and evaluating the first two donnings for each of two respirator sizes provided the best balance between meeting end user expectations and creating a performance bar for manufacturers. Specifying the test criterion for a subject obtaining acceptable fit as achieving a fit factor ≥100 on at least one out of the two donnings is reasonable because a majority of existing respirator families can achieve an PPR of >50% using this criterion. The different test criteria can be considered by standards development organizations when developing standards.

  18. You can't always get what you want: infants understand failed goal-directed actions.

    PubMed

    Brandone, Amanda C; Wellman, Henry M

    2009-01-01

    At what age do infants understand that goals exist independently of the actions that result from them? Exploring infants' understanding of failed intentional actions-when the goal of the action is unfulfilled and thus not apparent in the actor's movements-is a critical step in answering this question. Using a visual habituation paradigm, we assessed when infants understand that a failed intentional action is goal directed and whether an understanding of successful intentional actions (actions that do overtly attain their goals) precedes an understanding of failed intentional actions. Results demonstrated that 10- and 12-month-olds recognized the goal directedness of both successful and failed reaching actions. Eight-month-olds also recognized the goal directedness of successful actions, but not of unsuccessful attempts. Thus, by the end of the 1st year of life, infants possess an impressive understanding of intentional action, and an understanding of failed intentional actions follows an earlier understanding of successful ones.

  19. Above-knee prosthesis design based on fatigue life using finite element method and design of experiment.

    PubMed

    Phanphet, Suwattanarwong; Dechjarern, Surangsee; Jomjanyong, Sermkiat

    2017-05-01

    The main objective of this work is to improve the standard of the existing design of knee prosthesis developed by Thailand's Prostheses Foundation of Her Royal Highness The Princess Mother. The experimental structural tests, based on the ISO 10328, of the existing design showed that a few components failed due to fatigue under normal cyclic loading below the required number of cycles. The finite element (FE) simulations of structural tests on the knee prosthesis were carried out. Fatigue life predictions of knee component materials were modeled based on the Morrow's approach. The fatigue life prediction based on the FE model result was validated with the corresponding structural test and the results agreed well. The new designs of the failed components were studied using the design of experimental approach and finite element analysis of the ISO 10328 structural test of knee prostheses under two separated loading cases. Under ultimate loading, knee prosthesis peak von Mises stress must be less than the yield strength of knee component's material and the total knee deflection must be lower than 2.5mm. The fatigue life prediction of all knee components must be higher than 3,000,000 cycles under normal cyclic loading. The design parameters are the thickness of joint bars, the diameter of lower connector and the thickness of absorber-stopper. The optimized knee prosthesis design meeting all the requirements was recommended. Experimental ISO 10328 structural test of the fabricated knee prosthesis based on the optimized design confirmed the finite element prediction. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  20. FEDAL SYSTEM OPERATION DURING STATION START-UP. Test Results (T-643734). Core I, Seed 2. Section I

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

    None

    An investigation was conducted to determine if any failed blanket fuel elements exist in core locations previously found to have high levels of delayed neutron emitter activity. Data from Fedal System monitors indicate that J5 may have a failed blanket element, there is no evidence of failure at core location F7. (J.R.D.)

  1. Sociolinguistically Informed Natural Language Processing: Automating Irony Detection

    DTIC Science & Technology

    2017-10-23

    ML and NLP technologies fail to detect ironic intent empirically. We specifically proposed to assess quantitatively (using the collected dataset...Aim 2. To analyze when existing ML and NLP technologies fail to detect ironic intent empirically. We specifically proposed to assess quantitatively ...of the embedding reddit thread, and the other comments in this thread) constitute 4 sub-reddit (URL) description number of labeled comments politics

  2. Identification Approach to Alleviate Effects of Unmeasured Heat Gains for MIMO Building Thermal Systems

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

    Cai, Jie; Kim, Donghun; Braun, James E.

    It is important to have practical methods for constructing a good mathematical model for a building's thermal system for energy audits, retrofit analysis and advanced building controls, e.g. model predictive control. Identification approaches based on semi-physical model structures are popular in building science for those purposes. However conventional gray box identification approaches applied to thermal networks would fail when significant unmeasured heat gains present in estimation data. Although this situation is very common and practical, there has been little research to tackle this issue in building science. This paper presents an overall identification approach to alleviate influences of unmeasured disturbances,more » and hence to obtain improved gray-box building models. The approach was applied to an existing open space building and the performance is demonstrated.« less

  3. Examining Belief and Confidence in Schizophrenia

    PubMed Central

    Joyce, Dan W.; Averbeck, Bruno B.; Frith, Chris D.; Shergill, Sukhwinder S.

    2018-01-01

    Background People with psychoses often report fixed, delusional beliefs that are sustained even in the presence of unequivocal contrary evidence. Such delusional beliefs are the result of integrating new and old evidence inappropriately in forming a cognitive model. We propose and test a cognitive model of belief formation using experimental data from an interactive “Rock Paper Scissors” game. Methods Participants (33 controls and 27 people with schizophrenia) played a competitive, time-pressured interactive two-player game (Rock, Paper, Scissors). Participant’s behavior was modeled by a generative computational model using leaky-integrator and temporal difference methods. This model describes how new and old evidence is integrated to form both a playing strategy to beat the opponent and provide a mechanism for reporting confidence in one’s playing strategy to win against the opponent Results People with schizophrenia fail to appropriately model their opponent’s play despite consistent (rather than random) patterns that can be exploited in the simulated opponent’s play. This is manifest as a failure to weigh existing evidence appropriately against new evidence. Further, participants with schizophrenia show a ‘jumping to conclusions’ bias, reporting successful discovery of a winning strategy with insufficient evidence. Conclusions The model presented suggests two tentative mechanisms in delusional belief formation – i) one for modeling patterns in other’s behavior, where people with schizophrenia fail to use old evidence appropriately and ii) a meta-cognitive mechanism for ‘confidence’ in such beliefs where people with schizophrenia overweight recent reward history in deciding on the value of beliefs about the opponent. PMID:23521846

  4. Work-Related Injury Surveillance in Vietnam: A National Reporting System Model

    PubMed Central

    Marucci-Wellman, Helen; Wegman, David H.; Leamon, Tom B.; Tuyet Binh, Ta Thi; Diep, Nguyen Bich; Kriebel, David

    2013-01-01

    Developing nations bear a substantial portion of the global burden of injury. Public health surveillance models in developing countries should recognize injury risks for all levels of society and all causes and should incorporate various groups of workers and industries, including subsistence agriculture. However, many developing nations do not have an injury registration system; current data collection methods result in gross national undercounts of injuries, failing to distinguish injuries that occur during work. In 2006, we established an active surveillance system in Vietnam’s Xuan Tien commune and investigated potential methods for surveillance of work-related injuries. On the basis of our findings, we recommend a national model for work-related injury surveillance in Vietnam that builds on the existing health surveillance system. PMID:24028255

  5. Failed rib region prediction in a human body model during crash events with precrash braking.

    PubMed

    Guleyupoglu, B; Koya, B; Barnard, R; Gayzik, F S

    2018-02-28

    The objective of this study is 2-fold. We used a validated human body finite element model to study the predicted chest injury (focusing on rib fracture as a function of element strain) based on varying levels of simulated precrash braking. Furthermore, we compare deterministic and probabilistic methods of rib injury prediction in the computational model. The Global Human Body Models Consortium (GHBMC) M50-O model was gravity settled in the driver position of a generic interior equipped with an advanced 3-point belt and airbag. Twelve cases were investigated with permutations for failure, precrash braking system, and crash severity. The severities used were median (17 kph), severe (34 kph), and New Car Assessment Program (NCAP; 56.4 kph). Cases with failure enabled removed rib cortical bone elements once 1.8% effective plastic strain was exceeded. Alternatively, a probabilistic framework found in the literature was used to predict rib failure. Both the probabilistic and deterministic methods take into consideration location (anterior, lateral, and posterior). The deterministic method is based on a rubric that defines failed rib regions dependent on a threshold for contiguous failed elements. The probabilistic method depends on age-based strain and failure functions. Kinematics between both methods were similar (peak max deviation: ΔX head = 17 mm; ΔZ head = 4 mm; ΔX thorax = 5 mm; ΔZ thorax = 1 mm). Seat belt forces at the time of probabilistic failed region initiation were lower than those at deterministic failed region initiation. The probabilistic method for rib fracture predicted more failed regions in the rib (an analog for fracture) than the deterministic method in all but 1 case where they were equal. The failed region patterns between models are similar; however, there are differences that arise due to stress reduced from element elimination that cause probabilistic failed regions to continue to rise after no deterministic failed region would be predicted. Both the probabilistic and deterministic methods indicate similar trends with regards to the effect of precrash braking; however, there are tradeoffs. The deterministic failed region method is more spatially sensitive to failure and is more sensitive to belt loads. The probabilistic failed region method allows for increased capability in postprocessing with respect to age. The probabilistic failed region method predicted more failed regions than the deterministic failed region method due to force distribution differences.

  6. Modeling the interdependent network based on two-mode networks

    NASA Astrophysics Data System (ADS)

    An, Feng; Gao, Xiangyun; Guan, Jianhe; Huang, Shupei; Liu, Qian

    2017-10-01

    Among heterogeneous networks, there exist obviously and closely interdependent linkages. Unlike existing research primarily focus on the theoretical research of physical interdependent network model. We propose a two-layer interdependent network model based on two-mode networks to explore the interdependent features in the reality. Specifically, we construct a two-layer interdependent loan network and develop several dependent features indices. The model is verified to enable us to capture the loan dependent features of listed companies based on loan behaviors and shared shareholders. Taking Chinese debit and credit market as case study, the main conclusions are: (1) only few listed companies shoulder the main capital transmission (20% listed companies occupy almost 70% dependent degree). (2) The control of these key listed companies will be more effective of avoiding the spreading of financial risks. (3) Identifying the companies with high betweenness centrality and controlling them could be helpful to monitor the financial risk spreading. (4) The capital transmission channel among Chinese financial listed companies and Chinese non-financial listed companies are relatively strong. However, under greater pressure of demand of capital transmission (70% edges failed), the transmission channel, which constructed by debit and credit behavior, will eventually collapse.

  7. Commons ignorance: the failure of environmental law to produce needed information on health and the environment.

    PubMed

    Wagner, Wendy E

    2004-04-01

    One of the most significant problems facing environmental law is the dearth of scientific information available to assess the impact of industrial activities on public health and the environment. After documenting the significant gaps in existing information, this Article argues that existing laws both exacerbate and perpetuate this problem. By failing to require actors to assess the potential harm from their activities, and by penalizing them with additional regulation when they do, existing laws fail to counteract actors' natural inclination to remain silent about the harms that they might be causing. Both theory and practice confirm that when the stakes are high, actors not only will resist producing potentially incriminating information but will invest in discrediting public research that suggests their activities are harmful. The Article concludes with specific recommendations about how these perverse incentives for ignorance can be reversed.

  8. Milgrom's revision of Newton's laws - Dynamical and cosmological consequences

    NASA Technical Reports Server (NTRS)

    Felten, J. E.

    1984-01-01

    Milgrom's (1983) recent revision of Newtonian dynamics was introduced to eliminate the inference that large quantities of invisible mass exist in galaxies. It is shown by simple examples that a Milgrom acceleration, in the form presented so far, implies other far-reaching changes in dynamics. The momentum of an isolated system is not conserved, and the usual theorem for center-of-mass motion of any system does not hold. Naive applications require extreme caution. The model fails to provide a complete description of particle dynamics and should be thought of as a revision of Kepler's laws rather than Newton's. The Milgrom acceleration also implies fundamental changes in cosmology. A quasi-Newtonian calculation adapted from Newtonian cosmology suggests that a 'Milgrom universe' will recollapse even if the classical closure parameter Omega is much less than unity. The solution, however, fails to satisfy the cosmological principle. Reasons for the breakdown of this calculation are examined. A new theory of gravitation will be needed before the behavior of a Milgrom universe can be predicted.

  9. Milgrom's revision of cosmic dynamics: Amending Newton's laws or Keplers?

    NASA Technical Reports Server (NTRS)

    Felten, J. E.

    1983-01-01

    Milgrom's recent revision of Newtonian dynamics was introduced to eliminate the inference that large quantities of invisible mass exist in galaxies. Simple examples show that a Milgrom acceleration, in the form presented so far, imply other far-reaching changes in dynamics. The momentum of an isolated system is not conserved, and the usual theorem for center-of-mass motion of any system does not hold. Naive applications require extreme caution. The model fails to provide a complete description of particle dynamics and should be thought of as a revision of Kepler's laws rather than Newton's. The Milgrom acceleration also implies fundamental changes in cosmology. A quasi-Newtonian calculation adapted from Newtonian cosmology suggests that a Milgrom universe will recollapse even if the classical closure parameter theta is less than 1. The solution, however, fails to satisfy the cosmological principle. Reasons for the breakdown of this calculation are examined. A theory of gravitation needed before the behavior of a Milgrom universe can be predicted.

  10. Inward Leakage Variability between Respirator Fit Test Panels – Part I. Deterministic Approach

    PubMed Central

    Zhuang, Ziqing; Liu, Yuewei; Coffey, Christopher C.; Miller, Colleen; Szalajda, Jonathan

    2015-01-01

    Inter-panel variability has never been investigated. The objective of this study was to determine the variability between different anthropometric panels used to determine the inward leakage (IL) of N95 filtering facepiece respirators (FFRs) and elastomeric half-mask respirators (EHRs). A total of 144 subjects, who were both experienced and non-experienced N95 FFR users, were recruited. Five N95 FFRs and five N95 EHRs were randomly selected from among those models tested previously in our laboratory. The PortaCount Pro+ (without N95-Companion) was used to measure IL of the ambient particles with a detectable size range of 0.02 to 1 μm. The Occupational Safety and Health Administration standard fit test exercises were used for this study. IL test were performed for each subject using each of the 10 respirators. Each respirator/subject combination was tested in duplicate, resulting in a total 20 IL tests for each subject. Three 35-member panels were randomly selected without replacement from the 144 study subjects stratified by the National Institute for Occupational Safety and Health bivariate panel cell for conducting statistical analyses. The geometric mean (GM) IL values for all 10 studied respirators were not significantly different among the three randomly selected 35-member panels. Passing rate was not significantly different among the three panels for all respirators combined or by each model. This was true for all IL pass/fail levels of 1%, 2%, and 5%. Using 26 or more subjects to pass the IL test, all three panels had consistent passing/failing results for pass/fail levels of 1% and 5%. Some disagreement was observed for the 2% pass/fail level. Inter-panel variability exists, but it is small relative to the other sources of variation in fit testing data. The concern about inter-panel variability and other types of variability can be alleviated by properly selecting: pass/fail level (IL 1–5%); panel size (e.g., 25 or 35); and minimum number of subjects required to pass (e.g., 26 of 35 or 23 of 35). PMID:26011282

  11. 22 CFR 34.18 - Waivers of indebtedness.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... there exists in connection with the claim an indication of fraud, misrepresentation, fault, or lack of... known through the exercise of due diligence that an error existed but failed to take corrective action... payment. (iv) If the deciding official finds no indication of fraud, misrepresentation, fault, or lack of...

  12. Performance of Smagorinsky and dynamic models in near surface turbulence

    NASA Astrophysics Data System (ADS)

    Brasseur, James G.; Juneja, Anurag

    1997-11-01

    In LES of high-Reynolds-number wall bounded turbulence such as the atmospheric boundary layer (ABL), a viscous sublayer either does not exist or is within the first grid cell, and some integral scale motions are necessarily under-resolved at the first few grid locations. Here the subgrid terms dominate the evolution of resolved velocity and the SGS model performance becomes crucial. To develop improved closures for surface layer turbulence (under-resolved and anisotropic), we explore (a) why current SGS closures fail and (b) what needs to be fixed. We evaluate the performance of the Smagorinsky and dynamic models using DNS data from shear- and buoyancy-driven turbulence as a function of filter cutoff location. We find that the underlying assumption of good alignment between the subgrid stress and resolved strain-rate tensors is not correct in general. More importantly, the Smagorinsky model incorrectly predicts a strong preference in the direction of the SGS stress divergence vector, a spurious prediction that is directly related to the anisotropic structure of the resolved turbulence field. This, and its under-estimation of the SGS pressure gradient, are likely sources of the errors observed in LES of the ABL. Whereas the dynamic formulations do a better job predicting some SGS dynamics, the model fails when the filter cutoff is near an integral scale, and predicts unreasonable fluctuation levels-- although performance is sensitive to type of averaging. *supported by ARO grant DAAL03-92-0117.

  13. Central Appalachia in advanced capitalism: its coal industry structure and coal operator associations

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

    Walls, D.S.

    1978-01-01

    This study traces the origins of the notion that Appalachia constitutes a unique social-problem region, examines the models of Appalachian problems popularized during the 1960s, proposes an alternative framework for situating the Central Appalachian coalfields, and examines aspects of the coal industry's structure in the Central Appalachian region. The idea of Appalachia as a distinctive social problem region was created between 1890 and 1930 by a social movement affiliated with various Protestant church home mission boards and organizationally focused in the Conference of Southern Mountain Workers and Berea College. The movement stressed an environmental explanation of regional problems. During themore » 1960s, three explanatory models of Appalachian poverty and underdevelopment achieved prominence: the subculture of poverty model, the regional development model, and the internal colonialism model. Each contributed to a regionalized conception of Appalachian problems. Empirical studies show the subculture of poverty model to fail as an explanation of regional underdevelopment. In the absence of a critique of domination and a redistribution of power and wealth, the regional development model serves as a rationalization of existing structures of privilege. The internal colonialism model provides a critique of domination, but not the most appropriate one. This study argues that the above models should not be viewed as mutually exclusive formulations, and that they may be reconstructed to represent different dimensions of social existence.« less

  14. Modeling mania in preclinical settings: a comprehensive review

    PubMed Central

    Sharma, Ajaykumar N.; Fries, Gabriel R.; Galvez, Juan F.; Valvassori, Samira S.; Soares, Jair C.; Carvalho, André F.; Quevedo, Joao

    2015-01-01

    The current pathophysiological understanding of mechanisms leading to onset and progression of bipolar manic episodes remains limited. At the same time, available animal models for mania have limited face, construct, and predictive validities. Additionally, these models fail to encompass recent pathophysiological frameworks of bipolar disorder (BD), e.g. neuroprogression. Therefore, there is a need to search for novel preclinical models for mania that could comprehensively address these limitations. Herein we review the history, validity, and caveats of currently available animal models for mania. We also review new genetic models for mania, namely knockout mice for genes involved in neurotransmission, synapse formation, and intracellular signaling pathways. Furthermore, we review recent trends in preclinical models for mania that may aid in the comprehension of mechanisms underlying the neuroprogressive and recurring nature of BD. In conclusion, the validity of animal models for mania remains limited. Nevertheless, novel (e.g. genetic) animal models as well as adaptation of existing paradigms hold promise. PMID:26545487

  15. PyLDTk: Python toolkit for calculating stellar limb darkening profiles and model-specific coefficients for arbitrary filters

    NASA Astrophysics Data System (ADS)

    Parviainen, Hannu

    2015-10-01

    PyLDTk automates the calculation of custom stellar limb darkening (LD) profiles and model-specific limb darkening coefficients (LDC) using the library of PHOENIX-generated specific intensity spectra by Husser et al. (2013). It facilitates exoplanet transit light curve modeling, especially transmission spectroscopy where the modeling is carried out for custom narrow passbands. PyLDTk construct model-specific priors on the limb darkening coefficients prior to the transit light curve modeling. It can also be directly integrated into the log posterior computation of any pre-existing transit modeling code with minimal modifications to constrain the LD model parameter space directly by the LD profile, allowing for the marginalization over the whole parameter space that can explain the profile without the need to approximate this constraint by a prior distribution. This is useful when using a high-order limb darkening model where the coefficients are often correlated, and the priors estimated from the tabulated values usually fail to include these correlations.

  16. Modelling operations and security of cloud systems using Z-notation and Chinese Wall security policy

    NASA Astrophysics Data System (ADS)

    Basu, Srijita; Sengupta, Anirban; Mazumdar, Chandan

    2016-11-01

    Enterprises are increasingly using cloud computing for hosting their applications. Availability of fast Internet and cheap bandwidth are causing greater number of people to use cloud-based services. This has the advantage of lower cost and minimum maintenance. However, ensuring security of user data and proper management of cloud infrastructure remain major areas of concern. Existing techniques are either too complex, or fail to properly represent the actual cloud scenario. This article presents a formal cloud model using the constructs of Z-notation. Principles of the Chinese Wall security policy have been applied to design secure cloud-specific operations. The proposed methodology will enable users to safely host their services, as well as process sensitive data, on cloud.

  17. Neural Network Model for Thermal Inactivation of Salmonella Typhimurium to Elimination in Ground Chicken: Acquisition of Data by Whole Sample Enrichment, Miniature Most-Probable-Number Method.

    PubMed

    Oscar, T P

    2017-01-01

    Predictive models are valuable tools for assessing food safety. Existing thermal inactivation models for Salmonella and ground chicken do not provide predictions above 71°C, which is below the recommended final cooked temperature of 73.9°C for chicken. They also do not predict when all Salmonella are eliminated without extrapolating beyond the data used to develop them. Thus, a study was undertaken to develop a model for thermal inactivation of Salmonella to elimination in ground chicken at temperatures above those of existing models. Ground chicken thigh portions (0.76 cm 3 ) in microcentrifuge tubes were inoculated with 4.45 ± 0.25 log most probable number (MPN) of a single strain of Salmonella Typhimurium (chicken isolate). They were cooked at 50 to 100°C in 2 or 2.5°C increments in a heating block that simulated two-sided pan frying. A whole sample enrichment, miniature MPN (WSE-mMPN) method was used for enumeration. The lower limit of detection was one Salmonella cell per portion. MPN data were used to develop a multiple-layer feedforward neural network model. Model performance was evaluated using the acceptable prediction zone (APZ) method. The proportion of residuals in an APZ (pAPZ) from -1 log (fail-safe) to 0.5 log (fail-dangerous) was 0.911 (379 of 416) for dependent data and 0.910 (162 of 178) for independent data for interpolation. A pAPZ ≥0.7 indicated that model predictions had acceptable bias and accuracy. There were no local prediction problems because pAPZ for individual thermal inactivation curves ranged from 0.813 to 1.000. Independent data for interpolation satisfied the test data criteria of the APZ method. Thus, the model was successfully validated. Predicted times for a 1-log reduction ranged from 9.6 min at 56°C to 0.71 min at 100°C. Predicted times for elimination ranged from 8.6 min at 60°C to 1.4 min at 100°C. The model will be a valuable new tool for predicting and managing this important risk to public health.

  18. A Solution to ``Too Big to Fail''

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-10-01

    Its a tricky business to reconcile simulations of our galaxys formation with our current observations of the Milky Way and its satellites. In a recent study, scientists have addressed one discrepancy between simulations and observations: the so-called to big to fail problem.From Missing Satellites to Too Big to FailThe favored model of the universe is the lambda-cold-dark-matter (CDM) cosmological model. This model does a great job of correctly predicting the large-scale structure of the universe, but there are still a few problems with it on smaller scales.Hubble image of UGC 5497, a dwarf galaxy associated with Messier 81. In the missing satellite problem, simulations of galaxy formation predict that there should be more such satellite galaxies than we observe. [ESA/NASA]The first is the missing satellites problem: CDM cosmology predicts that galaxies like the Milky Way should have significantly more satellite galaxies than we observe. A proposed solution to this problem is the argument that there may exist many more satellites than weve observed, but these dwarf galaxies have had their stars stripped from them during tidal interactions which prevents us from being able to see them.This solution creates a new problem, though: the too big to fail problem. This problem states that many of the satellites predicted by CDM cosmology are simply so massive that theres no way they couldnt have visible stars. Another way of looking at it: the observed satellites of the Milky Way are not massive enough to be consistent with predictions from CDM.Artists illustration of a supernova, a type of stellar feedback that can modify the dark-matter distribution of a satellite galaxy. [NASA/CXC/M. Weiss]Density Profiles and Tidal StirringLed by Mihai Tomozeiu (University of Zurich), a team of scientists has published a study in which they propose a solution to the too big to fail problem. By running detailed cosmological zoom simulations of our galaxys formation, Tomozeiu and collaborators modeled the dark matter and the stellar content of the galaxy, tracking the formation and evolution of dark-matter subhalos.Based on the results of their simulations, the team argues that the too big to fail problem can be resolved by combining two effects:Stellar feedback in a satellite galaxy can modify its dark-matter distribution, lowering the dark-matter density in the galaxys center and creating a shallower density profile. Satellites with such shallow density profiles evolve differently than those typically modeled, which have a high concentration of dark matter in their centers.After these satellites fall into the Milky Ways potential, tidal effects such as shocks and stripping modify the mass distribution of both the dark matter and the baryons even further.Each curve represents a simulated satellites circular velocity (which corresponds to its total mass) at z=0. Left: results using typical dark-matter density profiles. Right: results using the shallower profiles expected when stellar feedback is included. Results from the shallower profiles are consistent with observed Milky-Way satellites(black crosses). [Adapted from Tomozeiu et al. 2016]A Match to ObservationsTomozeiu and collaborators found that when they used traditional density profiles to model the satellites, the satellites at z=0 in the simulation were much larger than those we observe around the Milky Way consistent with the too big to fail problem.When the team used shallower density profiles and took into account tidal effects, however, the simulations produced a distribution of satellites at z=0 that is consistent with what we observe.This study provides a tidy potential solution to the too big to fail problem, further strengthening the support for CDM cosmology.CitationMihai Tomozeiu et al 2016 ApJ 827 L15. doi:10.3847/2041-8205/827/1/L15

  19. Modelling the light-scattering properties of a planetary-regolith analog sample

    NASA Astrophysics Data System (ADS)

    Vaisanen, T.; Markkanen, J.; Hadamcik, E.; Levasseur-Regourd, A. C.; Lasue, J.; Blum, J.; Penttila, A.; Muinonen, K.

    2017-12-01

    Solving the scattering properties of asteroid surfaces can be made cheaper, faster, and more accurate with reliable physics-based electromagnetic scattering programs for large and dense random media. Existing exact methods fail to produce solutions for such large systems and it is essential to develop approximate methods. Radiative transfer (RT) is an approximate method which works for sparse random media such as atmospheres fails when applied to dense media. In order to make the method applicable to dense media, we have developed a radiative-transfer coherent-backscattering method (RT-CB) with incoherent interactions. To show the current progress with the RT-CB, we have modeled a planetary-regolith analog sample. The analog sample is a low-density agglomerate produced by random ballistic deposition of almost equisized silicate spheres studied using the PROGRA2-surf experiment. The scattering properties were then computed with the RT-CB assuming that the silicate spheres were equisized and that there were a Gaussian particle size distribution. The results were then compared to the measured data and the intensity plot is shown below. The phase functions are normalized to unity at the 40-deg phase angle. The tentative intensity modeling shows good match with the measured data, whereas the polarization modeling shows discrepancies. In summary, the current RT-CB modeling is promising, but more work needs to be carried out, in particular, for modeling the polarization. Acknowledgments. Research supported by European Research Council with Advanced Grant No. 320773 SAEMPL, Scattering and Absorption of ElectroMagnetic waves in ParticuLate media. Computational resources provided by CSC - IT Centre for Science Ltd, Finland.

  20. A critique of the cross-lagged panel model.

    PubMed

    Hamaker, Ellen L; Kuiper, Rebecca M; Grasman, Raoul P P P

    2015-03-01

    The cross-lagged panel model (CLPM) is believed by many to overcome the problems associated with the use of cross-lagged correlations as a way to study causal influences in longitudinal panel data. The current article, however, shows that if stability of constructs is to some extent of a trait-like, time-invariant nature, the autoregressive relationships of the CLPM fail to adequately account for this. As a result, the lagged parameters that are obtained with the CLPM do not represent the actual within-person relationships over time, and this may lead to erroneous conclusions regarding the presence, predominance, and sign of causal influences. In this article we present an alternative model that separates the within-person process from stable between-person differences through the inclusion of random intercepts, and we discuss how this model is related to existing structural equation models that include cross-lagged relationships. We derive the analytical relationship between the cross-lagged parameters from the CLPM and the alternative model, and use simulations to demonstrate the spurious results that may arise when using the CLPM to analyze data that include stable, trait-like individual differences. We also present a modeling strategy to avoid this pitfall and illustrate this using an empirical data set. The implications for both existing and future cross-lagged panel research are discussed. (c) 2015 APA, all rights reserved).

  1. Recovery of failed solid-state anaerobic digesters.

    PubMed

    Yang, Liangcheng; Ge, Xumeng; Li, Yebo

    2016-08-01

    This study examined the performance of three methods for recovering failed solid-state anaerobic digesters. The 9-L digesters, which were fed with corn stover, failed at a feedstock/inoculum (F/I) ratio of 10 with negligible methane yields. To recover the systems, inoculum was added to bring the F/I ratio to 4. Inoculum was either added to the top of a failed digester, injected into it, or well-mixed with the existing feedstock. Digesters using top-addition and injection methods quickly resumed and achieved peak yields in 10days, while digesters using well-mixed method recovered slowly but showed 50% higher peak yields. Overall, these methods recovered 30-40% methane from failed digesters. The well-mixed method showed the highest methane yield, followed by the injection and top-addition methods. Recovered digesters outperformed digesters had a constant F/I ratio of 4. Slow mass transfer and slow growth of microbes were believed to be the major limiting factors for recovery. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Representation of the West African Monsoon System in the aerosol-climate model ECHAM6-HAM2

    NASA Astrophysics Data System (ADS)

    Stanelle, Tanja; Lohmann, Ulrike; Bey, Isabelle

    2017-04-01

    The West African Monsoon (WAM) is a major component of the global monsoon system. The temperature contrast between the Saharan land surface in the North and the sea surface temperature in the South dominates the WAM formation. The West African region receives most of its precipitation during the monsoon season between end of June and September. Therefore the existence of the monsoon is of major social and economic importance. We discuss the ability of the climate model ECHAM6 as well as the coupled aerosol climate model ECHAM6-HAM2 to simulate the major features of the WAM system. The north-south temperature gradient is reproduced by both model versions but all model versions fail in reproducing the precipitation amount south of 10° N. A special focus is on the representation of the nocturnal low level jet (NLLJ) and the corresponding enhancement of low level clouds (LLC) at the Guinea Coast, which are a crucial factor for the regional energy budget. Most global climate models have difficulties to represent these features. The pure climate model ECHAM6 is able to simulate the existence of the NLLJ and LLC, but the model does not represent the pronounced diurnal cycle. Overall, the representation of LLC is worse in the coupled model. We discuss the model behaviors on the basis of outputted temperature and humidity tendencies and try to identify potential processes responsible for the model deficiencies.

  3. Evaluating remedial alternatives for an acid mine drainage stream: A model post audit

    USGS Publications Warehouse

    Runkel, Robert L.; Kimball, Briant A.; Walton-Day, Katherine; Verplanck, Philip L.; Broshears, Robert E.

    2012-01-01

    A post audit for a reactive transport model used to evaluate acid mine drainage treatment systems is presented herein. The post audit is based on a paired synoptic approach in which hydrogeochemical data are collected at low (existing conditions) and elevated (following treatment) pH. Data obtained under existing, low-pH conditions are used for calibration, and the resultant model is used to predict metal concentrations observed following treatment. Predictions for Al, As, Fe, H+, and Pb accurately reproduce the observed reduction in dissolved concentrations afforded by the treatment system, and the information provided in regard to standard attainment is also accurate (predictions correctly indicate attainment or nonattainment of water quality standards for 19 of 25 cases). Errors associated with Cd, Cu, and Zn are attributed to misspecification of sorbent mass (precipitated Fe). In addition to these specific results, the post audit provides insight in regard to calibration and sensitivity analysis that is contrary to conventional wisdom. Steps taken during the calibration process to improve simulations of As sorption were ultimately detrimental to the predictive results, for example, and the sensitivity analysis failed to bracket observed metal concentrations.

  4. A new theory of plant-microbe nutrient competition resolves inconsistencies between observations and model predictions.

    PubMed

    Zhu, Qing; Riley, William J; Tang, Jinyun

    2017-04-01

    Terrestrial plants assimilate anthropogenic CO 2 through photosynthesis and synthesizing new tissues. However, sustaining these processes requires plants to compete with microbes for soil nutrients, which therefore calls for an appropriate understanding and modeling of nutrient competition mechanisms in Earth System Models (ESMs). Here, we survey existing plant-microbe competition theories and their implementations in ESMs. We found no consensus regarding the representation of nutrient competition and that observational and theoretical support for current implementations are weak. To reconcile this situation, we applied the Equilibrium Chemistry Approximation (ECA) theory to plant-microbe nitrogen competition in a detailed grassland 15 N tracer study and found that competition theories in current ESMs fail to capture observed patterns and the ECA prediction simplifies the complex nature of nutrient competition and quantitatively matches the 15 N observations. Since plant carbon dynamics are strongly modulated by soil nutrient acquisition, we conclude that (1) predicted nutrient limitation effects on terrestrial carbon accumulation by existing ESMs may be biased and (2) our ECA-based approach may improve predictions by mechanistically representing plant-microbe nutrient competition. © 2016 by the Ecological Society of America.

  5. Evaluating remedial alternatives for an acid mine drainage stream: a model post audit.

    PubMed

    Runkel, Robert L; Kimball, Briant A; Walton-Day, Katherine; Verplanck, Philip L; Broshears, Robert E

    2012-01-03

    A post audit for a reactive transport model used to evaluate acid mine drainage treatment systems is presented herein. The post audit is based on a paired synoptic approach in which hydrogeochemical data are collected at low (existing conditions) and elevated (following treatment) pH. Data obtained under existing, low-pH conditions are used for calibration, and the resultant model is used to predict metal concentrations observed following treatment. Predictions for Al, As, Fe, H(+), and Pb accurately reproduce the observed reduction in dissolved concentrations afforded by the treatment system, and the information provided in regard to standard attainment is also accurate (predictions correctly indicate attainment or nonattainment of water quality standards for 19 of 25 cases). Errors associated with Cd, Cu, and Zn are attributed to misspecification of sorbent mass (precipitated Fe). In addition to these specific results, the post audit provides insight in regard to calibration and sensitivity analysis that is contrary to conventional wisdom. Steps taken during the calibration process to improve simulations of As sorption were ultimately detrimental to the predictive results, for example, and the sensitivity analysis failed to bracket observed metal concentrations.

  6. Bayesian Revision of Residual Detection Power

    NASA Technical Reports Server (NTRS)

    DeLoach, Richard

    2013-01-01

    This paper addresses some issues with quality assessment and quality assurance in response surface modeling experiments executed in wind tunnels. The role of data volume on quality assurance for response surface models is reviewed. Specific wind tunnel response surface modeling experiments are considered for which apparent discrepancies exist between fit quality expectations based on implemented quality assurance tactics, and the actual fit quality achieved in those experiments. These discrepancies are resolved by using Bayesian inference to account for certain imperfections in the assessment methodology. Estimates of the fraction of out-of-tolerance model predictions based on traditional frequentist methods are revised to account for uncertainty in the residual assessment process. The number of sites in the design space for which residuals are out of tolerance is seen to exceed the number of sites where the model actually fails to fit the data. A method is presented to estimate how much of the design space in inadequately modeled by low-order polynomial approximations to the true but unknown underlying response function.

  7. ProMotE: an efficient algorithm for counting independent motifs in uncertain network topologies.

    PubMed

    Ren, Yuanfang; Sarkar, Aisharjya; Kahveci, Tamer

    2018-06-26

    Identifying motifs in biological networks is essential in uncovering key functions served by these networks. Finding non-overlapping motif instances is however a computationally challenging task. The fact that biological interactions are uncertain events further complicates the problem, as it makes the existence of an embedding of a given motif an uncertain event as well. In this paper, we develop a novel method, ProMotE (Probabilistic Motif Embedding), to count non-overlapping embeddings of a given motif in probabilistic networks. We utilize a polynomial model to capture the uncertainty. We develop three strategies to scale our algorithm to large networks. Our experiments demonstrate that our method scales to large networks in practical time with high accuracy where existing methods fail. Moreover, our experiments on cancer and degenerative disease networks show that our method helps in uncovering key functional characteristics of biological networks.

  8. A Novel User Created Message Application Service Design for Bidirectional TPEG

    NASA Astrophysics Data System (ADS)

    Lee, Sang-Hee; Jo, Kang-Hyun

    The T-DMB (Terrestrial-Digital Multimedia Broadcasting) is the national service, currently successful in use in Korea since 2008. Among other services, TPEG (Transport Protocol Experts Group) service has been spotlighted in the aspects of creating earnings. At present, TPEG service is not so popular as it fails to satisfy the user’s demands on various aspects. Thus, the variety of services including bidirectional service is necessary in stage of DMB2.0. In this paper, the limitations of existing TPEG-POI (Point of Interest) application service using the wireless communication network are indicated. To overcome such limitations, we propose a business model for TPEG-UCM (User Created Message) application service which uses individual bidirectional media. The experiment shown in this paper proves the usability and operability of the proposed method, suggesting that the implementation of the proposed method would be overcome a lack of variety and unidirectional of existing TPEG application.

  9. Structural and functional identification of vasculogenic mimicry in vitro.

    PubMed

    Racordon, Dusan; Valdivia, Andrés; Mingo, Gabriel; Erices, Rafaela; Aravena, Raúl; Santoro, Felice; Bravo, Maria Loreto; Ramirez, Carolina; Gonzalez, Pamela; Sandoval, Alejandra; González, Alfonso; Retamal, Claudio; Kogan, Marcelo J; Kato, Sumie; Cuello, Mauricio A; Osorio, German; Nualart, Francisco; Alvares, Pedro; Gago-Arias, Araceli; Fabri, Daniella; Espinoza, Ignacio; Sanchez, Beatriz; Corvalán, Alejandro H; Pinto, Mauricio P; Owen, Gareth I

    2017-08-01

    Vasculogenic mimicry (VM) describes a process by which cancer cells establish an alternative perfusion pathway in an endothelial cell-free manner. Despite its strong correlation with reduced patient survival, controversy still surrounds the existence of an in vitro model of VM. Furthermore, many studies that claim to demonstrate VM fail to provide solid evidence of true hollow channels, raising concerns as to whether actual VM is actually being examined. Herein, we provide a standardized in vitro assay that recreates the formation of functional hollow channels using ovarian cancer cell lines, cancer spheres and primary cultures derived from ovarian cancer ascites. X-ray microtomography 3D-reconstruction, fluorescence confocal microscopy and dye microinjection conclusively confirm the existence of functional glycoprotein-rich lined tubular structures in vitro and demonstrate that many of structures reported in the literature may not represent VM. This assay may be useful to design and test future VM-blocking anticancer therapies.

  10. A portal to validated websites on cosmetic surgery: the design of an archetype.

    PubMed

    Parikh, A R; Kok, K; Redfern, B; Clarke, A; Withey, S; Butler, P E M

    2006-09-01

    There has recently been an increase in the usage of the Internet as a source of patient information. It is very difficult for laypersons to establish the accuracy and validity of these medical websites. Although many website assessment tools exist, most of these are not practical.A combination of consumer- and clinician-based website assessment tools was applied to 200 websites on cosmetic surgery. The top-scoring websites were used as links from a portal website that was designed using Microsoft Macromedia Suite.Seventy-one (35.5%) websites were excluded. One hundred fifteen websites (89%) failed to reach an acceptable standard.The provision of new websites has proceeded without quality controls. Patients need to be better educated on the limitations of the Internet. This paper suggests an archetypal model, which makes efficient use of existing resources, validates them, and is easily transferable to different health settings.

  11. Making science worthwhile: still seeking critical, not cosmetic, changes

    NASA Astrophysics Data System (ADS)

    Tonso, Karen L.

    2014-06-01

    Tonso's commentary on Sinnes and Løken's paper links what they found to empirical research done in science and engineering career settings. Sinnes and Løken's findings are a welcome addition to a literature dedicated to pointing out, yet again, some of the reasons we have made so little progress reversing gender inequities in the last 35 years. Their critique of Project Lily adds to what we know about initiatives that fail to grasp the futility of depending on either changing women so they become a better fit in STEM fields (few women exist of this sort) or highlighting those aspects of STEM fields perceived as attractive to underrepresented communities (the masculinized downside will still exist). Sinnes and Løken thus join a growing literature calling for cultural change in STEM disciplines and careers and providing a model feminist critique that other scholars can use to challenge similar initiatives.

  12. Simulation-Based Training for Colonoscopy

    PubMed Central

    Preisler, Louise; Svendsen, Morten Bo Søndergaard; Nerup, Nikolaj; Svendsen, Lars Bo; Konge, Lars

    2015-01-01

    Abstract The aim of this study was to create simulation-based tests with credible pass/fail standards for 2 different fidelities of colonoscopy models. Only competent practitioners should perform colonoscopy. Reliable and valid simulation-based tests could be used to establish basic competency in colonoscopy before practicing on patients. Twenty-five physicians (10 consultants with endoscopic experience and 15 fellows with very little endoscopic experience) were tested on 2 different simulator models: a virtual-reality simulator and a physical model. Tests were repeated twice on each simulator model. Metrics with discriminatory ability were identified for both modalities and reliability was determined. The contrasting-groups method was used to create pass/fail standards and the consequences of these were explored. The consultants significantly performed faster and scored higher than the fellows on both the models (P < 0.001). Reliability analysis showed Cronbach α = 0.80 and 0.87 for the virtual-reality and the physical model, respectively. The established pass/fail standards failed one of the consultants (virtual-reality simulator) and allowed one fellow to pass (physical model). The 2 tested simulations-based modalities provided reliable and valid assessments of competence in colonoscopy and credible pass/fail standards were established for both the tests. We propose to use these standards in simulation-based training programs before proceeding to supervised training on patients. PMID:25634177

  13. Cohesive phase-field fracture and a PDE constrained optimization approach to fracture inverse problems

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

    Tupek, Michael R.

    2016-06-30

    In recent years there has been a proliferation of modeling techniques for forward predictions of crack propagation in brittle materials, including: phase-field/gradient damage models, peridynamics, cohesive-zone models, and G/XFEM enrichment techniques. However, progress on the corresponding inverse problems has been relatively lacking. Taking advantage of key features of existing modeling approaches, we propose a parabolic regularization of Barenblatt cohesive models which borrows extensively from previous phase-field and gradient damage formulations. An efficient explicit time integration strategy for this type of nonlocal fracture model is then proposed and justified. In addition, we present a C++ computational framework for computing in- putmore » parameter sensitivities efficiently for explicit dynamic problems using the adjoint method. This capability allows for solving inverse problems involving crack propagation to answer interesting engineering questions such as: 1) what is the optimal design topology and material placement for a heterogeneous structure to maximize fracture resistance, 2) what loads must have been applied to a structure for it to have failed in an observed way, 3) what are the existing cracks in a structure given various experimental observations, etc. In this work, we focus on the first of these engineering questions and demonstrate a capability to automatically and efficiently compute optimal designs intended to minimize crack propagation in structures.« less

  14. The Origin, Early Evolution and Predictability of Solar Eruptions

    NASA Astrophysics Data System (ADS)

    Green, Lucie M.; Török, Tibor; Vršnak, Bojan; Manchester, Ward; Veronig, Astrid

    2018-02-01

    Coronal mass ejections (CMEs) were discovered in the early 1970s when space-borne coronagraphs revealed that eruptions of plasma are ejected from the Sun. Today, it is known that the Sun produces eruptive flares, filament eruptions, coronal mass ejections and failed eruptions; all thought to be due to a release of energy stored in the coronal magnetic field during its drastic reconfiguration. This review discusses the observations and physical mechanisms behind this eruptive activity, with a view to making an assessment of the current capability of forecasting these events for space weather risk and impact mitigation. Whilst a wealth of observations exist, and detailed models have been developed, there still exists a need to draw these approaches together. In particular more realistic models are encouraged in order to asses the full range of complexity of the solar atmosphere and the criteria for which an eruption is formed. From the observational side, a more detailed understanding of the role of photospheric flows and reconnection is needed in order to identify the evolutionary path that ultimately means a magnetic structure will erupt.

  15. Selection against Heteroplasmy Explains the Evolution of Uniparental Inheritance of Mitochondria

    PubMed Central

    Christie, Joshua R.; Schaerf, Timothy M.; Beekman, Madeleine

    2015-01-01

    Why are mitochondria almost always inherited from one parent during sexual reproduction? Current explanations for this evolutionary mystery include conflict avoidance between the nuclear and mitochondrial genomes, clearing of deleterious mutations, and optimization of mitochondrial-nuclear coadaptation. Mathematical models, however, fail to show that uniparental inheritance can replace biparental inheritance under any existing hypothesis. Recent empirical evidence indicates that mixing two different but normal mitochondrial haplotypes within a cell (heteroplasmy) can cause cell and organism dysfunction. Using a mathematical model, we test if selection against heteroplasmy can lead to the evolution of uniparental inheritance. When we assume selection against heteroplasmy and mutations are neither advantageous nor deleterious (neutral mutations), uniparental inheritance replaces biparental inheritance for all tested parameter values. When heteroplasmy involves mutations that are advantageous or deleterious (non-neutral mutations), uniparental inheritance can still replace biparental inheritance. We show that uniparental inheritance can evolve with or without pre-existing mating types. Finally, we show that selection against heteroplasmy can explain why some organisms deviate from strict uniparental inheritance. Thus, we suggest that selection against heteroplasmy explains the evolution of uniparental inheritance. PMID:25880558

  16. Cooperative behaviour and prosocial reputation dynamics in a Dominican village.

    PubMed

    Macfarlan, Shane J; Quinlan, Robert; Remiker, Mark

    2013-06-22

    Prosocial reputations play an important role, from the evolution of language to Internet transactions; however, questions remain about their behavioural correlates and dynamics. Formal models assume prosocial reputations correlate with the number of cooperative acts one performs; however, if reputations flow through information networks, then the number of individuals one assists may be a better proxy. Formal models demonstrate indirect experience must track behaviour with the same fidelity as direct experience for reputations to become viable; however, research on corporate reputations suggests performance change does not always affect reputation change. Debate exists over the cognitive mechanisms employed for assessing reputation dynamics. Image scoring suggests reputations fluctuate relative to the number of times one fails to assist others in need, while standing strategy claims reputations fluctuate relative to the number of times one fails to assist others in good standing. This study examines the behavioural correlates of prosocial reputations and their dynamics over a 20-month period in an Afro-Caribbean village. Analyses suggest prosocial reputations: (i) are correlated with the number of individuals one assists in economic production, not the number of cooperative acts; (ii) track cooperative behaviour, but are anchored across time; and (iii) are captured neither by image scoring nor standing strategy-type mechanisms.

  17. The Sydney Heart Bank: improving translational research while eliminating or reducing the use of animal models of human heart disease.

    PubMed

    Dos Remedios, C G; Lal, S P; Li, A; McNamara, J; Keogh, A; Macdonald, P S; Cooke, R; Ehler, E; Knöll, R; Marston, S B; Stelzer, J; Granzier, H; Bezzina, C; van Dijk, S; De Man, F; Stienen, G J M; Odeberg, J; Pontén, F; Linke, W; van der Velden, J

    2017-08-01

    The Sydney Heart Bank (SHB) is one of the largest human heart tissue banks in existence. Its mission is to provide high-quality human heart tissue for research into the molecular basis of human heart failure by working collaboratively with experts in this field. We argue that, by comparing tissues from failing human hearts with age-matched non-failing healthy donor hearts, the results will be more relevant than research using animal models, particularly if their physiology is very different from humans. Tissue from heart surgery must generally be used soon after collection or it significantly deteriorates. Freezing is an option but it raises concerns that freezing causes substantial damage at the cellular and molecular level. The SHB contains failing samples from heart transplant patients and others who provided informed consent for the use of their tissue for research. All samples are cryopreserved in liquid nitrogen within 40 min of their removal from the patient, and in less than 5-10 min in the case of coronary arteries and left ventricle samples. To date, the SHB has collected tissue from about 450 failing hearts (>15,000 samples) from patients with a wide range of etiologies as well as increasing numbers of cardiomyectomy samples from patients with hypertrophic cardiomyopathy. The Bank also has hearts from over 120 healthy organ donors whose hearts, for a variety of reasons (mainly tissue-type incompatibility with waiting heart transplant recipients), could not be used for transplantation. Donor hearts were collected by the St Vincent's Hospital Heart and Lung transplantation team from local hospitals or within a 4-h jet flight from Sydney. They were flushed with chilled cardioplegic solution and transported to Sydney where they were quickly cryopreserved in small samples. Failing and/or donor samples have been used by more than 60 research teams around the world, and have resulted in more than 100 research papers. The tissues most commonly requested are from donor left ventricles, but right ventricles, atria, interventricular system, and coronary arteries vessels have also been reported. All tissues are stored for long-term use in liquid N or vapor (170-180 °C), and are shipped under nitrogen vapor to avoid degradation of sensitive molecules such as RNAs and giant proteins. We present evidence that the availability of these human heart samples has contributed to a reduction in the use of animal models of human heart failure.

  18. Distant supervision for neural relation extraction integrated with word attention and property features.

    PubMed

    Qu, Jianfeng; Ouyang, Dantong; Hua, Wen; Ye, Yuxin; Li, Ximing

    2018-04-01

    Distant supervision for neural relation extraction is an efficient approach to extracting massive relations with reference to plain texts. However, the existing neural methods fail to capture the critical words in sentence encoding and meanwhile lack useful sentence information for some positive training instances. To address the above issues, we propose a novel neural relation extraction model. First, we develop a word-level attention mechanism to distinguish the importance of each individual word in a sentence, increasing the attention weights for those critical words. Second, we investigate the semantic information from word embeddings of target entities, which can be developed as a supplementary feature for the extractor. Experimental results show that our model outperforms previous state-of-the-art baselines. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. A minimum distance estimation approach to the two-sample location-scale problem.

    PubMed

    Zhang, Zhiyi; Yu, Qiqing

    2002-09-01

    As reported by Kalbfleisch and Prentice (1980), the generalized Wilcoxon test fails to detect a difference between the lifetime distributions of the male and female mice died from Thymic Leukemia. This failure is a result of the test's inability to detect a distributional difference when a location shift and a scale change exist simultaneously. In this article, we propose an estimator based on the minimization of an average distance between two independent quantile processes under a location-scale model. Large sample inference on the proposed estimator, with possible right-censorship, is discussed. The mouse leukemia data are used as an example for illustration purpose.

  20. Topological Distances Between Brain Networks

    PubMed Central

    Lee, Hyekyoung; Solo, Victor; Davidson, Richard J.; Pollak, Seth D.

    2018-01-01

    Many existing brain network distances are based on matrix norms. The element-wise differences may fail to capture underlying topological differences. Further, matrix norms are sensitive to outliers. A few extreme edge weights may severely affect the distance. Thus it is necessary to develop network distances that recognize topology. In this paper, we introduce Gromov-Hausdorff (GH) and Kolmogorov-Smirnov (KS) distances. GH-distance is often used in persistent homology based brain network models. The superior performance of KS-distance is contrasted against matrix norms and GH-distance in random network simulations with the ground truths. The KS-distance is then applied in characterizing the multimodal MRI and DTI study of maltreated children.

  1. Modelling root reinforcement in shallow forest soils

    USGS Publications Warehouse

    Skaugset, Arne E.

    1997-01-01

    A hypothesis used to explain the relationship between timber harvesting and landslides is that tree roots add mechanical support to soil, thus increasing soil strength. Upon harvest, the tree roots decay which reduces soil strength and increases the risk of management -induced landslides. The technical literature does not adequately support this hypothesis. Soil strength values attributed to root reinforcement that are in the technical literature are such that forested sites can't fail and all high risk, harvested sites must fail. Both unstable forested sites and stable harvested sites exist, in abundance, in the real world thus, the literature does not adequately describe the real world. An analytical model was developed to calculate soil strength increase due to root reinforcement. Conceptually, the model is composed of a reinforcing element with high tensile strength, i.e. a conifer root, embedded in a material with little tensile strength, i.e. a soil. As the soil fails and deforms, the reinforcing element also deforms and stretches. The lateral deformation of the reinforcing element is treated analytically as a laterally loaded pile in a flexible foundation and the axial deformation is treated as an axially loaded pile. The governing differential equations are solved using finite-difference approximation techniques. The root reinforcement model was tested by comparing the final shape of steel and aluminum rods, parachute cord, wooden dowels, and pine roots in direct shear with predicted shapes from the output of the root reinforcement model. The comparisons were generally satisfactory, were best for parachute cord and wooden dowels, and were poorest for steel and aluminum rods. A parameter study was performed on the root reinforcement model which showed reinforced soil strength increased with increasing root diameter and soil depth. Output from the root reinforcement model showed a strain incompatibility between large and small diameter roots. The peak increase in soil strength attributed to roots was controlled by the small (<4mm) diameter root fraction. These results were used to calculate the effect of timber harvesting on a small, approximately 7.6 m3 (10 yd3), hypothetical landslide in a shallow, cohesionless, forest soil. The root reinforcement model predicted a post-harvest reduction in soil strength of 14 and 19 percent for a soil with and without 5 kPa (105 lbs/ft2) of cohesion, respectively.

  2. An improved correlation to predict molecular weight between crosslinks based on equilibrium degree of swelling of hydrogel networks.

    PubMed

    Jimenez-Vergara, Andrea C; Lewis, John; Hahn, Mariah S; Munoz-Pinto, Dany J

    2018-04-01

    Accurate characterization of hydrogel diffusional properties is of substantial importance for a range of biotechnological applications. The diffusional capacity of hydrogels has commonly been estimated using the average molecular weight between crosslinks (M c ), which is calculated based on the equilibrium degree of swelling. However, the existing correlation linking M c and equilibrium swelling fails to accurately reflect the diffusional properties of highly crosslinked hydrogel networks. Also, as demonstrated herein, the current model fails to accurately predict the diffusional properties of hydrogels when polymer concentration and molecular weight are varied simultaneously. To address these limitations, we evaluated the diffusional properties of 48 distinct hydrogel formulations using two different photoinitiator systems, employing molecular size exclusion as an alternative methodology to calculate average hydrogel mesh size. The resulting data were then utilized to develop a revised correlation between M c and hydrogel equilibrium swelling that substantially reduces the limitations associated with the current correlation. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1339-1348, 2018. © 2017 Wiley Periodicals, Inc.

  3. 7 CFR 15a.4 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... be satisfactory to the Secretary if the applicant or recipient to whom such assurance applies fails... eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  4. 7 CFR 15a.4 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... be satisfactory to the Secretary if the applicant or recipient to whom such assurance applies fails... eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  5. 7 CFR 15a.4 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... be satisfactory to the Secretary if the applicant or recipient to whom such assurance applies fails... eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  6. 7 CFR 15a.4 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... be satisfactory to the Secretary if the applicant or recipient to whom such assurance applies fails... eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  7. U.S. Patent Pending, Cyberspace Security System for Complex Systems, U.S. Patent Application No.: 14/134,949

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

    Abercrombie, Robert K; Sheldon, Frederick T; Mili, Ali

    A computer implemented method monetizes the security of a cyber-system in terms of losses each stakeholder may expect to lose if a security break down occurs. A non-transitory media stores instructions for generating a stake structure that includes costs that each stakeholder of a system would lose if the system failed to meet security requirements and generating a requirement structure that includes probabilities of failing requirements when computer components fails. The system generates a vulnerability model that includes probabilities of a component failing given threats materializing and generates a perpetrator model that includes probabilities of threats materializing. The system generatesmore » a dot product of the stakes structure, the requirement structure, the vulnerability model and the perpetrator model. The system can further be used to compare, contrast and evaluate alternative courses of actions best suited for the stakeholders and their requirements.« less

  8. Hierarchical Bayesian modelling of gene expression time series across irregularly sampled replicates and clusters.

    PubMed

    Hensman, James; Lawrence, Neil D; Rattray, Magnus

    2013-08-20

    Time course data from microarrays and high-throughput sequencing experiments require simple, computationally efficient and powerful statistical models to extract meaningful biological signal, and for tasks such as data fusion and clustering. Existing methodologies fail to capture either the temporal or replicated nature of the experiments, and often impose constraints on the data collection process, such as regularly spaced samples, or similar sampling schema across replications. We propose hierarchical Gaussian processes as a general model of gene expression time-series, with application to a variety of problems. In particular, we illustrate the method's capacity for missing data imputation, data fusion and clustering.The method can impute data which is missing both systematically and at random: in a hold-out test on real data, performance is significantly better than commonly used imputation methods. The method's ability to model inter- and intra-cluster variance leads to more biologically meaningful clusters. The approach removes the necessity for evenly spaced samples, an advantage illustrated on a developmental Drosophila dataset with irregular replications. The hierarchical Gaussian process model provides an excellent statistical basis for several gene-expression time-series tasks. It has only a few additional parameters over a regular GP, has negligible additional complexity, is easily implemented and can be integrated into several existing algorithms. Our experiments were implemented in python, and are available from the authors' website: http://staffwww.dcs.shef.ac.uk/people/J.Hensman/.

  9. Proposed roadmap for overcoming legal and financial obstacles to carbon capture and sequestration

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

    Jacobs, Wendy; Chohen, Leah; Kostakidis-Lianos, Leah

    Many existing proposals either lack sufficient concreteness to make carbon capture and geological sequestration (CCGS) operational or fail to focus on a comprehensive, long term framework for its regulation, thus failing to account adequately for the urgency of the issue, the need to develop immediate experience with large scale demonstration projects, or the financial and other incentives required to launch early demonstration projects. We aim to help fill this void by proposing a roadmap to commercial deployment of CCGS in the United States.This roadmap focuses on the legal and financial incentives necessary for rapid demonstration of geological sequestration in themore » absence of national restrictions on CO2 emissions. It weaves together existing federal programs and financing opportunities into a set of recommendations for achieving commercial viability of geological sequestration.« less

  10. Dynamic non-equilibrium wall-modeling for large eddy simulation at high Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Kawai, Soshi; Larsson, Johan

    2013-01-01

    A dynamic non-equilibrium wall-model for large-eddy simulation at arbitrarily high Reynolds numbers is proposed and validated on equilibrium boundary layers and a non-equilibrium shock/boundary-layer interaction problem. The proposed method builds on the prior non-equilibrium wall-models of Balaras et al. [AIAA J. 34, 1111-1119 (1996)], 10.2514/3.13200 and Wang and Moin [Phys. Fluids 14, 2043-2051 (2002)], 10.1063/1.1476668: the failure of these wall-models to accurately predict the skin friction in equilibrium boundary layers is shown and analyzed, and an improved wall-model that solves this issue is proposed. The improvement stems directly from reasoning about how the turbulence length scale changes with wall distance in the inertial sublayer, the grid resolution, and the resolution-characteristics of numerical methods. The proposed model yields accurate resolved turbulence, both in terms of structure and statistics for both the equilibrium and non-equilibrium flows without the use of ad hoc corrections. Crucially, the model accurately predicts the skin friction, something that existing non-equilibrium wall-models fail to do robustly.

  11. Modern meta-heuristics based on nonlinear physics processes: A review of models and design procedures

    NASA Astrophysics Data System (ADS)

    Salcedo-Sanz, S.

    2016-10-01

    Meta-heuristic algorithms are problem-solving methods which try to find good-enough solutions to very hard optimization problems, at a reasonable computation time, where classical approaches fail, or cannot even been applied. Many existing meta-heuristics approaches are nature-inspired techniques, which work by simulating or modeling different natural processes in a computer. Historically, many of the most successful meta-heuristic approaches have had a biological inspiration, such as evolutionary computation or swarm intelligence paradigms, but in the last few years new approaches based on nonlinear physics processes modeling have been proposed and applied with success. Non-linear physics processes, modeled as optimization algorithms, are able to produce completely new search procedures, with extremely effective exploration capabilities in many cases, which are able to outperform existing optimization approaches. In this paper we review the most important optimization algorithms based on nonlinear physics, how they have been constructed from specific modeling of a real phenomena, and also their novelty in terms of comparison with alternative existing algorithms for optimization. We first review important concepts on optimization problems, search spaces and problems' difficulty. Then, the usefulness of heuristics and meta-heuristics approaches to face hard optimization problems is introduced, and some of the main existing classical versions of these algorithms are reviewed. The mathematical framework of different nonlinear physics processes is then introduced as a preparatory step to review in detail the most important meta-heuristics based on them. A discussion on the novelty of these approaches, their main computational implementation and design issues, and the evaluation of a novel meta-heuristic based on Strange Attractors mutation will be carried out to complete the review of these techniques. We also describe some of the most important application areas, in broad sense, of meta-heuristics, and describe free-accessible software frameworks which can be used to make easier the implementation of these algorithms.

  12. Too Big to Fail, Too Big to Exist Act

    THOMAS, 113th Congress

    Sen. Sanders, Bernard [I-VT

    2013-04-09

    Senate - 04/09/2013 Read twice and referred to the Committee on Banking, Housing, and Urban Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  13. Some Ethical-Moral Concerns in Administration.

    ERIC Educational Resources Information Center

    Enns, Frederick

    1981-01-01

    Presents and analyzes moral-ethical issues that arise in administration and concludes that past descriptive, objective, and scientific approaches to administration have failed to take full account of the moral-ethical dimension of human existence. (Author/WD)

  14. Illiquidity premium and expected stock returns in the UK: A new approach

    NASA Astrophysics Data System (ADS)

    Chen, Jiaqi; Sherif, Mohamed

    2016-09-01

    This study examines the relative importance of liquidity risk for the time-series and cross-section of stock returns in the UK. We propose a simple way to capture the multidimensionality of illiquidity. Our analysis indicates that existing illiquidity measures have considerable asset specific components, which justifies our new approach. Further, we use an alternative test of the Amihud (2002) measure and parametric and non-parametric methods to investigate whether liquidity risk is priced in the UK. We find that the inclusion of the illiquidity factor in the capital asset pricing model plays a significant role in explaining the cross-sectional variation in stock returns, in particular with the Fama-French three-factor model. Further, using Hansen-Jagannathan non-parametric bounds, we find that the illiquidity-augmented capital asset pricing models yield a small distance error, other non-liquidity based models fail to yield economically plausible distance values. Our findings have important implications for managing the liquidity risk of equity portfolios.

  15. A Very Large Area Network (VLAN) knowledge-base applied to space communication problems

    NASA Technical Reports Server (NTRS)

    Zander, Carol S.

    1988-01-01

    This paper first describes a hierarchical model for very large area networks (VLAN). Space communication problems whose solution could profit by the model are discussed and then an enhanced version of this model incorporating the knowledge needed for the missile detection-destruction problem is presented. A satellite network or VLAN is a network which includes at least one satellite. Due to the complexity, a compromise between fully centralized and fully distributed network management has been adopted. Network nodes are assigned to a physically localized group, called a partition. Partitions consist of groups of cell nodes with one cell node acting as the organizer or master, called the Group Master (GM). Coordinating the group masters is a Partition Master (PM). Knowledge is also distributed hierarchically existing in at least two nodes. Each satellite node has a back-up earth node. Knowledge must be distributed in such a way so as to minimize information loss when a node fails. Thus the model is hierarchical both physically and informationally.

  16. Low Activation Joining of SiC/SiC Composites for Fusion Applications: Modeling Miniature Torsion Tests with Elastic and Elastic-Plastic Models

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

    Henager, Charles H.; Nguyen, Ba Nghiep; Kurtz, Richard J.

    2015-03-01

    The use of SiC and SiC-composites in fission or fusion environments requires joining methods for assembling systems. The international fusion community designed miniature torsion specimens for joint testing and irradiation in test reactors with limited irradiation volumes. These torsion specimens fail out-of-plane when joints are strong and when elastic moduli are within a certain range compared to SiC, which causes difficulties in determining shear strengths for joints or for comparing unirradiated and irradiated joints. A finite element damage model was developed that indicates fracture is likely to occur within the joined pieces to cause out-of-plane failures for miniature torsion specimensmore » when a certain modulus and strength ratio between the joint material and the joined material exists. The model was extended to treat elastic-plastic joints such as SiC/epoxy and steel/epoxy joints tested as validation of the specimen design.« less

  17. Chinese culture and dental behaviour: some observations from Wellington.

    PubMed

    Zhang, W

    2009-03-01

    Chinese migrants bring their Chinese culture and Chinese beliefs to New Zealand. The acculturation process can be long and may affect their access to dental services. Analysis of recent research suggests a pattern whereby the greater the acculturation, the greater the use of dental services. Four aspects of Chinese culture are highlighted: wrong perception of the cause of caries as 'Qi'; intention to seek self-treatment; a preference for keeping teeth against dentists' advice; and complex attitudes towards New Zealand dentists. These issues require dentists to be culturally aware when dealing with Chinese patients. Because existing models fail to capture the complexities of Chinese culture, a dynamic model is proposed to help dental practitioners to understand Chinese migrants' dental behaviours. Chinese culture also has implications for researchers who want to carry out research with the Chinese community.

  18. Measuring the Outcome of At-Risk Students on Biology Standardized Tests When Using Different Instructional Strategies

    NASA Astrophysics Data System (ADS)

    Burns, Dana

    Over the last two decades, online education has become a popular concept in universities as well as K-12 education. This generation of students has grown up using technology and has shown interest in incorporating technology into their learning. The idea of using technology in the classroom to enhance student learning and create higher achievement has become necessary for administrators, teachers, and policymakers. Although online education is a popular topic, there has been minimal research on the effectiveness of online and blended learning strategies compared to the student learning in a traditional K-12 classroom setting. The purpose of this study was to investigate differences in standardized test scores from the Biology End of Course exam when at-risk students completed the course using three different educational models: online format, blended learning, and traditional face-to-face learning. Data was collected from over 1,000 students over a five year time period. Correlation analyzed data from standardized tests scores of eighth grade students was used to define students as "at-risk" for failing high school courses. The results indicated a high correlation between eighth grade standardized test scores and Biology End of Course exam scores. These students were deemed "at-risk" for failing high school courses. Standardized test scores were measured for the at-risk students when those students completed Biology in the different models of learning. Results indicated significant differences existed among the learning models. Students had the highest test scores when completing Biology in the traditional face-to-face model. Further evaluation of subgroup populations indicated statistical differences in learning models for African-American populations, female students, and for male students.

  19. A prospect theory explanation of the disposition to trade losing investments for less than market price.

    PubMed

    Johnstone, D J

    2002-06-01

    Investors have a proven general reluctance to realize losses. The theory of "mental accounting" suggests that losses are easier to accept when mentally integrated with either preceding losses or with compensatory gains. Mental integration is made easier when a failed asset is exchanged against a new, apparently profitable, acquisition. The alternative is to sell the existing asset on the open market before re-investing the proceeds as desired. This is emotionally less appealing than "rolling over" a losing investment into a new venture by way of an asset trade. The psychological benefits of exchanging rather than selling a failed asset come at a cost. It is typical of trade-in arrangements, e.g., where one trades an old car against a new one, that the effective sale price of the existing asset is less than current market value. Acceptance of this low price adds to the investor's total monetary loss on the existing asset but is essential to an overall package deal apart from which that asset would often remain belatedly unsold.

  20. Predicting on-road assessment pass and fail outcomes in older drivers with cognitive impairment using a battery of computerized sensory-motor and cognitive tests.

    PubMed

    Hoggarth, Petra A; Innes, Carrie R H; Dalrymple-Alford, John C; Jones, Richard D

    2013-12-01

    To generate a robust model of computerized sensory-motor and cognitive test performance to predict on-road driving assessment outcomes in older persons with diagnosed or suspected cognitive impairment. A logistic regression model classified pass–fail outcomes of a blinded on-road driving assessment. Generalizability of the model was tested using leave-one-out cross-validation. Three specialist clinics in New Zealand. Drivers (n=279; mean age 78.4, 65% male) with diagnosed or suspected dementia, mild cognitive impairment, unspecified cognitive impairment, or memory problems referred for a medical driving assessment. A computerized battery of sensory-motor and cognitive tests and an on-road medical driving assessment. One hundred fifty-five participants (55.5%) received an on-road fail score. Binary logistic regression correctly classified 75.6% of the sample into on-road pass and fail groups. The cross-validation indicated accuracy of the model of 72.0% with sensitivity for detecting on-road fails of 73.5%, specificity of 70.2%, positive predictive value of 75.5%, and negative predictive value of 68%. The off-road assessment prediction model resulted in a substantial number of people who were assessed as likely to fail despite passing an on-road assessment and vice versa. Thus, despite a large multicenter sample, the use of off-road tests previously found to be useful in other older populations, and a carefully constructed and tested prediction model, off-road measures have yet to be found that are sufficiently accurate to allow acceptable determination of on-road driving safety of cognitively impaired older drivers. © 2013, Copyright the Authors Journal compilation © 2013, The American Geriatrics Society.

  1. NS5806 partially restores action potential duration but fails to ameliorate calcium transient dysfunction in a computational model of canine heart failure.

    PubMed

    Maleckar, Mary M; Lines, Glenn T; Koivumäki, Jussi T; Cordeiro, Jonathan M; Calloe, Kirstine

    2014-11-01

    The study investigates how increased Ito, as mediated by the activator NS5806, affects excitation-contraction coupling in chronic heart failure (HF). We hypothesized that restoring spike-and-dome morphology of the action potential (AP) to a healthy phenotype would be insufficient to restore the intracellular Ca(2) (+) transient (CaT), due to HF-induced remodelling of Ca(2+) handling. An existing mathematical model of the canine ventricular myocyte was modified to incorporate recent experimental data from healthy and failing myocytes, resulting in models of both healthy and HF epicardial, midmyocardial, and endocardial cell variants. Affects of NS5806 were also included in HF models through its direct interaction with Kv4.3 and Kv1.4. Single-cell simulations performed in all models (control, HF, and HF + drug) and variants (epi, mid, and endo) assessed AP morphology and underlying ionic processes with a focus on calcium transients (CaT), how these were altered in HF across the ventricular wall, and the subsequent effects of varying compound concentration in HF. Heart failure model variants recapitulated a characteristic increase in AP duration (APD) in the disease. The qualitative effects of application of half-maximal effective concentration (EC50) of NS5806 on APs and CaT are heterogeneous and non-linear. Deepening in the AP notch with drug is a direct effect of the activation of Ito; both Ito and consequent alteration of IK1 kinetics cause decrease in AP plateau potential. Decreased APD50 and APD90 are both due to altered IK1. Analysis revealed that drug effects depend on transmurality. Ca(2+) transient morphology changes-increased amplitude and shorter time to peak-are due to direct increase in ICa,L and indirect larger SR Ca(2+) release subsequent to Ito activation. Downstream effects of a compound acting exclusively on sarcolemmal ion channels are difficult to predict. Remediation of APD to pre-failing state does not ameliorate dysfunction in CaT; however, restoration of notch depth appears to impart modest benefit and a likelihood of therapeutic value in modulating early repolarization. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

  2. Malthusian dynamics in a diverging Europe: Northern Italy, 1650-1881.

    PubMed

    Fernihough, Alan

    2013-02-01

    Recent empirical research questions the validity of using Malthusian theory in preindustrial England. Using real wage and vital rate data for the years 1650-1881, I provide empirical estimates for a different region: Northern Italy. The empirical methodology is theoretically underpinned by a simple Malthusian model, in which population, real wages, and vital rates are determined endogenously. My findings strongly support the existence of a Malthusian economy wherein population growth decreased living standards, which in turn influenced vital rates. However, these results also demonstrate how the system is best characterized as one of weak homeostasis. Furthermore, there is no evidence of Boserupian effects given that increases in population failed to spur any sustained technological progress.

  3. Finite GUE Distribution with Cut-Off at a Shock

    NASA Astrophysics Data System (ADS)

    Ferrari, P. L.

    2018-03-01

    We consider the totally asymmetric simple exclusion process with initial conditions generating a shock. The fluctuations of particle positions are asymptotically governed by the randomness around the two characteristic lines joining at the shock. Unlike in previous papers, we describe the correlation in space-time without employing the mapping to the last passage percolation, which fails to exists already for the partially asymmetric model. We then consider a special case, where the asymptotic distribution is a cut-off of the distribution of the largest eigenvalue of a finite GUE matrix. Finally we discuss the strength of the probabilistic and physically motivated approach and compare it with the mathematical difficulties of a direct computation.

  4. Testing our scenario of a failed wind in TW Hya

    NASA Astrophysics Data System (ADS)

    Canizares, Claude

    2017-09-01

    We recently discovered variability in X-ray indicators of accretion in the CTTS TW Hya. We seek to use this to understand the physics of accretion in our upcoming HST observations. We have been granted 7 HST orbits to monitor the C IV 155 nm doublet in TW Hya, the closest CTTS, to correlate i) the hot wind ii) the cool wind iii) the photometric period iv) the accretion. In existing HETGS data of TW Hya we see variability in emission lines from the accretion shock on the star. However, the densities in Ne IX and O VII indicate that today's shock models are incomplete. A hot wind is the most promising candidate for this missing component.

  5. Investigating Individual Differences in Toddler Search with Mixture Models

    ERIC Educational Resources Information Center

    Berthier, Neil E.; Boucher, Kelsea; Weisner, Nina

    2015-01-01

    Children's performance on cognitive tasks is often described in categorical terms in that a child is described as either passing or failing a test, or knowing or not knowing some concept. We used binomial mixture models to determine whether individual children could be classified as passing or failing two search tasks, the DeLoache model room…

  6. Cascading Failures in Bi-partite Graphs: Model for Systemic Risk Propagation

    PubMed Central

    Huang, Xuqing; Vodenska, Irena; Havlin, Shlomo; Stanley, H. Eugene

    2013-01-01

    As economic entities become increasingly interconnected, a shock in a financial network can provoke significant cascading failures throughout the system. To study the systemic risk of financial systems, we create a bi-partite banking network model composed of banks and bank assets and propose a cascading failure model to describe the risk propagation process during crises. We empirically test the model with 2007 US commercial banks balance sheet data and compare the model prediction of the failed banks with the real failed banks after 2007. We find that our model efficiently identifies a significant portion of the actual failed banks reported by Federal Deposit Insurance Corporation. The results suggest that this model could be useful for systemic risk stress testing for financial systems. The model also identifies that commercial rather than residential real estate assets are major culprits for the failure of over 350 US commercial banks during 2008–2011. PMID:23386974

  7. Towards a damage tolerance philosophy for composite materials and structures

    NASA Technical Reports Server (NTRS)

    O'Brien, T. Kevin

    1990-01-01

    A damage-threshold/fail-safe approach is proposed to ensure that composite structures are both sufficiently durable for economy of operation, as well as adequately fail-safe or damage tolerant for flight safety. Matrix cracks are assumed to exist throughout the off-axis plies. Delamination onset is predicted using a strain energy release rate characterization. Delamination growth is accounted for in one of three ways: either analytically, using delamination growth laws in conjunction with strain energy release rate analyses incorporating delamination resistance curves; experimentally, using measured stiffness loss; or conservatively, assuming delamination onset corresponds to catastrophic delamination growth. Fail-safety is assessed by accounting for the accumulation of delaminations through the thickness. A tension fatigue life prediction for composite laminates is presented as a case study to illustrate how this approach may be implemented. Suggestions are made for applying the damage-threshold/fail-safe approach to compression fatigue, tension/compression fatigue, and compression strength following low velocity impact.

  8. Towards a damage tolerance philosophy for composite materials and structures

    NASA Technical Reports Server (NTRS)

    Obrien, T. Kevin

    1988-01-01

    A damage-threshold/fail-safe approach is proposed to ensure that composite structures are both sufficiently durable for economy of operation, as well as adequately fail-safe or damage tolerant for flight safety. Matrix cracks are assumed to exist throughout the off-axis plies. Delamination onset is predicted using a strain energy release rate characterization. Delamination growth is accounted for in one of three ways: either analytically, using delamination growth laws in conjunction with strain energy release rate analyses incorporating delamination resistance curves; experimentally, using measured stiffness loss; or conservatively, assuming delamination onset corresponds to catastrophic delamination growth. Fail-safety is assessed by accounting for the accumulation of delaminations through the thickness. A tension fatigue life prediction for composite laminates is presented as a case study to illustrate how this approach may be implemented. Suggestions are made for applying the damage-threshold/fail-safe approach to compression fatigue, tension/compression fatigue, and compression strength following low velocity impact.

  9. Reprint of "Safe places for pedestrians: using cognitive work analysis to consider the relationships between the engineering and urban design of footpaths".

    PubMed

    Stevens, Nicholas; Salmon, Paul

    2015-01-01

    Footpaths provide an integral component of our urban environments and have the potential to act as safe places for people and the focus for community life. Despite this, the approach to designing footpaths that are safe while providing this sense of place often occurs in silos. There is often very little consideration given to how designing for sense of place impacts safety and vice versa. The aim of this study was to use a systems analysis and design framework to develop a design template for an 'ideal' footpath system that embodies both safety and sense of place. This was achieved through using the first phase of the Cognitive Work Analysis framework, Work Domain Analysis, to specify a model of footpaths as safe places for pedestrians. This model was subsequently used to assess two existing footpath environments to determine the extent to which they meet the design requirements specified. The findings show instances where the existing footpaths both meet and fail to meet the design requirements specified. Through utilising a systems approach for footpaths, this paper has provided a novel design template that can inform new footpath design efforts or be used to evaluate the extent to which existing footpaths achieve their safety and sense of place requirements. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Safe places for pedestrians: using cognitive work analysis to consider the relationships between the engineering and urban design of footpaths.

    PubMed

    Stevens, Nicholas; Salmon, Paul

    2014-11-01

    Footpaths provide an integral component of our urban environments and have the potential to act as safe places for people and the focus for community life. Despite this, the approach to designing footpaths that are safe while providing this sense of place often occurs in silos. There is often very little consideration given to how designing for sense of place impacts safety and vice versa. The aim of this study was to use a systems analysis and design framework to develop a design template for an 'ideal' footpath system that embodies both safety and sense of place. This was achieved through using the first phase of the Cognitive Work Analysis framework, Work Domain Analysis, to specify a model of footpaths as safe places for pedestrians. This model was subsequently used to assess two existing footpath environments to determine the extent to which they meet the design requirements specified. The findings show instances where the existing footpaths both meet and fail to meet the design requirements specified. Through utilising a systems approach for footpaths, this paper has provided a novel design template that can inform new footpath design efforts or be used to evaluate the extent to which existing footpaths achieve their safety and sense of place requirements. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Measuring and Advancing Experimental Design Ability in an Introductory Course without Altering Existing Lab Curriculum†

    PubMed Central

    Shanks, Ryan A.; Robertson, Chuck L.; Haygood, Christian S.; Herdliksa, Anna M.; Herdliska, Heather R.; Lloyd, Steven A.

    2017-01-01

    Introductory biology courses provide an important opportunity to prepare students for future courses, yet existing cookbook labs, although important in their own way, fail to provide many of the advantages of semester-long research experiences. Engaging, authentic research experiences aid biology students in meeting many learning goals. Therefore, overlaying a research experience onto the existing lab structure allows faculty to overcome barriers involving curricular change. Here we propose a working model for this overlay design in an introductory biology course and detail a means to conduct this lab with minimal increases in student and faculty workloads. Furthermore, we conducted exploratory factor analysis of the Experimental Design Ability Test (EDAT) and uncovered two latent factors which provide valid means to assess this overlay model’s ability to increase advanced experimental design abilities. In a pre-test/post-test design, we demonstrate significant increases in both basic and advanced experimental design abilities in an experimental and comparison group. We measured significantly higher gains in advanced experimental design understanding in students in the experimental group. We believe this overlay model and EDAT factor analysis contribute a novel means to conduct and assess the effectiveness of authentic research experiences in an introductory course without major changes to the course curriculum and with minimal increases in faculty and student workloads. PMID:28904647

  12. Increased Cardiac Myocyte Progenitors in Failing Human Hearts

    PubMed Central

    Kubo, Hajime; Jaleel, Naser; Kumarapeli, Asangi; Berretta, Remus M.; Bratinov, George; Shan, Xiaoyin; Wang, Hongmei; Houser, Steven R.; Margulies, Kenneth B.

    2009-01-01

    Background Increasing evidence, derived mainly from animal models, supports the existence of endogenous cardiac renewal and repair mechanisms in adult mammalian hearts that could contribute to normal homeostasis and the responses to pathological insults. Methods and Results Translating these results, we isolated small c-kit+ cells from 36 of 37 human hearts using primary cell isolation techniques and magnetic cell sorting techniques. The abundance of these cardiac progenitor cells was increased nearly 4-fold in patients with heart failure requiring transplantation compared with nonfailing controls. Polychromatic flow cytometry of primary cell isolates (<30 μm) without antecedent c-kit enrichment confirmed the increased abundance of c-kit+ cells in failing hearts and demonstrated frequent coexpression of CD45 in these cells. Immunocytochemical characterization of freshly isolated, c-kit–enriched human cardiac progenitor cells confirmed frequent coexpression of c-kit and CD45. Primary cardiac progenitor cells formed new human cardiac myocytes at a relatively high frequency after coculture with neonatal rat ventricular myocytes. These contracting new cardiac myocytes exhibited an immature phenotype and frequent electric coupling with the rat myocytes that induced their myogenic differentiation. Conclusions Despite the increased abundance and cardiac myogenic capacity of cardiac progenitor cells in failing human hearts, the need to replace these organs via transplantation implies that adverse features of the local myocardial environment overwhelm endogenous cardiac repair capacity. Developing strategies to improve the success of endogenous cardiac regenerative processes may permit therapeutic myocardial repair without cell delivery per se. PMID:18645055

  13. The HPS experiment

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

    Colaneri, Luca

    2017-04-01

    With the experimental discovery of the Higgs boson, the Standard Model has been considered veri ed in all its previsions. The Standard Model, though, is still considered an incomplete theory, because it fails to address many theoretical and phenomenological issues. Among those, it doesn't provide any viable Dark Matter candidate. Many Beyond-Standard Model theories, such as the Supersymmetric Standard Model, provide possible solutions. In this work we have reported the experimental observations that led to considerate the existence of a new Force, mediated by a new massive vector boson, that could address all the observed phenomenology. This new dark Forcemore » could open an observational channel between the Standard Model and a new Dark Sector, convey by the interaction of the Standard Model photon with the massive dark photon, also called the A'. Purpose of this work was to develop an independent study of the background processes and the implementation of an independent event generator, to better understand the kinematics of the produced particles in the process e - +W → e - +W' + e + + e - and validate, or invalidate, the o cial event generator.« less

  14. Population models for passerine birds: structure, parameterization, and analysis

    USGS Publications Warehouse

    Noon, B.R.; Sauer, J.R.; McCullough, D.R.; Barrett, R.H.

    1992-01-01

    Population models have great potential as management tools, as they use infonnation about the life history of a species to summarize estimates of fecundity and survival into a description of population change. Models provide a framework for projecting future populations, determining the effects of management decisions on future population dynamics, evaluating extinction probabilities, and addressing a variety of questions of ecological and evolutionary interest. Even when insufficient information exists to allow complete identification of the model, the modelling procedure is useful because it forces the investigator to consider the life history of the species when determining what parameters should be estimated from field studies and provides a context for evaluating the relative importance of demographic parameters. Models have been little used in the study of the population dynamics of passerine birds because of: (1) widespread misunderstandings of the model structures and parameterizations, (2) a lack of knowledge of life histories of many species, (3) difficulties in obtaining statistically reliable estimates of demographic parameters for most passerine species, and (4) confusion about functional relationships among demographic parameters. As a result, studies of passerine demography are often designed inappropriately and fail to provide essential data. We review appropriate models for passerine bird populations and illustrate their possible uses in evaluating the effects of management or other environmental influences on population dynamics. We identify environmental influences on population dynamics. We identify parameters that must be estimated from field data, briefly review existing statistical methods for obtaining valid estimates, and evaluate the present status of knowledge of these parameters.

  15. Relaxing the σ 8-tension through running vacuum in the Universe

    NASA Astrophysics Data System (ADS)

    Gómez-Valent, Adrià; Solà, Joan

    2017-11-01

    It has recently been shown that the class of running vacuum models (RVMs) has the capacity to fit the overall cosmological observations better than the concordance ΛCDM model, therefore supporting the possibility of dynamical dark energy (DE). Apart from the cosmic microwave background (CMB) anisotropies, the most crucial datasets involved are: i) baryonic acoustic oscillations (BAO), and ii) direct large scale structure (LSS) formation data. Analyses mainly focusing on CMB and with insufficient BAO + LSS input generally fail to capture the dynamical DE signature, whereas the few existing studies accounting for the wealth of known CMB+BAO+LSS data (see in particular Solà, Gómez-Valent and de Cruz Pérez (2015), (2017); and Zhao et al. (2017)) do converge to the remarkable conclusion that dynamical DE might well be encoded in the current cosmological observations at 3-4σ c.l. A decisive factor is the persistent σ 8-tension between the ΛCDM and the data. Because the issue is obviously pressing, we devote this work to explain how and why running vacuum in the expanding universe successfully relaxes the existing σ 8-tension and describes the LSS formation data significantly better than the ΛCDM.

  16. Assessing the Role of Inhibition in Stabilizing Neocortical Networks Requires Large-Scale Perturbation of the Inhibitory Population

    PubMed Central

    Mrsic-Flogel, Thomas D.

    2017-01-01

    Neurons within cortical microcircuits are interconnected with recurrent excitatory synaptic connections that are thought to amplify signals (Douglas and Martin, 2007), form selective subnetworks (Ko et al., 2011), and aid feature discrimination. Strong inhibition (Haider et al., 2013) counterbalances excitation, enabling sensory features to be sharpened and represented by sparse codes (Willmore et al., 2011). This balance between excitation and inhibition makes it difficult to assess the strength, or gain, of recurrent excitatory connections within cortical networks, which is key to understanding their operational regime and the computations that they perform. Networks that combine an unstable high-gain excitatory population with stabilizing inhibitory feedback are known as inhibition-stabilized networks (ISNs) (Tsodyks et al., 1997). Theoretical studies using reduced network models predict that ISNs produce paradoxical responses to perturbation, but experimental perturbations failed to find evidence for ISNs in cortex (Atallah et al., 2012). Here, we reexamined this question by investigating how cortical network models consisting of many neurons behave after perturbations and found that results obtained from reduced network models fail to predict responses to perturbations in more realistic networks. Our models predict that a large proportion of the inhibitory network must be perturbed to reliably detect an ISN regime robustly in cortex. We propose that wide-field optogenetic suppression of inhibition under promoters targeting a large fraction of inhibitory neurons may provide a perturbation of sufficient strength to reveal the operating regime of cortex. Our results suggest that detailed computational models of optogenetic perturbations are necessary to interpret the results of experimental paradigms. SIGNIFICANCE STATEMENT Many useful computational mechanisms proposed for cortex require local excitatory recurrence to be very strong, such that local inhibitory feedback is necessary to avoid epileptiform runaway activity (an “inhibition-stabilized network” or “ISN” regime). However, recent experimental results suggest that this regime may not exist in cortex. We simulated activity perturbations in cortical networks of increasing realism and found that, to detect ISN-like properties in cortex, large proportions of the inhibitory population must be perturbed. Current experimental methods for inhibitory perturbation are unlikely to satisfy this requirement, implying that existing experimental observations are inconclusive about the computational regime of cortex. Our results suggest that new experimental designs targeting a majority of inhibitory neurons may be able to resolve this question. PMID:29074575

  17. The Objective Borderline Method (OBM): A Probability-Based Model for Setting up an Objective Pass/Fail Cut-Off Score in Medical Programme Assessments

    ERIC Educational Resources Information Center

    Shulruf, Boaz; Turner, Rolf; Poole, Phillippa; Wilkinson, Tim

    2013-01-01

    The decision to pass or fail a medical student is a "high stakes" one. The aim of this study is to introduce and demonstrate the feasibility and practicality of a new objective standard-setting method for determining the pass/fail cut-off score from borderline grades. Three methods for setting up pass/fail cut-off scores were compared: the…

  18. How to make thermodynamic perturbation theory to be suitable for low temperature?

    NASA Astrophysics Data System (ADS)

    Zhou, Shiqi

    2009-02-01

    Low temperature unsuitability is a problem plaguing thermodynamic perturbation theory (TPT) for years. Present investigation indicates that the low temperature predicament can be overcome by employing as reference system a nonhard sphere potential which incorporates one part of the attractive ingredient in a potential function of interest. In combination with a recently proposed TPT [S. Zhou, J. Chem. Phys. 125, 144518 (2006)] based on a λ expansion (λ being coupling parameter), the new perturbation strategy is employed to predict for several model potentials. It is shown that the new perturbation strategy can very accurately predict various thermodynamic properties even if the potential range is extremely short and hence the temperature of interest is very low and current theoretical formalisms seriously deteriorate or critically fail to predict even the existence of the critical point. Extensive comparison with existing liquid state theories and available computer simulation data discloses a superiority of the present TPT to two Ornstein-Zernike-type integral equation theories, i.e., hierarchical reference theory and self-consistent Ornstein-Zernike approximation.

  19. Underdamped scaled Brownian motion: (non-)existence of the overdamped limit in anomalous diffusion.

    PubMed

    Bodrova, Anna S; Chechkin, Aleksei V; Cherstvy, Andrey G; Safdari, Hadiseh; Sokolov, Igor M; Metzler, Ralf

    2016-07-27

    It is quite generally assumed that the overdamped Langevin equation provides a quantitative description of the dynamics of a classical Brownian particle in the long time limit. We establish and investigate a paradigm anomalous diffusion process governed by an underdamped Langevin equation with an explicit time dependence of the system temperature and thus the diffusion and damping coefficients. We show that for this underdamped scaled Brownian motion (UDSBM) the overdamped limit fails to describe the long time behaviour of the system and may practically even not exist at all for a certain range of the parameter values. Thus persistent inertial effects play a non-negligible role even at significantly long times. From this study a general questions on the applicability of the overdamped limit to describe the long time motion of an anomalously diffusing particle arises, with profound consequences for the relevance of overdamped anomalous diffusion models. We elucidate our results in view of analytical and simulations results for the anomalous diffusion of particles in free cooling granular gases.

  20. How to make thermodynamic perturbation theory to be suitable for low temperature?

    PubMed

    Zhou, Shiqi

    2009-02-07

    Low temperature unsuitability is a problem plaguing thermodynamic perturbation theory (TPT) for years. Present investigation indicates that the low temperature predicament can be overcome by employing as reference system a nonhard sphere potential which incorporates one part of the attractive ingredient in a potential function of interest. In combination with a recently proposed TPT [S. Zhou, J. Chem. Phys. 125, 144518 (2006)] based on a lambda expansion (lambda being coupling parameter), the new perturbation strategy is employed to predict for several model potentials. It is shown that the new perturbation strategy can very accurately predict various thermodynamic properties even if the potential range is extremely short and hence the temperature of interest is very low and current theoretical formalisms seriously deteriorate or critically fail to predict even the existence of the critical point. Extensive comparison with existing liquid state theories and available computer simulation data discloses a superiority of the present TPT to two Ornstein-Zernike-type integral equation theories, i.e., hierarchical reference theory and self-consistent Ornstein-Zernike approximation.

  1. 3D cultured immortalized human hepatocytes useful to develop drugs for blood-borne HCV

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

    Aly, Hussein Hassan; Shimotohno, Kunitada; Hijikata, Makoto

    2009-02-06

    Due to the high polymorphism of natural hepatitis C virus (HCV) variants, existing recombinant HCV replication models have failed to be effective in developing effective anti-HCV agents. In the current study, we describe an in vitro system that supports the infection and replication of natural HCV from patient blood using an immortalized primary human hepatocyte cell line cultured in a three-dimensional (3D) culture system. Comparison of the gene expression profile of cells cultured in the 3D system to those cultured in the existing 2D system demonstrated an up-regulation of several genes activated by peroxisome proliferator-activated receptor alpha (PPAR{alpha}) signaling. Furthermore,more » using PPAR{alpha} agonists and antagonists, we also analyzed the effect of PPAR{alpha} signaling on the modulation of HCV replication using this system. The 3D in vitro system described in this study provides significant insight into the search for novel anti-HCV strategies that are specific to various strains of HCV.« less

  2. Competitive Cyber-Insurance and Internet Security

    NASA Astrophysics Data System (ADS)

    Shetty, Nikhil; Schwartz, Galina; Felegyhazi, Mark; Walrand, Jean

    This paper investigates how competitive cyber-insurers affect network security and welfare of the networked society. In our model, a user's probability to incur damage (from being attacked) depends on both his security and the network security, with the latter taken by individual users as given. First, we consider cyberinsurers who cannot observe (and thus, affect) individual user security. This asymmetric information causes moral hazard. Then, for most parameters, no equilibrium exists: the insurance market is missing. Even if an equilibrium exists, the insurance contract covers only a minor fraction of the damage; network security worsens relative to the no-insurance equilibrium. Second, we consider insurers with perfect information about their users' security. Here, user security is perfectly enforceable (zero cost); each insurance contract stipulates the required user security. The unique equilibrium contract covers the entire user damage. Still, for most parameters, network security worsens relative to the no-insurance equilibrium. Although cyber-insurance improves user welfare, in general, competitive cyber-insurers fail to improve network security.

  3. The reliability of the pass/fail decision for assessments comprised of multiple components.

    PubMed

    Möltner, Andreas; Tımbıl, Sevgi; Jünger, Jana

    2015-01-01

    The decision having the most serious consequences for a student taking an assessment is the one to pass or fail that student. For this reason, the reliability of the pass/fail decision must be determined for high quality assessments, just as the measurement reliability of the point values. Assessments in a particular subject (graded course credit) are often composed of multiple components that must be passed independently of each other. When "conjunctively" combining separate pass/fail decisions, as with other complex decision rules for passing, adequate methods of analysis are necessary for estimating the accuracy and consistency of these classifications. To date, very few papers have addressed this issue; a generally applicable procedure was published by Douglas and Mislevy in 2010. Using the example of an assessment comprised of several parts that must be passed separately, this study analyzes the reliability underlying the decision to pass or fail students and discusses the impact of an improved method for identifying those who do not fulfill the minimum requirements. The accuracy and consistency of the decision to pass or fail an examinee in the subject cluster Internal Medicine/General Medicine/Clinical Chemistry at the University of Heidelberg's Faculty of Medicine was investigated. This cluster requires students to separately pass three components (two written exams and an OSCE), whereby students may reattempt to pass each component twice. Our analysis was carried out using the method described by Douglas and Mislevy. Frequently, when complex logical connections exist between the individual pass/fail decisions in the case of low failure rates, only a very low reliability for the overall decision to grant graded course credit can be achieved, even if high reliabilities exist for the various components. For the example analyzed here, the classification accuracy and consistency when conjunctively combining the three individual parts is relatively low with κ=0.49 or κ=0.47, despite the good reliability of over 0.75 for each of the three components. The option to repeat each component twice leads to a situation in which only about half of the candidates who do not satisfy the minimum requirements would fail the overall assessment, while the other half is able to continue their studies despite having deficient knowledge and skills. The method put forth by Douglas and Mislevy allows the analysis of the decision accuracy and consistency for complex combinations of scores from different components. Even in the case of highly reliable components, it is not necessarily so that a reliable pass/fail decision has been reached - for instance in the case of low failure rates. Assessments must be administered with the explicit goal of identifying examinees that do not fulfill the minimum requirements.

  4. The reliability of the pass/fail decision for assessments comprised of multiple components

    PubMed Central

    Möltner, Andreas; Tımbıl, Sevgi; Jünger, Jana

    2015-01-01

    Objective: The decision having the most serious consequences for a student taking an assessment is the one to pass or fail that student. For this reason, the reliability of the pass/fail decision must be determined for high quality assessments, just as the measurement reliability of the point values. Assessments in a particular subject (graded course credit) are often composed of multiple components that must be passed independently of each other. When “conjunctively” combining separate pass/fail decisions, as with other complex decision rules for passing, adequate methods of analysis are necessary for estimating the accuracy and consistency of these classifications. To date, very few papers have addressed this issue; a generally applicable procedure was published by Douglas and Mislevy in 2010. Using the example of an assessment comprised of several parts that must be passed separately, this study analyzes the reliability underlying the decision to pass or fail students and discusses the impact of an improved method for identifying those who do not fulfill the minimum requirements. Method: The accuracy and consistency of the decision to pass or fail an examinee in the subject cluster Internal Medicine/General Medicine/Clinical Chemistry at the University of Heidelberg’s Faculty of Medicine was investigated. This cluster requires students to separately pass three components (two written exams and an OSCE), whereby students may reattempt to pass each component twice. Our analysis was carried out using the method described by Douglas and Mislevy. Results: Frequently, when complex logical connections exist between the individual pass/fail decisions in the case of low failure rates, only a very low reliability for the overall decision to grant graded course credit can be achieved, even if high reliabilities exist for the various components. For the example analyzed here, the classification accuracy and consistency when conjunctively combining the three individual parts is relatively low with κ=0.49 or κ=0.47, despite the good reliability of over 0.75 for each of the three components. The option to repeat each component twice leads to a situation in which only about half of the candidates who do not satisfy the minimum requirements would fail the overall assessment, while the other half is able to continue their studies despite having deficient knowledge and skills. Conclusion: The method put forth by Douglas and Mislevy allows the analysis of the decision accuracy and consistency for complex combinations of scores from different components. Even in the case of highly reliable components, it is not necessarily so that a reliable pass/fail decision has been reached – for instance in the case of low failure rates. Assessments must be administered with the explicit goal of identifying examinees that do not fulfill the minimum requirements. PMID:26483855

  5. Structure of public transit costs in the presence of multiple serial correlation

    DOT National Transportation Integrated Search

    1999-12-01

    Most studies indicate that public transit systems operate under increasing returns to capital stock utilization and are significantly overcapitalized. Existing flexible form time series analyses, however, fail to correct for serial correlation. In th...

  6. Camera-Only Kinematics for Small Lunar Rovers

    NASA Astrophysics Data System (ADS)

    Fang, E.; Suresh, S.; Whittaker, W.

    2016-11-01

    Knowledge of the kinematic state of rovers is critical. Existing methods add sensors and wiring to moving parts, which can fail and adds mass and volume. This research presents a method to optically determine kinematic state using a single camera.

  7. Where and why do models fail? Perspectives from Oregon Hydrologic Landscape classification

    EPA Science Inventory

    A complete understanding of why rainfall-runoff models provide good streamflow predictions at catchments in some regions, but fail to do so in other regions, has still not been achieved. Here, we argue that a hydrologic classification system is a robust conceptual tool that is w...

  8. Snow Microwave Radiative Transfer (SMRT): A new model framework to simulate snow-microwave interactions for active and passive remote sensing applications

    NASA Astrophysics Data System (ADS)

    Loewe, H.; Picard, G.; Sandells, M. J.; Mätzler, C.; Kontu, A.; Dumont, M.; Maslanka, W.; Morin, S.; Essery, R.; Lemmetyinen, J.; Wiesmann, A.; Floury, N.; Kern, M.

    2016-12-01

    Forward modeling of snow-microwave interactions is widely used to interpret microwave remote sensing data from active and passive sensors. Though different models are yet available for that purpose, a joint effort has been undertaken in the past two years within the ESA Project "Microstructural origin of electromagnetic signatures in microwave remote sensing of snow". The new Snow Microwave Radiative Transfer (SMRT) model primarily facilitates a flexible treatment of snow microstructure as seen by X-ray tomography and seeks to unite respective advantages of existing models. In its main setting, SMRT considers radiation transfer in a plane-parallel snowpack consisting of homogeneous layers with a layer microstructure represented by an autocorrelation function. The electromagnetic model, which underlies permittivity, absorption and scattering calculations within a layer, is based on the improved Born approximation. The resulting vector-radiative transfer equation in the snowpack is solved using spectral decomposition of the discrete ordinates discretization. SMRT is implemented in Python and employs an object-oriented, modular design which intends to i) provide an intuitive and fail-safe API for basic users ii) enable efficient community developments for extensions (e.g. for improvements of sub-models for microstructure, permittivity, soil or interface reflectivity) from advanced users and iii) encapsulate the numerical core which is maintained by the developers. For cross-validation and inter-model comparison, SMRT implements various ingredients of existing models as selectable options (e.g. Rayleigh or DMRT-QCA phase functions) and shallow wrappers to invoke legacy model code directly (MEMLS, DMRT-QMS, HUT). In this paper we give an overview of the model components and show examples and results from different validation schemes.

  9. Fracture Mechanics Approach to Forecasting Volcanic Eruptions

    NASA Astrophysics Data System (ADS)

    Matthews, C.; Sammonds, P.; Kilburn, C.; Woo, G.

    2008-12-01

    A medium to short-term increase in the rate of volcano-tectonic earthquake events provides one of the most useful and promising tools for eruption forecasting, particularly at subduction-zone volcanoes reawakening after a long repose interval. Two basic patterns of accelerating seismicity observed prior to eruptions are exponential and faster than exponential increases with time. While theoretical and empirical models exist that can explain these observed trends, less is known about seismic unrest at volcanoes that does not end in eruption. A comprehensive model of fracturing and failure within an edifice must also explain why volcanoes do not erupt. We have developed a numerical fracture mechanical model for simulating precursory seismic sequences, associated with the opening of a new magmatic pathway to the surface. The model reproduces the basic patterns of precursory seismicity and shows that the signals produced vary according to changes in the extent of damage and in the mechanical properties of the host rock. Local stress conditions and material property distributions exist under which the model is also able to produce seismic swarms that do not lead to failure and eruption. It can therefore provide insight into factors determining whether or not a seismic crisis leads to eruption. Critically, when combined with field data this may provide information on how often 'failed' eruptions can be expected, or suggest a step towards an observational method for distinguishing between a seismic swarm leading to quiescence and a pre-eruptive seismic sequence.

  10. Global MHD Simulations of the Earth's Bow Shock Shape and Motion Under Variable Solar Wind Conditions

    NASA Astrophysics Data System (ADS)

    Mejnertsen, L.; Eastwood, J. P.; Hietala, H.; Schwartz, S. J.; Chittenden, J. P.

    2018-01-01

    Empirical models of the Earth's bow shock are often used to place in situ measurements in context and to understand the global behavior of the foreshock/bow shock system. They are derived statistically from spacecraft bow shock crossings and typically treat the shock surface as a conic section parameterized according to a uniform solar wind ram pressure, although more complex models exist. Here a global magnetohydrodynamic simulation is used to analyze the variability of the Earth's bow shock under real solar wind conditions. The shape and location of the bow shock is found as a function of time, and this is used to calculate the shock velocity over the shock surface. The results are compared to existing empirical models. Good agreement is found in the variability of the subsolar shock location. However, empirical models fail to reproduce the two-dimensional shape of the shock in the simulation. This is because significant solar wind variability occurs on timescales less than the transit time of a single solar wind phase front over the curved shock surface. Empirical models must therefore be used with care when interpreting spacecraft data, especially when observations are made far from the Sun-Earth line. Further analysis reveals a bias to higher shock speeds when measured by virtual spacecraft. This is attributed to the fact that the spacecraft only observes the shock when it is in motion. This must be accounted for when studying bow shock motion and variability with spacecraft data.

  11. CH(+) Destruction by Reaction with H: Computing Quantum Rates To Model Different Molecular Regions in the Interstellar Medium.

    PubMed

    Bovino, S; Grassi, T; Gianturco, F A

    2015-12-17

    A detailed analysis of an ionic reaction that plays a crucial role in the carbon chemistry of the interstellar medium (ISM) is carried out by computing ab initio reactive cross sections with a quantum method and by further obtaining the corresponding CH(+) destruction rates over a range of temperatures that shows good overall agreement with existing experiments. The differences found between all existing calculations and the very-low-T experiments are discussed and explored via a simple numerical model that links these cross section reductions to collinear approaches where nonadiabatic crossing is expected to dominate. The new rates are further linked to a complex chemical network that models the evolution of the CH(+) abundance in the photodissociation region (PDR) and molecular cloud (MC) environments of the ISM. The abundances of CH(+) are given by numerical solutions of a large set of coupled, first-order kinetics equations that employs our new chemical package krome. The analysis that we carry out reveals that the important region for CH(+) destruction is that above 100 K, hence showing that, at least for this reaction, the differences with the existing laboratory low-T experiments are of essentially no importance within the astrochemical environments discussed here because, at those temperatures, other chemical processes involving the title molecule are taking over. A detailed analysis of the chemical network involving CH(+) also shows that a slight decrease in the initial oxygen abundance might lead to higher CH(+) abundances because the main chemical carbon ion destruction channel is reduced in efficiency. This might provide an alternative chemical route to understand the reason why general astrochemical models fail when the observed CH(+) abundances are matched with the outcomes of their calculations.

  12. Kaqchikel midwives, home births, and emergency obstetric referrals in Guatemala: contextualizing the choice to stay at home.

    PubMed

    Berry, Nicole S

    2006-04-01

    Maternal mortality is highest in those countries whose health budgets are restricted. Practical strategies employed in the International Safe Motherhood Initiative, therefore, must be both effective and economical. Investing in emergency obstetric care resources has been touted as one such strategy. This investment aims to insure significant improvements are made in regional health centers, and a chain of referral is put into place so that only problem cases are attended by the most skilled health workers. This article examines how this model of referral functions in Sololá, Guatemala, where most Kaqchikel Mayan women give birth at home with a traditional midwife, and no skilled biomedical attendant is available at the birth to make a referral. Ethnographic data is used to explore reasons why women do not go to the hospital at the first sign of difficulty. I argue that the problem frequently is not that Mayan midwives, their clients and families fail to understand the biomedical information about dangers in birth, but rather that this information fails to fit into an already existing social system of understanding birth and birth-related knowledge.

  13. Research note: Mapping spatial patterns in sewer age, material, and proximity to surface waterways to infer sewer leakage hotspots

    USGS Publications Warehouse

    Hopkins, Kristina G.; Bain, Daniel J.

    2018-01-01

    Identifying areas where deteriorating sewer infrastructure is in close proximity to surface waterways is needed to map likely connections between sewers and streams. We present a method to estimate sewer installation year and deterioration status using historical maps of the sewer network, parcel-scale property assessment data, and pipe material. Areas where streams were likely buried into the sewer system were mapped by intersecting the historical stream network derived from a 10-m resolution digital elevation model with sewer pipe locations. Potential sewer leakage hotspots were mapped by identifying where aging sewer pipes are in close proximity (50-m) to surface waterways. Results from Pittsburgh, Pennsylvania (USA), indicated 41% of the historical stream length was lost or buried and the potential interface between sewers and streams is great. The co-location of aging sewer infrastructure (>75 years old) near stream channels suggests that 42% of existing streams are located in areas with a high potential for sewer leakage if sewer infrastructure fails. Mapping the sewer-stream interface provides an approach to better understand areas were failing sewers may contribute a disproportional amount of nutrients and other pathogens to surface waterways.

  14. Long-term social bonds promote cooperation in the iterated Prisoner's Dilemma.

    PubMed

    St-Pierre, Angèle; Larose, Karine; Dubois, Frédérique

    2009-12-07

    Reciprocal altruism, one of the most probable explanations for cooperation among non-kin, has been modelled as a Prisoner's Dilemma. According to this game, cooperation could evolve when individuals, who expect to play again, use conditional strategies like tit-for-tat or Pavlov. There is evidence that humans use such strategies to achieve mutual cooperation, but most controlled experiments with non-human animals have failed to find cooperation. One reason for this could be that subjects fail to cooperate because they behave as if they were to play only once. To assess this hypothesis, we conducted an experiment with monogamous zebra finches (Taeniopygia guttata) that were tested in a two-choice apparatus, with either their social partner or an experimental opponent of the opposite sex. We found that zebra finches maintained high levels of cooperation in an iterated Prisoner's Dilemma game only when interacting with their social partner. Although other mechanisms may have contributed to the observed difference between the two treatments, our results support the hypothesis that animals do not systematically give in to the short-term temptation of cheating when long-term benefits exist. Thus, our findings contradict the commonly accepted idea that reciprocal altruism will be rare in non-human animals.

  15. Climate change, species distribution models, and physiological performance metrics: predicting when biogeographic models are likely to fail.

    PubMed

    Woodin, Sarah A; Hilbish, Thomas J; Helmuth, Brian; Jones, Sierra J; Wethey, David S

    2013-09-01

    Modeling the biogeographic consequences of climate change requires confidence in model predictions under novel conditions. However, models often fail when extended to new locales, and such instances have been used as evidence of a change in physiological tolerance, that is, a fundamental niche shift. We explore an alternative explanation and propose a method for predicting the likelihood of failure based on physiological performance curves and environmental variance in the original and new environments. We define the transient event margin (TEM) as the gap between energetic performance failure, defined as CTmax, and the upper lethal limit, defined as LTmax. If TEM is large relative to environmental fluctuations, models will likely fail in new locales. If TEM is small relative to environmental fluctuations, models are likely to be robust for new locales, even when mechanism is unknown. Using temperature, we predict when biogeographic models are likely to fail and illustrate this with a case study. We suggest that failure is predictable from an understanding of how climate drives nonlethal physiological responses, but for many species such data have not been collected. Successful biogeographic forecasting thus depends on understanding when the mechanisms limiting distribution of a species will differ among geographic regions, or at different times, resulting in realized niche shifts. TEM allows prediction of the likelihood of such model failure.

  16. Testing the gravitational instability hypothesis?

    NASA Technical Reports Server (NTRS)

    Babul, Arif; Weinberg, David H.; Dekel, Avishai; Ostriker, Jeremiah P.

    1994-01-01

    We challenge a widely accepted assumption of observational cosmology: that successful reconstruction of observed galaxy density fields from measured galaxy velocity fields (or vice versa), using the methods of gravitational instability theory, implies that the observed large-scale structures and large-scale flows were produced by the action of gravity. This assumption is false, in that there exist nongravitational theories that pass the reconstruction tests and gravitational theories with certain forms of biased galaxy formation that fail them. Gravitational instability theory predicts specific correlations between large-scale velocity and mass density fields, but the same correlations arise in any model where (a) structures in the galaxy distribution grow from homogeneous initial conditions in a way that satisfies the continuity equation, and (b) the present-day velocity field is irrotational and proportional to the time-averaged velocity field. We demonstrate these assertions using analytical arguments and N-body simulations. If large-scale structure is formed by gravitational instability, then the ratio of the galaxy density contrast to the divergence of the velocity field yields an estimate of the density parameter Omega (or, more generally, an estimate of beta identically equal to Omega(exp 0.6)/b, where b is an assumed constant of proportionality between galaxy and mass density fluctuations. In nongravitational scenarios, the values of Omega or beta estimated in this way may fail to represent the true cosmological values. However, even if nongravitational forces initiate and shape the growth of structure, gravitationally induced accelerations can dominate the velocity field at late times, long after the action of any nongravitational impulses. The estimated beta approaches the true value in such cases, and in our numerical simulations the estimated beta values are reasonably accurate for both gravitational and nongravitational models. Reconstruction tests that show correlations between galaxy density and velocity fields can rule out some physically interesting models of large-scale structure. In particular, successful reconstructions constrain the nature of any bias between the galaxy and mass distributions, since processes that modulate the efficiency of galaxy formation on large scales in a way that violates the continuity equation also produce a mismatch between the observed galaxy density and the density inferred from the peculiar velocity field. We obtain successful reconstructions for a gravitational model with peaks biasing, but we also show examples of gravitational and nongravitational models that fail reconstruction tests because of more complicated modulations of galaxy formation.

  17. The Significance of Meaning: Why Do Over 90% of Behavioral Neuroscience Results Fail to Translate to Humans, and What Can We Do to Fix It?

    PubMed Central

    Garner, Joseph P.

    2014-01-01

    The vast majority of drugs entering human trials fail. This problem (called “attrition”) is widely recognized as a public health crisis, and has been discussed openly for the last two decades. Multiple recent reviews argue that animals may be just too different physiologically, anatomically, and psychologically from humans to be able to predict human outcomes, essentially questioning the justification of basic biomedical research in animals. This review argues instead that the philosophy and practice of experimental design and analysis is so different in basic animal work and human clinical trials that an animal experiment (as currently conducted) cannot reasonably predict the outcome of a human trial. Thus, attrition does reflect a lack of predictive validity of animal experiments, but it would be a tragic mistake to conclude that animal models cannot show predictive validity. A variety of contributing factors to poor validity are reviewed. The need to adopt methods and models that are highly specific (i.e., which can identify true negative results) in order to complement the current preponderance of highly sensitive methods (which are prone to false positive results) is emphasized. Concepts in biomarker-based medicine are offered as a potential solution, and changes in the use of animal models required to embrace a translational biomarker-based approach are outlined. In essence, this review advocates a fundamental shift, where we treat every aspect of an animal experiment that we can as if it was a clinical trial in a human population. However, it is unrealistic to expect researchers to adopt a new methodology that cannot be empirically justified until a successful human trial. “Validation with known failures” is proposed as a solution. Thus new methods or models can be compared against existing ones using a drug that has translated (a known positive) and one that has failed (a known negative). Current methods should incorrectly identify both as effective, but a more specific method should identify the negative compound correctly. By using a library of known failures we can thereby empirically test the impact of suggested solutions such as enrichment, controlled heterogenization, biomarker-based models, or reverse-translated measures. PMID:25541546

  18. Oral aniracetam treatment in C57BL/6J mice without pre-existing cognitive dysfunction reveals no changes in learning, memory, anxiety or stereotypy

    PubMed Central

    Reynolds, Conner D.; Jefferson, Taylor S.; Volquardsen, Meagan; Pandian, Ashvini; Smith, Gregory D.; Holley, Andrew J.; Lugo, Joaquin N.

    2017-01-01

    Background: The piracetam analog, aniracetam, has recently received attention for its cognition enhancing potential, with minimal reported side effects.  Previous studies report the drug to be effective in both human and non-human models with pre-existing cognitive dysfunction, but few studies have evaluated its efficacy in healthy subjects. A previous study performed in our laboratory found no cognitive enhancing effects of oral aniracetam administration 1-hour prior to behavioral testing in naïve C57BL/6J mice. Methods: The current study aims to further evaluate this drug by administration of aniracetam 30 minutes prior to testing in order to optimize any cognitive enhancing effects. In this study, all naïve C57BL/6J mice were tested in tasks of delayed fear conditioning, novel object recognition, rotarod, open field, elevated plus maze, and marble burying. Results: Across all tasks, animals in the treatment group failed to show enhanced learning when compared to controls. Conclusions: These results provide further evidence suggesting that aniracetam conveys no therapeutic benefit to subjects without pre-existing cognitive dysfunction. PMID:29946420

  19. A regional, market oriented governance for disaster management: A new planning approach.

    PubMed

    Blackstone, Erwin A; Hakim, Simon; Meehan, Brian

    2017-10-01

    This paper proposes a regional competitive governance and management of response and recovery from disasters. It presents problems experienced in major disasters, analyzes the failures, and suggests how a competitive system that relies on private and volunteer regional leaders, personnel, and capital can improve preparation, response and recovery efforts over the existing government system. A Public Choice approach is adopted to explain why government often fails, and how regional governance may be socially more efficient than the existing federal- state-local funded and managed disaster system. The paper suggests that the federal role might change from both funding and supplying aid in disasters to merely funding disaster recovery efforts. When a disaster occurs, available businesses and government resources in the region can be utilized under a competitive system. These resources could replace existing federal and state inventories and emergency personnel. An independent regionally controlled and managed council, which also develops its own financial resources, and local volunteer leaders are key for success. The paper suggests a new planning method that utilizes the statistical Factor Analysis methodology to derive an efficient organizational and functional model to confront disasters. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Big data need big theory too

    PubMed Central

    Dougherty, Edward R.; Highfield, Roger R.

    2016-01-01

    The current interest in big data, machine learning and data analytics has generated the widespread impression that such methods are capable of solving most problems without the need for conventional scientific methods of inquiry. Interest in these methods is intensifying, accelerated by the ease with which digitized data can be acquired in virtually all fields of endeavour, from science, healthcare and cybersecurity to economics, social sciences and the humanities. In multiscale modelling, machine learning appears to provide a shortcut to reveal correlations of arbitrary complexity between processes at the atomic, molecular, meso- and macroscales. Here, we point out the weaknesses of pure big data approaches with particular focus on biology and medicine, which fail to provide conceptual accounts for the processes to which they are applied. No matter their ‘depth’ and the sophistication of data-driven methods, such as artificial neural nets, in the end they merely fit curves to existing data. Not only do these methods invariably require far larger quantities of data than anticipated by big data aficionados in order to produce statistically reliable results, but they can also fail in circumstances beyond the range of the data used to train them because they are not designed to model the structural characteristics of the underlying system. We argue that it is vital to use theory as a guide to experimental design for maximal efficiency of data collection and to produce reliable predictive models and conceptual knowledge. Rather than continuing to fund, pursue and promote ‘blind’ big data projects with massive budgets, we call for more funding to be allocated to the elucidation of the multiscale and stochastic processes controlling the behaviour of complex systems, including those of life, medicine and healthcare. This article is part of the themed issue ‘Multiscale modelling at the physics–chemistry–biology interface’. PMID:27698035

  1. Big data need big theory too.

    PubMed

    Coveney, Peter V; Dougherty, Edward R; Highfield, Roger R

    2016-11-13

    The current interest in big data, machine learning and data analytics has generated the widespread impression that such methods are capable of solving most problems without the need for conventional scientific methods of inquiry. Interest in these methods is intensifying, accelerated by the ease with which digitized data can be acquired in virtually all fields of endeavour, from science, healthcare and cybersecurity to economics, social sciences and the humanities. In multiscale modelling, machine learning appears to provide a shortcut to reveal correlations of arbitrary complexity between processes at the atomic, molecular, meso- and macroscales. Here, we point out the weaknesses of pure big data approaches with particular focus on biology and medicine, which fail to provide conceptual accounts for the processes to which they are applied. No matter their 'depth' and the sophistication of data-driven methods, such as artificial neural nets, in the end they merely fit curves to existing data. Not only do these methods invariably require far larger quantities of data than anticipated by big data aficionados in order to produce statistically reliable results, but they can also fail in circumstances beyond the range of the data used to train them because they are not designed to model the structural characteristics of the underlying system. We argue that it is vital to use theory as a guide to experimental design for maximal efficiency of data collection and to produce reliable predictive models and conceptual knowledge. Rather than continuing to fund, pursue and promote 'blind' big data projects with massive budgets, we call for more funding to be allocated to the elucidation of the multiscale and stochastic processes controlling the behaviour of complex systems, including those of life, medicine and healthcare.This article is part of the themed issue 'Multiscale modelling at the physics-chemistry-biology interface'. © 2015 The Authors.

  2. Software reliability studies

    NASA Technical Reports Server (NTRS)

    Wilson, Larry W.

    1989-01-01

    The longterm goal of this research is to identify or create a model for use in analyzing the reliability of flight control software. The immediate tasks addressed are the creation of data useful to the study of software reliability and production of results pertinent to software reliability through the analysis of existing reliability models and data. The completed data creation portion of this research consists of a Generic Checkout System (GCS) design document created in cooperation with NASA and Research Triangle Institute (RTI) experimenters. This will lead to design and code reviews with the resulting product being one of the versions used in the Terminal Descent Experiment being conducted by the Systems Validations Methods Branch (SVMB) of NASA/Langley. An appended paper details an investigation of the Jelinski-Moranda and Geometric models for software reliability. The models were given data from a process that they have correctly simulated and asked to make predictions about the reliability of that process. It was found that either model will usually fail to make good predictions. These problems were attributed to randomness in the data and replication of data was recommended.

  3. Non-Equilibrium Turbulence and Two-Equation Modeling

    NASA Technical Reports Server (NTRS)

    Rubinstein, Robert

    2011-01-01

    Two-equation turbulence models are analyzed from the perspective of spectral closure theories. Kolmogorov theory provides useful information for models, but it is limited to equilibrium conditions in which the energy spectrum has relaxed to a steady state consistent with the forcing at large scales; it does not describe transient evolution between such states. Transient evolution is necessarily through nonequilibrium states, which can only be found from a theory of turbulence evolution, such as one provided by a spectral closure. When the departure from equilibrium is small, perturbation theory can be used to approximate the evolution by a two-equation model. The perturbation theory also gives explicit conditions under which this model can be valid, and when it will fail. Implications of the non-equilibrium corrections for the classic Tennekes-Lumley balance in the dissipation rate equation are drawn: it is possible to establish both the cancellation of the leading order Re1/2 divergent contributions to vortex stretching and enstrophy destruction, and the existence of a nonzero difference which is finite in the limit of infinite Reynolds number.

  4. Exploration of the molecular basis of blast injury in a biofidelic model of traumatic brain injury

    NASA Astrophysics Data System (ADS)

    Thielen, P.; Mehoke, T.; Gleason, J.; Iwaskiw, A.; Paulson, J.; Merkle, A.; Wester, B.; Dymond, J.

    2018-01-01

    Biological response to blast overpressure is complex and results in various and potentially non-concomitant acute and long-term deficits to exposed individuals. Clinical links between blast severity and injury outcomes remain elusive and have yet to be fully described, resulting in a critical inability to develop associated protection and mitigation strategies. Further, experimental models frequently fail to reproduce observed physiological phenomena and/or introduce artifacts that confound analysis and reproducibility. New models are required that employ consistent mechanical inputs, scale with biological analogs and known clinical data, and permit high-throughput examination of biological responses for a range of environmental and battlefield- relevant exposures. Here we describe a novel, biofidelic headform capable of integrating complex biological samples for blast exposure studies. We additionally demonstrate its utility in detecting acute transcriptional responses in the model organism Caenorhabditis elegans after exposure to blast overpressure. This approach enables correlation between mechanical exposure and biological outcome, permitting both the enhancement of existing surrogate and computational models and the high-throughput biofidelic testing of current and future protection systems.

  5. The need for an intermediate mass scale in GUTs

    NASA Technical Reports Server (NTRS)

    Shafi, Q.

    1983-01-01

    The minimal SU(5) grand unified field theory (GUT) model fails to resolve the strong charge parity (CP) problem, suffers from the cosmological monopole problem, sheds no light on the nature of the 'dark' mass in the universe, and predicts an unacceptably low value for the baryon asymmetry. All these problems can be overcome in suitable grand unified axion models with an intermediate mass scale of about 10 to the 11th power to 10 to the 12th power GeV. An example based on the gauge group SO(10) is presented. Among other things, it predicts that the axions comprise the 'dark' mass in the universe, and that there exists a galactic monopole flux of 10 to the -8th power to 10 to the -7th power/sq cm/yr. Other topics that are briefly discussed include proton decay, family symmetry, neutrino masses and the gauge hierarchy problem.

  6. Limit on the production of a low-mass vector boson in e+e- → Uγ, U →e+e- with the KLOE experiment

    NASA Astrophysics Data System (ADS)

    Anastasi, A.; Babusci, D.; Bencivenni, G.; Berlowski, M.; Bloise, C.; Bossi, F.; Branchini, P.; Budano, A.; Caldeira Balkeståhl, L.; Cao, B.; Ceradini, F.; Ciambrone, P.; Curciarello, F.; Czerwiński, E.; D'Agostini, G.; Danè, E.; De Leo, V.; De Lucia, E.; De Santis, A.; De Simone, P.; Di Cicco, A.; Di Domenico, A.; Di Salvo, R.; Domenici, D.; D'Uffizi, A.; Fantini, A.; Felici, G.; Fiore, S.; Gajos, A.; Gauzzi, P.; Giardina, G.; Giovannella, S.; Graziani, E.; Happacher, F.; Heijkenskjöld, L.; Ikegami Andersson, W.; Johansson, T.; Kamińska, D.; Krzemien, W.; Kupsc, A.; Loffredo, S.; Mandaglio, G.; Martini, M.; Mascolo, M.; Messi, R.; Miscetti, S.; Morello, G.; Moricciani, D.; Moskal, P.; Palladino, A.; Papenbrock, M.; Passeri, A.; Patera, V.; Perez del Rio, E.; Ranieri, A.; Santangelo, P.; Sarra, I.; Schioppa, M.; Silarski, M.; Sirghi, F.; Tortora, L.; Venanzoni, G.; Wiślicki, W.; Wolke, M.

    2015-11-01

    The existence of a new force beyond the Standard Model is compelling because it could explain several striking astrophysical observations which fail standard interpretations. We searched for the light vector mediator of this dark force, the U boson, with the KLOE detector at the DAΦNE e+e- collider. Using an integrated luminosity of 1.54 fb-1, we studied the process e+e- → Uγ, with U →e+e-, using radiative return to search for a resonant peak in the dielectron invariant-mass distribution. We did not find evidence for a signal, and set a 90% CL upper limit on the mixing strength between the Standard Model photon and the dark photon, ɛ2, at 10-6-10-4 in the 5- 520 MeV /c2 mass range.

  7. Early-warning signals of critical transition: Effect of extrinsic noise

    NASA Astrophysics Data System (ADS)

    Qin, Shanshan; Tang, Chao

    2018-03-01

    Complex dynamical systems often have tipping points and exhibit catastrophic regime shift. Despite the notorious difficulty of predicting such transitions, accumulating studies have suggested the existence of generic early-warning signals (EWSs) preceding upcoming transitions. However, previous theories and models were based on the effect of the intrinsic noise (IN) when a system is approaching a critical point, and did not consider the pervasive environmental fluctuations or the extrinsic noise (EN). Here, we extend previous theory to investigate how the interplay of EN and IN affects EWSs. Stochastic simulations of model systems subject to both IN and EN have verified our theory and demonstrated that EN can dramatically alter and diminish the EWS. This effect is stronger with increasing amplitude and correlation time scale of the EN. In the presence of EN, the EWS can fail to predict or even give a false alarm of critical transitions.

  8. Psychometric properties of the Liebowitz Social Anxiety Scale (LSAS) in a longitudinal study of African Americans with anxiety disorders.

    PubMed

    Beard, Courtney; Rodriguez, Benjamin F; Moitra, Ethan; Sibrava, Nicholas J; Bjornsson, Andri; Weisberg, Risa B; Keller, Martin B

    2011-06-01

    The Liebowitz Social Anxiety Scale (LSAS) is a widely used measure of social anxiety. However, no study has examined the psychometric properties of the LSAS in an African American sample. The current study examined the LSAS characteristics in 97 African Americans diagnosed with an anxiety disorder. Overall, the original LSAS subscales showed excellent internal consistency and temporal stability. Similar to previous reports, fear and avoidance subscales were so highly correlated that they yielded redundant information. Confirmatory factor analyses for three previously proposed models failed to demonstrate an excellent fit to our data. However, a four-factor model showed minimally acceptable fit. Overall, the LSAS performed similarly in our African American sample as in previous European American samples. Exploratory factor analyses are warranted to determine whether a better factor structure exists for African Americans. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Dark Matter or Modified Dynamics? Hints from Galaxy Kinematics

    NASA Astrophysics Data System (ADS)

    Gentile, G.

    2010-12-01

    I show two observational projects I am involved in, which are aimed at understanding better the existence and nature of dark matter, and also aimed at testing alternatives to galactic dark matter such as MOND (Modified Newtonian Dynamics). I present new HI observations of the nearby dwarf galaxy NGC 3741. This galaxy has an extremely extended HI disc (42 B-band exponential scalelengths). The distribution and kinematics are accurately derived by building model data cubes, which closely reproduce the observations. Mass modelling of the rotation curve shows that a cored dark matter halo or MOND provide very good fits, whereas Cold Dark Matter density profiles fail to fit the data. I also show new results about tidal dwarf galaxies, which within the CDM framework are expected to be dark matter-free but whose kinematics instead show a mass discrepancy, exactly of the magnitude that is expected in MOND (Modified Newtonian Dynamics).

  10. Predicted space motions for hypervelocity and runaway stars: proper motions and radial velocities for the Gaia Era

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

    Kenyon, Scott J.; Brown, Warren R.; Geller, Margaret J.

    We predict the distinctive three-dimensional space motions of hypervelocity stars (HVSs) and runaway stars moving in a realistic Galactic potential. For nearby stars with distances less than 10 kpc, unbound stars are rare; proper motions alone rarely isolate bound HVSs and runaways from indigenous halo stars. At large distances of 20-100 kpc, unbound HVSs are much more common than runaways; radial velocities easily distinguish both from indigenous halo stars. Comparisons of the predictions with existing observations are encouraging. Although the models fail to match observations of solar-type HVS candidates from SEGUE, they agree well with data for B-type HVS andmore » runaways from other surveys. Complete samples of g ≲ 20 stars with Gaia should provide clear tests of formation models for HVSs and runaways and will enable accurate probes of the shape of the Galactic potential.« less

  11. Theory and computation of hot carriers generated by surface plasmon polaritons in noble metals

    PubMed Central

    Bernardi, Marco; Mustafa, Jamal; Neaton, Jeffrey B.; Louie, Steven G.

    2015-01-01

    Hot carriers (HC) generated by surface plasmon polaritons (SPPs) in noble metals are promising for application in optoelectronics, plasmonics and renewable energy. However, existing models fail to explain key quantitative details of SPP-to-HC conversion experiments. Here we develop a quantum mechanical framework and apply first-principles calculations to study the energy distribution and scattering processes of HCs generated by SPPs in Au and Ag. We find that the relative positions of the s and d bands of noble metals regulate the energy distribution and mean free path of the HCs, and that the electron–phonon interaction controls HC energy loss and transport. Our results prescribe optimal conditions for HC generation and extraction, and invalidate previously employed free-electron-like models. Our work combines density functional theory, GW and electron–phonon calculations to provide microscopic insight into HC generation and ultrafast dynamics in noble metals. PMID:26033445

  12. Sewer Project Remedies ‘Third World’ Conditions

    EPA Pesticide Factsheets

    An EPA-funded project to process sewage from homes on a West Virginia hillside has resolved what a county health department report described as “Third World” conditions caused by failing or non-existent on-site systems to manage human waste.

  13. Improved Quick Disconnect (QD) Interface Through Fail Safe Parts Identification

    NASA Technical Reports Server (NTRS)

    Blanch-Payne, Evelyn

    2001-01-01

    An extensive review of existing Quick Disconnects (QDs) mating and demating operations was performed to determine which shuttle part interface identifications and procedures contribute to human factor errors. The research methods used consisted of interviews with engineers and technicians, examination of incident reports, critiques of video and audio tapes of QD operations, and attendance of a Hyper QD operational course. The data strongly suggests that there are inherit human factor errors involved in QD operations. To promote fail-safe operations, QD interface problem areas and recommendations were outlined and reviewed. It is suggested that dialogue, investigations and recommendations continue.

  14. The application of cryogenics to high Reynolds number testing in wind tunnels. I - Evolution, theory, and advantages

    NASA Technical Reports Server (NTRS)

    Kilgore, R. A.; Dress, D. A.

    1984-01-01

    During the time which has passed since the construction of the first wind tunnel in 1870, wind tunnels have been developed to a high degree of sophistication. However, their development has consistently failed to keep pace with the demands placed on them. One of the more serious problems to be found with existing transonic wind tunnels is their inability to test subscale aircraft models at Reynolds numbers sufficiently near full-scale values to ensure the validity of using the wind tunnel data to predict flight characteristics. The Reynolds number capability of a wind tunnel may be increased by a number of different approaches. However, the best solution in terms of model, balance, and model support loads, as well as in terms of capital and operating cost appears to be related to the reduction of the temperature of the test gas to cryogenic temperatures. The present paper has the objective to review the evolution of the cryogenic wind tunnel concept and to describe its more important advantages.

  15. Decision-Tree Analysis for Predicting First-Time Pass/Fail Rates for the NCLEX-RN® in Associate Degree Nursing Students.

    PubMed

    Chen, Hsiu-Chin; Bennett, Sean

    2016-08-01

    Little evidence shows the use of decision-tree algorithms in identifying predictors and analyzing their associations with pass rates for the NCLEX-RN(®) in associate degree nursing students. This longitudinal and retrospective cohort study investigated whether a decision-tree algorithm could be used to develop an accurate prediction model for the students' passing or failing the NCLEX-RN. This study used archived data from 453 associate degree nursing students in a selected program. The chi-squared automatic interaction detection analysis of the decision trees module was used to examine the effect of the collected predictors on passing/failing the NCLEX-RN. The actual percentage scores of Assessment Technologies Institute®'s RN Comprehensive Predictor(®) accurately identified students at risk of failing. The classification model correctly classified 92.7% of the students for passing. This study applied the decision-tree model to analyze a sequence database for developing a prediction model for early remediation in preparation for the NCLEXRN. [J Nurs Educ. 2016;55(8):454-457.]. Copyright 2016, SLACK Incorporated.

  16. 77 FR 8722 - Airworthiness Directives; Eurocopter Deutschland Model EC135 Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-15

    ... that in the past, the FADEC FAIL caution light illuminated on a few EC135 T1 helicopters. It states... metering unit and transmitted to the FADEC. This discrepancy led to the display of the FADEC FAIL caution... the FADEC to automatically meter fuel, indicated by a FADEC FAIL cockpit caution light, and subsequent...

  17. 76 FR 27956 - Airworthiness Directives; Eurocopter Deutschland Model EC135 Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-13

    ... past, the FADEC FAIL caution light illuminated on a few EC135 T1 helicopters. They state that this was... transmitted to the FADEC. This discrepancy led to the display of the FADEC FAIL caution light and ``freezing... to automatically meter fuel, indicated by a FADEC FAIL cockpit caution light, and subsequent loss of...

  18. Improved darunavir genotypic mutation score predicting treatment response for patients infected with HIV-1 subtype B and non-subtype B receiving a salvage regimen.

    PubMed

    De Luca, Andrea; Flandre, Philippe; Dunn, David; Zazzi, Maurizio; Wensing, Annemarie; Santoro, Maria Mercedes; Günthard, Huldrych F; Wittkop, Linda; Kordossis, Theodoros; Garcia, Federico; Castagna, Antonella; Cozzi-Lepri, Alessandro; Churchill, Duncan; De Wit, Stéphane; Brockmeyer, Norbert H; Imaz, Arkaitz; Mussini, Cristina; Obel, Niels; Perno, Carlo Federico; Roca, Bernardino; Reiss, Peter; Schülter, Eugen; Torti, Carlo; van Sighem, Ard; Zangerle, Robert; Descamps, Diane

    2016-05-01

    The objective of this study was to improve the prediction of the impact of HIV-1 protease mutations in different viral subtypes on virological response to darunavir. Darunavir-containing treatment change episodes (TCEs) in patients previously failing PIs were selected from large European databases. HIV-1 subtype B-infected patients were used as the derivation dataset and HIV-1 non-B-infected patients were used as the validation dataset. The adjusted association of each mutation with week 8 HIV RNA change from baseline was analysed by linear regression. A prediction model was derived based on best subset least squares estimation with mutational weights corresponding to regression coefficients. Virological outcome prediction accuracy was compared with that from existing genotypic resistance interpretation systems (GISs) (ANRS 2013, Rega 9.1.0 and HIVdb 7.0). TCEs were selected from 681 subtype B-infected and 199 non-B-infected adults. Accompanying drugs were NRTIs in 87%, NNRTIs in 27% and raltegravir or maraviroc or enfuvirtide in 53%. The prediction model included weighted protease mutations, HIV RNA, CD4 and activity of accompanying drugs. The model's association with week 8 HIV RNA change in the subtype B (derivation) set was R(2) = 0.47 [average squared error (ASE) = 0.67, P < 10(-6)]; in the non-B (validation) set, ASE was 0.91. Accuracy investigated by means of area under the receiver operating characteristic curves with a binary response (above the threshold value of HIV RNA reduction) showed that our final model outperformed models with existing interpretation systems in both training and validation sets. A model with a new darunavir-weighted mutation score outperformed existing GISs in both B and non-B subtypes in predicting virological response to darunavir. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. Structural analysis of the space shuttle solid rocket booster/external tank attach ring

    NASA Technical Reports Server (NTRS)

    Dorsey, John T.

    1988-01-01

    An External Tank (ET) attach ring is used in the Space Shuttle System to transfer lateral loads between the ET and the Solid Rocket Booster (SRB). Following the Challenger (51-L) accident, the flight performance of the ET attach ring was reviewed, and negative margins of safety and failed bolts in the attach ring were subsequently identified. The analyses described in this report were performed in order to understand the existing ET attach ring structural response to motor case internal pressurization as well as to aid in an ET attach ring redesign effort undertaken by NASA LaRC. The finite element model as well as the results from linear and nonlinear static structural analyses are described.

  20. A Tissue Engineered Model of Aging: Interdependence and Cooperative Effects in Failing Tissues.

    PubMed

    Acun, A; Vural, D C; Zorlutuna, P

    2017-07-11

    Aging remains a fundamental open problem in modern biology. Although there exist a number of theories on aging on the cellular scale, nearly nothing is known about how microscopic failures cascade to macroscopic failures of tissues, organs and ultimately the organism. The goal of this work is to bridge microscopic cell failure to macroscopic manifestations of aging. We use tissue engineered constructs to control the cellular-level damage and cell-cell distance in individual tissues to establish the role of complex interdependence and interactions between cells in aging tissues. We found that while microscopic mechanisms drive aging, the interdependency between cells plays a major role in tissue death, providing evidence on how cellular aging is connected to its higher systemic consequences.

  1. Community Colleges for International Development

    ERIC Educational Resources Information Center

    Hewitt, Martin J.; Lee, Ken

    2006-01-01

    Throughout the developing world, there is a debilitating lack of connection between tertiary education and economic growth. As a result, many tertiary institutions fail to address the particular human capital needs of the productive sector, thereby constraining economic growth, productivity and innovation. Existing employment opportunities go…

  2. Asking the right questions in the right way: the need for a shift in research on psychological treatments for addiction.

    PubMed

    Orford, Jim

    2008-06-01

    To identify possible reasons for the disappointingly negative results of methodologically rigorous controlled trials of psychological treatments in the addictions field. A selective overview of the literature on addictive behaviour change. Eight failings of existing research are described: failing to account for the outcome equivalence paradox; neglecting relationships in favour of techniques; failing to integrate treatment research and research on unaided change; imposing an inappropriate time-scale on the change process; failing to take a systems or social network view; ignoring therapists' tacit theories; not including the patient's view; and displaying an ignorance of modern developments in the philosophy of science. Treatment research has been asking the wrong questions in the wrong way. Three necessary shifts in ways of conducting research are proposed: (i) the field should stop studying named techniques and focus instead on change processes; (ii) change processes should be studied within the broader, longer-acting systems of which treatment is part; and (iii) science in the field should be brought up to date by acknowledging a variety of sources of useful knowledge.

  3. Rift systems in the southern North Atlantic: why did some fail and others not?

    NASA Astrophysics Data System (ADS)

    Nirrengarten, M.; Manatschal, G.; Tugend, J.; Kusznir, N. J.; Sauter, D.

    2017-12-01

    Orphan, Rockall, Porcupine, Parentis and Pyrenean Basins are failed rift systems surrounding the southern North Atlantic Ocean. The failure or succeessing of a rift system is intimately linked to the question of what controls lithospheric breakup and what keeps oceanic spreading alive. Extension rates and the thermal structure are usually the main parameters invoked. However, between the rifts that succeeded and those that failed, the relative control and relative importance of these parameters is not clear. Cessation of driving forces, strain hardening or competition between concurrent rifts are hypotheses often used to explain rift failure. In this work, we aim to analyze the influence of far field forces on the abandon of rift systems in the southern North Atlantic domain using plate kinematic modeling. A new reconstruction approach that integrates the spatio-temporal evolution of rifted basins has been developed. The plate modeling is based on the definition, mapping and restoration of rift domains using 3D gravity inversions methods that provide crustal thickness maps. The kinematic description of each rift system enables us to discuss the local rift evolution relative to the far field kinematic framework. The resulting model shows a strong segmentation of the different rift systems during extreme crustal thinning that are crosscut by V-shape propagators linked to the exhumation of mantle and emplacement of first oceanic crust. The northward propagating lithospheric breakup of the southern North Atlantic may be partly triggered and channeled by extreme lithospheric thinning. However, at Aptian-Albian time, the northward propagating lithospheric breakup diverts and is partitioned along a transtensional system resulting in the abandon of the Orphan and Rockall basins. The change in the propagation direction may be related to a local strain weakening along existing/inherited transfer zones and/or, alternatively, to a more global plate reorganization. The cessation of the Bay of Biscay-Pyrenean system is related to the northward motion of Africa at Campanian/Santonian time, resulting in a competition between incipient seafloor spreading and far field forces. A concordance between far field forces, lithospheric architecture and strain weakening seems necessary to create a sustainable oceanic domain.

  4. Design of a Geothermal Downhole Magnetic Flowmeter

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

    Glowka, Dave A.; Normann, Randy A.

    2015-06-15

    This paper covers the development of a 300°C geothermal solid-state magnetic flowmeter (or magmeter) to support in situ monitoring of future EGS (enhanced geothermal system) production wells. Existing flowmeters are simple mechanical spinner sensors. These mechanical sensors fail within as little as 10 hrs, while a solid-state magmeter has the potential for months/years of operation. The design and testing of a magnetic flow sensor for use with existing high-temperature electronics is presented.

  5. Response to Intervention: Ready or Not? Or, from Wait-to-Fail to Watch-Them-Fail

    ERIC Educational Resources Information Center

    Reynolds, Cecil R.; Shaywitz, Sally E.

    2009-01-01

    Response to Intervention (RTI) models of diagnosis and intervention are being implemented rapidly throughout the schools. The purposes of invoking an RTI model for disabilities in the schools clearly are laudable, yet close examination reveals an unappreciated paucity of empirical support for RTI and an overly optimistic view of its practical,…

  6. Improving the Enterprise Requirements and Acquisition Model’s Developmental Test and Evaluation Process Fidelity

    DTIC Science & Technology

    2014-03-27

    and excluded from the model. The “Check SVR Loop” prevents programs from failing the SVR a second time. If a program has not previously failed the SVR...and Acquisition Management Plan Initiative. Briefing, Peterson AFB, CO: HQ AFSPC/A5X, 2011. Gilmore, Michael J., Key Issues Causing Prgram Delays

  7. Survival Predictions of Ceramic Crowns Using Statistical Fracture Mechanics

    PubMed Central

    Nasrin, S.; Katsube, N.; Seghi, R.R.; Rokhlin, S.I.

    2017-01-01

    This work establishes a survival probability methodology for interface-initiated fatigue failures of monolithic ceramic crowns under simulated masticatory loading. A complete 3-dimensional (3D) finite element analysis model of a minimally reduced molar crown was developed using commercially available hardware and software. Estimates of material surface flaw distributions and fatigue parameters for 3 reinforced glass-ceramics (fluormica [FM], leucite [LR], and lithium disilicate [LD]) and a dense sintered yttrium-stabilized zirconia (YZ) were obtained from the literature and incorporated into the model. Utilizing the proposed fracture mechanics–based model, crown survival probability as a function of loading cycles was obtained from simulations performed on the 4 ceramic materials utilizing identical crown geometries and loading conditions. The weaker ceramic materials (FM and LR) resulted in lower survival rates than the more recently developed higher-strength ceramic materials (LD and YZ). The simulated 10-y survival rate of crowns fabricated from YZ was only slightly better than those fabricated from LD. In addition, 2 of the model crown systems (FM and LD) were expanded to determine regional-dependent failure probabilities. This analysis predicted that the LD-based crowns were more likely to fail from fractures initiating from margin areas, whereas the FM-based crowns showed a slightly higher probability of failure from fractures initiating from the occlusal table below the contact areas. These 2 predicted fracture initiation locations have some agreement with reported fractographic analyses of failed crowns. In this model, we considered the maximum tensile stress tangential to the interfacial surface, as opposed to the more universally reported maximum principal stress, because it more directly impacts crack propagation. While the accuracy of these predictions needs to be experimentally verified, the model can provide a fundamental understanding of the importance that pre-existing flaws at the intaglio surface have on fatigue failures. PMID:28107637

  8. Compton thick absorber in type 1 quasar 3C 345 revealed by Suzaku and Swift/BAT

    NASA Astrophysics Data System (ADS)

    Eguchi, Satoshi

    2017-07-01

    The archival data of 3C 345, a type 1 quasar at z = 0.5928, obtained with Suzaku and Swift/BAT are analysed. Though previous studies of this source applied only a simple broken power-law model, a heavily obscuring material is found to be required by considering Akaike information criteria. The application of the numerical torus model by Murphy & Yaqoob surprisingly reveals the existence of Compton thick type 2 nucleus with the line-of-sight hydrogen column density of the torus of NH = 1024.5 cm-2 and the inclination angle of θinc = 90°. However, this model fails to account for the Eddington ratio obtained with the optical observations by Gu et al. and Shen et al., or requires the existence of a supermassive black hole binary, which was suggested by Lobanov & Roland, thus this model is likely to be inappropriate for 3C 345. A partial covering ionized absorber model that accounts for absorption in 'hard excess' type 1 active galactic nuclei (AGNs) is also applied, and finds a Compton thick absorber with the column density of NH ≃ 1025 cm-2, the ionization parameter of log ξ ≳ 2 and the covering fraction of 75 per cent ≲ fc ≲ 85 per cent. Since this model obtains a black hole mass of log (MBH/M⊙) = 9.8, which is consistent with the optical observation by Gu et al., this model is likely to be the best-fitting model of this source. The results suggest that 3C 345 is the most distant and most obscured hard excess AGN at this time.

  9. Validation of mathematical models for Salmonella growth in raw ground beef under dynamic temperature conditions representing loss of refrigeration.

    PubMed

    McConnell, Jennifer A; Schaffner, Donald W

    2014-07-01

    Temperature is a primary factor in controlling the growth of microorganisms in food. The current U. S. Food and Drug Administration Model Food Code guidelines state that food can be kept out of temperature control for up to 4 h without qualifiers, or up to 6 h, if the food product starts at an initial 41 °F (5 °C) temperature and does not exceed 70 °F (21 °C) at 6 h. This project validates existing ComBase computer models for Salmonella growth under changing temperature conditions modeling scenarios using raw ground beef as a model system. A cocktail of Salmonella serovars isolated from different meat products ( Salmonella Copenhagen, Salmonella Montevideo, Salmonella Typhimurium, Salmonella Saintpaul, and Salmonella Heidelberg) was made rifampin resistant and used for all experiments. Inoculated samples were held in a programmable water bath at 4.4 °C (40 °F) and subjected to linear temperature changes to different final temperatures over various lengths of time and then returned to 4.4 °C (40 °F). Maximum temperatures reached were 15.6, 26.7, or 37.8 °C (60, 80, or 100 °F), and the temperature increases took place over 4, 6, and 8 h, with varying cooling times. Our experiments show that when maximum temperatures were lower (15.6 or 26.7 °C), there was generally good agreement between the ComBase models and experiments: when temperature increases of 15.6 or 26.7 °C occurred over 8 h, experimental data were within 0.13 log CFU of the model predictions. When maximum temperatures were 37 °C, predictive models were fail-safe. Overall bias of the models was 1.11. and accuracy was 2.11. Our experiments show the U.S. Food and Drug Administration Model Food Code guidelines for holding food out of temperature control are quite conservative. Our research also shows that the ComBase models for Salmonella growth are accurate or fail-safe for dynamic temperature conditions as might be observed due to power loss from natural disasters or during transport out of temperature control.

  10. Eating disorders among fashion models: a systematic review of the literature.

    PubMed

    Zancu, Simona Alexandra; Enea, Violeta

    2017-09-01

    In the light of recent concerns regarding the eating disorders among fashion models and professional regulations of fashion model occupation, an examination of the scientific evidence on this issue is necessary. The article reviews findings on the prevalence of eating disorders and body image concerns among professional fashion models. A systematic literature search was conducted using ProQUEST, EBSCO, PsycINFO, SCOPUS, and Gale Canage electronic databases. A very low number of studies conducted on fashion models and eating disorders resulted between 1980 and 2015, with seven articles included in this review. Overall, results of these studies do not indicate a higher prevalence of eating disorders among fashion models compared to non-models. Fashion models have a positive body image and generally do not report more dysfunctional eating behaviors than controls. However, fashion models are on average slightly underweight with significantly lower BMI than controls, and give higher importance to appearance and thin body shape, and thus have a higher prevalence of partial-syndrome eating disorders than controls. Despite public concerns, research on eating disorders among professional fashion models is extremely scarce and results cannot be generalized to all models. The existing research fails to clarify the matter of eating disorders among fashion models and given the small number of studies, further research is needed.

  11. Advancements in engineering turbulence modeling

    NASA Technical Reports Server (NTRS)

    Shih, T.-H.

    1991-01-01

    Some new developments in two-equation models and second order closure models are presented. Two-equation models (k-epsilon models) have been widely used in computational fluid dynamics (CFD) for engineering problems. Most of low-Reynolds number two-equation models contain some wall-distance damping functions to account for the effect of wall on turbulence. However, this often causes the confusion and difficulties in computing flows with complex geometry and also needs an ad hoc treatment near the separation and reattachment points. A set of modified two-equation models is proposed to remove the aforementioned shortcomings. The calculations using various two-equation models are compared with direct numerical simulations of channel flow and flat boundary layers. Development of a second order closure model is also discussed with emphasis on the modeling of pressure related correlation terms and dissipation rates in the second moment equations. All the existing models poorly predict the normal stresses near the wall and fail to predict the 3-D effect of mean flow on the turbulence (e.g. decrease in the shear stress caused by the cross flow in the boundary layer). The newly developed second order near-wall turbulence model is described and is capable of capturing the near-wall behavior of turbulence as well as the effect of 3-D mean flow on the turbulence.

  12. Using a business model approach and marketing techniques for recruitment to clinical trials

    PubMed Central

    2011-01-01

    Randomised controlled trials (RCTs) are generally regarded as the gold standard for evaluating health care interventions. The level of uncertainty around a trial's estimate of effect is, however, frequently linked to how successful the trial has been in recruiting and retaining participants. As recruitment is often slower or more difficult than expected, with many trials failing to reach their target sample size within the timescale and funding originally envisaged, the results are often less reliable than they could have been. The high number of trials that require an extension to the recruitment period in order to reach the required sample size potentially delays the introduction of more effective therapies into routine clinical practice. Moreover, it may result in less research being undertaken as resources are redirected to extending existing trials rather than funding additional studies. Poor recruitment to publicly-funded RCTs has been much debated but there remains remarkably little clear evidence as to why many trials fail to recruit well, which recruitment methods work, in which populations and settings and for what type of intervention. One proposed solution to improving recruitment and retention is to adopt methodology from the business world to inform and structure trial management techniques. We review what is known about interventions to improve recruitment to trials. We describe a proposed business approach to trials and discuss the implementation of using a business model, using insights gained from three case studies. PMID:21396088

  13. Using a business model approach and marketing techniques for recruitment to clinical trials.

    PubMed

    McDonald, Alison M; Treweek, Shaun; Shakur, Haleema; Free, Caroline; Knight, Rosemary; Speed, Chris; Campbell, Marion K

    2011-03-11

    Randomised controlled trials (RCTs) are generally regarded as the gold standard for evaluating health care interventions. The level of uncertainty around a trial's estimate of effect is, however, frequently linked to how successful the trial has been in recruiting and retaining participants. As recruitment is often slower or more difficult than expected, with many trials failing to reach their target sample size within the timescale and funding originally envisaged, the results are often less reliable than they could have been. The high number of trials that require an extension to the recruitment period in order to reach the required sample size potentially delays the introduction of more effective therapies into routine clinical practice. Moreover, it may result in less research being undertaken as resources are redirected to extending existing trials rather than funding additional studies.Poor recruitment to publicly-funded RCTs has been much debated but there remains remarkably little clear evidence as to why many trials fail to recruit well, which recruitment methods work, in which populations and settings and for what type of intervention. One proposed solution to improving recruitment and retention is to adopt methodology from the business world to inform and structure trial management techniques.We review what is known about interventions to improve recruitment to trials. We describe a proposed business approach to trials and discuss the implementation of using a business model, using insights gained from three case studies.

  14. Why fruit rots: theoretical support for Janzen's theory of microbe-macrobe competition.

    PubMed

    Ruxton, Graeme D; Wilkinson, David M; Schaefer, H Martin; Sherratt, Thomas N

    2014-05-07

    We present a formal model of Janzen's influential theory that competition for resources between microbes and vertebrates causes microbes to be selected to make these resources unpalatable to vertebrates. That is, fruit rots, seeds mould and meat spoils, in part, because microbes gain a selective advantage if they can alter the properties of these resources to avoid losing the resources to vertebrate consumers. A previous model had failed to find circumstances in which such a costly spoilage trait could flourish; here, we present a simple analytic model of a general situation where costly microbial spoilage is selected and persists. We argue that the key difference between the two models lies in their treatments of microbial dispersal. If microbial dispersal is sufficiently spatially constrained that different resource items can have differing microbial communities, then spoilage will be selected; however, if microbial dispersal has a strong homogenizing effect on the microbial community then spoilage will not be selected. We suspect that both regimes will exist in the natural world, and suggest how future empirical studies could explore the influence of microbial dispersal on spoilage.

  15. A modified NSGA-II solution for a new multi-objective hub maximal covering problem under uncertain shipments

    NASA Astrophysics Data System (ADS)

    Ebrahimi Zade, Amir; Sadegheih, Ahmad; Lotfi, Mohammad Mehdi

    2014-07-01

    Hubs are centers for collection, rearrangement, and redistribution of commodities in transportation networks. In this paper, non-linear multi-objective formulations for single and multiple allocation hub maximal covering problems as well as the linearized versions are proposed. The formulations substantially mitigate complexity of the existing models due to the fewer number of constraints and variables. Also, uncertain shipments are studied in the context of hub maximal covering problems. In many real-world applications, any link on the path from origin to destination may fail to work due to disruption. Therefore, in the proposed bi-objective model, maximizing safety of the weakest path in the network is considered as the second objective together with the traditional maximum coverage goal. Furthermore, to solve the bi-objective model, a modified version of NSGA-II with a new dynamic immigration operator is developed in which the accurate number of immigrants depends on the results of the other two common NSGA-II operators, i.e. mutation and crossover. Besides validating proposed models, computational results confirm a better performance of modified NSGA-II versus traditional one.

  16. Model selection for marginal regression analysis of longitudinal data with missing observations and covariate measurement error.

    PubMed

    Shen, Chung-Wei; Chen, Yi-Hau

    2015-10-01

    Missing observations and covariate measurement error commonly arise in longitudinal data. However, existing methods for model selection in marginal regression analysis of longitudinal data fail to address the potential bias resulting from these issues. To tackle this problem, we propose a new model selection criterion, the Generalized Longitudinal Information Criterion, which is based on an approximately unbiased estimator for the expected quadratic error of a considered marginal model accounting for both data missingness and covariate measurement error. The simulation results reveal that the proposed method performs quite well in the presence of missing data and covariate measurement error. On the contrary, the naive procedures without taking care of such complexity in data may perform quite poorly. The proposed method is applied to data from the Taiwan Longitudinal Study on Aging to assess the relationship of depression with health and social status in the elderly, accommodating measurement error in the covariate as well as missing observations. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. A discrete mechanics framework for real time virtual surgical simulations with application to virtual laparoscopic nephrectomy.

    PubMed

    Zhou, Xiangmin; Zhang, Nan; Sha, Desong; Shen, Yunhe; Tamma, Kumar K; Sweet, Robert

    2009-01-01

    The inability to render realistic soft-tissue behavior in real time has remained a barrier to face and content aspects of validity for many virtual reality surgical training systems. Biophysically based models are not only suitable for training purposes but also for patient-specific clinical applications, physiological modeling and surgical planning. When considering the existing approaches for modeling soft tissue for virtual reality surgical simulation, the computer graphics-based approach lacks predictive capability; the mass-spring model (MSM) based approach lacks biophysically realistic soft-tissue dynamic behavior; and the finite element method (FEM) approaches fail to meet the real-time requirement. The present development stems from physics fundamental thermodynamic first law; for a space discrete dynamic system directly formulates the space discrete but time continuous governing equation with embedded material constitutive relation and results in a discrete mechanics framework which possesses a unique balance between the computational efforts and the physically realistic soft-tissue dynamic behavior. We describe the development of the discrete mechanics framework with focused attention towards a virtual laparoscopic nephrectomy application.

  18. 45 CFR 672.7 - Issuance of complaint.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ENFORCEMENT AND... permittee misrepresented or inaccurately described any material fact in the permit application or failed to disclose all relevant facts in the permit application, or (3) other good cause exists for such action, he...

  19. 45 CFR 672.7 - Issuance of complaint.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ENFORCEMENT AND... permittee misrepresented or inaccurately described any material fact in the permit application or failed to disclose all relevant facts in the permit application, or (3) other good cause exists for such action, he...

  20. 45 CFR 672.7 - Issuance of complaint.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ENFORCEMENT AND... permittee misrepresented or inaccurately described any material fact in the permit application or failed to disclose all relevant facts in the permit application, or (3) other good cause exists for such action, he...

  1. 45 CFR 672.7 - Issuance of complaint.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ENFORCEMENT AND... permittee misrepresented or inaccurately described any material fact in the permit application or failed to disclose all relevant facts in the permit application, or (3) other good cause exists for such action, he...

  2. 45 CFR 672.7 - Issuance of complaint.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ENFORCEMENT AND... permittee misrepresented or inaccurately described any material fact in the permit application or failed to disclose all relevant facts in the permit application, or (3) other good cause exists for such action, he...

  3. Lotka-Volterra pairwise modeling fails to capture diverse pairwise microbial interactions

    PubMed Central

    Momeni, Babak; Xie, Li; Shou, Wenying

    2017-01-01

    Pairwise models are commonly used to describe many-species communities. In these models, an individual receives additive fitness effects from pairwise interactions with each species in the community ('additivity assumption'). All pairwise interactions are typically represented by a single equation where parameters reflect signs and strengths of fitness effects ('universality assumption'). Here, we show that a single equation fails to qualitatively capture diverse pairwise microbial interactions. We build mechanistic reference models for two microbial species engaging in commonly-found chemical-mediated interactions, and attempt to derive pairwise models. Different equations are appropriate depending on whether a mediator is consumable or reusable, whether an interaction is mediated by one or more mediators, and sometimes even on quantitative details of the community (e.g. relative fitness of the two species, initial conditions). Our results, combined with potential violation of the additivity assumption in many-species communities, suggest that pairwise modeling will often fail to predict microbial dynamics. DOI: http://dx.doi.org/10.7554/eLife.25051.001 PMID:28350295

  4. Notes and comments "High and dry?" The Public Readiness and Emergency Preparedness Act and liability protection for pharmaceutical manufacturers.

    PubMed

    Copper, B Kurt

    2007-01-01

    In an era filled with fears of bioterrorism, Congress approved the Public Readiness and Emergency Preparedness Act (PREPA) to encourage development of vaccines and other countermeasures. By providing pharmaceutical manufacturers with protection from liability for potential side effects, Congress has attempted to motivate manufacturers to produce a national stockpile of countermeasures. As part of PREPA, the government established a compensatory system intended to provide compensation to persons injured by countermeasures used during a public health emergency. Although the Act provides for a compensation fund, it fails to allocate monies for that fund. Thus, in the absence of further congressional action, PREPA will not provide compensation to those injured by countermeasures. Failing to assure the American public of a compensation program constitutes bad public policy and risks inspiring potential vaccinees to refuse necessary drugs. Additionally, arguments as to the constitutionality of the Act exist should Congress fail to adequately fund the program, and the existence of those arguments undermines the purpose of the Act--namely to assure pharmaceutical manufacturers that they will not be sued into oblivion should they attempt to aid national pandemic protection. In addition to detailing both the Act and the statutory precedent for congressional attempts to spur biodefense, this Article addresses important issues of healthcare, tort, and constitutional law that will continue to manifest themselves in this new era of bioterrorism.

  5. Upscaling Bedrock Erosion Laws from the Point to the Patch and from the Event to the Year

    NASA Astrophysics Data System (ADS)

    Beer, A. R.; Turowski, J. M.

    2017-12-01

    Bedrock erosion depends on the interactions between the bedload tools and cover effects. However, it is unclear (i) how well long-term calibrations of existing erosion models can predict individual erosion events, and (ii) whether at-a-point event calibrations can be spatio-temporally upscaled. Here, we evaluate the performance of at-a-point calibrated erosion models by scaling their erosional efficiency coefficients (k-factors). We use continuous measurements of water discharge and bedload transport at 1- minute resolution, supplemented by repeated sub-millimeter-resolution spatial erosion surveys of a concrete slab in a small Swiss pre-alpine stream. Our results confirm the linear dependency of bedrock abrasion on sediment flux under sediment-starved conditions integrated over space (the 0.2m2 slab surface) and time (20 months). The predictive quality of the commonly applied unit stream power (USP) model is strongly susceptible to bedload transport distribution, whereas the bedload-dependent tools-only model yields more reasonable results. Applying the fitted mean model k-factors to a 16-year, 1-minute-resolution time series of discharge and bedload transport shows that the excess USP model EUSP (which includes a discharge threshold for bedload transport) generally predicts cumulative erosion reasonably well. For exceptional events, however, the EUSP model fails to predict the resulting large erosion rates. Hence, for sediment-starved conditions, event-based erosion model calibration can be applied over larger spatio-temporal scales with stationary k-factors, if a discharge threshold for sediment transport is taken into account. The EUSP model is a surrogate to predict long-term erosion given average erosive events, but fails to capture large event erosion rates. Consequently, the erosion tendency during average erosive events is generally matched by overall EUSP modelling, but large and highly erosive events are underpredicted. In such, water discharge does not account for the non-linearity in sediment availability (e.g., due to sudden release of interlocked sediment from the streambed) and in grain impact energies on the bedrock (i.e., large grain impacts dominate total erosion), which are the main drivers of a bedrock channel's morphology.

  6. 77 FR 26663 - Airworthiness Directives; The Boeing Company Model 767-200, -300, -300F, and -400ER Series Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-07

    ... removing corrosion from fail-safe straps. We have received Boeing Service Bulletin 767-53A0100, Revision 3.... That AD currently requires inspections to detect cracking or corrosion of the fail-safe straps between... cracks in 51 fail-safe straps on 41 airplanes; we have also received a report of a crack found in the ``T...

  7. Leadership Development: A Senior Leader Case Study

    DTIC Science & Technology

    2014-10-01

    LIFE model Element Investigative Question Strategy How does (development program) posture (or fail to posture ) leaders to meet organizational...Management How does (development program) adequately posture (or fail to posture ) officer talent capable of filling talent gaps within the...LIFE model in figure 1 stems from conceptualizing and integrat- ing elements of leadership development in the work of Stephen Co- hen , Lisa Gabel

  8. Technique for Early Reliability Prediction of Software Components Using Behaviour Models

    PubMed Central

    Ali, Awad; N. A. Jawawi, Dayang; Adham Isa, Mohd; Imran Babar, Muhammad

    2016-01-01

    Behaviour models are the most commonly used input for predicting the reliability of a software system at the early design stage. A component behaviour model reveals the structure and behaviour of the component during the execution of system-level functionalities. There are various challenges related to component reliability prediction at the early design stage based on behaviour models. For example, most of the current reliability techniques do not provide fine-grained sequential behaviour models of individual components and fail to consider the loop entry and exit points in the reliability computation. Moreover, some of the current techniques do not tackle the problem of operational data unavailability and the lack of analysis results that can be valuable for software architects at the early design stage. This paper proposes a reliability prediction technique that, pragmatically, synthesizes system behaviour in the form of a state machine, given a set of scenarios and corresponding constraints as input. The state machine is utilized as a base for generating the component-relevant operational data. The state machine is also used as a source for identifying the nodes and edges of a component probabilistic dependency graph (CPDG). Based on the CPDG, a stack-based algorithm is used to compute the reliability. The proposed technique is evaluated by a comparison with existing techniques and the application of sensitivity analysis to a robotic wheelchair system as a case study. The results indicate that the proposed technique is more relevant at the early design stage compared to existing works, and can provide a more realistic and meaningful prediction. PMID:27668748

  9. Mitochondrionopathy phenotype in doxorubicin-treated Wistar rats depends on treatment protocol and is cardiac-specific.

    PubMed

    Pereira, Gonçalo C; Pereira, Susana P; Pereira, Claudia V; Lumini, José A; Magalhães, José; Ascensão, António; Santos, Maria S; Moreno, António J; Oliveira, Paulo J

    2012-01-01

    Although doxorubicin (DOX) is a very effective antineoplastic agent, its clinical use is limited by a dose-dependent, persistent and cumulative cardiotoxicity, whose mechanism remains to be elucidated. Previous works in animal models have failed to use a multi-organ approach to demonstrate that DOX-associated toxicity is selective to the cardiac tissue. In this context, the present work aims to investigate in vivo DOX cardiac, hepatic and renal toxicity in the same animal model, with special relevance on alterations of mitochondrial bioenergetics. To this end, male Wistar rats were sub-chronically (7 wks, 2 mg/Kg) or acutely (20 mg/Kg) treated with DOX and sacrificed one week or 24 hours after the last injection, respectively. Alterations of mitochondrial bioenergetics showed treatment-dependent differences between tissues. No alterations were observed for cardiac mitochondria in the acute model but decreased ADP-stimulated respiration was detected in the sub-chronic treatment. In the acute treatment model, ADP-stimulated respiration was increased in liver and decreased in kidney mitochondria. Aconitase activity, a marker of oxidative stress, was decreased in renal mitochondria in the acute and in heart in the sub-chronic model. Interestingly, alterations of cardiac mitochondrial bioenergetics co-existed with an absence of echocardiograph, histopathological or ultra-structural alterations. Besides, no plasma markers of cardiac injury were found in any of the time points studied. The results confirm that alterations of mitochondrial function, which are more evident in the heart, are an early marker of DOX-induced toxicity, existing even in the absence of cardiac functional alterations.

  10. Mitochondrionopathy Phenotype in Doxorubicin-Treated Wistar Rats Depends on Treatment Protocol and Is Cardiac-Specific

    PubMed Central

    Pereira, Gonçalo C.; Pereira, Susana P.; Pereira, Claudia V.; Lumini, José A.; Magalhães, José; Ascensão, António; Santos, Maria S.; Moreno, António J.; Oliveira, Paulo J.

    2012-01-01

    Although doxorubicin (DOX) is a very effective antineoplastic agent, its clinical use is limited by a dose-dependent, persistent and cumulative cardiotoxicity, whose mechanism remains to be elucidated. Previous works in animal models have failed to use a multi-organ approach to demonstrate that DOX-associated toxicity is selective to the cardiac tissue. In this context, the present work aims to investigate in vivo DOX cardiac, hepatic and renal toxicity in the same animal model, with special relevance on alterations of mitochondrial bioenergetics. To this end, male Wistar rats were sub-chronically (7 wks, 2 mg/Kg) or acutely (20 mg/Kg) treated with DOX and sacrificed one week or 24 hours after the last injection, respectively. Alterations of mitochondrial bioenergetics showed treatment-dependent differences between tissues. No alterations were observed for cardiac mitochondria in the acute model but decreased ADP-stimulated respiration was detected in the sub-chronic treatment. In the acute treatment model, ADP-stimulated respiration was increased in liver and decreased in kidney mitochondria. Aconitase activity, a marker of oxidative stress, was decreased in renal mitochondria in the acute and in heart in the sub-chronic model. Interestingly, alterations of cardiac mitochondrial bioenergetics co-existed with an absence of echocardiograph, histopathological or ultra-structural alterations. Besides, no plasma markers of cardiac injury were found in any of the time points studied. The results confirm that alterations of mitochondrial function, which are more evident in the heart, are an early marker of DOX-induced toxicity, existing even in the absence of cardiac functional alterations. PMID:22745682

  11. Failure detection and identification

    NASA Technical Reports Server (NTRS)

    Massoumnia, Mohammad-Ali; Verghese, George C.; Willsky, Alan S.

    1989-01-01

    Using the geometric concept of an unobservability subspace, a solution is given to the problem of detecting and identifying control system component failures in linear, time-invariant systems. Conditions are developed for the existence of a causal, linear, time-invariant processor that can detect and uniquely identify a component failure, first for the case where components can fail simultaneously, and then for the case where they fail only one at a time. Explicit design algorithms are provided when these conditions are satisfied. In addition to time-domain solvability conditions, frequency-domain interpretations of the results are given, and connections are drawn with results already available in the literature.

  12. Supporting practice teachers to identify failing students.

    PubMed

    Skingley, Ann; Arnott, J; Greaves, J; Nabb, J

    2007-01-01

    The subject of identifying and supporting failing students in community nursing education programmes has been largely overlooked in the literature, yet is of great concern to practice teachers. This article discusses the views on the topic of a group of practice teachers in the light of existing, related research and proposes a number of indicators for good practice. It is suggested that of central importance is the need for higher education institutions and practice teachers to work together in identifying students causing concern at an early stage in their studies, based on both objective and subjective observations, and to have in place documented procedures to be followed when such situations arise.

  13. Longitudinal, label-free, quantitative tracking of cell death and viability in a 3D tumor model with OCT

    NASA Astrophysics Data System (ADS)

    Jung, Yookyung; Klein, Oliver J.; Wang, Hequn; Evans, Conor L.

    2016-06-01

    Three-dimensional in vitro tumor models are highly useful tools for studying tumor growth and treatment response of malignancies such as ovarian cancer. Existing viability and treatment assessment assays, however, face shortcomings when applied to these large, complex, and heterogeneous culture systems. Optical coherence tomography (OCT) is a noninvasive, label-free, optical imaging technique that can visualize live cells and tissues over time with subcellular resolution and millimeters of optical penetration depth. Here, we show that OCT is capable of carrying out high-content, longitudinal assays of 3D culture treatment response. We demonstrate the usage and capability of OCT for the dynamic monitoring of individual and combination therapeutic regimens in vitro, including both chemotherapy drugs and photodynamic therapy (PDT) for ovarian cancer. OCT was validated against the standard LIVE/DEAD Viability/Cytotoxicity Assay in small tumor spheroid cultures, showing excellent correlation with existing standards. Importantly, OCT was shown to be capable of evaluating 3D spheroid treatment response even when traditional viability assays failed. OCT 3D viability imaging revealed synergy between PDT and the standard-of-care chemotherapeutic carboplatin that evolved over time. We believe the efficacy and accuracy of OCT in vitro drug screening will greatly contribute to the field of cancer treatment and therapy evaluation.

  14. Marvels, mysteries, and misconceptions of vascular compensation to peripheral artery occlusion.

    PubMed

    Ziegler, Matthew A; Distasi, Matthew R; Bills, Randall G; Miller, Steven J; Alloosh, Mouhamad; Murphy, Michael P; Akingba, A George; Sturek, Michael; Dalsing, Michael C; Unthank, Joseph L

    2010-01-01

    Peripheral arterial disease is a major health problem and there is a significant need to develop therapies to prevent its progression to claudication and critical limb ischemia. Promising results in rodent models of arterial occlusion have generally failed to predict clinical success and led to questions of their relevance. While sub-optimal models may have contributed to the lack of progress, we suggest that advancement has also been hindered by misconceptions of the human capacity for compensation and the specific vessels which are of primary importance. We present and summarize new and existing data from humans, Ossabaw miniature pigs, and rodents which provide compelling evidence that natural compensation to occlusion of a major artery (i) may completely restore perfusion, (ii) occurs in specific pre-existing small arteries, rather than the distal vasculature, via mechanisms involving flow-mediated dilation and remodeling (iii) is impaired by cardiovascular risk factors which suppress the flow-mediated mechanisms and (iv) can be restored by reversal of endothelial dysfunction. We propose that restoration of the capacity for flow-mediated dilation and remodeling in small arteries represents a largely unexplored potential therapeutic opportunity to enhance compensation for major arterial occlusion and prevent the progression to critical limb ischemia in the peripheral circulation.

  15. Marvels, Mysteries, and Misconceptions of Vascular Compensation to Peripheral Artery Occlusion

    PubMed Central

    ZIEGLER, MATTHEW A.; DISTASI, MATTHEW R.; BILLS, RANDALL G.; MILLER, STEVEN J.; ALLOOSH, MOUHAMAD; MURPHY, MICHAEL P.; AKINGBA, A. GEORGE; STUREK, MICHAEL; DALSING, MICHAEL C.; UNTHANK, JOSEPH L.

    2010-01-01

    Peripheral arterial disease is a major health problem and there is a significant need to develop therapies to prevent its progression to claudication and critical limb ischemia. Promising results in rodent models of arterial occlusion have generally failed to predict clinical success and led to questions of their relevance. While sub-optimal models may have contributed to the lack of progress, we suggest that advancement has also been hindered by misconceptions of the human capacity for compensation and the specific vessels which are of primary importance. We present and summarize new and existing data from humans, Ossabaw miniature pigs, and rodents which provide compelling evidence that natural compensation to occlusion of a major artery (i) may completely restore perfusion, (ii) occurs in specific pre-existing small arteries, rather than the distal vasculature, via mechanisms involving flow-mediated dilation and remodeling (iii) is impaired by cardiovascular risk factors which suppress the flow-mediated mechanisms and (iv) can be restored by reversal of endothelial dysfunction. We propose that restoration of the capacity for flow-mediated dilation and remodeling in small arteries represents a largely unexplored potential therapeutic opportunity to enhance compensation for major arterial occlusion and prevent the progression to critical limb ischemia in the peripheral circulation. PMID:20141596

  16. General subspace learning with corrupted training data via graph embedding.

    PubMed

    Bao, Bing-Kun; Liu, Guangcan; Hong, Richang; Yan, Shuicheng; Xu, Changsheng

    2013-11-01

    We address the following subspace learning problem: supposing we are given a set of labeled, corrupted training data points, how to learn the underlying subspace, which contains three components: an intrinsic subspace that captures certain desired properties of a data set, a penalty subspace that fits the undesired properties of the data, and an error container that models the gross corruptions possibly existing in the data. Given a set of data points, these three components can be learned by solving a nuclear norm regularized optimization problem, which is convex and can be efficiently solved in polynomial time. Using the method as a tool, we propose a new discriminant analysis (i.e., supervised subspace learning) algorithm called Corruptions Tolerant Discriminant Analysis (CTDA), in which the intrinsic subspace is used to capture the features with high within-class similarity, the penalty subspace takes the role of modeling the undesired features with high between-class similarity, and the error container takes charge of fitting the possible corruptions in the data. We show that CTDA can well handle the gross corruptions possibly existing in the training data, whereas previous linear discriminant analysis algorithms arguably fail in such a setting. Extensive experiments conducted on two benchmark human face data sets and one object recognition data set show that CTDA outperforms the related algorithms.

  17. Joint Facial Action Unit Detection and Feature Fusion: A Multi-conditional Learning Approach.

    PubMed

    Eleftheriadis, Stefanos; Rudovic, Ognjen; Pantic, Maja

    2016-10-05

    Automated analysis of facial expressions can benefit many domains, from marketing to clinical diagnosis of neurodevelopmental disorders. Facial expressions are typically encoded as a combination of facial muscle activations, i.e., action units. Depending on context, these action units co-occur in specific patterns, and rarely in isolation. Yet, most existing methods for automatic action unit detection fail to exploit dependencies among them, and the corresponding facial features. To address this, we propose a novel multi-conditional latent variable model for simultaneous fusion of facial features and joint action unit detection. Specifically, the proposed model performs feature fusion in a generative fashion via a low-dimensional shared subspace, while simultaneously performing action unit detection using a discriminative classification approach. We show that by combining the merits of both approaches, the proposed methodology outperforms existing purely discriminative/generative methods for the target task. To reduce the number of parameters, and avoid overfitting, a novel Bayesian learning approach based on Monte Carlo sampling is proposed, to integrate out the shared subspace. We validate the proposed method on posed and spontaneous data from three publicly available datasets (CK+, DISFA and Shoulder-pain), and show that both feature fusion and joint learning of action units leads to improved performance compared to the state-of-the-art methods for the task.

  18. Toward High School Biology: Helping Middle School Students Understand Chemical Reactions and Conservation of Mass in Nonliving and Living Systems

    PubMed Central

    Herrmann-Abell, Cari F.; Koppal, Mary; Roseman, Jo Ellen

    2016-01-01

    Modern biology has become increasingly molecular in nature, requiring students to understand basic chemical concepts. Studies show, however, that many students fail to grasp ideas about atom rearrangement and conservation during chemical reactions or the application of these ideas to biological systems. To help provide students with a better foundation, we used research-based design principles and collaborated in the development of a curricular intervention that applies chemistry ideas to living and nonliving contexts. Six eighth grade teachers and their students participated in a test of the unit during the Spring of 2013. Two of the teachers had used an earlier version of the unit the previous spring. The other four teachers were randomly assigned either to implement the unit or to continue teaching the same content using existing materials. Pre- and posttests were administered, and the data were analyzed using Rasch modeling and hierarchical linear modeling. The results showed that, when controlling for pretest score, gender, language, and ethnicity, students who used the curricular intervention performed better on the posttest than the students using existing materials. Additionally, students who participated in the intervention held fewer misconceptions. These results demonstrate the unit’s promise in improving students’ understanding of the targeted ideas. PMID:27909024

  19. Using Molecular Dynamics to quantify the electrical double layer and examine the potential for its direct observation in the in-situ TEM

    DOE PAGES

    Welch, David A.; Mehdi, Beata L.; Hatchell, Hanna J.; ...

    2015-03-25

    Understanding the fundamental processes taking place at the electrode-electrolyte interface in batteries will play a key role in the development of next generation energy storage technologies. One of the most fundamental aspects of the electrode-electrolyte interface is the electrical double layer (EDL). Given the recent development of high spatial resolution in-situ electrochemical cells for scanning transmission electron microscopy (STEM), there now exists the possibility that we can directly observe the formation and dynamics of the EDL. In this paper we predict electrolyte structure within the EDL using classical models and atomistic Molecular Dynamics (MD) simulations. The MD simulations show thatmore » the classical models fail to accurately reproduce concentration profiles that exist within the electrolyte. It is thus suggested that MD must be used in order to accurately predict STEM images of the electrode-electrolyte interface. Using MD and image simulations together for a high contrast electrolyte (the high atomic number CsCl electrolyte), it is determined that, for a smooth interface, concentration profiles within the EDL should be visible experimentally. When normal experimental parameters such as rough interfaces and low-Z electrolytes (like those used in Li-ion batteries) are considered, observation of the EDL appears to be more difficult.« less

  20. Reference Specimen for Nondestructive Evaluation: Characterization of the Oxide Layer of a Cold Shot in Inconel 600

    NASA Astrophysics Data System (ADS)

    Saletes, I.; Filleter, T.; Goldbaum, D.; Chromik, R. R.; Sinclair, A. N.

    2015-02-01

    The presence of a cold shot in an aircraft turbine blade can lead to the catastrophic failure of the blade and ultimately to the failure of the power plant. Currently, no nondestructive evaluation (NDE) method exists to detect this kind of defect. This deficiency is primarily due to the fact that the only known cold shot defects in existence are those found in failed blades. Therefore, in order to develop effective NDE methods, reference specimens are needed which mimic the embedded oxide layer that is a primary distinguishing feature of a cold shot. Here, we present a procedure to synthetically reproduce the features of a real cold shot in Inconel 600 and the precise characterization of this oxide layer as a reference specimen suitable for NDE evaluation. As a first step to develop a suitable NDE technique, high-frequency ultrasound simulations are considered. A theoretical 1-D model is developed in order to quantify the multiple reflection-transmission trajectory of the acoustic wave in the reference specimen. This paper also presents an experimental determination of the density and the Young's modulus of the Inconel 600 oxide, which are required as inputs to calculate the acoustic impedance used in the theoretical model.

  1. Inversion of Surface-wave Dispersion Curves due to Low-velocity-layer Models

    NASA Astrophysics Data System (ADS)

    Shen, C.; Xia, J.; Mi, B.

    2016-12-01

    A successful inversion relies on exact forward modeling methods. It is a key step to accurately calculate multi-mode dispersion curves of a given model in high-frequency surface-wave (Rayleigh wave and Love wave) methods. For normal models (shear (S)-wave velocity increasing with depth), their theoretical dispersion curves completely match the dispersion spectrum that is generated based on wave equation. For models containing a low-velocity-layer, however, phase velocities calculated by existing forward-modeling algorithms (e.g. Thomson-Haskell algorithm, Knopoff algorithm, fast vector-transfer algorithm and so on) fail to be consistent with the dispersion spectrum at a high frequency range. They will approach a value that close to the surface-wave velocity of the low-velocity-layer under the surface layer, rather than that of the surface layer when their corresponding wavelengths are short enough. This phenomenon conflicts with the characteristics of surface waves, which results in an erroneous inverted model. By comparing the theoretical dispersion curves with simulated dispersion energy, we proposed a direct and essential solution to accurately compute surface-wave phase velocities due to low-velocity-layer models. Based on the proposed forward modeling technique, we can achieve correct inversion for these types of models. Several synthetic data proved the effectiveness of our method.

  2. Evaluation of levee setbacks for flood-loss reduction, Middle Mississippi River, USA

    NASA Astrophysics Data System (ADS)

    Dierauer, Jennifer; Pinter, Nicholas; Remo, Jonathan W. F.

    2012-07-01

    SummaryOne-dimensional hydraulic modeling and flood-loss modeling were used to test the effectiveness of levee setbacks for flood-loss reduction along the Middle Mississippi River (MMR). Four levee scenarios were assessed: (1) the present-day levee configuration, (2) a 1000 m levee setback, (3) a 1500 m levee setback, and (4) an optimized setback configuration. Flood losses were estimated using FEMA's Hazus-MH (Hazards US Multi-Hazard) loss-estimation software on a structure-by-structure basis for a range of floods from the 2- to the 500-year events. These flood-loss estimates were combined with a levee-reliability model to calculate probability-weighted damage estimates. In the simplest case, the levee setback scenarios tested here reduced flood losses compared to current conditions for large, infrequent flooding events but increased flood losses for smaller, more frequent flood events. These increases occurred because levee protection was removed for some of the existing structures. When combined with buyouts of unprotected structures, levee setbacks reduced flood losses for all recurrence intervals. The "optimized" levee setback scenario, involving a levee configuration manually planned to protect existing high-value infrastructure, reduced damages with or without buyouts. This research shows that levee setbacks in combination with buyouts are an economically viable approach for flood-risk reduction along the study reach and likely elsewhere where levees are widely employed for flood control. Designing a levee setback around existing high-value infrastructure can maximize the benefit of the setback while simultaneously minimizing the costs. The optimized levee setback scenario analyzed here produced payback periods (costs divided by benefits) of less than 12 years. With many aging levees failing current inspections across the US, and flood losses spiraling up over time, levee setbacks are a viable solution for reducing flood exposure and flood levels.

  3. Awareness to Action.

    ERIC Educational Resources Information Center

    Blanzy, J.

    Macomb Community College in Michigan emphasized a commitment to economic development in an effort to combat a failing economy and falling resources for college funding. The college started by forming an internal task force to determine what alternatives were available to meet existing needs, then hosted two meetings focusing on economic…

  4. How To Make Innovations Practical

    ERIC Educational Resources Information Center

    Janssen, Fred; Westbroek, Hanna; Doyle, Walter; van Driel, Jan

    2013-01-01

    Background/Context: A fundamental tension has long existed between school reform proposals and actual teaching practice. Despite a large literature on teacher change, the discontinuity between innovation and practice continues and many attempts to reform teaching fail to be enacted in most classrooms. Purpose/Objective/Research Question/Focus of…

  5. Confronting Counsels of Despair for the Behavioral Sciences.

    ERIC Educational Resources Information Center

    Gage, N. L.

    1996-01-01

    Summarizes and challenges criticism that the behavioral sciences have failed to produce long-lasting generalizations due to cultural and historical relativism and interaction effects. Using findings from meta-analysis, the author argues that considerable consistency and validity across contexts of many generalizations exists, as well as promising…

  6. 46 CFR 28.880 - Hydraulic equipment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... times the system's maximum operating pressure. (c) Each hydraulic system must be equipped with at least... sudden loss of control due to loss of hydraulic system pressure. A system is considered to be fail-safe... catalog number and maximum allowable working pressure. (k) Existing hydraulic piping, nonmetallic hose...

  7. 46 CFR 28.880 - Hydraulic equipment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... times the system's maximum operating pressure. (c) Each hydraulic system must be equipped with at least... sudden loss of control due to loss of hydraulic system pressure. A system is considered to be fail-safe... catalog number and maximum allowable working pressure. (k) Existing hydraulic piping, nonmetallic hose...

  8. 46 CFR 28.880 - Hydraulic equipment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... times the system's maximum operating pressure. (c) Each hydraulic system must be equipped with at least... sudden loss of control due to loss of hydraulic system pressure. A system is considered to be fail-safe... catalog number and maximum allowable working pressure. (k) Existing hydraulic piping, nonmetallic hose...

  9. 46 CFR 28.880 - Hydraulic equipment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... times the system's maximum operating pressure. (c) Each hydraulic system must be equipped with at least... sudden loss of control due to loss of hydraulic system pressure. A system is considered to be fail-safe... catalog number and maximum allowable working pressure. (k) Existing hydraulic piping, nonmetallic hose...

  10. 45 CFR 2553.109 - What happens if a sponsor fails to meet the performance measures included in the Notice of Grant...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... target performance measure established in the NGA, the Corporation will negotiate a period of no more... application from the organization for a new grant or augmentation of an existing grant under any program...

  11. 45 CFR 2553.109 - What happens if a sponsor fails to meet the performance measures included in the Notice of Grant...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... target performance measure established in the NGA, the Corporation will negotiate a period of no more... application from the organization for a new grant or augmentation of an existing grant under any program...

  12. 45 CFR 86.4 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 86.4... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 86.3(a) to eliminate existing discrimination on the basis of sex or to...

  13. 22 CFR 229.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION... fails to commit itself to take whatever remedial action is necessary in accordance with § 229.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  14. 40 CFR 5.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 5.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  15. 34 CFR 106.4 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... or recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 106.3(a) to eliminate existing discrimination on the basis of sex...

  16. 14 CFR § 1253.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction... such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 1253.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the...

  17. 14 CFR 1253.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 1253... such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 1253.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the...

  18. 22 CFR 229.115 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION... fails to commit itself to take whatever remedial action is necessary in accordance with § 229.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  19. 14 CFR 1253.115 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 1253... such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 1253.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the...

  20. 6 CFR 17.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 17... such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 17.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the...

  1. 40 CFR 5.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 5.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  2. 45 CFR 618.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 618.110(a) to eliminate existing discrimination on the basis of sex or to...

  3. 6 CFR 17.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 17... such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 17.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the...

  4. 45 CFR 86.4 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 86.4... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 86.3(a) to eliminate existing discrimination on the basis of sex or to...

  5. 31 CFR 28.115 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 28... such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 28.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the...

  6. 34 CFR 106.4 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... or recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 106.3(a) to eliminate existing discrimination on the basis of sex...

  7. 31 CFR 28.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 28... such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 28.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the...

  8. 34 CFR 106.4 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... or recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 106.3(a) to eliminate existing discrimination on the basis of sex...

  9. 45 CFR 618.115 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 618.110(a) to eliminate existing discrimination on the basis of sex or to...

  10. 40 CFR 5.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 5.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  11. 6 CFR 17.115 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 17... such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 17.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the...

  12. 34 CFR 106.4 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... or recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 106.3(a) to eliminate existing discrimination on the basis of sex...

  13. 6 CFR 17.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 17... such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 17.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the...

  14. 28 CFR 54.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 54.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  15. 28 CFR 54.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 54.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  16. 28 CFR 54.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 54.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  17. 45 CFR 618.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 618.110(a) to eliminate existing discrimination on the basis of sex or to...

  18. 28 CFR 54.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 54.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  19. 45 CFR 618.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 618.110(a) to eliminate existing discrimination on the basis of sex or to...

  20. 31 CFR 28.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 28... such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 28.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the...

  1. 45 CFR 86.4 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 86.4... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 86.3(a) to eliminate existing discrimination on the basis of sex or to...

  2. 45 CFR 86.4 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 86.4... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 86.3(a) to eliminate existing discrimination on the basis of sex or to...

  3. 22 CFR 229.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION... fails to commit itself to take whatever remedial action is necessary in accordance with § 229.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  4. 45 CFR 86.4 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 86.4... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 86.3(a) to eliminate existing discrimination on the basis of sex or to...

  5. 31 CFR 28.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 28... such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 28.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the...

  6. 45 CFR 618.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 618.110(a) to eliminate existing discrimination on the basis of sex or to...

  7. 40 CFR 5.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 5.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  8. 31 CFR 28.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 28... such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 28.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the...

  9. 14 CFR 1253.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 1253... such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 1253.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the...

  10. 6 CFR 17.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 17... such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 17.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the...

  11. 22 CFR 229.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION... fails to commit itself to take whatever remedial action is necessary in accordance with § 229.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  12. 28 CFR 54.115 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 54.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  13. 40 CFR 5.115 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 5.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  14. 34 CFR 106.4 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... or recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 106.3(a) to eliminate existing discrimination on the basis of sex...

  15. 14 CFR 1253.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 1253... such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 1253.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the...

  16. 22 CFR 229.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION... fails to commit itself to take whatever remedial action is necessary in accordance with § 229.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  17. The Chasm Remains.

    ERIC Educational Resources Information Center

    Hill, Paul T.; Guin, Kacey; Celio, Mary Beth

    2003-01-01

    Argues that "A Nation at Risk" failed to address adequately problems of urban education, and thus the achievement gap between minority and white students still exists. Describes several problems that still plague low-performing urban schools, such as bureaucratic aversion to change, high levels of poverty, and low teacher quality and…

  18. 78 FR 76984 - Airworthiness Directives; Eurocopter France Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ... inspecting each jettisonable emergency exit window panel (window) for sealant, and removing any sealant that exists in the window's extruded sections. This AD was prompted by jettison tests during routine maintenance inspections that showed the windows failed to jettison. The actions of this AD are intended to...

  19. 78 FR 37156 - Airworthiness Directives; Eurocopter France Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-20

    ... inspecting each jettisonable emergency exit window panel (window) for sealant, and removing any sealant that exists in the window's extruded sections. This proposed AD is prompted by jettison tests during routine maintenance inspections that showed the windows failed to jettison. The proposed actions are intended to...

  20. Global Sales Training's Balancing Act

    ERIC Educational Resources Information Center

    Boehle, Sarah

    2010-01-01

    A one-size-fits-all global sales strategy that fails to take into account the cultural, regulatory, geographic, and economic differences that exist across borders is a blueprint for failure. For training organizations tasked with educating globally dispersed sales forces, the challenge is adapting to these differences while simultaneously…

  1. 22 CFR 34.18 - Waivers of indebtedness.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... known through the exercise of due diligence that an error existed but failed to take corrective action... elapsed between the erroneous payment and discovery of the error and notification of the employee; (D... to duty because of disability (supported by an acceptable medical certificate); and (D) Whether...

  2. UHF Television: Breaking the Monolith

    ERIC Educational Resources Information Center

    Oppenheim, Jerrold

    1975-01-01

    Advocates that the Federal Communications Council should remove unnecessary UHF restrictions to dramatically increase the number of UHF stations, put all existing stations on the UHF band, and license new low-power stations on the UHF channels, arguing that television fails to serve a sizable number of viewers. (Author/JM)

  3. The origin of neap-spring tidal cycles

    USGS Publications Warehouse

    Kvale, E.P.

    2006-01-01

    The origin of oceanic tides is a basic concept taught in most introductory college-level sedimentology/geology, oceanography, and astronomy courses. Tides are typically explained in the context of the equilibrium tidal theory model. Yet this model does not take into account real tides in many parts of the world. Not only does the equilibrium tidal model fail to explicate amphidromic circulation, it also does not explain diurnal tides in low latitude positions. It likewise fails to explain the existence of tide-dominated areas where neap-spring cycles are synchronized with the 27.32-day orbital cycle of the Moon (tropical month), rather than with the more familiar 29.52-day cycle of lunar phases (synodic month). Both types of neap-spring cycles can be recognized in the rock record. A complete explanation of the origin of tides should include a discussion of dynamic tidal theory. In the dynamic tidal model, tides resulting from the motions of the Moon in its orbit around the Earth and the Earth in its orbit around the Sun are modeled as products of the combined effects of a series of phantom satellites. The movement of each of these satellites, relative to the Earth's equator, creates its own tidal wave that moves around an amphidromic point. Each of these waves is referred to as a tidal constituent. The geometries of the ocean basins determine which of these constituents are amplified. Thus, the tide-raising potential for any locality on Earth can be conceptualized as the result of a series of tidal constituents specific to that region. A better understanding of tidal cycles opens up remarkable opportunities for research on tidal deposits with implications for, among other things, a more complete understanding of the tidal dynamics responsible for sediment transport and deposition, changes in Earth-Moon distance through time, and the possible influences tidal cycles may exert on organisms. ?? 2006 Elsevier B.V. All rights reserved.

  4. Integrated modelling of H-mode pedestal and confinement in JET-ILW

    NASA Astrophysics Data System (ADS)

    Saarelma, S.; Challis, C. D.; Garzotti, L.; Frassinetti, L.; Maggi, C. F.; Romanelli, M.; Stokes, C.; Contributors, JET

    2018-01-01

    A pedestal prediction model Europed is built on the existing EPED1 model by coupling it with core transport simulation using a Bohm-gyroBohm transport model to self-consistently predict JET-ILW power scan for hybrid plasmas that display weaker power degradation than the IPB98(y, 2) scaling of the energy confinement time. The weak power degradation is reproduced in the coupled core-pedestal simulation. The coupled core-pedestal model is further tested for a 3.0 MA plasma with the highest stored energy achieved in JET-ILW so far, giving a prediction of the stored plasma energy within the error margins of the measured experimental value. A pedestal density prediction model based on the neutral penetration is tested on a JET-ILW database giving a prediction with an average error of 17% from the experimental data when a parameter taking into account the fuelling rate is added into the model. However the model fails to reproduce the power dependence of the pedestal density implying missing transport physics in the model. The future JET-ILW deuterium campaign with increased heating power is predicted to reach plasma energy of 11 MJ, which would correspond to 11-13 MW of fusion power in equivalent deuterium-tritium plasma but with isotope effects on pedestal stability and core transport ignored.

  5. Nuclear matrix and structural and functional compartmentalization of the eucaryotic cell nucleus.

    PubMed

    Razin, S V; Borunova, V V; Iarovaia, O V; Vassetzky, Y S

    2014-07-01

    Becoming popular at the end of the 20th century, the concept of the nuclear matrix implies the existence of a nuclear skeleton that organizes functional elements in the cell nucleus. This review presents a critical analysis of the results obtained in the study of nuclear matrix in the light of current views on the organization of the cell nucleus. Numerous studies of nuclear matrix have failed to provide evidence of the existence of such a structure. Moreover, the existence of a filamentous structure that supports the nuclear compartmentalization appears to be unnecessary, since this function is performed by the folded genome itself.

  6. Decarbonation in an intracratonic setting: Insight from petrological-thermomechanical modeling

    NASA Astrophysics Data System (ADS)

    Gonzalez, Christopher M.; Gorczyk, Weronika

    2017-08-01

    Cratons form the stable core roots of the continental crust. Despite long-term stability, cratons have failed in the past. Cratonic destruction (e.g., North Atlantic Craton) due to chemical rejuvenation at the base of the lithosphere remains poorly constrained numerically. We use 2-D petrological-thermomechanical models to assess cratonic rifting characteristics and mantle CO2 degassing in the presence of a carbonated subcontinental lithospheric mantle (SCLM). We test two tectonothermal SCLM compositions: Archon (depleted) and Tecton (fertilized) using 2 CO2 wt % in the bulk composition to represent a metasomatized SCLM. We parameterize cratonic breakup via extensional duration (7-12 Ma; full breakup), tectonothermal age, TMoho (300-600°C), and crustal rheology. The two compositions with metasomatized SCLMs share similar rifting features and decarbonation trends during initial extension. However, we show long-term (>67 Ma) stability differences due to lithospheric density contrasts between SCLM compositions. The Tecton model shows convective removal and thinning of the metasomatized SCLM during failed rifting. The Archon composition remained stable, highlighting the primary role for SCLM density even when metasomatized at its base. In the short-term, three failed rifting characteristics emerge: failed rifting without decarbonation, failed rifting with decarbonation, and semifailed rifting with dry asthenospheric melting and decarbonation. Decarbonation trends were greatest in the failed rifts, reaching peak fluxes of 94 × 104 kg m-3. Increased TMoho did not alter the effects of rifting or decarbonation. Lastly, we show mantle regions where decarbonation, mantle melting in the presence of carbonate, and preservation of carbonated mantle occur during rifting.

  7. Imbalanced multi-modal multi-label learning for subcellular localization prediction of human proteins with both single and multiple sites.

    PubMed

    He, Jianjun; Gu, Hong; Liu, Wenqi

    2012-01-01

    It is well known that an important step toward understanding the functions of a protein is to determine its subcellular location. Although numerous prediction algorithms have been developed, most of them typically focused on the proteins with only one location. In recent years, researchers have begun to pay attention to the subcellular localization prediction of the proteins with multiple sites. However, almost all the existing approaches have failed to take into account the correlations among the locations caused by the proteins with multiple sites, which may be the important information for improving the prediction accuracy of the proteins with multiple sites. In this paper, a new algorithm which can effectively exploit the correlations among the locations is proposed by using gaussian process model. Besides, the algorithm also can realize optimal linear combination of various feature extraction technologies and could be robust to the imbalanced data set. Experimental results on a human protein data set show that the proposed algorithm is valid and can achieve better performance than the existing approaches.

  8. Underdamped scaled Brownian motion: (non-)existence of the overdamped limit in anomalous diffusion

    PubMed Central

    Bodrova, Anna S.; Chechkin, Aleksei V.; Cherstvy, Andrey G.; Safdari, Hadiseh; Sokolov, Igor M.; Metzler, Ralf

    2016-01-01

    It is quite generally assumed that the overdamped Langevin equation provides a quantitative description of the dynamics of a classical Brownian particle in the long time limit. We establish and investigate a paradigm anomalous diffusion process governed by an underdamped Langevin equation with an explicit time dependence of the system temperature and thus the diffusion and damping coefficients. We show that for this underdamped scaled Brownian motion (UDSBM) the overdamped limit fails to describe the long time behaviour of the system and may practically even not exist at all for a certain range of the parameter values. Thus persistent inertial effects play a non-negligible role even at significantly long times. From this study a general questions on the applicability of the overdamped limit to describe the long time motion of an anomalously diffusing particle arises, with profound consequences for the relevance of overdamped anomalous diffusion models. We elucidate our results in view of analytical and simulations results for the anomalous diffusion of particles in free cooling granular gases. PMID:27462008

  9. The New Politics of US Health Care Prices: Institutional Reconfiguration and the Emergence of All-Payer Claims Databases.

    PubMed

    Rocco, Philip; Kelly, Andrew S; Béland, Daniel; Kinane, Michael

    2017-02-01

    Prices are a significant driver of health care cost in the United States. Existing research on the politics of health system reform has emphasized the limited nature of policy entrepreneurs' efforts at solving the problem of rising prices through direct regulation at the state level. Yet this literature fails to account for how change agents in the states gradually reconfigured the politics of prices, forging new, transparency-based policy instruments called all-payer claims databases (APCDs), which are designed to empower consumers, purchasers, and states to make informed market and policy choices. Drawing on pragmatist institutional theory, this article shows how APCDs emerged as the dominant model for reforming health care prices. While APCD advocates faced significant institutional barriers to policy change, we show how they reconfigured existing ideas, tactical repertoires, and legal-technical infrastructures to develop a politically and technologically robust reform. Our analysis has important implications for theories of how change agents overcome structural barriers to health reform. Copyright © 2017 by Duke University Press.

  10. Texturing by cooling a metallic melt in a magnetic field.

    PubMed

    Tournier, Robert F; Beaugnon, Eric

    2009-02-01

    Processing in a magnetic field leads to the texturing of materials along an easy-magnetization axis when a minimum anisotropy energy exists at the processing temperature; the magnetic field can be applied to a particle assembly embedded into a liquid, or to a solid at a high diffusion temperature close to the melting temperature or between the liquidus and the solidus temperatures in a region of partial melting. It has been shown in many experiments that texturing is easy to achieve in congruent and noncongruent compounds by applying the field above the melting temperature T m or above the liquidus temperature of alloys. Texturing from a melt is successful when the overheating temperature is just a few degrees above T m and fails when the processing time above T m is too long or when the overheating temperature is too high; these observations indicate the presence of unmelted crystals above T m with a size depending on these two variables that act as growth nuclei. A recent model that predicts the existence of unmelted crystals above the melting temperature is used to calculate their radius in a bismuth melt.

  11. Policy design and performance of emissions trading markets: an adaptive agent-based analysis.

    PubMed

    Bing, Zhang; Qinqin, Yu; Jun, Bi

    2010-08-01

    Emissions trading is considered to be a cost-effective environmental economic instrument for pollution control. However, the pilot emissions trading programs in China have failed to bring remarkable success in the campaign for pollution control. The policy design of an emissions trading program is found to have a decisive impact on its performance. In this study, an artificial market for sulfur dioxide (SO2) emissions trading applying the agent-based model was constructed. The performance of the Jiangsu SO2 emissions trading market under different policy design scenario was also examined. Results show that the market efficiency of emissions trading is significantly affected by policy design and existing policies. China's coal-electricity price system is the principal factor influencing the performance of the SO2 emissions trading market. Transaction costs would also reduce market efficiency. In addition, current-level emissions discharge fee/tax and banking mechanisms do not distinctly affect policy performance. Thus, applying emissions trading in emission control in China should consider policy design and interaction with other existing policies.

  12. Secondary School Experiences of Male Recovering Substance Abusers

    ERIC Educational Resources Information Center

    Maher, Rebecca C.

    2012-01-01

    Problem: Adolescents who begin abusing substances, including alcohol, prescription drugs, and illegal drugs often fail in school suffering life-altering consequences (Cox, Zhang, Johnson, & Bender, 2007). While plentiful research exists on substance abuse, there is a dearth of research on the school experiences of recovering substance abusers.…

  13. An Examination of the Determinants of Top Management Support of Information Technology Projects

    ERIC Educational Resources Information Center

    Mahoney, Michael L.

    2011-01-01

    Despite compelling evidence that top management support promotes information technology project success, existing research fails to offer insight into the antecedents of top management support of such projects. This gap in the literature is significant since the exploitation of information technology offers organizations unique opportunities for…

  14. Online Schooling: A Cautionary Tale

    ERIC Educational Resources Information Center

    Saultz, Andrew; Fusarelli, Lance D.

    2017-01-01

    In this controversy piece, we portray online learning as growing too fast for existing regulatory structures to oversee and generally as having failed to live up to its potential. Operators, particularly for-profit operators, have generally not produced successful schools. We urge reforms of cyber schooling funding mechanisms, data systems, and…

  15. Jackie Cannon Learns the Importance of a Written Contract.

    ERIC Educational Resources Information Center

    Flygare, Thomas J.

    1983-01-01

    The Fifth Circuit Court of Appeals found that a Texas school superintendent, having failed to submit a written contract to the school board for execution, had no basis for holding that a property interest in employment existed. Certainty about binding obligations requires written agreements signed by both parties. (PB)

  16. Achieving and Maintaining Existing Building Sustainability Certification at Georgetown University

    ERIC Educational Resources Information Center

    Payant, Richard P.

    2013-01-01

    Sustainability is the promotion of high performance, healthful, energy-efficient, and environmentally stable buildings. Buildings intended for sustainable certification must meet guidelines developed by the Leadership in Energy and Environmental Design (LEED) of the U.S. Green Building Council. The problem is that LEED certification often fails to…

  17. Good Faith Efforts? Part II.

    ERIC Educational Resources Information Center

    Zirkel, Perry A.

    2000-01-01

    Regarding Catholic parents' suit against a suburban New York district for promoting occult activities, a federal court ruled in May 1999 that parents had failed to prove existence of the so- called Bedford program. This Solomon-like ruling also rejected First Amendment religious claims and 14th Amendment privacy claims. (MLH)

  18. An Exploration of Employer Perceptions of Graduate Student Employability

    ERIC Educational Resources Information Center

    Chhinzer, Nita; Russo, Anna Maria

    2018-01-01

    Purpose: The purpose of this paper is to explore employer perceptions of graduate student employability. This study is novel since existing research focused on employability is largely theoretic, remains focused on defining employability of undergraduates and largely fails to determine employer perceptions of factors that increase or decrease…

  19. An Empirical Comparison of Three Theories of Nonverbal Immediacy Exchange.

    ERIC Educational Resources Information Center

    Andersen, Peter A.; Guerrero, Laura K.; Jorgensen, Peter F.; Buller, David B.

    1998-01-01

    Provides a contrastive test of three immediacy-exchange theories: expectancy violations theory; discrepancy arousal theory; and cognitive valence theory. States findings from opposite-sex friend dyads (one of whom was an undergraduate student) failed to find unequivocal support for a single theory. Suggests existing immediacy-exchange theories…

  20. A Systemic Integration of Technology for New-Paradigm Education

    ERIC Educational Resources Information Center

    Watson, William R.; Watson, Sunnie Lee; Reigeluth, Charles M.

    2012-01-01

    Educational reform efforts have failed to create widespread improvement. The authors argue that rather than trying to improve the existing system of education, a new learner-centered paradigm is needed that supports individualized learning. Such a significantly different system of education will require the systemic application of technology to…

  1. Lessons Learned from Citizen Science in the Classroom

    ERIC Educational Resources Information Center

    Gray, Steven A.; Nicosia, Kristina; Jordan, Rebecca C.

    2012-01-01

    Mueller, Tippins, and Bryan's contrast of the current limitations of science education with the potential virtues of citizen science provides an important theoretical perspective about the future of democratized science and K-12 education. However, the authors fail to adequately address the existing barriers and constraints to moving…

  2. 15 CFR 8a.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 8a.115... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 8a.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  3. 49 CFR 25.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Transportation Office of the Secretary of Transportation NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION... fails to commit itself to take whatever remedial action is necessary in accordance with § 25.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  4. 10 CFR 1042.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... DEPARTMENT OF ENERGY (GENERAL PROVISIONS) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR... fails to commit itself to take whatever remedial action is necessary in accordance with § 1042.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  5. 38 CFR 23.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 23.110(a) to eliminate existing discrimination on the basis of sex or to...

  6. 41 CFR 101-4.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... System FEDERAL PROPERTY MANAGEMENT REGULATIONS GENERAL 4-NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 101-4.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  7. 10 CFR 1042.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... DEPARTMENT OF ENERGY (GENERAL PROVISIONS) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR... fails to commit itself to take whatever remedial action is necessary in accordance with § 1042.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  8. 43 CFR 41.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Public Lands: Interior Office of the Secretary of the Interior NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 41.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  9. 13 CFR 113.115 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Nondiscrimination on the Basis of Sex in Education Programs or Activities Receiving Federal Financial Assistance... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 113.110(a) to eliminate existing discrimination on the basis of sex or to...

  10. 41 CFR 101-4.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS GENERAL 4-NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 101-4.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  11. 49 CFR 25.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Transportation Office of the Secretary of Transportation NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION... fails to commit itself to take whatever remedial action is necessary in accordance with § 25.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  12. 38 CFR 23.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 23.110(a) to eliminate existing discrimination on the basis of sex or to...

  13. 41 CFR 101-4.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... System FEDERAL PROPERTY MANAGEMENT REGULATIONS GENERAL 4-NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 101-4.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  14. 18 CFR 1317.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 1317.110(a) to eliminate existing discrimination on the basis of sex or to...

  15. 24 CFR 3.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 3.110(a) to eliminate existing discrimination on the basis of sex or to...

  16. 13 CFR 113.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Nondiscrimination on the Basis of Sex in Education Programs or Activities Receiving Federal Financial Assistance... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 113.110(a) to eliminate existing discrimination on the basis of sex or to...

  17. 49 CFR 25.115 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Transportation Office of the Secretary of Transportation NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION... fails to commit itself to take whatever remedial action is necessary in accordance with § 25.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  18. 15 CFR 8a.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 8a.115... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 8a.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  19. 38 CFR 23.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 23.110(a) to eliminate existing discrimination on the basis of sex or to...

  20. 38 CFR 23.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 23.110(a) to eliminate existing discrimination on the basis of sex or to...

  1. 13 CFR 113.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Nondiscrimination on the Basis of Sex in Education Programs or Activities Receiving Federal Financial Assistance... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 113.110(a) to eliminate existing discrimination on the basis of sex or to...

  2. 43 CFR 41.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Public Lands: Interior Office of the Secretary of the Interior NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 41.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  3. 43 CFR 41.115 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Public Lands: Interior Office of the Secretary of the Interior NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 41.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  4. 15 CFR 8a.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 8a.115... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 8a.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  5. 18 CFR 1317.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 1317.110(a) to eliminate existing discrimination on the basis of sex or to...

  6. 38 CFR 23.115 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 23.110(a) to eliminate existing discrimination on the basis of sex or to...

  7. 49 CFR 25.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Transportation Office of the Secretary of Transportation NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION... fails to commit itself to take whatever remedial action is necessary in accordance with § 25.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  8. 18 CFR 1317.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 1317.110(a) to eliminate existing discrimination on the basis of sex or to...

  9. 22 CFR 146.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Foreign Relations DEPARTMENT OF STATE CIVIL RIGHTS NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION... fails to commit itself to take whatever remedial action is necessary in accordance with § 146.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  10. 15 CFR 8a.115 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 8a.115... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 8a.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  11. 41 CFR 101-4.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... System FEDERAL PROPERTY MANAGEMENT REGULATIONS GENERAL 4-NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 101-4.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  12. 10 CFR 1042.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... DEPARTMENT OF ENERGY (GENERAL PROVISIONS) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR... fails to commit itself to take whatever remedial action is necessary in accordance with § 1042.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  13. 13 CFR 113.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Nondiscrimination on the Basis of Sex in Education Programs or Activities Receiving Federal Financial Assistance... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 113.110(a) to eliminate existing discrimination on the basis of sex or to...

  14. 10 CFR 1042.115 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... DEPARTMENT OF ENERGY (GENERAL PROVISIONS) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR... fails to commit itself to take whatever remedial action is necessary in accordance with § 1042.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  15. 22 CFR 146.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Foreign Relations DEPARTMENT OF STATE CIVIL RIGHTS NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION... fails to commit itself to take whatever remedial action is necessary in accordance with § 146.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  16. 22 CFR 146.115 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Foreign Relations DEPARTMENT OF STATE CIVIL RIGHTS NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION... fails to commit itself to take whatever remedial action is necessary in accordance with § 146.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  17. 10 CFR 1042.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... DEPARTMENT OF ENERGY (GENERAL PROVISIONS) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR... fails to commit itself to take whatever remedial action is necessary in accordance with § 1042.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  18. 49 CFR 25.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Transportation Office of the Secretary of Transportation NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION... fails to commit itself to take whatever remedial action is necessary in accordance with § 25.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  19. 22 CFR 146.115 - Assurance required.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Foreign Relations DEPARTMENT OF STATE CIVIL RIGHTS NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION... fails to commit itself to take whatever remedial action is necessary in accordance with § 146.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  20. 24 CFR 3.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 3.110(a) to eliminate existing discrimination on the basis of sex or to...

  1. 43 CFR 41.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Public Lands: Interior Office of the Secretary of the Interior NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 41.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  2. 13 CFR 113.115 - Assurance required.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Nondiscrimination on the Basis of Sex in Education Programs or Activities Receiving Federal Financial Assistance... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 113.110(a) to eliminate existing discrimination on the basis of sex or to...

  3. 24 CFR 3.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 3.110(a) to eliminate existing discrimination on the basis of sex or to...

  4. 43 CFR 41.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Public Lands: Interior Office of the Secretary of the Interior NONDISCRIMINATION ON THE BASIS OF SEX IN... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 41.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  5. 15 CFR 8a.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 8a.115... assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 8a.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of...

  6. 24 CFR 3.115 - Assurance required.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 3.110(a) to eliminate existing discrimination on the basis of sex or to...

  7. 18 CFR 1317.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 1317.110(a) to eliminate existing discrimination on the basis of sex or to...

  8. 18 CFR 1317.115 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 1317.110(a) to eliminate existing discrimination on the basis of sex or to...

  9. 22 CFR 146.115 - Assurance required.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Foreign Relations DEPARTMENT OF STATE CIVIL RIGHTS NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION... fails to commit itself to take whatever remedial action is necessary in accordance with § 146.110(a) to eliminate existing discrimination on the basis of sex or to eliminate the effects of past discrimination...

  10. 24 CFR 3.115 - Assurance required.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... recipient to whom such assurance applies fails to commit itself to take whatever remedial action is necessary in accordance with § 3.110(a) to eliminate existing discrimination on the basis of sex or to...

  11. The Human Side of Quality: Employee Care and Empowerment.

    ERIC Educational Resources Information Center

    Thor, Linda M.

    Frequently, educational institutions seeking to implement Total Quality Management (TQM) as a means to improve institutional effectiveness, overemphasize training in the application of TQM tools and fail to fully address human needs and concerns, such as the critical issue of employee empowerment. Four principal barriers exist to adequately…

  12. Teaching About Women to Male-Identified Students.

    ERIC Educational Resources Information Center

    Turkel, Kathleen Doherty

    1986-01-01

    The female students taking women's studies courses today are different from those in the early 1970s. Many are unconsciously male-identified--fully buying into predominant male viewpoints--and thus fail to recognize the connections which exist between the general conditions restricting the opportunities and welfare of women and their own…

  13. Wellness: A Review of Theory and Measurement for Counselors

    ERIC Educational Resources Information Center

    Roscoe, Lauren J.

    2009-01-01

    Wellness is considered the paradigm of counseling and development (J. E. Myers, 1991, 1992). However, researchers have failed to agree on a definition or on the dimensional structure of wellness. Furthermore, existing quantitative wellness instruments are inadequate for capturing the complexity of wellness. The author reviews wellness theory and…

  14. Collaborative Learning from Personal Cases in a Principal Preparation Programme

    ERIC Educational Resources Information Center

    Shaked, Haim; Schechter, Chen; Michalsky, Tova

    2018-01-01

    Existing preparation programmes for school principals have been widely criticized for failing to prepare their students adequately for their future roles. This study investigated a workshop at a principal preparation programme which focused on collaborative learning from personal real-life cases, exploring its potential contribution to the…

  15. 30 CFR 285.913 - What happens if I fail to comply with my approved decommissioning application?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... approved decommissioning application? 285.913 Section 285.913 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE RENEWABLE ENERGY ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF Decommissioning Compliance with An Approved Decommissioning Application § 285.913 What...

  16. Our Last Best Shot: Guiding Our Children through Early Adolescence.

    ERIC Educational Resources Information Center

    Stepp, Laura Sessions

    Noting that amid the enormous change inherent in early adolescence, many parents fail to distinguish between behaviors signaling healthy growth and those indicating troubled development, this book uses the stories of 12 representative adolescents from various locations in the United States and existing research literature to provide guidance on…

  17. The Search for the Pentaquark

    NASA Astrophysics Data System (ADS)

    Eyrich, Wolfgang

    2007-01-01

    In the last two years, starting with the LEPS collaboration1 several experiments reported evidence for a manifestly exotic narrow state with a mass of about 1530 MeV/c2. The state was found to decay into K0p and K+n. This object with strangeness S = +1 was named Θ+ and identified with the lightest exotic antidecuplet baryon predicted in the soliton model2. Many experiments have scanned their data for a pentaquark signal with varying results. Some searches resulted in evidence for the Θ+ while others fail to produce any narrow structure in the region of interest. Currently, a number of high statistics experiments are being evaluated with the goal to confirm or refute the existence of the Θ+. In this contribution the experimental status and further prospects will be discussed.

  18. Phonon Mechanisms for Excess Heat Capacity in Membrane Isolated Superconducting Transition Edge Sensors

    NASA Technical Reports Server (NTRS)

    Chervenak, James A.

    2012-01-01

    The mechanics of phonon transport in membrane-isolated superconducting transition edge sensors is discussed. Surveys of the literature on this type of sensor reveal a number of designs with excess heat capacity and a smaller subset that exhibit decoupling of the superconducting film from the underlying dielectric. A simple model is addressed in which the membrane, despite its thermal isolation, fails to fully thermalize to the temperature of the metal film heating it. A population of phonons exists which is emitted by the metal film, partially thermalizes the dielectric and is then reabsorbed in the metal film without escaping from the device structure to the thermal bath. The size of this population and its contribution to the heat capacity are estimated for several device scenarios.

  19. Testing for significance of phase synchronisation dynamics in the EEG.

    PubMed

    Daly, Ian; Sweeney-Reed, Catherine M; Nasuto, Slawomir J

    2013-06-01

    A number of tests exist to check for statistical significance of phase synchronisation within the Electroencephalogram (EEG); however, the majority suffer from a lack of generality and applicability. They may also fail to account for temporal dynamics in the phase synchronisation, regarding synchronisation as a constant state instead of a dynamical process. Therefore, a novel test is developed for identifying the statistical significance of phase synchronisation based upon a combination of work characterising temporal dynamics of multivariate time-series and Markov modelling. We show how this method is better able to assess the significance of phase synchronisation than a range of commonly used significance tests. We also show how the method may be applied to identify and classify significantly different phase synchronisation dynamics in both univariate and multivariate datasets.

  20. Estimating Mixture of Gaussian Processes by Kernel Smoothing

    PubMed Central

    Huang, Mian; Li, Runze; Wang, Hansheng; Yao, Weixin

    2014-01-01

    When the functional data are not homogeneous, e.g., there exist multiple classes of functional curves in the dataset, traditional estimation methods may fail. In this paper, we propose a new estimation procedure for the Mixture of Gaussian Processes, to incorporate both functional and inhomogeneous properties of the data. Our method can be viewed as a natural extension of high-dimensional normal mixtures. However, the key difference is that smoothed structures are imposed for both the mean and covariance functions. The model is shown to be identifiable, and can be estimated efficiently by a combination of the ideas from EM algorithm, kernel regression, and functional principal component analysis. Our methodology is empirically justified by Monte Carlo simulations and illustrated by an analysis of a supermarket dataset. PMID:24976675

  1. Nonlinear BCJR equalizer for suppression of intrachannel nonlinearities in 40 Gb/s optical communications systems.

    PubMed

    Djordjevic, Ivan B; Vasic, Bane

    2006-05-29

    A maximum a posteriori probability (MAP) symbol decoding supplemented with iterative decoding is proposed as an effective mean for suppression of intrachannel nonlinearities. The MAP detector, based on Bahl-Cocke-Jelinek-Raviv algorithm, operates on the channel trellis, a dynamical model of intersymbol interference, and provides soft-decision outputs processed further in an iterative decoder. A dramatic performance improvement is demonstrated. The main reason is that the conventional maximum-likelihood sequence detector based on Viterbi algorithm provides hard-decision outputs only, hence preventing the soft iterative decoding. The proposed scheme operates very well in the presence of strong intrachannel intersymbol interference, when other advanced forward error correction schemes fail, and it is also suitable for 40 Gb/s upgrade over existing 10 Gb/s infrastructure.

  2. Exploring the sequential lineup advantage using WITNESS.

    PubMed

    Goodsell, Charles A; Gronlund, Scott D; Carlson, Curt A

    2010-12-01

    Advocates claim that the sequential lineup is an improvement over simultaneous lineup procedures, but no formal (quantitatively specified) explanation exists for why it is better. The computational model WITNESS (Clark, Appl Cogn Psychol 17:629-654, 2003) was used to develop theoretical explanations for the sequential lineup advantage. In its current form, WITNESS produced a sequential advantage only by pairing conservative sequential choosing with liberal simultaneous choosing. However, this combination failed to approximate four extant experiments that exhibited large sequential advantages. Two of these experiments became the focus of our efforts because the data were uncontaminated by likely suspect position effects. Decision-based and memory-based modifications to WITNESS approximated the data and produced a sequential advantage. The next step is to evaluate the proposed explanations and modify public policy recommendations accordingly.

  3. Evaluating the Evidence for the General Factor of Personality across Multiple Inventories

    PubMed Central

    Hopwood, Christopher J.; Wright, Aidan G.C.; Donnellan, M. Brent

    2012-01-01

    A general factor of personality (GFP) has been proposed as the apex of a personality trait hierarchy that explains covariance among the lower-order factors measured by various personality inventories. In this study we evaluated the GFP hypothesis across several personality inventories, unlike most previous research in which the GFP has been derived from individual instruments in isolation. Exploratory analyses did not produce substantial evidence for the existence of a single cross-instrument higher-order factor of factors and efforts to specify a range of GFP-inspired models in a confirmatory framework led to significant estimation difficulties and poor fit to the data. Overall these results fail to support a common GFP that is positioned at the top of a personality trait hierarchy. PMID:22879686

  4. Why one-size-fits-all vaso-modulatory interventions fail to control glioma invasion: in silico insights.

    PubMed

    Alfonso, J C L; Köhn-Luque, A; Stylianopoulos, T; Feuerhake, F; Deutsch, A; Hatzikirou, H

    2016-11-23

    Gliomas are highly invasive brain tumours characterised by poor prognosis and limited response to therapy. There is an ongoing debate on the therapeutic potential of vaso-modulatory interventions against glioma invasion. Prominent vasculature-targeting therapies involve tumour blood vessel deterioration and normalisation. The former aims at tumour infarction and nutrient deprivation induced by blood vessel occlusion/collapse. In contrast, the therapeutic intention of normalising the abnormal tumour vasculature is to improve the efficacy of conventional treatment modalities. Although these strategies have shown therapeutic potential, it remains unclear why they both often fail to control glioma growth. To shed some light on this issue, we propose a mathematical model based on the migration/proliferation dichotomy of glioma cells in order to investigate why vaso-modulatory interventions have shown limited success in terms of tumour clearance. We found the existence of a critical cell proliferation/diffusion ratio that separates glioma responses to vaso-modulatory interventions into two distinct regimes. While for tumours, belonging to one regime, vascular modulations reduce the front speed and increase the infiltration width, for those in the other regime, the invasion speed increases and infiltration width decreases. We discuss how these in silico findings can be used to guide individualised vaso-modulatory approaches to improve treatment success rates.

  5. The integrity of welded interfaces in ultra-high molecular weight polyethylene: Part 2--interface toughness.

    PubMed

    Haughie, David W; Buckley, C Paul; Wu, Junjie

    2006-07-01

    In Part 2 of a study of welding of ultra-high molecular weight polyethylene (UHMWPE), experiments were conducted to measure the interfacial fracture energy of butt welds, for various welding times and temperatures above the melting point. Their toughness was investigated at 37 degrees C in terms of their fracture energy, obtained by adapting the essential work of fracture (EWF) method. However, a proportion of the welded samples (generally decreasing with increasing welding time or temperature) failed in dual ductile/brittle mode, hence invalidating the EWF test. Even those failing in purely ductile mode showed a measurable interface work of fracture only for the highest weld temperature and time: 188 degrees C and 90 min. Results from the model presented in Part 1 show that this corresponds to the maximum reptated molecular weight reaching close to the peak in the molar mass distribution. Hence this work provides the first experimental evidence that the slow rate of self-diffusion in UHMWPE leads to welded interfaces acting as low-toughness crack paths. Since such interfaces exist around every powder particle in processed UHMWPE this problem cannot be avoided, and it must be accommodated in design of hip and knee bearing surfaces made from this polymer.

  6. Why one-size-fits-all vaso-modulatory interventions fail to control glioma invasion: in silico insights

    NASA Astrophysics Data System (ADS)

    Alfonso, J. C. L.; Köhn-Luque, A.; Stylianopoulos, T.; Feuerhake, F.; Deutsch, A.; Hatzikirou, H.

    2016-11-01

    Gliomas are highly invasive brain tumours characterised by poor prognosis and limited response to therapy. There is an ongoing debate on the therapeutic potential of vaso-modulatory interventions against glioma invasion. Prominent vasculature-targeting therapies involve tumour blood vessel deterioration and normalisation. The former aims at tumour infarction and nutrient deprivation induced by blood vessel occlusion/collapse. In contrast, the therapeutic intention of normalising the abnormal tumour vasculature is to improve the efficacy of conventional treatment modalities. Although these strategies have shown therapeutic potential, it remains unclear why they both often fail to control glioma growth. To shed some light on this issue, we propose a mathematical model based on the migration/proliferation dichotomy of glioma cells in order to investigate why vaso-modulatory interventions have shown limited success in terms of tumour clearance. We found the existence of a critical cell proliferation/diffusion ratio that separates glioma responses to vaso-modulatory interventions into two distinct regimes. While for tumours, belonging to one regime, vascular modulations reduce the front speed and increase the infiltration width, for those in the other regime, the invasion speed increases and infiltration width decreases. We discuss how these in silico findings can be used to guide individualised vaso-modulatory approaches to improve treatment success rates.

  7. A Passive System Reliability Analysis for a Station Blackout

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

    Brunett, Acacia; Bucknor, Matthew; Grabaskas, David

    2015-05-03

    The latest iterations of advanced reactor designs have included increased reliance on passive safety systems to maintain plant integrity during unplanned sequences. While these systems are advantageous in reducing the reliance on human intervention and availability of power, the phenomenological foundations on which these systems are built require a novel approach to a reliability assessment. Passive systems possess the unique ability to fail functionally without failing physically, a result of their explicit dependency on existing boundary conditions that drive their operating mode and capacity. Argonne National Laboratory is performing ongoing analyses that demonstrate various methodologies for the characterization of passivemore » system reliability within a probabilistic framework. Two reliability analysis techniques are utilized in this work. The first approach, the Reliability Method for Passive Systems, provides a mechanistic technique employing deterministic models and conventional static event trees. The second approach, a simulation-based technique, utilizes discrete dynamic event trees to treat time- dependent phenomena during scenario evolution. For this demonstration analysis, both reliability assessment techniques are used to analyze an extended station blackout in a pool-type sodium fast reactor (SFR) coupled with a reactor cavity cooling system (RCCS). This work demonstrates the entire process of a passive system reliability analysis, including identification of important parameters and failure metrics, treatment of uncertainties and analysis of results.« less

  8. Autonomous Component Health Management with Failed Component Detection, Identification, and Avoidance

    NASA Technical Reports Server (NTRS)

    Davis, Robert N.; Polites, Michael E.; Trevino, Luis C.

    2004-01-01

    This paper details a novel scheme for autonomous component health management (ACHM) with failed actuator detection and failed sensor detection, identification, and avoidance. This new scheme has features that far exceed the performance of systems with triple-redundant sensing and voting, yet requires fewer sensors and could be applied to any system with redundant sensing. Relevant background to the ACHM scheme is provided, and the simulation results for the application of that scheme to a single-axis spacecraft attitude control system with a 3rd order plant and dual-redundant measurement of system states are presented. ACHM fulfills key functions needed by an integrated vehicle health monitoring (IVHM) system. It is: autonomous; adaptive; works in realtime; provides optimal state estimation; identifies failed components; avoids failed components; reconfigures for multiple failures; reconfigures for intermittent failures; works for hard-over, soft, and zero-output failures; and works for both open- and closed-loop systems. The ACHM scheme combines a prefilter that generates preliminary state estimates, detects and identifies failed sensors and actuators, and avoids the use of failed sensors in state estimation with a fixed-gain Kalman filter that generates optimal state estimates and provides model-based state estimates that comprise an integral part of the failure detection logic. The results show that ACHM successfully isolates multiple persistent and intermittent hard-over, soft, and zero-output failures. It is now ready to be tested on a computer model of an actual system.

  9. Plasma Brightenings in a Failed Solar Filament Eruption

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

    Li, Y.; Ding, M. D., E-mail: yingli@nju.edu.cn

    Failed filament eruptions are solar eruptions that are not associated with coronal mass ejections. In a failed filament eruption, the filament materials usually show some ascending and falling motions as well as generating bright EUV emissions. Here we report a failed filament eruption (SOL2016-07-22) that occurred in a quiet-Sun region observed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory . In this event, the filament spreads out but gets confined by the surrounding magnetic field. When interacting with the ambient magnetic field, the filament material brightens up and flows along the magnetic field lines through the coronamore » to the chromosphere. We find that some materials slide down along the lifting magnetic structure containing the filament and impact the chromosphere, and through kinetic energy dissipation, cause two ribbon-like brightenings in a wide temperature range. There is evidence suggesting that magnetic reconnection occurs between the filament magnetic structure and the surrounding magnetic fields where filament plasma is heated to coronal temperatures. In addition, thread-like brightenings show up on top of the erupting magnetic fields at low temperatures, which might be produced by an energy imbalance from a fast drop of radiative cooling due to plasma rarefaction. Thus, this single event of a failed filament eruption shows the existence of a variety of plasma brightenings that may be caused by completely different heating mechanisms.« less

  10. A cost minimisation and Bayesian inference model predicts startle reflex modulation across species.

    PubMed

    Bach, Dominik R

    2015-04-07

    In many species, rapid defensive reflexes are paramount to escaping acute danger. These reflexes are modulated by the state of the environment. This is exemplified in fear-potentiated startle, a more vigorous startle response during conditioned anticipation of an unrelated threatening event. Extant explanations of this phenomenon build on descriptive models of underlying psychological states, or neural processes. Yet, they fail to predict invigorated startle during reward anticipation and instructed attention, and do not explain why startle reflex modulation evolved. Here, we fill this lacuna by developing a normative cost minimisation model based on Bayesian optimality principles. This model predicts the observed pattern of startle modification by rewards, punishments, instructed attention, and several other states. Moreover, the mathematical formalism furnishes predictions that can be tested experimentally. Comparing the model with existing data suggests a specific neural implementation of the underlying computations which yields close approximations to the optimal solution under most circumstances. This analysis puts startle modification into the framework of Bayesian decision theory and predictive coding, and illustrates the importance of an adaptive perspective to interpret defensive behaviour across species. Copyright © 2015 The Author. Published by Elsevier Ltd.. All rights reserved.

  11. Northern Hemisphere Winter Climate Response to Greenhouse Gas, Ozone, Solar and Volcanic Forcing

    NASA Technical Reports Server (NTRS)

    Shindell, Drew T.; Schmidt, Gavin A.; Miller, Ron L.; Rind, David; Hansen, James E. (Technical Monitor)

    2001-01-01

    The Goddard Institute for Space Studies (GISS) climate/middle atmosphere model has been used to study the impacts of increasing greenhouse gases, polar ozone depletion, volcanic eruptions, and solar cycle variability. We focus on the projection of the induced responses onto Northern Hemisphere winter surface climate. Changes in the model's surface climate take place largely through enhancement of existing variability patterns, with greenhouse gases, polar ozone depletion and volcanic eruptions primarily affecting the Arctic Oscillation (AO) pattern. Perturbations descend from the stratosphere to the surface in the model by altering the propagation of planetary waves coming up from the surface, in accord with observational evidence. Models lacking realistic stratospheric dynamics fail to capture these wave flux changes. The results support the conclusion that the stratosphere plays a crucial role in recent AO trends. We show that in our climate model, while ozone depletion has a significant effect, greenhouse gas forcing is the only one capable of causing the large, sustained increase in the AO observed over recent decades. This suggests that the AO trend, and a concurrent strengthening of the stratospheric vortex over the Arctic, are very likely anthropogenic in origin.

  12. Electro-osmotic flow of a model electrolyte

    NASA Astrophysics Data System (ADS)

    Zhu, Wei; Singer, Sherwin J.; Zheng, Zhi; Conlisk, A. T.

    2005-04-01

    Electro-osmotic flow is studied by nonequilibrium molecular dynamics simulations in a model system chosen to elucidate various factors affecting the velocity profile and facilitate comparison with existing continuum theories. The model system consists of spherical ions and solvent, with stationary, uniformly charged walls that make a channel with a height of 20 particle diameters. We find that hydrodynamic theory adequately describes simple pressure-driven (Poiseuille) flow in this model. However, Poisson-Boltzmann theory fails to describe the ion distribution in important situations, and therefore continuum fluid dynamics based on the Poisson-Boltzmann ion distribution disagrees with simulation results in those situations. The failure of Poisson-Boltzmann theory is traced to the exclusion of ions near the channel walls resulting from reduced solvation of the ions in that region. When a corrected ion distribution is used as input for hydrodynamic theory, agreement with numerical simulations is restored. An analytic theory is presented that demonstrates that repulsion of the ions from the channel walls increases the flow rate, and attraction to the walls has the opposite effect. A recent numerical study of electro-osmotic flow is reanalyzed in the light of our findings, and the results conform well to our conclusions for the model system.

  13. Simultaneous Tensor Decomposition and Completion Using Factor Priors.

    PubMed

    Chen, Yi-Lei; Hsu, Chiou-Ting Candy; Liao, Hong-Yuan Mark

    2013-08-27

    Tensor completion, which is a high-order extension of matrix completion, has generated a great deal of research interest in recent years. Given a tensor with incomplete entries, existing methods use either factorization or completion schemes to recover the missing parts. However, as the number of missing entries increases, factorization schemes may overfit the model because of incorrectly predefined ranks, while completion schemes may fail to interpret the model factors. In this paper, we introduce a novel concept: complete the missing entries and simultaneously capture the underlying model structure. To this end, we propose a method called Simultaneous Tensor Decomposition and Completion (STDC) that combines a rank minimization technique with Tucker model decomposition. Moreover, as the model structure is implicitly included in the Tucker model, we use factor priors, which are usually known a priori in real-world tensor objects, to characterize the underlying joint-manifold drawn from the model factors. We conducted experiments to empirically verify the convergence of our algorithm on synthetic data, and evaluate its effectiveness on various kinds of real-world data. The results demonstrate the efficacy of the proposed method and its potential usage in tensor-based applications. It also outperforms state-of-the-art methods on multilinear model analysis and visual data completion tasks.

  14. Constraining 3-PG with a new δ13C submodel: a test using the δ13C of tree rings.

    PubMed

    Wei, Liang; Marshall, John D; Link, Timothy E; Kavanagh, Kathleen L; DU, Enhao; Pangle, Robert E; Gag, Peter J; Ubierna, Nerea

    2014-01-01

    A semi-mechanistic forest growth model, 3-PG (Physiological Principles Predicting Growth), was extended to calculate δ(13)C in tree rings. The δ(13)C estimates were based on the model's existing description of carbon assimilation and canopy conductance. The model was tested in two ~80-year-old natural stands of Abies grandis (grand fir) in northern Idaho. We used as many independent measurements as possible to parameterize the model. Measured parameters included quantum yield, specific leaf area, soil water content and litterfall rate. Predictions were compared with measurements of transpiration by sap flux, stem biomass, tree diameter growth, leaf area index and δ(13)C. Sensitivity analysis showed that the model's predictions of δ(13)C were sensitive to key parameters controlling carbon assimilation and canopy conductance, which would have allowed it to fail had the model been parameterized or programmed incorrectly. Instead, the simulated δ(13)C of tree rings was no different from measurements (P > 0.05). The δ(13)C submodel provides a convenient means of constraining parameter space and avoiding model artefacts. This δ(13)C test may be applied to any forest growth model that includes realistic simulations of carbon assimilation and transpiration. © 2013 John Wiley & Sons Ltd.

  15. Intra-articular laser treatment plus Platelet Rich Plasma (PRP) significantly reduces pain in many patients who had failed prior PRP treatment

    NASA Astrophysics Data System (ADS)

    Prodromos, Chadwick C.; Finkle, Susan; Dawes, Alexander; Dizon, Angelo

    2018-02-01

    INTRODUCTION: In our practice Platelet Rich Plasma (PRP) injections effectively reduce pain in most but not all arthritic patients. However, for patients who fail PRP treatment, no good alternative currently exists except total joint replacement surgery. Low level laser therapy (LLLT) on the surface of the skin has not been helpful for arthritis patients in our experience. However, we hypothesized that intra-articular laser treatment would be an effective augmentation to PRP injection and would increase its efficacy in patients who had failed prior PRP injection alone. METHODS: We offered Intra-articular Low Level Laser Therapy (IAL) treatment in conjunction with repeat PRP injection to patients who had received no benefit from PRP injection alone at our center. They were the treatment group. They were not charged for PRP or IAL. They also served as a historical control group since they had all had failed PRP treatment alone. 28 patients (30 joints) accepted treatment after informed consent. 22 knees, 4 hips, 2 shoulder glenohumeral joints and 1 first carpo-metacarpal (1st CMC) joint were treated RESULTS: All patients were followed up at 1 month and no adverse events were seen from the treatment. At 6 months post treatment 46% of patients had good outcomes, and at 1 year 17% still showed improvement after treatment. 11 patients failed treatment and went on to joint replacement. DISCUSSION: A single treatment of IAL with PRP salvaged 46% of patients who had failed PRP treatment alone, allowing avoidance of surgery and good pain control.

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

    DTIC Science & Technology

    2006-12-01

    Antecedents and Consequences of Failed Governance : the Enron Example. Corporate Governance , 5: 5. Garrett, G., & Rendon, R. 2005(a). Contract Management... government organization because NAVFAC faces competition analogous to the corporate world. If NAVFAC fails to provide adequate services, the ...applicable to NAVFAC even though NAVFAC is a government organization because NAVFAC faces competition analogous to the corporate world. If NAVFAC fails to

  17. 76 FR 19278 - Airworthiness Directives; The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-07

    ... are proposing this AD to detect and correct cracking in the fail-safe interlayer of certain No. 2 and... to detect and correct cracking in the fail-safe interlayer of certain No. 2 and No. 3 glass windows... cracking in the fail-safe interlayer of certain No. 2 and No. 3 glass windows, which could result in loss...

  18. The cost of quality: Implementing generalization and suppression for anonymizing biomedical data with minimal information loss.

    PubMed

    Kohlmayer, Florian; Prasser, Fabian; Kuhn, Klaus A

    2015-12-01

    With the ARX data anonymization tool structured biomedical data can be de-identified using syntactic privacy models, such as k-anonymity. Data is transformed with two methods: (a) generalization of attribute values, followed by (b) suppression of data records. The former method results in data that is well suited for analyses by epidemiologists, while the latter method significantly reduces loss of information. Our tool uses an optimal anonymization algorithm that maximizes output utility according to a given measure. To achieve scalability, existing optimal anonymization algorithms exclude parts of the search space by predicting the outcome of data transformations regarding privacy and utility without explicitly applying them to the input dataset. These optimizations cannot be used if data is transformed with generalization and suppression. As optimal data utility and scalability are important for anonymizing biomedical data, we had to develop a novel method. In this article, we first confirm experimentally that combining generalization with suppression significantly increases data utility. Next, we proof that, within this coding model, the outcome of data transformations regarding privacy and utility cannot be predicted. As a consequence, existing algorithms fail to deliver optimal data utility. We confirm this finding experimentally. The limitation of previous work can be overcome at the cost of increased computational complexity. However, scalability is important for anonymizing data with user feedback. Consequently, we identify properties of datasets that may be predicted in our context and propose a novel and efficient algorithm. Finally, we evaluate our solution with multiple datasets and privacy models. This work presents the first thorough investigation of which properties of datasets can be predicted when data is anonymized with generalization and suppression. Our novel approach adopts existing optimization strategies to our context and combines different search methods. The experiments show that our method is able to efficiently solve a broad spectrum of anonymization problems. Our work shows that implementing syntactic privacy models is challenging and that existing algorithms are not well suited for anonymizing data with transformation models which are more complex than generalization alone. As such models have been recommended for use in the biomedical domain, our results are of general relevance for de-identifying structured biomedical data. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Recognition during recall failure: Semantic feature matching as a mechanism for recognition of semantic cues when recall fails.

    PubMed

    Cleary, Anne M; Ryals, Anthony J; Wagner, Samantha R

    2016-01-01

    Research suggests that a feature-matching process underlies cue familiarity-detection when cued recall with graphemic cues fails. When a test cue (e.g., potchbork) overlaps in graphemic features with multiple unrecalled studied items (e.g., patchwork, pitchfork, pocketbook, pullcork), higher cue familiarity ratings are given during recall failure of all of the targets than when the cue overlaps in graphemic features with only one studied target and that target fails to be recalled (e.g., patchwork). The present study used semantic feature production norms (McRae et al., Behavior Research Methods, Instruments, & Computers, 37, 547-559, 2005) to examine whether the same holds true when the cues are semantic in nature (e.g., jaguar is used to cue cheetah). Indeed, test cues (e.g., cedar) that overlapped in semantic features (e.g., a_tree, has_bark, etc.) with four unretrieved studied items (e.g., birch, oak, pine, willow) received higher cue familiarity ratings during recall failure than test cues that overlapped in semantic features with only two (also unretrieved) studied items (e.g., birch, oak), which in turn received higher familiarity ratings during recall failure than cues that did not overlap in semantic features with any studied items. These findings suggest that the feature-matching theory of recognition during recall failure can accommodate recognition of semantic cues during recall failure, providing a potential mechanism for conceptually-based forms of cue recognition during target retrieval failure. They also provide converging evidence for the existence of the semantic features envisaged in feature-based models of semantic knowledge representation and for those more concretely specified by the production norms of McRae et al. (Behavior Research Methods, Instruments, & Computers, 37, 547-559, 2005).

  20. The graphics calculator in mathematics education: A critical review of recent research

    NASA Astrophysics Data System (ADS)

    Penglase, Marina; Arnold, Stephen

    1996-04-01

    The graphics calculator, sometimes referred to as the "super calculator," has sparked great interest among mathematics educators. Considered by many to be a tool which has the potential to revolutionise mathematics education, a significant amount of research has been conducted into its effectiveness as a tool for instruction and learning within precalculus and calculus courses, specifically in the study of functions, graphing and modelling. Some results suggest that these devices (a) can facilitate the learning of functions and graphing concepts and the development of spatial visualisation skills; (b) promote mathematical investigation and exploration; and (c) encourage a shift in emphasis from algebraic manipulation and proof to graphical investigation and examination of the relationship between graphical, algebraic and geometric representations. Other studies, however, indicate that there is still a need for manipulative techniques in the learning of function and graphing concepts, that the use of graphics calculators may not facilitate the learning of particular precalculus topics, and that some "de-skilling" may occur, especially among males. It is the contention of this paper, however, that much of the research in this new and important field fails to provide clear guidance or even to inform debate in adequate ways regarding the role of graphics calculators in mathematics teaching and learning. By failing to distinguish the role of the tool from that of the instructional process, many studies reviewed could be more appropriately classified as "program evaluations" rather than as research on the graphics calculator per se. Further, claims regarding the effectiveness of the graphics calculator as a tool for learning frequently fail to recognise that judgments of effectiveness result directly from existing assumptions regarding both assessment practice and student "achievement."

  1. Trust, but verify - Accuracy of clinical commercial radiation Treatment Planning Systems

    NASA Astrophysics Data System (ADS)

    Lehmann, J.; Kenny, J.; Lye, J.; Dunn, L.; Williams, I.

    2014-03-01

    Computer based Treatment Planning Systems (TPS) are used worldwide to design and calculate treatment plans for treating radiation therapy patients. TPS are generally well designed and thoroughly tested by their developers and local physicists prior to clinical use. However, the wide-reaching impact of their accuracy warrants ongoing vigilance. This work reviews the findings of the Australian national audit system and provides recommendations for checks of TPS. The Australian Clinical Dosimetry Service (ACDS) has designed and implemented a national system of audits, currently in a three year test phase. The Level III audits verify the accuracy of a beam model of a facility's TPS through a comparison of measurements with calculation at selected points in an anthropomorphic phantom. The plans are prescribed by the ACDS and all measurement equipment is brought in for independent onsite measurements. In this first version of audits, plans are comparatively simple, involving asymmetric fields, wedges and inhomogeneities. The ACDS has performed 14 Level III audits to-date. Six audits returned at least one measurement at Action Level, indicating that the measured dose differed more than 3.3% (but less than 5%) from the planned dose. Two audits failed (difference >5%). One fail was caused by a data transmission error coupled with quality assurance (QA) not being performed. The second fail was investigated and reduced to Action Level with the onsite audit team finding phantom setup at treatment a contributing factor. The Action Level results are attributed to small dose calculation deviations within the TPS, which are investigated and corrected by the facilities. Small deviations exist in clinical TPS which can add up and can combine with output variations to result in unacceptable variations. Ongoing checks and independent audits are recommended.

  2. Demonstration of Advanced EMI Models for Live-Site UXO Discrimination at Waikoloa, Hawaii

    DTIC Science & Technology

    2015-12-01

    magnetic source models PNN Probabilistic Neural Network SERDP Strategic Environmental Research and Development Program SLO San Luis Obispo...SNR Signal to noise ratio SVM Support vector machine TD Time Domain TEMTADS Time Domain Electromagnetic Towed Array Detection System TOI... intrusive procedure, which was used by Parsons at WMA, failed to document accurately all intrusive results, or failed to detect and clear all UXO like

  3. 75 FR 9809 - Airworthiness Directives; Airbus Model A330-243, -341, -342, and -343 Airplanes; and Model A340...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-04

    ..., as a consequence of the over-torque, fail and move away, it would lead to loss of the vertical load pins, which could result in loss of the primary and/or secondary load path of the forward and/or aft..., as a consequence of the over-torque, fail and move away, it would lead to loss of the vertical load...

  4. Lyapunov-Based Sensor Failure Detection And Recovery For The Reverse Water Gas Shift Process

    NASA Technical Reports Server (NTRS)

    Haralambous, Michael G.

    2001-01-01

    Livingstone, a model-based AI software system, is planned for use in the autonomous fault diagnosis, reconfiguration, and control of the oxygen-producing reverse water gas shift (RWGS) process test-bed located in the Applied Chemistry Laboratory at KSC. In this report the RWGS process is first briefly described and an overview of Livingstone is given. Next, a Lyapunov-based approach for detecting and recovering from sensor failures, differing significantly from that used by Livingstone, is presented. In this new method, models used are in terms of the defining differential equations of system components, thus differing from the qualitative, static models used by Livingstone. An easily computed scalar inequality constraint, expressed in terms of sensed system variables, is used to determine the existence of sensor failures. In the event of sensor failure, an observer/estimator is used for determining which sensors have failed. The theory underlying the new approach is developed. Finally, a recommendation is made to use the Lyapunov-based approach to complement the capability of Livingstone and to use this combination in the RWGS process.

  5. LYAPUNOV-Based Sensor Failure Detection and Recovery for the Reverse Water Gas Shift Process

    NASA Technical Reports Server (NTRS)

    Haralambous, Michael G.

    2002-01-01

    Livingstone, a model-based AI software system, is planned for use in the autonomous fault diagnosis, reconfiguration, and control of the oxygen-producing reverse water gas shift (RWGS) process test-bed located in the Applied Chemistry Laboratory at KSC. In this report the RWGS process is first briefly described and an overview of Livingstone is given. Next, a Lyapunov-based approach for detecting and recovering from sensor failures, differing significantly from that used by Livingstone, is presented. In this new method, models used are in t e m of the defining differential equations of system components, thus differing from the qualitative, static models used by Livingstone. An easily computed scalar inequality constraint, expressed in terms of sensed system variables, is used to determine the existence of sensor failures. In the event of sensor failure, an observer/estimator is used for determining which sensors have failed. The theory underlying the new approach is developed. Finally, a recommendation is made to use the Lyapunov-based approach to complement the capability of Livingstone and to use this combination in the RWGS process.

  6. Accurately modeling Gaussian beam propagation in the context of Monte Carlo techniques

    NASA Astrophysics Data System (ADS)

    Hokr, Brett H.; Winblad, Aidan; Bixler, Joel N.; Elpers, Gabriel; Zollars, Byron; Scully, Marlan O.; Yakovlev, Vladislav V.; Thomas, Robert J.

    2016-03-01

    Monte Carlo simulations are widely considered to be the gold standard for studying the propagation of light in turbid media. However, traditional Monte Carlo methods fail to account for diffraction because they treat light as a particle. This results in converging beams focusing to a point instead of a diffraction limited spot, greatly effecting the accuracy of Monte Carlo simulations near the focal plane. Here, we present a technique capable of simulating a focusing beam in accordance to the rules of Gaussian optics, resulting in a diffraction limited focal spot. This technique can be easily implemented into any traditional Monte Carlo simulation allowing existing models to be converted to include accurate focusing geometries with minimal effort. We will present results for a focusing beam in a layered tissue model, demonstrating that for different scenarios the region of highest intensity, thus the greatest heating, can change from the surface to the focus. The ability to simulate accurate focusing geometries will greatly enhance the usefulness of Monte Carlo for countless applications, including studying laser tissue interactions in medical applications and light propagation through turbid media.

  7. Predicting the spatial distribution of soil profile in Adapazari/Turkey by artificial neural networks using CPT data

    NASA Astrophysics Data System (ADS)

    Arel, Ersin

    2012-06-01

    The infamous soils of Adapazari, Turkey, that failed extensively during the 46-s long magnitude 7.4 earthquake in 1999 have since been the subject of a research program. Boreholes, piezocone soundings and voluminous laboratory testing have enabled researchers to apply sophisticated methods to determine the soil profiles in the city using the existing database. This paper describes the use of the artificial neural network (ANN) model to predict the complex soil profiles of Adapazari, based on cone penetration test (CPT) results. More than 3236 field CPT readings have been collected from 117 soundings spread over an area of 26 km2. An attempt has been made to develop the ANN model using multilayer perceptrons trained with a feed-forward back-propagation algorithm. The results show that the ANN model is fairly accurate in predicting complex soil profiles. Soil identification using CPT test results has principally been based on the Robertson charts. Applying neural network systems using the chart offers a powerful and rapid route to reliable prediction of the soil profiles.

  8. [CI] and CO in local galaxies from the Beyond the Peak Project

    NASA Astrophysics Data System (ADS)

    Crocker, Alison F.; Pellegrini, E. W.; Smith, J. T.; Beyond The Peak Team

    2014-01-01

    From simple plane-parallel photodissociation region (PDR) models, neutral carbon ([CI]) is predicted to exist in a thin layer between C+ and CO on the surface of molecular clouds (e.g. (Hollenbach & Tielens 1999, Kaufman et al. 1999). However, observations of the Milky Way and the Magellanic Clouds indicate that [CI] may instead be a better tracer of the entire cold gas reservoir, often very well correlated with emission from 12CO(1-0) or 13CO(1-0) (e.g. Keene et al. 1996, Bolatto et al. 2000, Shimajiri et al. 2013). Here, we present the observed [CI] fluxes from the Beyond the Peak sample of 22 nearby galaxies observed with the Herschel FTS spectrometer. We first attempt to model all CO transitions and the [CI] lines as a single plane-parallel PDR, but this fails in all cases. Instead, a two-component PDR model is able to fit the CO SLED of nearly all galaxies. We investigate correlations of the [CI] fluxes and line ratio with properties of the cooler component determined from the PDR fits.

  9. A Feedback Control Model of Comprehensive Therapy for Treating Immunogenic Tumours

    NASA Astrophysics Data System (ADS)

    Tang, Biao; Xiao, Yanni; Tang, Sanyi; Cheke, Robert A.

    Surgery is the traditional method for treating cancers, but it often fails to cure patients for complex reasons so new therapeutic approaches that include both surgery and immunotherapy have recently been proposed. These have been shown to be effective, clinically, in inhibiting cancer cells while allowing retention of immunologic memory. This comprehensive strategy is guided by whether a population of tumour cells has or has not exceeded a threshold density. Conditions for successful control of tumours in an immune tumour system were modeled and the related dynamics were addressed. A mathematical model with state-dependent impulsive interventions is formulated to describe combinations of surgery with immunotherapy. By analyzing the properties of the Poincaré map, we examine the global dynamics of the immune tumour system with state-dependent feedback control, including the existence and stability of the semi-trivial order-1 periodic solution and the positive order-k periodic solution. The main results showed that surgery alone can only control the tumour size below a certain level while there is no immunologic memory. If comprehensive therapy involving combining surgery with immunotherapy is considered, then not only can the cancers be controlled below a certain level, but the immune system can also retain its activity. The existence of positive order-k periodic solutions implies that periodical therapy is needed to control the cancers. However, choosing the treatment frequency and the strength of the therapy remains challenging, and hence a strategy of individual-based therapy is suggested.

  10. Development of a GIS-based failure investigation system for highway soil slopes

    NASA Astrophysics Data System (ADS)

    Ramanathan, Raghav; Aydilek, Ahmet H.; Tanyu, Burak F.

    2015-06-01

    A framework for preparation of an early warning system was developed for Maryland, using a GIS database and a collective overlay of maps that highlight highway slopes susceptible to soil slides or slope failures in advance through spatial and statistical analysis. Data for existing soil slope failures was collected from geotechnical reports and field visits. A total of 48 slope failures were recorded and analyzed. Six factors, including event precipitation, geological formation, land cover, slope history, slope angle, and elevation were considered to affect highway soil slope stability. The observed trends indicate that precipitation and poor surface or subsurface drainage conditions are principal factors causing slope failures. 96% of the failed slopes have an open drainage section. A majority of the failed slopes lie in regions with relatively high event precipitation ( P>200 mm). 90% of the existing failures are surficial erosion type failures, and only 1 out of the 42 slope failures is deep rotational type failure. More than half of the analyzed slope failures have occurred in regions having low density land cover. 46% of failures are on slopes with slope angles between 20° and 30°. Influx of more data relating to failed slopes should give rise to more trends, and thus the developed slope management system will aid the state highway engineers in prudential budget allocation and prioritizing different remediation projects based on the literature reviewed on the principles, concepts, techniques, and methodology for slope instability evaluation (Leshchinsky et al., 2015).

  11. Improvement of preclinical animal models for autoimmune-mediated disorders via reverse translation of failed therapies.

    PubMed

    't Hart, Bert A; Jagessar, S Anwar; Kap, Yolanda S; Haanstra, Krista G; Philippens, Ingrid H C H M; Serguera, Che; Langermans, Jan; Vierboom, Michel

    2014-09-01

    The poor translational validity of autoimmune-mediated inflammatory disease (AIMID) models in inbred and specific pathogen-free (SPF) rodents underlies the high attrition of new treatments for the corresponding human disease. Experimental autoimmune encephalomyelitis (EAE) is a frequently used preclinical AIMID model. We discuss here how crucial information needed for the innovation of current preclinical models can be obtained from postclinical analysis of the nonhuman primate EAE model, highlighting the mechanistic reasons why some therapies fail and others succeed. These new insights can also help identify new targets for treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. IRLT: Integrating Reputation and Local Trust for Trustworthy Service Recommendation in Service-Oriented Social Networks

    PubMed Central

    Liu, Zhiquan; Ma, Jianfeng; Jiang, Zhongyuan; Miao, Yinbin; Gao, Cong

    2016-01-01

    With the prevalence of Social Networks (SNs) and services, plenty of trust models for Trustworthy Service Recommendation (TSR) in Service-oriented SNs (S-SNs) have been proposed. The reputation-based schemes usually do not contain user preferences and are vulnerable to unfair rating attacks. Meanwhile, the local trust-based schemes generally have low reliability or even fail to work when the trust path is too long or does not exist. Thus it is beneficial to integrate them for TSR in S-SNs. This work improves the state-of-the-art Combining Global and Local Trust (CGLT) scheme and proposes a novel Integrating Reputation and Local Trust (IRLT) model which mainly includes four modules, namely Service Recommendation Interface (SRI) module, Local Trust-based Trust Evaluation (LTTE) module, Reputation-based Trust Evaluation (RTE) module and Aggregation Trust Evaluation (ATE) module. Besides, a synthetic S-SN based on the famous Advogato dataset is deployed and the well-known Discount Cumulative Gain (DCG) metric is employed to measure the service recommendation performance of our IRLT model with comparing to that of the excellent CGLT model. The results illustrate that our IRLT model is slightly superior to the CGLT model in honest environment and significantly outperforms the CGLT model in terms of the robustness against unfair rating attacks. PMID:26963089

  13. IRLT: Integrating Reputation and Local Trust for Trustworthy Service Recommendation in Service-Oriented Social Networks.

    PubMed

    Liu, Zhiquan; Ma, Jianfeng; Jiang, Zhongyuan; Miao, Yinbin; Gao, Cong

    2016-01-01

    With the prevalence of Social Networks (SNs) and services, plenty of trust models for Trustworthy Service Recommendation (TSR) in Service-oriented SNs (S-SNs) have been proposed. The reputation-based schemes usually do not contain user preferences and are vulnerable to unfair rating attacks. Meanwhile, the local trust-based schemes generally have low reliability or even fail to work when the trust path is too long or does not exist. Thus it is beneficial to integrate them for TSR in S-SNs. This work improves the state-of-the-art Combining Global and Local Trust (CGLT) scheme and proposes a novel Integrating Reputation and Local Trust (IRLT) model which mainly includes four modules, namely Service Recommendation Interface (SRI) module, Local Trust-based Trust Evaluation (LTTE) module, Reputation-based Trust Evaluation (RTE) module and Aggregation Trust Evaluation (ATE) module. Besides, a synthetic S-SN based on the famous Advogato dataset is deployed and the well-known Discount Cumulative Gain (DCG) metric is employed to measure the service recommendation performance of our IRLT model with comparing to that of the excellent CGLT model. The results illustrate that our IRLT model is slightly superior to the CGLT model in honest environment and significantly outperforms the CGLT model in terms of the robustness against unfair rating attacks.

  14. Model Determined for Predicting Fatigue Lives of Metal Matrix Composites Under Mean Stresses

    NASA Technical Reports Server (NTRS)

    Lerch, Bradley

    1997-01-01

    Aircraft engine components invariably are subjected to mean stresses over and above the cyclic loads. In monolithic materials, it has been observed that tensile mean stresses are detrimental and compressive mean stresses are beneficial to fatigue life in comparison to a base of zero mean stress. Several mean stress models exist for monolithic metals, but each differ quantitatively in the extent to which detrimental or beneficial effects are ascribed. There have been limited attempts to apply these models to metal matrix composites. At the NASA Lewis Research Center, several mean stress models--the Smith-Watson- Topper, Walker, Normalized Goodman, and Soderberg models--were examined for applicability to this class of composite materials. The Soderberg approach, which normalizes the mean stress to a 0.02-percent yield strength, was shown to best represent the effect of mean stresses over the range covered. The other models varied significantly in their predictability and often failed to predict the composite behavior at very high tensile mean stresses. This work is the first to systematically demonstrate the influence of mean stresses on metal matrix composites and model their effects. Attention also was given to fatigue-cracking mechanisms in the Ti-15-3 matrix and to micromechanics analyses of mean stress effects.

  15. An analysis of the early-warning system in emerging markets for reducing the financial crisis

    NASA Astrophysics Data System (ADS)

    Shen, Xiangguang; Song, Xiaozhong

    2009-07-01

    The large number of financial crises in emerging markets over the past ten years has left many observers, both from academia and financial institutions, puzzled by an apparent lack of homogenous causal relations between endogenous economic variables and the bursting of large financial shocks. The frequency of financial crises in the last 20 years can be attributed to the lack of a comprehensive theory of financial regulation to guide policy makers. Existing theories fail to define the range of regulatory models, the causes of regulatory failure, and how to measure and prevent it. Faulty design of regulatory models, and the lack of ongoing performance monitoring incorporating early warning systems, is disrupting economic and social development. The main aim of this article is to propose an early warning system (EWS) which purposes issuing warning signal against the possible financial crisis in the emerging market, and makes the emerging market survived the first wave of the crisis be able to continue their operation in the following years.

  16. The intersection of aggregate-level lead exposure and crime.

    PubMed

    Boutwell, Brian B; Nelson, Erik J; Emo, Brett; Vaughn, Michael G; Schootman, Mario; Rosenfeld, Richard; Lewis, Roger

    2016-07-01

    Childhood lead exposure has been associated with criminal behavior later in life. The current study aimed to analyze the association between elevated blood lead levels (n=59,645) and crime occurrence (n=90,433) across census tracts within St. Louis, Missouri. Longitudinal ecological study. Saint Louis, Missouri. Blood lead levels. Violent, Non-violent, and total crime at the census tract level. Spatial statistical models were used to account for the spatial autocorrelation of the data. Greater lead exposure at the census-tract level was associated with increased violent, non-violent, and total crime. In addition, we examined whether non-additive effects existed in the data by testing for an interaction between lead exposure and concentrated disadvantage. Some evidence of a negative interaction emerged, however, it failed to reach traditional levels of statistical significance (supplementary models, however, revealed a similar negative interaction that was significant). More precise measurements of lead exposure in the aggregate, produced additional evidence that lead is a potent predictor of criminal outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Small Seed Black Hole Growth in Various Accretion Regimes

    NASA Astrophysics Data System (ADS)

    Gerling-Dunsmore, Hannalore J.; Hopkins, Philip F.

    2016-03-01

    Observational evidence indicates a population of super massive black holes (SMBHs) (~109 -1010M⊙) formed within 1 Gyr after the Big Bang. One proposed means of SMBH formation is accretion onto small seed black holes (BHs) (~ 100M⊙). However, the existence of SMBHs within 1 Gyr requires rapid growth, but conventional models of accretion fail to grow the seed BHs quickly enough. Super Eddington accretion (Ṁ >ṀEddington) may aid in improving growth efficiency. We study small seed BH growth via accretion in 3D, using the magneto-hydrodynamics+gravity code GIZMO. In particular, we consider a BH in a high density turbulent star-forming cloud, and ask whether or not the BH can capture sufficient gas to grow rapidly. We consider both Eddington-limited and super Eddington regimes, and resolve physics on scales from 0.1 pc to 1 kpc while including detailed models for stellar feedback physics, including stellar winds, supernovae, radiation pressure, and photo-ionization. We present results on the viability of different small seed BHs growing into SMBH candidates.

  18. Human motion analysis with detection of subpart deformations

    NASA Astrophysics Data System (ADS)

    Wang, Juhui; Lorette, Guy; Bouthemy, Patrick

    1992-06-01

    One essential constraint used in 3-D motion estimation from optical projections is the rigidity assumption. Because of muscle deformations in human motion, this rigidity requirement is often violated for some regions on the human body. Global methods usually fail to bring stable solutions. This paper presents a model-based approach to combating the effect of muscle deformations in human motion analysis. The approach developed is based on two main stages. In the first stage, the human body is partitioned into different areas, where each area is consistent with a general motion model (not necessarily corresponding to a physical existing motion pattern). In the second stage, the regions are eliminated under the hypothesis that they are not induced by a specific human motion pattern. Each hypothesis is generated by making use of specific knowledge about human motion. A global method is used to estimate the 3-D motion parameters in basis of valid segments. Experiments based on a cycling motion sequence are presented.

  19. DOES GARP REALLY FAIL MISERABLY? A RESPONSE TO STOCKMAN ET AL. (2006)

    EPA Science Inventory

    Stockman et al. (2006) found that ecological niche models built using DesktopGARP 'failed miserably' to predict trapdoor spider (genus Promyrmekiaphila) distributions in California. This apparent failure of GARP (Genetic Algorithm for Rule-Set Production) was actually a failure ...

  20. Legal Briefing: Mandated Reporters and Compulsory Reporting Duties.

    PubMed

    Pope, Thaddeus Mason

    2016-01-01

    This issue's "Legal Briefing" column, one product of a Greenwall Foundation grant, reviews recent developments concerning compulsory reporting duties. Most licensed clinicians in the United States are "mandated reporters." When these clinicians discover certain threats to the safety of patients or the public, they are legally required to report that information to specified government officials. Over the past year, several states have legislatively expanded the scope of these reporting duties. In other states, new court cases illustrate the vigorous enforcement of already existing duties. I have organized all these legal developments into the following eight categories: 1. Overview of Mandatory Reporting Duties 2. Controversy over the Benefits of Mandatory Reporting 3. New and Expanded Duties to Report 4. Criminal Penalties for Failing to Report 5. Civil Liability for Failing to Report 6. Disciplinary Penalties for Failing to Report 7. Legal Immunity for Good-Faith Reporting 8. Protection against Employers' Retaliation. Copyright 2016 The Journal of Clinical Ethics. All rights reserved.

  1. A Spectral Evaluation of Models Performances in Mediterranean Oak Woodlands

    NASA Astrophysics Data System (ADS)

    Vargas, R.; Baldocchi, D. D.; Abramowitz, G.; Carrara, A.; Correia, A.; Kobayashi, H.; Papale, D.; Pearson, D.; Pereira, J.; Piao, S.; Rambal, S.; Sonnentag, O.

    2009-12-01

    Ecosystem processes are influenced by climatic trends at multiple temporal scales including diel patterns and other mid-term climatic modes, such as interannual and seasonal variability. Because interactions between biophysical components of ecosystem processes are complex, it is important to test how models perform in frequency (e.g. hours, days, weeks, months, years) and time (i.e. day of the year) domains in addition to traditional tests of annual or monthly sums. Here we present a spectral evaluation using wavelet time series analysis of model performance in seven Mediterranean Oak Woodlands that encompass three deciduous and four evergreen sites. We tested the performance of five models (CABLE, ORCHIDEE, BEPS, Biome-BGC, and JULES) on measured variables of gross primary production (GPP) and evapotranspiration (ET). In general, model performance fails at intermediate periods (e.g. weeks to months) likely because these models do not represent the water pulse dynamics that influence GPP and ET at these Mediterranean systems. To improve the performance of a model it is critical to identify first where and when the model fails. Only by identifying where a model fails we can improve the model performance and use them as prognostic tools and to generate further hypotheses that can be tested by new experiments and measurements.

  2. Grammar Is Back, but When Will We Start Cooking?

    ERIC Educational Resources Information Center

    Vavra, Ed

    2003-01-01

    Suggests that the current "return" to grammar will fail unless educators can come to terms with definitions of fundamental grammatical concepts. Considers how educators cannot go back to teaching the traditional, because the traditional no longer exists. Argues that pedagogical grammar currently has too many cooks, all trying to prepare the same…

  3. Academic Freedom and Racial Injustice: South Africa's Former "Open Universities"

    ERIC Educational Resources Information Center

    Taylor, Y.; Taylor, R.

    2010-01-01

    The article critically re-interrogates three high profile cases of white racism at South Africa's former "open universities" to highlight the way in which existing debates around academic freedom fail to come to terms with questions of racial injustice after apartheid. The cases covered are the Makgoba affair at Wits, the Mamdani affair…

  4. Contraceptive Use Patterns across Teens' Sexual Relationships. Fact Sheet. Publication #2008-07

    ERIC Educational Resources Information Center

    Holcombe, Emily; Carrier, David; Manlove, Jennifer; Ryan, Suzanne

    2008-01-01

    Teens typically fail to use contraceptives consistently, which contributes to high rates of unintended pregnancy and sexually transmitted infections (STIs) among this age group. Existing research has focused primarily on how teens' own characteristics are related to contraceptive use, but has paid less attention to how the characteristics of…

  5. 29 CFR 30.6 - Existing lists of eligibles and public notice.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... than would reasonably be expected in view of the analysis described in § 30.4(e) shall discard all... to an apprentice job opportunity given by certified mail, return receipt requested. Applicants who... applicants who have been removed from the list or who have failed to respond to an apprenticeship job...

  6. A Framework for Semantic Group Formation in Education

    ERIC Educational Resources Information Center

    Ounnas, Asma; Davis, Hugh C.; Millard, David E.

    2009-01-01

    Collaboration has long been considered an effective approach to learning. However, forming optimal groups can be a time consuming and complex task. Different approaches have been developed to assist teachers allocate students to groups based on a set of constraints. However, existing tools often fail to assign some students to groups creating a…

  7. Clinical Investigation of a New Bulk Fill Composite Resin in the Restoration of Posterior Teeth

    ClinicalTrials.gov

    2017-09-14

    Dental Restoration Failure of Marginal Integrity; Dental Caries; Unrepairable Overhanging of Dental Restorative Materials; Poor Aesthetics of Existing Restoration; Secondary Dental Caries Associated With Failed or Defective Dental Restorations; Fractured Dental Restorative Materials Without Loss of Materials; Fracture of Dental Restorative Materials With Loss of Material

  8. When Using the Mean is Meaningless: Examples from Probability Theory and Cardiology.

    ERIC Educational Resources Information Center

    Liebovitch, Larry S.; Todorov, Angelo T.; Wood, Mark A.; Ellenbogen, Kenneth A.

    This chapter describes how the mean of fractal processes does not exist and is not a meaningful measure of some data. It discusses how important it is to stay open to the possibility that sometimes analytic techniques fail to satisfy some assumptions on which the mean is based. (KHR)

  9. Education and Its Limitations in the Maintenance of Peace in El Salvador.

    ERIC Educational Resources Information Center

    Moncada-Davidson, Lillian

    1995-01-01

    Points out weaknesses in Salvadoran government policies, which seek to reform public education and build human capital in the interests of long-term economic development but fail to address extreme poverty and social inequality. Suggests that support for existing grass-roots economic and educational projects would help the poor and thereby…

  10. Off Our Lawns and out of Our Basements: How We (Mis)Understand the Millennial Generation

    ERIC Educational Resources Information Center

    Mechler, Heather

    2013-01-01

    In this article, the author explores the existing research on the characteristics of Millennials within historical, social, and economic contexts. While many researchers have made claims about Millennials, they fail to consider how parenting styles, economic factors, historical events, and shifts in educational priorities may have created the…

  11. Revisiting Teacher Adoption of Technology: Research Implications and Recommendations for Successful Full Technology Integration

    ERIC Educational Resources Information Center

    Buckenmeyer, Janet

    2008-01-01

    Most teachers are still failing to fully integrate technologies in their classrooms to improve student achievement. If certain conditions exist, however, they are more likely to accept and use appropriate technologies in significant instructional ways. Relevant professional development and continuous access to needed resources are two significant…

  12. Taking an Inclusive Turn

    ERIC Educational Resources Information Center

    Ainscow, Mel

    2007-01-01

    This special edition of the journal focuses on what is, arguably, the biggest challenge facing education systems, that of developing practices that will reach out to those learners who are failed by existing arrangements. Specifically, the papers look at ways of using the views of stakeholders in order to move schools and other centres of learning…

  13. The Spaces and Places That Women Casual Academics (Often Fail To) Inhabit

    ERIC Educational Resources Information Center

    Crimmins, Gail

    2016-01-01

    This paper discusses a research project that aims to address the binary/irony of the central physical and teaching space that women casual academics inhabit within Australian universities, against their lack of presence in the existing discourses around higher education. The invisibility of women casual academics within the discourses around…

  14. Music and Music Education: Theory and Praxis for "Making a Difference"

    ERIC Educational Resources Information Center

    Regelski, Thomas A.

    2005-01-01

    The "music appreciation as contemplation" paradigm of traditional aesthetics and music education assumes that music exists to be contemplated for itself. The resulting distantiation of music and music education from life creates a legitimation crisis for music education. Failing to make a noteworthy musical difference for society, a politics of…

  15. Illinois Adult Literacy Failing the Workforce: Alternative Solution Needed. Policy Profiles.

    ERIC Educational Resources Information Center

    Banovetz, James M., Ed.

    According to the most recent National Adult Literacy Survey, nearly half of Illinois adults lack sufficient reading proficiency to ensure job success and advancement in 21st century workplaces. The Test of Adult Basic Education is currently used as a pretest/posttest in Illinois' existing adult basic education, adult secondary education, and…

  16. 5 CFR 831.613 - Election of insurable interest annuity.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... insurable interest annuity is cancelled if— (i) The retiree fails to qualify to receive the insurable... insurable interest is presumed to exist with— (i) The current spouse; (ii) The current same-sex domestic... same-sex domestic partner; (vi) A person to whom the employee or Member is engaged to be married, or a...

  17. 5 CFR 831.613 - Election of insurable interest annuity.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... insurable interest annuity is cancelled if— (i) The retiree fails to qualify to receive the insurable... insurable interest is presumed to exist with— (i) The current spouse; (ii) The current same-sex domestic... same-sex domestic partner; (vi) A person to whom the employee or Member is engaged to be married, or a...

  18. 75 FR 39168 - Special Regulations; Areas of the National Park System

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-08

    ... his death in 1972. During the closure, we completed four projects: installation of a new HVAC system... to either bulge or crack. The existing HVAC system installed in 1985 failed to maintain a stable...; Areas of the National Park System AGENCY: National Park Service. ACTION: Final Rule. SUMMARY: The...

  19. 49 CFR 223.11 - Requirements for existing locomotives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... be equipped with certified glazing in all locomotive cab windows after June 30, 1984. (d) Each... vandalism has a locomotive cab window that is broken or damaged so that the window fails to permit good... broken or damaged window is a part of the windshield of the locomotive cab, all of the forward and...

  20. Contrast-Marking Prosodic Emphasis in Williams Syndrome: Results of Detailed Phonetic Analysis

    ERIC Educational Resources Information Center

    Ito, Kiwako; Martens, Marilee A.

    2017-01-01

    Background: Past reports on the speech production of individuals with Williams syndrome (WS) suggest that their prosody is anomalous and may lead to challenges in spoken communication. While existing prosodic assessments confirm that individuals with WS fail to use prosodic emphasis to express contrast, those reports typically lack detailed…

  1. Silence in Teaching and Learning: Perspectives of a Nepalese Graduate Student

    ERIC Educational Resources Information Center

    Bista, Krishna

    2012-01-01

    The nature of silence is complex in any classroom with international or domestic students. Instructors sometimes fail to recognize that the classroom silence of foreign students is unlike their native counterparts. With an insider perspective, this article explores the concept of silence among international students by examining the existing body…

  2. A Threshold Theory of the Humor Response

    ERIC Educational Resources Information Center

    Epstein, Robert; Joker, Veronica R.

    2007-01-01

    The humor response has long been considered mysterious, and it is given relatively little attention in modern experimental psychology, in spite of the fact that numerous studies suggest that it has substantial benefits for mood and health. Existing theories of humor fail to account for some of the most basic humor phenomena. On most occasions when…

  3. A Mindtool-Based Collaborative Learning Approach to Enhancing Students' Innovative Performance in Management Courses

    ERIC Educational Resources Information Center

    Wu, Chih-Hsiang; Hwang, Gwo-Jen; Kuo, Fan-Ray; Huang, Iwen

    2013-01-01

    Educators have indicated that creative teaching is the most important educational activity; nevertheless, most existing education systems fail to engage students in effective creative tasks. To address this issue, this study proposes a mind map based collaborative learning approach for supporting creative learning activities and enhancing…

  4. Creating Peaceful and Effective Schools through a Culture of Care

    ERIC Educational Resources Information Center

    Cavanagh, Tom; Macfarlane, Angus; Glynn, Ted; Macfarlane, Sonja

    2012-01-01

    Many schools in New Zealand, the USA, and elsewhere, are searching for ways to respond positively to the educational achievement disparities that exist between majority culture students and students from minority ethnic and cultural communities. Most of the approaches and strategies that have been implemented to date have either failed, or had…

  5. Foundations of Change for the Scholar-Practitioner Leader

    ERIC Educational Resources Information Center

    Thompson, Donna R.

    2010-01-01

    Change is a fact of life, and educational reform is replete with change. However, cosmetic changes fail to bring about real improvement. Rather than remodel the existing concept of public education, leaders must create a new one. The schools must be recultured. The change leader must build trust with open communication supporting followers through…

  6. Exploring the Impact of Early Decisions in Variable Ordering for Constraint Satisfaction Problems.

    PubMed

    Ortiz-Bayliss, José Carlos; Amaya, Ivan; Conant-Pablos, Santiago Enrique; Terashima-Marín, Hugo

    2018-01-01

    When solving constraint satisfaction problems (CSPs), it is a common practice to rely on heuristics to decide which variable should be instantiated at each stage of the search. But, this ordering influences the search cost. Even so, and to the best of our knowledge, no earlier work has dealt with how first variable orderings affect the overall cost. In this paper, we explore the cost of finding high-quality orderings of variables within constraint satisfaction problems. We also study differences among the orderings produced by some commonly used heuristics and the way bad first decisions affect the search cost. One of the most important findings of this work confirms the paramount importance of first decisions. Another one is the evidence that many of the existing variable ordering heuristics fail to appropriately select the first variable to instantiate. Another one is the evidence that many of the existing variable ordering heuristics fail to appropriately select the first variable to instantiate. We propose a simple method to improve early decisions of heuristics. By using it, performance of heuristics increases.

  7. Exploring the Impact of Early Decisions in Variable Ordering for Constraint Satisfaction Problems

    PubMed Central

    Amaya, Ivan

    2018-01-01

    When solving constraint satisfaction problems (CSPs), it is a common practice to rely on heuristics to decide which variable should be instantiated at each stage of the search. But, this ordering influences the search cost. Even so, and to the best of our knowledge, no earlier work has dealt with how first variable orderings affect the overall cost. In this paper, we explore the cost of finding high-quality orderings of variables within constraint satisfaction problems. We also study differences among the orderings produced by some commonly used heuristics and the way bad first decisions affect the search cost. One of the most important findings of this work confirms the paramount importance of first decisions. Another one is the evidence that many of the existing variable ordering heuristics fail to appropriately select the first variable to instantiate. Another one is the evidence that many of the existing variable ordering heuristics fail to appropriately select the first variable to instantiate. We propose a simple method to improve early decisions of heuristics. By using it, performance of heuristics increases. PMID:29681923

  8. Driving and off-road impairments underlying failure on road testing in Parkinson's disease.

    PubMed

    Devos, Hannes; Vandenberghe, Wim; Tant, Mark; Akinwuntan, Abiodun E; De Weerdt, Willy; Nieuwboer, Alice; Uc, Ergun Y

    2013-12-01

    Parkinson's disease (PD) affects driving ability. We aimed to determine the most critical impairments in specific road skills and in clinical characteristics leading to failure on a road test in PD. In this cross-sectional study, certified driving assessment experts evaluated specific driving skills in 104 active, licensed drivers with PD using a standardized, on-road checklist and issued a global decision of pass/fail. Participants also completed an off-road evaluation assessing demographic features, disease characteristics, motor function, vision, and cognition. The most important driving skills and off-road predictors of the pass/fail outcome were identified using multivariate stepwise regression analyses. Eighty-six (65%) passed and 36 (35%) failed the on-road driving evaluation. Persons who failed performed worse on all on-road items. When adjusted for age and gender, poor performances on lateral positioning at low speed, speed adaptations at high speed, and left turning maneuvers yielded the best model that determined the pass/fail decision (R(2) = 0.56). The fail group performed poorer on all motor, visual, and cognitive tests. Measures of visual scanning, motor severity, PD subtype, visual acuity, executive functions, and divided attention were independent predictors of pass/fail decisions in the multivariate model (R(2) = 0.60). Our study demonstrated that failure on a road test in PD is determined by impairments in specific driving skills and associated with deficits in motor, visual, executive, and visuospatial functions. These findings point to specific driving and off-road impairments that can be targeted in multimodal rehabilitation programs for drivers with PD. © 2013 Movement Disorder Society.

  9. Field evidence for control of quarrying by rock bridges in jointed bedrock

    NASA Astrophysics Data System (ADS)

    Hooyer, T. S.; Cohen, D. O.; Iverson, N. R.

    2011-12-01

    Quarrying is generally thought to be the most important mechanism by which glaciers erode bedrock. In quarrying models it is assumed that slow, subcritical, growth of pre-existing cracks rate-limits the process and occurs where there are large stress differences in the bed, such as near rock bumps where ice separates from the bed to form water-filled cavities. Owing to the direction of principal stresses in rocks associated with sliding and resultant cavity formation, models predict that quarrying will occur along cracks oriented perpendicular to the ice flow direction or parallel to zones of ice-bed contact. Preglacial cracks in rocks will tend to propagate mainly downward, and in sedimentary or some metamorphic rocks will merge with bedding planes, thereby helping to isolate rock blocks for dislodgement. In contrast to these model assumptions, new measurements of quarried surface orientations in the deglaciated forefield of nine glaciers in Switzerland and Canada indicate a strong correlation between orientations of pre-existing joints and quarried bedrock surfaces, independent of ice flow direction or ice-water contact lines. The strong correlation persists across all rock types, and rocks devoid of major joints lack quarried surfaces. We propose a new conceptual model of quarrying that idealizes the bedrock as a series of blocks separated by discontinuous preglacial joints containing intact rock bridges. Bridges concentrate stress differences caused by normal and shear forces acting at the rock surface. Failure of bridges is caused by slow subcritical crack growth enhanced by water pressure fluctuations. To lend credibility to this new model, we show field evidence of failed rock bridges in quarried surfaces and of rib marks on plumose structures that we interpret as arrest fracture fronts due to transient subglacial water-pressure fluctuations.

  10. Active-standby servovalue/actuator development

    NASA Technical Reports Server (NTRS)

    Masm, R. K.

    1973-01-01

    A redundant, fail/operate fail/fixed servoactuator was constructed and tested along with electronic models of a servovalve. It was found that a torque motor switch is satisfactory for the space shuttle main engine hydraulic actuation system, and that this system provides an effective failure monitoring technique.

  11. Predicting the velocity and azimuth of fragments generated by the range destruction or random failure of rocket casings and tankage

    NASA Astrophysics Data System (ADS)

    Eck, M.; Mukunda, M.

    The proliferation of space vehicle launch sites and the projected utilization of these facilities portends an increase in the number of on-pad, ascent, and on-orbit solid-rocket motor (SRM) casings and liquid-rocket tanks which will randomly fail or will fail from range destruct actions. Beyond the obvious safety implications, these failures may have serious resource implications for mission system and facility planners. SRM-casing failures and liquid-rocket tankage failures result in the generation of large, high velocity fragments which may be serious threats to the safety of launch support personnel if proper bunkers and exclusion areas are not provided. In addition, these fragments may be indirect threats to the general public's safety if they encounter hazardous spacecraft payloads which have not been designed to withstand shrapnel of this caliber. They may also become threats to other spacecraft if, by failing on-orbit, they add to the ever increasing space-junk collision cross-section. Most prior attempts to assess the velocity of fragments from failed SRM casings have simply assigned the available chamber impulse to available casing and fuel mass and solved the resulting momentum balance for velocity. This method may predict a fragment velocity which is high or low by a factor of two depending on the ratio of fuel to casing mass extant at the time of failure. Recognizing the limitations of existing methods, the authors devised an analytical approach which properly partitions the available impulse to each major system-mass component. This approach uses the Physics International developed PISCES code to couple the forces generated by an Eulerian modeled gas flow field to a Lagrangian modeled fuel and casing system. The details of a predictive analytical modeling process as well as the development of normalized relations for momentum partition as a function of SRM burn time and initial geometry are discussed in this paper. Methods for applying similar modeling techniques to liquid-tankage-over-pressure failures are also discussed. These methods have been calibrated against observed SRM ascent failures and on-orbit tankage failures. Casing-quadrant sized fragments with velocities exceeding 100 m/s resulted from Titan 34D-SRM range destruct actions at 10 s mission elapsed time (MET). Casing-quadrant sized fragments with velocities of approx. 200 m/s resulted from STS-SRM range destruct actions at 110 s MET. Similar sized fragments for Ariane third stage and Delta second stage tankage were predicted to have maximum velocities of 260 and 480 m/s respectively. Good agreement was found between the predictions and observations for five specific events and it was concluded that the methods developed have good potential for use in predicting the fragmentation process of a number of generically similar casing and tankage systems.

  12. Exploring "patient-centered" hospitals: a systematic review to understand change.

    PubMed

    Gabutti, Irene; Mascia, Daniele; Cicchetti, Americo

    2017-05-22

    The healthcare scenario in developed countries is changing deeply: patients, who are frequently affected by multi-pathological chronic conditions, have risen their expectations. Simultaneously, there exist dramatic financial pressures which require healthcare organizations to provide more and better services with equal (or decreasing) resources. In response to these challenges, hospitals are facing radical transformations by bridging, redesigning and engaging their organization and staff. This study has the ambitious aim to shed light and clearly label the trends of change hospitals are enhancing in developed economies, in order to fully understand the presence of common trends and which organizational models and features are inspiring the most innovative organizations. The purpose is to make stock of what is known in the field of hospital organization about how hospitals are changing, as well as of how such change may be implemented effectively through managerial tools. To do so the methodology adopted integrates a systematic literature review to a wider engaged research approach. Evidence suggests that the three main pillars of change of the system are given by the progressive patient care model, the patient-centered approach and the lean approach. However, there emerge a number of gaps in what is known about how to exploit drivers of change and their effects. This study confirms that efforts in literature are concentrated in analyzing circumscribed experiences in the implementation of new models and approaches, failing therefore to extend the analysis at the organizational and inter-organizational level in order to legitimately draw consequences to be generalized. There seem to be a number of "gaps" in what is known about how to exploit drivers of change and their effects, suggesting that the research approach privileged till now fails in providing a clear guidance to policy makers and to organizations' management on how to concretely and effectively implement new organizational models.

  13. A Hybrid Approach to Data Assimilation for Reconstructing the Evolution of Mantle Dynamics

    NASA Astrophysics Data System (ADS)

    Zhou, Quan; Liu, Lijun

    2017-11-01

    Quantifying past mantle dynamic processes represents a major challenge in understanding the temporal evolution of the solid earth. Mantle convection modeling with data assimilation is one of the most powerful tools to investigate the dynamics of plate subduction and mantle convection. Although various data assimilation methods, both forward and inverse, have been created, these methods all have limitations in their capabilities to represent the real earth. Pure forward models tend to miss important mantle structures due to the incorrect initial condition and thus may lead to incorrect mantle evolution. In contrast, pure tomography-based models cannot effectively resolve the fine slab structure and would fail to predict important subduction-zone dynamic processes. Here we propose a hybrid data assimilation approach that combines the unique power of the sequential and adjoint algorithms, which can properly capture the detailed evolution of the downgoing slab and the tomographically constrained mantle structures, respectively. We apply this new method to reconstructing mantle dynamics below the western U.S. while considering large lateral viscosity variations. By comparing this result with those from several existing data assimilation methods, we demonstrate that the hybrid modeling approach recovers the realistic 4-D mantle dynamics the best.

  14. Approaches to biofilm-associated infections: the need for standardized and relevant biofilm methods for clinical applications.

    PubMed

    Malone, Matthew; Goeres, Darla M; Gosbell, Iain; Vickery, Karen; Jensen, Slade; Stoodley, Paul

    2017-02-01

    The concept of biofilms in human health and disease is now widely accepted as cause of chronic infection. Typically, biofilms show remarkable tolerance to many forms of treatments and the host immune response. This has led to vast increase in research to identify new (and sometimes old) anti-biofilm strategies that demonstrate effectiveness against these tolerant phenotypes. Areas covered: Unfortunately, a standardized methodological approach of biofilm models has not been adopted leading to a large disparity between testing conditions. This has made it almost impossible to compare data across multiple laboratories, leaving large gaps in the evidence. Furthermore, many biofilm models testing anti-biofilm strategies aimed at the medical arena have not considered the matter of relevance to an intended application. This may explain why some in vitro models based on methodological designs that do not consider relevance to an intended application fail when applied in vivo at the clinical level. Expert commentary: This review will explore the issues that need to be considered in developing performance standards for anti-biofilm therapeutics and provide a rationale for the need to standardize models/methods that are clinically relevant. We also provide some rational as to why no standards currently exist.

  15. An approximate block Newton method for coupled iterations of nonlinear solvers: Theory and conjugate heat transfer applications

    NASA Astrophysics Data System (ADS)

    Yeckel, Andrew; Lun, Lisa; Derby, Jeffrey J.

    2009-12-01

    A new, approximate block Newton (ABN) method is derived and tested for the coupled solution of nonlinear models, each of which is treated as a modular, black box. Such an approach is motivated by a desire to maintain software flexibility without sacrificing solution efficiency or robustness. Though block Newton methods of similar type have been proposed and studied, we present a unique derivation and use it to sort out some of the more confusing points in the literature. In particular, we show that our ABN method behaves like a Newton iteration preconditioned by an inexact Newton solver derived from subproblem Jacobians. The method is demonstrated on several conjugate heat transfer problems modeled after melt crystal growth processes. These problems are represented by partitioned spatial regions, each modeled by independent heat transfer codes and linked by temperature and flux matching conditions at the boundaries common to the partitions. Whereas a typical block Gauss-Seidel iteration fails about half the time for the model problem, quadratic convergence is achieved by the ABN method under all conditions studied here. Additional performance advantages over existing methods are demonstrated and discussed.

  16. A review of anisotropic conductivity models of brain white matter based on diffusion tensor imaging.

    PubMed

    Wu, Zhanxiong; Liu, Yang; Hong, Ming; Yu, Xiaohui

    2018-06-01

    The conductivity of brain tissues is not only essential for electromagnetic source estimation (ESI), but also a key reflector of the brain functional changes. Different from the other brain tissues, the conductivity of whiter matter (WM) is highly anisotropic and a tensor is needed to describe it. The traditional electrical property imaging methods, such as electrical impedance tomography (EIT) and magnetic resonance electrical impedance tomography (MREIT), usually fail to image the anisotropic conductivity tensor of WM with high spatial resolution. The diffusion tensor imaging (DTI) is a newly developed technique that can fulfill this purpose. This paper reviews the existing anisotropic conductivity models of WM based on the DTI and discusses their advantages and disadvantages, as well as identifies opportunities for future research on this subject. It is crucial to obtain the linear conversion coefficient between the eigenvalues of anisotropic conductivity tensor and diffusion tensor, since they share the same eigenvectors. We conclude that the electrochemical model is suitable for ESI analysis because the conversion coefficient can be directly obtained from the concentration of ions in extracellular liquid and that the volume fraction model is appropriate to study the influence of WM structural changes on electrical conductivity. Graphical abstract ᅟ.

  17. Sparse kernel methods for high-dimensional survival data.

    PubMed

    Evers, Ludger; Messow, Claudia-Martina

    2008-07-15

    Sparse kernel methods like support vector machines (SVM) have been applied with great success to classification and (standard) regression settings. Existing support vector classification and regression techniques however are not suitable for partly censored survival data, which are typically analysed using Cox's proportional hazards model. As the partial likelihood of the proportional hazards model only depends on the covariates through inner products, it can be 'kernelized'. The kernelized proportional hazards model however yields a solution that is dense, i.e. the solution depends on all observations. One of the key features of an SVM is that it yields a sparse solution, depending only on a small fraction of the training data. We propose two methods. One is based on a geometric idea, where-akin to support vector classification-the margin between the failed observation and the observations currently at risk is maximised. The other approach is based on obtaining a sparse model by adding observations one after another akin to the Import Vector Machine (IVM). Data examples studied suggest that both methods can outperform competing approaches. Software is available under the GNU Public License as an R package and can be obtained from the first author's website http://www.maths.bris.ac.uk/~maxle/software.html.

  18. A Hybrid Forward-Adjoint Data Assimilation Method for Reconstructing the Temporal Evolution of Mantle Dynamics

    NASA Astrophysics Data System (ADS)

    Zhou, Q.; Liu, L.

    2017-12-01

    Quantifying past mantle dynamic processes represents a major challenge in understanding the temporal evolution of the solid earth. Mantle convection modeling with data assimilation is one of the most powerful tools to investigate the dynamics of plate subduction and mantle convection. Although various data assimilation methods, both forward and inverse, have been created, these methods all have limitations in their capabilities to represent the real earth. Pure forward models tend to miss important mantle structures due to the incorrect initial condition and thus may lead to incorrect mantle evolution. In contrast, pure tomography-based models cannot effectively resolve the fine slab structure and would fail to predict important subduction-zone dynamic processes. Here we propose a hybrid data assimilation method that combines the unique power of the sequential and adjoint algorithms, which can properly capture the detailed evolution of the downgoing slab and the tomographically constrained mantle structures, respectively. We apply this new method to reconstructing mantle dynamics below the western U.S. while considering large lateral viscosity variations. By comparing this result with those from several existing data assimilation methods, we demonstrate that the hybrid modeling approach recovers the realistic 4-D mantle dynamics to the best.

  19. Tendon healing in a bone tunnel. Part I: Biomechanical results after biodegradable interference fit fixation in a model of anterior cruciate ligament reconstruction in sheep.

    PubMed

    Weiler, Andreas; Peine, Ricarda; Pashmineh-Azar, Alireza; Abel, Clemens; Südkamp, Norbert P; Hoffmann, Reinhard F G

    2002-02-01

    Interference fit fixation of soft-tissue grafts has recently raised strong interest because it allows for anatomic graft fixation that may increase knee stability and graft isometry. Although clinical data show promising results, no data exist on how tendon healing progresses using this fixation. The purpose of the present study was to investigate anterior cruciate ligament (ACL) reconstruction biomechanically using direct tendon-to-bone interference fit fixation with biodegradable interference screws in a sheep model. Animal study. Thirty-five mature sheep underwent ACL reconstruction with an autologous Achilles tendon split graft. Grafts were directly fixed with poly-(D,L-lactide) interference screws. Animals were euthanized after 6, 9, 12, 24, and 52 weeks and standard biomechanical evaluations were performed. All grafts at time zero failed by pullout from the bone tunnel, whereas grafts at 6 and 9 weeks failed intraligamentously at the screw insertion site. At 24 and 52 weeks, grafts failed by osteocartilaginous avulsion. At 24 weeks, interference screws were macroscopically degraded. At 6 and 9 weeks tensile stress was only 6.8% and 9.6%, respectively, of the graft tissue at time zero. At 52 weeks, tensile stress of the reconstruction equaled 63.8% and 47.3% of the Achilles tendon graft at time zero and the native ACL, respectively. A complete restitution of anterior-posterior drawer displacement was found at 52 weeks compared with the time-zero reconstruction. It was found that over the whole healing period the graft fixation proved not to be the weak link of the reconstruction and that direct interference fit fixation withstands loads without motion restriction in the present animal model. The weak link during the early healing stage was the graft at its tunnel entrance site, leading to a critical decrease in mechanical properties. This finding indicates that interference fit fixation of a soft-tissue graft may additionally alter the mechanical properties of the graft in the early remodeling stage because of a possible tissue compromise at the screw insertion site. Although mechanical properties of the graft tissue had not returned to normal at 1 year compared with those at time zero, knee stability had returned to normal at that time. There was no graft pullout after 24 weeks, indicating that screw degradation does not compromise graft fixation.

  20. Closing the loop: modelling of heart failure progression from health to end-stage using a meta-analysis of left ventricular pressure-volume loops.

    PubMed

    Warriner, David R; Brown, Alistair G; Varma, Susheel; Sheridan, Paul J; Lawford, Patricia; Hose, David R; Al-Mohammad, Abdallah; Shi, Yubing

    2014-01-01

    The American Heart Association (AHA)/American College of Cardiology (ACC) guidelines for the classification of heart failure (HF) are descriptive but lack precise and objective measures which would assist in categorising such patients. Our aim was two fold, firstly to demonstrate quantitatively the progression of HF through each stage using a meta-analysis of existing left ventricular (LV) pressure-volume (PV) loop data and secondly use the LV PV loop data to create stage specific HF models. A literature search yielded 31 papers with PV data, representing over 200 patients in different stages of HF. The raw pressure and volume data were extracted from the papers using a digitising software package and the means were calculated. The data demonstrated that, as HF progressed, stroke volume (SV), ejection fraction (EF%) decreased while LV volumes increased. A 2-element lumped parameter model was employed to model the mean loops and the error was calculated between the loops, demonstrating close fit between the loops. The only parameter that was consistently and statistically different across all the stages was the elastance (Emax). For the first time, the authors have created a visual and quantitative representation of the AHA/ACC stages of LVSD-HF, from normal to end-stage. The study demonstrates that robust, load-independent and reproducible parameters, such as elastance, can be used to categorise and model HF, complementing the existing classification. The modelled PV loops establish previously unknown physiological parameters for each AHA/ACC stage of LVSD-HF, such as LV elastance and highlight that it this parameter alone, in lumped parameter models, that determines the severity of HF. Such information will enable cardiovascular modellers with an interest in HF, to create more accurate models of the heart as it fails.

  1. Cross-disciplinary links in environmental systems science: Current state and claimed needs identified in a meta-review of process models.

    PubMed

    Ayllón, Daniel; Grimm, Volker; Attinger, Sabine; Hauhs, Michael; Simmer, Clemens; Vereecken, Harry; Lischeid, Gunnar

    2018-05-01

    Terrestrial environmental systems are characterised by numerous feedback links between their different compartments. However, scientific research is organized into disciplines that focus on processes within the respective compartments rather than on interdisciplinary links. Major feedback mechanisms between compartments might therefore have been systematically overlooked so far. Without identifying these gaps, initiatives on future comprehensive environmental monitoring schemes and experimental platforms might fail. We performed a comprehensive overview of feedbacks between compartments currently represented in environmental sciences and explores to what degree missing links have already been acknowledged in the literature. We focused on process models as they can be regarded as repositories of scientific knowledge that compile findings of numerous single studies. In total, 118 simulation models from 23 model types were analysed. Missing processes linking different environmental compartments were identified based on a meta-review of 346 published reviews, model intercomparison studies, and model descriptions. Eight disciplines of environmental sciences were considered and 396 linking processes were identified and ascribed to the physical, chemical or biological domain. There were significant differences between model types and scientific disciplines regarding implemented interdisciplinary links. The most wide-spread interdisciplinary links were between physical processes in meteorology, hydrology and soil science that drive or set the boundary conditions for other processes (e.g., ecological processes). In contrast, most chemical and biological processes were restricted to links within the same compartment. Integration of multiple environmental compartments and interdisciplinary knowledge was scarce in most model types. There was a strong bias of suggested future research foci and model extensions towards reinforcing existing interdisciplinary knowledge rather than to open up new interdisciplinary pathways. No clear pattern across disciplines exists with respect to suggested future research efforts. There is no evidence that environmental research would clearly converge towards more integrated approaches or towards an overarching environmental systems theory. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Formation of calcareous nodules in loess-paleosol sequences: Reviews of existing models with a proposed new "per evapotranspiration model"

    NASA Astrophysics Data System (ADS)

    Li, Yanrong; Zhang, Weiwei; Aydin, Adnan; Deng, Xiaohong

    2018-04-01

    Loess is a product of aeolian deposition during Quaternary glaciation cycles. Loess-paleosol sequences are rich in calcareous nodules (CNs). In the literature, two models are widely cited for the formation of CNs, namely "per descendum" and "per ascendum". However, there has been no direct testing or monitoring to support either of these contradictory models. This paper reviews a large number of multidisciplinary literature to evaluate the consistency, reliability and rationality of these two models. Three main conclusions are drawn: (1) the causative factors (variation of pH value along loess-paleosol sequence, decrease of CO2 partial pressure, and reduction of solvent water) that are used to support the per descendum model do not completely explain the supersaturation of infiltration solution with CaCO3, thereby making this model questionable; (2) the per ascendum model explains the formation of CNs along narrow horizons through upward evaporation; however, it fails to produce sporadic distributions and irregular shapes of nodules on loess slope faces and the frequent appearance of nodules around plant roots. In order to reconcile these deficiencies, we conducted an extensive field survey in various parts of Shanxi province. Based on this new set of observations, it was concluded that the "per ascendum" model can be extended to explain all occurrences of CNs. This extended model is called "per evapotranspiration".

  3. Of mice and men: how animal models advance our understanding of T-cell function in RA.

    PubMed

    Kobezda, Tamás; Ghassemi-Nejad, Sheida; Mikecz, Katalin; Glant, Tibor T; Szekanecz, Zoltán

    2014-03-01

    The involvement of autoreactive T cells in the pathogenesis of rheumatoid arthritis (RA) as well as in autoimmune animal models of arthritis has been well established; however, unanswered questions, such as the role of joint-homing T cells, remain. Animal models of arthritis are superb experimental tools in demonstrating how T cells trigger joint inflammation, and thus can help to further our knowledge of disease mechanisms and potential therapies. In this Review, we discuss the similarities and differences in T-cell subsets and functions between RA and mouse arthritis models. For example, various T-cell subsets are involved in both human and mouse arthritis, but differences might exist in the cytokine regulation and plasticity of these cells. With regard to joint-homing T cells, an abundance of synovial T cells is present in humans compared with mice. On the other hand, local expansion of type 17 T-helper (TH17) cells is observed in some animal models, but not in RA. Finally, whereas T-cell depletion therapy essentially failed in RA, antibody targeting of T cells can work, at least preventatively, in most arthritis models. Clearly, additional human and animal studies are needed to fill the gap in our understanding of the specific contribution of T-cell subsets to arthritis in mice and men.

  4. NAN--a national voice for community-based services to persons with AIDS.

    PubMed Central

    Kawata, P A; Andriote, J M

    1988-01-01

    Because of the variety of needs engendered by AIDS, a broadbased response to the epidemic is warranted. The traditional medical model, with its emphasis on inpatient hospital care, is expensive and fails to address other needs of people with AIDS (PWAs). This paper outlines an alternative model: the community-based response, or continuum-of-care model. It builds on earlier community models of an integrated network of service providers who can better meet a range of needs of PWAs outside the hospital. Although the model may include a designated hospital AIDS unit that supplies inpatient services, the continuum-of-care model incorporates other nonacute and psychosocial services offered through community-based providers, and these services rely to a large extent on volunteers. Nationwide, more than 400 community-based AIDS service organizations have been formed in response to the growing AIDS epidemic, or have evolved from existing organizations. The National AIDS Network (NAN) was formed in 1985 by five such organizations to represent at the national level the vision of community-based AIDS care. As the nexus for a national community-based response, NAN acts as a conduit for service providers to share experience as well as a clearinghouse for information and programs. PMID:3131822

  5. On the validity of the use of a localized approximation for helical beams. I. Formal aspects

    NASA Astrophysics Data System (ADS)

    Gouesbet, Gérard; André Ambrosio, Leonardo

    2018-03-01

    The description of an electromagnetic beam for use in light scattering theories may be carried out by using an expansion over vector spherical wave functions with expansion coefficients expressed in terms of Beam Shape Coefficients (BSCs). A celebrated method to evaluate these BSCs has been the use of localized approximations (with several existing variants). We recently established that the use of any existing localized approximation is of limited validity in the case of Bessel and Mathieu beams. In the present paper, we address a warning against the use of any existing localized approximation in the case of helical beams. More specifically, we demonstrate that a procedure used to validate any existing localized approximation fails in the case of helical beams. Numerical computations in a companion paper will confirm that existing localized approximations are of limited validity in the case of helical beams.

  6. A study of social interaction and teamwork in reformed physics laboratories

    NASA Astrophysics Data System (ADS)

    Gresser, Paul W.

    It is widely accepted that, for many students, learning can be accomplished most effectively through social interaction with peers, and there have been many successes in using the group environment to improve learning in a variety of classroom settings. What is not well understood, however, are the dynamics of student groups, specifically how the students collectively apprehend the subject matter and share the mental workload. This research examines recent developments of theoretical tools for describing the cognitive states of individual students: associational patterns such as epistemic games and cultural structures such as epistemological framing. Observing small group interaction in authentic classroom situations (labs, tutorials, problem solving) suggests that these tools could be effective in describing these interactions. Though conventional wisdom tells us that groups may succeed where individuals fail, there are many reasons why group work may also run into difficulties, such as a lack or imbalance of knowledge, an inappropriate mix of learning styles, or a destructive power arrangement. This research explores whether or not inconsistent epistemological framing among group members can also be a cause of group failure. Case studies of group interaction in the laboratory reveal evidence of successful groups employing common framing, and unsuccessful groups failing from lack of a shared frame. This study was conducted in a large introductory algebra-based physics course at the University of Maryland, College Park, in a laboratory designed specifically to foster increased student interaction and cooperation. Videotape studies of this environment reveal that productive lab groups coordinate their efforts through a number of locally coherent knowledge-building activities, which are described through the framework of epistemic games. The existence of these epistemic games makes it possible for many students to participate in cognitive activities without a complete shared understanding of the specific activity's goal. Also examined is the role that social interaction plays in initiating, negotiating, and carrying out these epistemic games. This behavior is illustrated through the model of distributed cognition. An attempt is made to analyze this group activity using Tuckman's stage model, which is a prominent description of group development within educational psychology. However, the shortcomings of this model in dealing with specific cognitive tasks lead us to seek another explanation. The model used in this research seeks to expand existing cognitive tools into the realm of social interaction. In doing so, we can see that successful groups approach tasks in the lab by negotiating a shared frame of understanding. Using the findings from these case studies, recommendations are made concerning the teaching of introductory physics laboratory courses.

  7. 40 CFR 86.098-30 - Certification.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., and for 1985 and Later Model Year New Gasoline Fueled, Natural Gas-Fueled, Liquefied Petroleum Gas... with the selection criteria employed in selecting the failed vehicle, a new emission data vehicle which... selected in accordance with the selection criteria employed in selecting the failed vehicle, then two or...

  8. 40 CFR 86.098-30 - Certification.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., and for 1985 and Later Model Year New Gasoline Fueled, Natural Gas-Fueled, Liquefied Petroleum Gas... with the selection criteria employed in selecting the failed vehicle, a new emission data vehicle which... selected in accordance with the selection criteria employed in selecting the failed vehicle, then two or...

  9. The Frank-Starling mechanism involves deceleration of cross-bridge kinetics and is preserved in failing human right ventricular myocardium.

    PubMed

    Milani-Nejad, Nima; Canan, Benjamin D; Elnakish, Mohammad T; Davis, Jonathan P; Chung, Jae-Hoon; Fedorov, Vadim V; Binkley, Philip F; Higgins, Robert S D; Kilic, Ahmet; Mohler, Peter J; Janssen, Paul M L

    2015-12-15

    Cross-bridge cycling rate is an important determinant of cardiac output, and its alteration can potentially contribute to reduced output in heart failure patients. Additionally, animal studies suggest that this rate can be regulated by muscle length. The purpose of this study was to investigate cross-bridge cycling rate and its regulation by muscle length under near-physiological conditions in intact right ventricular muscles of nonfailing and failing human hearts. We acquired freshly explanted nonfailing (n = 9) and failing (n = 10) human hearts. All experiments were performed on intact right ventricular cardiac trabeculae (n = 40) at physiological temperature and near the normal heart rate range. The failing myocardium showed the typical heart failure phenotype: a negative force-frequency relationship and β-adrenergic desensitization (P < 0.05), indicating the expected pathological myocardium in the right ventricles. We found that there exists a length-dependent regulation of cross-bridge cycling kinetics in human myocardium. Decreasing muscle length accelerated the rate of cross-bridge reattachment (ktr) in both nonfailing and failing myocardium (P < 0.05) equally; there were no major differences between nonfailing and failing myocardium at each respective length (P > 0.05), indicating that this regulatory mechanism is preserved in heart failure. Length-dependent assessment of twitch kinetics mirrored these findings; normalized dF/dt slowed down with increasing length of the muscle and was virtually identical in diseased tissue. This study shows for the first time that muscle length regulates cross-bridge kinetics in human myocardium under near-physiological conditions and that those kinetics are preserved in the right ventricular tissues of heart failure patients. Copyright © 2015 the American Physiological Society.

  10. Creating a market: an economic analysis of the purchaser-provider model.

    PubMed

    Shackley, P; Healey, A

    1993-09-01

    The focus of this paper is the extent to which the purchaser-provider split and the creation of a market in the provision of health care can be expected to bring about greater efficiency within the new NHS. The starting point is a theoretical discussion of markets and competition. In particular, emphasis is placed upon the economic model of perfect competition. It is argued that because of the existence of externalities, uncertainty and a lack of perfect information, an unregulated market in health care will almost certainly fail. In view of this, the imperfect provider markets of monopoly and contestable markets, which are of particular relevance to health care, are discussed. A description of the new health care market and the principal actors within it is followed by an evaluation of the new health care market. It is argued that in view of the restrictions to competition that exist between providers, some form of price regulation will be necessary to prevent monopolistic behaviour in the hospital sector. Regulation of purchasers is also suggested as a means of improving efficiency. It is concluded that competition may be a necessary condition for increased efficiency in health care provision, but is not sufficient in itself. Other incentives in the hospital sector are necessary to assist the market process and to enhance its impact on efficiency.

  11. Diversity and leadership.

    PubMed

    Chin, Jean Lau; Sanchez-Hucles, Janis

    2007-09-01

    Comments on the six articles contained in the special issue of the American Psychologist (January 2007) devoted to leadership, written by W. Bennis; S. J. Zaccaro; V. H. Vroom and A. G. Yago; B. J. Avolio; R. J. Sternberg; and R. J. Hackman and R. Wageman. The current authors express concern that the special issue failed to include attention to issues of diversity and intersecting identities as they pertain to leadership. A Special Issue Part II on Diversity and Leadership is being proposed to (a) advance new models of leadership, (b) expand on existing leadership theories, and (c) incorporate diversity and multiple identities in the formulation of more inclusive leadership research and theory. The goal of this special issue will be to revise our theories of leadership and our understanding of effective leadership to include gender, racial/ethnic minority status, sexual orientation, and disability status.

  12. Evaluating Simulated Tropical Convective Cores using HAIC-HIWC Microphysics and Dynamics Observations

    NASA Astrophysics Data System (ADS)

    Stanford, M.; Varble, A.; Zipser, E. J.; Strapp, J. W.; Leroy, D.; Schwarzenboeck, A.; Korolev, A.; Potts, R.

    2016-12-01

    A model intercomparison study is conducted to identify biases in simulated tropical convective core microphysical properties using two popular bulk parameterization schemes (Thompson and Morrison) and the Fast Spectral Bin Microphysics (FSBM) scheme. In-situ aircraft measurements of total condensed water content (TWC) and particle size distributions are compared with output from high-resolution WRF simulations of 4 mesoscale convective system (MCS) cases during the High Altitude Ice Crystals-High Ice Water Content (HAIC-HIWC) field campaign conducted in Darwin, Australia in 2014 and Cayenne, French Guiana in 2015. Observations of TWC collected using an isokinetic evaporator probe (IKP) optimized for high IWC measurements in conjunction with particle image processing from two optical array probes aboard the Falcon-20 research aircraft were used to constrain mass-size relationships in the observational dataset. Hydrometeor mass size distributions are compared between retrievals and simulations providing insight into the well-known high bias in simulated convective radar reflectivity. For TWC > 1 g m-3 between -10 and -40°C, simulations generally produce significantly greater median mass diameters (MMDs). Observations indicate that a sharp particle size mode occurs at 300 μm for large TWC values (> 2 g m-3) regardless of temperature. All microphysics schemes fail to reproduce this feature, and relative contributions of different hydrometeor species to this size bias vary between schemes. Despite far greater sample sizes, simulations also fail to produce high TWC conditions with very little of the mass contributed by large particles for a range of temperatures, despite such conditions being observed. Considering vapor grown particles alone in comparison with observations fails to correct the bias present in all schemes. Decreasing horizontal resolution from 1 km to 333 m shifts graupel and rain size distributions to slightly smaller sizes, but increased resolution alone will clearly not eliminate model biases. Results instead indicate that biases in both hydrometeor size distribution assumptions and parameterized processes also exist and need to be addressed before cloud and precipitation properties of convective systems can be adequately predicted.

  13. Evaluation of Multi-Level Support Structure Requirements for New Weapon Systems.

    DTIC Science & Technology

    1987-09-01

    transformer 1 total consumed manhours on this level 19.45 hrs average manhrs within 4 weeks on this level : .38 hrs average rounded number of mainten; personal ...major unit data to provide conclusions about the logistics behavior of failing weapon systems. The modeling of system behavior with CAESAR has severa-l...characteristic data and major unit data to provide conclusions about the logistics behavior of failing weapon systems. The modelling of system behavior

  14. Configurable product design considering the transition of multi-hierarchical models

    NASA Astrophysics Data System (ADS)

    Ren, Bin; Qiu, Lemiao; Zhang, Shuyou; Tan, Jianrong; Cheng, Jin

    2013-03-01

    The current research of configurable product design mainly focuses on how to convert a predefined set of components into a valid set of product structures. With the scale and complexity of configurable products increasing, the interdependencies between customer demands and product structures grow up as well. The result is that existing product structures fails to satisfy the individual customer requirements and hence product variants are needed. This paper is aimed to build a bridge between customer demands and product structures in order to make demand-driven fast response design feasible. First of all, multi-hierarchical models of configurable product design are established with customer demand model, technical requirement model and product structure model. Then, the transition of multi-hierarchical models among customer demand model, technical requirement model and product structure model is solved with fuzzy analytic hierarchy process (FAHP) and the algorithm of multi-level matching. Finally, optimal structure according to the customer demands is obtained with the calculation of Euclidean distance and similarity of some cases. In practice, the configuration design of a clamping unit of injection molding machine successfully performs an optimal search strategy for the product variants with reasonable satisfaction to individual customer demands. The proposed method can automatically generate a configuration design with better alternatives for each product structures, and shorten the time of finding the configuration of a product.

  15. A single factor underlies the metabolic syndrome: a confirmatory factor analysis.

    PubMed

    Pladevall, Manel; Singal, Bonita; Williams, L Keoki; Brotons, Carlos; Guyer, Heidi; Sadurni, Josep; Falces, Carles; Serrano-Rios, Manuel; Gabriel, Rafael; Shaw, Jonathan E; Zimmet, Paul Z; Haffner, Steven

    2006-01-01

    Confirmatory factor analysis (CFA) was used to test the hypothesis that the components of the metabolic syndrome are manifestations of a single common factor. Three different datasets were used to test and validate the model. The Spanish and Mauritian studies included 207 men and 203 women and 1,411 men and 1,650 women, respectively. A third analytical dataset including 847 men was obtained from a previously published CFA of a U.S. population. The one-factor model included the metabolic syndrome core components (central obesity, insulin resistance, blood pressure, and lipid measurements). We also tested an expanded one-factor model that included uric acid and leptin levels. Finally, we used CFA to compare the goodness of fit of one-factor models with the fit of two previously published four-factor models. The simplest one-factor model showed the best goodness-of-fit indexes (comparative fit index 1, root mean-square error of approximation 0.00). Comparisons of one-factor with four-factor models in the three datasets favored the one-factor model structure. The selection of variables to represent the different metabolic syndrome components and model specification explained why previous exploratory and confirmatory factor analysis, respectively, failed to identify a single factor for the metabolic syndrome. These analyses support the current clinical definition of the metabolic syndrome, as well as the existence of a single factor that links all of the core components.

  16. 75 FR 26883 - Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model ERJ 170 and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-13

    ... slat actuator structural failure (rupture) and its adjacent actuator torque limiter failing high... outboard slat actuator structural failure (rupture) and its adjacent actuator torque limiter failing high... requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in...

  17. Solutions for Failing High Schools: Converging Visions and Promising Models.

    ERIC Educational Resources Information Center

    Legters, Nettie; Balfanz, Robert; McPartland, James

    Promising solutions to the failings of traditional comprehensive high schools were reviewed to identify basic principles and strategies for improving high schools nationwide. Selected research studies, policy documents, and promising high school programs were reviewed. The review revealed the following principles for helping high schools better…

  18. Productive Failure in STEM Education

    ERIC Educational Resources Information Center

    Trueman, Rebecca J.

    2014-01-01

    Science education is criticized because it often fails to support problem-solving skills in students. Instead, the instructional methods primarily emphasize didactic models that fail to engage students and reveal how the material can be applied to solve real problems. To overcome these limitations, this study asked participants in a general…

  19. Failure Analysis of Fractured Poppet from Space Shuttle Orbiter Flow Control Valve

    NASA Technical Reports Server (NTRS)

    Russell, Richard

    2010-01-01

    This slide presentation reviews the failure analysis of a fractured poppet from a flow control valve (FCV) used on the space shuttle. This presentation has focused on the laboratory analysis of the failed hardware. The use of Scanning electron fractography during the investigation led to the conclusion that the poppet failed due to fatigue cracking that, most likely, occurred under changing loading conditions. The initial investigation led to a more thorough test of poppets that had been retired, this testing led to the conclusion that the thumbnail cracks in the flight hardware had existed for the life of the shuttle program. This led to a program to develop an eddy current technique that was capable of detecting small very tight cracks.

  20. Confirmatory Factor Analysis of the Trinity Inventory of Precursors to Suicide (TIPS) and Its Relationship to Hopelessness and Depression

    ERIC Educational Resources Information Center

    Smyth, Caroline L.; MacLachlan, Malcolm

    2005-01-01

    Numerous existing measures assess attitudes toward suicide yet fail to account for contextual factors. The Trinity Inventory of Precursors to Suicide (TIPS) is presented as an alternative, with implications for the development of prevention programs. Having previously reported exploratory analysis of the TIPS; confirmatory factor analysis and…

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