Mathematical modeling of enzyme production using Trichoderma harzianum P49P11 and sugarcane bagasse as carbon source.

PubMed

Gelain, Lucas; da Cruz Pradella, José Geraldo; da Costa, Aline Carvalho

2015-12-01

A mathematical model to describe the kinetics of enzyme production by the filamentous fungus Trichoderma harzianum P49P11 was developed using a low cost substrate as main carbon source (pretreated sugarcane bagasse). The model describes the cell growth, variation of substrate concentration and production of three kinds of enzymes (cellulases, beta-glucosidase and xylanase) in different sugarcane bagasse concentrations (5; 10; 20; 30; 40 gL(-1)). The 10 gL(-1) concentration was used to validate the model and the other to parameter estimation. The model for enzyme production has terms implicitly representing induction and repression. Substrate variation was represented by a simple degradation rate. The models seem to represent well the kinetics with a good fit for the majority of the assays. Validation results indicate that the models are adequate to represent the kinetics for a biotechnological process. Copyright © 2015 Elsevier Ltd. All rights reserved.

7 CFR 225.7 - Program monitoring and assistance.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., food service management company representatives, auditors, and health inspectors who will participate... adequately for the Program. (c) Food specifications and meal quality standards. With the assistance of the... and model meal quality standards which shall become part of all contracts between vended sponsors and...

Ecosystem-scale VOC fluxes during an extreme drought in a broad-leaf temperate forest of the Missouri Ozarks (central USA)

EPA Science Inventory

Considerable amounts and varieties of biogenic volatile organic compounds (BVOCs) are exchanged between vegetation and the surrounding air. These BVOCs play key ecological and atmospheric roles that must be adequately represented for accurately modeling the coupled biosphere-atmo...

Monitoring, modelling and environmental exposure assessment of industrial chemicals in the aquatic environment.

PubMed

Holt, M S; Fox, K; Griessbach, E; Johnsen, S; Kinnunen, J; Lecloux, A; Murray-Smith, R; Peterson, D R; Schröder, R; Silvani, M; ten Berge, W F; Toy, R J; Feijtel, T C

2000-12-01

Monitoring and laboratory data play integral roles alongside fate and exposure models in comprehensive risk assessments. The principle in the European Union Technical Guidance Documents for risk assessment is that measured data may take precedence over model results but only after they are judged to be of adequate reliability and to be representative of the particular environmental compartments to which they are applied. In practice, laboratory and field data are used to provide parameters for the models, while monitoring data are used to validate the models' predictions. Thus, comprehensive risk assessments require the integration of laboratory and monitoring data with the model predictions. However, this interplay is often overlooked. Discrepancies between the results of models and monitoring should be investigated in terms of the representativeness of both. Certainly, in the context of the EU risk assessment of existing chemicals, the specific requirements for monitoring data have not been adequately addressed. The resources required for environmental monitoring, both in terms of manpower and equipment, can be very significant. The design of monitoring programmes to optimise the use of resources and the use of models as a cost-effective alternative are increasing in importance. Generic considerations and criteria for the design of new monitoring programmes to generate representative quality data for the aquatic compartment are outlined and the criteria for the use of existing data are discussed. In particular, there is a need to improve the accessibility to data sets, to standardise the data sets, to promote communication and harmonisation of programmes and to incorporate the flexibility to change monitoring protocols to amend the chemicals under investigation in line with changing needs and priorities.

On storm movement and its applications

NASA Astrophysics Data System (ADS)

Niemczynowicz, Janusz

Rainfall-runoff models applicable for design and analysis of sewage systems in urban areas are further developed in order to represent better different physical processes going on on an urban catchment. However, one important part of the modelling procedure, the generation of the rainfall input is still a weak point. The main problem is lack of adequate rainfall data which represent temporal and spatial variations of the natural rainfall process. Storm movement is a natural phenomenon which influences urban runoff. However, the rainfall movement and its influence on runoff generation process is not represented in presently available urban runoff simulation models. Physical description of the rainfall movement and its parameters is given based on detailed measurements performed on twelve gauges in Lund, Sweden. The paper discusses the significance of the rainfall movement on the runoff generation process and gives suggestions how the rainfall movement parameters may be used in runoff modelling.

A Proposed Model for Assessing Defendant Competence to Self-Represent.

PubMed

White, Mitzi M S; Gutheil, Thomas G

2016-12-01

The increasing number of criminal defendants who are choosing to self-represent poses special challenges for legal systems with regard to the types of limits that should be placed on a defendant's basic human right to defend himself without the assistance of counsel. While courts strive to respect the dignity and autonomy of the defendant that are encompassed in this right, they also want to ensure that justice is delivered and the dignity of the courtroom is maintained. The Supreme Court of the United States, in its opinion in Indiana v. Edwards (2008), held that while the right to self-represent recognized in Faretta v. California (1975) remains, states and trial judges can place limits on a defendant's right to self-representation when a defendant lacks the mental capacities needed to prepare and conduct an adequate defense. Following the court's lead, we first examine the types and range of tasks that a defendant who chooses to self-represent must perform. Based on this analysis, we propose a five-part model that forensic practitioners can use as a conceptual framework for assessing whether a defendant has deficits that would affect his competence to perform critical self-representation tasks. The five areas that the model recommends practitioners assess are whether a defendant can engage in goal-directed behaviors, has sufficient communication skills, can engage in constructive social intercourse, can control his emotions in an adversarial arena, and has the cognitive abilities needed to argue his case adequately. It is recommended that practitioners use the model in their testimony to provide the trier of fact with a comprehensive report of the areas in which a defendant has deficits that will prevent him from protecting his interests in receiving a fair and equitable trial. © 2016 American Academy of Psychiatry and the Law.

Electron beam generation in the turbulent plasma of Z-pinch discharges

NASA Astrophysics Data System (ADS)

Vikhrev, Victor V.; Baronova, Elena O.

1997-05-01

Numerical modeling of the process of electron beam generation in z-pinch discharges are presented. The proposed model represents the electron beam generation under turbulent plasma conditions. Strong current distribution inhomogeneity in the plasma column has been accounted for the adequate generation process investigation. Electron beam is generated near the maximum of compression due to run away mechanism and it is not related with the current break effect.

Cognitive Attributes of Adequate and Inadequate Responders to Reading Intervention in Middle School

PubMed Central

Miciak, Jeremy; Stuebing, Karla K.; Vaughn, Sharon; Roberts, Greg; Barth, Amy Elizabeth; Fletcher, Jack M.

2016-01-01

No studies have investigated the cognitive attributes of middle school students who are adequate and inadequate responders to Tier 2 reading intervention. We compared students in Grades 6 and 7 representing groups of adequate responders (n = 77) and inadequate responders who fell below criteria in (a) comprehension (n = 54); (b) fluency (n = 45); and (c) decoding, fluency, and comprehension (DFC; n = 45). These students received measures of phonological awareness, listening comprehension, rapid naming, processing speed, verbal knowledge, and nonverbal reasoning. Multivariate comparisons showed a significant Group-by-Task interaction: the comprehension-impaired group demonstrated primary difficulties with verbal knowledge and listening comprehension, the DFC group with phonological awareness, and the fluency-impaired group with phonological awareness and rapid naming. A series of regression models investigating whether responder status explained unique variation in cognitive skills yielded largely null results consistent with a continuum of severity associated with level of reading impairment, with no evidence for qualitative differences in the cognitive attributes of adequate and inadequate responders. PMID:28579668

Cognitive Attributes of Adequate and Inadequate Responders to Reading Intervention in Middle School.

PubMed

Miciak, Jeremy; Stuebing, Karla K; Vaughn, Sharon; Roberts, Greg; Barth, Amy Elizabeth; Fletcher, Jack M

2014-12-01

No studies have investigated the cognitive attributes of middle school students who are adequate and inadequate responders to Tier 2 reading intervention. We compared students in Grades 6 and 7 representing groups of adequate responders ( n = 77) and inadequate responders who fell below criteria in (a) comprehension ( n = 54); (b) fluency ( n = 45); and (c) decoding, fluency, and comprehension (DFC; n = 45). These students received measures of phonological awareness, listening comprehension, rapid naming, processing speed, verbal knowledge, and nonverbal reasoning. Multivariate comparisons showed a significant Group-by-Task interaction: the comprehension-impaired group demonstrated primary difficulties with verbal knowledge and listening comprehension, the DFC group with phonological awareness, and the fluency-impaired group with phonological awareness and rapid naming. A series of regression models investigating whether responder status explained unique variation in cognitive skills yielded largely null results consistent with a continuum of severity associated with level of reading impairment, with no evidence for qualitative differences in the cognitive attributes of adequate and inadequate responders.

The strengths and weaknesses of inverted pendulum models of human walking.

PubMed

McGrath, Michael; Howard, David; Baker, Richard

2015-02-01

An investigation into the kinematic and kinetic predictions of two "inverted pendulum" (IP) models of gait was undertaken. The first model consisted of a single leg, with anthropometrically correct mass and moment of inertia, and a point mass at the hip representing the rest of the body. A second model incorporating the physiological extension of a head-arms-trunk (HAT) segment, held upright by an actuated hip moment, was developed for comparison. Simulations were performed, using both models, and quantitatively compared with empirical gait data. There was little difference between the two models' predictions of kinematics and ground reaction force (GRF). The models agreed well with empirical data through mid-stance (20-40% of the gait cycle) suggesting that IP models adequately simulate this phase (mean error less than one standard deviation). IP models are not cyclic, however, and cannot adequately simulate double support and step-to-step transition. This is because the forces under both legs augment each other during double support to increase the vertical GRF. The incorporation of an actuated hip joint was the most novel change and added a new dimension to the classic IP model. The hip moment curve produced was similar to those measured during experimental walking trials. As a result, it was interpreted that the primary role of the hip musculature in stance is to keep the HAT upright. Careful consideration of the differences between the models throws light on what the different terms within the GRF equation truly represent. Copyright © 2014 Elsevier B.V. All rights reserved.

Numerical modelling and experimental study of liquid evaporation during gel formation

NASA Astrophysics Data System (ADS)

Pokusaev, B. G.; Khramtsov, D. P.

2017-11-01

Gels are promising materials in biotechnology and medicine as a medium for storing cells for bioprinting applications. Gel is a two-phase system consisting of solid medium and liquid phase. Understanding of a gel structure evolution and gel aging during liquid evaporation is a crucial step in developing new additive bioprinting technologies. A numerical and experimental study of liquid evaporation was performed. In experimental study an evaporation process of an agarose gel layer located on Petri dish was observed and mass difference was detected using electronic scales. Numerical model was based on a smoothed particle hydrodynamics method. Gel in a model was represented as a solid-liquid system and liquid evaporation was modelled due to capillary forces and heat transfer. Comparison of experimental data and numerical results demonstrated that model can adequately represent evaporation process in agarose gel.

Parameter dimensionality reduction of a conceptual model for streamflow prediction in Canadian, snowmelt dominated ungauged basins

NASA Astrophysics Data System (ADS)

Arsenault, Richard; Poissant, Dominique; Brissette, François

2015-11-01

This paper evaluated the effects of parametric reduction of a hydrological model on five regionalization methods and 267 catchments in the province of Quebec, Canada. The Sobol' variance-based sensitivity analysis was used to rank the model parameters by their influence on the model results and sequential parameter fixing was performed. The reduction in parameter correlations improved parameter identifiability, however this improvement was found to be minimal and was not transposed in the regionalization mode. It was shown that 11 of the HSAMI models' 23 parameters could be fixed with little or no loss in regionalization skill. The main conclusions were that (1) the conceptual lumped models used in this study did not represent physical processes sufficiently well to warrant parameter reduction for physics-based regionalization methods for the Canadian basins examined and (2) catchment descriptors did not adequately represent the relevant hydrological processes, namely snow accumulation and melt.

The Dependability of the General Factor of Intelligence: Why Small, Single-Factor Models Do Not Adequately Represent "g"

ERIC Educational Resources Information Center

Major, Jason T.; Johnson, Wendy; Bouchard, Thomas J., Jr.

2011-01-01

Floyd, Shands, Rafael, Bergeron and McGrew (2009) used generalizability theory to test the reliability of general-factor loadings and to compare three different sources of error in them: the test battery size, the test battery composition, the factor-extraction technique, and their interactions. They found that their general-factor loadings were…

Hydropower Modeling Challenges

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

Stoll, Brady; Andrade, Juan; Cohen, Stuart

Hydropower facilities are important assets for the electric power sector and represent a key source of flexibility for electric grids with large amounts of variable generation. As variable renewable generation sources expand, understanding the capabilities and limitations of the flexibility from hydropower resources is important for grid planning. Appropriately modeling these resources, however, is difficult because of the wide variety of constraints these plants face that other generators do not. These constraints can be broadly categorized as environmental, operational, and regulatory. This report highlights several key issues involving incorporating these constraints when modeling hydropower operations in terms of production costmore » and capacity expansion. Many of these challenges involve a lack of data to adequately represent the constraints or issues of model complexity and run time. We present several potential methods for improving the accuracy of hydropower representation in these models to allow for a better understanding of hydropower's capabilities.« less

Response Surface Modeling Tolerance and Inference Error Risk Specifications: Proposed Industry Standards

NASA Technical Reports Server (NTRS)

DeLoach, Richard

2012-01-01

This paper reviews the derivation of an equation for scaling response surface modeling experiments. The equation represents the smallest number of data points required to fit a linear regression polynomial so as to achieve certain specified model adequacy criteria. Specific criteria are proposed which simplify an otherwise rather complex equation, generating a practical rule of thumb for the minimum volume of data required to adequately fit a polynomial with a specified number of terms in the model. This equation and the simplified rule of thumb it produces can be applied to minimize the cost of wind tunnel testing.

Design of cryogenic tanks for launch vehicles

NASA Technical Reports Server (NTRS)

Copper, Charles; Pilkey, Walter D.; Haviland, John K.

1990-01-01

During the period since January 1990, work was concentrated on the problem of the buckling of the structure of an ALS (advanced launch systems) tank during the boost phase. The primary problem was to analyze a proposed hat stringer made by superplastic forming, and to compare it with an integrally stiffened stringer design. A secondary objective was to determine whether structural rings having the identical section to the stringers will provide adequate support against overall buckling. All of the analytical work was carried out with the TESTBED program on the CONVEX computer, using PATRAN programs to create models. Analyses of skin/stringer combinations have shown that the proposed stringer design is an adequate substitute for the integrally stiffened stringer. Using a highly refined mesh to represent the corrugations in the vertical webs of the hat stringers, effective values were obtained for cross-sectional area, moment of inertia, centroid height, and torsional constant. Not only can these values be used for comparison with experimental values, but they can also be used for beams to replace the stringers and frames in analytical models of complete sections of tank. The same highly refined model was used to represent a section of skin reinforced by a stringer and a ring segment in the configuration of a cross. It was intended that this would provide a baseline buckling analysis representing a basic mode, however, the analysis proved to be beyond the scope of the CONVEX computer. One quarter of this model was analyzed, however, to provide information on buckling between the spot welds. Models of large sections of the tank structure were made, using beam elements to model the stringers and frames. In order to represent the stiffening effects of pressure, stresses and deflections under pressure should first be obtained, and then the buckling analysis should be made on the structure so deflected. So far, uncharacteristic deflections under pressure were obtained from the TESTBED program using two types of structural elements. Similar results were obtained using the ANSYS program on a mainframe computer, although two finite element programs on microcomputers have yielded realistic results.

"Something Adequate"? In Memoriam Seamus Heaney, Sister Quinlan, Nirbhaya

ERIC Educational Resources Information Center

Parker, Jan

2014-01-01

Seamus Heaney talked of poetry's responsibility to represent the "bloody miracle", the "terrible beauty" of atrocity; to create "something adequate". This article asks, what is adequate to the burning and eating of a nun and the murderous gang rape and evisceration of a medical student? It considers Njabulo Ndebele's…

AUTOMATIC ENGLISH-TO-LOGIC TRANSLATION IN A SIMPLIFIED MODEL, A STUDY IN THE LOGIC OF GRAMMAR. FINAL REPORT.

ERIC Educational Resources Information Center

BACKER, P.O.; BOHNERT, H.G.

THE LATEST IN A SERIES OF ENGLISH-LIKE LANGUAGES IS DESCRIBED WHICH IS TRANSLATABLE INTO FORMS OF A FIRST-ORDER PREDICATE CALCULUS NOTATION. THE STUDY IS BASED ON THE HYPOTHESIS THAT SYNTACTIC AMBIGUITY ARISING FROM DIFFERENCES IN DEEP STRUCTURE CAN BE ADEQUATELY DESCRIBED ONLY IF THE DEEP STRUCTURES CAN BE SYSTEMATICALLY REPRESENTED. THE NOTATION…

Measurement and modeling of unsaturated hydraulic conductivity

USGS Publications Warehouse

Perkins, Kim S.; Elango, Lakshmanan

2011-01-01

The unsaturated zone plays an extremely important hydrologic role that influences water quality and quantity, ecosystem function and health, the connection between atmospheric and terrestrial processes, nutrient cycling, soil development, and natural hazards such as flooding and landslides. Unsaturated hydraulic conductivity is one of the main properties considered to govern flow; however it is very difficult to measure accurately. Knowledge of the highly nonlinear relationship between unsaturated hydraulic conductivity (K) and volumetric water content is required for widely-used models of water flow and solute transport processes in the unsaturated zone. Measurement of unsaturated hydraulic conductivity of sediments is costly and time consuming, therefore use of models that estimate this property from more easily measured bulk-physical properties is common. In hydrologic studies, calculations based on property-transfer models informed by hydraulic property databases are often used in lieu of measured data from the site of interest. Reliance on database-informed predicted values with the use of neural networks has become increasingly common. Hydraulic properties predicted using databases may be adequate in some applications, but not others. This chapter will discuss, by way of examples, various techniques used to measure and model hydraulic conductivity as a function of water content, K. The parameters that describe the K curve obtained by different methods are used directly in Richards’ equation-based numerical models, which have some degree of sensitivity to those parameters. This chapter will explore the complications of using laboratory measured or estimated properties for field scale investigations to shed light on how adequately the processes are represented. Additionally, some more recent concepts for representing unsaturated-zone flow processes will be discussed.

Preliminary study: Moisture-polymer interaction. Stuby objectives

NASA Technical Reports Server (NTRS)

Wen, L. C.

1985-01-01

The problems associated with mathematically modeling water-module interaction phenomena, including sorption and desorption, diffusion, and permeation are discussed. With reliable analytical models, an extensive materials data base, and solar radiation surface meteorological observations (SOLMET) weather data, predicting module lifetimes in realistic environments can become a practical reality. The status of the present techniques of simulating the various transport mechanisms was reported. The Dent model (a modified Brunauer-Emmet-Teller) approach represented polyvinyl butyral (PVB) sorption data. A 100-layer material model and Fick's diffusion model gave diffusivity values exhibiting adequate agreement with those measured for PVB. Diffusivity of PVB is concentration dependent, decreasing as the water content in PVB increases. The temperature dependence of diffusion in PVB is well modeled by the Arrhenius rate equation. Equilibrium conductivity and leakage current data are well represented by Hearle's model for bulk ionic conductivity. A nodal network analysis using the Systems Improved Numerical Differencing Analyzer (SINDA) Thermal Analyzer gave reasonable correlation with measurable data. It is concluded that realistic lifetime predictions seem to be feasible.

Measured values of coal mine stopping resistance

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

Oswald, N.; Prosser, B.; Ruckman, R.

2008-12-15

As coal mines become larger, the number of stoppings in the ventilation system increases. Each stopping represents a potential leakage path which must be adequately represented in the ventilation model. Stopping resistance can be calculated using two methods, the USBM method, used to determine a resistance for a single stopping, and the MVS technique, in which an average resistance is calculated for multiple stoppings. Through MVS data collected from ventilation surveys of different subsurface coal mines, average resistances for stoppings were determined for stopping in poor, average, good, and excellent conditions. The calculated average stoppings resistance were determined for concretemore » block and Kennedy stopping. Using the average stopping resistance, measured and calculated using the MVS method, provides a ventilation modeling tool which can be used to construct more accurate and useful ventilation models. 3 refs., 3 figs.« less

Stochastic nature of Landsat MSS data

NASA Technical Reports Server (NTRS)

Labovitz, M. L.; Masuoka, E. J.

1987-01-01

A multiple series generalization of the ARIMA models is used to model Landsat MSS scan lines as sequences of vectors, each vector having four elements (bands). The purpose of this work is to investigate if Landsat scan lines can be described by a general multiple series linear stochastic model and if the coefficients of such a model vary as a function of satellite system and target attributes. To accomplish this objective, an exploratory experimental design was set up incorporating six factors, four representing target attributes - location, cloud cover, row (within location), and column (within location) - and two factors representing system attributes - satellite number and detector bank. Each factor was included in the design at two levels and, with two replicates per treatment, 128 scan lines were analyzed. The results of the analysis suggests that a multiple AR(4) model is an adequate representation across all scan lines. Furthermore, the coefficients of the AR(4) model vary with location, particularly changes in physiography (slope regimes), and with percent cloud cover, but are insensitive to changes in system attributes.

Lower-extremity musculoskeletal geometry affects the calculation of patellofemoral forces in vertical jumping and weightlifting.

PubMed

Cleather, D I; Bull, A M J

2010-01-01

The calculation of the patellofemoral joint contact force using three-dimensional (3D) modelling techniques requires a description of the musculoskeletal geometry of the lower limb. In this study, the influence of the complexity of the muscle model was studied by considering two different muscle models, the Delp and Horsman models. Both models were used to calculate the patellofemoral force during standing, vertical jumping, and Olympic-style weightlifting. The patellofemoral forces predicted by the Horsman model were markedly lower than those predicted by the Delp model in all activities and represented more realistic values when compared with previous work. This was found to be a result of a lower level of redundancy in the Delp model, which forced a higher level of muscular activation in order to allow a viable solution. The higher level of complexity in the Horsman model resulted in a greater degree of redundancy and consequently lower activation and patellofemoral forces. The results of this work demonstrate that a well-posed muscle model must have an adequate degree of complexity to create a sufficient independence, variability, and number of moment arms in order to ensure adequate redundancy of the force-sharing problem such that muscle forces are not overstated.

Cognitive Attributes of Adequate and Inadequate Responders to Reading Intervention in Middle School

ERIC Educational Resources Information Center

Miciak, Jeremy; Stuebing, Karla K.; Vaughn, Sharon; Roberts, Greg; Barth, Amy E.; Fletcher, Jack M.

2014-01-01

No studies have investigated the cognitive attributes of middle school students who are adequate and inadequate responders to Tier 2 reading intervention. We compared students in Grades 6 and 7 representing groups of adequate responders (n = 77) and inadequate responders who fell below criteria in (a) comprehension (n = 54); (b) fluency (n = 45);…

Modeling the dynamics of multipartite quantum systems created departing from two-level systems using general local and non-local interactions

NASA Astrophysics Data System (ADS)

Delgado, Francisco

2017-12-01

Quantum information is an emergent area merging physics, mathematics, computer science and engineering. To reach its technological goals, it is requiring adequate approaches to understand how to combine physical restrictions, computational approaches and technological requirements to get functional universal quantum information processing. This work presents the modeling and the analysis of certain general type of Hamiltonian representing several physical systems used in quantum information and establishing a dynamics reduction in a natural grammar for bipartite processing based on entangled states.

Normal probabilities for Vandenberg AFB wind components - monthly reference periods for all flight azimuths, 0- to 70-km altitudes

NASA Technical Reports Server (NTRS)

Falls, L. W.

1975-01-01

Vandenberg Air Force Base (AFB), California, wind component statistics are presented to be used for aerospace engineering applications that require component wind probabilities for various flight azimuths and selected altitudes. The normal (Gaussian) distribution is presented as a statistical model to represent component winds at Vandenberg AFB. Head tail, and crosswind components are tabulated for all flight azimuths for altitudes from 0 to 70 km by monthly reference periods. Wind components are given for 11 selected percentiles ranging from 0.135 percent to 99.865 percent for each month. The results of statistical goodness-of-fit tests are presented to verify the use of the Gaussian distribution as an adequate model to represent component winds at Vandenberg AFB.

Simulations using patient data to evaluate systematic errors that may occur in 4D treatment planning: a proof of concept study.

PubMed

St James, Sara; Seco, Joao; Mishra, Pankaj; Lewis, John H

2013-09-01

The purpose of this work is to present a framework to evaluate the accuracy of four-dimensional treatment planning in external beam radiation therapy using measured patient data and digital phantoms. To accomplish this, 4D digital phantoms of two model patients were created using measured patient lung tumor positions. These phantoms were used to simulate a four-dimensional computed tomography image set, which in turn was used to create a 4D Monte Carlo (4DMC) treatment plan. The 4DMC plan was evaluated by simulating the delivery of the treatment plan over approximately 5 min of tumor motion measured from the same patient on a different day. Unique phantoms accounting for the patient position (tumor position and thorax position) at 2 s intervals were used to represent the model patients on the day of treatment delivery and the delivered dose to the tumor was determined using Monte Carlo simulations. For Patient 1, the tumor was adequately covered with 95.2% of the tumor receiving the prescribed dose. For Patient 2, the tumor was not adequately covered and only 74.3% of the tumor received the prescribed dose. This study presents a framework to evaluate 4D treatment planning methods and demonstrates a potential limitation of 4D treatment planning methods. When systematic errors are present, including when the imaging study used for treatment planning does not represent all potential tumor locations during therapy, the treatment planning methods may not adequately predict the dose to the tumor. This is the first example of a simulation study based on patient tumor trajectories where systematic errors that occur due to an inaccurate estimate of tumor motion are evaluated.

SPIN or LURCH : a Comparative Assessment of Model Checking and Stochastic Search for Temporal Properties in Procedural Code

NASA Technical Reports Server (NTRS)

Powell, John D.; Owens, David; Menzies, Tim

2004-01-01

The difficulty of how to test large systems, such as the one on board a NASA robotic remote explorer (RRE) vehicle, is fundamentally a search issue: the global state space representing all possible has yet to be solved, even after many decades of work. Randomized algorithms have been known to outperform their deterministic counterparts for search problems representing a wide range of applications. In the case study presented here, the LURCH randomized algorithm proved to be adequate to the task of testing a NASA RRE vehicle. LURCH found all the errors found by an earlier analysis of a more complete method (SPIN). Our empirical results are that LURCH can scale to much larger models than standard model checkers like SMV and SPIN. Further, the LURCH analysis was simpler than the SPIN analysis. The simplicity and scalability of LURCH are two compelling reasons for experimenting further with this tool.

Response of the solar atmosphere to a simple flare burst: UV emission from the flare transition layer.

NASA Astrophysics Data System (ADS)

Shmeleva, O. P.

The flare transition layer exists as a relatively steady formation even during impulsive heating. It is maintained by a heat flow from the high-temperature plasma, where the major part of the electron beam energy is absorbed. The lifetime of this plasma is much greater than the impulsive heating time. Intensities of resonance UV lines are calculated using both the model of impulsive nonthermal heating by energetic electrons and the model of continuous thermal heating. The calculated line intensity is almost constant during a long time. The line Doppler shifts predicted by the former model match observations. This suggests that the model represents sufficiently well the actual dynamics of the flare plasma. The flare transition layer is a thin formation, its thickness being Δξ = 1021m-2. It is therefore described adequately within the p = const approximation though the picture of hydrodynamic response of the solar atmosphere to the impulsive heating by energy flows is rather complicated and nonsteady, of course. The intensities of the C IV λλ154.8, 155.1 nm and O VI λλ103.2, 103.8 nm lines are calculated within the scope of the model of continuous thermal heating, in which the conductive heating of the flare transition layer is balanced by radiative cooling. The line intensities are proportional to the pressure in the layer, which permits the pressure to be found from the observed line intensities. The analysis reveals that both heating models adequately represent the actual structure and dynamics of plasma in a flare. In the flare transition layer, the classical heat conduction always does work.

Numerical model for the uptake of groundwater contaminants by phreatophytes

USGS Publications Warehouse

Widdowson, M.A.; El-Sayed, A.; Landmeyer, J.E.

2008-01-01

Conventional solute transport models do not adequately account for the effects of phreatophytic plant systems on contaminant concentrations in shallow groundwater systems. A numerical model was developed and tested to simulate threedimensional reactive solute transport in a heterogeneous porous medium. Advective-dispersive transport is coupled to biodegradation, sorption, and plantbased attenuation processes including plant uptake and sorption by plant roots. The latter effects are a function of the physical-chemical properties of the individual solutes and plant species. Models for plant uptake were tested and evaluated using the experimental data collected at a field site comprised of hybrid poplar trees. A non-linear equilibrium isotherm model best represented site conditions.

Cognitive Network Modeling as a Basis for Characterizing Human Communication Dynamics and Belief Contagion in Technology Adoption

NASA Technical Reports Server (NTRS)

Hutto, Clayton; Briscoe, Erica; Trewhitt, Ethan

2012-01-01

Societal level macro models of social behavior do not sufficiently capture nuances needed to adequately represent the dynamics of person-to-person interactions. Likewise, individual agent level micro models have limited scalability - even minute parameter changes can drastically affect a model's response characteristics. This work presents an approach that uses agent-based modeling to represent detailed intra- and inter-personal interactions, as well as a system dynamics model to integrate societal-level influences via reciprocating functions. A Cognitive Network Model (CNM) is proposed as a method of quantitatively characterizing cognitive mechanisms at the intra-individual level. To capture the rich dynamics of interpersonal communication for the propagation of beliefs and attitudes, a Socio-Cognitive Network Model (SCNM) is presented. The SCNM uses socio-cognitive tie strength to regulate how agents influence--and are influenced by--one another's beliefs during social interactions. We then present experimental results which support the use of this network analytical approach, and we discuss its applicability towards characterizing and understanding human information processing.

Improving simulated long-term responses of vegetation to temperature and precipitation extremes using the ACME land model

NASA Astrophysics Data System (ADS)

Ricciuto, D. M.; Warren, J.; Guha, A.

2017-12-01

While carbon and energy fluxes in current Earth system models generally have reasonable instantaneous responses to extreme temperature and precipitation events, they often do not adequately represent the long-term impacts of these events. For example, simulated net primary productivity (NPP) may decrease during an extreme heat wave or drought, but may recover rapidly to pre-event levels following the conclusion of the extreme event. However, field measurements indicate that long-lasting damage to leaves and other plant components often occur, potentially affecting the carbon and energy balance for months after the extreme event. The duration and frequency of such extreme conditions is likely to shift in the future, and therefore it is critical for Earth system models to better represent these processes for more accurate predictions of future vegetation productivity and land-atmosphere feedbacks. Here we modify the structure of the Accelerated Climate Model for Energy (ACME) land surface model to represent long-term impacts and test the improved model against observations from experiments that applied extreme conditions in growth chambers. Additionally, we test the model against eddy covariance measurements that followed extreme conditions at selected locations in North America, and against satellite-measured vegetation indices following regional extreme events.

On the use of three hydrological models as hypotheses to investigate the behaviour of a small Mediterranean catchment

NASA Astrophysics Data System (ADS)

Ruiz Pérez, Guiomar; Latron, Jérôme; Llorens, Pilar; Gallart, Francesc; Francés, Félix

2017-04-01

Selecting an adequate hydrological model is the first step to carry out a rainfall-runoff modelling exercise. A hydrological model is a hypothesis of catchment functioning, encompassing a description of dominant hydrological processes and predicting how these processes interact to produce the catchment's response to external forcing. Current research lines emphasize the importance of multiple working hypotheses for hydrological modelling instead of only using a single model. In line with this philosophy, here different hypotheses were considered and analysed to simulate the nonlinear response of a small Mediterranean catchment and to progress in the analysis of its hydrological behaviour. In particular, three hydrological models were considered representing different potential hypotheses: two lumped models called LU3 and LU4, and one distributed model called TETIS. To determine how well each specific model performed and to assess whether a model was more adequate than another, we raised three complementary tests: one based on the analysis of residual errors series, another based on a sensitivity analysis and the last one based on using multiple evaluation criteria associated to the concept of Pareto frontier. This modelling approach, based on multiple working hypotheses, helped to improve our perceptual model of the catchment behaviour and, furthermore, could be used as a guidance to improve the performance of other environmental models.

Modeling functional neuroanatomy for an anatomy information system.

PubMed

Niggemann, Jörg M; Gebert, Andreas; Schulz, Stefan

2008-01-01

Existing neuroanatomical ontologies, databases and information systems, such as the Foundational Model of Anatomy (FMA), represent outgoing connections from brain structures, but cannot represent the "internal wiring" of structures and as such, cannot distinguish between different independent connections from the same structure. Thus, a fundamental aspect of Neuroanatomy, the functional pathways and functional systems of the brain such as the pupillary light reflex system, is not adequately represented. This article identifies underlying anatomical objects which are the source of independent connections (collections of neurons) and uses these as basic building blocks to construct a model of functional neuroanatomy and its functional pathways. The basic representational elements of the model are unnamed groups of neurons or groups of neuron segments. These groups, their relations to each other, and the relations to the objects of macroscopic anatomy are defined. The resulting model can be incorporated into the FMA. The capabilities of the presented model are compared to the FMA and the Brain Architecture Management System (BAMS). Internal wiring as well as functional pathways can correctly be represented and tracked. This model bridges the gap between representations of single neurons and their parts on the one hand and representations of spatial brain structures and areas on the other hand. It is capable of drawing correct inferences on pathways in a nervous system. The object and relation definitions are related to the Open Biomedical Ontology effort and its relation ontology, so that this model can be further developed into an ontology of neuronal functional systems.

COMPARISON OF ECOLOGICAL COMMUNITIES: THE PROBLEM OF SAMPLE REPRESENTATIVENESS

EPA Science Inventory

Obtaining an adequate, representative sample of ecological communities to make taxon richness (TR) or compositional comparisons among sites is a continuing challenge. Sample representativeness literally means the similarity in species composition and relative abundance between a ...

A data-driven emulation framework for representing water-food nexus in a changing cold region

NASA Astrophysics Data System (ADS)

Nazemi, A.; Zandmoghaddam, S.; Hatami, S.

2017-12-01

Water resource systems are under increasing pressure globally. Growing population along with competition between water demands and emerging effects of climate change have caused enormous vulnerabilities in water resource management across many regions. Diagnosing such vulnerabilities and provision of effective adaptation strategies requires the availability of simulation tools that can adequately represent the interactions between competing water demands for limiting water resources and inform decision makers about the critical vulnerability thresholds under a range of potential natural and anthropogenic conditions. Despite a significant progress in integrated modeling of water resource systems, regional models are often unable to fully represent the contemplating dynamics within the key elements of water resource systems locally. Here we propose a data-driven approach to emulate a complex regional water resource system model developed for Oldman River Basin in southern Alberta, Canada. The aim of the emulation is to provide a detailed understanding of the trade-offs and interaction at the Oldman Reservoir, which is the key to flood control and irrigated agriculture in this over-allocated semi-arid cold region. Different surrogate models are developed to represent the dynamic of irrigation demand and withdrawal as well as reservoir evaporation and release individually. The nan-falsified offline models are then integrated through the water balance equation at the reservoir location to provide a coupled model for representing the dynamic of reservoir operation and water allocation at the local scale. The performance of individual and integrated models are rigorously examined and sources of uncertainty are highlighted. To demonstrate the practical utility of such surrogate modeling approach, we use the integrated data-driven model for examining the trade-off in irrigation water supply, reservoir storage and release under a range of changing climate, upstream streamflow and local irrigation conditions.

Man’s best friend: what can pet dogs teach us about non-Hodgkin lymphoma?

PubMed Central

Richards, Kristy L.; Suter, Steven E.

2014-01-01

Summary Animal models are essential for understanding lymphoma biology and testing new treatments prior to human studies. Spontaneously arising lymphomas in pet dogs represent an underutilized resource that could be used to complement current mouse lymphoma models, which do not adequately represent all aspects of the human disease. Canine lymphoma resembles human lymphoma in many important ways, including characteristic translocations and molecular abnormalities and similar therapeutic responses to chemotherapy, radiation, and newer targeted therapies (e.g. ibrutinib). Given the large number of pet dogs and high incidence of lymphoma, particularly in susceptible breeds, dogs represent a largely untapped resource for advancing the understanding and treatment of human lymphoma. This review highlights similarities in molecular biology, diagnosis, treatment, and outcomes between human and canine lymphoma. It also describes resources that are currently available to study canine lymphoma, advantages to be gained by exploiting the genetic breed structure in dogs, and current and future challenges and opportunities to take full advantage of this resource for lymphoma studies. PMID:25510277

The occupational physician's point of view: the model of man-made vitreous fibers.

PubMed Central

Brochard, P; Pairon, J C; Bignon, J

1994-01-01

This article gives a detailed description of the procedure the occupational physician uses in interpreting the available scientific data to provide useful information for prevention of pulmonary diseases related to man-made mineral fibers, particularly lung cancer and mesothelioma. As it is difficult to reach definite conclusions from human data on the toxicity of specific fibers, an experimental approach is needed. Concerning animal data, we emphasize that adequate inhalation studies are the "gold standard" for extrapolating to humans. However, experiments using intracavitary injection or cells in vitro may represent indicative tests for a possible carcinogenic effect. Such tests should be used to assess the intrinsic carcinogenicity of fibers, but they must be confirmed by adequate inhalation models. Despite the present uncertainties, a proposal is made that could make it possible to classify fibers according to their toxicologic potential, grading them in accordance with physicochemical parameters, in vitro testing, and animal experiments. This procedure may be applicable to nonvitreous fibers and to organic fibers. PMID:7882952

Simple theoretical models for composite rotor blades

NASA Technical Reports Server (NTRS)

Valisetty, R. R.; Rehfield, L. W.

1984-01-01

The development of theoretical rotor blade structural models for designs based upon composite construction is discussed. Care was exercised to include a member of nonclassical effects that previous experience indicated would be potentially important to account for. A model, representative of the size of a main rotor blade, is analyzed in order to assess the importance of various influences. The findings of this model study suggest that for the slenderness and closed cell construction considered, the refinements are of little importance and a classical type theory is adequate. The potential of elastic tailoring is dramatically demonstrated, so the generality of arbitrary ply layup in the cell wall is needed to exploit this opportunity.

Role of natural analogs in performance assessment of nuclear waste repositories

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

Sagar, B.; Wittmeyer, G.W.

1995-09-01

Mathematical models of the flow of water and transport of radionuclides in porous media will be used to assess the ability of deep geologic repositories to safely contain nuclear waste. These models must, in some sense, be validated to ensure that they adequately describe the physical processes occurring within the repository and its geologic setting. Inasmuch as the spatial and temporal scales over which these models must be applied in performance assessment are very large, validation of these models against laboratory and small-scale field experiments may be considered inadequate. Natural analogs may provide validation data that are representative of physico-chemicalmore » processes that occur over spatial and temporal scales as large or larger than those relevant to repository design. The authors discuss the manner in which natural analog data may be used to increase confidence in performance assessment models and conclude that, while these data may be suitable for testing the basic laws governing flow and transport, there is insufficient control of boundary and initial conditions and forcing functions to permit quantitative validation of complex, spatially distributed flow and transport models. The authors also express their opinion that, for collecting adequate data from natural analogs, resources will have to be devoted to them that are much larger than are devoted to them at present.« less

Topic Model for Graph Mining.

PubMed

Xuan, Junyu; Lu, Jie; Zhang, Guangquan; Luo, Xiangfeng

2015-12-01

Graph mining has been a popular research area because of its numerous application scenarios. Many unstructured and structured data can be represented as graphs, such as, documents, chemical molecular structures, and images. However, an issue in relation to current research on graphs is that they cannot adequately discover the topics hidden in graph-structured data which can be beneficial for both the unsupervised learning and supervised learning of the graphs. Although topic models have proved to be very successful in discovering latent topics, the standard topic models cannot be directly applied to graph-structured data due to the "bag-of-word" assumption. In this paper, an innovative graph topic model (GTM) is proposed to address this issue, which uses Bernoulli distributions to model the edges between nodes in a graph. It can, therefore, make the edges in a graph contribute to latent topic discovery and further improve the accuracy of the supervised and unsupervised learning of graphs. The experimental results on two different types of graph datasets show that the proposed GTM outperforms the latent Dirichlet allocation on classification by using the unveiled topics of these two models to represent graphs.

Accelerating advances in continental domain hydrologic modeling

USGS Publications Warehouse

Archfield, Stacey A.; Clark, Martyn; Arheimer, Berit; Hay, Lauren E.; McMillan, Hilary; Kiang, Julie E.; Seibert, Jan; Hakala, Kirsti; Bock, Andrew R.; Wagener, Thorsten; Farmer, William H.; Andreassian, Vazken; Attinger, Sabine; Viglione, Alberto; Knight, Rodney; Markstrom, Steven; Over, Thomas M.

2015-01-01

In the past, hydrologic modeling of surface water resources has mainly focused on simulating the hydrologic cycle at local to regional catchment modeling domains. There now exists a level of maturity among the catchment, global water security, and land surface modeling communities such that these communities are converging toward continental domain hydrologic models. This commentary, written from a catchment hydrology community perspective, provides a review of progress in each community toward this achievement, identifies common challenges the communities face, and details immediate and specific areas in which these communities can mutually benefit one another from the convergence of their research perspectives. Those include: (1) creating new incentives and infrastructure to report and share model inputs, outputs, and parameters in data services and open access, machine-independent formats for model replication or reanalysis; (2) ensuring that hydrologic models have: sufficient complexity to represent the dominant physical processes and adequate representation of anthropogenic impacts on the terrestrial water cycle, a process-based approach to model parameter estimation, and appropriate parameterizations to represent large-scale fluxes and scaling behavior; (3) maintaining a balance between model complexity and data availability as well as uncertainties; and (4) quantifying and communicating significant advancements toward these modeling goals.

78 FR 55775 - Pipeline Safety: Information Collection Activities

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-11

...'' is open to wide interpretation and suggests that ``awareness'' be replaced with ``discovery'', which... conditions characterize ``discovery'' as ``when an operator's representative has adequate information from... ``adequate'' and ``probable'' in the definition of ``discovery'' provides additional clarity. Part A18 of the...

An agent-based hydroeconomic model to evaluate water policies in Jordan

NASA Astrophysics Data System (ADS)

Yoon, J.; Gorelick, S.

2014-12-01

Modern water systems can be characterized by a complex network of institutional and private actors that represent competing sectors and interests. Identifying solutions to enhance water security in such systems calls for analysis that can adequately account for this level of complexity and interaction. Our work focuses on the development of a hierarchical, multi-agent, hydroeconomic model that attempts to realistically represent complex interactions between hydrologic and multi-faceted human systems. The model is applied to Jordan, one of the most water-poor countries in the world. In recent years, the water crisis in Jordan has escalated due to an ongoing drought and influx of refugees from regional conflicts. We adopt a modular approach in which biophysical modules simulate natural and engineering phenomena, and human modules represent behavior at multiple scales of decision making. The human modules employ agent-based modeling, in which agents act as autonomous decision makers at the transboundary, state, organizational, and user levels. A systematic nomenclature and conceptual framework is used to characterize model agents and modules. Concepts from the Unified Modeling Language (UML) are adopted to promote clear conceptualization of model classes and process sequencing, establishing a foundation for full deployment of the integrated model in a scalable object-oriented programming environment. Although the framework is applied to the Jordanian water context, it is generalizable to other regional human-natural freshwater supply systems.

Fit Assessment of N95 Filtering-Facepiece Respirators in the U.S. Centers for Disease Control and Prevention Strategic National Stockpile.

PubMed

Bergman, Michael; Zhuang, Ziqing; Brochu, Elizabeth; Palmiero, Andrew

National Institute for Occupational Safety and Health (NIOSH)-approved N95 filtering-facepiece respirators (FFR) are currently stockpiled by the U.S. Centers for Disease Control and Prevention (CDC) for emergency deployment to healthcare facilities in the event of a widespread emergency such as an influenza pandemic. This study assessed the fit of N95 FFRs purchased for the CDC Strategic National Stockpile. The study addresses the question of whether the fit achieved by specific respirator sizes relates to facial size categories as defined by two NIOSH fit test panels. Fit test data were analyzed from 229 test subjects who performed a nine-donning fit test on seven N95 FFR models using a quantitative fit test protocol. An initial respirator model selection process was used to determine if the subject could achieve an adequate fit on a particular model; subjects then tested the adequately fitting model for the nine-donning fit test. Only data for models which provided an adequate initial fit (through the model selection process) for a subject were analyzed for this study. For the nine-donning fit test, six of the seven respirator models accommodated the fit of subjects (as indicated by geometric mean fit factor > 100) for not only the intended NIOSH bivariate and PCA panel sizes corresponding to the respirator size, but also for other panel sizes which were tested for each model. The model which showed poor performance may not be accurately represented because only two subjects passed the initial selection criteria to use this model. Findings are supportive of the current selection of facial dimensions for the new NIOSH panels. The various FFR models selected for the CDC Strategic National Stockpile provide a range of sizing options to fit a variety of facial sizes.

Fit Assessment of N95 Filtering-Facepiece Respirators in the U.S. Centers for Disease Control and Prevention Strategic National Stockpile

PubMed Central

Bergman, Michael; Zhuang, Ziqing; Brochu, Elizabeth; Palmiero, Andrew

2016-01-01

National Institute for Occupational Safety and Health (NIOSH)-approved N95 filtering-facepiece respirators (FFR) are currently stockpiled by the U.S. Centers for Disease Control and Prevention (CDC) for emergency deployment to healthcare facilities in the event of a widespread emergency such as an influenza pandemic. This study assessed the fit of N95 FFRs purchased for the CDC Strategic National Stockpile. The study addresses the question of whether the fit achieved by specific respirator sizes relates to facial size categories as defined by two NIOSH fit test panels. Fit test data were analyzed from 229 test subjects who performed a nine-donning fit test on seven N95 FFR models using a quantitative fit test protocol. An initial respirator model selection process was used to determine if the subject could achieve an adequate fit on a particular model; subjects then tested the adequately fitting model for the nine-donning fit test. Only data for models which provided an adequate initial fit (through the model selection process) for a subject were analyzed for this study. For the nine-donning fit test, six of the seven respirator models accommodated the fit of subjects (as indicated by geometric mean fit factor > 100) for not only the intended NIOSH bivariate and PCA panel sizes corresponding to the respirator size, but also for other panel sizes which were tested for each model. The model which showed poor performance may not be accurately represented because only two subjects passed the initial selection criteria to use this model. Findings are supportive of the current selection of facial dimensions for the new NIOSH panels. The various FFR models selected for the CDC Strategic National Stockpile provide a range of sizing options to fit a variety of facial sizes. PMID:26877587

Modeling Functional Neuroanatomy for an Anatomy Information System

PubMed Central

Niggemann, Jörg M.; Gebert, Andreas; Schulz, Stefan

2008-01-01

Objective Existing neuroanatomical ontologies, databases and information systems, such as the Foundational Model of Anatomy (FMA), represent outgoing connections from brain structures, but cannot represent the “internal wiring” of structures and as such, cannot distinguish between different independent connections from the same structure. Thus, a fundamental aspect of Neuroanatomy, the functional pathways and functional systems of the brain such as the pupillary light reflex system, is not adequately represented. This article identifies underlying anatomical objects which are the source of independent connections (collections of neurons) and uses these as basic building blocks to construct a model of functional neuroanatomy and its functional pathways. Design The basic representational elements of the model are unnamed groups of neurons or groups of neuron segments. These groups, their relations to each other, and the relations to the objects of macroscopic anatomy are defined. The resulting model can be incorporated into the FMA. Measurements The capabilities of the presented model are compared to the FMA and the Brain Architecture Management System (BAMS). Results Internal wiring as well as functional pathways can correctly be represented and tracked. Conclusion This model bridges the gap between representations of single neurons and their parts on the one hand and representations of spatial brain structures and areas on the other hand. It is capable of drawing correct inferences on pathways in a nervous system. The object and relation definitions are related to the Open Biomedical Ontology effort and its relation ontology, so that this model can be further developed into an ontology of neuronal functional systems. PMID:18579841

Transferability of optimally-selected climate models in the quantification of climate change impacts on hydrology

NASA Astrophysics Data System (ADS)

Chen, Jie; Brissette, François P.; Lucas-Picher, Philippe

2016-11-01

Given the ever increasing number of climate change simulations being carried out, it has become impractical to use all of them to cover the uncertainty of climate change impacts. Various methods have been proposed to optimally select subsets of a large ensemble of climate simulations for impact studies. However, the behaviour of optimally-selected subsets of climate simulations for climate change impacts is unknown, since the transfer process from climate projections to the impact study world is usually highly non-linear. Consequently, this study investigates the transferability of optimally-selected subsets of climate simulations in the case of hydrological impacts. Two different methods were used for the optimal selection of subsets of climate scenarios, and both were found to be capable of adequately representing the spread of selected climate model variables contained in the original large ensemble. However, in both cases, the optimal subsets had limited transferability to hydrological impacts. To capture a similar variability in the impact model world, many more simulations have to be used than those that are needed to simply cover variability from the climate model variables' perspective. Overall, both optimal subset selection methods were better than random selection when small subsets were selected from a large ensemble for impact studies. However, as the number of selected simulations increased, random selection often performed better than the two optimal methods. To ensure adequate uncertainty coverage, the results of this study imply that selecting as many climate change simulations as possible is the best avenue. Where this was not possible, the two optimal methods were found to perform adequately.

Contemporary Aspects of Marketing in Clinical Trials Including Segments of IT and Technology Transfer.

PubMed

Stamenovic, Milorad; Dobraca, Amra; Smajlovic, Mersiha

2018-01-01

The aim of this paper is to present the marketing strategy and the application of management (marketing management) and advertising in order to increase the efficiency of innovative approach in clinical trials that include and involve the use of new technologies and transfer of technologies. This paper has a descriptive character and represents a narrative review of the literature and new model implementation. Marketing models are primarily used to improve the inclusion of a larger (and appropriate) number of patients, but they can be credited for the stay and monitoring of patients in the trial. Regulatory mechanisms play an important role in the application of various marketing strategies within clinical trials. The value for the patient as the most important stakeholder is defined in the field of clinical trials according to Kotler's value model for the consumer. In order to achieve the best results it is important to adequately examine all the elements of clinical trials and apply this knowledge in creation of a marketing plan that will be made in accordance with the legal regulations defined globally and locally. In this paper, two challenges have been highlighted for the adequate application of marketing tools in the field of clinical trials, namely: defining business elements in order to provide an adequate marketing approach for clinical trials and technology transfer and ensuring uniformity and regulatory affirmation of marketing attitudes in clinical trials in all regions in which they are carried out in accordance with ICH-GCP and valid regulations.

Confirmatory factor analysis of the PTSD Checklist and the Clinician-Administered PTSD Scale in disaster workers exposed to the World Trade Center Ground Zero.

PubMed

Palmieri, Patrick A; Weathers, Frank W; Difede, JoAnn; King, Dainel W

2007-05-01

Although posttraumatic stress disorder (PTSD) factor analytic research has yielded little support for the DSM-IV 3-factor model of reexperiencing, avoidance, and hyperarousal symptoms, no clear consensus regarding alternative models has emerged. One possible explanation is differential instrumentation across studies. In the present study, the authors used confirmatory factor analysis to compare a self-report measure, the PTSD Checklist (PCL), and a structured clinical interview, the Clinician-Administered PTSD Scale (CAPS), in 2,960 utility workers exposed to the World Trade Center Ground Zero site. Although two 4-factor models fit adequately for each measure, the latent structure of the PCL was slightly better represented by correlated reexperiencing, avoidance, dysphoria, and hyperarousal factors, whereas that of the CAPS was slightly better represented by correlated reexperiencing, avoidance, emotional numbing, and hyperarousal factors. After accounting for method variance, the model specifying dysphoria as a distinct factor achieved slightly better fit. Patterns of correlations with external variables provided additional support for the dysphoria model. Implications regarding the underlying structure of PTSD are discussed.

ELECTROFISHING DISTANCE NEEDED TO ESTIMATE FISH SPECIES RICHNESS IN RAFTABLE WESTERN USA RIVERS

EPA Science Inventory

A critical issue in river monitoring is the minimum amount of sampling distance required to adequately represent the fish assemblage of a reach. Determining adequate sampling distance is important because it affects estimates of fish assemblage integrity and diversity at local a...

Density and white light brightness in looplike coronal mass ejections - Temporal evolution

NASA Technical Reports Server (NTRS)

Steinolfson, R. S.; Hundhausen, A. J.

1988-01-01

Three ambient coronal models suitable for studies of time-dependent phenomena were used to investigate the propagation of coronal mass ejections initiated in each atmosphere by an identical energy source. These models included those of a static corona with a dipole magnetic field, developed by Dryer et al. (1979); a steady polytropic corona with an equatorial coronal streamer, developed by Steinolfson et al. (1982); and Steinolfson's (1988) model of heated corona with an equatorial coronal streamer. The results indicated that the first model does not adequately represent the general characteristics of observed looplike mass ejections, and the second model simulated only some of the observed features. Only the third model, which included a heating term and a streamer, was found to yield accurate simulation of the mess ejection observations.

Development and test of an HTSMA supersonic inlet ramp actuator

NASA Astrophysics Data System (ADS)

Quackenbush, Todd R.; Carpenter, Bernie F.; Boschitsch, Alexander H.; Danilov, Pavel V.

2008-03-01

Use of Shape Memory Alloy (SMA) actuation technology is a candidate method for reducing weight and power requirements for inlet flow control actuators in prospective supersonic passenger aircraft. The high speed/high Mach operating points of such aircraft can also call for the use of High Temperature SMAs, with transition temperatures beyond those of typical binary NiTi alloys. This paper outlines a demonstration project that entailed both testing and assessment of newly developed NiTiPt HTSMAs, as well as their use in an actuation application representative of inlet configurations. The project featured benchtop testing of an HTSMA-actuated ramp model as well as experiments in a high speed wind tunnel at loads representative of supersonic conditions. The ability of the model to generate adequate force and actuation stroke for this application is encouraging evidence the feasibility of NiTiPt-based devices for inlet flow control.

Towards an integrated model of floodplain hydrology representing feedbacks and anthropogenic effects

NASA Astrophysics Data System (ADS)

Andreadis, K.; Schumann, G.; Voisin, N.; O'Loughlin, F.; Tesfa, T. K.; Bates, P.

2017-12-01

The exchange of water between hillslopes, river channels and floodplain can be quite complex and the difficulty in capturing the mechanisms behind it is exacerbated by the impact of human activities such as irrigation and reservoir operations. Although there has been a vast body of work on modeling hydrological processes, most of the resulting models have been limited with regards to aspects of the coupled human-natural system. For example, hydrologic models that represent processes such as evapotranspiration, infiltration, interception and groundwater dynamics often neglect anthropogenic effects or do not adequately represent the inherently two-dimensional floodplain flow. We present an integrated modeling framework that is comprised of the Variable Infiltration Capacity (VIC) hydrology model, the LISFLOOD-FP hydrodynamic model, and the Water resources Management (WM) model. The VIC model solves the energy and water balance over a gridded domain and simulates a number of hydrologic features such as snow, frozen soils, lakes and wetlands, while also representing irrigation demand from cropland areas. LISFLOOD-FP solves an approximation of the Saint-Venant equations to efficiently simulate flow in river channels and the floodplain. The implementation of WM accommodates a variety of operating rules in reservoirs and withdrawals due to consumptive demands, allowing the successful simulation of regulated flow. The models are coupled so as to allow feedbacks between their corresponding processes, therefore providing the ability to test different hypotheses about the floodplain hydrology of large-scale basins. We test this integrated framework over the Zambezi River basin by simulating its hydrology from 2000-2010, and evaluate the results against remotely sensed observations. Finally, we examine the sensitivity of streamflow and water inundation to changes in reservoir operations, precipitation and temperature.

An in vitro model of infection of chicken embryos by Cryptosporidium baileyi.

PubMed

Huang, Lei; Zhu, Huili; Zhang, Sumei; Wang, Rongjun; Liu, Limin; Jian, Fuchun; Ning, Changshen; Zhang, Longxian

2014-12-01

Cryptosporidiosis is one of the most prevalent parasitic infections in domesticated, caged and wild birds. Cryptosporidium baileyi is the most common species reported in a wide range of avian hosts. Although this parasite is well investigated, there is no adequate in vitro model for its endogenous development, and therefore, knowledge of each life cycle phase is scarce. In the present study, an in vitro model for C. baileyi in chicken embryos was developed and the complete life cycle investigated by light and electron microscopy, including both the sexual and asexual reproduction stages. The complete life cycle of C. baileyi was observed during 1-96 h post inoculation (PI), and the average reproduction number of C. baileyi oocysts in allantoic fluid of each chicken embryo was greatest at 168 h PI. These results suggest that chicken embryos could adequately represent the natural host cells and support the development of all the endogenous life cycle stages of C. baileyi, and also provide a new and effective in vitro cultivation system for further studies on antigens, virulence, infectivity, metabolites, and sensitivity of drugs against parasites. Copyright © 2014 Elsevier Inc. All rights reserved.

A model for foam formation, stability, and breakdown in glass-melting furnaces.

PubMed

van der Schaaf, John; Beerkens, Ruud G C

2006-03-01

A dynamic model for describing the build-up and breakdown of a glass-melt foam is presented. The foam height is determined by the gas flux to the glass-melt surface and the drainage rate of the liquid lamellae between the gas bubbles. The drainage rate is determined by the average gas bubble radius and the physical properties of the glass melt: density, viscosity, surface tension, and interfacial mobility. Neither the assumption of a fully mobile nor the assumption of a fully immobile glass-melt interface describe the observed foam formation on glass melts adequately. The glass-melt interface appears partially mobile due to the presence of surface active species, e.g., sodium sulfate and silanol groups. The partial mobility can be represented by a single, glass-melt composition specific parameter psi. The value of psi can be estimated from gas bubble lifetime experiments under furnace conditions. With this parameter, laboratory experiments of foam build-up and breakdown in a glass melt are adequately described, qualitatively and quantitatively by a set of ordinary differential equations. An approximate explicit relationship for the prediction of the steady-state foam height is derived from the fundamental model.

Generalized first-order kinetic model for biosolids decomposition and oxidation during hydrothermal treatment.

PubMed

Shanableh, A

2005-01-01

The main objective of this study was to develop generalized first-order kinetic models to represent hydrothermal decomposition and oxidation of biosolids within a wide range of temperatures (200-450 degrees C). A lumping approach was used in which oxidation of the various organic ingredients was characterized by the chemical oxygen demand (COD), and decomposition was characterized by the particulate (i.e., nonfilterable) chemical oxygen demand (PCOD). Using the Arrhenius equation (k = k(o)e(-Ea/RT)), activation energy (Ea) levels were derived from 42 continuous-flow hydrothermal treatment experiments conducted at temperatures in the range of 200-450 degrees C. Using predetermined values for k(o) in the Arrhenius equation, the activation energies of the various organic ingredients were separated into 42 values for oxidation and a similar number for decomposition. The activation energy values were then classified into levels representing the relative ease at which the organic ingredients of the biosolids were oxidized or decomposed. The resulting simple first-order kinetic models adequately represented, within the experimental data range, hydrothermal decomposition of the organic particles as measured by PCOD and oxidation of the organic content as measured by COD. The modeling approach presented in the paper provide a simple and general framework suitable for assessing the relative reaction rates of the various organic ingredients of biosolids.

Human-robot interaction modeling and simulation of supervisory control and situational awareness during field experimentation with military manned and unmanned ground vehicles

NASA Astrophysics Data System (ADS)

Johnson, Tony; Metcalfe, Jason; Brewster, Benjamin; Manteuffel, Christopher; Jaswa, Matthew; Tierney, Terrance

2010-04-01

The proliferation of intelligent systems in today's military demands increased focus on the optimization of human-robot interactions. Traditional studies in this domain involve large-scale field tests that require humans to operate semiautomated systems under varying conditions within military-relevant scenarios. However, provided that adequate constraints are employed, modeling and simulation can be a cost-effective alternative and supplement. The current presentation discusses a simulation effort that was executed in parallel with a field test with Soldiers operating military vehicles in an environment that represented key elements of the true operational context. In this study, "constructive" human operators were designed to represent average Soldiers executing supervisory control over an intelligent ground system. The constructive Soldiers were simulated performing the same tasks as those performed by real Soldiers during a directly analogous field test. Exercising the models in a high-fidelity virtual environment provided predictive results that represented actual performance in certain aspects, such as situational awareness, but diverged in others. These findings largely reflected the quality of modeling assumptions used to design behaviors and the quality of information available on which to articulate principles of operation. Ultimately, predictive analyses partially supported expectations, with deficiencies explicable via Soldier surveys, experimenter observations, and previously-identified knowledge gaps.

3D digital headform models of Australian cyclists.

PubMed

Ellena, Thierry; Skals, Sebastian; Subic, Aleksandar; Mustafa, Helmy; Pang, Toh Yen

2017-03-01

Traditional 1D anthropometric data have been the primary source of information used by ergonomists for the dimensioning of head and facial gear. Although these data are simple to use and understand, they only provide univariate measures of key dimensions. 3D anthropometric data, however, describe the complete shape characteristics of the head surface, but are complicated to interpret due to the abundance of information they contain. Consequently, current headform standards based on 1D measurements may not adequately represent the actual head shape variations of the intended user groups. The purpose of this study was to introduce a set of new digital headform models representative of the adult cyclists' community in Australia. Four models were generated based on an Australian 3D anthropometric database of head shapes and a modified hierarchical clustering algorithm. Considerable shape differences were identified between our models and the current headforms from the Australian standard. We conclude that the design of head and facial gear based on current standards might not be favorable for optimal fitting results. Copyright © 2016 Elsevier Ltd. All rights reserved.

Psychometric properties of the Spanish version of the UPPS-P Impulsive Behavior Scale: A Rasch rating scale analysis and confirmatory factor analysis.

PubMed

Pilatti, Angelina; Lozano, Oscar M; Cyders, Melissa A

2015-12-01

The present study was aimed at determining the psychometric properties of the Spanish version of the UPPS-P Impulsive Behavior Scale in a sample of college students. Participants were 318 college students (36.2% men; mean age = 20.9 years, SD = 6.4 years). The psychometric properties of this Spanish version were analyzed using the Rasch model, and the factor structure was examined using confirmatory factor analysis. The verification of the global fit of the data showed adequate indexes for persons and items. The reliability estimates were high for both items and persons. Differential item functioning across gender was found for 23 items, which likely reflects known differences in impulsivity levels between men and women. The factor structure of the Spanish version of the UPPS-P replicates previous work with the original UPPS-P Scale. Overall, results suggest that test scores from the Spanish version of the UPPS-P show adequate psychometric properties to accurately assess the multidimensional model of impulsivity, which represents the most exhaustive measure of this construct. (c) 2015 APA, all rights reserved).

Children's Needs -- for Universal Food Service and Nutrition.

ERIC Educational Resources Information Center

Briggs, George M.

Good nutrition and adequate nutritious food are not only essential to good health but also represent the difference between life and death. Nutrition is the world's number one problem today, along with war and population control. Good nutrition means providing, with care and love, all 45 essential nutrients in adequate amounts to each child -- one…

Number of women faculty in the geosciences increasing, but slowly

NASA Astrophysics Data System (ADS)

Wolfe, Cecily J.

Why are there so few women faculty in the geosciences, while there are large numbers of women undergraduate and graduate students? According to National Science Foundation (NSF) estimates [e.g.,NSF, 1996] for 1995 in the Earth, atmospheric, and oceanic sciences, women made up 34% of the bachelor's degrees awarded, 35% of the graduate students enrolled, and 22% of the doctorates granted. Yet progress has been slower in achieving adequate representation of women geoscientists in academia, where women represent only 12% of the faculty. The barriers confronting the advancement of women scientists are complex and difficult to unravel. Proposed factors include cultural stereotypes, childhood socialization, lack of women mentors and role models, lack of critical mass, family responsibilities, dual-career-couple status, isolation from collegial networks, different research and publishing strategy, and less adequate access to institutional resources [c.f., Widnall, 1988; Zuckerman et al., 1991].

Consideration in selecting crops for the human-rated life support system: a Linear Programming model

NASA Technical Reports Server (NTRS)

Wheeler, E. F.; Kossowski, J.; Goto, E.; Langhans, R. W.; White, G.; Albright, L. D.; Wilcox, D.; Henninger, D. L. (Principal Investigator)

1996-01-01

A Linear Programming model has been constructed which aids in selecting appropriate crops for CELSS (Controlled Environment Life Support System) food production. A team of Controlled Environment Agriculture (CEA) faculty, staff, graduate students and invited experts representing more than a dozen disciplines, provided a wide range of expertise in developing the model and the crop production program. The model incorporates nutritional content and controlled-environment based production yields of carefully chosen crops into a framework where a crop mix can be constructed to suit the astronauts' needs. The crew's nutritional requirements can be adequately satisfied with only a few crops (assuming vitamin mineral supplements are provided) but this will not be satisfactory from a culinary standpoint. This model is flexible enough that taste and variety driven food choices can be built into the model.

Consideration in selecting crops for the human-rated life support system: a linear programming model

NASA Astrophysics Data System (ADS)

Wheeler, E. F.; Kossowski, J.; Goto, E.; Langhans, R. W.; White, G.; Albright, L. D.; Wilcox, D.

A Linear Programming model has been constructed which aids in selecting appropriate crops for CELSS (Controlled Environment Life Support System) food production. A team of Controlled Environment Agriculture (CEA) faculty, staff, graduate students and invited experts representing more than a dozen disciplines, provided a wide range of expertise in developing the model and the crop production program. The model incorporates nutritional content and controlled-environment based production yields of carefully chosen crops into a framework where a crop mix can be constructed to suit the astronauts' needs. The crew's nutritional requirements can be adequately satisfied with only a few crops (assuming vitamin mineral supplements are provided) but this will not be satisfactory from a culinary standpoint. This model is flexible enough that taste and variety driven food choices can be built into the model.

Accuracy of methods for calculating volumetric wear from coordinate measuring machine data of retrieved metal-on-metal hip joint implants.

PubMed

Lu, Zhen; McKellop, Harry A

2014-03-01

This study compared the accuracy and sensitivity of several numerical methods employing spherical or plane triangles for calculating the volumetric wear of retrieved metal-on-metal hip joint implants from coordinate measuring machine measurements. Five methods, one using spherical triangles and four using plane triangles to represent the bearing and the best-fit surfaces, were assessed and compared on a perfect hemisphere model and a hemi-ellipsoid model (i.e. unworn models), computer-generated wear models and wear-tested femoral balls, with point spacings of 0.5, 1, 2 and 3 mm. The results showed that the algorithm (Method 1) employing spherical triangles to represent the bearing surface and to scale the mesh to the best-fit surfaces produced adequate accuracy for the wear volume with point spacings of 0.5, 1, 2 and 3 mm. The algorithms (Methods 2-4) using plane triangles to represent the bearing surface and to scale the mesh to the best-fit surface also produced accuracies that were comparable to that with spherical triangles. In contrast, if the bearing surface was represented with a mesh of plane triangles and the best-fit surface was taken as a smooth surface without discretization (Method 5), the algorithm produced much lower accuracy with a point spacing of 0.5 mm than Methods 1-4 with a point spacing of 3 mm.

Contemporary Aspects of Marketing in Clinical Trials Including Segments of IT and Technology Transfer

PubMed Central

Stamenovic, Milorad; Dobraca, Amra; Smajlovic, Mersiha

2018-01-01

Introduction: The aim of this paper is to present the marketing strategy and the application of management (marketing management) and advertising in order to increase the efficiency of innovative approach in clinical trials that include and involve the use of new technologies and transfer of technologies. Material and Methods: This paper has a descriptive character and represents a narrative review of the literature and new model implementation. Results: Marketing models are primarily used to improve the inclusion of a larger (and appropriate) number of patients, but they can be credited for the stay and monitoring of patients in the trial. Regulatory mechanisms play an important role in the application of various marketing strategies within clinical trials. The value for the patient as the most important stakeholder is defined in the field of clinical trials according to Kotler’s value model for the consumer. Conclusion: In order to achieve the best results it is important to adequately examine all the elements of clinical trials and apply this knowledge in creation of a marketing plan that will be made in accordance with the legal regulations defined globally and locally. In this paper, two challenges have been highlighted for the adequate application of marketing tools in the field of clinical trials, namely: defining business elements in order to provide an adequate marketing approach for clinical trials and technology transfer and ensuring uniformity and regulatory affirmation of marketing attitudes in clinical trials in all regions in which they are carried out in accordance with ICH-GCP and valid regulations. PMID:29719318

The polygonal model: A simple representation of biomolecules as a tool for teaching metabolism.

PubMed

Bonafe, Carlos Francisco Sampaio; Bispo, Jose Ailton Conceição; de Jesus, Marcelo Bispo

2018-01-01

Metabolism involves numerous reactions and organic compounds that the student must master to understand adequately the processes involved. Part of biochemical learning should include some knowledge of the structure of biomolecules, although the acquisition of such knowledge can be time-consuming and may require significant effort from the student. In this report, we describe the "polygonal model" as a new means of graphically representing biomolecules. This model is based on the use of geometric figures such as open triangles, squares, and circles to represent hydroxyl, carbonyl, and carboxyl groups, respectively. The usefulness of the polygonal model was assessed by undergraduate students in a classroom activity that consisted of "transforming" molecules from Fischer models to polygonal models and vice and versa. The survey was applied to 135 undergraduate Biology and Nursing students. Students found the model easy to use and we noted that it allowed identification of students' misconceptions in basic concepts of organic chemistry, such as in stereochemistry and organic groups that could then be corrected. The students considered the polygonal model easier and faster for representing molecules than Fischer representations, without loss of information. These findings indicate that the polygonal model can facilitate the teaching of metabolism when the structures of biomolecules are discussed. Overall, the polygonal model promoted contact with chemical structures, e.g. through drawing activities, and encouraged student-student dialog, thereby facilitating biochemical learning. © 2017 by The International Union of Biochemistry and Molecular Biology, 46(1):66-75, 2018. © 2017 The International Union of Biochemistry and Molecular Biology.

Ensuring the Right to Minimally Adequate Habilitation: A Proposed Role for Human Rights Committees.

ERIC Educational Resources Information Center

Reese, R. Matthew

1984-01-01

The article suggests a role for Human Rights Committees in monitoring programs for mentally retarded persons in terms of whether the goals and objectives are adequate and whether the habilitation procedures represent a reasonable balance between intrusiveness and effectiveness and are being employed as indicated in the habilitation plan.…

Sediment acoustic index method for computing continuous suspended-sediment concentrations

USGS Publications Warehouse

Landers, Mark N.; Straub, Timothy D.; Wood, Molly S.; Domanski, Marian M.

2016-07-11

Once developed, sediment acoustic index ratings must be validated with additional suspended-sediment samples, beyond the period of record used in the rating development, to verify that the regression model continues to adequately represent sediment conditions within the stream. Changes in ADVM configuration or installation, or replacement with another ADVM, may require development of a new rating. The best practices described in this report can be used to develop continuous estimates of suspended-sediment concentration and load using sediment acoustic surrogates to enable more informed and accurate responses to diverse sedimentation issues.

Evaluation of the CEAS model for barley yields in North Dakota and Minnesota

NASA Technical Reports Server (NTRS)

Barnett, T. L. (Principal Investigator)

1981-01-01

The CEAS yield model is based upon multiple regression analysis at the CRD and state levels. For the historical time series, yield is regressed on a set of variables derived from monthly mean temperature and monthly precipitation. Technological trend is represented by piecewise linear and/or quadriatic functions of year. Indicators of yield reliability obtained from a ten-year bootstrap test (1970-79) demonstrated that biases are small and performance as indicated by the root mean square errors are acceptable for intended application, however, model response for individual years particularly unusual years, is not very reliable and shows some large errors. The model is objective, adequate, timely, simple and not costly. It considers scientific knowledge on a broad scale but not in detail, and does not provide a good current measure of modeled yield reliability.

Posttest Analyses of the Steel Containment Vessel Model

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

Costello, J.F.; Hessheimer, M.F.; Ludwigsen, J.S.

A high pressure test of a scale model of a steel containment vessel (SCV) was conducted on December 11-12, 1996 at Sandia National Laboratories, Albuquerque, NM, USA. The test model is a mixed-scaled model (1:10 in geometry and 1:4 in shell thickness) of an improved Mark II boiling water reactor (BWR) containment. This testis part of a program to investigate the response of representative models of nuclear containment structures to pressure loads beyond the design basis accident. The posttest analyses of this test focused on three areas where the pretest analysis effort did not adequately predict the model behavior duringmore » the test. These areas are the onset of global yielding, the strain concentrations around the equipment hatch and the strain concentrations that led to a small tear near a weld relief opening that was not modeled in the pretest analysis.« less

Service Modeling Language Applied to Critical Infrastructure

NASA Astrophysics Data System (ADS)

Baldini, Gianmarco; Fovino, Igor Nai

The modeling of dependencies in complex infrastructure systems is still a very difficult task. Many methodologies have been proposed, but a number of challenges still remain, including the definition of the right level of abstraction, the presence of different views on the same critical infrastructure and how to adequately represent the temporal evolution of systems. We propose a modeling methodology where dependencies are described in terms of the service offered by the critical infrastructure and its components. The model provides a clear separation between services and the underlying organizational and technical elements, which may change in time. The model uses the Service Modeling Language proposed by the W3 consortium for describing critical infrastructure in terms of interdependent services nodes including constraints, behavior, information flows, relations, rules and other features. Each service node is characterized by its technological, organizational and process components. The model is then applied to a real case of an ICT system for users authentication.

Current Challenges for Healthcare Services and the Opportunities Created by the Marketing Abilities

PubMed Central

Purcărea, T; Purcărea, LV; Raţiu, M

2008-01-01

Life is changing dramatically, market position as part of life is becoming more and more important, and marketing, considered a key cultural architect of nowadays that involves voluntary relation exchanges between the communicating partners, is placing the patient in the center of most adequate action towards the medical future which represents his life quality. We think that the moment has come to resort to marketing as a new method to identify innovation opportunities in healthcare services' delivery, considering that the high quality of healthcare services, answering to demands of healthcare systems' consumers, represents a well recognized priority for the European citizens. Consequently, the model of ‘healthcare business’ has to rely on the value for patient by creating competition concerning the results at medical condition level. PMID:20108474

The relationship between trading volumes, number of transactions, and stock volatility in GARCH models

NASA Astrophysics Data System (ADS)

Takaishi, Tetsuya; Chen, Ting Ting

2016-08-01

We examine the relationship between trading volumes, number of transactions, and volatility using daily stock data of the Tokyo Stock Exchange. Following the mixture of distributions hypothesis, we use trading volumes and the number of transactions as proxy for the rate of information arrivals affecting stock volatility. The impact of trading volumes or number of transactions on volatility is measured using the generalized autoregressive conditional heteroscedasticity (GARCH) model. We find that the GARCH effects, that is, persistence of volatility, is not always removed by adding trading volumes or number of transactions, indicating that trading volumes and number of transactions do not adequately represent the rate of information arrivals.

Impacts of variability in geomechanical properties on hydrate bearing sediment responses

NASA Astrophysics Data System (ADS)

Lin, J. S.; Uchida, S.; Choi, J. H.; Seol, Y.

2017-12-01

Hydrate bearing sediments (HBS) may become unstable during the gas production operation, or from natural processes such as change in the landform or temperature. The geomechanical modeling is a rational way to assess HBS stability regardless of the process involved. At the present time, such modeling is laced with uncertainties. The uncertainties come from many sources that include the adequacy of a modeling framework to accurately project the response of HBS, the gap in the available field information, and the variability in the laboratory test results from limited samples. For a reasonable stability assessment, the impact of the various uncertainties have to be addressed. This study looks into one particular aspect of the uncertainty, namely, the uncertainty caused by the scatter in the laboratory tests and the ability of a constitutive model to adequately represent them. Specifically this study focuses on the scatter in the results from laboratory tests on high quality pressured core samples from a marine site, and use a critical state constitutive model to represent them. The study investigates how the HBS responses shift when the parameters of the constitutive model are varied to reflect the different aspects of experimental results. Also investigated are impacts on the responses by altering certain formulations of the constitutive model to suit particular sets of results.

New approaches to quantifying aerosol influence on the cloud radiative effect

DOE PAGES

Feingold, Graham; McComiskey, Allison; Yamaguchi, Takanobu; ...

2016-02-01

The topic of cloud radiative forcing associated with the atmospheric aerosol has been the focus of intense scrutiny for decades. The enormity of the problem is reflected in the need to understand aspects such as aerosol composition, optical properties, cloud condensation, and ice nucleation potential, along with the global distribution of these properties, controlled by emissions, transport, transformation, and sinks. Equally daunting is that clouds themselves are complex, turbulent, microphysical entities and, by their very nature, ephemeral and hard to predict. Atmospheric general circulation models represent aerosol–cloud interactions at ever-increasing levels of detail, but these models lack the resolution tomore » represent clouds and aerosol–cloud interactions adequately. There is a dearth of observational constraints on aerosol–cloud interactions. In this paper, we develop a conceptual approach to systematically constrain the aerosol–cloud radiative effect in shallow clouds through a combination of routine process modeling and satellite and surface-based shortwave radiation measurements. Finally, we heed the call to merge Darwinian and Newtonian strategies by balancing microphysical detail with scaling and emergent properties of the aerosol–cloud radiation system.« less

New approaches to quantifying aerosol influence on the cloud radiative effect

PubMed Central

Feingold, Graham; McComiskey, Allison; Yamaguchi, Takanobu; Johnson, Jill S.; Carslaw, Kenneth S.; Schmidt, K. Sebastian

2016-01-01

The topic of cloud radiative forcing associated with the atmospheric aerosol has been the focus of intense scrutiny for decades. The enormity of the problem is reflected in the need to understand aspects such as aerosol composition, optical properties, cloud condensation, and ice nucleation potential, along with the global distribution of these properties, controlled by emissions, transport, transformation, and sinks. Equally daunting is that clouds themselves are complex, turbulent, microphysical entities and, by their very nature, ephemeral and hard to predict. Atmospheric general circulation models represent aerosol−cloud interactions at ever-increasing levels of detail, but these models lack the resolution to represent clouds and aerosol−cloud interactions adequately. There is a dearth of observational constraints on aerosol−cloud interactions. We develop a conceptual approach to systematically constrain the aerosol−cloud radiative effect in shallow clouds through a combination of routine process modeling and satellite and surface-based shortwave radiation measurements. We heed the call to merge Darwinian and Newtonian strategies by balancing microphysical detail with scaling and emergent properties of the aerosol−cloud radiation system. PMID:26831092

Live Cell Imaging of Viscosity in 3D Tumour Cell Models.

PubMed

Shirmanova, Marina V; Shimolina, Lubov' E; Lukina, Maria M; Zagaynova, Elena V; Kuimova, Marina K

2017-01-01

Abnormal levels of viscosity in tissues and cells are known to be associated with disease and malfunction. While methods to measure bulk macroscopic viscosity of bio-tissues are well developed, imaging viscosity at the microscopic scale remains a challenge, especially in vivo. Molecular rotors are small synthetic viscosity-sensitive fluorophores in which fluorescence parameters are strongly correlated to the microviscosity of their immediate environment. Hence, molecular rotors represent a promising instrument for mapping of viscosity in living cells and tissues at the microscopic level. Quantitative measurements of viscosity can be achieved by recording time-resolved fluorescence decays of molecular rotor using fluorescence lifetime imaging microscopy (FLIM), which is also suitable for dynamic viscosity mapping, both in cellulo and in vivo. Among tools of experimental oncology, 3D tumour cultures, or spheroids, are considered a more adequate in vitro model compared to a cellular monolayer, and represent a less labour-intensive and more unified approach compared to animal tumour models. This chapter describes a methodology for microviscosity imaging in tumour spheroids using BODIPY-based molecular rotors and two photon-excited FLIM.

New approaches to quantifying aerosol influence on the cloud radiative effect.

PubMed

Feingold, Graham; McComiskey, Allison; Yamaguchi, Takanobu; Johnson, Jill S; Carslaw, Kenneth S; Schmidt, K Sebastian

2016-05-24

The topic of cloud radiative forcing associated with the atmospheric aerosol has been the focus of intense scrutiny for decades. The enormity of the problem is reflected in the need to understand aspects such as aerosol composition, optical properties, cloud condensation, and ice nucleation potential, along with the global distribution of these properties, controlled by emissions, transport, transformation, and sinks. Equally daunting is that clouds themselves are complex, turbulent, microphysical entities and, by their very nature, ephemeral and hard to predict. Atmospheric general circulation models represent aerosol-cloud interactions at ever-increasing levels of detail, but these models lack the resolution to represent clouds and aerosol-cloud interactions adequately. There is a dearth of observational constraints on aerosol-cloud interactions. We develop a conceptual approach to systematically constrain the aerosol-cloud radiative effect in shallow clouds through a combination of routine process modeling and satellite and surface-based shortwave radiation measurements. We heed the call to merge Darwinian and Newtonian strategies by balancing microphysical detail with scaling and emergent properties of the aerosol-cloud radiation system.

[Urinary tract infections: Economical impact of water intake].

PubMed

Bruyère, F; Buendia-Jiménez, I; Cosnefroy, A; Lenoir-Wijnkoop, I; Tack, I; Molinier, L; Daudon, M; Nuijten, M J C

2015-09-01

This study aims to estimate the impact of preventing urinary tract infections (UTI), using a strategy of increased water intake, from the payer's perspective in the French health care system. A Markov model enables a comparison of health care costs and outcomes for a virtual cohort of subjects with different levels of daily water intake. The analysis of the budgetary impact was based on a period of 5years. The analysis was based on a 25-year follow-up period to assess the effects of adequate water supply on long-term complications. The authors estimate annual primary incidence of UTI and annual risk of recurrence at 5.3% and 30%, respectively. Risk reduction associated with greater water intake reached 45% and 33% for the general and recurrent populations, respectively. The average total health care cost of a single UTI episode is €1074; for a population of 65 millions, UTI management represents a cost of €3.700 millions for payers. With adequate water intake, the model indicates a potential cost savings of €2.288 millions annually, by preventing 27 million UTI episodes. At the individual level, the potential cost savings is approximately €2915. Preventing urinary tract infections using a strategy of adequate water intake could lead to significant cost savings for a public health care system. Further studies are needed to assess the effectiveness of such an approach. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Conceptualization of the Sexual Response Models in Men: Are there Differences Between Sexually Functional and Dysfunctional Men?

PubMed

Connaughton, Catherine; McCabe, Marita; Karantzas, Gery

2016-03-01

Research to validate models of sexual response empirically in men with and without sexual dysfunction (MSD), as currently defined, is limited. To explore the extent to which the traditional linear or the Basson circular model best represents male sexual response for men with MSD and sexually functional men. In total, 573 men completed an online questionnaire to assess sexual function and aspects of the models of sexual response. In total, 42.2% of men (242) were sexually functional, and 57.8% (331) had at least one MSD. Models were built and tested using bootstrapping and structural equation modeling. Fit of models for men with and without MSD. The linear model and the initial circular model were a poor fit for men with and without MSD. A modified version of the circular model demonstrated adequate fit for the two groups and showed important interactions between psychological factors and sexual response for men with and without MSD. Male sexual response was not represented by the linear model for men with or without MSD, excluding possible healthy responsive desire. The circular model provided a better fit for the two groups of men but demonstrated that the relations between psychological factors and phases of sexual response were different for men with and without MSD as currently defined. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

Alternative ways of using field-based estimates to calibrate ecosystem models and their implications for carbon cycle studies

USGS Publications Warehouse

He, Yujie; Zhuang, Qianlai; McGuire, David; Liu, Yaling; Chen, Min

2013-01-01

Model-data fusion is a process in which field observations are used to constrain model parameters. How observations are used to constrain parameters has a direct impact on the carbon cycle dynamics simulated by ecosystem models. In this study, we present an evaluation of several options for the use of observations in modeling regional carbon dynamics and explore the implications of those options. We calibrated the Terrestrial Ecosystem Model on a hierarchy of three vegetation classification levels for the Alaskan boreal forest: species level, plant-functional-type level (PFT level), and biome level, and we examined the differences in simulated carbon dynamics. Species-specific field-based estimates were directly used to parameterize the model for species-level simulations, while weighted averages based on species percent cover were used to generate estimates for PFT- and biome-level model parameterization. We found that calibrated key ecosystem process parameters differed substantially among species and overlapped for species that are categorized into different PFTs. Our analysis of parameter sets suggests that the PFT-level parameterizations primarily reflected the dominant species and that functional information of some species were lost from the PFT-level parameterizations. The biome-level parameterization was primarily representative of the needleleaf PFT and lost information on broadleaf species or PFT function. Our results indicate that PFT-level simulations may be potentially representative of the performance of species-level simulations while biome-level simulations may result in biased estimates. Improved theoretical and empirical justifications for grouping species into PFTs or biomes are needed to adequately represent the dynamics of ecosystem functioning and structure.

ATR architecture for multisensor fusion

NASA Astrophysics Data System (ADS)

Hamilton, Mark K.; Kipp, Teresa A.

1996-06-01

The work of the U.S. Army Research Laboratory (ARL) in the area of algorithms for the identification of static military targets in single-frame electro-optical (EO) imagery has demonstrated great potential in platform-based automatic target identification (ATI). In this case, the term identification is used to mean being able to tell the difference between two military vehicles -- e.g., the M60 from the T72. ARL's work includes not only single-sensor forward-looking infrared (FLIR) ATI algorithms, but also multi-sensor ATI algorithms. We briefly discuss ARL's hybrid model-based/data-learning strategy for ATI, which represents a significant step forward in ATI algorithm design. For example, in the case of single sensor FLIR it allows the human algorithm designer to build directly into the algorithm knowledge that can be adequately modeled at this time, such as the target geometry which directly translates into the target silhouette in the FLIR realm. In addition, it allows structure that is not currently well understood (i.e., adequately modeled) to be incorporated through automated data-learning algorithms, which in a FLIR directly translates into an internal thermal target structure signature. This paper shows the direct applicability of this strategy to both the single-sensor FLIR as well as the multi-sensor FLIR and laser radar.

Hierarchical Heteroclinics in Dynamical Model of Cognitive Processes: Chunking

NASA Astrophysics Data System (ADS)

Afraimovich, Valentin S.; Young, Todd R.; Rabinovich, Mikhail I.

Combining the results of brain imaging and nonlinear dynamics provides a new hierarchical vision of brain network functionality that is helpful in understanding the relationship of the network to different mental tasks. Using these ideas it is possible to build adequate models for the description and prediction of different cognitive activities in which the number of variables is usually small enough for analysis. The dynamical images of different mental processes depend on their temporal organization and, as a rule, cannot be just simple attractors since cognition is characterized by transient dynamics. The mathematical image for a robust transient is a stable heteroclinic channel consisting of a chain of saddles connected by unstable separatrices. We focus here on hierarchical chunking dynamics that can represent several cognitive activities. Chunking is the dynamical phenomenon that means dividing a long information chain into shorter items. Chunking is known to be important in many processes of perception, learning, memory and cognition. We prove that in the phase space of the model that describes chunking there exists a new mathematical object — heteroclinic sequence of heteroclinic cycles — using the technique of slow-fast approximations. This new object serves as a skeleton of motions reflecting sequential features of hierarchical chunking dynamics and is an adequate image of the chunking processing.

Approach for environmental baseline water sampling

USGS Publications Warehouse

Smith, K.S.

2011-01-01

Samples collected during the exploration phase of mining represent baseline conditions at the site. As such, they can be very important in forecasting potential environmental impacts should mining proceed, and can become measurements against which future changes are compared. Constituents in stream water draining mined and mineralized areas tend to be geochemically, spatially, and temporally variable, which presents challenges in collecting both exploration and baseline water-quality samples. Because short-term (daily) variations can complicate long-term trends, it is important to consider recent findings concerning geochemical variability of stream-water constituents at short-term timescales in designing sampling plans. Also, adequate water-quality information is key to forecasting potential ecological impacts from mining. Therefore, it is useful to collect baseline water samples adequate tor geochemical and toxicological modeling. This requires complete chemical analyses of dissolved constituents that include major and minor chemical elements as well as physicochemical properties (including pH, specific conductance, dissolved oxygen) and dissolved organic carbon. Applying chemical-equilibrium and appropriate toxicological models to water-quality information leads to an understanding of the speciation, transport, sequestration, bioavailability, and aquatic toxicity of potential contaminants. Insights gained from geochemical and toxicological modeling of water-quality data can be used to design appropriate mitigation and for economic planning for future mining activities.

A hybrid finite-difference and analytic element groundwater model

USGS Publications Warehouse

Haitjema, Henk M.; Feinstein, Daniel T.; Hunt, Randall J.; Gusyev, Maksym

2010-01-01

Regional finite-difference models tend to have large cell sizes, often on the order of 1–2 km on a side. Although the regional flow patterns in deeper formations may be adequately represented by such a model, the intricate surface water and groundwater interactions in the shallower layers are not. Several stream reaches and nearby wells may occur in a single cell, precluding any meaningful modeling of the surface water and groundwater interactions between the individual features. We propose to replace the upper MODFLOW layer or layers, in which the surface water and groundwater interactions occur, by an analytic element model (GFLOW) that does not employ a model grid; instead, it represents wells and surface waters directly by the use of point-sinks and line-sinks. For many practical cases it suffices to provide GFLOW with the vertical leakage rates calculated in the original coarse MODFLOW model in order to obtain a good representation of surface water and groundwater interactions. However, when the combined transmissivities in the deeper (MODFLOW) layers dominate, the accuracy of the GFLOW solution diminishes. For those cases, an iterative coupling procedure, whereby the leakages between the GFLOW and MODFLOW model are updated, appreciably improves the overall solution, albeit at considerable computational cost. The coupled GFLOW–MODFLOW model is applicable to relatively large areas, in many cases to the entire model domain, thus forming an attractive alternative to local grid refinement or inset models.

76 FR 71573 - Medicare Program; Request for Nominations for Members for the Medicare Evidence Development...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-18

... individual qualifications and not as representatives of professional associations or societies. We wish to... subspecialties, administrative medicine, public health, biological and physical sciences, epidemiology and... as representatives of professional associations or societies. We wish to ensure adequate...

Proposal of Constraints Analysis Method Based on Network Model for Task Planning

NASA Astrophysics Data System (ADS)

Tomiyama, Tomoe; Sato, Tatsuhiro; Morita, Toyohisa; Sasaki, Toshiro

Deregulation has been accelerating several activities toward reengineering business processes, such as railway through service and modal shift in logistics. Making those activities successful, business entities have to regulate new business rules or know-how (we call them ‘constraints’). According to the new constraints, they need to manage business resources such as instruments, materials, workers and so on. In this paper, we propose a constraint analysis method to define constraints for task planning of the new business processes. To visualize each constraint's influence on planning, we propose a network model which represents allocation relations between tasks and resources. The network can also represent task ordering relations and resource grouping relations. The proposed method formalizes the way of defining constraints manually as repeatedly checking the network structure and finding conflicts between constraints. Being applied to crew scheduling problems shows that the method can adequately represent and define constraints of some task planning problems with the following fundamental features, (1) specifying work pattern to some resources, (2) restricting the number of resources for some works, (3) requiring multiple resources for some works, (4) prior allocation of some resources to some works and (5) considering the workload balance between resources.

Evaluation of the Williams-type model for barley yields in North Dakota and Minnesota

NASA Technical Reports Server (NTRS)

Barnett, T. L. (Principal Investigator)

1981-01-01

The Williams-type yield model is based on multiple regression analysis of historial time series data at CRD level pooled to regional level (groups of similar CRDs). Basic variables considered in the analysis include USDA yield, monthly mean temperature, monthly precipitation, soil texture and topographic information, and variables derived from these. Technologic trend is represented by piecewise linear and/or quadratic functions of year. Indicators of yield reliability obtained from a ten-year bootstrap test (1970-1979) demonstrate that biases are small and performance based on root mean square appears to be acceptable for the intended AgRISTARS large area applications. The model is objective, adequate, timely, simple, and not costly. It consideres scientific knowledge on a broad scale but not in detail, and does not provide a good current measure of modeled yield reliability.

Short-stack modeling of degradation in solid oxide fuel cells. Part I. Contact degradation

NASA Astrophysics Data System (ADS)

Gazzarri, J. I.; Kesler, O.

As the first part of a two paper series, we present a two-dimensional impedance model of a working solid oxide fuel cell (SOFC) to study the effect of contact degradation on the impedance spectrum for the purpose of non-invasive diagnosis. The two dimensional modeled geometry includes the ribbed interconnect, and is adequate to represent co- and counter-flow configurations. Simulated degradation modes include: cathode delamination, interconnect oxidation, and interconnect-cathode detachment. The simulations show differences in the way each degradation mode impacts the impedance spectrum shape, suggesting that identification is possible. In Part II, we present a sensitivity analysis of the results to input parameter variability that reveals strengths and limitations of the method, as well as describing possible interactions between input parameters and concurrent degradation modes.

Modeling the Diagnostic Criteria for Alcohol Dependence with Genetic Animal Models

PubMed Central

Kendler, Kenneth S.; Hitzemann, Robert J.

2012-01-01

A diagnosis of alcohol dependence (AD) using the DSM-IV-R is categorical, based on an individual’s manifestation of three or more symptoms from a list of seven. AD risk can be traced to both genetic and environmental sources. Most genetic studies of AD risk implicitly assume that an AD diagnosis represents a single underlying genetic factor. We recently found that the criteria for an AD diagnosis represent three somewhat distinct genetic paths to individual risk. Specifically, heavy use and tolerance versus withdrawal and continued use despite problems reflected separate genetic factors. However, some data suggest that genetic risk for AD is adequately described with a single underlying genetic risk factor. Rodent animal models for alcohol-related phenotypes typically target discrete aspects of the complex human AD diagnosis. Here, we review the literature derived from genetic animal models in an attempt to determine whether they support a single-factor or multiple-factor genetic structure. We conclude that there is modest support in the animal literature that alcohol tolerance and withdrawal reflect distinct genetic risk factors, in agreement with our human data. We suggest areas where more research could clarify this attempt to align the rodent and human data. PMID:21910077

Using Transom Jack in the Human Engineering Analysis of the Materials Science Research Rack-1 and Quench Module Insert

NASA Technical Reports Server (NTRS)

Dunn, Mariea C.; Alves, Jeffrey R.; Hutchinson, Sonya L.

1999-01-01

This paper describes the human engineering analysis performed on the Materials Science Research Rack-1 and Quench Module Insert (MSRR-1/QMI) using Transom Jack (Jack) software. The Jack software was used to model a virtual environment consisting of the MSRR-1/QMI hardware configuration and human figures representing the 95th percentile male and 5th percentile female. The purpose of the simulation was to assess the human interfaces in the design for their ability to meet the requirements of the Pressurized Payloads Interface Requirements Document - International Space Program, Revision C (SSP 57000). Jack was used in the evaluation because of its ability to correctly model anthropometric body measurements and the physical behavior of astronauts working in microgravity, which is referred to as the neutral body posture. The Jack model allows evaluation of crewmember interaction with hardware through task simulation including but not limited to collision avoidance behaviors, hand/eye coordination, reach path planning, and automatic grasping to part contours. Specifically, this virtual simulation depicts the human figures performing the QMI installation and check-out, sample cartridge insertion and removal, and gas bottle drawer removal. These tasks were evaluated in terms of adequate clearance in reach envelopes, adequate accessibility in work envelopes, appropriate line of sight in visual envelopes, and accommodation of full size range for male and female stature maneuverability. The results of the human engineering analysis virtual simulation indicate that most of the associated requirements of SSP 57000 were met. However, some hardware design considerations and crew procedures modifications are recommended to improve accessibility, provide an adequate work envelope, reduce awkward body posture, and eliminate permanent protrusions.

ELECTROFISHING DISTANCE AND NUMBER OF SPECIES COLLECTED FROM THREE RAFTABLE WESTERN RIVERS

EPA Science Inventory

A key issue in assessing a fish assemblage at a site is determining a sufficient sampling effort to adequately represent the species in an assemblage. Inadequate effort produces considerable noise in multiple samples at the site or under-represents the species present. Excessiv...

77 FR 9210 - International Pacific Halibut Commission Appointments

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-16

... duties, Commissioners represent the interests of the United States and all of its stakeholders in the... Pacific Halibut Commission (IPHC). This action is necessary to ensure that the interests of the United States and all of its stakeholders in the Pacific halibut fishery are adequately represented. The...

Can we adequately represent the spatial interplay between humans and nature?

EPA Science Inventory

One of the challenges remaining before ecosystem services assessments can become part of mainstream decision making is how to spatially represent the interplay of nature as a whole and humans. Nature’s ecosystems act as natural capital by producing things (i.e. stocks and ...

Continuum-level modelling of cellular adhesion and matrix production in aggregates.

PubMed

Geris, Liesbet; Ashbourn, Joanna M A; Clarke, Tim

2011-05-01

Key regulators in tissue-engineering processes such as cell culture and cellular organisation are the cell-cell and cell-matrix interactions. As mathematical models are increasingly applied to investigate biological phenomena in the biomedical field, it is important, for some applications, that these models incorporate an adequate description of cell adhesion. This study describes the development of a continuum model that represents a cell-in-gel culture system used in bone-tissue engineering, namely that of a cell aggregate embedded in a hydrogel. Cell adhesion is modelled through the use of non-local (integral) terms in the partial differential equations. The simulation results demonstrate that the effects of cell-cell and cell-matrix adhesion are particularly important for the survival and growth of the cell population and the production of extracellular matrix by the cells, concurring with experimental observations in the literature.

On the multi-scale description of micro-structured fluids composed of aggregating rods

NASA Astrophysics Data System (ADS)

Perez, Marta; Scheuer, Adrien; Abisset-Chavanne, Emmanuelle; Ammar, Amine; Chinesta, Francisco; Keunings, Roland

2018-05-01

When addressing the flow of concentrated suspensions composed of rods, dense clusters are observed. Thus, the adequate modelling and simulation of such a flow requires addressing the kinematics of these dense clusters and their impact on the flow in which they are immersed. In a former work, we addressed a first modelling framework of these clusters, assumed so dense that they were considered rigid and their kinematics (flow-induced rotation) were totally defined by a symmetric tensor c with unit trace representing the cluster conformation. Then, the rigid nature of the clusters was relaxed, assuming them deformable, and a model giving the evolution of both the cluster shape and its microstructural orientation descriptor (the so-called shape and orientation tensors) was proposed. This paper compares the predictions coming from those models with finer-scale discrete simulations inspired from molecular dynamics modelling.

The effects of missing data on global ozone estimates

NASA Technical Reports Server (NTRS)

Drewry, J. W.; Robbins, J. L.

1981-01-01

The effects of missing data and model truncation on estimates of the global mean, zonal distribution, and global distribution of ozone are considered. It is shown that missing data can introduce biased estimates with errors that are not accounted for in the accuracy calculations of empirical modeling techniques. Data-fill techniques are introduced and used for evaluating error bounds and constraining the estimate in areas of sparse and missing data. It is found that the accuracy of the global mean estimate is more dependent on data distribution than model size. Zonal features can be accurately described by 7th order models over regions of adequate data distribution. Data variance accounted for by higher order models appears to represent climatological features of columnar ozone rather than pure error. Data-fill techniques can prevent artificial feature generation in regions of sparse or missing data without degrading high order estimates over dense data regions.

Development of Design Standards and Guidelines for Electromagnetic Compatibility and Lightning Protection for Spacecraft Utilizing Composite Materials

NASA Technical Reports Server (NTRS)

1996-01-01

Preliminary design guidelines necessary to assure electromagnetic compatibility (EMC) of spacecraft using composite materials, are presented. A database of electrical properties of composite materials which may have an effect on EMC is established. The guidelines concentrate on the composites that are conductive but may require enhancement to be adequate for EMC purposes. These composites are represented by graphite reinforced polymers. Methods for determining adequate conductivity levels for various EMC purposes are defined, along with the methods of design which increase conductivity of composite materials and joints to adequate levels.

Fronts and precipitation in CMIP5 models for the austral winter of the Southern Hemisphere

NASA Astrophysics Data System (ADS)

Blázquez, Josefina; Solman, Silvina A.

2018-04-01

Wintertime fronts climatology and the relationship between fronts and precipitation as depicted by a group of CMIP5 models are evaluated over the Southern Hemisphere (SH). The frontal activity is represented by an index that takes into account the vorticity, the gradient of temperature and the specific humidity at the 850 hPa level. ERA-Interim reanalysis and GPCP datasets are used to assess the performance of the models in the present climate. Overall, it is found that the models can reproduce adequately the main features of frontal activity and front frequency over the SH. The total precipitation is overestimated in most of the models, especially the maximum values over the mid latitudes. This overestimation could be related to the high values of precipitation frequency that are identified in some of the models evaluated. The relationship between fronts and precipitation has also been evaluated in terms of both frequency of frontal precipitation and percentage of precipitation due to fronts. In general terms, the models overestimate the proportion between frontal and total precipitation. In contrast with frequency of total precipitation, the frequency of frontal precipitation is well reproduced by the models, with the higher values located at the mid latitudes. The results suggest that models represent very well the dynamic forcing (fronts) and the frequency of frontal precipitation, though the amount of precipitation due to fronts is overestimated.

Comparison of CEAS and Williams-type models for spring wheat yields in North Dakota and Minnesota

NASA Technical Reports Server (NTRS)

Barnett, T. L. (Principal Investigator)

1982-01-01

The CEAS and Williams-type yield models are both based on multiple regression analysis of historical time series data at CRD level. The CEAS model develops a separate relation for each CRD; the Williams-type model pools CRD data to regional level (groups of similar CRDs). Basic variables considered in the analyses are USDA yield, monthly mean temperature, monthly precipitation, and variables derived from these. The Williams-type model also used soil texture and topographic information. Technological trend is represented in both by piecewise linear functions of year. Indicators of yield reliability obtained from a ten-year bootstrap test of each model (1970-1979) demonstrate that the models are very similar in performance in all respects. Both models are about equally objective, adequate, timely, simple, and inexpensive. Both consider scientific knowledge on a broad scale but not in detail. Neither provides a good current measure of modeled yield reliability. The CEAS model is considered very slightly preferable for AgRISTARS applications.

Evaluation of Ciprofloxacin as a Representative of Veterinary Fluoroquinolones in Susceptibility Testing

PubMed Central

Riddle, Christa; Lemons, Carol L.; Papich, Mark G.; Altier, Craig

2000-01-01

Currently in veterinary medicine, ciprofloxacin is often used in susceptibility testing to represent the entire class of fluoroquinolone antimicrobials. Using quality control organisms as well as clinical isolates, we compared the MIC of ciprofloxacin to those of three other fluoroquinolones used in animals and found that ciprofloxacin is not an adequate representative of other members of this class. PMID:10747156

Representative Agricultural Pathways and Scenarios for Regional Integrated Assessment of Climate Change Impacts, Vulnerability, and Adaptation. 5; Chapter

NASA Technical Reports Server (NTRS)

Valdivia, Roberto O.; Antle, John M.; Rosenzweig, Cynthia; Ruane, Alexander C.; Vervoort, Joost; Ashfaq, Muhammad; Hathie, Ibrahima; Tui, Sabine Homann-Kee; Mulwa, Richard; Nhemachena, Charles;

Coupled rotor/airframe vibration analysis

NASA Technical Reports Server (NTRS)

Sopher, R.; Studwell, R. E.; Cassarino, S.; Kottapalli, S. B. R.

1982-01-01

A coupled rotor/airframe vibration analysis developed as a design tool for predicting helicopter vibrations and a research tool to quantify the effects of structural properties, aerodynamic interactions, and vibration reduction devices on vehicle vibration levels is described. The analysis consists of a base program utilizing an impedance matching technique to represent the coupled rotor/airframe dynamics of the system supported by inputs from several external programs supplying sophisticated rotor and airframe aerodynamic and structural dynamic representation. The theoretical background, computer program capabilities and limited correlation results are presented in this report. Correlation results using scale model wind tunnel results show that the analysis can adequately predict trends of vibration variations with airspeed and higher harmonic control effects. Predictions of absolute values of vibration levels were found to be very sensitive to modal characteristics and results were not representative of measured values.

Evaluation of LOINC for Representing Constitutional Cytogenetic Test Result Reports

PubMed Central

Heras, Yan Z.; Mitchell, Joyce A.; Williams, Marc S.; Brothman, Arthur R.; Huff, Stanley M.

2009-01-01

Genetic testing is becoming increasingly important to medical practice. Integrating genetics and genomics data into electronic medical records is crucial in translating genetic discoveries into improved patient care. Information technology, especially Clinical Decision Support Systems, holds great potential to help clinical professionals take full advantage of genomic advances in their daily medical practice. However, issues relating to standard terminology and information models for exchanging genetic testing results remain relatively unexplored. This study evaluates whether the current LOINC standard is adequate to represent constitutional cytogenetic test result reports using sample result reports from ARUP Laboratories. The results demonstrate that current standard terminology is insufficient to support the needs of coding cytogenetic test results. The terminology infrastructure must be developed before clinical information systems will be able to handle the high volumes of genetic data expected in the near future. PMID:20351857

Evaluation of LOINC for representing constitutional cytogenetic test result reports.

PubMed

Heras, Yan Z; Mitchell, Joyce A; Williams, Marc S; Brothman, Arthur R; Huff, Stanley M

2009-11-14

Genetic testing is becoming increasingly important to medical practice. Integrating genetics and genomics data into electronic medical records is crucial in translating genetic discoveries into improved patient care. Information technology, especially Clinical Decision Support Systems, holds great potential to help clinical professionals take full advantage of genomic advances in their daily medical practice. However, issues relating to standard terminology and information models for exchanging genetic testing results remain relatively unexplored. This study evaluates whether the current LOINC standard is adequate to represent constitutional cytogenetic test result reports using sample result reports from ARUP Laboratories. The results demonstrate that current standard terminology is insufficient to support the needs of coding cytogenetic test results. The terminology infrastructure must be developed before clinical information systems will be able to handle the high volumes of genetic data expected in the near future.

Solar Power Satellite (SPS) solid-state antenna power combiner

NASA Technical Reports Server (NTRS)

1980-01-01

A low loss power-combining microstrip antenna suitable for solid state solar power satellite (SPS) application was developed. A unique approach for performing both the combining and radiating function in a single cavity-type circuit was verified, representing substantial refinements over previous demonstration models in terms of detailed geometry to obtain good matching and adequate bandwidth at the design frequency. The combiner circuit was designed, built, and tested and the overall results support the view that the solid state power-combining antenna approach is a viable candidate for a solid state SPS antenna building block.

Low-dimensional chaos in magnetospheric activity from AE time series

NASA Technical Reports Server (NTRS)

Vassiliadis, D. V.; Sharma, A. S.; Eastman, T. E.; Papadopoulos, K.

1990-01-01

The magnetospheric response to the solar-wind input, as represented by the time-series measurements of the auroral electrojet (AE) index, has been examined using phase-space reconstruction techniques. The system was found to behave as a low-dimensional chaotic system with a fractal dimension of 3.6 and has Kolmogorov entropy less than 0.2/min. These indicate that the dynamics of the system can be adequately described by four independent variables, and that the corresponding intrinsic time scale is of the order of 5 min. The relevance of the results to magnetospheric modeling is discussed.

The global carbon dioxide budget

USGS Publications Warehouse

Sundquist, E.T.

1993-01-01

The increase in atmospheric CO2 levels during the last deglaciation was comparable in magnitude to the recent historical increase. However, global CO2 budgets for these changes reflect fundamental differences in rates and in sources and sinks. The modern oceans are a rapid net CO2 sink, whereas the oceans were a gradual source during the deglaciation. Unidentified terrestrial CO2 sinks are important uncertainties in both the deglacial and recent CO2 budgets. The deglacial CO2 budget represents a complexity of long-term dynamic behavior that is not adequately addressed by current models used to forecast future atmospheric CO2 levels.

Model-Driven Approach for Body Area Network Application Development.

PubMed

Venčkauskas, Algimantas; Štuikys, Vytautas; Jusas, Nerijus; Burbaitė, Renata

2016-05-12

This paper introduces the sensor-networked IoT model as a prototype to support the design of Body Area Network (BAN) applications for healthcare. Using the model, we analyze the synergistic effect of the functional requirements (data collection from the human body and transferring it to the top level) and non-functional requirements (trade-offs between energy-security-environmental factors, treated as Quality-of-Service (QoS)). We use feature models to represent the requirements at the earliest stage for the analysis and describe a model-driven methodology to design the possible BAN applications. Firstly, we specify the requirements as the problem domain (PD) variability model for the BAN applications. Next, we introduce the generative technology (meta-programming as the solution domain (SD)) and the mapping procedure to map the PD feature-based variability model onto the SD feature model. Finally, we create an executable meta-specification that represents the BAN functionality to describe the variability of the problem domain though transformations. The meta-specification (along with the meta-language processor) is a software generator for multiple BAN-oriented applications. We validate the methodology with experiments and a case study to generate a family of programs for the BAN sensor controllers. This enables to obtain the adequate measure of QoS efficiently through the interactive adjustment of the meta-parameter values and re-generation process for the concrete BAN application.

Model-Driven Approach for Body Area Network Application Development

PubMed Central

Venčkauskas, Algimantas; Štuikys, Vytautas; Jusas, Nerijus; Burbaitė, Renata

2016-01-01

This paper introduces the sensor-networked IoT model as a prototype to support the design of Body Area Network (BAN) applications for healthcare. Using the model, we analyze the synergistic effect of the functional requirements (data collection from the human body and transferring it to the top level) and non-functional requirements (trade-offs between energy-security-environmental factors, treated as Quality-of-Service (QoS)). We use feature models to represent the requirements at the earliest stage for the analysis and describe a model-driven methodology to design the possible BAN applications. Firstly, we specify the requirements as the problem domain (PD) variability model for the BAN applications. Next, we introduce the generative technology (meta-programming as the solution domain (SD)) and the mapping procedure to map the PD feature-based variability model onto the SD feature model. Finally, we create an executable meta-specification that represents the BAN functionality to describe the variability of the problem domain though transformations. The meta-specification (along with the meta-language processor) is a software generator for multiple BAN-oriented applications. We validate the methodology with experiments and a case study to generate a family of programs for the BAN sensor controllers. This enables to obtain the adequate measure of QoS efficiently through the interactive adjustment of the meta-parameter values and re-generation process for the concrete BAN application. PMID:27187394

Probabilistic description of ice-supersaturated layers in low resolution profiles of relative humidity

NASA Astrophysics Data System (ADS)

Dickson, N. C.; Gierens, K. M.; Rogers, H. L.; Jones, R. L.

2010-07-01

The global observation, assimilation and prediction in numerical models of ice super-saturated (ISS) regions (ISSR) are crucial if the climate impact of aircraft condensation trails (contrails) is to be fully understood, and if, for example, contrail formation is to be avoided through aircraft operational measures. Given their small scales compared to typical atmospheric model grid sizes, statistical representations of the spatial scales of ISSR are required, in both horizontal and vertical dimensions, if global occurrence of ISSR is to be adequately represented in climate models. This paper uses radiosonde launches made by the UK Meteorological Office, from the British Isles, Gibraltar, St. Helena and the Falkland Islands between January 2002 and December 2006, to investigate the probabilistic occurrence of ISSR. Each radiosonde profile is divided into 50- and 100-hPa pressure layers, to emulate the coarse vertical resolution of some atmospheric models. Then the high resolution observations contained within each thick pressure layer are used to calculate an average relative humidity and an ISS fraction for each individual thick pressure layer. These relative humidity pressure layer descriptions are then linked through a probability function to produce an s-shaped curve which empirically describes the ISS fraction in any average relative humidity pressure layer. Using this empirical understanding of the s-shaped relationship a mathematical model was developed to represent the ISS fraction within any arbitrary thick pressure layer. Two models were developed to represent both 50- and 100-hPa pressure layers with each reconstructing their respective s-shapes within 8-10% of the empirical curves. These new models can be used, to represent the small scale structures of ISS events, in modelled data where only low vertical resolution is available. This will be useful in understanding, and improving the global distribution, both observed and forecasted, of ice super-saturation.

Multiscale solute transport upscaling for a three-dimensional hierarchical porous medium

NASA Astrophysics Data System (ADS)

Zhang, Mingkan; Zhang, Ye

2015-03-01

A laboratory-generated hierarchical, fully heterogeneous aquifer model (FHM) provides a reference for developing and testing an upscaling approach that integrates large-scale connectivity mapping with flow and transport modeling. Based on the FHM, three hydrostratigraphic models (HSMs) that capture lithological (static) connectivity at different resolutions are created, each corresponding to a sedimentary hierarchy. Under increasing system lnK variances (0.1, 1.0, 4.5), flow upscaling is first conducted to calculate equivalent hydraulic conductivity for individual connectivity (or unit) of the HSMs. Given the computed flow fields, an instantaneous, conservative tracer test is simulated by all models. For the HSMs, two upscaling formulations are tested based on the advection-dispersion equation (ADE), implementing space versus time-dependent macrodispersivity. Comparing flow and transport predictions of the HSMs against those of the reference model, HSMs capturing connectivity at increasing resolutions are more accurate, although upscaling errors increase with system variance. Results suggest: (1) by explicitly modeling connectivity, an enhanced degree of freedom in representing dispersion can improve the ADE-based upscaled models by capturing non-Fickian transport of the FHM; (2) when connectivity is sufficiently resolved, the type of data conditioning used to model transport becomes less critical. Data conditioning, however, is influenced by the prediction goal; (3) when aquifer is weakly-to-moderately heterogeneous, the upscaled models adequately capture the transport simulation of the FHM, despite the existence of hierarchical heterogeneity at smaller scales. When aquifer is strongly heterogeneous, the upscaled models become less accurate because lithological connectivity cannot adequately capture preferential flows; (4) three-dimensional transport connectivities of the hierarchical aquifer differ quantitatively from those analyzed for two-dimensional systems. This article was corrected on 7 MAY 2015. See the end of the full text for details.

Application of Non-Deterministic Methods to Assess Modeling Uncertainties for Reinforced Carbon-Carbon Debris Impacts

NASA Technical Reports Server (NTRS)

Lyle, Karen H.; Fasanella, Edwin L.; Melis, Matthew; Carney, Kelly; Gabrys, Jonathan

2004-01-01

The Space Shuttle Columbia Accident Investigation Board (CAIB) made several recommendations for improving the NASA Space Shuttle Program. An extensive experimental and analytical program has been developed to address two recommendations related to structural impact analysis. The objective of the present work is to demonstrate the application of probabilistic analysis to assess the effect of uncertainties on debris impacts on Space Shuttle Reinforced Carbon-Carbon (RCC) panels. The probabilistic analysis is used to identify the material modeling parameters controlling the uncertainty. A comparison of the finite element results with limited experimental data provided confidence that the simulations were adequately representing the global response of the material. Five input parameters were identified as significantly controlling the response.

Hierarchical mixture of experts and diagnostic modeling approach to reduce hydrologic model structural uncertainty: STRUCTURAL UNCERTAINTY DIAGNOSTICS

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

Moges, Edom; Demissie, Yonas; Li, Hong-Yi

2016-04-01

In most water resources applications, a single model structure might be inadequate to capture the dynamic multi-scale interactions among different hydrological processes. Calibrating single models for dynamic catchments, where multiple dominant processes exist, can result in displacement of errors from structure to parameters, which in turn leads to over-correction and biased predictions. An alternative to a single model structure is to develop local expert structures that are effective in representing the dominant components of the hydrologic process and adaptively integrate them based on an indicator variable. In this study, the Hierarchical Mixture of Experts (HME) framework is applied to integratemore » expert model structures representing the different components of the hydrologic process. Various signature diagnostic analyses are used to assess the presence of multiple dominant processes and the adequacy of a single model, as well as to identify the structures of the expert models. The approaches are applied for two distinct catchments, the Guadalupe River (Texas) and the French Broad River (North Carolina) from the Model Parameter Estimation Experiment (MOPEX), using different structures of the HBV model. The results show that the HME approach has a better performance over the single model for the Guadalupe catchment, where multiple dominant processes are witnessed through diagnostic measures. Whereas, the diagnostics and aggregated performance measures prove that French Broad has a homogeneous catchment response, making the single model adequate to capture the response.« less

First "glass" education: telementored cardiac ultrasonography using Google Glass- a pilot study.

PubMed

Russell, Patrick M; Mallin, Michael; Youngquist, Scott T; Cotton, Jennifer; Aboul-Hosn, Nael; Dawson, Matt

2014-11-01

The objective of this study was to determine the feasibility of telementored instruction in bedside ultrasonography (US) using Google Glass. The authors sought to examine whether first-time US users could obtain adequate parasternal long axis (PSLA) views to approximate ejection fraction (EF) using Google Glass telementoring. This was a prospective, randomized, single-blinded study. Eighteen second-year medical students were randomized into three groups and tasked with obtaining PSLA cardiac imaging. Group A received real-time telementored education through Google Glass via Google Hangout from a remotely located expert. Group B received bedside education from the same expert. Group C represented the control and received no instruction. Each subject was given 3 minutes to obtain a best PSLA cardiac imaging using a portable GE Vscan. Image clips obtained by each subject were stored. A second expert, blinded to instructional mode, evaluated images for adequacy and assigned an image quality rating on a 0 to 10 scale. Group A was able to obtain adequate images six out of six times (100%) with a median image quality rating of 7.5 (interquartile range [IQR] = 6 to 10) out of 10. Group B was also able to obtain adequate views six out of six times (100%), with a median image quality rating of 8 (IQR = 7 to 9). Group C was able to obtain adequate views one out of six times (17%), with a median image quality of 0 (IQR = 0 to 2). There were no statistically significant differences between Group A and Group B in the achievement of adequate images for E-point septal separation measurement or in image quality. In this pilot/feasibility study, novice US users were able to obtain adequate imaging to determine a healthy patient's EF through telementored education using Google Glass. These preliminary data suggest telementoring as an adequate means of medical education in bedside US. This conclusion will need to be validated with larger, more powerful studies including evaluation of pathologic findings and varying body habitus among models. © 2014 by the Society for Academic Emergency Medicine.

A Human Pluripotent Stem Cell Model of Facioscapulohumeral Muscular Dystrophy-Affected Skeletal Muscles.

PubMed

Caron, Leslie; Kher, Devaki; Lee, Kian Leong; McKernan, Robert; Dumevska, Biljana; Hidalgo, Alejandro; Li, Jia; Yang, Henry; Main, Heather; Ferri, Giulia; Petek, Lisa M; Poellinger, Lorenz; Miller, Daniel G; Gabellini, Davide; Schmidt, Uli

2016-09-01

: Facioscapulohumeral muscular dystrophy (FSHD) represents a major unmet clinical need arising from the progressive weakness and atrophy of skeletal muscles. The dearth of adequate experimental models has severely hampered our understanding of the disease. To date, no treatment is available for FSHD. Human embryonic stem cells (hESCs) potentially represent a renewable source of skeletal muscle cells (SkMCs) and provide an alternative to invasive patient biopsies. We developed a scalable monolayer system to differentiate hESCs into mature SkMCs within 26 days, without cell sorting or genetic manipulation. Here we show that SkMCs derived from FSHD1-affected hESC lines exclusively express the FSHD pathogenic marker double homeobox 4 and exhibit some of the defects reported in FSHD. FSHD1 myotubes are thinner when compared with unaffected and Becker muscular dystrophy myotubes, and differentially regulate genes involved in cell cycle control, oxidative stress response, and cell adhesion. This cellular model will be a powerful tool for studying FSHD and will ultimately assist in the development of effective treatments for muscular dystrophies. This work describes an efficient and highly scalable monolayer system to differentiate human pluripotent stem cells (hPSCs) into skeletal muscle cells (SkMCs) and demonstrates disease-specific phenotypes in SkMCs derived from both embryonic and induced hPSCs affected with facioscapulohumeral muscular dystrophy. This study represents the first human stem cell-based cellular model for a muscular dystrophy that is suitable for high-throughput screening and drug development. ©AlphaMed Press.

Source-term development for a contaminant plume for use by multimedia risk assessment models

NASA Astrophysics Data System (ADS)

Whelan, Gene; McDonald, John P.; Taira, Randal Y.; Gnanapragasam, Emmanuel K.; Yu, Charley; Lew, Christine S.; Mills, William B.

2000-02-01

Multimedia modelers from the US Environmental Protection Agency (EPA) and US Department of Energy (DOE) are collaborating to conduct a comprehensive and quantitative benchmarking analysis of four intermedia models: MEPAS, MMSOILS, PRESTO, and RESRAD. These models represent typical analytically based tools that are used in human-risk and endangerment assessments at installations containing radioactive and hazardous contaminants. The objective is to demonstrate an approach for developing an adequate source term by simplifying an existing, real-world, 90Sr plume at DOE's Hanford installation in Richland, WA, for use in a multimedia benchmarking exercise between MEPAS, MMSOILS, PRESTO, and RESRAD. Source characteristics and a release mechanism are developed and described; also described is a typical process and procedure that an analyst would follow in developing a source term for using this class of analytical tool in a preliminary assessment.

From Near-Neutral to Strongly Stratified: Adequately Modelling the Clear-Sky Nocturnal Boundary Layer at Cabauw.

PubMed

Baas, P; van de Wiel, B J H; van der Linden, S J A; Bosveld, F C

2018-01-01

The performance of an atmospheric single-column model (SCM) is studied systematically for stably-stratified conditions. To this end, 11 years (2005-2015) of daily SCM simulations were compared to observations from the Cabauw observatory, The Netherlands. Each individual clear-sky night was classified in terms of the ambient geostrophic wind speed with a [Formula: see text] bin-width. Nights with overcast conditions were filtered out by selecting only those nights with an average net radiation of less than [Formula: see text]. A similar procedure was applied to the observational dataset. A comparison of observed and modelled ensemble-averaged profiles of wind speed and potential temperature and time series of turbulent fluxes showed that the model represents the dynamics of the nocturnal boundary layer (NBL) at Cabauw very well for a broad range of mechanical forcing conditions. No obvious difference in model performance was found between near-neutral and strongly-stratified conditions. Furthermore, observed NBL regime transitions are represented in a natural way. The reference model version performs much better than a model version that applies excessive vertical mixing as is done in several (global) operational models. Model sensitivity runs showed that for weak-wind conditions the inversion strength depends much more on details of the land-atmosphere coupling than on the turbulent mixing. The presented results indicate that in principle the physical parametrizations of large-scale atmospheric models are sufficiently equipped for modelling stably-stratified conditions for a wide range of forcing conditions.

From Near-Neutral to Strongly Stratified: Adequately Modelling the Clear-Sky Nocturnal Boundary Layer at Cabauw

NASA Astrophysics Data System (ADS)

Baas, P.; van de Wiel, B. J. H.; van der Linden, S. J. A.; Bosveld, F. C.

2018-02-01

The performance of an atmospheric single-column model (SCM) is studied systematically for stably-stratified conditions. To this end, 11 years (2005-2015) of daily SCM simulations were compared to observations from the Cabauw observatory, The Netherlands. Each individual clear-sky night was classified in terms of the ambient geostrophic wind speed with a 1 m s^{-1} bin-width. Nights with overcast conditions were filtered out by selecting only those nights with an average net radiation of less than - 30 W m^{-2}. A similar procedure was applied to the observational dataset. A comparison of observed and modelled ensemble-averaged profiles of wind speed and potential temperature and time series of turbulent fluxes showed that the model represents the dynamics of the nocturnal boundary layer (NBL) at Cabauw very well for a broad range of mechanical forcing conditions. No obvious difference in model performance was found between near-neutral and strongly-stratified conditions. Furthermore, observed NBL regime transitions are represented in a natural way. The reference model version performs much better than a model version that applies excessive vertical mixing as is done in several (global) operational models. Model sensitivity runs showed that for weak-wind conditions the inversion strength depends much more on details of the land-atmosphere coupling than on the turbulent mixing. The presented results indicate that in principle the physical parametrizations of large-scale atmospheric models are sufficiently equipped for modelling stably-stratified conditions for a wide range of forcing conditions.

Ecosystem Model Skill Assessment. Yes We Can!

PubMed

Olsen, Erik; Fay, Gavin; Gaichas, Sarah; Gamble, Robert; Lucey, Sean; Link, Jason S

2016-01-01

Accelerated changes to global ecosystems call for holistic and integrated analyses of past, present and future states under various pressures to adequately understand current and projected future system states. Ecosystem models can inform management of human activities in a complex and changing environment, but are these models reliable? Ensuring that models are reliable for addressing management questions requires evaluating their skill in representing real-world processes and dynamics. Skill has been evaluated for just a limited set of some biophysical models. A range of skill assessment methods have been reviewed but skill assessment of full marine ecosystem models has not yet been attempted. We assessed the skill of the Northeast U.S. (NEUS) Atlantis marine ecosystem model by comparing 10-year model forecasts with observed data. Model forecast performance was compared to that obtained from a 40-year hindcast. Multiple metrics (average absolute error, root mean squared error, modeling efficiency, and Spearman rank correlation), and a suite of time-series (species biomass, fisheries landings, and ecosystem indicators) were used to adequately measure model skill. Overall, the NEUS model performed above average and thus better than expected for the key species that had been the focus of the model tuning. Model forecast skill was comparable to the hindcast skill, showing that model performance does not degenerate in a 10-year forecast mode, an important characteristic for an end-to-end ecosystem model to be useful for strategic management purposes. We identify best-practice approaches for end-to-end ecosystem model skill assessment that would improve both operational use of other ecosystem models and future model development. We show that it is possible to not only assess the skill of a complicated marine ecosystem model, but that it is necessary do so to instill confidence in model results and encourage their use for strategic management. Our methods are applicable to any type of predictive model, and should be considered for use in fields outside ecology (e.g. economics, climate change, and risk assessment).

Quantifying geological uncertainty for flow and transport modeling in multi-modal heterogeneous formations

NASA Astrophysics Data System (ADS)

Feyen, Luc; Caers, Jef

2006-06-01

In this work, we address the problem of characterizing the heterogeneity and uncertainty of hydraulic properties for complex geological settings. Hereby, we distinguish between two scales of heterogeneity, namely the hydrofacies structure and the intrafacies variability of the hydraulic properties. We employ multiple-point geostatistics to characterize the hydrofacies architecture. The multiple-point statistics are borrowed from a training image that is designed to reflect the prior geological conceptualization. The intrafacies variability of the hydraulic properties is represented using conventional two-point correlation methods, more precisely, spatial covariance models under a multi-Gaussian spatial law. We address the different levels and sources of uncertainty in characterizing the subsurface heterogeneity, and explore their effect on groundwater flow and transport predictions. Typically, uncertainty is assessed by way of many images, termed realizations, of a fixed statistical model. However, in many cases, sampling from a fixed stochastic model does not adequately represent the space of uncertainty. It neglects the uncertainty related to the selection of the stochastic model and the estimation of its input parameters. We acknowledge the uncertainty inherent in the definition of the prior conceptual model of aquifer architecture and in the estimation of global statistics, anisotropy, and correlation scales. Spatial bootstrap is used to assess the uncertainty of the unknown statistical parameters. As an illustrative example, we employ a synthetic field that represents a fluvial setting consisting of an interconnected network of channel sands embedded within finer-grained floodplain material. For this highly non-stationary setting we quantify the groundwater flow and transport model prediction uncertainty for various levels of hydrogeological uncertainty. Results indicate the importance of accurately describing the facies geometry, especially for transport predictions.

Uranium nitride as LWR TRISO fuel: Thermodynamic modeling of U-C-N

NASA Astrophysics Data System (ADS)

Besmann, Theodore M.; Shin, Dongwon; Lindemer, Terrence B.

2012-08-01

TRISO coated particle fuel is envisioned as a next generation replacement for current urania pellet fuel in LWR applications. To obtain adequate fissile loading the kernel of the TRISO particle will likely need to be UN instead of UO2. In support of the necessary development effort for this new fuel system, an assessment of phase regions of interest in the U-C-N system was undertaken as the fuel will be prepared by the carbothermic reduction of the oxide followed by nitriding, will be in equilibrium with carbon within the TRISO particle, and will react with minor actinides and fission products. The phase equilibria and thermochemistry of the U-C-N system is reviewed, including nitrogen pressure measurements above various phase fields. Measurements were used to confirm an ideal solution model of UN and UC adequately represents the UC1-xNx phase. Agreement with the data was significantly improved by effectively adjusting the Gibbs free energy of UN by +12 kJ/mol. This also required adjustment of the value for the sesquinitride by +17 kJ/mol to obtain agreement with phase equilibria. The resultant model together with reported values for other phases in the system was used to generate isothermal sections of the U-C-N phase diagram. Nitrogen partial pressures were also computed for regions of interest.

The development of a survey instrument for community health improvement.

PubMed Central

Bazos, D A; Weeks, W B; Fisher, E S; DeBlois, H A; Hamilton, E; Young, M J

2001-01-01

OBJECTIVE: To develop a survey instrument that could be used both to guide and evaluate community health improvement efforts. DATA SOURCES/STUDY SETTING: A randomized telephone survey was administered to a sample of about 250 residents in two communities in Lehigh Valley, Pennsylvania in the fall of 1997. METHODS: The survey instrument was developed by health professionals representing diverse health care organizations. This group worked collaboratively over a period of two years to (1) select a conceptual model of health as a foundation for the survey; (2) review relevant literature to identify indicators that adequately measured the health constructs within the chosen model; (3) develop new indicators where important constructs lacked specific measures; and (4) pilot test the final survey to assess the reliability and validity of the instrument. PRINCIPAL FINDINGS: The Evans and Stoddart Field Model of the Determinants of Health and Well-Being was chosen as the conceptual model within which to develop the survey. The Field Model depicts nine domains important to the origins and production of health and provides a comprehensive framework from which to launch community health improvement efforts. From more than 500 potential indicators we identified 118 survey questions that reflected the multiple determinants of health as conceptualized by this model. Sources from which indicators were selected include the Behavior Risk Factor Surveillance Survey, the National Health Interview Survey, the Consumer Assessment of Health Plans Survey, and the SF-12 Summary Scales. The work group developed 27 new survey questions for constructs for which we could not locate adequate indicators. Twenty-five questions in the final instrument can be compared to nationally published norms or benchmarks. The final instrument was pilot tested in 1997 in two communities. Administration time averaged 22 minutes with a response rate of 66 percent. Reliability of new survey questions was adequate. Face validity was supported by previous findings from qualitative and quantitative studies. CONCLUSIONS: We developed, pilot tested, and validated a survey instrument designed to provide more comprehensive and timely data to communities for community health assessments. This instrument allows communities to identify and measure critical domains of health that have previously not been captured in a single instrument. PMID:11508639

Forest-atmosphere BVOC exchange in diverse and structurally complex canopies: 1-D modeling of a mid-successional forest in northern Michigan

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

Bryan, Alexander M.; Cheng, Susan J.; Ashworth, Kirsti

Foliar emissions of biogenic volatile organic compounds (BVOC)dimportant precursors of tropospheric ozone and secondary organic aerosolsdvary widely by vegetation type. Modeling studies to date typi-cally represent the canopy as a single dominant tree type or a blend of tree types, yet many forests are diverse with trees of varying height. To assess the sensitivity of biogenic emissions to tree height vari-ation, we compare two 1-D canopy model simulations in which BVOC emission potentials are homo-geneous or heterogeneous with canopy depth. The heterogeneous canopy emulates the mid-successional forest at the University of Michigan Biological Station (UMBS). In this case, high-isoprene-emitting fo-liagemore » (e.g., aspen and oak) is constrained to the upper canopy, where higher sunlight availability increases the light-dependent isoprene emission, leading to 34% more isoprene and its oxidation products as compared to the homogeneous simulation. Isoprene declines from aspen mortality are 10% larger when heterogeneity is considered. Overall, our results highlight the importance of adequately representing complexities of forest canopy structure when simulating light-dependent BVOC emissions and chemistry.« less

Template-Based Modeling of Protein-RNA Interactions.

PubMed

Zheng, Jinfang; Kundrotas, Petras J; Vakser, Ilya A; Liu, Shiyong

2016-09-01

Protein-RNA complexes formed by specific recognition between RNA and RNA-binding proteins play an important role in biological processes. More than a thousand of such proteins in human are curated and many novel RNA-binding proteins are to be discovered. Due to limitations of experimental approaches, computational techniques are needed for characterization of protein-RNA interactions. Although much progress has been made, adequate methodologies reliably providing atomic resolution structural details are still lacking. Although protein-RNA free docking approaches proved to be useful, in general, the template-based approaches provide higher quality of predictions. Templates are key to building a high quality model. Sequence/structure relationships were studied based on a representative set of binary protein-RNA complexes from PDB. Several approaches were tested for pairwise target/template alignment. The analysis revealed a transition point between random and correct binding modes. The results showed that structural alignment is better than sequence alignment in identifying good templates, suitable for generating protein-RNA complexes close to the native structure, and outperforms free docking, successfully predicting complexes where the free docking fails, including cases of significant conformational change upon binding. A template-based protein-RNA interaction modeling protocol PRIME was developed and benchmarked on a representative set of complexes.

A new numerical benchmark for variably saturated variable-density flow and transport in porous media

NASA Astrophysics Data System (ADS)

Guevara, Carlos; Graf, Thomas

2016-04-01

In subsurface hydrological systems, spatial and temporal variations in solute concentration and/or temperature may affect fluid density and viscosity. These variations could lead to potentially unstable situations, in which a dense fluid overlies a less dense fluid. These situations could produce instabilities that appear as dense plume fingers migrating downwards counteracted by vertical upwards flow of freshwater (Simmons et al., Transp. Porous Medium, 2002). As a result of unstable variable-density flow, solute transport rates are increased over large distances and times as compared to constant-density flow. The numerical simulation of variable-density flow in saturated and unsaturated media requires corresponding benchmark problems against which a computer model is validated (Diersch and Kolditz, Adv. Water Resour, 2002). Recorded data from a laboratory-scale experiment of variable-density flow and solute transport in saturated and unsaturated porous media (Simmons et al., Transp. Porous Medium, 2002) is used to define a new numerical benchmark. The HydroGeoSphere code (Therrien et al., 2004) coupled with PEST (www.pesthomepage.org) are used to obtain an optimized parameter set capable of adequately representing the data set by Simmons et al., (2002). Fingering in the numerical model is triggered using random hydraulic conductivity fields. Due to the inherent randomness, a large number of simulations were conducted in this study. The optimized benchmark model adequately predicts the plume behavior and the fate of solutes. This benchmark is useful for model verification of variable-density flow problems in saturated and/or unsaturated media.

Quantifying the Spatial Ecology of Wide-Ranging Marine Species in the Gulf of California: Implications for Marine Conservation Planning

PubMed Central

Anadón, José Daniel; D'Agrosa, Caterina; Gondor, Anne; Gerber, Leah R.

2011-01-01

There is growing interest in systematic establishment of marine protected area (MPA) networks and representative conservation sites. This movement toward networks of no-take zones requires that reserves are deliberately and adequately spaced for connectivity. Here, we test the network functionality of an ecoregional assessment configuration of marine conservation areas by evaluating the habitat protection and connectivity offered to wide-ranging fauna in the Gulf of California (GOC, Mexico). We first use expert opinion to identify representative species of wide-ranging fauna of the GOC. These include leopard grouper, hammerhead sharks, California brown pelicans and green sea turtles. Analyzing habitat models with both structural and functional connectivity indexes, our results indicate that the configuration includes large proportions of biologically important habitat for the four species considered (25–40%), particularly, the best quality habitats (46–57%). Our results also show that connectivity levels offered by the conservation area design for these four species may be similar to connectivity levels offered by the entire Gulf of California, thus indicating that connectivity offered by the areas may resemble natural connectivity. The selected focal species comprise different life histories among marine or marine-related vertebrates and are associated with those habitats holding the most biodiversity values (i.e. coastal habitats); our results thus suggest that the proposed configuration may function as a network for connectivity and may adequately represent the marine megafauna in the GOC, including the potential connectivity among habitat patches. This work highlights the range of approaches that can be used to quantify habitat protection and connectivity for wide-ranging marine species in marine reserve networks. PMID:22163013

Quantifying the spatial ecology of wide-ranging marine species in the Gulf of California: implications for marine conservation planning.

PubMed

Anadón, José Daniel; D'Agrosa, Caterina; Gondor, Anne; Gerber, Leah R

2011-01-01

There is growing interest in systematic establishment of marine protected area (MPA) networks and representative conservation sites. This movement toward networks of no-take zones requires that reserves are deliberately and adequately spaced for connectivity. Here, we test the network functionality of an ecoregional assessment configuration of marine conservation areas by evaluating the habitat protection and connectivity offered to wide-ranging fauna in the Gulf of California (GOC, Mexico). We first use expert opinion to identify representative species of wide-ranging fauna of the GOC. These include leopard grouper, hammerhead sharks, California brown pelicans and green sea turtles. Analyzing habitat models with both structural and functional connectivity indexes, our results indicate that the configuration includes large proportions of biologically important habitat for the four species considered (25-40%), particularly, the best quality habitats (46-57%). Our results also show that connectivity levels offered by the conservation area design for these four species may be similar to connectivity levels offered by the entire Gulf of California, thus indicating that connectivity offered by the areas may resemble natural connectivity. The selected focal species comprise different life histories among marine or marine-related vertebrates and are associated with those habitats holding the most biodiversity values (i.e. coastal habitats); our results thus suggest that the proposed configuration may function as a network for connectivity and may adequately represent the marine megafauna in the GOC, including the potential connectivity among habitat patches. This work highlights the range of approaches that can be used to quantify habitat protection and connectivity for wide-ranging marine species in marine reserve networks.

Simulation of the inhibition of microbial sulfate reduction in a two-compartment upflow bioreactor subjected to molybdate injection.

PubMed

de Jesus, E B; de Andrade Lima, L R P

2016-08-01

Souring of oil fields during secondary oil recovery by water injection occurs mainly due to the action of sulfate-reducing bacteria (SRB) adhered to the rock surface in the vicinity of injection wells. Upflow packed-bed bioreactors have been used in petroleum microbiology because of its similarity to the oil field near the injection wells or production. However, these reactors do not realistically describe the regions near the injection wells, which are characterized by the presence of a saturated zone and a void region close to the well. In this study, the hydrodynamics of the two-compartment packing-free/packed-bed pilot bioreactor that mimics an oil reservoir was studied. The packed-free compartment was modeled using a continuous stirred tank model with mass exchange between active and stagnant zones, whereas the packed-bed compartment was modeled using a piston-dispersion-exchange model. The proposed model adequately represents the hydrodynamic of the packed-free/packed-bed bioreactor while the simulations provide important information about the characteristics of the residence time distribution (RTD) curves for different sets of model parameters. Simulations were performed to represent the control of the sulfate-reducing bacteria activity in the bioreactor with the use of molybdate in different scenarios. The simulations show that increased amounts of molybdate cause an effective inhibition of the souring sulfate-reducing bacteria activity.

Investigating low flow process controls, through complex modelling, in a UK chalk catchment

NASA Astrophysics Data System (ADS)

Lubega Musuuza, Jude; Wagener, Thorsten; Coxon, Gemma; Freer, Jim; Woods, Ross; Howden, Nicholas

2017-04-01

The typical streamflow response of Chalk catchments is dominated by groundwater contributions due the high degree of groundwater recharge through preferential flow pathways. The groundwater store attenuates the precipitation signal, which causes a delay between the corresponding high and low extremes in the precipitation and the stream flow signals. Streamflow responses can therefore be quite out of phase with the precipitation input to a Chalk catchment. Therefore characterising such catchment systems, including modelling approaches, clearly need to reproduce these percolation and groundwater dominated pathways to capture these dominant flow pathways. The simulation of low flow conditions for chalk catchments in numerical models is especially difficult due to the complex interactions between various processes that may not be adequately represented or resolved in the models. Periods of low stream flows are particularly important due to competing water uses in the summer, including agriculture and water supply. In this study we apply and evaluate the physically-based Pennstate Integrated Hydrologic Model (PIHM) to the River Kennet, a sub-catchment of the Thames Basin, to demonstrate how the simulations of a chalk catchment are improved by a physically-based system representation. We also use an ensemble of simulations to investigate the sensitivity of various hydrologic signatures (relevant to low flows and droughts) to the different parameters in the model, thereby inferring the levels of control exerted by the processes that the parameters represent.

Coarsening of physics for biogeochemical model in NEMO

NASA Astrophysics Data System (ADS)

Bricaud, Clement; Le Sommer, Julien; Madec, Gurvan; Deshayes, Julie; Chanut, Jerome; Perruche, Coralie

2017-04-01

Ocean mesoscale and submesoscale turbulence contribute to ocean tracer transport and to shaping ocean biogeochemical tracers distribution. Representing adequately tracer transport in ocean models therefore requires to increase model resolution so that the impact of ocean turbulence is adequately accounted for. But due to supercomputers power and storage limitations, global biogeochemical models are not yet run routinely at eddying resolution. Still, because the "effective resolution" of eddying ocean models is much coarser than the physical model grid resolution, tracer transport can be reconstructed to a large extent by computing tracer transport and diffusion with a model grid resolution close to the effective resolution of the physical model. This observation has motivated the implementation of a new capability in NEMO ocean model (http://www.nemo-ocean.eu/) that allows to run the physical model and the tracer transport model at different grid resolutions. In a first time, we present results obtained with this new capability applied to a synthetic age tracer in a global eddying model configuration. In this model configuration, ocean dynamic is computed at ¼° resolution but tracer transport is computed at 3/4° resolution. The solution obtained is compared to 2 reference setup ,one at ¼° resolution for both physics and passive tracer models and one at 3/4° resolution for both physics and passive tracer model. We discuss possible options for defining the vertical diffusivity coefficient for the tracer transport model based on information from the high resolution grid. We describe the impact of this choice on the distribution and one the penetration of the age tracer. In a second time we present results obtained by coupling the physics with the biogeochemical model PISCES. We look at the impact of this methodology on some tracers distribution and dynamic. The method described here can found applications in ocean forecasting, such as the Copernicus Marine service operated by Mercator-Ocean, and in Earth System Models for climate applications.

Multiscale dispersion-state characterization of nanocomposites using optical coherence tomography

PubMed Central

Schneider, Simon; Eppler, Florian; Weber, Marco; Olowojoba, Ganiu; Weiss, Patrick; Hübner, Christof; Mikonsaari, Irma; Freude, Wolfgang; Koos, Christian

2016-01-01

Nanocomposite materials represent a success story of nanotechnology. However, development of nanomaterial fabrication still suffers from the lack of adequate analysis tools. In particular, achieving and maintaining well-dispersed particle distributions is a key challenge, both in material development and industrial production. Conventional methods like optical or electron microscopy need laborious, costly sample preparation and do not permit fast extraction of nanoscale structural information from statistically relevant sample volumes. Here we show that optical coherence tomography (OCT) represents a versatile tool for nanomaterial characterization, both in a laboratory and in a production environment. The technique does not require sample preparation and is applicable to a wide range of solid and liquid material systems. Large particle agglomerates can be directly found by OCT imaging, whereas dispersed nanoparticles are detected by model-based analysis of depth-dependent backscattering. Using a model system of polystyrene nanoparticles, we demonstrate nanoparticle sizing with high accuracy. We further prove the viability of the approach by characterizing highly relevant material systems based on nanoclays or carbon nanotubes. The technique is perfectly suited for in-line metrology in a production environment, which is demonstrated using a state-of-the-art compounding extruder. These experiments represent the first demonstration of multiscale nanomaterial characterization using OCT. PMID:27557544

Multiscale dispersion-state characterization of nanocomposites using optical coherence tomography.

PubMed

Schneider, Simon; Eppler, Florian; Weber, Marco; Olowojoba, Ganiu; Weiss, Patrick; Hübner, Christof; Mikonsaari, Irma; Freude, Wolfgang; Koos, Christian

2016-08-25

Nanocomposite materials represent a success story of nanotechnology. However, development of nanomaterial fabrication still suffers from the lack of adequate analysis tools. In particular, achieving and maintaining well-dispersed particle distributions is a key challenge, both in material development and industrial production. Conventional methods like optical or electron microscopy need laborious, costly sample preparation and do not permit fast extraction of nanoscale structural information from statistically relevant sample volumes. Here we show that optical coherence tomography (OCT) represents a versatile tool for nanomaterial characterization, both in a laboratory and in a production environment. The technique does not require sample preparation and is applicable to a wide range of solid and liquid material systems. Large particle agglomerates can be directly found by OCT imaging, whereas dispersed nanoparticles are detected by model-based analysis of depth-dependent backscattering. Using a model system of polystyrene nanoparticles, we demonstrate nanoparticle sizing with high accuracy. We further prove the viability of the approach by characterizing highly relevant material systems based on nanoclays or carbon nanotubes. The technique is perfectly suited for in-line metrology in a production environment, which is demonstrated using a state-of-the-art compounding extruder. These experiments represent the first demonstration of multiscale nanomaterial characterization using OCT.

Psychometric properties and measurement invariance of the Beck hopelessness scale (BHS): results from a German representative population sample.

PubMed

Kliem, Sören; Lohmann, Anna; Mößle, Thomas; Brähler, Elmar

2018-04-25

The Beck Hopelessness Scale (BHS) has been the most frequently used instrument for the measurement of hopelessness in the past 40 years. Only recently has it officially been translated into German. The psychometric properties and factor structure of the BHS have been cause for intensive debate in the past. Based on a representative sample of the German population (N = 2450) item analysis including item sensitivity, item-total correlation and item difficulty was performed. Confirmatory factor analyses (CFA) for several factor solutions from the literature were performed. Multiple group factor analysis was performed to assess measurement invariance. Construct validity was assessed via the replication of well-established correlations with concurrently assessed measures. Most items exhibited adequate properties. Items #4, #8 and #13 exhibited poor item characteristics- each of these items had previously received negative evaluations in international studies. A one-dimensional factor solution, favorable for the calculation and interpretation of a sum score, was regarded as adequate. A bi-factor model with one content factor and two method factors (defined by positive/negative item coding) resulted in an excellent model fit. Cronbach's alpha in the current sample was .87. Hopelessness, as measured by the BHS, significantly correlated in the expected direction with suicidal ideation (r = .36), depression (r = .53) and life satisfaction (r = -.53). Strict measurement invariance could be established regarding gender and depression status. Due to limited research regarding the interpretation of fit indices with dichotomous data, interpretation of CFA results needs to remain tentative. The BHS is a valid measure of hopelessness in various subgroups of the general population. Future research could aim at replicating these findings using item response theory and cross-cultural samples. A one-dimensional bi-factor model seems appropriate even in a non-clinical population.

Optimum Design of a Helicopter Rotor for Low Vibration Using Aeroelastic Analysis and Response Surface Methods

NASA Astrophysics Data System (ADS)

Ganguli, R.

2002-11-01

An aeroelastic analysis based on finite elements in space and time is used to model the helicopter rotor in forward flight. The rotor blade is represented as an elastic cantilever beam undergoing flap and lag bending, elastic torsion and axial deformations. The objective of the improved design is to reduce vibratory loads at the rotor hub that are the main source of helicopter vibration. Constraints are imposed on aeroelastic stability, and move limits are imposed on the blade elastic stiffness design variables. Using the aeroelastic analysis, response surface approximations are constructed for the objective function (vibratory hub loads). It is found that second order polynomial response surfaces constructed using the central composite design of the theory of design of experiments adequately represents the aeroelastic model in the vicinity of the baseline design. Optimization results show a reduction in the objective function of about 30 per cent. A key accomplishment of this paper is the decoupling of the analysis problem and the optimization problems using response surface methods, which should encourage the use of optimization methods by the helicopter industry.

Forecasting Hourly Water Demands With Seasonal Autoregressive Models for Real-Time Application

NASA Astrophysics Data System (ADS)

Chen, Jinduan; Boccelli, Dominic L.

2018-02-01

Consumer water demands are not typically measured at temporal or spatial scales adequate to support real-time decision making, and recent approaches for estimating unobserved demands using observed hydraulic measurements are generally not capable of forecasting demands and uncertainty information. While time series modeling has shown promise for representing total system demands, these models have generally not been evaluated at spatial scales appropriate for representative real-time modeling. This study investigates the use of a double-seasonal time series model to capture daily and weekly autocorrelations to both total system demands and regional aggregated demands at a scale that would capture demand variability across a distribution system. Emphasis was placed on the ability to forecast demands and quantify uncertainties with results compared to traditional time series pattern-based demand models as well as nonseasonal and single-seasonal time series models. Additional research included the implementation of an adaptive-parameter estimation scheme to update the time series model when unobserved changes occurred in the system. For two case studies, results showed that (1) for the smaller-scale aggregated water demands, the log-transformed time series model resulted in improved forecasts, (2) the double-seasonal model outperformed other models in terms of forecasting errors, and (3) the adaptive adjustment of parameters during forecasting improved the accuracy of the generated prediction intervals. These results illustrate the capabilities of time series modeling to forecast both water demands and uncertainty estimates at spatial scales commensurate for real-time modeling applications and provide a foundation for developing a real-time integrated demand-hydraulic model.

Assimilating Satellite SST Observations into a Diurnal Cycle Model

NASA Astrophysics Data System (ADS)

Pimentel, S.; Haines, K.; Nichols, N. K.

2006-12-01

The wealth of satellite sea surface temperature (SST) data now available opens the possibility of large improvements in SST estimation. However the use of such data is not straight forward; a major difficulty in assimilating satellite observations is that they represent a near surface temperature, whereas in ocean models the top level represents the temperature at a greater depth. During the day, under favourable conditions of clear skies and calm winds, the near surface temperature is often seen to have a diurnal cycle that is picked up in satellite observations. Current ocean models do not have the vertical or temporal resolution to adequately represent this daytime warming. The usual approach is to discard daytime observations as they are considered diurnally `corrupted'. A new assimilation technique is developed here that assimilates observations into a diurnal cycle model. The diurnal cycle of SSTs are modelled using a 1-D mixed layer model with fine near surface resolution and 6 hourly forcing from NWP analyses. The accuracy of the SST estimates are hampered by uncertainties in the forcing data. The extent of diurnal SST warming at a particular location and time is predominately governed by a non-linear response to cloud cover and sea surface wind speeds which greatly affect the air-sea fluxes. The method proposed here combines infrared and microwave SST satellite observations in order to derive corrections to the cloud cover and wind speed values over the day. By adjusting the forcing, SST estimation and air-sea fluxes should be improved and are at least more consistent with each other. This new technique for assimilating SST data can be considered a tool for producing more accurate diurnal warming estimates.

A forward model and conjugate gradient inversion technique for low-frequency ultrasonic imaging.

PubMed

van Dongen, Koen W A; Wright, William M D

2006-10-01

Emerging methods of hyperthermia cancer treatment require noninvasive temperature monitoring, and ultrasonic techniques show promise in this regard. Various tomographic algorithms are available that reconstruct sound speed or contrast profiles, which can be related to temperature distribution. The requirement of a high enough frequency for adequate spatial resolution and a low enough frequency for adequate tissue penetration is a difficult compromise. In this study, the feasibility of using low frequency ultrasound for imaging and temperature monitoring was investigated. The transient probing wave field had a bandwidth spanning the frequency range 2.5-320.5 kHz. The results from a forward model which computed the propagation and scattering of low-frequency acoustic pressure and velocity wave fields were used to compare three imaging methods formulated within the Born approximation, representing two main types of reconstruction. The first uses Fourier techniques to reconstruct sound-speed profiles from projection or Radon data based on optical ray theory, seen as an asymptotical limit for comparison. The second uses backpropagation and conjugate gradient inversion methods based on acoustical wave theory. The results show that the accuracy in localization was 2.5 mm or better when using low frequencies and the conjugate gradient inversion scheme, which could be used for temperature monitoring.

Human waves in stadiums

NASA Astrophysics Data System (ADS)

Farkas, I.; Helbing, D.; Vicsek, T.

2003-12-01

Mexican wave first widely broadcasted during the 1986 World Cup held in Mexico, is a human wave moving along the stands of stadiums as one section of spectators stands up, arms lifting, then sits down as the next section does the same. Here we use variants of models originally developed for the description of excitable media to demonstrate that this collective human behaviour can be quantitatively interpreted by methods of statistical physics. Adequate modelling of reactions to triggering attempts provides a deeper insight into the mechanisms by which a crowd can be stimulated to execute a particular pattern of behaviour and represents a possible tool of control during events involving excited groups of people. Interactive simulations, video recordings and further images are available at the webpage dedicated to this work: http://angel.elte.hu/wave.

Pollution concentrations in runoff water from refuse piles

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

Guin, J.A.

1977-03-01

In the processes of removal, refinement and disposal of raw materials, large quantities of waste products become exposed to weathering forces. Subsequent percolation, flushing, and oxidation results in the pollution of waterways, low-lying farmlands and underground aquifers with acidity, alkalinity, hardness, heavy metals, and undesirable organic materials such as tannin and lignin. The need for methodology for estimating the chemical nature and quantity of these leachates becomes more compelling as the extraction of natural materials accelerates. In this work a mass transfer model is formulated which describes the leaching of such pollutants from refuse piles. The model is applied tomore » an actual refuse pile under natural precipitation and weathering conditions and found to adequately represent the pollutant concentrations in the rainfall runoff.« less

Improving Aerosol Simulation over South Asia for Climate and Air Quality Studies

NASA Technical Reports Server (NTRS)

Pan, Xiaohua; Chin, Mian; Bian, Huisheng; Gautam, Ritesh

2014-01-01

Atmospheric pollution over South Asia attracts special attention due to its effects on regional climate, the water cycle, and human health. These effects are potentially growing owing to rising trends of anthropogenic aerosol emissions found there. However, it has been proved quite challenging to adequately represent the aerosol spatial distribution and magnitude over this critical region in global models (Pan et al. 2014), with the surface concentrations, aerosol optical depth (AOD), and absorbing AOD (AAOD) significantly underestimated, especially in October-January when the agricultural waste burning and anthropogenic aerosol dominate over dust aerosol. In this study, we aim to investigate the causes for such discrepancy in winter by conducting sets of model experiments with NASA's GEOS-5 in terms of (1) spatial resolution, (2) emission amount, and (3) meteorological fields.

Schwarzschild and linear potentials in Mannheim's model of conformal gravity

NASA Astrophysics Data System (ADS)

Phillips, Peter R.

2018-05-01

We study the equations of conformal gravity, as given by Mannheim, in the weak field limit, so that a linear approximation is adequate. Specialising to static fields with spherical symmetry, we obtain a second-order equation for one of the metric functions. We obtain the Green function for this equation, and represent the metric function in the form of integrals over the source. Near a compact source such as the Sun the solution no longer has a form that is compatible with observations. We conclude that a solution of Mannheim type (a Schwarzschild term plus a linear potential of galactic scale) cannot exist for these field equations.

Propagating Qualitative Values Through Quantitative Equations

NASA Technical Reports Server (NTRS)

Kulkarni, Deepak

1992-01-01

In most practical problems where traditional numeric simulation is not adequate, one need to reason about a system with both qualitative and quantitative equations. In this paper, we address the problem of propagating qualitative values represented as interval values through quantitative equations. Previous research has produced exponential-time algorithms for approximate solution of the problem. These may not meet the stringent requirements of many real time applications. This paper advances the state of art by producing a linear-time algorithm that can propagate a qualitative value through a class of complex quantitative equations exactly and through arbitrary algebraic expressions approximately. The algorithm was found applicable to Space Shuttle Reaction Control System model.

A Two-Factor Model Better Explains Heterogeneity in Negative Symptoms: Evidence from the Positive and Negative Syndrome Scale.

PubMed

Jang, Seon-Kyeong; Choi, Hye-Im; Park, Soohyun; Jaekal, Eunju; Lee, Ga-Young; Cho, Young Il; Choi, Kee-Hong

2016-01-01

Acknowledging separable factors underlying negative symptoms may lead to better understanding and treatment of negative symptoms in individuals with schizophrenia. The current study aimed to test whether the negative symptoms factor (NSF) of the Positive and Negative Syndrome Scale (PANSS) would be better represented by expressive and experiential deficit factors, rather than by a single factor model, using confirmatory factor analysis (CFA). Two hundred and twenty individuals with schizophrenia spectrum disorders completed the PANSS; subsamples additionally completed the Brief Negative Symptom Scale (BNSS) and the Motivation and Pleasure Scale-Self-Report (MAP-SR). CFA results indicated that the two-factor model fit the data better than the one-factor model; however, latent variables were closely correlated. The two-factor model's fit was significantly improved by accounting for correlated residuals between N2 (emotional withdrawal) and N6 (lack of spontaneity and flow of conversation), and between N4 (passive social withdrawal) and G16 (active social avoidance), possibly reflecting common method variance. The two NSF factors exhibited differential patterns of correlation with subdomains of the BNSS and MAP-SR. These results suggest that the PANSS NSF would be better represented by a two-factor model than by a single-factor one, and support the two-factor model's adequate criterion-related validity. Common method variance among several items may be a potential source of measurement error under a two-factor model of the PANSS NSF.

42 CFR 67.15 - Peer review of applications.

Code of Federal Regulations, 2010 CFR

2010-10-01

...; (viii) The extent to which women and minorities are adequately represented in study populations; (ix... conference, specifically the importance of the issue or problem being addressed, including methodological or...

42 CFR 67.15 - Peer review of applications.

Code of Federal Regulations, 2012 CFR

2012-10-01

...; (viii) The extent to which women and minorities are adequately represented in study populations; (ix... conference, specifically the importance of the issue or problem being addressed, including methodological or...

42 CFR 67.15 - Peer review of applications.

Code of Federal Regulations, 2011 CFR

2011-10-01

...; (viii) The extent to which women and minorities are adequately represented in study populations; (ix... conference, specifically the importance of the issue or problem being addressed, including methodological or...

42 CFR 67.15 - Peer review of applications.

Code of Federal Regulations, 2014 CFR

2014-10-01

...; (viii) The extent to which women and minorities are adequately represented in study populations; (ix... conference, specifically the importance of the issue or problem being addressed, including methodological or...

42 CFR 67.15 - Peer review of applications.

Code of Federal Regulations, 2013 CFR

2013-10-01

...; (viii) The extent to which women and minorities are adequately represented in study populations; (ix... conference, specifically the importance of the issue or problem being addressed, including methodological or...

77 FR 34337 - Lake Tahoe Federal Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-11

... associations, (8) education, (9) property rights advocates, (10) science and research, (11) California local... adequately represented on the LTFAC. We encourage and welcome applications for qualified female, minority, or...

SAMPEX/PET model of the low altitude trapped proton environment

NASA Astrophysics Data System (ADS)

Heynderickx, D.; Looper, M. D.; Blake, J. B.

The low-altitude trapped proton population exhibits strong time variations related to geomagnetic secular variation and neutral atmosphere conditions. The flux measurements of the Proton Electron Telescope (PET) onboard the polar satellite SAMPEX constitute an adequate data set to distinguish different time scales and to characterise the respective variations. As a first step towards building a dynamic model of the low altitude proton environment we binned the 1995-1996 PET data into a model map with functional dependencies of the proton fluxes on the F10.7 solar radio flux and on the time of year to represent variations on the time scale of the solar cycle and seasonal variations. Now, a full solar cycle of SAMPEX/PET data is available, so that the preliminary model could be extended. The secular variation of the geomagnetic field is included in the model, as it is constructed using Kaufmann's K=I √{B} instead of McIlwain's L as a map coordinate.

Osteosarcoma Models: From Cell Lines to Zebrafish

PubMed Central

Mohseny, Alexander B.; Hogendoorn, Pancras C. W.; Cleton-Jansen, Anne-Marie

2012-01-01

High-grade osteosarcoma is an aggressive tumor most commonly affecting adolescents. The early age of onset might suggest genetic predisposition; however, the vast majority of the tumors are sporadic. Early onset, most often lack of a predisposing condition or lesion, only infrequent (<2%) prevalence of inheritance, extensive genomic instability, and a wide histological heterogeneity are just few factors to mention that make osteosarcoma difficult to study. Therefore, it is sensible to design and use models representative of the human disease. Here we summarize multiple osteosarcoma models established in vitro and in vivo, comment on their utilities, and highlight newest achievements, such as the use of zebrafish embryos. We conclude that to gain a better understanding of osteosarcoma, simplification of this extremely complex tumor is needed. Therefore, we parse the osteosarcoma problem into parts and propose adequate models to study them each separately. A better understanding of osteosarcoma provides opportunities for discovering and assaying novel effective treatment strategies. “Sometimes the model is more interesting than the original disease” PJ Hoedemaeker (1937–2007). PMID:22566751

Image Discrimination Models With Stochastic Channel Selection

NASA Technical Reports Server (NTRS)

Ahumada, Albert J., Jr.; Beard, Bettina L.; Null, Cynthia H. (Technical Monitor)

1995-01-01

Many models of human image processing feature a large fixed number of channels representing cortical units varying in spatial position (visual field direction and eccentricity) and spatial frequency (radial frequency and orientation). The values of these parameters are usually sampled at fixed values selected to ensure adequate overlap considering the bandwidth and/or spread parameters, which are usually fixed. Even high levels of overlap does not always ensure that the performance of the model will vary smoothly with image translation or scale changes. Physiological measurements of bandwidth and/or spread parameters result in a broad distribution of estimated parameter values and the prediction of some psychophysical results are facilitated by the assumption that these parameters also take on a range of values. Selecting a sample of channels from a continuum of channels rather than using a fixed set can make model performance vary smoothly with changes in image position, scale, and orientation. It also facilitates the addition of spatial inhomogeneity, nonlinear feature channels, and focus of attention to channel models.

Representing spatial information in a computational model for network management

NASA Technical Reports Server (NTRS)

Blaisdell, James H.; Brownfield, Thomas F.

1994-01-01

While currently available relational database management systems (RDBMS) allow inclusion of spatial information in a data model, they lack tools for presenting this information in an easily comprehensible form. Computer-aided design (CAD) software packages provide adequate functions to produce drawings, but still require manual placement of symbols and features. This project has demonstrated a bridge between the data model of an RDBMS and the graphic display of a CAD system. It is shown that the CAD system can be used to control the selection of data with spatial components from the database and then quickly plot that data on a map display. It is shown that the CAD system can be used to extract data from a drawing and then control the insertion of that data into the database. These demonstrations were successful in a test environment that incorporated many features of known working environments, suggesting that the techniques developed could be adapted for practical use.

Better models are more effectively connected models

NASA Astrophysics Data System (ADS)

Nunes, João Pedro; Bielders, Charles; Darboux, Frederic; Fiener, Peter; Finger, David; Turnbull-Lloyd, Laura; Wainwright, John

2016-04-01

The concept of hydrologic and geomorphologic connectivity describes the processes and pathways which link sources (e.g. rainfall, snow and ice melt, springs, eroded areas and barren lands) to accumulation areas (e.g. foot slopes, streams, aquifers, reservoirs), and the spatial variations thereof. There are many examples of hydrological and sediment connectivity on a watershed scale; in consequence, a process-based understanding of connectivity is crucial to help managers understand their systems and adopt adequate measures for flood prevention, pollution mitigation and soil protection, among others. Modelling is often used as a tool to understand and predict fluxes within a catchment by complementing observations with model results. Catchment models should therefore be able to reproduce the linkages, and thus the connectivity of water and sediment fluxes within the systems under simulation. In modelling, a high level of spatial and temporal detail is desirable to ensure taking into account a maximum number of components, which then enables connectivity to emerge from the simulated structures and functions. However, computational constraints and, in many cases, lack of data prevent the representation of all relevant processes and spatial/temporal variability in most models. In most cases, therefore, the level of detail selected for modelling is too coarse to represent the system in a way in which connectivity can emerge; a problem which can be circumvented by representing fine-scale structures and processes within coarser scale models using a variety of approaches. This poster focuses on the results of ongoing discussions on modelling connectivity held during several workshops within COST Action Connecteur. It assesses the current state of the art of incorporating the concept of connectivity in hydrological and sediment models, as well as the attitudes of modellers towards this issue. The discussion will focus on the different approaches through which connectivity can be represented in models: either by allowing it to emerge from model behaviour or by parameterizing it inside model structures; and on the appropriate scale at which processes should be represented explicitly or implicitly. It will also explore how modellers themselves approach connectivity through the results of a community survey. Finally, it will present the outline of an international modelling exercise aimed at assessing how different modelling concepts can capture connectivity in real catchments.

Challenges to Applying a Metamodel for Groundwater Flow Beyond Underlying Numerical Model Boundaries

NASA Astrophysics Data System (ADS)

Reeves, H. W.; Fienen, M. N.; Feinstein, D.

2015-12-01

Metamodels of environmental behavior offer opportunities for decision support, adaptive management, and increased stakeholder engagement through participatory modeling and model exploration. Metamodels are derived from calibrated, computationally demanding, numerical models. They may potentially be applied to non-modeled areas to provide screening or preliminary analysis tools for areas that do not yet have the benefit of more comprehensive study. In this decision-support mode, they may be fulfilling a role often accomplished by application of analytical solutions. The major challenge to transferring a metamodel to a non-modeled area is how to quantify the spatial data in the new area of interest in such a way that it is consistent with the data used to derive the metamodel. Tests based on transferring a metamodel derived from a numerical groundwater-flow model of the Lake Michigan Basin to other glacial settings across the northern U.S. show that the spatial scale of the numerical model must be appropriately scaled to adequately represent different settings. Careful GIS analysis of the numerical model, metamodel, and new area of interest is required for successful transfer of results.

Developing a model for the adequate description of electronic communication in hospitals.

PubMed

Saboor, Samrend; Ammenwerth, Elske

2011-01-01

Adequate information and communication systems (ICT) can help to improve the communication in hospitals. Changes to the ICT-infrastructure of hospitals must be planed carefully. In order to support a comprehensive planning, we presented a classification of 81 common errors of the electronic communication on the MIE 2008 congress. Our objective now was to develop a data model that defines specific requirements for an adequate description of electronic communication processes We first applied the method of explicating qualitative content analysis on the error categorization in order to determine the essential process details. After this, we applied the method of subsuming qualitative content analysis on the results of the first step. A data model for the adequate description of electronic communication. This model comprises 61 entities and 91 relationships. The data model comprises and organizes all details that are necessary for the detection of the respective errors. It can be for either used to extend the capabilities of existing modeling methods or as a basis for the development of a new approach.

12 CFR 19.195 - Incompetence.

Code of Federal Regulations, 2010 CFR

2010-01-01

... grounds for suspension or debarment. The term “incompetence” encompasses conduct that reflects a lack of... exercise in adequately representing the rights and interests of a client. Such conduct includes, but is not...

Representative Nature of Scientific Literacy Themes in a High School Chemistry Course: The Case of Zambia

ERIC Educational Resources Information Center

Mumba, Frackson; Hunter, William J. F.

2009-01-01

The purpose of this study was to find out how the scientific literacy themes are represented in the current Zambian high school chemistry syllabus, textbooks and grade twelve chemistry examination papers in an attempt to find out whether or not the chemistry course has adequate potential to contribute to the preparation of scientifically literate…

Identifying Opportunities for Improving the Quality of Life of Older Age Groups.

ERIC Educational Resources Information Center

Flanagan, John C.

The situations and feelings of representative national samples of 50- and 70-year-olds were investigated in order to provide a representative, adequate data base for planning programs and policies that will result in maximum improvement in the quality of life of older Americans at minimum costs to taxpayers. Intensive case studies of 1,000…

Evaluating reliability of WSN with sleep/wake-up interfering nodes

NASA Astrophysics Data System (ADS)

Distefano, Salvatore

2013-10-01

A wireless sensor network (WSN) (singular and plural of acronyms are spelled the same) is a distributed system composed of autonomous sensor nodes wireless connected and randomly scattered into a geographical area to cooperatively monitor physical or environmental conditions. Adequate techniques and strategies are required to manage a WSN so that it works properly, observing specific quantities and metrics to evaluate the WSN operational conditions. Among them, one of the most important is the reliability. Considering a WSN as a system composed of sensor nodes the system reliability approach can be applied, thus expressing the WSN reliability in terms of its nodes' reliability. More specifically, since often standby power management policies are applied at node level and interferences among nodes may arise, a WSN can be considered as a dynamic system. In this article we therefore consider the WSN reliability evaluation problem from the dynamic system reliability perspective. Static-structural interactions are specified by the WSN topology. Sleep/wake-up standby policies and interferences due to wireless communications can be instead considered as dynamic aspects. Thus, in order to represent and to evaluate the WSN reliability, we use dynamic reliability block diagrams and Petri nets. The proposed technique allows to overcome the limits of Markov models when considering non-linear discharge processes, since they cannot adequately represent the aging processes. In order to demonstrate the effectiveness of the technique, we investigate some specific WSN network topologies, providing guidelines for their representation and evaluation.

Large eddy simulation of turbulent premixed combustion using tabulated detailed chemistry and presumed probability density function

NASA Astrophysics Data System (ADS)

Zhang, Hongda; Han, Chao; Ye, Taohong; Ren, Zhuyin

2016-03-01

A method of chemistry tabulation combined with presumed probability density function (PDF) is applied to simulate piloted premixed jet burner flames with high Karlovitz number using large eddy simulation. Thermo-chemistry states are tabulated by the combination of auto-ignition and extended auto-ignition model. To evaluate the predictive capability of the proposed tabulation method to represent the thermo-chemistry states under the condition of different fresh gases temperature, a-priori study is conducted by performing idealised transient one-dimensional premixed flame simulations. Presumed PDF is used to involve the interaction of turbulence and flame with beta PDF to model the reaction progress variable distribution. Two presumed PDF models, Dirichlet distribution and independent beta distribution, respectively, are applied for representing the interaction between two mixture fractions that are associated with three inlet streams. Comparisons of statistical results show that two presumed PDF models for the two mixture fractions are both capable of predicting temperature and major species profiles, however, they are shown to have a significant effect on the predictions for intermediate species. An analysis of the thermo-chemical state-space representation of the sub-grid scale (SGS) combustion model is performed by comparing correlations between the carbon monoxide mass fraction and temperature. The SGS combustion model based on the proposed chemistry tabulation can reasonably capture the peak value and change trend of intermediate species. Aspects regarding model extensions to adequately predict the peak location of intermediate species are discussed.

A Bifactor Approach to Model Multifaceted Constructs in Statistical Mediation Analysis.

PubMed

Gonzalez, Oscar; MacKinnon, David P

Statistical mediation analysis allows researchers to identify the most important mediating constructs in the causal process studied. Identifying specific mediators is especially relevant when the hypothesized mediating construct consists of multiple related facets. The general definition of the construct and its facets might relate differently to an outcome. However, current methods do not allow researchers to study the relationships between general and specific aspects of a construct to an outcome simultaneously. This study proposes a bifactor measurement model for the mediating construct as a way to parse variance and represent the general aspect and specific facets of a construct simultaneously. Monte Carlo simulation results are presented to help determine the properties of mediated effect estimation when the mediator has a bifactor structure and a specific facet of a construct is the true mediator. This study also investigates the conditions when researchers can detect the mediated effect when the multidimensionality of the mediator is ignored and treated as unidimensional. Simulation results indicated that the mediation model with a bifactor mediator measurement model had unbiased and adequate power to detect the mediated effect with a sample size greater than 500 and medium a - and b -paths. Also, results indicate that parameter bias and detection of the mediated effect in both the data-generating model and the misspecified model varies as a function of the amount of facet variance represented in the mediation model. This study contributes to the largely unexplored area of measurement issues in statistical mediation analysis.

GCIP water and energy budget synthesis (WEBS)

USGS Publications Warehouse

Roads, J.; Lawford, R.; Bainto, E.; Berbery, E.; Chen, S.; Fekete, B.; Gallo, K.; Grundstein, A.; Higgins, W.; Kanamitsu, M.; Krajewski, W.; Lakshmi, V.; Leathers, D.; Lettenmaier, D.; Luo, L.; Maurer, E.; Meyers, T.; Miller, D.; Mitchell, Ken; Mote, T.; Pinker, R.; Reichler, T.; Robinson, D.; Robock, A.; Smith, J.; Srinivasan, G.; Verdin, K.; Vinnikov, K.; Vonder, Haar T.; Vorosmarty, C.; Williams, S.; Yarosh, E.

2003-01-01

As part of the World Climate Research Program's (WCRPs) Global Energy and Water-Cycle Experiment (GEWEX) Continental-scale International Project (GCIP), a preliminary water and energy budget synthesis (WEBS) was developed for the period 1996-1999 fromthe "best available" observations and models. Besides this summary paper, a companion CD-ROM with more extensive discussion, figures, tables, and raw data is available to the interested researcher from the GEWEX project office, the GAPP project office, or the first author. An updated online version of the CD-ROM is also available at http://ecpc.ucsd.edu/gcip/webs.htm/. Observations cannot adequately characterize or "close" budgets since too many fundamental processes are missing. Models that properly represent the many complicated atmospheric and near-surface interactions are also required. This preliminary synthesis therefore included a representative global general circulation model, regional climate model, and a macroscale hydrologic model as well as a global reanalysis and a regional analysis. By the qualitative agreement among the models and available observations, it did appear that we now qualitatively understand water and energy budgets of the Mississippi River Basin. However, there is still much quantitative uncertainty. In that regard, there did appear to be a clear advantage to using a regional analysis over a global analysis or a regional simulation over a global simulation to describe the Mississippi River Basin water and energy budgets. There also appeared to be some advantage to using a macroscale hydrologic model for at least the surface water budgets. Copyright 2003 by the American Geophysical Union.

Using Multitheory Model of Health Behavior Change to Predict Adequate Sleep Behavior.

PubMed

Knowlden, Adam P; Sharma, Manoj; Nahar, Vinayak K

The purpose of this article was to use the multitheory model of health behavior change in predicting adequate sleep behavior in college students. A valid and reliable survey was administered in a cross-sectional design (n = 151). For initiation of adequate sleep behavior, the construct of behavioral confidence (P < .001) was found to be significant and accounted for 24.4% of the variance. For sustenance of adequate sleep behavior, changes in social environment (P < .02), emotional transformation (P < .001), and practice for change (P < .001) were significant and accounted for 34.2% of the variance.

Modeling Carbon-Black/Polymer Composite Sensors

PubMed Central

Lei, Hua; Pitt, William G.; McGrath, Lucas K.; Ho, Clifford K.

2012-01-01

Conductive polymer composite sensors have shown great potential in identifying gaseous analytes. To more thoroughly understand the physical and chemical mechanisms of this type of sensor, a mathematical model was developed by combining two sub-models: a conductivity model and a thermodynamic model, which gives a relationship between the vapor concentration of analyte(s) and the change of the sensor signals. In this work, 64 chemiresistors representing eight different carbon concentrations (8–60 vol% carbon) were constructed by depositing thin films of a carbon-black/polyisobutylene composite onto concentric spiral platinum electrodes on a silicon chip. The responses of the sensors were measured in dry air and at various vapor pressures of toluene and trichloroethylene. Three parameters in the conductivity model were determined by fitting the experimental data. It was shown that by applying this model, the sensor responses can be adequately predicted for given vapor pressures; furthermore the analyte vapor concentrations can be estimated based on the sensor responses. This model will guide the improvement of the design and fabrication of conductive polymer composite sensors for detecting and identifying mixtures of organic vapors. PMID:22518071

Lyman-α Models for LRO LAMP from MESSENGER MASCS and SOHO SWAN Data

NASA Astrophysics Data System (ADS)

Pryor, Wayne R.; Holsclaw, Gregory M.; McClintock, William E.; Snow, Martin; Vervack, Ronald J.; Gladstone, G. Randall; Stern, S. Alan; Retherford, Kurt D.; Miles, Paul F.

From models of the interplanetary Lyman-α glow derived from observations by the Mercury Atmospheric and Surface Composition Spectrometer (MASCS) interplanetary Lyman-α data obtained in 2009-2011 on the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft mission, daily all-sky Lyman-α maps were generated for use by the Lunar Reconnaissance Orbiter (LRO) LAMP Lyman-Alpha Mapping Project (LAMP) experiment. These models were then compared with Solar and Heliospheric Observatory (SOHO) Solar Wind ANistropy (SWAN) Lyman-α maps when available. Although the empirical agreement across the sky between the scaled model and the SWAN maps is adequate for LAMP mapping purposes, the model brightness values best agree with the SWAN values in 2008 and 2009. SWAN's observations show a systematic decline in 2010 and 2011 relative to the model. It is not clear if the decline represents a failure of the model or a decline in sensitivity in SWAN in 2010 and 2011. MESSENGER MASCS and SOHO SWAN Lyman-α calibrations systematically differ in comparison with the model, with MASCS reporting Lyman-α values some 30 % lower than SWAN.

Hydrological simulation of Sperchios River basin in Central Greece using the MIKE SHE model and geographic information systems

NASA Astrophysics Data System (ADS)

Paparrizos, Spyridon; Maris, Fotios

2017-05-01

The MIKE SHE model is able to simulate the entire stream flow which includes direct and basic flow. Many models either do not simulate or use simplistic methods to determine the basic flow. The MIKE SHE model takes into account many hydrological data. Since this study was directed towards the simulation of surface runoff and infiltration into saturated and unsaturated zone, the MIKE SHE is an appropriate model for reliable conclusions. In the current research, the MIKE SHE model was used to simulate runoff in the area of Sperchios River basin. Meteorological data from eight rainfall stations within the Sperchios River basin were used as inputs. Vegetation as well as geological data was used to perform the calibration and validation of the physical processes of the model. Additionally, ArcGIS program was used. The results indicated that the model was able to simulate the surface runoff satisfactorily, representing all the hydrological data adequately. Some minor differentiations appeared which can be eliminated with the appropriate adjustments that can be decided by the researcher's experience.

Sampling Strategies and Processing of Biobank Tissue Samples from Porcine Biomedical Models.

PubMed

Blutke, Andreas; Wanke, Rüdiger

2018-03-06

In translational medical research, porcine models have steadily become more popular. Considering the high value of individual animals, particularly of genetically modified pig models, and the often-limited number of available animals of these models, establishment of (biobank) collections of adequately processed tissue samples suited for a broad spectrum of subsequent analyses methods, including analyses not specified at the time point of sampling, represent meaningful approaches to take full advantage of the translational value of the model. With respect to the peculiarities of porcine anatomy, comprehensive guidelines have recently been established for standardized generation of representative, high-quality samples from different porcine organs and tissues. These guidelines are essential prerequisites for the reproducibility of results and their comparability between different studies and investigators. The recording of basic data, such as organ weights and volumes, the determination of the sampling locations and of the numbers of tissue samples to be generated, as well as their orientation, size, processing and trimming directions, are relevant factors determining the generalizability and usability of the specimen for molecular, qualitative, and quantitative morphological analyses. Here, an illustrative, practical, step-by-step demonstration of the most important techniques for generation of representative, multi-purpose biobank specimen from porcine tissues is presented. The methods described here include determination of organ/tissue volumes and densities, the application of a volume-weighted systematic random sampling procedure for parenchymal organs by point-counting, determination of the extent of tissue shrinkage related to histological embedding of samples, and generation of randomly oriented samples for quantitative stereological analyses, such as isotropic uniform random (IUR) sections generated by the "Orientator" and "Isector" methods, and vertical uniform random (VUR) sections.

America's Teacher Colleges: Are They Making the Grade? Hearing before the Subcommittee on 21st Century Competitiveness of the Committee on Education and the Workforce. House of Representatives, One Hundred Eighth Congress, First Session (May 20, 2003).

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. House Committee on Education and the Workforce.

A hearing was held to explore whether U. S. teachers' colleges are doing an adequate job. Opening statements by Representative Howard P. McKeon and Representative Dale Kildee set the stage for the testimony of these witnesses: (1) Lisa Graham Keegan, Chief Executive Officer, Education Leaders Council; (2) Kati Haycock, Director, The Education…

Retrieval of Venus' cloud parameters from VIRTIS nightside spectra in the latitude band 25°-55°N

NASA Astrophysics Data System (ADS)

Magurno, Davide; Maestri, Tiziano; Grassi, Davide; Piccioni, Giuseppe; Sindoni, Giuseppe

2017-09-01

Two years of data from the M-channel of the Visible and InfraRed Thermal Imaging Spectrometer (VIRTIS), on board the European Space Agency mission Venus Express operating around the planet Venus, are analysed. Nocturnal data from a nadir viewpoint in the latitude band 25°N-55°N are selected for their configuration advantages and maximisation of the scene homogeneity. A reference model, and radiance spectrum, is defined based on average accepted values of the Venus main atmospheric and cloud parameters found in the literature. Extensive radiative transfer simulations are performed to provide a synthetic database of more than 10 000 VIRTIS radiances representing the natural variability of the system parameters (atmospheric temperature profile, cloud H2Osbnd H2SO4 solution concentration and vertical distribution, particle size distribution density and modal radius). A simulated-observed fitting algorithm of spectral radiances in window channels, based on a weighting procedure accounting for the latitudinal observed radiance variations, is used to derive the best atmosphere-cloud configuration for each observation. Results show that the reference Venus model does not adequately reproduce the observed VIRTIS spectra. In particular, the model accounting for a constant sulphuric acid concentration along the vertical extent of the clouds is never selected as a best fit. The 75%/96% and 84%/96% concentrations (the first values refer to the upper cloud layers and the second values to the lower ones) are the most commonly retrieved models representing more than 85% of the retrieved cases for any latitudinal band considered. It is shown that the assumption of stratified concentration of aqueous sulphuric acid allows to adequately fit the observed radiance, in particular the peak at 1.74 μm and around 4 μm. The analysis of the results concerning the microphysics suggests larger radii for the upper cloud layers in conjunction with a large reduction of their number density with respect to the reference standard. Considerable variation of the particle concentration in the Venus' atmosphere is retrieved for altitudes between 60 and 70 km. The retrieved models also suggest that lower cloud layers have smaller particle radii and larger number density than expected from the reference model. Latitudinal variations of microphysical and chemical parameters are also analysed.

Independent Review of Simulation of Net Infiltration for Present-Day and Potential Future Climates

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

Review Panel: Soroosh Sorooshian, Ph.D., Panel Chairperson, University of California, Irvine; Jan M. H. Hendrickx, Ph.D., New Mexico Institute of Mining and Technology; Binayak P. Mohanty, Ph.D., Texas A&M University

The DOE Office of Civilian Radioactive Waste Management (OCRWM) tasked Oak Ridge Institute for Science and Education (ORISE) with providing an independent expert review of the documented model and prediction results for net infiltration of water into the unsaturated zone at Yucca Mountain. The specific purpose of the model, as documented in the report MDL-NBS-HS-000023, Rev. 01, is “to provide a spatial representation, including epistemic and aleatory uncertainty, of the predicted mean annual net infiltration at the Yucca Mountain site ...” (p. 1-1) The expert review panel assembled by ORISE concluded that the model report does not provide a technicallymore » credible spatial representation of net infiltration at Yucca Mountain. Specifically, the ORISE Review Panel found that: • A critical lack of site-specific meteorological, surface, and subsurface information prevents verification of (i) the net infiltration estimates, (ii) the uncertainty estimates of parameters caused by their spatial variability, and (iii) the assumptions used by the modelers (ranges and distributions) for the characterization of parameters. The paucity of site-specific data used by the modeling team for model implementation and validation is a major deficiency in this effort. • The model does not incorporate at least one potentially important hydrologic process. Subsurface lateral flow is not accounted for by the model, and the assumption that the effect of subsurface lateral flow is negligible is not adequately justified. This issue is especially critical for the wetter climate periods. This omission may be one reason the model results appear to underestimate net infiltration beneath wash environments and therefore imprecisely represent the spatial variability of net infiltration. • While the model uses assumptions consistently, such as uniform soil depths and a constant vegetation rooting depth, such assumptions may not be appropriate for this net infiltration simulation because they oversimplify a complex landscape and associated hydrologic processes, especially since the model assumptions have not been adequately corroborated by field and laboratory observations at Yucca Mountain.« less

A modulating effect of Tropical Instability Wave (TIW)-induced surface wind feedback in a hybrid coupled model of the tropical Pacific

NASA Astrophysics Data System (ADS)

Zhang, Rong-Hua

2016-10-01

Tropical Instability Waves (TIWs) and the El Niño-Southern Oscillation (ENSO) are two air-sea coupling phenomena that are prominent in the tropical Pacific, occurring at vastly different space-time scales. It has been challenging to adequately represent both of these processes within a large-scale coupled climate model, which has led to a poor understanding of the interactions between TIW-induced feedback and ENSO. In this study, a novel modeling system was developed that allows representation of TIW-scale air-sea coupling and its interaction with ENSO. Satellite data were first used to derive an empirical model for TIW-induced sea surface wind stress perturbations (τTIW). The model was then embedded in a basin-wide hybrid-coupled model (HCM) of the tropical Pacific. Because τTIW were internally determined from TIW-scale sea surface temperatures (SSTTIW) simulated in the ocean model, the wind-SST coupling at TIW scales was interactively represented within the large-scale coupled model. Because the τTIW-SSTTIW coupling part of the model can be turned on or off in the HCM simulations, the related TIW wind feedback effects can be isolated and examined in a straightforward way. Then, the TIW-scale wind feedback effects on the large-scale mean ocean state and interannual variability in the tropical Pacific were investigated based on this embedded system. The interactively represented TIW-scale wind forcing exerted an asymmetric influence on SSTs in the HCM, characterized by a mean-state cooling and by a positive feedback on interannual variability, acting to enhance ENSO amplitude. Roughly speaking, the feedback tends to increase interannual SST variability by approximately 9%. Additionally, there is a tendency for TIW wind to have an effect on the phase transition during ENSO evolution, with slightly shortened interannual oscillation periods. Additional sensitivity experiments were performed to elucidate the details of TIW wind effects on SST evolution during ENSO cycles.

Modeling of a thermal energy storage system based on coupled metal hydrides (magnesium iron – sodium alanate) for concentrating solar power plants

DOE PAGES

d'Entremont, A.; Corgnale, C.; Sulic, M.; ...

2017-08-31

Concentrating solar power plants represent low cost and efficient solutions for renewable electricity production only if adequate thermal energy storage systems are included. Metal hydride thermal energy storage systems have demonstrated the potential to achieve very high volumetric energy densities, high exergetic efficiencies, and low costs. The current work analyzes the technical feasibility and the performance of a storage system based on the high temperature Mg 2FeH 6 hydride coupled with the low temperature Na 3AlH 6 hydride. To accomplish this, a detailed transport model has been set up and the coupled metal hydride system has been simulated based onmore » a laboratory scale experimental configuration. Proper kinetics expressions have been developed and included in the model to replicate the absorption and desorption process in the high temperature and low temperature hydride materials. The system showed adequate hydrogen transfer between the two metal hydrides, with almost complete charging and discharging, during both thermal energy storage and thermal energy release. The system operating temperatures varied from 450°C to 500°C, with hydrogen pressures between 30 bar and 70 bar. This makes the thermal energy storage system a suitable candidate for pairing with a solar driven steam power plant. The model results, obtained for the selected experimental configuration, showed an actual thermal energy storage system volumetric energy density of about 132 kWh/m 3, which is more than 5 times the U.S. Department of Energy SunShot target (25 kWh/m 3).« less

Development of a neural-based forecasting tool to classify recreational water quality using fecal indicator organisms.

PubMed

Motamarri, Srinivas; Boccelli, Dominic L

2012-09-15

Users of recreational waters may be exposed to elevated pathogen levels through various point/non-point sources. Typical daily notifications rely on microbial analysis of indicator organisms (e.g., Escherichia coli) that require 18, or more, hours to provide an adequate response. Modeling approaches, such as multivariate linear regression (MLR) and artificial neural networks (ANN), have been utilized to provide quick predictions of microbial concentrations for classification purposes, but generally suffer from high false negative rates. This study introduces the use of learning vector quantization (LVQ)--a direct classification approach--for comparison with MLR and ANN approaches and integrates input selection for model development with respect to primary and secondary water quality standards within the Charles River Basin (Massachusetts, USA) using meteorologic, hydrologic, and microbial explanatory variables. Integrating input selection into model development showed that discharge variables were the most important explanatory variables while antecedent rainfall and time since previous events were also important. With respect to classification, all three models adequately represented the non-violated samples (>90%). The MLR approach had the highest false negative rates associated with classifying violated samples (41-62% vs 13-43% (ANN) and <16% (LVQ)) when using five or more explanatory variables. The ANN performance was more similar to LVQ when a larger number of explanatory variables were utilized, but the ANN performance degraded toward MLR performance as explanatory variables were removed. Overall, the use of LVQ as a direct classifier provided the best overall classification ability with respect to violated/non-violated samples for both standards. Copyright © 2012 Elsevier Ltd. All rights reserved.

Modeling of a thermal energy storage system based on coupled metal hydrides (magnesium iron – sodium alanate) for concentrating solar power plants

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

d'Entremont, A.; Corgnale, C.; Sulic, M.

Concentrating solar power plants represent low cost and efficient solutions for renewable electricity production only if adequate thermal energy storage systems are included. Metal hydride thermal energy storage systems have demonstrated the potential to achieve very high volumetric energy densities, high exergetic efficiencies, and low costs. The current work analyzes the technical feasibility and the performance of a storage system based on the high temperature Mg 2FeH 6 hydride coupled with the low temperature Na 3AlH 6 hydride. To accomplish this, a detailed transport model has been set up and the coupled metal hydride system has been simulated based onmore » a laboratory scale experimental configuration. Proper kinetics expressions have been developed and included in the model to replicate the absorption and desorption process in the high temperature and low temperature hydride materials. The system showed adequate hydrogen transfer between the two metal hydrides, with almost complete charging and discharging, during both thermal energy storage and thermal energy release. The system operating temperatures varied from 450°C to 500°C, with hydrogen pressures between 30 bar and 70 bar. This makes the thermal energy storage system a suitable candidate for pairing with a solar driven steam power plant. The model results, obtained for the selected experimental configuration, showed an actual thermal energy storage system volumetric energy density of about 132 kWh/m 3, which is more than 5 times the U.S. Department of Energy SunShot target (25 kWh/m 3).« less

Engineering Bacteria to Search for Specific Concentrations of Molecules by a Systematic Synthetic Biology Design Method

PubMed Central

Chen, Bor-Sen

2016-01-01

Bacteria navigate environments full of various chemicals to seek favorable places for survival by controlling the flagella’s rotation using a complicated signal transduction pathway. By influencing the pathway, bacteria can be engineered to search for specific molecules, which has great potential for application to biomedicine and bioremediation. In this study, genetic circuits were constructed to make bacteria search for a specific molecule at particular concentrations in their environment through a synthetic biology method. In addition, by replacing the “brake component” in the synthetic circuit with some specific sensitivities, the bacteria can be engineered to locate areas containing specific concentrations of the molecule. Measured by the swarm assay qualitatively and microfluidic techniques quantitatively, the characteristics of each “brake component” were identified and represented by a mathematical model. Furthermore, we established another mathematical model to anticipate the characteristics of the “brake component”. Based on this model, an abundant component library can be established to provide adequate component selection for different searching conditions without identifying all components individually. Finally, a systematic design procedure was proposed. Following this systematic procedure, one can design a genetic circuit for bacteria to rapidly search for and locate different concentrations of particular molecules by selecting the most adequate “brake component” in the library. Moreover, following simple procedures, one can also establish an exclusive component library suitable for other cultivated environments, promoter systems, or bacterial strains. PMID:27096615

Stochastic isotropic hyperelastic materials: constitutive calibration and model selection

NASA Astrophysics Data System (ADS)

Mihai, L. Angela; Woolley, Thomas E.; Goriely, Alain

2018-03-01

Biological and synthetic materials often exhibit intrinsic variability in their elastic responses under large strains, owing to microstructural inhomogeneity or when elastic data are extracted from viscoelastic mechanical tests. For these materials, although hyperelastic models calibrated to mean data are useful, stochastic representations accounting also for data dispersion carry extra information about the variability of material properties found in practical applications. We combine finite elasticity and information theories to construct homogeneous isotropic hyperelastic models with random field parameters calibrated to discrete mean values and standard deviations of either the stress-strain function or the nonlinear shear modulus, which is a function of the deformation, estimated from experimental tests. These quantities can take on different values, corresponding to possible outcomes of the experiments. As multiple models can be derived that adequately represent the observed phenomena, we apply Occam's razor by providing an explicit criterion for model selection based on Bayesian statistics. We then employ this criterion to select a model among competing models calibrated to experimental data for rubber and brain tissue under single or multiaxial loads.

Testing the ability of a semidistributed hydrological model to simulate contributing area

NASA Astrophysics Data System (ADS)

Mengistu, S. G.; Spence, C.

2016-06-01

A dry climate, the prevalence of small depressions, and the lack of a well-developed drainage network are characteristics of environments with extremely variable contributing areas to runoff. These types of regions arguably present the greatest challenge to properly understanding catchment streamflow generation processes. Previous studies have shown that contributing area dynamics are important for streamflow response, but the nature of the relationship between the two is not typically understood. Furthermore, it is not often tested how well hydrological models simulate contributing area. In this study, the ability of a semidistributed hydrological model, the PDMROF configuration of Environment Canada's MESH model, was tested to determine if it could simulate contributing area. The study focused on the St. Denis Creek watershed in central Saskatchewan, Canada, which with its considerable topographic depressions, exhibits wide variation in contributing area, making it ideal for this type of investigation. MESH-PDMROF was able to replicate contributing area derived independently from satellite imagery. Daily model simulations revealed a hysteretic relationship between contributing area and streamflow not apparent from the less frequent remote sensing observations. This exercise revealed that contributing area extent can be simulated by a semi-distributed hydrological model with a scheme that assumes storage capacity distribution can be represented with a probability function. However, further investigation is needed to determine if it can adequately represent the complex relationship between streamflow and contributing area that is such a key signature of catchment behavior.

Template-Based Modeling of Protein-RNA Interactions

PubMed Central

Zheng, Jinfang; Kundrotas, Petras J.; Vakser, Ilya A.

2016-01-01

Protein-RNA complexes formed by specific recognition between RNA and RNA-binding proteins play an important role in biological processes. More than a thousand of such proteins in human are curated and many novel RNA-binding proteins are to be discovered. Due to limitations of experimental approaches, computational techniques are needed for characterization of protein-RNA interactions. Although much progress has been made, adequate methodologies reliably providing atomic resolution structural details are still lacking. Although protein-RNA free docking approaches proved to be useful, in general, the template-based approaches provide higher quality of predictions. Templates are key to building a high quality model. Sequence/structure relationships were studied based on a representative set of binary protein-RNA complexes from PDB. Several approaches were tested for pairwise target/template alignment. The analysis revealed a transition point between random and correct binding modes. The results showed that structural alignment is better than sequence alignment in identifying good templates, suitable for generating protein-RNA complexes close to the native structure, and outperforms free docking, successfully predicting complexes where the free docking fails, including cases of significant conformational change upon binding. A template-based protein-RNA interaction modeling protocol PRIME was developed and benchmarked on a representative set of complexes. PMID:27662342

The Augmented Cognitive Mediation Model: Examining Antecedents of Factual and Structural Breast Cancer Knowledge Among Singaporean Women.

PubMed

Lee, Edmund W J; Shin, Mincheol; Kawaja, Ariffin; Ho, Shirley S

2016-05-01

As knowledge acquisition is an important component of health communication research, this study examines factors associated with Singaporean women's breast cancer knowledge using an augmented cognitive mediation model. We conducted a nationally representative study that surveyed 802 women between the ages of 30 and 70 using random-digit dialing. The results supported the augmented cognitive mediation model, which proposes the inclusion of risk perception as a motivator of health information seeking and structural knowledge as an additional knowledge dimension. There was adequate support for the hypothesized paths in the model. Risk perception was positively associated with attention to newspaper, television, Internet, and interpersonal communication. Attention to the three media channels was associated with interpersonal communication, but only newspaper and television attention were associated with elaboration. Interpersonal communication was positively associated with structural knowledge, whereas elaboration was associated with both factual and structural knowledge. Differential indirect effects between media attention and knowledge dimensions via interpersonal communication and elaboration were found. Theoretical and practical implications are discussed.

Pharmacokinetic/pharmacodynamic modeling of cardiac toxicity in human acute overdoses: utility and limitations.

PubMed

Mégarbane, Bruno; Aslani, Arsia Amir; Deye, Nicolas; Baud, Frédéric J

2008-05-01

Hypotension, cardiac failure, QT interval prolongation, dysrhythmias, and conduction disturbances are common complications of overdoses with cardiotoxicants. Pharmacokinetic/pharmacodynamic (PK/PD) relationships are useful to assess diagnosis, prognosis, and treatment efficacy in acute poisonings. To review the utility and limits of PK/PD studies of cardiac toxicity. Discussion of various models, mainly those obtained in digitalis, cyanide, venlafaxine and citalopram poisonings. A sigmoidal E(max) model appears adequate to represent the PK/PD relationships in cardiotoxic poisonings. PK/PD correlations investigate the discrepancies between the time course of the effect magnitude and its evolving concentrations. They may help in understanding the mechanisms of occurrence as well as disappearance of a cardiotoxic effect. When data are sparse, population-based PK/PD modeling using computer-intensive algorithms is helpful to estimate population mean values of PK parameters as well as their individual variability. Further PK/PD studies are needed in medical toxicology to allow understanding of the meaning of blood toxicant concentration in acute poisonings and thus improve management.

Simple Model for the Benzene Hexafluorobenzene Interaction

DOE PAGES

Tillack, Andreas F.; Robinson, Bruce H.

2017-06-05

While the experimental intermolecular distance distribution functions of pure benzene and pure hexafluorobenzene are well described by transferable all-atom force fields, the interaction between the two molecules (in a 1:1 mixture) is not well simulated. We demonstrate that the parameters of the transferable force fields are adequate to describe the intermolecular distance distribution if the charges are replaced by a set of charges that are not located at the atoms. Here, the simplest model that well describes the experimental distance distribution, between benzene and hexafluorobenzene, is that of a single ellipsoid for each molecule, representing the van der Waals interactions,more » and a set of three point charges (on the axis perpendicular to the arene plane) which give the same quadrupole moment as do the all atom charges from the transferable force fields.« less

HEAO A-2 observations of the X-ray spectra of the Centaurus and A1060 clusters of galaxies

NASA Technical Reports Server (NTRS)

Mitchell, R.; Mushotzky, R.

1980-01-01

X-ray spectral observations of two nearby low-luminosity clusters of galaxies are presented. For the Centaurus cluster an emission feature at 7.9 keV is detected at about one-third of the strength of the 6.7 keV line. This higher energy line represents K-beta emission from highly ionized iron. In addition, it is demonstrated that for neither the Centaurus nor the A1060 cluster can an isothermal model with an Fe emission line adequately fit the data. Instead, the simplest models which provide acceptable fits include a second, harder component which may be either a second exponential or a power law. The implications of the two-component nature of the continuum on the Fe abundance and the X-ray surface-brightness distribution are discussed.

Infrared spectra of rotating protostars

NASA Technical Reports Server (NTRS)

Adams, F. C.; Shu, F. H.

1986-01-01

Earlier calculations of the infrared emission expected from stars in the process of being made are corrected to include the most important observable effects of rotation and generalized. An improved version of the spherical model of a previous paper is developed, and the corresponding emergent spectral energy distributions are calculated for the theoretically expected mass infall rate in the cores of cool and quiescent molecular clouds. The dust grain opacity model and the temperature profile parameterization are improved. It is shown that the infrared spectrum of the IRAS source 04264+2426, which is associated with a Herbig-Haro object, can be adequately represented in terms of a rotating and accreting protostar. This strengthens the suggestion that collimated outflows in young stellar objects originate when a stellar wind tries to emerge and reverse the swirling pattern of infall which gave birth to the central star.

Origin of orbital debris impacts on LDEF's trailing surfaces

NASA Technical Reports Server (NTRS)

Kessler, Donald J.

1993-01-01

A model was developed to determine the origin of orbital impacts measured on the training surfaces of LDEF. The model calculates the expected debris impact crater distribution around LDEF as a function of debris orbital parameters. The results show that only highly elliptical, low inclination orbits could be responsible for these impacts. The most common objects left in this type of orbit are orbital transfer stages used by the U.S. and ESA to place payloads into geosynchronous orbit. Objects in this type of orbit are difficult to catalog by the U.S. Space Command; consequently there are independent reasons to believe that the catalog does not adequately represent this population. This analysis concludes that the relative number of cataloged objects with highly elliptical, low inclination orbits must be increased by a factor of 20 to be consistent with the LDEF data.

Simple Model for the Benzene Hexafluorobenzene Interaction

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

Tillack, Andreas F.; Robinson, Bruce H.

While the experimental intermolecular distance distribution functions of pure benzene and pure hexafluorobenzene are well described by transferable all-atom force fields, the interaction between the two molecules (in a 1:1 mixture) is not well simulated. We demonstrate that the parameters of the transferable force fields are adequate to describe the intermolecular distance distribution if the charges are replaced by a set of charges that are not located at the atoms. Here, the simplest model that well describes the experimental distance distribution, between benzene and hexafluorobenzene, is that of a single ellipsoid for each molecule, representing the van der Waals interactions,more » and a set of three point charges (on the axis perpendicular to the arene plane) which give the same quadrupole moment as do the all atom charges from the transferable force fields.« less

Age-Period-Cohort approaches to back-calculation of cancer incidence rate

PubMed Central

Oh, Cheongeun; Holford, Theodore R.

2016-01-01

A compartment model for cancer incidence and mortality is developed in which healthy subjects may develop cancer, and subsequently die of cancer or another cause. In order to adequately represent the experience of a defined population, it is also necessary to allow for subjects who are diagnosed at death, as well as subjects who migrate and are subsequently lost to follow-up. Expressions are derived for the number of cancer deaths as a function of the number of incidence cases and vice versa, which allows for the use of mortality statistics to obtain estimates of incidence using survival information. In addition, the model can be used to obtain estimates of cancer prevalence, which is useful for health care planning. The method is illustrated using data on lung cancer among males in Connecticut. PMID:25715831

Ecosystem Model Skill Assessment. Yes We Can!

PubMed Central

Olsen, Erik; Fay, Gavin; Gaichas, Sarah; Gamble, Robert; Lucey, Sean; Link, Jason S.

2016-01-01

Need to Assess the Skill of Ecosystem Models Accelerated changes to global ecosystems call for holistic and integrated analyses of past, present and future states under various pressures to adequately understand current and projected future system states. Ecosystem models can inform management of human activities in a complex and changing environment, but are these models reliable? Ensuring that models are reliable for addressing management questions requires evaluating their skill in representing real-world processes and dynamics. Skill has been evaluated for just a limited set of some biophysical models. A range of skill assessment methods have been reviewed but skill assessment of full marine ecosystem models has not yet been attempted. Northeast US Atlantis Marine Ecosystem Model We assessed the skill of the Northeast U.S. (NEUS) Atlantis marine ecosystem model by comparing 10-year model forecasts with observed data. Model forecast performance was compared to that obtained from a 40-year hindcast. Multiple metrics (average absolute error, root mean squared error, modeling efficiency, and Spearman rank correlation), and a suite of time-series (species biomass, fisheries landings, and ecosystem indicators) were used to adequately measure model skill. Overall, the NEUS model performed above average and thus better than expected for the key species that had been the focus of the model tuning. Model forecast skill was comparable to the hindcast skill, showing that model performance does not degenerate in a 10-year forecast mode, an important characteristic for an end-to-end ecosystem model to be useful for strategic management purposes. Skill Assessment Is Both Possible and Advisable We identify best-practice approaches for end-to-end ecosystem model skill assessment that would improve both operational use of other ecosystem models and future model development. We show that it is possible to not only assess the skill of a complicated marine ecosystem model, but that it is necessary do so to instill confidence in model results and encourage their use for strategic management. Our methods are applicable to any type of predictive model, and should be considered for use in fields outside ecology (e.g. economics, climate change, and risk assessment). PMID:26731540

Development of a Non-Invasive Biomonitoring Approach to Determine Exposure to the Organophosphorus Insecticide Chlorpyrifos in Rat Saliva

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

Timchalk, Chuck; Campbell, James A.; Liu, Guodong

2007-03-01

Abstract Non-invasive biomonitoring approaches are being developed using reliable portable analytical systems to quantify dosimetry utilizing readily obtainable body fluids, such as saliva. In the current study, rats were given single oral gavage doses (1, 10 or 50 mg/kg) of the insecticide chlorpyrifos (CPF), saliva and blood were collected from groups of animals (4/time-point) at 3, 6, and 12 hr post-dosing, and the samples were analyzed for the CPF metabolite trichlorpyridinol (TCP). Trichlorpyridinol was detected in both blood and saliva at all doses and the TCP concentration in blood exceeded saliva, although the kinetics in blood and saliva were comparable.more » A physiologically based pharmacokinetic and pharmacodynamic (PBPK/PD) model for CPF incorporated a compartment model to describe the time-course of TCP in blood and saliva. The model adequately simulated the experimental results over the dose ranges evaluated. A rapid and sensitive sequential injection (SI) electrochemical immunoassay was developed to monitor TCP, and the reported detection limit for TCP in water was 6 ng/L. Computer model simulation in the range of the Allowable Daily Intake (ADI) or Reference Dose (RfD) for CPF (0.01-0.003 mg/kg/day) suggest that the electrochemical immunoassay had adequate sensitivity to detect and quantify TCP in saliva at these low exposure levels. To validate this approach further studies are needed to more fully understand the pharmacokinetics of CPF and TCP excretion in saliva. The utilization of saliva as a biomonitoring matrix, coupled to real-time quantitation and PBPK/PD modeling represents a novel approach with broad application for evaluating both occupational and environmental exposures to insecticides.« less

Association of Sleep Adequacy With More Healthful Food Choices and Positive Workplace Experiences Among Motor Freight Workers

PubMed Central

Quintiliani, Lisa M.; Yang, May H.; Ebbeling, Cara B.; Stoddard, Anne M.; Pereira, Lesley K.; Sorensen, Glorian

2009-01-01

Objectives. We assessed whether adequate sleep is linked to more healthful eating behaviors among motor freight workers and whether it mediates the effects of workplace experiences. Methods. Data were derived from a baseline survey and assessment of permanent employees at 8 trucking terminals. Bivariate and multivariate regression models were used to examine relationships between work environment, sleep adequacy, and dietary choices. Results. The sample (n = 542) was 83% White, with a mean age of 49 years and a mean body mass index of 30 kg/m2. Most of the participants were satisfied with their job (87.5%) and reported adequate sleep (51%); 30% reported job strain. In our first model, lack of job strain and greater supervisor support were significantly associated with adequate sleep. In our second model, educational level, age, and adequate sleep were significantly associated with at least 2 of the 3 healthful eating choices assessed (P < .05). However, work experiences were not significant predictors of healthful food choices when adequate sleep was included. Conclusions. Adequate sleep is associated with more healthful food choices and may mediate the effects of workplace experiences. Thus, workplace health programs should be responsive to workers' sleep patterns. PMID:19890169

Modelling the impacts of pests and diseases on agricultural systems.

PubMed

Donatelli, M; Magarey, R D; Bregaglio, S; Willocquet, L; Whish, J P M; Savary, S

2017-07-01

The improvement and application of pest and disease models to analyse and predict yield losses including those due to climate change is still a challenge for the scientific community. Applied modelling of crop diseases and pests has mostly targeted the development of support capabilities to schedule scouting or pesticide applications. There is a need for research to both broaden the scope and evaluate the capabilities of pest and disease models. Key research questions not only involve the assessment of the potential effects of climate change on known pathosystems, but also on new pathogens which could alter the (still incompletely documented) impacts of pests and diseases on agricultural systems. Yield loss data collected in various current environments may no longer represent a adequate reference to develop tactical, decision-oriented, models for plant diseases and pests and their impacts, because of the ongoing changes in climate patterns. Process-based agricultural simulation modelling, on the other hand, appears to represent a viable methodology to estimate the impacts of these potential effects. A new generation of tools based on state-of-the-art knowledge and technologies is needed to allow systems analysis including key processes and their dynamics over appropriate suitable range of environmental variables. This paper offers a brief overview of the current state of development in coupling pest and disease models to crop models, and discusses technical and scientific challenges. We propose a five-stage roadmap to improve the simulation of the impacts caused by plant diseases and pests; i) improve the quality and availability of data for model inputs; ii) improve the quality and availability of data for model evaluation; iii) improve the integration with crop models; iv) improve the processes for model evaluation; and v) develop a community of plant pest and disease modelers.

Representing uncertainty in objective functions: extension to include the influence of serial correlation

NASA Astrophysics Data System (ADS)

Croke, B. F.

2008-12-01

The role of performance indicators is to give an accurate indication of the fit between a model and the system being modelled. As all measurements have an associated uncertainty (determining the significance that should be given to the measurement), performance indicators should take into account uncertainties in the observed quantities being modelled as well as in the model predictions (due to uncertainties in inputs, model parameters and model structure). In the presence of significant uncertainty in observed and modelled output of a system, failure to adequately account for variations in the uncertainties means that the objective function only gives a measure of how well the model fits the observations, not how well the model fits the system being modelled. Since in most cases, the interest lies in fitting the system response, it is vital that the objective function(s) be designed to account for these uncertainties. Most objective functions (e.g. those based on the sum of squared residuals) assume homoscedastic uncertainties. If model contribution to the variations in residuals can be ignored, then transformations (e.g. Box-Cox) can be used to remove (or at least significantly reduce) heteroscedasticity. An alternative which is more generally applicable is to explicitly represent the uncertainties in the observed and modelled values in the objective function. Previous work on this topic addressed the modifications to standard objective functions (Nash-Sutcliffe efficiency, RMSE, chi- squared, coefficient of determination) using the optimal weighted averaging approach. This paper extends this previous work; addressing the issue of serial correlation. A form for an objective function that includes serial correlation will be presented, and the impact on model fit discussed.

Alternative analytical forms to model diatomic systems based on the deformed exponential function.

PubMed

da Fonsêca, José Erinaldo; de Oliveira, Heibbe Cristhian B; da Cunha, Wiliam Ferreira; Gargano, Ricardo

2014-07-01

Using a deformed exponential function and the molecular-orbital theory for the simplest molecular ion, two new analytical functions are proposed to represent the potential energy of ground-state diatomic systems. The quality of these new forms was tested by fitting the ab initio electronic energies of the system LiH, LiNa, NaH, RbH, KH, H2, Li2, K2, H 2 (+) , BeH(+) and Li 2 (+) . From these fits, it was verified that these new proposals are able to adequately describe homonuclear, heteronuclear and cationic diatomic systems with good accuracy. Vibrational spectroscopic constant results obtained from these two proposals are in good agreement with experimental data.

Unveiling the mechanisms of dressed-photon-phonon etching based on hierarchical surface roughness measure

NASA Astrophysics Data System (ADS)

Naruse, Makoto; Yatsui, Takashi; Nomura, Wataru; Kawazoe, Tadashi; Aida, Masaki; Ohtsu, Motoichi

2013-02-01

Dressed-photon-phonon (DPP) etching is a disruptive technology in planarizing material surfaces because it completely eliminates mechanical contact processes. However, adequate metrics for evaluating the surface roughness and the underlying physical mechanisms are still not well understood. Here, we propose a two-dimensional hierarchical surface roughness measure, inspired by the Allan variance, that represents the effectiveness of DPP etching while conserving the original two-dimensional surface topology. Also, we build a simple physical model of DPP etching that agrees well with the experimental observations, which clearly shows the involvement of the intrinsic hierarchical properties of dressed photons, or optical near-fields, in the surface processing.

The status and challenge of global fire modelling

DOE PAGES

Hantson, Stijn; Arneth, Almut; Harrison, Sandy P.; ...

2016-06-09

Biomass burning impacts vegetation dynamics, biogeochemical cycling, atmospheric chemistry, and climate, with sometimes deleterious socio-economic impacts. Under future climate projections it is often expected that the risk of wildfires will increase. Our ability to predict the magnitude and geographic pattern of future fire impacts rests on our ability to model fire regimes, using either well-founded empirical relationships or process-based models with good predictive skill. While a large variety of models exist today, it is still unclear which type of model or degree of complexity is required to model fire adequately at regional to global scales. This is the central questionmore » underpinning the creation of the Fire Model Intercomparison Project (FireMIP), an international initiative to compare and evaluate existing global fire models against benchmark data sets for present-day and historical conditions. In this paper we review how fires have been represented in fire-enabled dynamic global vegetation models (DGVMs) and give an overview of the current state of the art in fire-regime modelling. In conclusion, we indicate which challenges still remain in global fire modelling and stress the need for a comprehensive model evaluation and outline what lessons may be learned from FireMIP.« less

The status and challenge of global fire modelling

NASA Astrophysics Data System (ADS)

Hantson, Stijn; Arneth, Almut; Harrison, Sandy P.; Kelley, Douglas I.; Prentice, I. Colin; Rabin, Sam S.; Archibald, Sally; Mouillot, Florent; Arnold, Steve R.; Artaxo, Paulo; Bachelet, Dominique; Ciais, Philippe; Forrest, Matthew; Friedlingstein, Pierre; Hickler, Thomas; Kaplan, Jed O.; Kloster, Silvia; Knorr, Wolfgang; Lasslop, Gitta; Li, Fang; Mangeon, Stephane; Melton, Joe R.; Meyn, Andrea; Sitch, Stephen; Spessa, Allan; van der Werf, Guido R.; Voulgarakis, Apostolos; Yue, Chao

2016-06-01

Biomass burning impacts vegetation dynamics, biogeochemical cycling, atmospheric chemistry, and climate, with sometimes deleterious socio-economic impacts. Under future climate projections it is often expected that the risk of wildfires will increase. Our ability to predict the magnitude and geographic pattern of future fire impacts rests on our ability to model fire regimes, using either well-founded empirical relationships or process-based models with good predictive skill. While a large variety of models exist today, it is still unclear which type of model or degree of complexity is required to model fire adequately at regional to global scales. This is the central question underpinning the creation of the Fire Model Intercomparison Project (FireMIP), an international initiative to compare and evaluate existing global fire models against benchmark data sets for present-day and historical conditions. In this paper we review how fires have been represented in fire-enabled dynamic global vegetation models (DGVMs) and give an overview of the current state of the art in fire-regime modelling. We indicate which challenges still remain in global fire modelling and stress the need for a comprehensive model evaluation and outline what lessons may be learned from FireMIP.

The status and challenge of global fire modelling

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

Hantson, Stijn; Arneth, Almut; Harrison, Sandy P.

Biomass burning impacts vegetation dynamics, biogeochemical cycling, atmospheric chemistry, and climate, with sometimes deleterious socio-economic impacts. Under future climate projections it is often expected that the risk of wildfires will increase. Our ability to predict the magnitude and geographic pattern of future fire impacts rests on our ability to model fire regimes, using either well-founded empirical relationships or process-based models with good predictive skill. While a large variety of models exist today, it is still unclear which type of model or degree of complexity is required to model fire adequately at regional to global scales. This is the central questionmore » underpinning the creation of the Fire Model Intercomparison Project (FireMIP), an international initiative to compare and evaluate existing global fire models against benchmark data sets for present-day and historical conditions. In this paper we review how fires have been represented in fire-enabled dynamic global vegetation models (DGVMs) and give an overview of the current state of the art in fire-regime modelling. In conclusion, we indicate which challenges still remain in global fire modelling and stress the need for a comprehensive model evaluation and outline what lessons may be learned from FireMIP.« less

Modeling Elevation and Aspect Controls on Emerging Ecohydrologic Processes and Ecosystem Patterns Using the Component-based Landlab Framework

NASA Astrophysics Data System (ADS)

Nudurupati, S. S.; Istanbulluoglu, E.; Adams, J. M.; Hobley, D. E. J.; Gasparini, N. M.; Tucker, G. E.; Hutton, E. W. H.

2014-12-01

Topography plays a commanding role on the organization of ecohydrologic processes and resulting vegetation patterns. In southwestern United States, climate conditions lead to terrain aspect- and elevation-controlled ecosystems, with mesic north-facing and xeric south-facing vegetation types; and changes in biodiversity as a function of elevation from shrublands in low desert elevations, to mixed grass/shrublands in mid elevations, and forests at high elevations and ridge tops. These observed patterns have been attributed to differences in topography-mediated local soil moisture availability, micro-climatology, and life history processes of plants that control chances of plant establishment and survival. While ecohydrologic models represent local vegetation dynamics in sufficient detail up to sub-hourly time scales, plant life history and competition for space and resources has not been adequately represented in models. In this study we develop an ecohydrologic cellular automata model within the Landlab component-based modeling framework. This model couples local vegetation dynamics (biomass production, death) and plant establishment and competition processes for resources and space. This model is used to study the vegetation organization in a semiarid New Mexico catchment where elevation and hillslope aspect play a defining role on plant types. Processes that lead to observed plant types across the landscape are examined by initializing the domain with randomly assigned plant types and systematically changing model parameters that couple plant response with soil moisture dynamics. Climate perturbation experiments are conducted to examine the plant response in space and time. Understanding the inherently transient ecohydrologic systems is critical to improve predictions of climate change impacts on ecosystems.

Statistical Compression of Wind Speed Data

NASA Astrophysics Data System (ADS)

Tagle, F.; Castruccio, S.; Crippa, P.; Genton, M.

2017-12-01

In this work we introduce a lossy compression approach that utilizes a stochastic wind generator based on a non-Gaussian distribution to reproduce the internal climate variability of daily wind speed as represented by the CESM Large Ensemble over Saudi Arabia. Stochastic wind generators, and stochastic weather generators more generally, are statistical models that aim to match certain statistical properties of the data on which they are trained. They have been used extensively in applications ranging from agricultural models to climate impact studies. In this novel context, the parameters of the fitted model can be interpreted as encoding the information contained in the original uncompressed data. The statistical model is fit to only 3 of the 30 ensemble members and it adequately captures the variability of the ensemble in terms of seasonal internannual variability of daily wind speed. To deal with such a large spatial domain, it is partitioned into 9 region, and the model is fit independently to each of these. We further discuss a recent refinement of the model, which relaxes this assumption of regional independence, by introducing a large-scale component that interacts with the fine-scale regional effects.

HDRK-Man: a whole-body voxel model based on high-resolution color slice images of a Korean adult male cadaver

NASA Astrophysics Data System (ADS)

Kim, Chan Hyeong; Hyoun Choi, Sang; Jeong, Jong Hwi; Lee, Choonsik; Chung, Min Suk

2008-08-01

A Korean voxel model, named 'High-Definition Reference Korean-Man (HDRK-Man)', was constructed using high-resolution color photographic images that were obtained by serially sectioning the cadaver of a 33-year-old Korean adult male. The body height and weight, the skeletal mass and the dimensions of the individual organs and tissues were adjusted to the reference Korean data. The resulting model was then implemented into a Monte Carlo particle transport code, MCNPX, to calculate the dose conversion coefficients for the internal organs and tissues. The calculated values, overall, were reasonable in comparison with the values from other adult voxel models. HDRK-Man showed higher dose conversion coefficients than other models, due to the facts that HDRK-Man has a smaller torso and that the arms of HDRK-Man are shifted backward. The developed model is believed to adequately represent average Korean radiation workers and thus can be used for more accurate calculation of dose conversion coefficients for Korean radiation workers in the future.

CRCM + BATS-R-US two-way coupling

NASA Astrophysics Data System (ADS)

Glocer, A.; Fok, M.; Meng, X.; Toth, G.; Buzulukova, N.; Chen, S.; Lin, K.

2013-04-01

We present the coupling methodology and validation of a fully coupled inner and global magnetosphere code using the infrastructure provided by the Space Weather Modeling Framework (SWMF). In this model, the Comprehensive Ring Current Model (CRCM) represents the inner magnetosphere, while the Block-Adaptive-Tree Solar-Wind Roe-Type Upwind Scheme (BATS-R-US) represents the global magnetosphere. The combined model is a global magnetospheric code with a realistic ring current and consistent electric and magnetic fields. The computational performance of the model was improved to surpass real-time execution by the use of the Message Passing Interface (MPI) to parallelize the CRCM. Initial simulations under steady driving found that the coupled model resulted in a higher pressure in the inner magnetosphere and an inflated closed field-line region as compared to simulations without inner-magnetosphere coupling. Our validation effort was split into two studies. The first study examined the ability of the model to reproduce Dst for a range of events from the Geospace Environment Modeling (GEM) Dst Challenge. It also investigated the possibility of a baseline shift and compared two approaches to calculating Dst from the model. We found that the model did a reasonable job predicting Dst and Sym-H according to our two metrics of prediction efficiency and predicted yield. The second study focused on the specific case of the 22 July 2009 moderate geomagnetic storm. In this study, we directly compare model predictions and observations for Dst, THEMIS energy spectragrams, TWINS ENA images, and GOES 11 and 12 magnetometer data. The model did an adequate job reproducing trends in the data. Moreover, we found that composition can have a large effect on the result.

Energy awareness for supercapacitors using Kalman filter state-of-charge tracking

NASA Astrophysics Data System (ADS)

Nadeau, Andrew; Hassanalieragh, Moeen; Sharma, Gaurav; Soyata, Tolga

2015-11-01

Among energy buffering alternatives, supercapacitors can provide unmatched efficiency and durability. Additionally, the direct relation between a supercapacitor's terminal voltage and stored energy can improve energy awareness. However, a simple capacitive approximation cannot adequately represent the stored energy in a supercapacitor. It is shown that the three branch equivalent circuit model provides more accurate energy awareness. This equivalent circuit uses three capacitances and associated resistances to represent the supercapacitor's internal SOC (state-of-charge). However, the SOC cannot be determined from one observation of the terminal voltage, and must be tracked over time using inexact measurements. We present: 1) a Kalman filtering solution for tracking the SOC; 2) an on-line system identification procedure to efficiently estimate the equivalent circuit's parameters; and 3) experimental validation of both parameter estimation and SOC tracking for 5 F, 10 F, 50 F, and 350 F supercapacitors. Validation is done within the operating range of a solar powered application and the associated power variability due to energy harvesting. The proposed techniques are benchmarked against the simple capacitive model and prior parameter estimation techniques, and provide a 67% reduction in root-mean-square error for predicting usable buffered energy.

Smart active pilot-in-the-loop systems

NASA Astrophysics Data System (ADS)

Thomas, Segun

1995-04-01

Representation of on-orbit microgravity environment in a 1-g environment is a continuing problem in space engineering analysis, procedures development and crew training. A way of adequately depicting weightlessness in the performance of on-orbit tasks is by a realistic (or real-time) computer based representation that provides the look, touch, and feel of on-orbit operation. This paper describes how a facility, the Systems Engineering Simulator at the Johnson Space Center, is utilizing recent advances in computer processing power and multi- processing capability to intelligently represent all systems, sub-systems and environmental elements associated with space flight operations. It first describes the computer hardware and interconnection between processors; the computer software responsible for task scheduling, health monitoring, sub-system and environment representation; control room and crew station. It then describes, the mathematical models that represent the dynamics of contact between the Mir and the Space Shuttle during the upcoming US and Russian Shuttle/Mir space mission. Results are presented comparing the response of the smart, active pilot-in-the-loop system to non-time critical CRAY model. A final example of how these systems are utilized is given in the development that supported the highly successful Hubble Space Telescope repair mission.

Conscientiousness and obsessive-compulsive personality disorder.

PubMed

Samuel, Douglas B; Widiger, Thomas A

2011-07-01

A dimensional perspective on personality disorder hypothesizes that the current diagnostic categories represent maladaptive variants of general personality traits. However, a fundamental foundation of this viewpoint is that dimensional models can adequately account for the pathology currently described by these categories. While most of the personality disorders have well established links to dimensional models that buttress this hypothesis, obsessive-compulsive personality disorder (OCPD) has obtained only inconsistent support. The current study administered multiple measures of 1) conscientiousness-related personality traits, 2) DSM-IV OCPD, and 3) specific components of OCPD (e.g., compulsivity and perfectionism) to a sample of 536 undergraduates who were oversampled for elevated OCPD scores. Six existing measures of conscientiousness-related personality traits converged strongly with each other supporting their assessment of a common trait. These measures of conscientiousness correlated highly with scales assessing specific components of OCPD, but obtained variable relationships with measures of DSM-IV OCPD. More specifically, there were differences within the conscientiousness instruments such that those designed to assess general personality functioning had small to medium relationships with OCPD, but those assessing more maladaptive variants obtained large effect sizes. These findings support the view that OCPD does represent a maladaptive variant of normal-range conscientiousness.

Pinus taeda forest growth predictions in the 21st century vary with site mean annual temperature and site quality.

PubMed

Gonzalez-Benecke, Carlos A; Teskey, Robert O; Dinon-Aldridge, Heather; Martin, Timothy A

2017-11-01

Climate projections from 20 downscaled global climate models (GCMs) were used with the 3-PG model to predict the future productivity and water use of planted loblolly pine (Pinus taeda) growing across the southeastern United States. Predictions were made using Representative Concentration Pathways (RCP) 4.5 and 8.5. These represent scenarios in which total radiative forcing stabilizes before 2100 (RCP 4.5) or continues increasing throughout the century (RCP 8.5). Thirty-six sites evenly distributed across the native range of the species were used in the analysis. These sites represent a range in current mean annual temperature (14.9-21.6°C) and precipitation (1,120-1,680 mm/year). The site index of each site, which is a measure of growth potential, was varied to represent different levels of management. The 3-PG model predicted that aboveground biomass growth and net primary productivity will increase by 10%-40% in many parts of the region in the future. At cooler sites, the relative growth increase was greater than at warmer sites. By running the model with the baseline [CO 2 ] or the anticipated elevated [CO 2 ], the effect of CO 2 on growth was separated from that of other climate factors. The growth increase at warmer sites was due almost entirely to elevated [CO 2 ]. The growth increase at cooler sites was due to a combination of elevated [CO 2 ] and increased air temperature. Low site index stands had a greater relative increase in growth under the climate change scenarios than those with a high site index. Water use increased in proportion to increases in leaf area and productivity but precipitation was still adequate, based on the downscaled GCM climate projections. We conclude that an increase in productivity can be expected for a large majority of the planted loblolly pine stands in the southeastern United States during this century. © 2017 John Wiley & Sons Ltd.

Montana rest area plan

DOT National Transportation Integrated Search

1999-12-01

Montana first developed a rest area plan in 1985; however, that plan no longer adequately sported decisions related to longe-range policy issues. Hence this docment represents a comprehensive effort to update rest area planning for Montana. A three p...

Gaussian membership functions are most adequate in representing uncertainty in measurements

NASA Technical Reports Server (NTRS)

Kreinovich, V.; Quintana, C.; Reznik, L.

1992-01-01

In rare situations, like fundamental physics, we perform experiments without knowing what their results will be. In the majority of real-life measurement situations, we more or less know beforehand what kind of results we will get. Of course, this is not the precise knowledge of the type 'the result will be between alpha - beta and alpha + beta,' because in this case, we would not need any measurements at all. This is usually a knowledge that is best represented in uncertain terms, like 'perhaps (or 'most likely', etc.) the measured value x is between alpha - beta and alpha + beta.' Traditional statistical methods neglect this additional knowledge and process only the measurement results. So it is desirable to be able to process this uncertain knowledge as well. A natural way to process it is by using fuzzy logic. But, there is a problem; we can use different membership functions to represent the same uncertain statements, and different functions lead to different results. What membership function do we choose? In the present paper, we show that under some reasonable assumptions, Gaussian functions mu(x) = exp(-beta(x(exp 2))) are the most adequate choice of the membership functions for representing uncertainty in measurements. This representation was efficiently used in testing jet engines to airplanes and spaceships.

Blind Biobanking of the Prostatectomy Specimen: Critical Evaluation of the Existing Techniques and Development of the New 4-Level Tissue Extraction Model With High Sampling Efficacy.

PubMed

Tolkach, Yuri; Eminaga, Okyaz; Wötzel, Fabian; Huss, Sebastian; Bettendorf, Olaf; Eltze, Elke; Abbas, Mahmoud; Imkamp, Florian; Semjonow, Axel

2017-03-01

Fresh tissue is mandatory to perform high-quality translation studies. Several models for tissue extraction from prostatectomy specimens without guidance by frozen sections are already introduced. However, little is known about the sampling efficacy of these models, which should provide representative tissue in adequate volumes, account for multifocality and heterogeneity of tumor, not violate the routine final pathological examination, and perform quickly without frozen section-based histological control. The aim of the study was to evaluate the sampling efficacy of the existing tissue extraction models without guidance by frozen sections ("blind") and to develop an optimized model for tissue extraction. Five hundred thirty-three electronic maps of the tumor distribution in prostates from a single-center cohort of the patients subjected to radical prostatectomy were used for analysis. Six available models were evaluated in silico for their sampling efficacy. Additionally, a novel model achieving the best sampling efficacy was developed. The available models showed high efficacies for sampling "any part" from the tumor (up to 100%), but were uniformly low in efficacy to sample all tumor foci from the specimens (with the best technique sampling only 51.6% of the all tumor foci). The novel 4-level extraction model achieved a sampling efficacy of 93.1% for all tumor foci. The existing "blind" tissue extraction models from prostatectomy specimens without frozen sections control are suitable to target tumor tissues but these tissues do not represent the whole tumor. The novel 4-level model provides the highest sampling efficacy and a promising potential for integration into routine. Prostate 77: 396-405, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Teachers' self-assessed levels of preparation

NASA Astrophysics Data System (ADS)

White, Susan C.

2016-02-01

Every four years we survey a nationally representative sample of high school physics teachers. We define anyone who teaches at least one physics class to be a "physics teacher." About 40% of these teachers teach a majority of their classes in subjects other than physics. We also ask teachers to rate how well prepared they felt in various aspects of teaching. The response choices are "not adequately prepared," "adequately prepared," and "very well prepared." The accompanying figure shows the proportion of teachers who reported feeling adequately or very well prepared in the following aspects of teaching: • Basic physics knowledge, • Other science knowledge, • Application of physics to everyday experience, • Use of demonstrations, • Instructional laboratory design, • Use of computers in physics instruction and labs, and • Recent developments in physics.

Assessment of seismic design response factors of concrete wall buildings

NASA Astrophysics Data System (ADS)

Mwafy, Aman

2011-03-01

To verify the seismic design response factors of high-rise buildings, five reference structures, varying in height from 20- to 60-stories, were selected and designed according to modern design codes to represent a wide range of concrete wall structures. Verified fiber-based analytical models for inelastic simulation were developed, considering the geometric nonlinearity and material inelasticity of the structural members. The ground motion uncertainty was accounted for by employing 20 earthquake records representing two seismic scenarios, consistent with the latest understanding of the tectonic setting and seismicity of the selected reference region (UAE). A large number of Inelastic Pushover Analyses (IPAs) and Incremental Dynamic Collapse Analyses (IDCAs) were deployed for the reference structures to estimate the seismic design response factors. It is concluded that the factors adopted by the design code are adequately conservative. The results of this systematic assessment of seismic design response factors apply to a wide variety of contemporary concrete wall buildings with various characteristics.

Kinetics of the Reactions of Cl((sup 2)P(sub J)) and Br((sup 2)P(sub 3/2)) with O3

NASA Technical Reports Server (NTRS)

Nicovich, J. M.; Kreutter, K. D.; Wine, P. H.

1997-01-01

A laser flash photolysis-resonance fluorescence technique has been employed to study the kinetics of the important stratospheric reactions Cl((sup 2)P(sub J)) + O3 yields ClO + O2 and Br((sup 2)P(sub 3/2)) + O3 yields BrO + O2 as a function of temperature. The temperature dependence observed for the Cl((sup 2)P(sub J)) + O3 reaction is nonArrhenius, but can be adequately described by the following two Arrhenius expressions (units are cu cm/(molecule.s), errors are 2 sigma and represent precision only): k(sub 1)(T) = (1.19 +/- 0.21) x 10(exp -11) exp[(-33 +/- 37)/T] for T = 189-269 K and k(sub 1)(T) = (2.49 +/- 0.38) x 10(exp -11) exp[(-233 +/- 46)/T] for 269-385 K. At temperatures below 230 K, the rate coefficients determined in this study are faster than any reported previously. Incorporation of our values for k(sub 1)(T) into stratospheric models would increase calculated ClO levels and decrease calculated HCI levels; hence the calculated efficiency of ClO catalyzed ozone destruction would increase. The temperature dependence observed for the Br((sup 2)P(sub 3/2)) + O3 reaction is adequately described by the following Arrhenius expression (units are cu cm/(molecule.s), errors are 2 sigma and represent precision only): k(sub 2)(T) = (1.50 +/- 0.16) x 10(exp -11)exp[(-775 +/- 30)/T for 195-392 K. While not in quantitative agreement with Arrhenius parameters reported in most previous studies, our results almost exactly reproduce the average of all earlier studies and therefore will not affect the choice of k(sub 2)(T) for use in modeling stratospheric BrO2 chemistry.

8 CFR 214.4 - Denial of certification, denial of recertification or withdrawal of SEVP certification.

Code of Federal Regulations, 2011 CFR

2011-01-01

...). (xii) Failure to operate as a bona fide institution of learning. (xiii) Failure to employ adequate...) Failure to maintain the physical plant, curriculum, and teaching staff in the manner represented in the...

Real-time measurement of quality during the compaction of subgrade soils.

DOT National Transportation Integrated Search

2012-12-01

Conventional quality control of subgrade soils during their compaction is usually performed by monitoring moisture content and dry density at a few discrete locations. However, randomly selected points do not adequately represent the entire compacted...

Fluor Daniel Hanford contract standards/requirements identification document

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

Bennett, G.L.

1997-04-24

This document, the Standards/Requirements Identification Document (S/RID) for the Fluor Daniel Hanford Contract, represents the necessary and sufficient requirements to provide an adequate level of protection of the worker, public health and safety, and the environment.

Construction of a model demonstrating neural pathways and reflex arcs.

PubMed

Chan, V; Pisegna, J M; Rosian, R L; DiCarlo, S E

1996-12-01

Employment opportunities in the future will require higher skills and an understanding of mathematics and science. As a result of the growing number of careers that require solid science and mathematics training, the methods of science education are undergoing major reform. To adequately equip students for technologically advanced positions, new teaching methods must be developed that prepare tomorrow's workforce for the challenges of the 21st century. One such method is the use of models. By actively building and manipulating concrete models that represent scientific concepts, students are involved in the most basic level of Piaget's learning scheme: the sensorimotor stage. Models are useful in reaching all students at the foundational levels of learning, and further learning experiences are rapidly moved through higher learning levels. This success ensures greater comprehension and understanding compared with the traditional methods of rote memorization. We developed an exercise for the construction of an inexpensive, easy-to-build model demonstrating neural pathways and reflex arcs. Our exercise also includes many supplemental teaching tools. The exercise is designed to fulfill the need of sound physiological teaching materials for high school students.

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

Zhang, Na; Zhang, Peng; Kang, Wei

Multiscale simulations of fluids such as blood represent a major computational challenge of coupling the disparate spatiotemporal scales between molecular and macroscopic transport phenomena characterizing such complex fluids. In this paper, a coarse-grained (CG) particle model is developed for simulating blood flow by modifying the Morse potential, traditionally used in Molecular Dynamics for modeling vibrating structures. The modified Morse potential is parameterized with effective mass scales for reproducing blood viscous flow properties, including density, pressure, viscosity, compressibility and characteristic flow dynamics of human blood plasma fluid. The parameterization follows a standard inverse-problem approach in which the optimal micro parameters aremore » systematically searched, by gradually decoupling loosely correlated parameter spaces, to match the macro physical quantities of viscous blood flow. The predictions of this particle based multiscale model compare favorably to classic viscous flow solutions such as Counter-Poiseuille and Couette flows. It demonstrates that such coarse grained particle model can be applied to replicate the dynamics of viscous blood flow, with the advantage of bridging the gap between macroscopic flow scales and the cellular scales characterizing blood flow that continuum based models fail to handle adequately.« less

Prospects for Alpha Particle Heating in JET in the Hot Ion Regime

NASA Astrophysics Data System (ADS)

Cordey, J. G.; Keilhacker, M.; Watkins, M. L.

1987-01-01

The prospects for alpha particle heating in JET are discussed. A computational model is developed to represent adequately the neutron yield from JET plasmas heated by neutral beam injection. This neutral beam model, augmented by a simple plasma model, is then used to determine the neutron yields and fusion Q-values anticipated for different heating schemes in future operation of JET with tritium. The relative importance of beam-thermal and thermal-thermal reactions is pointed out and the dependence of the results on, for example, plasma density, temperature, energy confinement and purity is shown. Full 1½-D transport code calculations, based on models developed for ohmic, ICRF and NBI heated JET discharges, are used also to provide a power scan for JET operation in tritium in the low density, high ion temperature regime. The results are shown to be in good agreement with the estimates made using the simple plasma model and indicate that, based on present knowledge, a fusion Q-value in the plasma centre above unity should be achieved in JET.

Knowledge representation and qualitative simulation of salmon redd functioning. Part II: qualitative model of redds.

PubMed

Guerrin, F; Dumas, J

2001-02-01

This paper describes a qualitative model of the functioning of salmon redds (spawning areas of salmon) and its impact on mortality rates of early stages. For this, we use Qsim, a qualitative simulator, which appeared adequate for representing available qualitative knowledge of freshwater ecology experts (see Part I of this paper). Since the number of relevant variables was relatively large, it appeared necessary to decompose the model into two parts, corresponding to processes occurring at separate time-scales. A qualitative clock allows us to submit the simulation of salmon developmental stages to the calculation of accumulated daily temperatures (degree-days), according to the clock ticks and a water temperature regime set by the user. Therefore, this introduces some way of real-time dating and duration in a purely qualitative model. Simulating both sub-models, either separately or by means of alternate transitions, allows us to generate the evolutions of variables of interest, such as the mortality rates according to two factors (flow of oxygenated water and plugging of gravel interstices near the bed surface), under various scenarios.

Virtual guidance as a tool to obtain diagnostic ultrasound for spaceflight and remote environments.

PubMed

Martin, David S; Caine, Timothy L; Matz, Timothy; Lee, Stuart M C; Stenger, Michael B; Sargsyan, Ashot E; Platts, Steven H

2012-10-01

With missions planned to travel greater distances from Earth at ranges that make real-time two-way communication impractical, astronauts will be required to perform autonomous medical diagnostic procedures during future exploration missions. Virtual guidance is a form of just-in-time training developed to allow novice ultrasound operators to acquire diagnostically-adequate images of clinically relevant anatomical structures using a prerecorded audio/visual tutorial viewed in real-time. Individuals without previous experience in ultrasound were recruited to perform carotid artery (N = 10) and ophthalmic (N = 9) ultrasound examinations using virtual guidance as their only training tool. In the carotid group, each untrained operator acquired two-dimensional, pulsed and color Doppler of the carotid artery. In the ophthalmic group, operators acquired representative images of the anterior chamber of the eye, retina, optic nerve, and nerve sheath. Ultrasound image quality was evaluated by independent imaging experts. Of the studies, 8 of the 10 carotid and 17 of 18 of the ophthalmic images (2 images collected per study) were judged to be diagnostically adequate. The quality of all but one of the ophthalmic images ranged from adequate to excellent. Diagnostically-adequate carotid and ophthalmic ultrasound examinations can be obtained by previously untrained operators with assistance from only an audio/video tutorial viewed in real time while scanning. This form of just-in-time training, which can be applied to other examinations, represents an opportunity to acquire important information for NASA flight surgeons and researchers when trained medical personnel are not available or when remote guidance is impractical.

76 FR 53162 - Acceptance of Public Submissions Regarding the Study of Stable Value Contracts

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-25

... the risk of a run on a SVF? To the extent that SVC providers use value-at-risk (``VaR'') models, do such VaR models adequately assess the risk of loss resulting from such events or other possible but extremely unlikely events? Do other loss models more adequately assess the risk of loss, such as the...

Different enzyme kinetic models.

PubMed

Seibert, Eleanore; Tracy, Timothy S

2014-01-01

As described in Chapter 2 , a large number of enzymatic reactions can be adequately described by Michaelis-Menten kinetics. The Michaelis-Menten equation represents a rectangular hyperbola, with a y-asymptote at the V max value. In many cases, more complex kinetic models are required to explain the observed data. Atypical kinetic profiles are believed to arise from the simultaneous binding of multiple molecules within the active site of the enzyme (Tracy and Hummel, Drug Metab Rev 36:231-242, 2004). Several cytochromes P450 have large active sites that enable binding of multiple molecules (Wester et al. J Biol Chem 279:35630-35637, 2004; Yano et al. J Biol Chem 279:38091-38094, 2004). Thus, atypical kinetics are not uncommon in in vitro drug metabolism studies. This chapter covers enzyme kinetic reactions in which a single enzyme has multiple binding sites for substrates and/or inhibitors as well as reactions catalyzed by multiple enzymes.

Design and development of a cross-cultural disposition inventory

NASA Astrophysics Data System (ADS)

Davies, Randall; Zaugg, Holt; Tateishi, Isaku

2015-01-01

Advances in technology have increased the likelihood that engineers will have to work in a global, culturally diverse setting. Many schools of engineering are currently revising their curricula to help students to develop cultural competence. However, our ability to measure cultural dispositions can be a challenge. The purpose of this project was to develop and test an instrument that measures the various aspects of cultural disposition. The results of the validation process verified that the hypothesised model adequately represented the data. The refined instrument produced a four-factor model for the overall construct. The validation process for the instrument verified the existence of specific subcomponents that form the overall cultural disposition construct. There also seems to be a hierarchical relationship within the subcomponents of cultural disposition. Additional research is needed to explore which aspects of cultural disposition affect an individual's ability to work effectively in a culturally diverse engineering team.

Calorie restriction and cardiometabolic health.

PubMed

Fontana, Luigi

2008-02-01

An epidemic of overweight/obesity and type 2 diabetes, caused by overeating nutrient-poor energy-dense foods and a sedentary lifestyle, is spreading rapidly throughout the world. Abdominal obesity represents a serious threat to health because it increases the risk of developing many chronic diseases, including cardiovascular disease and cancer. Calorie restriction (CR) with adequate nutrition improves cardiometabolic health, prevents tumorigenesis and increases life span in experimental animals. The purpose of this review is to evaluate the metabolic and clinical implications of CR with adequate nutrition in humans, within the context of data obtained in animal models. It is unlikely that information regarding the effect of CR on maximal life span in humans will become available in the foreseeable future. In young and middle-aged healthy individuals, however, CR causes many of the same cardiometabolic adaptations that occur in long-lived CR rodents, including decreased metabolic, hormonal and inflammatory risk factors for diabetes, hypertension, cardiovascular disease and cancer. Unraveling the mechanisms that link calorie intake and body composition with metabolism and aging will be a major step in understanding the age-dependency of a wide range of human diseases and will also contribute to improve the general quality of life at old ages.

A spatiotemporal data model for incorporating time in geographic information systems (GEN-STGIS)

NASA Astrophysics Data System (ADS)

Narciso, Flor Eugenia

Temporal Geographic Information Systems (TGIS) is a new technology, which is being developed to work with Geographic Information Systems (GIS) that deal with geographic phenomena that change over time. The capabilities of TGIS depend on the underlying data model. However, a literature review of current spatiotemporal GIS data models has shown that they are not adequate for managing time when representing temporal data. In addition, the majority of these data models have been designed to support the requirements of specific-purpose applications. In an effort to resolve this problem, the related literature has been explored. A comparative investigation of the current spatiotemporal GIS data models has been made to identify their characteristics, advantages and disadvantages, similarities and differences, and to determine why they do not work adequately. A new object-oriented General-purpose Spatiotemporal GIS (GEN-STGIS) data model is proposed here. This model provides better representation, storage and management of data related to geographic phenomena that change over time and overcomes some of the problems detected in the reviewed data models. The proposed data model has four key benefits. First, it provides the capabilities of a standard vector-based GIS embedded in the 2-D Euclidean space. Second, it includes the two temporal dimensions, valid time and transaction time, supported by temporal databases. Third, it inherits, from the object oriented approach, the flexibility, modularity and ability to handle the complexities introduced by spatial and temporal dimensions. Fourth, it improves the geographic query capabilities of current TGIS with the introduction of the concept of bounding box while providing temporal and spatiotemporal query capabilities. The data model is then evaluated in order to assess its strengths and weaknesses as a spatiotemporal GIS data model, and to determine how well the model satisfies the requirements imposed by TGIS applications. The practicality of the data model is demonstrated by the creation of a TGIS example and the partial implementation of the model using the POET Java software for developing the object-oriented database. the object-oriented database.

A systems approach to college drinking: development of a deterministic model for testing alcohol control policies.

PubMed

Scribner, Richard; Ackleh, Azmy S; Fitzpatrick, Ben G; Jacquez, Geoffrey; Thibodeaux, Jeremy J; Rommel, Robert; Simonsen, Neal

2009-09-01

The misuse and abuse of alcohol among college students remain persistent problems. Using a systems approach to understand the dynamics of student drinking behavior and thus forecasting the impact of campus policy to address the problem represents a novel approach. Toward this end, the successful development of a predictive mathematical model of college drinking would represent a significant advance for prevention efforts. A deterministic, compartmental model of college drinking was developed, incorporating three processes: (1) individual factors, (2) social interactions, and (3) social norms. The model quantifies these processes in terms of the movement of students between drinking compartments characterized by five styles of college drinking: abstainers, light drinkers, moderate drinkers, problem drinkers, and heavy episodic drinkers. Predictions from the model were first compared with actual campus-level data and then used to predict the effects of several simulated interventions to address heavy episodic drinking. First, the model provides a reasonable fit of actual drinking styles of students attending Social Norms Marketing Research Project campuses varying by "wetness" and by drinking styles of matriculating students. Second, the model predicts that a combination of simulated interventions targeting heavy episodic drinkers at a moderately "dry" campus would extinguish heavy episodic drinkers, replacing them with light and moderate drinkers. Instituting the same combination of simulated interventions at a moderately "wet" campus would result in only a moderate reduction in heavy episodic drinkers (i.e., 50% to 35%). A simple, five-state compartmental model adequately predicted the actual drinking patterns of students from a variety of campuses surveyed in the Social Norms Marketing Research Project study. The model predicted the impact on drinking patterns of several simulated interventions to address heavy episodic drinking on various types of campuses.

A Systems Approach to College Drinking: Development of a Deterministic Model for Testing Alcohol Control Policies*

PubMed Central

Scribner, Richard; Ackleh, Azmy S.; Fitzpatrick, Ben G.; Jacquez, Geoffrey; Thibodeaux, Jeremy J.; Rommel, Robert; Simonsen, Neal

2009-01-01

Objective: The misuse and abuse of alcohol among college students remain persistent problems. Using a systems approach to understand the dynamics of student drinking behavior and thus forecasting the impact of campus policy to address the problem represents a novel approach. Toward this end, the successful development of a predictive mathematical model of college drinking would represent a significant advance for prevention efforts. Method: A deterministic, compartmental model of college drinking was developed, incorporating three processes: (1) individual factors, (2) social interactions, and (3) social norms. The model quantifies these processes in terms of the movement of students between drinking compartments characterized by five styles of college drinking: abstainers, light drinkers, moderate drinkers, problem drinkers, and heavy episodic drinkers. Predictions from the model were first compared with actual campus-level data and then used to predict the effects of several simulated interventions to address heavy episodic drinking. Results: First, the model provides a reasonable fit of actual drinking styles of students attending Social Norms Marketing Research Project campuses varying by “wetness” and by drinking styles of matriculating students. Second, the model predicts that a combination of simulated interventions targeting heavy episodic drinkers at a moderately “dry” campus would extinguish heavy episodic drinkers, replacing them with light and moderate drinkers. Instituting the same combination of simulated interventions at a moderately “wet” campus would result in only a moderate reduction in heavy episodic drinkers (i.e., 50% to 35%). Conclusions: A simple, five-state compartmental model adequately predicted the actual drinking patterns of students from a variety of campuses surveyed in the Social Norms Marketing Research Project study. The model predicted the impact on drinking patterns of several simulated interventions to address heavy episodic drinking on various types of campuses. PMID:19737506

A site-specific screening comparison of modeled and monitored air dispersion and deposition for perfluorooctanoate.

PubMed

Barton, Catherine A; Zarzecki, Charles J; Russell, Mark H

2010-04-01

This work assessed the usefulness of a current air quality model (American Meteorological Society/Environmental Protection Agency Regulatory Model [AERMOD]) for predicting air concentrations and deposition of perfluorooctanoate (PFO) near a manufacturing facility. Air quality models play an important role in providing information for verifying permitting conditions and for exposure assessment purposes. It is important to ensure traditional modeling approaches are applicable to perfluorinated compounds, which are known to have unusual properties. Measured field data were compared with modeling predictions to show that AERMOD adequately located the maximum air concentration in the study area, provided representative or conservative air concentration estimates, and demonstrated bias and scatter not significantly different than that reported for other compounds. Surface soil/grass concentrations resulting from modeled deposition flux also showed acceptable bias and scatter compared with measured concentrations of PFO in soil/grass samples. Errors in predictions of air concentrations or deposition may be best explained by meteorological input uncertainty and conservatism in the PRIME algorithm used to account for building downwash. In general, AERMOD was found to be a useful screening tool for modeling the dispersion and deposition of PFO in air near a manufacturing facility.

A mathematical model for simulating spring discharge and estimating sinkhole porosity in a karst watershed

NASA Astrophysics Data System (ADS)

Li, Guangquan; Field, Malcolm S.

2014-03-01

Documenting and understanding water balances in a karst watershed in which groundwater and surface water resources are strongly interconnected are important aspects for managing regional water resources. Assessing water balances in karst watersheds can be difficult, however, because karst watersheds are so very strongly affected by groundwater flows through solution conduits that are often connected to one or more sinkholes. In this paper we develop a mathematical model to approximate sinkhole porosity from discharge at a downstream spring. The model represents a combination of a traditional linear reservoir model with turbulent hydrodynamics in the solution conduit connecting the downstream spring with the upstream sinkhole, which allows for the simulation of spring discharges and estimation of sinkhole porosity. Noting that spring discharge is an integral of all aspects of water storage and flow, it is mainly dependent on the behavior of the karst aquifer as a whole and can be adequately simulated using the analytical model described in this paper. The model is advantageous in that it obviates the need for a sophisticated numerical model that is much more costly to calibrate and operate. The model is demonstrated using the St. Marks River Watershed in northwestern Florida.

Kinetic modelling of ascorbic and dehydroascorbic acids concentrations in a model solution at different temperatures and oxygen contents.

PubMed

Gómez Ruiz, Braulio; Roux, Stéphanie; Courtois, Francis; Bonazzi, Catherine

2018-04-01

The degradation kinetics of vitamin C (ascorbic and dehydroascorbic acids, AA and DHA) were determined under controlled conditions of temperature (50-90 °C) and oxygen concentrations in the gas phase (10-30% mol/mol) using a specific reactor. The degradation of vitamin C in malate buffer (20 mM, pH 3.8), mimetic of an apple puree, was assessed by sampling at regular intervals and spectrophotometric quantification of AA and DHA levels at 243 nm. The results showed that AA degradation increased with temperature and oxygen concentration, while DHA exhibited the behaviour of an intermediate species, appearing then disappearing. A kinetic model was successfully developed to simulate the experimental data by two first order consecutive reactions. The first one represented AA degradation as a function of temperature and concentration in dissolved oxygen, and the second reflected DHA degradation as a function of temperature only, both adequately following Arrhenius' law. Copyright © 2018 Elsevier Ltd. All rights reserved.

On Supporting Physical Skill Discovery

NASA Astrophysics Data System (ADS)

Furukawa, Koichi; Suwa, Masaki; Kato, Takaaki

One of the main difficulties in motor skill acquisition is attributed to body control based on wrong mental models. This is true to various domains such as playing sports and playing musical instruments. In order to acquire adequate motor skill by modifying false belief, we need to help people find appropriate key points in achieving a body control and integrate them. In this paper, we investigate three approaches to realize such support. The first one is to encourage exploration of the relations among key points constituting a motor skill, using a technique of meta-cognitive verbalization. The second one is to represent a motor skill by appropriate mechanical models. The third one is to integrate rules for component tasks in achieving a compound task. These three approaches, we argue, help people build an integrated mental model consisting of multiple relations among various key points, one that seems to be indispensable for acquisition of motor skills. These ideas suggest the possibility to create new skill rules to perform difficult tasks automatically.

Large-Eddy Simulation of Waked Turbines in a Scaled Wind Farm Facility

NASA Astrophysics Data System (ADS)

Wang, J.; McLean, D.; Campagnolo, F.; Yu, T.; Bottasso, C. L.

2017-05-01

The aim of this paper is to present the numerical simulation of waked scaled wind turbines operating in a boundary layer wind tunnel. The simulation uses a LES-lifting-line numerical model. An immersed boundary method in conjunction with an adequate wall model is used to represent the effects of both the wind turbine nacelle and tower, which are shown to have a considerable effect on the wake behavior. Multi-airfoil data calibrated at different Reynolds numbers are used to account for the lift and drag characteristics at the low and varying Reynolds conditions encountered in the experiments. The present study focuses on low turbulence inflow conditions and inflow non-uniformity due to wind tunnel characteristics, while higher turbulence conditions are considered in a separate study. The numerical model is validated by using experimental data obtained during test campaigns conducted with the scaled wind farm facility. The simulation and experimental results are compared in terms of power capture, rotor thrust, downstream velocity profiles and turbulence intensity.

What experimental approaches (eg, in vivo, in vitro, tissue retrieval) are effective in investigating the biologic effects of particles?

PubMed Central

Bostrom, Mathias; O'Keefe, Regis

2009-01-01

Understanding the complex cellular and tissue mechanisms and interactions resulting in periprosthetic osteolysis requires a number of experimental approaches, each of which has its own set of advantages and limitations. In vitro models allow for the isolation of individual cell populations and have furthered our understanding of particle-cell interactions; however, they are limited because they do not mimic the complex tissue environment in which multiple cell interactions occur. In vivo animal models investigate the tissue interactions associated with periprosthetic osteolysis, but the choice of species and whether the implant system is subjected to mechanical load or to unloaded conditions are critical in assessing whether these models can be extrapolated to the clinical condition. Rigid analysis of retrieved tissue from clinical cases of osteolysis offers a different approach to studying the biologic process of osteolysis, but it is limited in that the tissue analyzed represents the end-stage of this process and, thus, may not reflect this process adequately. PMID:18612016

What experimental approaches (eg, in vivo, in vitro, tissue retrieval) are effective in investigating the biologic effects of particles?

PubMed

Bostrom, Mathias; O'Keefe, Regis

2008-01-01

Understanding the complex cellular and tissue mechanisms and interactions resulting in periprosthetic osteolysis requires a number of experimental approaches, each of which has its own set of advantages and limitations. In vitro models allow for the isolation of individual cell populations and have furthered our understanding of particle-cell interactions; however, they are limited because they do not mimic the complex tissue environment in which multiple cell interactions occur. In vivo animal models investigate the tissue interactions associated with periprosthetic osteolysis, but the choice of species and whether the implant system is subjected to mechanical load or to unloaded conditions are critical in assessing whether these models can be extrapolated to the clinical condition. Rigid analysis of retrieved tissue from clinical cases of osteolysis offers a different approach to studying the biologic process of osteolysis, but it is limited in that the tissue analyzed represents the end-stage of this process and, thus, may not reflect this process adequately.

A preliminary sensitivity analysis of the coupled diffusion and chemistry model. [effect of SST operations on ambient ozone in lower stratosphere

NASA Technical Reports Server (NTRS)

Hilst, G. R.; Contiliano, R. M.

1973-01-01

The sensitivity of the coupled chemistry/diffusion model's outputs to a wide range of variation of the model's independent variables has been investigated. It is shown that the efficiency with which the now catalytic cycle destroys ambient O3 is extremely sensitive to the amount of NO emitted and to the relative rates of turbulent diffusion and chemical reactions. For representative conditions in the stratosphere, a tenfold variation of either the turbulence intensity or the reaction rate constant or the source strength can vary the efficiency from 1% to 50%. If the duration of Phase 3 is a significant fraction of the total residence time of the plume, then these efficiency variations can alter O3 depletion rates by more than a factor of two. These results, therefore, point toward those variables which must be accurately defined or measured if one is to adequately predict the effect of SST operations on the ambient inventory of O3 in the lower stratosphere.

A sophisticated simulation for the fracture behavior of concrete material using XFEM

NASA Astrophysics Data System (ADS)

Zhai, Changhai; Wang, Xiaomin; Kong, Jingchang; Li, Shuang; Xie, Lili

2017-10-01

The development of a powerful numerical model to simulate the fracture behavior of concrete material has long been one of the dominant research areas in earthquake engineering. A reliable model should be able to adequately represent the discontinuous characteristics of cracks and simulate various failure behaviors under complicated loading conditions. In this paper, a numerical formulation, which incorporates a sophisticated rigid-plastic interface constitutive model coupling cohesion softening, contact, friction and shear dilatation into the XFEM, is proposed to describe various crack behaviors of concrete material. An effective numerical integration scheme for accurately assembling the contribution to the weak form on both sides of the discontinuity is introduced. The effectiveness of the proposed method has been assessed by simulating several well-known experimental tests. It is concluded that the numerical method can successfully capture the crack paths and accurately predict the fracture behavior of concrete structures. The influence of mode-II parameters on the mixed-mode fracture behavior is further investigated to better determine these parameters.

Measurements and Computations of Flow in an Urban Street System

NASA Astrophysics Data System (ADS)

Castro, Ian P.; Xie, Zheng-Tong; Fuka, V.; Robins, Alan G.; Carpentieri, M.; Hayden, P.; Hertwig, D.; Coceal, O.

2017-02-01

We present results from laboratory and computational experiments on the turbulent flow over an array of rectangular blocks modelling a typical, asymmetric urban canopy at various orientations to the approach flow. The work forms part of a larger study on dispersion within such arrays (project DIPLOS) and concentrates on the nature of the mean flow and turbulence fields within the canopy region, recognising that unless the flow field is adequately represented in computational models there is no reason to expect realistic simulations of the nature of the dispersion of pollutants emitted within the canopy. Comparisons between the experimental data and those obtained from both large-eddy simulation (LES) and direct numerical simulation (DNS) are shown and it is concluded that careful use of LES can produce generally excellent agreement with laboratory and DNS results, lending further confidence in the use of LES for such situations. Various crucial issues are discussed and advice offered to both experimentalists and those seeking to compute canopy flows with turbulence resolving models.

High-quality unsaturated zone hydraulic property data for hydrologic applications

USGS Publications Warehouse

Perkins, Kimberlie; Nimmo, John R.

2009-01-01

In hydrologic studies, especially those using dynamic unsaturated zone moisture modeling, calculations based on property transfer models informed by hydraulic property databases are often used in lieu of measured data from the site of interest. Reliance on database-informed predicted values has become increasingly common with the use of neural networks. High-quality data are needed for databases used in this way and for theoretical and property transfer model development and testing. Hydraulic properties predicted on the basis of existing databases may be adequate in some applications but not others. An obvious problem occurs when the available database has few or no data for samples that are closely related to the medium of interest. The data set presented in this paper includes saturated and unsaturated hydraulic conductivity, water retention, particle-size distributions, and bulk properties. All samples are minimally disturbed, all measurements were performed using the same state of the art techniques and the environments represented are diverse.

Control Augmented Structural Synthesis

NASA Technical Reports Server (NTRS)

Lust, Robert V.; Schmit, Lucien A.

1988-01-01

A methodology for control augmented structural synthesis is proposed for a class of structures which can be modeled as an assemblage of frame and/or truss elements. It is assumed that both the plant (structure) and the active control system dynamics can be adequately represented with a linear model. The structural sizing variables, active control system feedback gains and nonstructural lumped masses are treated simultaneously as independent design variables. Design constraints are imposed on static and dynamic displacements, static stresses, actuator forces and natural frequencies to ensure acceptable system behavior. Multiple static and dynamic loading conditions are considered. Side constraints imposed on the design variables protect against the generation of unrealizable designs. While the proposed approach is fundamentally more general, here the methodology is developed and demonstrated for the case where: (1) the dynamic loading is harmonic and thus the steady state response is of primary interest; (2) direct output feedback is used for the control system model; and (3) the actuators and sensors are collocated.

The traveling salesman problem: a hierarchical model.

PubMed

Graham, S M; Joshi, A; Pizlo, Z

2000-10-01

Our review of prior literature on spatial information processing in perception, attention, and memory indicates that these cognitive functions involve similar mechanisms based on a hierarchical architecture. The present study extends the application of hierarchical models to the area of problem solving. First, we report results of an experiment in which human subjects were tested on a Euclidean traveling salesman problem (TSP) with 6 to 30 cities. The subject's solutions were either optimal or near-optimal in length and were produced in a time that was, on average, a linear function of the number of cities. Next, the performance of the subjects is compared with that of five representative artificial intelligence and operations research algorithms, that produce approximate solutions for Euclidean problems. None of these algorithms was found to be an adequate psychological model. Finally, we present a new algorithm for solving the TSP, which is based on a hierarchical pyramid architecture. The performance of this new algorithm is quite similar to the performance of the subjects.

Spatial analysis and statistical modelling of snow cover dynamics in the Central Himalayas, Nepal

NASA Astrophysics Data System (ADS)

Weidinger, Johannes; Gerlitz, Lars; Böhner, Jürgen

2017-04-01

General circulation models are able to predict large scale climate variations in global dimensions, however small scale dynamic characteristics, such as snow cover and its temporal variations in high mountain regions, are not represented sufficiently. Detailed knowledge about shifts in seasonal ablation times and spatial distribution of snow cover are crucial for various research interests. Since high mountain areas, for instance the Central Himalayas in Nepal, are generally remote, it is difficult to obtain data in high spatio-temporal resolutions. Regional climate models and downscaling techniques are implemented to compensate coarse resolution. Furthermore earth observation systems, such as MODIS, also permit bridging this gap to a certain extent. They offer snow (cover) data in daily temporal and medium spatial resolution of around 500 m, which can be applied as evaluation and training data for dynamical hydrological and statistical analyses. Within this approach two snow distribution models (binary snow cover and fractional snow cover) as well as one snow recession model were implemented for a research domain in the Rolwaling Himal in Nepal, employing the random forest technique, which represents a state of the art machine learning algorithm. Both bottom-up strategies provide inductive reasoning to derive rules for snow related processes out of climate (temperature, precipitation and irradiance) and climate-related topographic data sets (elevation, aspect and convergence index) obtained by meteorological network stations, remote sensing products (snow cover - MOD10-A1 and land surface temperatures - MOD11-A1) along with GIS. Snow distribution is predicted reliably on a daily basis in the research area, whereas further effort is necessary for predicting daily snow cover recession processes adequately. Swift changes induced by clear sky conditions with high insolation rates are well represented, whereas steady snow loss still needs continuing effort. All approaches underline the technical difficulties of snow cover modelling during the monsoon season, in accordance with previous studies. The developed methods in combination with continuous in situ measurements provide a basis for further downscaling approaches.

A CAD Approach to Developing Mass Distribution and Composition Models for Spaceflight Radiation Risk Analyses

NASA Astrophysics Data System (ADS)

Zapp, E.; Shelfer, T.; Semones, E.; Johnson, A.; Weyland, M.; Golightly, M.; Smith, G.; Dardano, C.

For roughly the past three decades, combinatorial geometries have been the predominant mode for the development of mass distribution models associated with the estimation of radiological risk for manned space flight. Examples of these are the MEVDP (Modified Elemental Volume Dose Program) vehicle representation of Liley and Hamilton, and the quadratic functional representation of the CAM/CAF (Computerized Anatomical Male/Female) human body models as modified by Billings and Yucker. These geometries, have the advantageous characteristics of being simple for a familiarized user to maintain, and because of the relative lack of any operating system or run-time library dependence, they are also easy to transfer from one computing platform to another. Unfortunately they are also limited in the amount of modeling detail possible, owing to the abstract geometric representation. In addition, combinatorial representations are also known to be error-prone in practice, since there is no convenient method for error identification (i.e. overlap, etc.), and extensive calculation and/or manual comparison may is often necessary to demonstrate that the geometry is adequately represented. We present an alternate approach linking materials -specific, CAD-based mass models directly to geometric analysis tools requiring no approximation with respect to materials , nor any meshing (i.e. tessellation) of the representative geometry. A new approach to ray tracing is presented which makes use of the fundamentals of the CAD representation to perform geometric analysis directly on the NURBS (Non-Uniform Rational BSpline) surfaces themselves. In this way we achieve a framework for- the rapid, precise development and analysis of materials-specific mass distribution models.

PHYSICS REQUIRES A SIMPLE LOW MACH NUMBER FLOW TO BE COMPRESSIBLE

EPA Science Inventory

Radial, laminar, plane, low velocity flow represents the simplest, non-linear fluid dynamics problem. Ostensibly this apparently trivial flow could be solved using the incompressible Navier-Stokes equations, universally believed to be adequate for such problems. Most researchers ...

34 CFR 668.146 - Criteria for approving tests.

Code of Federal Regulations, 2010 CFR

2010-07-01

... approved under this subpart, a test shall— (1) Assess secondary school level basic verbal and quantitative... verbal and quantitative skills with sufficient numbers of questions to— (i) Adequately represent each... the American Educational Research Association, the American Psychological Association, and the...

Towards a physically-based multi-scale ecohydrological simulator for semi-arid regions

NASA Astrophysics Data System (ADS)

Caviedes-Voullième, Daniel; Josefik, Zoltan; Hinz, Christoph

2017-04-01

The use of numerical models as tools for describing and understanding complex ecohydrological systems has enabled to test hypothesis and propose fundamental, process-based explanations of the system system behaviour as a whole as well as its internal dynamics. Reaction-diffusion equations have been used to describe and generate organized pattern such as bands, spots, and labyrinths using simple feedback mechanisms and boundary conditions. Alternatively, pattern-matching cellular automaton models have been used to generate vegetation self-organization in arid and semi-arid regions also using simple description of surface hydrological processes. A key question is: How much physical realism is needed in order to adequately capture the pattern formation processes in semi-arid regions while reliably representing the water balance dynamics at the relevant time scales? In fact, redistribution of water by surface runoff at the hillslope scale occurs at temporal resolution of minutes while the vegetation development requires much lower temporal resolution and longer times spans. This generates a fundamental spatio-temporal multi-scale problem to be solved, for which high resolution rainfall and surface topography are required. Accordingly, the objective of this contribution is to provide proof-of-concept that governing processes can be described numerically at those multiple scales. The requirements for a simulating ecohydrological processes and pattern formation with increased physical realism are, amongst others: i. high resolution rainfall that adequately captures the triggers of growth as vegetation dynamics of arid regions respond as pulsed systems. ii. complex, natural topography in order to accurately model drainage patterns, as surface water redistribution is highly sensitive to topographic features. iii. microtopography and hydraulic roughness, as small scale variations do impact on large scale hillslope behaviour iv. moisture dependent infiltration as temporal dynamics of infiltration affects water storage under vegetation and in bare soil Despite the volume of research in this field, fundamental limitations still exist in the models regarding the aforementioned issues. Topography and hydrodynamics have been strongly simplified. Infiltration has been modelled as dependent on depth but independent of soil moisture. Temporal rainfall variability has only been addressed for seasonal rain. Spatial heterogenity of the topography as well as roughness and infiltration properties, has not been fully and explicitly represented. We hypothesize that physical processes must be robustly modelled and the drivers of complexity must be present with as much resolution as possible in order to provide the necessary realism to improve transient simulations, perhaps leading the way to virtual laboratories and, arguably, predictive tools. This work provides a first approach into a model with explicit hydrological processes represented by physically-based hydrodynamic models, coupled with well-accepted vegetation models. The model aims to enable new possibilities relating to spatiotemporal variability, arbitrary topography and representation of spatial heterogeneity, including sub-daily (in fact, arbitrary) temporal variability of rain as the main forcing of the model, explicit representation of infiltration processes, and various feedback mechanisms between the hydrodynamics and the vegetation. Preliminary testing strongly suggests that the model is viable, has the potential of producing new information of internal dynamics of the system, and allows to successfully aggregate many of the sources of complexity. Initial benchmarking of the model also reveals strengths to be exploited, thus providing an interesting research outlook, as well as weaknesses to be addressed in the immediate future.

Computer simulation of surface and film processes

NASA Technical Reports Server (NTRS)

Tiller, W. A.; Halicioglu, M. T.

1983-01-01

Adequate computer methods, based on interactions between discrete particles, provide information leading to an atomic level understanding of various physical processes. The success of these simulation methods, however, is related to the accuracy of the potential energy function representing the interactions among the particles. The development of a potential energy function for crystalline SiO2 forms that can be employed in lengthy computer modelling procedures was investigated. In many of the simulation methods which deal with discrete particles, semiempirical two body potentials were employed to analyze energy and structure related properties of the system. Many body interactions are required for a proper representation of the total energy for many systems. Many body interactions for simulations based on discrete particles are discussed.

A CityGML Extension for Handling Very Large Tins

NASA Astrophysics Data System (ADS)

Kumar, K.; Ledoux, H.; Stoter, J.

2016-10-01

In addition to buildings, the terrain forms an important part of a 3D city model. Although in GIS terrains are usually represented with 2D grids, TINs are also increasingly being used in practice. One example is 3DTOP10NL, the 3D city model covering the whole of the Netherlands, which stores the relief with a constrained TIN containing more than 1 billion triangles. Due to the massive size of such datasets, the main problem that arises is: how to efficiently store and maintain them? While CityGML supports the storage of TINs, we argue in this paper that the current solution is not adequate. For instance, the 1 billion+ triangles of 3DTOP10NL require 686 GB of storage space with CityGML. Furthermore, the current solution does not store the topological relationships of the triangles, and also there are no clear mechanisms to handle several LODs. We propose in this paper a CityGML extension for the compact representation of terrains. We describe our abstract and implementation specifications (modelled in UML), and our prototype implementation to convert TINs to our CityGML structure. It increases the topological relationships that are explicitly represented, and allows us to compress up to a factor of ∼ 25 in our experiments with massive real-world terrains (more than 1 billion triangles).

Assessing state-wide biodiversity in the Florida Gap analysis project

USGS Publications Warehouse

Pearlstine, L.G.; Smith, S.E.; Brandt, L.A.; Allen, Craig R.; Kitchens, W.M.; Stenberg, J.

2002-01-01

The Florida Gap (FI-Gap) project provides an assessment of the degree to which native animal species and natural communities are or are not represented in existing conservation lands. Those species and communities not adequately represented in areas being managed for native species constitute 'gaps' in the existing network of conservation lands. The United States Geological Survey Gap Analysis Program is a national effort and so, eventually, all 50 states will have completed it. The objective of FI-Gap was to provide broad geographic information on the status of terrestrial vertebrates, butterflies, skippers and ants and their respective habitats to address the loss of biological diversity. To model the distributions and potential habitat of all terrestrial species of mammals, breeding birds, reptiles, amphibians, butterflies, skippers and ants in Florida, natural land cover was mapped to the level of dominant or co-dominant plant species. Land cover was classified from Landsat Thematic Mapper (TM) satellite imagery and auxiliary data such as the national wetlands inventory (NWI), soils maps, aerial imagery, existing land use/land cover maps, and on-the-ground surveys, Wildlife distribution models were produced by identifying suitable habitat for each species within that species' range, Mammalian models also assessed a minimum critical area required for sustainability of the species' population. Wildlife species richness was summarized against land stewardship ranked by an area's mandates for conservation protection. ?? 2002 Elsevier Science Ltd. All rights reserved.

IGLOO: an Intermediate Complexity Framework to Simulate Greenland Ice-Ocean Interactions

NASA Astrophysics Data System (ADS)

Perrette, M.; Calov, R.; Beckmann, J.; Alexander, D.; Beyer, S.; Ganopolski, A.

2017-12-01

The Greenland ice-sheet is a major contributor to current and future sea level rise associated to climate warming. It is widely believed that over a century time scale, surface melting is the main driver of Greenland ice volume change, in contrast to melting by the ocean. It is due to relatively warmer air and less ice area exposed to melting by ocean water compared to Antarctica, its southern, larger twin. Yet most modeling studies do not have adequate grid resolution to represent fine-scale outlet glaciers and fjords at the margin of the ice sheet, where ice-ocean interaction occurs, and must use rather crude parameterizations to represent this process. Additionally, the ice-sheet area grounded below sea level has been reassessed upwards in the most recent estimates of bedrock elevation under the Greenland ice sheet, revealing a larger potential for marine-mediated melting than previously thought. In this work, we develop an original approach to estimate potential Greenland ice sheet contribution to sea level rise from ocean melting, in an intermediate complexity framework, IGLOO. We use a medium-resolution (5km) ice-sheet model coupled interactively to a number of 1-D flowline models for the individual outlet glaciers. We propose a semi-objective methodology to derive 1-D glacier geometries from 2-D Greenland datasets, as well as preliminary results of coupled ice-sheet-glaciers simulations with IGLOO.

Development and evaluation of the Internalized Racism in Asian Americans Scale (IRAAS).

PubMed

Choi, Andrew Young; Israel, Tania; Maeda, Hotaka

2017-01-01

This article presents the development and psychometric evaluation of the Internalized Racism in Asian Americans Scale (IRAAS), which was designed to measure the degree to which Asian Americans internalized hostile attitudes and negative messages targeted toward their racial identity. Items were developed on basis of prior literature, vetted through expert feedback and cognitive interviews, and administered to 655 Asian American participants through Amazon Mechanical Turk. Exploratory factor analysis with a random subsample (n = 324) yielded a psychometrically robust preliminary measurement model consisting of 3 factors: Self-Negativity, Weakness Stereotypes, and Appearance Bias. Confirmatory factor analysis with a separate subsample (n = 331) indicated that the proposed correlated factors model was strongly consistent with the observed data. Factor determinacies were high and demonstrated that the specified items adequately measured their intended factors. Bifactor modeling further indicated that this multidimensionality could be univocally represented for the purpose of measurement, including the use of a mean total score representing a single continuum of internalized racism on which individuals vary. The IRAAS statistically predicted depressive symptoms, and demonstrated statistically significant correlations in theoretically expected directions with four dimensions of collective self-esteem. These results provide initial validity evidence supporting the use of the IRAAS to measure aspects of internalized racism in this population. Limitations and research implications are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The resilience and functional role of moss in boreal and arctic ecosystems

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

Turetsky, Merritt; Bond-Lamberty, Benjamin; Euskirchen, Eugenie S.

2012-08-24

Mosses in boreal and arctic ecosystems are ubiquitous components of plant communities, represent an important component of plant diversity, and strongly influence the cycling of water, nutrients, energy and carbon. Here we use a literature review and synthesis as well as model simulations to explore the role of moss in ecological stability and resilience. Our literature review of moss community responses to disturbance showed all possible responses (increases, decreases, no change) within most disturbance categories in boreal and arctic regions. Our modeling simulations suggest that loss of moss within northern plant communities will reduce soil carbon accumulation primarily by influencingmore » decomposition rates and soil nitrogen availability. While two models (HPM and STM-TEM) showed a significant effect of moss removal, results from the Biome-BGC and DVM-TEM models suggest that northern, moss-rich ecosystems would need to experience extreme perturbation before mosses were eliminated. We highlight a number of issues that have not been adequately explored in moss communities, such as functional redundancy and singularity, relationships between response and effect traits, phenotypical plasticity in traits, and whether the effects of moss on ecosystem processes scale with local abundance. We also suggest that as more models explore issues related to ecological resilience, issues related to both parameter and conceptual uncertainty should be addressed: are the models more limited by uncertainty in the parameterization of the processes included or by what is not represented in the model at all? It seems clear from our review that mosses need to be incorporated into models as one or more plant functional types, but more empirical work is needed to determine how to best aggregate species.« less

Evaluating simulated functional trait patterns and quantifying modelled trait diversity effects on simulated ecosystem fluxes

NASA Astrophysics Data System (ADS)

Pavlick, R.; Schimel, D.

2014-12-01

Dynamic Global Vegetation Models (DGVMs) typically employ only a small set of Plant Functional Types (PFTs) to represent the vast diversity of observed vegetation forms and functioning. There is growing evidence, however, that this abstraction may not adequately represent the observed variation in plant functional traits, which is thought to play an important role for many ecosystem functions and for ecosystem resilience to environmental change. The geographic distribution of PFTs in these models is also often based on empirical relationships between present-day climate and vegetation patterns. Projections of future climate change, however, point toward the possibility of novel regional climates, which could lead to no-analog vegetation compositions incompatible with the PFT paradigm. Here, we present results from the Jena Diversity-DGVM (JeDi-DGVM), a novel traits-based vegetation model, which simulates a large number of hypothetical plant growth strategies constrained by functional tradeoffs, thereby allowing for a more flexible temporal and spatial representation of the terrestrial biosphere. First, we compare simulated present-day geographical patterns of functional traits with empirical trait observations (in-situ and from airborne imaging spectroscopy). The observed trait patterns are then used to improve the tradeoff parameterizations of JeDi-DGVM. Finally, focusing primarily on the simulated leaf traits, we run the model with various amounts of trait diversity. We quantify the effects of these modeled biodiversity manipulations on simulated ecosystem fluxes and stocks for both present-day conditions and transient climate change scenarios. The simulation results reveal that the coarse treatment of plant functional traits by current PFT-based vegetation models may contribute substantial uncertainty regarding carbon-climate feedbacks. Further development of trait-based models and further investment in global in-situ and spectroscopic plant trait observations are needed.

Numerical simulation of distributed snow processes in complex terrain utilizing triangulated irregular networks (TINs)

NASA Astrophysics Data System (ADS)

Rinehart, A. J.; Vivoni, E. R.

2005-12-01

Snow processes play a significant role in the hydrologic cycle of mountainous and high-latitude catchments in the western United States. Snowmelt runoff contributes to a large percentage of stream runoff while snow covered regions remain highly localized to small portions of the catchment area. The appropriate representation of snow dynamics at a given range of spatial and temporal scales is critical for adequately predicting runoff responses in snowmelt-dominated watersheds. In particular, the accurate depiction of snow cover patterns is important as a range of topographic, land-use and geographic parameters create zones of preferential snow accumulation or ablation that significantly affect the timing of a region's snow melt and the persistence of a snow pack. In this study, we present the development and testing of a distributed snow model designed for simulations over complex terrain. The snow model is developed within the context of the TIN-based Real-time Integrated Basin Simulator (tRIBS), a fully-distributed watershed model capable of continuous simulations of coupled hydrological processes, including unsaturated-saturated zone dynamics, land-atmosphere interactions and runoff generation via multiple mechanisms. The use of triangulated irregular networks as a domain discretization allows tRIBS to accurately represent topography with a reduced number of computational nodes, as compared to traditional grid-based models. This representation is developed using a Delauney optimization criterion that causes areas of topographic homogeneity to be represented at larger spatial scales than the original grid, while more heterogeneous areas are represented at higher resolutions. We utilize the TIN-based terrain representation to simulate microscale (10-m to 100-m) snow pack dynamics over a catchment. The model includes processes such as the snow pack energy balance, wind and bulk redistribution, and snow interception by vegetation. For this study, we present tests from a distributed one-layer energy balance model as applied to a northern New Mexico hillslope in a ponderosa pine forest using both synthetic and real meteorological forcing. We also provide tests of the model's capability to represent spatial patterns within a small watershed in the Jemez Mountain region. Finally, we discuss the interaction of the tested snow process module with existing components in the watershed model and additional applications and capabilities under development.

The Evolution of Tyrosine-Recombinase Elements in Nematoda

PubMed Central

Szitenberg, Amir; Koutsovoulos, Georgios; Blaxter, Mark L.; Lunt, David H.

2014-01-01

Transposable elements can be categorised into DNA and RNA elements based on their mechanism of transposition. Tyrosine recombinase elements (YREs) are relatively rare and poorly understood, despite sharing characteristics with both DNA and RNA elements. Previously, the Nematoda have been reported to have a substantially different diversity of YREs compared to other animal phyla: the Dirs1-like YRE retrotransposon was encountered in most animal phyla but not in Nematoda, and a unique Pat1-like YRE retrotransposon has only been recorded from Nematoda. We explored the diversity of YREs in Nematoda by sampling broadly across the phylum and including 34 genomes representing the three classes within Nematoda. We developed a method to isolate and classify YREs based on both feature organization and phylogenetic relationships in an open and reproducible workflow. We also ensured that our phylogenetic approach to YRE classification identified truncated and degenerate elements, informatively increasing the number of elements sampled. We identified Dirs1-like elements (thought to be absent from Nematoda) in the nematode classes Enoplia and Dorylaimia indicating that nematode model species do not adequately represent the diversity of transposable elements in the phylum. Nematode Pat1-like elements were found to be a derived form of another Pat1-like element that is present more widely in animals. Several sequence features used widely for the classification of YREs were found to be homoplasious, highlighting the need for a phylogenetically-based classification scheme. Nematode model species do not represent the diversity of transposable elements in the phylum. PMID:25197791

The evolution of tyrosine-recombinase elements in Nematoda.

PubMed

Szitenberg, Amir; Koutsovoulos, Georgios; Blaxter, Mark L; Lunt, David H

2014-01-01

Transposable elements can be categorised into DNA and RNA elements based on their mechanism of transposition. Tyrosine recombinase elements (YREs) are relatively rare and poorly understood, despite sharing characteristics with both DNA and RNA elements. Previously, the Nematoda have been reported to have a substantially different diversity of YREs compared to other animal phyla: the Dirs1-like YRE retrotransposon was encountered in most animal phyla but not in Nematoda, and a unique Pat1-like YRE retrotransposon has only been recorded from Nematoda. We explored the diversity of YREs in Nematoda by sampling broadly across the phylum and including 34 genomes representing the three classes within Nematoda. We developed a method to isolate and classify YREs based on both feature organization and phylogenetic relationships in an open and reproducible workflow. We also ensured that our phylogenetic approach to YRE classification identified truncated and degenerate elements, informatively increasing the number of elements sampled. We identified Dirs1-like elements (thought to be absent from Nematoda) in the nematode classes Enoplia and Dorylaimia indicating that nematode model species do not adequately represent the diversity of transposable elements in the phylum. Nematode Pat1-like elements were found to be a derived form of another Pat1-like element that is present more widely in animals. Several sequence features used widely for the classification of YREs were found to be homoplasious, highlighting the need for a phylogenetically-based classification scheme. Nematode model species do not represent the diversity of transposable elements in the phylum.

Laser safety eyewear.

PubMed

1993-04-01

In spite of repeated warnings about laser safety practices, as well as the availability of laser safety eyewear (LSE), eye injuries continue to occur during use of surgical lasers, as discussed in the Clinical Perspective, "Laser Energy and Its Dangers to Eyes," preceding this Evaluation. We evaluated 48 models of LSE, including goggles, spectacles, and wraps, from 11 manufacturers. The evaluated models are designed with absorptive lenses that provide protection from CO2 (carbon dioxide), Nd:YAG (neodymium:yttrium-aluminum-garnet), and 532 (frequency-doubled Nd:YAG) surgical laser wavelengths; several models provide multiwavelength protection. (Refer to ECRI's Product Comparison System report on LSE for specifications of other models.) Although most of the evaluated models can adequately protect users from laser energy--provided that the eyewear is used--many models of LSE, especially goggles, are designed with little regard for the needs of actual use (e.g., adequate labeling, no alteration of color perception, sufficient field of vision [FOV], comfort). Because these factors can discourage people from using LSE, we encourage manufacturers to develop new and improved models that will be worn. We based our ratings primarily on the laser protection provided by the optical density (OD) of the lenses; we acknowledge the contribution of Montana Laser Optics Inc., of Bozeman, Montana, in performing our OD testing. We also considered actual-use factors, such as those mentioned above, to be significant. Among the models rated Acceptable is one whose labeled OD is lower than the level we determined to be adequate for use during most laser surgery; however, this model offers protection under specific conditions of use (e.g., for use by spectators some distance from the surgical site, for use during endoscopic procedures) that should be determined by the laser safety officer (LSO). LSE that would put the wearer at risk are rated Unacceptable (e.g., some models are not properly or clearly labeled, have measured ODs that are not adequate for protection, or significantly restrict the wearer's FOV); also, LSE with side shields that do not offer adequate protection from diffuse laser energy are rated Unacceptable. Those models that offer adequate protection for surgical applications, but whose measured OD is less than their labeled OD, are rated Acceptable--Not Recommended; if the discrepancy is great, they are rated Unacceptable. Those models whose labels were removed during cleaning are rated Conditionally Acceptable.(ABSTRACT TRUNCATED AT 400 WORDS)

Probabilistic biosphere modeling for the long-term safety assessment of geological disposal facilities for radioactive waste using first- and second-order Monte Carlo simulation.

PubMed

Ciecior, Willy; Röhlig, Klaus-Jürgen; Kirchner, Gerald

2018-10-01

In the present paper, deterministic as well as first- and second-order probabilistic biosphere modeling approaches are compared. Furthermore, the sensitivity of the influence of the probability distribution function shape (empirical distribution functions and fitted lognormal probability functions) representing the aleatory uncertainty (also called variability) of a radioecological model parameter as well as the role of interacting parameters are studied. Differences in the shape of the output distributions for the biosphere dose conversion factor from first-order Monte Carlo uncertainty analysis using empirical and fitted lognormal distribution functions for input parameters suggest that a lognormal approximation is possibly not always an adequate representation of the aleatory uncertainty of a radioecological parameter. Concerning the comparison of the impact of aleatory and epistemic parameter uncertainty on the biosphere dose conversion factor, the latter here is described using uncertain moments (mean, variance) while the distribution itself represents the aleatory uncertainty of the parameter. From the results obtained, the solution space of second-order Monte Carlo simulation is much larger than that from first-order Monte Carlo simulation. Therefore, the influence of epistemic uncertainty of a radioecological parameter on the output result is much larger than that one caused by its aleatory uncertainty. Parameter interactions are only of significant influence in the upper percentiles of the distribution of results as well as only in the region of the upper percentiles of the model parameters. Copyright © 2018 Elsevier Ltd. All rights reserved.

Base flow calibration in a global hydrological model

NASA Astrophysics Data System (ADS)

van Beek, L. P.; Bierkens, M. F.

2006-12-01

Base flow constitutes an important water resource in many parts of the world. Its provenance and yield over time are governed by the storage capacity of local aquifers and the internal drainage paths, which are difficult to capture at the global scale. To represent the spatial and temporal variability in base flow adequately in a distributed global model at 0.5 degree resolution, we resorted to the conceptual model of aquifer storage of Kraaijenhoff- van de Leur (1958) that yields the reservoir coefficient for a linear groundwater store. This model was parameterised using global information on drainage density, climatology and lithology. Initial estimates of aquifer thickness, permeability and specific porosity from literature were linked to the latter two categories and calibrated to low flow data by means of simulated annealing so as to conserve the ordinal information contained by them. The observations used stem from the RivDis dataset of monthly discharge. From this dataset 324 stations were selected with at least 10 years of observations in the period 1958-1991 and an areal coverage of at least 10 cells of 0.5 degree. The dataset was split between basins into a calibration and validation set whilst preserving a representative distribution of lithology types and climate zones. Optimisation involved minimising the absolute differences between the simulated base flow and the lowest 10% of the observed monthly discharge. Subsequently, the reliability of the calibrated parameters was tested by reversing the calibration and validation sets.

Dairy goat demography and Q fever infection dynamics

PubMed Central

2013-01-01

Between 2007 and 2009, the largest human Q fever epidemic ever described occurred in the Netherlands. The source was traced back to dairy goat farms, where abortion storms had been observed since 2005. Since one putative cause of these abortion storms is the intensive husbandry systems in which the goats are kept, the objective of this study was to assess whether these could be explained by herd size, reproductive pattern and other demographic aspects of Dutch dairy goat herds alone. We adapted an existing, fully parameterized simulation model for Q fever transmission in French dairy cattle herds to represent the demographics typical for Dutch dairy goat herds. The original model represents the infection dynamics in a herd of 50 dairy cows after introduction of a single infected animal; the adapted model has 770 dairy goats. For a full comparison, herds of 770 cows and 50 goats were also modeled. The effects of herd size and goat versus cattle demographics on the probability of and time to extinction of the infection, environmental bacterial load and abortion rate were studied by simulation. The abortion storms could not be fully explained by demographics alone. Adequate data were lacking at the moment to attribute the difference to characteristics of the pathogen, host, within-herd environment, or a combination thereof. The probability of extinction was higher in goat herds than in cattle herds of the same size. The environmental contamination was highest within cattle herds, which may be taken into account when enlarging cattle farming systems. PMID:23621908

Dairy goat demography and Q fever infection dynamics.

PubMed

Hogerwerf, Lenny; Courcoul, Aurélie; Klinkenberg, Don; Beaudeau, François; Vergu, Elisabeta; Nielen, Mirjam

2013-04-26

Between 2007 and 2009, the largest human Q fever epidemic ever described occurred in the Netherlands. The source was traced back to dairy goat farms, where abortion storms had been observed since 2005. Since one putative cause of these abortion storms is the intensive husbandry systems in which the goats are kept, the objective of this study was to assess whether these could be explained by herd size, reproductive pattern and other demographic aspects of Dutch dairy goat herds alone. We adapted an existing, fully parameterized simulation model for Q fever transmission in French dairy cattle herds to represent the demographics typical for Dutch dairy goat herds. The original model represents the infection dynamics in a herd of 50 dairy cows after introduction of a single infected animal; the adapted model has 770 dairy goats. For a full comparison, herds of 770 cows and 50 goats were also modeled. The effects of herd size and goat versus cattle demographics on the probability of and time to extinction of the infection, environmental bacterial load and abortion rate were studied by simulation. The abortion storms could not be fully explained by demographics alone. Adequate data were lacking at the moment to attribute the difference to characteristics of the pathogen, host, within-herd environment, or a combination thereof. The probability of extinction was higher in goat herds than in cattle herds of the same size. The environmental contamination was highest within cattle herds, which may be taken into account when enlarging cattle farming systems.

Peer exchange : journey from adequate to vital : the pathway to excellence.

DOT National Transportation Integrated Search

2013-06-01

This report documents the NMDOT Research Peer Exchange held April 10-11, 2013 in : Albuquerque, New Mexico in accordance with the requirements of 23 CFR 420. It : involved NMDOT staff and representatives from the state DOTs of Arizona, Ohio, : Texas,...

ELECTROFISHING EFFORT REQUIREMENTS FOR ASSESSING SPECIES RICHNESS AND BIOTIC INTEGRITY IN WESTERN OREGON STREAMS

EPA Science Inventory

We empirically examined the sampling effort required to adequately represent species richness and proportionate abundance when backpack electrofishing western Oregon streams. When sampling, we separately recorded data for each habitat unit. In data analyses, we repositioned each...

40 CFR 90.121 - Certification procedure-recordkeeping.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the engine, steps taken to insure that it is representative of production engines, description of... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NONROAD SPARK-IGNITION ENGINES AT OR BELOW 19 KILOWATTS... engine manufacturer must maintain the following adequately organized records: (1) Copies of all...

Wolf Creek Research Basin Cold REgion Process Studies - 1992-2003

NASA Astrophysics Data System (ADS)

Janowicz, R.; Hedstrom, N.; Pomeroy, J.; Granger, R.; Carey, S.

2004-12-01

The development of hydrological models in northern regions are complicated by cold region processes. Sparse vegetation influences snowpack accumulation, redistribution and melt, frozen ground effects infiltration and runoff and cold soils in the summer effect evapotranspiration rates. Situated in the upper Yukon River watershed, the 195 km2 Wolf Creek Research Basin was instrumented in 1992 to calibrate hydrologic flow models, and has since evolved into a comprehensive study of cold region processes and linkages, contributing significantly to hydrological and climate change modelling. Studies include those of precipitation distribution, snowpack accumulation and redistribution, energy balance, snowmelt infiltration, and water balance. Studies of the spatial variability of hydrometeorological data demonstrate the importance of physical parameters on their distribution and control on runoff processes. Many studies have also identified the complex interaction of several of the physical parameters, including topography, vegetation and frozen ground (seasonal or permafrost) as important. They also show that there is a fundamental, underlying spatial structure to the watershed that must be adequately represented in parameterization schemes for scaling and watershed modelling. The specific results of numerous studies are presented.

Effects of phase vector and history extension on prediction power of adaptive-network based fuzzy inference system (ANFIS) model for a real scale anaerobic wastewater treatment plant operating under unsteady state.

PubMed

Perendeci, Altinay; Arslan, Sever; Tanyolaç, Abdurrahman; Celebi, Serdar S

2009-10-01

A conceptual neural fuzzy model based on adaptive-network based fuzzy inference system, ANFIS, was proposed using available input on-line and off-line operational variables for a sugar factory anaerobic wastewater treatment plant operating under unsteady state to estimate the effluent chemical oxygen demand, COD. The predictive power of the developed model was improved as a new approach by adding the phase vector and the recent values of COD up to 5-10 days, longer than overall retention time of wastewater in the system. History of last 10 days for COD effluent with two-valued phase vector in the input variable matrix including all parameters had more predictive power. History of 7 days with two-valued phase vector in the matrix comprised of only on-line variables yielded fairly well estimations. The developed ANFIS model with phase vector and history extension has been able to adequately represent the behavior of the treatment system.

The Development of Skull Prosthesis Through Active Contour Model.

PubMed

Chen, Yi-Wen; Shih, Cheng-Ting; Cheng, Chen-Yang; Lin, Yu-Cheng

2017-09-09

Skull defects result in brain infection and inadequate brain protection and pose a general danger to patient health. To avoid these situations and prevent re-injury, a prosthesis must be constructed and grafted onto the deficient region. With the development of rapid customization through additive manufacturing and 3D printing technology, skull prostheses can be fabricated accurately and efficiently prior to cranioplasty. However, an unfitted skull prosthesis made with a metal implant can cause repeated infection, potentially necessitating secondary surgery. This paper presents a method of creating suitably geometric graphics of skull defects to be applied in skull repair through active contour models. These models can be adjusted in each computed tomography slice according to the graphic features, and the curves representing the skull defect can be modeled. The generated graphics can adequately mimic the natural curvature of the complete skull. This method will enable clinical surgeons to rapidly implant customized prostheses, which is of particular importance in emergency surgery. The findings of this research can help surgeons provide patients with skull defects with treatment of the highest quality.

On statistical analysis of factors affecting anthocyanin extraction from Ixora siamensis

NASA Astrophysics Data System (ADS)

Mat Nor, N. A.; Arof, A. K.

2016-10-01

This study focused on designing an experimental model in order to evaluate the influence of operative extraction parameters employed for anthocyanin extraction from Ixora siamensis on CIE color measurements (a*, b* and color saturation). Extractions were conducted at temperatures of 30, 55 and 80°C, soaking time of 60, 120 and 180 min using acidified methanol solvent with different trifluoroacetic acid (TFA) contents of 0.5, 1.75 and 3% (v/v). The statistical evaluation was performed by running analysis of variance (ANOVA) and regression calculation to investigate the significance of the generated model. Results show that the generated regression models adequately explain the data variation and significantly represented the actual relationship between the independent variables and the responses. Analysis of variance (ANOVA) showed high coefficient determination values (R2) of 0.9687 for a*, 0.9621 for b* and 0.9758 for color saturation, thus ensuring a satisfactory fit of the developed models with the experimental data. Interaction between TFA content and extraction temperature exhibited to the highest significant influence on CIE color parameter.

Additional extensions to the NASCAP computer code, volume 2

NASA Technical Reports Server (NTRS)

Stannard, P. R.; Katz, I.; Mandell, M. J.

1982-01-01

Particular attention is given to comparison of the actural response of the SCATHA (Spacecraft Charging AT High Altitudes) P78-2 satellite with theoretical (NASCAP) predictions. Extensive comparisons for a variety of environmental conditions confirm the validity of the NASCAP model. A summary of the capabilities and range of validity of NASCAP is presented, with extensive reference to previously published applications. It is shown that NASCAP is capable of providing quantitatively accurate results when the object and environment are adequately represented and fall within the range of conditions for which NASCAP was intended. Three dimensional electric field affects play an important role in determining the potential of dielectric surfaces and electrically isolated conducting surfaces, particularly in the presence of artificially imposed high voltages. A theory for such phenomena is presented and applied to the active control experiments carried out in SCATHA, as well as other space and laboratory experiments. Finally, some preliminary work toward modeling large spacecraft in polar Earth orbit is presented. An initial physical model is presented including charge emission. A simple code based upon the model is described along with code test results.

A soft X-ray map of the Perseus cluster of galaxies

NASA Technical Reports Server (NTRS)

Cash, W.; Malina, R. F.; Wolff, R. S.

1976-01-01

A 0.5-3-keV X-ray map of the Perseus cluster of galaxies is presented. The map shows a region of strong emission centered near NGC 1275 plus a highly elongated emission region which lies along the line of bright galaxies that dominates the core of the cluster. The data are compared with various models that include point and diffuse sources. One model which adequately represents the data is the superposition of a point source at NGC 1275 and an isothermal ellipsoid resulting from the bremsstrahlung emission of cluster gas. The ellipsoid has a major core radius of 20.5 arcmin and a minor core radius of 5.5 arcmin, consistent with the values obtained from galaxy counts. All acceptable models provide evidence for a compact source (less than 3 arcmin FWHM) at NGC 1275 containing about 25% of the total emission. Since the diffuse X-ray and radio components have radically different morphologies, it is unlikely that the emissions arise from a common source, as proposed in inverse-Compton models.

DYNA3D/ParaDyn Regression Test Suite Inventory

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

Lin, Jerry I.

2016-09-01

The following table constitutes an initial assessment of feature coverage across the regression test suite used for DYNA3D and ParaDyn. It documents the regression test suite at the time of preliminary release 16.1 in September 2016. The columns of the table represent groupings of functionalities, e.g., material models. Each problem in the test suite is represented by a row in the table. All features exercised by the problem are denoted by a check mark (√) in the corresponding column. The definition of “feature” has not been subdivided to its smallest unit of user input, e.g., algorithmic parameters specific to amore » particular type of contact surface. This represents a judgment to provide code developers and users a reasonable impression of feature coverage without expanding the width of the table by several multiples. All regression testing is run in parallel, typically with eight processors, except problems involving features only available in serial mode. Many are strictly regression tests acting as a check that the codes continue to produce adequately repeatable results as development unfolds; compilers change and platforms are replaced. A subset of the tests represents true verification problems that have been checked against analytical or other benchmark solutions. Users are welcomed to submit documented problems for inclusion in the test suite, especially if they are heavily exercising, and dependent upon, features that are currently underrepresented.« less

Representing culture in interstellar messages

NASA Astrophysics Data System (ADS)

Vakoch, Douglas A.

2008-09-01

As scholars involved with the Search for Extraterrestrial Intelligence (SETI) have contemplated how we might portray humankind in any messages sent to civilizations beyond Earth, one of the challenges they face is adequately representing the diversity of human cultures. For example, in a 2003 workshop in Paris sponsored by the SETI Institute, the International Academy of Astronautics (IAA) SETI Permanent Study Group, the International Society for the Arts, Sciences and Technology (ISAST), and the John Templeton Foundation, a varied group of artists, scientists, and scholars from the humanities considered how to encode notions of altruism in interstellar messages . Though the group represented 10 countries, most were from Europe and North America, leading to the group's recommendation that subsequent discussions on the topic should include more globally representative perspectives. As a result, the IAA Study Group on Interstellar Message Construction and the SETI Institute sponsored a follow-up workshop in Santa Fe, New Mexico, USA in February 2005. The Santa Fe workshop brought together scholars from a range of disciplines including anthropology, archaeology, chemistry, communication science, philosophy, and psychology. Participants included scholars familiar with interstellar message design as well as specialists in cross-cultural research who had participated in the Symposium on Altruism in Cross-cultural Perspective, held just prior to the workshop during the annual conference of the Society for Cross-cultural Research . The workshop included discussion of how cultural understandings of altruism can complement and critique the more biologically based models of altruism proposed for interstellar messages at the 2003 Paris workshop. This paper, written by the chair of both the Paris and Santa Fe workshops, will explore the challenges of communicating concepts of altruism that draw on both biological and cultural models.

The use of discrete-event simulation modeling to compare handwritten and electronic prescribing systems.

PubMed

Ghany, Ahmad; Vassanji, Karim; Kuziemsky, Craig; Keshavjee, Karim

2013-01-01

Electronic prescribing (e-prescribing) is expected to bring many benefits to Canadian healthcare, such as a reduction in errors and adverse drug reactions. As there currently is no functioning e-prescribing system in Canada that is completely electronic, we are unable to evaluate the performance of a live system. An alternative approach is to use simulation modeling for evaluation. We developed two discrete-event simulation models, one of the current handwritten prescribing system and one of a proposed e-prescribing system, to compare the performance of these two systems. We were able to compare the number of processes in each model, workflow efficiency, and the distribution of patients or prescriptions. Although we were able to compare these models to each other, using discrete-event simulation software was challenging. We were limited in the number of variables we could measure. We discovered non-linear processes and feedback loops in both models that could not be adequately represented using discrete-event simulation software. Finally, interactions between entities in both models could not be modeled using this type of software. We have come to the conclusion that a more appropriate approach to modeling both the handwritten and electronic prescribing systems would be to use a complex adaptive systems approach using agent-based modeling or systems-based modeling.

Civil war and child health: regional and ethnic dimensions of child immunization and malnutrition in Angola.

PubMed

Agadjanian, Victor; Prata, Ndola

2003-06-01

This study arises from a general proposition that different levels and types of exposure to war are crucial in shaping health outcomes in a population under war-induced duress. We analyze civil war-related regional and ethnolinguistic differentials in age-adequate immunization (complete vaccination for age) and levels of malnutrition in Angola. Our analysis is based on data from a nationally representative survey conducted in 1996, some 2 years after the end of one of the most destructive periods of hostilities in the history of Angolan civil war. The data show that despite Angola's unique mineral wealth, the nation's levels of child age-adequate immunization is lower and malnutrition rates are higher than in most of sub-Saharan Africa. To examine age-adequate immunization and chronic malnutrition we fit logistic regression models that include the regional degree of war impact and ethnolinguistic group, in addition to rural-urban differences and other conventional sociodemographic characteristics. The tests reveal a significant disadvantage of rural children relative to urban children in both immunization and chronic malnutrition. Net of the rural-urban differences, we also detect a significant disadvantage of children residing in parts of the country that had been most affected by the fighting. The tests also point to a lower level of immunization and higher level of chronic malnutrition among children from the ethnolinguistic group commonly identified with the opposition. These associations tend to be stronger among children who were born and/or grew up during war than among children who were born after peace was re-established.

The Quest for Comparability: Studying the Invariance of the Teachers’ Sense of Self-Efficacy (TSES) Measure across Countries

PubMed Central

Scherer, Ronny; Jansen, Malte; Nilsen, Trude; Areepattamannil, Shaljan; Marsh, Herbert W.

2016-01-01

Teachers’ self-efficacy is an important motivational construct that is positively related to a variety of outcomes for both the teachers and their students. This study addresses challenges associated with the commonly used ‘Teachers’ Sense of Self-Efficacy (TSES)’ measure across countries and provides a synergism between substantive research on teachers’ self-efficacy and the novel methodological approach of exploratory structural equation modeling (ESEM). These challenges include adequately representing the conceptual overlap between the facets of self-efficacy in a measurement model (cross-loadings) and comparing means and factor structures across countries (measurement invariance). On the basis of the OECD Teaching and Learning International Survey (TALIS) 2013 data set comprising 32 countries (N = 164,687), we investigate the effects of cross-loadings in the TSES measurement model on the results of measurement invariance testing and the estimation of relations to external constructs (i.e., working experience, job satisfaction). To further test the robustness of our results, we replicate the 32-countries analyses for three selected sub-groups of countries (i.e., Nordic, East and South-East Asian, and Anglo-Saxon country clusters). For each of the TALIS 2013 participating countries, we found that the factor structure of the self-efficacy measure is better represented by ESEM than by confirmatory factor analysis (CFA) models that do not allow for cross-loadings. For both ESEM and CFA, only metric invariance could be achieved. Nevertheless, invariance levels beyond metric invariance are better achieved with ESEM within selected country clusters. Moreover, the existence of cross-loadings did not affect the relations between the dimensions of teachers’ self-efficacy and external constructs. Overall, this study shows that a conceptual overlap between the facets of self-efficacy exists and can be well-represented by ESEM. We further argue for the cross-cultural generalizability of the corresponding measurement model. PMID:26959236

The Quest for Comparability: Studying the Invariance of the Teachers' Sense of Self-Efficacy (TSES) Measure across Countries.

PubMed

Scherer, Ronny; Jansen, Malte; Nilsen, Trude; Areepattamannil, Shaljan; Marsh, Herbert W

2016-01-01

Teachers' self-efficacy is an important motivational construct that is positively related to a variety of outcomes for both the teachers and their students. This study addresses challenges associated with the commonly used 'Teachers' Sense of Self-Efficacy (TSES)' measure across countries and provides a synergism between substantive research on teachers' self-efficacy and the novel methodological approach of exploratory structural equation modeling (ESEM). These challenges include adequately representing the conceptual overlap between the facets of self-efficacy in a measurement model (cross-loadings) and comparing means and factor structures across countries (measurement invariance). On the basis of the OECD Teaching and Learning International Survey (TALIS) 2013 data set comprising 32 countries (N = 164,687), we investigate the effects of cross-loadings in the TSES measurement model on the results of measurement invariance testing and the estimation of relations to external constructs (i.e., working experience, job satisfaction). To further test the robustness of our results, we replicate the 32-countries analyses for three selected sub-groups of countries (i.e., Nordic, East and South-East Asian, and Anglo-Saxon country clusters). For each of the TALIS 2013 participating countries, we found that the factor structure of the self-efficacy measure is better represented by ESEM than by confirmatory factor analysis (CFA) models that do not allow for cross-loadings. For both ESEM and CFA, only metric invariance could be achieved. Nevertheless, invariance levels beyond metric invariance are better achieved with ESEM within selected country clusters. Moreover, the existence of cross-loadings did not affect the relations between the dimensions of teachers' self-efficacy and external constructs. Overall, this study shows that a conceptual overlap between the facets of self-efficacy exists and can be well-represented by ESEM. We further argue for the cross-cultural generalizability of the corresponding measurement model.

Pre-clinical methods for detecting the hypersensitivity potential of pharmaceuticals: regulatory considerations.

PubMed

Hastings, K L

2001-02-02

Immune-based systemic hypersensitivities account for a significant number of adverse drug reactions. There appear to be no adequate nonclinical models to predict systemic hypersensitivity to small molecular weight drugs. Although there are very good methods for detecting drugs that can induce contact sensitization, these have not been successfully adapted for prediction of systemic hypersensitivity. Several factors have made the development of adequate models difficult. The term systemic hypersensitivity encompases many discrete immunopathologies. Each type of immunopathology presumably is the result of a specific cluster of immunologic and biochemical phenomena. Certainly other factors, such as genetic predisposition, metabolic idiosyncrasies, and concomitant diseases, further complicate the problem. Therefore, it may be difficult to find common mechanisms upon which to construct adequate models to predict specific types of systemic hypersensitivity reactions. There is some reason to hope, however, that adequate methods could be developed for at least identifying drugs that have the potential to produce signs indicative of a general hazard for immune-based reactions.

One size does not fit all: an examination of low birthweight disparities among a diverse set of racial/ethnic groups.

PubMed

Johnelle Sparks, P

2009-11-01

To examine disparities in low birthweight using a diverse set of racial/ethnic categories and a nationally representative sample. This research explored the degree to which sociodemographic characteristics, health care access, maternal health status, and health behaviors influence birthweight disparities among seven racial/ethnic groups. Binary logistic regression models were estimated using a nationally representative sample of singleton, normal for gestational age births from 2001 using the ECLS-B, which has an approximate sample size of 7,800 infants. The multiple variable models examine disparities in low birthweight (LBW) for seven racial/ethnic groups, including non-Hispanic white, non-Hispanic black, U.S.-born Mexican-origin Hispanic, foreign-born Mexican-origin Hispanic, other Hispanic, Native American, and Asian mothers. Race-stratified logistic regression models were also examined. In the full sample models, only non-Hispanic black mothers have a LBW disadvantage compared to non-Hispanic white mothers. Maternal WIC usage was protective against LBW in the full models. No prenatal care and adequate plus prenatal care increase the odds of LBW. In the race-stratified models, prenatal care adequacy and high maternal health risks are the only variables that influence LBW for all racial/ethnic groups. The race-stratified models highlight the different mechanism important across the racial/ethnic groups in determining LBW. Differences in the distribution of maternal sociodemographic, health care access, health status, and behavior characteristics by race/ethnicity demonstrate that a single empirical framework may distort associations with LBW for certain racial and ethnic groups. More attention must be given to the specific mechanisms linking maternal risk factors to poor birth outcomes for specific racial/ethnic groups.

Projected changes in medicanes in the HadGEM3 N512 high-resolution global climate model

NASA Astrophysics Data System (ADS)

Tous, M.; Zappa, G.; Romero, R.; Shaffrey, L.; Vidale, P. L.

2016-09-01

Medicanes or "Mediterranean hurricanes" represent a rare and physically unique type of Mediterranean mesoscale cyclone. There are similarities with tropical cyclones with regard to their development (based on the thermodynamical disequilibrium between the warm sea and the overlying troposphere) and their kinematic and thermodynamical properties (medicanes are intense vortices with a warm core and even a cloud-free eye). Although medicanes are smaller and their wind speeds are lower than in tropical cyclones, the severity of their winds can cause substantial damage to islands and coastal areas. Concern about how human-induced climate change will affect extreme events is increasing. This includes the future impacts on medicanes due to the warming of the Mediterranean waters and the projected changes in regional atmospheric circulation. However, most global climate models do not have high enough spatial resolution to adequately represent small features such as medicanes. In this study, a cyclone tracking algorithm is applied to high resolution global climate model data with a horizontal grid resolution of approximately 25 km over the Mediterranean region. After a validation of the climatology of general Mediterranean mesoscale cyclones, changes in medicanes are determined using climate model experiments with present and future forcing. The magnitude of the changes in the winds, frequency and location of medicanes is assessed. While no significant changes in the total number of Mediterranean mesoscale cyclones are found, medicanes tend to decrease in number but increase in intensity. The model simulation suggests that medicanes tend to form more frequently in the Gulf of Lion-Genoa and South of Sicily.

The median problems on linear multichromosomal genomes: graph representation and fast exact solutions.

PubMed

Xu, Andrew Wei

2010-09-01

In genome rearrangement, given a set of genomes G and a distance measure d, the median problem asks for another genome q that minimizes the total distance [Formula: see text]. This is a key problem in genome rearrangement based phylogenetic analysis. Although this problem is known to be NP-hard, we have shown in a previous article, on circular genomes and under the DCJ distance measure, that a family of patterns in the given genomes--represented by adequate subgraphs--allow us to rapidly find exact solutions to the median problem in a decomposition approach. In this article, we extend this result to the case of linear multichromosomal genomes, in order to solve more interesting problems on eukaryotic nuclear genomes. A multi-way capping problem in the linear multichromosomal case imposes an extra computational challenge on top of the difficulty in the circular case, and this difficulty has been underestimated in our previous study and is addressed in this article. We represent the median problem by the capped multiple breakpoint graph, extend the adequate subgraphs into the capped adequate subgraphs, and prove optimality-preserving decomposition theorems, which give us the tools to solve the median problem and the multi-way capping optimization problem together. We also develop an exact algorithm ASMedian-linear, which iteratively detects instances of (capped) adequate subgraphs and decomposes problems into subproblems. Tested on simulated data, ASMedian-linear can rapidly solve most problems with up to several thousand genes, and it also can provide optimal or near-optimal solutions to the median problem under the reversal/HP distance measures. ASMedian-linear is available at http://sites.google.com/site/andrewweixu .

Virtual Guidance Ultrasound: A Tool to Obtain Diagnostic Ultrasound for Remote Environments

NASA Technical Reports Server (NTRS)

Caine,Timothy L.; Martin David S.; Matz, Timothy; Lee, Stuart M. C.; Stenger, Michael B.; Platts, Steven H.

2012-01-01

Astronauts currently acquire ultrasound images on the International Space Station with the assistance of real-time remote guidance from an ultrasound expert in Mission Control. Remote guidance will not be feasible when significant communication delays exist during exploration missions beyond low-Earth orbit. For example, there may be as much as a 20- minute delay in communications between the Earth and Mars. Virtual-guidance, a pre-recorded audio-visual tutorial viewed in real-time, is a viable modality for minimally trained scanners to obtain diagnostically-adequate images of clinically relevant anatomical structures in an autonomous manner. METHODS: Inexperienced ultrasound operators were recruited to perform carotid artery (n = 10) and ophthalmic (n = 9) ultrasound examinations using virtual guidance as their only instructional tool. In the carotid group, each each untrained operator acquired two-dimensional, pulsed, and color Doppler of the carotid artery. In the ophthalmic group, operators acquired representative images of the anterior chamber of the eye, retina, optic nerve, and nerve sheath. Ultrasound image quality was evaluated by independent imaging experts. RESULTS: Eight of the 10 carotid studies were judged to be diagnostically adequate. With one exception the quality of all the ophthalmic images were adequate to excellent. CONCLUSION: Diagnostically-adequate carotid and ophthalmic ultrasound examinations can be obtained by untrained operators with instruction only from an audio/video tutorial viewed in real time while scanning. This form of quick-response-guidance, can be developed for other ultrasound examinations, represents an opportunity to acquire important medical and scientific information for NASA flight surgeons and researchers when trained medical personnel are not present. Further, virtual guidance will allow untrained personnel to autonomously obtain important medical information in remote locations on Earth where communication is difficult or absent.

THE IMPACT OF NEONATAL BREASTFEEDING ON GROWTH TRAJECTORIES OF YOUTH EXPOSED AND UNEXPOSED TO DIABETES IN UTERO: THE EPOCH STUDY

PubMed Central

Crume, T.L.; Ogden, L.G.; Mayer-Davis, E.J.; Hamman, R.F.; Norris, J.M.; Bischoff, K.J.; McDuffie, R.; Dabelea, D.

2011-01-01

Objective To evaluate the influence of breastfeeding on the body mass index (BMI) growth trajectory from birth through 13 years of age among offspring of diabetic pregnancies (ODP) and offspring of non-diabetic pregnancies (ONDP) participating in the EPOCH study. Subjects There were 94 ODP and 399 ONDP who had multiple BMI measures obtained from birth throughout childhood. A measure of breast milk-months was derived from maternal self-report to categorize breastfeeding status as adequate (≥6 breast milk-months) or low (<6 breast milk-months). Mixed linear effects models were constructed to assess the impact of breastfeeding on the BMI growth curves during infancy (birth to 27 months) and childhood (27 months to 13 years). Results ODP who were adequately breastfed had a slower BMI growth trajectory during childhood (p=0.047) and slower period-specific growth velocity with significant differences between 4 to 6 years of age (p=0.03) and 6 to 9 years of age (p=0.01) compared to ODP with low breastfeeding. A similar pattern was seen in the ONDP, with adequate breastfeeding associated with lower average BMI in infancy (p=0.03) and childhood (p=0.0002) and a slower growth trajectory in childhood (p=0.0002). Slower period-specific growth velocity was seen among the ONDP associated with adequate breastfeeding with significant differences between 12–26 months (p=0.02), 4–6 years (p=0.03), 6–9 years (p=0.0001) and 9–13 years of age (p<.0001). Conclusion Our study provides novel evidence that breastfeeding is associated with long-term effects on childhood BMI growth that extend beyond infancy into early and late childhood. Importantly, these effects are also present in the high-risk offspring, exposed to overnutrition during pregnancy. Breastfeeding in the early postnatal period may represent a critical opportunity to reduce the risk of childhood obesity. PMID:22290537

Simple stochastic birth and death models of genome evolution: was there enough time for us to evolve?

PubMed

Karev, Georgy P; Wolf, Yuri I; Koonin, Eugene V

2003-10-12

The distributions of many genome-associated quantities, including the membership of paralogous gene families can be approximated with power laws. We are interested in developing mathematical models of genome evolution that adequately account for the shape of these distributions and describe the evolutionary dynamics of their formation. We show that simple stochastic models of genome evolution lead to power-law asymptotics of protein domain family size distribution. These models, called Birth, Death and Innovation Models (BDIM), represent a special class of balanced birth-and-death processes, in which domain duplication and deletion rates are asymptotically equal up to the second order. The simplest, linear BDIM shows an excellent fit to the observed distributions of domain family size in diverse prokaryotic and eukaryotic genomes. However, the stochastic version of the linear BDIM explored here predicts that the actual size of large paralogous families is reached on an unrealistically long timescale. We show that introduction of non-linearity, which might be interpreted as interaction of a particular order between individual family members, allows the model to achieve genome evolution rates that are much better compatible with the current estimates of the rates of individual duplication/loss events.

Parameterizing the Morse Potential for Coarse-Grained Modeling of Blood Plasma

PubMed Central

Zhang, Na; Zhang, Peng; Kang, Wei; Bluestein, Danny; Deng, Yuefan

2014-01-01

Multiscale simulations of fluids such as blood represent a major computational challenge of coupling the disparate spatiotemporal scales between molecular and macroscopic transport phenomena characterizing such complex fluids. In this paper, a coarse-grained (CG) particle model is developed for simulating blood flow by modifying the Morse potential, traditionally used in Molecular Dynamics for modeling vibrating structures. The modified Morse potential is parameterized with effective mass scales for reproducing blood viscous flow properties, including density, pressure, viscosity, compressibility and characteristic flow dynamics of human blood plasma fluid. The parameterization follows a standard inverse-problem approach in which the optimal micro parameters are systematically searched, by gradually decoupling loosely correlated parameter spaces, to match the macro physical quantities of viscous blood flow. The predictions of this particle based multiscale model compare favorably to classic viscous flow solutions such as Counter-Poiseuille and Couette flows. It demonstrates that such coarse grained particle model can be applied to replicate the dynamics of viscous blood flow, with the advantage of bridging the gap between macroscopic flow scales and the cellular scales characterizing blood flow that continuum based models fail to handle adequately. PMID:24910470

Experimental Verification of Modeled Thermal Distribution Produced by a Piston Source in Physiotherapy Ultrasound

PubMed Central

Lopez-Haro, S. A.; Leija, L.

2016-01-01

Objectives. To present a quantitative comparison of thermal patterns produced by the piston-in-a-baffle approach with those generated by a physiotherapy ultrasonic device and to show the dependency among thermal patterns and acoustic intensity distributions. Methods. The finite element (FE) method was used to model an ideal acoustic field and the produced thermal pattern to be compared with the experimental acoustic and temperature distributions produced by a real ultrasonic applicator. A thermal model using the measured acoustic profile as input is also presented for comparison. Temperature measurements were carried out with thermocouples inserted in muscle phantom. The insertion place of thermocouples was monitored with ultrasound imaging. Results. Modeled and measured thermal profiles were compared within the first 10 cm of depth. The ideal acoustic field did not adequately represent the measured field having different temperature profiles (errors 10% to 20%). Experimental field was concentrated near the transducer producing a region with higher temperatures, while the modeled ideal temperature was linearly distributed along the depth. The error was reduced to 7% when introducing the measured acoustic field as the input variable in the FE temperature modeling. Conclusions. Temperature distributions are strongly related to the acoustic field distributions. PMID:27999801

Assessing and correcting spatial representativeness of tower eddy-covariance flux measurements

NASA Astrophysics Data System (ADS)

Metzger, S.; Xu, K.; Desai, A. R.; Taylor, J. R.; Kljun, N.; Blanken, P.; Burns, S. P.; Scott, R. L.

2014-12-01

Estimating the landscape-scale exchange of ecologically relevant trace gas and energy fluxes from tower eddy-covariance (EC) measurements is often complicated by surface heterogeneity. For example, a tower EC measurement may represent less than 1% of a grid cell resolved by mechanistic models (order 100-1000 km2). In particular for data assimilation or comparison with large-scale observations, it is hence critical to assess and correct the spatial representativeness of tower EC measurements. We present a procedure that determines from a single EC tower the spatio-temporally explicit flux field of its surrounding. The underlying principle is to extract the relationship between biophysical drivers and ecological responses from measurements under varying environmental conditions. For this purpose, high-frequency EC flux processing and source area calculations (≈60 h-1) are combined with remote sensing retrievals of land surface properties and subsequent machine learning. Methodological details are provided in our companion presentation "Towards the spatial rectification of tower-based eddy-covariance flux observations". We apply the procedure to one year of data from each of four AmeriFlux sites under different climate and ecological environments: Lost Creek shrub fen wetland, Niwot Ridge subalpine conifer, Park Falls mixed forest, and Santa Rita mesquite savanna. We find that heat fluxes from the Park Falls 122-m-high EC measurement and from a surrounding 100 km2 target area differ up to 100 W m-2, or 65%. Moreover, 85% and 24% of the EC flux observations are adequate surrogates of the mean surface-atmosphere exchange and its spatial variability across a 900 km2 target area, respectively, at 5% significance and 80% representativeness levels. Alternatively, the resulting flux grids can be summarized as probability density functions, and used to inform mechanistic models directly with the mean flux value and its spatial variability across a model grid cell. Lastly, for each site we evaluate the applicability of the procedure based on a full bottom-up uncertainty budget.

Sensor Data Fusion with Z-Numbers and Its Application in Fault Diagnosis

PubMed Central

Jiang, Wen; Xie, Chunhe; Zhuang, Miaoyan; Shou, Yehang; Tang, Yongchuan

2016-01-01

Sensor data fusion technology is widely employed in fault diagnosis. The information in a sensor data fusion system is characterized by not only fuzziness, but also partial reliability. Uncertain information of sensors, including randomness, fuzziness, etc., has been extensively studied recently. However, the reliability of a sensor is often overlooked or cannot be analyzed adequately. A Z-number, Z = (A, B), can represent the fuzziness and the reliability of information simultaneously, where the first component A represents a fuzzy restriction on the values of uncertain variables and the second component B is a measure of the reliability of A. In order to model and process the uncertainties in a sensor data fusion system reasonably, in this paper, a novel method combining the Z-number and Dempster–Shafer (D-S) evidence theory is proposed, where the Z-number is used to model the fuzziness and reliability of the sensor data and the D-S evidence theory is used to fuse the uncertain information of Z-numbers. The main advantages of the proposed method are that it provides a more robust measure of reliability to the sensor data, and the complementary information of multi-sensors reduces the uncertainty of the fault recognition, thus enhancing the reliability of fault detection. PMID:27649193

Simulation of advective flow under steady-state and transient recharge conditions, Camp Edwards, Massachusetts Military Reservation, Cape Cod, Massachusetts

USGS Publications Warehouse

Walter, Donald A.; Masterson, John P.

2003-01-01

The U.S. Geological Survey has developed several ground-water models in support of an investigation of ground-water contamination being conducted by the Army National Guard Bureau at Camp Edwards, Massachusetts Military Reservation on western Cape Cod, Massachusetts. Regional and subregional steady-state models and regional transient models were used to (1) improve understanding of the hydrologic system, (2) simulate advective transport of contaminants, (3) delineate recharge areas to municipal wells, and (4) evaluate how model discretization and time-varying recharge affect simulation results. A water-table mound dominates ground-water-flow patterns. Near the top of the mound, which is within Camp Edwards, hydraulic gradients are nearly vertically downward and horizontal gradients are small. In downgradient areas that are further from the top of the water-table mound, the ratio of horizontal to vertical gradients is larger and horizontal flow predominates. The steady-state regional model adequately simulates advective transport in some areas of the aquifer; however, simulation of ground-water flow in areas with local hydrologic boundaries, such as ponds, requires more finely discretized subregional models. Subregional models also are needed to delineate recharge areas to municipal wells that are inadequately represented in the regional model or are near other pumped wells. Long-term changes in recharge rates affect hydraulic heads in the aquifer and shift the position of the top of the water-table mound. Hydraulic-gradient directions do not change over time in downgradient areas, whereas they do change substantially with temporal changes in recharge near the top of the water-table mound. The assumption of steady-state hydraulic conditions is valid in downgradient area, where advective transport paths change little over time. In areas closer to the top of the water-table mound, advective transport paths change as a function of time, transient and steady-state paths do not coincide, and the assumption of steady-state conditions is not valid. The simulation results indicate that several modeling tools are needed to adequately simulate ground-water flow at the site and that the utility of a model varies according to hydrologic conditions in the specific areas of interest.

Experimental use of high density polyethylene drainage pipe as a cross roadway drainage structure.

DOT National Transportation Integrated Search

2001-01-01

Adequate drainage is one of the most important requirements in the reconstruction of a highway. Often it represents an appreciable expense of construction. In some applications installation costs may be reduced by the use of lighter weight drainage p...

The Student Affairs Committee. Effective Committees. Board Basics.

ERIC Educational Resources Information Center

Goodale, Thomas G.

1997-01-01

Responsibilities of the college or university governing board's student affairs committee include representing students' interests in all policy decisions, ensuring provision of adequate financial resources to support a comprehensive student affairs program, ensuring that board policies keep pace with students' diverse and changing needs, and…

Can Cultural Worldviews Influence Network Composition?

ERIC Educational Resources Information Center

Vaisey, Stephen; Lizardo, Omar

2010-01-01

Most sociological research assumes that social network composition shapes individual beliefs. Network theory and research has not adequately considered that internalized cultural worldviews might affect network composition. Drawing on a synthetic, dual-process theory of culture and two waves of nationally-representative panel data, this article…

Knowledge, attitude and practice of mammography among women users of public health services.

PubMed

Marinho, Luiz Alberto Barcelos; Cecatti, José Guilherme; Osis, Maria José Duarte; Gurgel, Maria Salete Costa

2008-04-01

To evaluate knowledge, attitude and practice related to mammography among women users of local health services, identifying barriers to its performance. A total of 663 women were interviewed at 13 local health centers in a city of Southeastern Brazil, in 2001. Interviewees were randomly selected at each center and they were representative from different socioeconomic conditions. The number of interviewees at each center was proportional to monthly mean appointments. For data analysis, answers were described as knowledge, attitude, practice and their respective adequacies and then they were correlated with control variables through the chi-square test. Only 7.4% of the interviewees had adequate knowledge on mammography, while 97.1% of women had an adequate attitude. The same was seen for the practice of mammography that was adequate in 35.7% of the cases. The main barrier to mammography was lack of referral by physicians working at the health center (81.8%). There was an association between adequacy of attitude and five years or more of education and being married. There was also an association between adequacy of mammography practice and being employed and family income up to four minimum wages. Women users of local health services had no adequate knowledge and practice related to mammography despite having an adequate attitude about this exam.

Ankle Joint Intrinsic Dynamics is More Complex than a Mass-Spring-Damper Model.

PubMed

Sobhani Tehrani, Ehsan; Jalaleddini, Kian; Kearney, Robert E

2017-09-01

This paper describes a new small signal parametric model of ankle joint intrinsic mechanics in normal subjects. We found that intrinsic ankle mechanics is a third-order system and the second-order mass-spring-damper model, referred to as IBK, used by many researchers in the literature cannot adequately represent ankle dynamics at all frequencies in a number of important tasks. This was demonstrated using experimental data from five healthy subjects with no voluntary muscle contraction and at seven ankle positions covering the range of motion. We showed that the difference between the new third-order model and the conventional IBK model increased from dorsi to plantarflexed position. The new model was obtained using a multi-step identification procedure applied to experimental input/output data of the ankle joint. The procedure first identifies a non-parametric model of intrinsic joint stiffness where ankle position is the input and torque is the output. Then, in several steps, the model is converted into a continuous-time transfer function of ankle compliance, which is the inverse of stiffness. Finally, we showed that the third-order model is indeed structurally consistent with agonist-antagonist musculoskeletal structure of human ankle, which is not the case for the IBK model.

Interpretation of environmental tracers in groundwater systems with stagnant water zones.

PubMed

Maloszewski, Piotr; Stichler, Willibald; Zuber, Andrzej

2004-03-01

Lumped-parameter models are commonly applied for determining the age of water from time records of transient environmental tracers. The simplest models (e.g. piston flow or exponential) are also applicable for dating based on the decay or accumulation of tracers in groundwater systems. The models are based on the assumption that the transit time distribution function (exit age distribution function) of the tracer particles in the investigated system adequately represents the distribution of flow lines and is described by a simple function. A chosen or fitted function (called the response function) describes the transit time distribution of a tracer which would be observed at the output (discharge area, spring, stream, or pumping wells) in the case of an instantaneous injection at the entrance (recharge area). Due to large space and time scales, response functions are not measurable in groundwater systems, therefore, functions known from other fields of science, mainly from chemical engineering, are usually used. The type of response function and the values of its parameters define the lumped-parameter model of a system. The main parameter is the mean transit time of tracer through the system, which under favourable conditions may represent the mean age of mobile water. The parameters of the model are found by fitting calculated concentrations to the experimental records of concentrations measured at the outlet. The mean transit time of tracer (often called the tracer age), whether equal to the mean age of water or not, serves in adequate combinations with other data for determining other useful parameters, e.g. the recharge rate or the content of water in the system. The transit time distribution and its mean value serve for confirmation or determination of the conceptual model of the system and/or estimation of its potential vulnerability to anthropogenic pollution. In the interpretation of environmental tracer data with the aid of the lumped-parameter models, the influence of diffusion exchange between mobile water and stagnant or quasi-stagnant water is seldom considered, though it leads to large differences between tracer and water ages. Therefore, the article is focused on the transit time distribution functions of the most common lumped-parameter models, particularly those applicable for the interpretation of environmental tracer data in double-porosity aquifers, or aquifers in which aquitard diffusion may play an important role. A case study is recalled for a confined aquifer in which the diffusion exchange with aquitard most probably strongly influenced the transport of environmental tracers. Another case study presented is related to the interpretation of environmental tracer data obtained from lysimeters installed in the unsaturated zone with a fraction of stagnant water.

ESEA Reauthorization: Options for Improving NCLB's Measures of Process. Hearing before the Committee on Education and Labor, U.S. House of Representatives, One Hundred Tenth Congress, First Session (March 21, 2007). Serial Number 110-11

ERIC Educational Resources Information Center

US House of Representatives, 2007

2007-01-01

The purpose of this hearing was, review of the No Child Left Behind Law for reauthorization, consideration as to whether or not to reform the current definition of "Adequate Yearly Progress" (AYP). Members testifying before the Committee were the Hon. Jason Altmire, a Representative in Congress from the State of Pennsylvania; Hon. Howard…

Using argument notation to engineer biological simulations with increased confidence

PubMed Central

Alden, Kieran; Andrews, Paul S.; Polack, Fiona A. C.; Veiga-Fernandes, Henrique; Coles, Mark C.; Timmis, Jon

2015-01-01

The application of computational and mathematical modelling to explore the mechanics of biological systems is becoming prevalent. To significantly impact biological research, notably in developing novel therapeutics, it is critical that the model adequately represents the captured system. Confidence in adopting in silico approaches can be improved by applying a structured argumentation approach, alongside model development and results analysis. We propose an approach based on argumentation from safety-critical systems engineering, where a system is subjected to a stringent analysis of compliance against identified criteria. We show its use in examining the biological information upon which a model is based, identifying model strengths, highlighting areas requiring additional biological experimentation and providing documentation to support model publication. We demonstrate our use of structured argumentation in the development of a model of lymphoid tissue formation, specifically Peyer's Patches. The argumentation structure is captured using Artoo (www.york.ac.uk/ycil/software/artoo), our Web-based tool for constructing fitness-for-purpose arguments, using a notation based on the safety-critical goal structuring notation. We show how argumentation helps in making the design and structured analysis of a model transparent, capturing the reasoning behind the inclusion or exclusion of each biological feature and recording assumptions, as well as pointing to evidence supporting model-derived conclusions. PMID:25589574

Using argument notation to engineer biological simulations with increased confidence.

PubMed

Alden, Kieran; Andrews, Paul S; Polack, Fiona A C; Veiga-Fernandes, Henrique; Coles, Mark C; Timmis, Jon

2015-03-06

The application of computational and mathematical modelling to explore the mechanics of biological systems is becoming prevalent. To significantly impact biological research, notably in developing novel therapeutics, it is critical that the model adequately represents the captured system. Confidence in adopting in silico approaches can be improved by applying a structured argumentation approach, alongside model development and results analysis. We propose an approach based on argumentation from safety-critical systems engineering, where a system is subjected to a stringent analysis of compliance against identified criteria. We show its use in examining the biological information upon which a model is based, identifying model strengths, highlighting areas requiring additional biological experimentation and providing documentation to support model publication. We demonstrate our use of structured argumentation in the development of a model of lymphoid tissue formation, specifically Peyer's Patches. The argumentation structure is captured using Artoo (www.york.ac.uk/ycil/software/artoo), our Web-based tool for constructing fitness-for-purpose arguments, using a notation based on the safety-critical goal structuring notation. We show how argumentation helps in making the design and structured analysis of a model transparent, capturing the reasoning behind the inclusion or exclusion of each biological feature and recording assumptions, as well as pointing to evidence supporting model-derived conclusions.

Improving finite element results in modeling heart valve mechanics.

PubMed

Earl, Emily; Mohammadi, Hadi

2018-06-01

Finite element analysis is a well-established computational tool which can be used for the analysis of soft tissue mechanics. Due to the structural complexity of the leaflet tissue of the heart valve, the currently available finite element models do not adequately represent the leaflet tissue. A method of addressing this issue is to implement computationally expensive finite element models, characterized by precise constitutive models including high-order and high-density mesh techniques. In this study, we introduce a novel numerical technique that enhances the results obtained from coarse mesh finite element models to provide accuracy comparable to that of fine mesh finite element models while maintaining a relatively low computational cost. Introduced in this study is a method by which the computational expense required to solve linear and nonlinear constitutive models, commonly used in heart valve mechanics simulations, is reduced while continuing to account for large and infinitesimal deformations. This continuum model is developed based on the least square algorithm procedure coupled with the finite difference method adhering to the assumption that the components of the strain tensor are available at all nodes of the finite element mesh model. The suggested numerical technique is easy to implement, practically efficient, and requires less computational time compared to currently available commercial finite element packages such as ANSYS and/or ABAQUS.

Quantifying and reducing model-form uncertainties in Reynolds-averaged Navier-Stokes simulations: A data-driven, physics-informed Bayesian approach

NASA Astrophysics Data System (ADS)

Xiao, H.; Wu, J.-L.; Wang, J.-X.; Sun, R.; Roy, C. J.

2016-11-01

Despite their well-known limitations, Reynolds-Averaged Navier-Stokes (RANS) models are still the workhorse tools for turbulent flow simulations in today's engineering analysis, design and optimization. While the predictive capability of RANS models depends on many factors, for many practical flows the turbulence models are by far the largest source of uncertainty. As RANS models are used in the design and safety evaluation of many mission-critical systems such as airplanes and nuclear power plants, quantifying their model-form uncertainties has significant implications in enabling risk-informed decision-making. In this work we develop a data-driven, physics-informed Bayesian framework for quantifying model-form uncertainties in RANS simulations. Uncertainties are introduced directly to the Reynolds stresses and are represented with compact parameterization accounting for empirical prior knowledge and physical constraints (e.g., realizability, smoothness, and symmetry). An iterative ensemble Kalman method is used to assimilate the prior knowledge and observation data in a Bayesian framework, and to propagate them to posterior distributions of velocities and other Quantities of Interest (QoIs). We use two representative cases, the flow over periodic hills and the flow in a square duct, to evaluate the performance of the proposed framework. Both cases are challenging for standard RANS turbulence models. Simulation results suggest that, even with very sparse observations, the obtained posterior mean velocities and other QoIs have significantly better agreement with the benchmark data compared to the baseline results. At most locations the posterior distribution adequately captures the true model error within the developed model form uncertainty bounds. The framework is a major improvement over existing black-box, physics-neutral methods for model-form uncertainty quantification, where prior knowledge and details of the models are not exploited. This approach has potential implications in many fields in which the governing equations are well understood but the model uncertainty comes from unresolved physical processes.

40 CFR 420.113 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2014 CFR

2014-07-01

... achievable (BAT). 420.113 Section 420.113 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... attainable by the application of the best available technology economically achievable (BAT). The Agency has... adequate control, the Agency is not promulgating more stringent BAT limitations. ...

40 CFR 420.113 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... achievable (BAT). 420.113 Section 420.113 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... attainable by the application of the best available technology economically achievable (BAT). The Agency has... adequate control, the Agency is not promulgating more stringent BAT limitations. ...

40 CFR 420.113 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2011 CFR

2011-07-01

... achievable (BAT). 420.113 Section 420.113 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... attainable by the application of the best available technology economically achievable (BAT). The Agency has... adequate control, the Agency is not promulgating more stringent BAT limitations. ...

40 CFR 420.113 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2012 CFR

2012-07-01

... achievable (BAT). 420.113 Section 420.113 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... attainable by the application of the best available technology economically achievable (BAT). The Agency has... adequate control, the Agency is not promulgating more stringent BAT limitations. ...

40 CFR 52.232 - Part D conditional approval.

Code of Federal Regulations, 2010 CFR

2010-07-01

... IX office). (ii) By January 1, 1981, a cutback asphalt rule which reflects reasonably available... SIP revision: (a) Adequate justification that the cutback asphalt rule represents RACT, (b) amendment of the cutback asphalt rule to conform with the controls recommended in the CTG document for cutback...

Context and Outcomes of Intercultural Education amongst International Students in Australia

ERIC Educational Resources Information Center

Zevallos, Zuleyka

2012-01-01

International students represent a large economic and international relations investment for Australia. Australian universities are increasingly relying upon overseas students for their revenue, but these institutions are not adequately addressing the special learning, linguistic, cultural and religious needs of these students. Despite their…

Further implications in analyzing contempt in modern society.

PubMed

Sternberg, Robert J

2017-01-01

The target article by Gervais & Fessler represents a comprehensive analysis of contempt but is not fully adequate in addressing how contempt produces hatred, how contempt is used manipulatively by aspiring leaders, and how contempt can be cured or at least mitigated. This commentary addresses these concerns.

Shadows of Music-Language Interaction on Low Frequency Brain Oscillatory Patterns

ERIC Educational Resources Information Center

Carrus, Elisa; Koelsch, Stefan; Bhattacharya, Joydeep

2011-01-01

Electrophysiological studies investigating similarities between music and language perception have relied exclusively on the signal averaging technique, which does not adequately represent oscillatory aspects of electrical brain activity that are relevant for higher cognition. The current study investigated the patterns of brain oscillations…

32 CFR 218.2 - General procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... approach taken in dose determination: (a) Use individual film badge data where available and complete, for... received estimate is made. (d) If partial film badge data are available, define group(s) of personnel with..., verify from the distribution of film badge readings whether the badged sample adequately represents the...

Sexual dysfunction within an adult developmental perspective.

PubMed

Fagan, P J; Meyer, J K; Schmidt, C W

1986-01-01

The focus of this paper is on the adult who has adequately mastered the oedipal stage of psychosexual development and who presents with a sexual dysfunction. Drawing on the developmental sequence of Erik Erikson, the authors suggest that failure to address adequately an adult psychosocial crisis may result in sexual dysfunction. There may be both adult developmental deficits and regression to adolescent and adult stages previously negotiated. Both may be symptomatically represented by sexual dysfunction. The authors urge that the sexual and marital problems be evaluated within an adult developmental framework and that the therapy address the psychosocial issues which are appropriate to the developmental stage of the patient.

Assessing Ecosystem Model Performance in Semiarid Systems

NASA Astrophysics Data System (ADS)

Thomas, A.; Dietze, M.; Scott, R. L.; Biederman, J. A.

2017-12-01

In ecosystem process modelling, comparing outputs to benchmark datasets observed in the field is an important way to validate models, allowing the modelling community to track model performance over time and compare models at specific sites. Multi-model comparison projects as well as models themselves have largely been focused on temperate forests and similar biomes. Semiarid regions, on the other hand, are underrepresented in land surface and ecosystem modelling efforts, and yet will be disproportionately impacted by disturbances such as climate change due to their sensitivity to changes in the water balance. Benchmarking models at semiarid sites is an important step in assessing and improving models' suitability for predicting the impact of disturbance on semiarid ecosystems. In this study, several ecosystem models were compared at a semiarid grassland in southwestern Arizona using PEcAn, or the Predictive Ecosystem Analyzer, an open-source eco-informatics toolbox ideal for creating the repeatable model workflows necessary for benchmarking. Models included SIPNET, DALEC, JULES, ED2, GDAY, LPJ-GUESS, MAESPA, CLM, CABLE, and FATES. Comparison between model output and benchmarks such as net ecosystem exchange (NEE) tended to produce high root mean square error and low correlation coefficients, reflecting poor simulation of seasonality and the tendency for models to create much higher carbon sources than observed. These results indicate that ecosystem models do not currently adequately represent semiarid ecosystem processes.

Towards an inventory of methane emissions from manure management that is responsive to changes on Canadian farms

NASA Astrophysics Data System (ADS)

VanderZaag, A. C.; MacDonald, J. D.; Evans, L.; Vergé, X. P. C.; Desjardins, R. L.

2013-09-01

Methane emissions from manure management represent an important mitigation opportunity, yet emission quantification methods remain crude and do not contain adequate detail to capture changes in agricultural practices that may influence emissions. Using the Canadian emission inventory methodology as an example, this letter explores three key aspects for improving emission quantification: (i) obtaining emission measurements to improve and validate emission model estimates, (ii) obtaining more useful activity data, and (iii) developing a methane emission model that uses the available farm management activity data. In Canada, national surveys to collect manure management data have been inconsistent and not designed to provide quantitative data. Thus, the inventory has not been able to accurately capture changes in management systems even between manure stored as solid versus liquid. To address this, we re-analyzed four farm management surveys from the past decade and quantified the significant change in manure management which can be linked to the annual agricultural survey to create a continuous time series. In the dairy industry of one province, for example, the percentage of manure stored as liquid increased by 300% between 1991 and 2006, which greatly affects the methane emission estimates. Methane emissions are greatest from liquid manure, but vary by an order of magnitude depending on how the liquid manure is managed. Even if more complete activity data are collected on manure storage systems, default Intergovernmental Panel on Climate Change (IPCC) guidance does not adequately capture the impacts of management decisions to reflect variation among farms and regions in inventory calculations. We propose a model that stays within the IPCC framework but would be more responsive to farm management by generating a matrix of methane conversion factors (MCFs) that account for key factors known to affect methane emissions: temperature, retention time and inoculum. This MCF matrix would be populated using a mechanistic emission model verified with on-farm emission measurements. Implementation of these MCF values will require re-analysis of farm surveys to quantify liquid manure emptying frequency and timing, and will rely on the continued collection of this activity data in the future. For model development and validation, emission measurement campaigns will be needed on representative farms over at least one full year, or manure management cycle (whichever is longer). The proposed approach described in this letter is long-term, but is required to establish baseline data for emissions from manure management systems. With these improvements, the manure management emission inventory will become more responsive to the changing practices on Canadian livestock farms.

Perspectives of UV nowcasting to monitor personal pro-health outdoor activities.

PubMed

Krzyścin, Janusz W; Lesiak, Aleksandra; Narbutt, Joanna; Sobolewski, Piotr; Guzikowski, Jakub

2018-07-01

Nowcasting model for online monitoring of personal outdoor behaviour is proposed. It is envisaged that it will provide an effective e-tool used by smartphone users. The model could estimate maximum duration of safe (without erythema risk) outdoor activity. Moreover, there are options to estimate duration of sunbathing to get adequate amount of vitamin D 3 and doses necessary for the antipsoriatic heliotherapy. The application requires information of starting time of sunbathing and the user's phototype. At the beginning the user will be informed of the approximate duration of sunbathing required to get the minimum erythemal dose, adequate amount of vitamin D 3 , and the dose necessary for the antipsoriatic heliotherapy. After every 20-min the application will recalculate the remaining duration of sunbathing based on the UVI measured in the preceding 20 min. If the estimate of remaining duration is <20 min the user will be informed that the deadline of sunbathing is approaching. Finally, a warning signal will be sent to stop sunbathing if the measured dose reaches the required dose. The proposed model is verified using the data collected at two measuring sites for the warm period of 2017 (1st April-30th September) in large Polish cities (Warsaw and Lodz). First instrument represents the UVI monitoring station. The information concerning sunbathing duration, which is sent to a remote user, is evaluated on the basis of the UVI measurements collected by the second measuring unit in a distance of ~7 km and 10 km for Warsaw and Lodz, respectively. The statistical analysis of the differences between sunbathing duration by nowcasting model and observation shows that the model provides reliable doses received by the users during outdoor activities in proximity (~10 km) to the UVI source site. Standard 24 h UVI forecast based on prognostic values of total ozone and cloudiness appears to only be valid for sunny days. Copyright © 2018 Elsevier B.V. All rights reserved.

Mapping carbon flux uncertainty and selecting optimal locations for future flux towers in the Great Plains

USGS Publications Warehouse

Gu, Yingxin; Howard, Daniel M.; Wylie, Bruce K.; Zhang, Li

2012-01-01

Flux tower networks (e. g., AmeriFlux, Agriflux) provide continuous observations of ecosystem exchanges of carbon (e. g., net ecosystem exchange), water vapor (e. g., evapotranspiration), and energy between terrestrial ecosystems and the atmosphere. The long-term time series of flux tower data are essential for studying and understanding terrestrial carbon cycles, ecosystem services, and climate changes. Currently, there are 13 flux towers located within the Great Plains (GP). The towers are sparsely distributed and do not adequately represent the varieties of vegetation cover types, climate conditions, and geophysical and biophysical conditions in the GP. This study assessed how well the available flux towers represent the environmental conditions or "ecological envelopes" across the GP and identified optimal locations for future flux towers in the GP. Regression-based remote sensing and weather-driven net ecosystem production (NEP) models derived from different extrapolation ranges (10 and 50%) were used to identify areas where ecological conditions were poorly represented by the flux tower sites and years previously used for mapping grassland fluxes. The optimal lands suitable for future flux towers within the GP were mapped. Results from this study provide information to optimize the usefulness of future flux towers in the GP and serve as a proxy for the uncertainty of the NEP map.

Does dependency make a difference? The role of convenience, social influence, facilitating condition and self-efficacy on student's purchase behaviour of smartphone

NASA Astrophysics Data System (ADS)

Jaganathan, Mathivannan; Mustapa, Azrain Nasyrah; Hasan, Wan Azlina Wan; Mat, Nik Kamariah Nik; Alekam, Jamal Mohammed Esmail

2014-12-01

It is an undeniable fact that penetration level and usage and sales of Smartphone dramatically increased past few years, whereby; it has increased to almost 60 percent of total population. Despite the high penetration of smartphone, previous studies have exhibited inconsistent findings towards understanding the behavioural intention to use smartphone especially among university students. Thus, the purpose of this study is to examine purchasing behaviour of Smartphone among students. From the literature, five antecedents of purchasing behaviour were identified. Each variable is measured using 7-point Likert scale: convenience (10 items), social influence (6 items), self-efficacy (10 items), facilitating condition (11 items), dependency (14 items) and purchasing behaviour (4 items). Using the primary data collection method, 400 questionnaires were distributed to the target respondents of one of the public higher education in the northern region. The responses collected were 350 completed questionnaires representing 87.5 percent response rate. The data were analysed using Structural Equation Modeling (SEM) using AMOS. Confirmatory factor analysis of measurement models indicates adequate goodness or fit after few items were eliminated through modification indices verifications. Therefore, goodness of fit for the generated structural model shows the adequate fit. This study has established four direct significant causal effects and two significant mediating effects: (1) convenience and dependency, (2) social influence and dependency, (3) facilitating condition and purchase behaviour, (4), dependency and purchase behaviour. The significant mediating results are: (1). Dependency mediates the relationship between convenience and purchase behaviour; (2) dependency mediates social influence and purchase behaviour. Thus, findings suggested that convenience, social influence and dependency play a role in determining students purchase behaviour of smartphone. The researchers hope the findings of this study will contribute theoretically and practically to scholars, marketers and smartphone manufacturers.

Self-Regulated Learning from Illustrated Text: Eye Movement Modelling to Support Use and Regulation of Cognitive Processes during Learning from Multimedia

ERIC Educational Resources Information Center

Scheiter, Katharina; Schubert, Carina; Schüler, Anne

2018-01-01

Background: When learning with text and pictures, learners often fail to adequately process the materials, which can be explained as a failure to self-regulate one's learning by choosing adequate cognitive learning processes. Eye movement modelling examples (EMME) showing how to process multimedia instruction have improved elementary school…

Effects of local vibrations on the dynamics of space truss structures

NASA Technical Reports Server (NTRS)

Warnaar, Dirk B.; Mcgowan, Paul E.

1987-01-01

The paper discusses the influence of local member vibrations on the dynamics of repetitive space truss structures. Several focus problems wherein local member vibration modes are in the frequency range of the global truss modes are discussed. Special attention is given to defining methods that can be used to identify the global modes of a truss structure amidst many local modes. Significant interactions between the motions of local member vibrations and the global behavior are shown to occur in truss structures when: (1) the natural frequencies of the individual members for clamped-clamped boundary conditions are in the vicinity of the global truss frequency; and (2) the total mass of the individual members represents a large portion of the mass of the whole structure. The analysis is carried out with a structural analysis code which uses exact member theory. The modeling detail required using conventional finite element codes to adequately represent such a class of problems is examined. The paper concludes with some practical considerations for the design and dynamic testing of structures which might exhibit such behavior.

An improved simulation of the 2015 El Niño event by optimally correcting the initial conditions and model parameters in an intermediate coupled model

NASA Astrophysics Data System (ADS)

Zhang, Rong-Hua; Tao, Ling-Jiang; Gao, Chuan

2017-09-01

Large uncertainties exist in real-time predictions of the 2015 El Niño event, which have systematic intensity biases that are strongly model-dependent. It is critically important to characterize those model biases so they can be reduced appropriately. In this study, the conditional nonlinear optimal perturbation (CNOP)-based approach was applied to an intermediate coupled model (ICM) equipped with a four-dimensional variational data assimilation technique. The CNOP-based approach was used to quantify prediction errors that can be attributed to initial conditions (ICs) and model parameters (MPs). Two key MPs were considered in the ICM: one represents the intensity of the thermocline effect, and the other represents the relative coupling intensity between the ocean and atmosphere. Two experiments were performed to illustrate the effects of error corrections, one with a standard simulation and another with an optimized simulation in which errors in the ICs and MPs derived from the CNOP-based approach were optimally corrected. The results indicate that simulations of the 2015 El Niño event can be effectively improved by using CNOP-derived error correcting. In particular, the El Niño intensity in late 2015 was adequately captured when simulations were started from early 2015. Quantitatively, the Niño3.4 SST index simulated in Dec. 2015 increased to 2.8 °C in the optimized simulation, compared with only 1.5 °C in the standard simulation. The feasibility and effectiveness of using the CNOP-based technique to improve ENSO simulations are demonstrated in the context of the 2015 El Niño event. The limitations and further applications are also discussed.

lumpR 2.0.0: an R package facilitating landscape discretisation for hillslope-based hydrological models

NASA Astrophysics Data System (ADS)

Pilz, Tobias; Francke, Till; Bronstert, Axel

2017-08-01

The characteristics of a landscape pose essential factors for hydrological processes. Therefore, an adequate representation of the landscape of a catchment in hydrological models is vital. However, many of such models exist differing, amongst others, in spatial concept and discretisation. The latter constitutes an essential pre-processing step, for which many different algorithms along with numerous software implementations exist. In that context, existing solutions are often model specific, commercial, or depend on commercial back-end software, and allow only a limited or no workflow automation at all. Consequently, a new package for the scientific software and scripting environment R, called lumpR, was developed. lumpR employs an algorithm for hillslope-based landscape discretisation directed to large-scale application via a hierarchical multi-scale approach. The package addresses existing limitations as it is free and open source, easily extendible to other hydrological models, and the workflow can be fully automated. Moreover, it is user-friendly as the direct coupling to a GIS allows for immediate visual inspection and manual adjustment. Sufficient control is furthermore retained via parameter specification and the option to include expert knowledge. Conversely, completely automatic operation also allows for extensive analysis of aspects related to landscape discretisation. In a case study, the application of the package is presented. A sensitivity analysis of the most important discretisation parameters demonstrates its efficient workflow automation. Considering multiple streamflow metrics, the employed model proved reasonably robust to the discretisation parameters. However, parameters determining the sizes of subbasins and hillslopes proved to be more important than the others, including the number of representative hillslopes, the number of attributes employed for the lumping algorithm, and the number of sub-discretisations of the representative hillslopes.

New Age of 3D Geological Modelling or Complexity is not an Issue Anymore

NASA Astrophysics Data System (ADS)

Mitrofanov, Aleksandr

2017-04-01

Geological model has a significant value in almost all types of researches related to regional mapping, geodynamics and especially to structural and resource geology of mineral deposits. Well-developed geological model must take into account all vital features of modelling object without over-simplification and also should adequately represent the interpretation of the geologist. In recent years with the gradual exhaustion deposits with relatively simple morphology geologists from all over the world are faced with the necessity of building the representative models for more and more structurally complex objects. Meanwhile, the amount of tools used for that has not significantly changed in the last two-three decades. The most widespread method of wireframe geological modelling now was developed in 1990s and is fully based on engineering design set of instruments (so-called CAD). Strings and polygons representing the section-based interpretation are being used as an intermediate step in the process of wireframes generation. Despite of significant time required for this type of modelling, it still can provide sufficient results for simple and medium-complexity geological objects. However, with the increasing complexity more and more vital features of the deposit are being sacrificed because of fundamental inability (or much greater time required for modelling) of CAD-based explicit techniques to develop the wireframes of the appropriate complexity. At the same time alternative technology which is not based on sectional approach and which uses the fundamentally different mathematical algorithms is being actively developed in the variety of other disciplines: medicine, advanced industrial design, game and cinema industry. In the recent years this implicit technology started to being developed for geological modelling purpose and nowadays it is represented by very powerful set of tools that has been integrated in almost all major commercial software packages. Implicit modelling allows to develop geological models that really correspond with complicated geological reality. Models can include fault blocking, complex structural trends and folding; can be based on excessive input dataset (like lots of drilling on the mining stage) or, on the other hand, on a quite few drillholes intersections with significant input from geological interpretation of the deposit. In any case implicit modelling, if is used correctly, allows to incorporate the whole batch of geological data and relatively quickly get the easily adjustable, flexible and robust geological wireframes that can be used as a reliable foundation on the following stages of geological investigations. In SRK practice nowadays almost all the wireframe models used for structural and resource geology are developed with implicit modelling tools which significantly increased the speed and quality of geological modelling.

Oblique radiation lateral open boundary conditions for a regional climate atmospheric model

NASA Astrophysics Data System (ADS)

Cabos Narvaez, William; De Frutos Redondo, Jose Antonio; Perez Sanz, Juan Ignacio; Sein, Dmitry

2013-04-01

The prescription of lateral boundary conditions in regional atmospheric models represent a very important issue for limited area models. The ill-posed nature of the open boundary conditions makes it necessary to devise schemes in order to filter spurious wave reflections at boundaries, being desirable to have one boundary condition per variable. On the other side, due to the essentially hyperbolic nature of the equations solved in state of the art atmospheric models, external data is required only for inward boundary fluxes. These circumstances make radiation lateral boundary conditions a good choice for the filtering of spurious wave reflections. Here we apply the adaptive oblique radiation modification proposed by Mikoyada and Roseti to each of the prognostic variables of the REMO regional atmospheric model and compare it to the more common normal radiation condition used in REMO. In the proposed scheme, special attention is paid to the estimation of the radiation phase speed, essential to detecting the direction of boundary fluxes. One of the differences with the classical scheme is that in case of outward propagation, the adaptive nudging imposed in the boundaries allows to minimize under and over specifications problems, adequately incorporating the external information.

Hurricane Forecasting with the High-resolution NASA Finite-volume General Circulation Model

NASA Technical Reports Server (NTRS)

Atlas, R.; Reale, O.; Shen, B.-W.; Lin, S.-J.; Chern, J.-D.; Putman, W.; Lee, T.; Yeh, K.-S.; Bosilovich, M.; Radakovich, J.

2004-01-01

A high-resolution finite-volume General Circulation Model (fvGCM), resulting from a development effort of more than ten years, is now being run operationally at the NASA Goddard Space Flight Center and Ames Research Center. The model is based on a finite-volume dynamical core with terrain-following Lagrangian control-volume discretization and performs efficiently on massive parallel architectures. The computational efficiency allows simulations at a resolution of a quarter of a degree, which is double the resolution currently adopted by most global models in operational weather centers. Such fine global resolution brings us closer to overcoming a fundamental barrier in global atmospheric modeling for both weather and climate, because tropical cyclones and even tropical convective clusters can be more realistically represented. In this work, preliminary results of the fvGCM are shown. Fifteen simulations of four Atlantic tropical cyclones in 2002 and 2004 are chosen because of strong and varied difficulties presented to numerical weather forecasting. It is shown that the fvGCM, run at the resolution of a quarter of a degree, can produce very good forecasts of these tropical systems, adequately resolving problems like erratic track, abrupt recurvature, intense extratropical transition, multiple landfall and reintensification, and interaction among vortices.

Emotional intelligence is a second-stratum factor of intelligence: evidence from hierarchical and bifactor models.

PubMed

MacCann, Carolyn; Joseph, Dana L; Newman, Daniel A; Roberts, Richard D

2014-04-01

This article examines the status of emotional intelligence (EI) within the structure of human cognitive abilities. To evaluate whether EI is a 2nd-stratum factor of intelligence, data were fit to a series of structural models involving 3 indicators each for fluid intelligence, crystallized intelligence, quantitative reasoning, visual processing, and broad retrieval ability, as well as 2 indicators each for emotion perception, emotion understanding, and emotion management. Unidimensional, multidimensional, hierarchical, and bifactor solutions were estimated in a sample of 688 college and community college students. Results suggest adequate fit for 2 models: (a) an oblique 8-factor model (with 5 traditional cognitive ability factors and 3 EI factors) and (b) a hierarchical solution (with cognitive g at the highest level and EI representing a 2nd-stratum factor that loads onto g at λ = .80). The acceptable relative fit of the hierarchical model confirms the notion that EI is a group factor of cognitive ability, marking the expression of intelligence in the emotion domain. The discussion proposes a possible expansion of Cattell-Horn-Carroll theory to include EI as a 2nd-stratum factor of similar standing to factors such as fluid intelligence and visual processing.

Estimated effects of temperature on secondary organic aerosol concentrations.

PubMed

Sheehan, P E; Bowman, F M

2001-06-01

The temperature-dependence of secondary organic aerosol (SOA) concentrations is explored using an absorptive-partitioning model under a variety of simplified atmospheric conditions. Experimentally determined partitioning parameters for high yield aromatics are used. Variation of vapor pressures with temperature is assumed to be the main source of temperature effects. Known semivolatile products are used to define a modeling range of vaporization enthalpy of 10-25 kcal/mol-1. The effect of diurnal temperature variations on model predictions for various assumed vaporization enthalpies, precursor emission rates, and primary organic concentrations is explored. Results show that temperature is likely to have a significant influence on SOA partitioning and resulting SOA concentrations. A 10 degrees C decrease in temperature is estimated to increase SOA yields by 20-150%, depending on the assumed vaporization enthalpy. In model simulations, high daytime temperatures tend to reduce SOA concentrations by 16-24%, while cooler nighttime temperatures lead to a 22-34% increase, compared to constant temperature conditions. Results suggest that currently available constant temperature partitioning coefficients do not adequately represent atmospheric SOA partitioning behavior. Air quality models neglecting the temperature dependence of partitioning are expected to underpredict peak SOA concentrations as well as mistime their occurrence.

Design and optimization of selective azaindole amide M1 positive allosteric modulators.

PubMed

Davoren, Jennifer E; O'Neil, Steven V; Anderson, Dennis P; Brodney, Michael A; Chenard, Lois; Dlugolenski, Keith; Edgerton, Jeremy R; Green, Michael; Garnsey, Michelle; Grimwood, Sarah; Harris, Anthony R; Kauffman, Gregory W; LaChapelle, Erik; Lazzaro, John T; Lee, Che-Wah; Lotarski, Susan M; Nason, Deane M; Obach, R Scott; Reinhart, Veronica; Salomon-Ferrer, Romelia; Steyn, Stefanus J; Webb, Damien; Yan, Jiangli; Zhang, Lei

2016-01-15

Selective activation of the M1 receptor via a positive allosteric modulator (PAM) is a new approach for the treatment of the cognitive impairments associated with schizophrenia and Alzheimer's disease. A novel series of azaindole amides and their key pharmacophore elements are described. The nitrogen of the azaindole core is a key design element as it forms an intramolecular hydrogen bond with the amide N-H thus reinforcing the bioactive conformation predicted by published SAR and our homology model. Representative compound 25 is a potent and selective M1 PAM that has well aligned physicochemical properties, adequate brain penetration and pharmacokinetic (PK) properties, and is active in vivo. These favorable properties indicate that this series possesses suitable qualities for further development and studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

A direct method for synthesizing low-order optimal feedback control laws with application to flutter suppression

NASA Technical Reports Server (NTRS)

Mukhopadhyay, V.; Newsom, J. R.; Abel, I.

1980-01-01

A direct method of synthesizing a low-order optimal feedback control law for a high order system is presented. A nonlinear programming algorithm is employed to search for the control law design variables that minimize a performance index defined by a weighted sum of mean square steady state responses and control inputs. The controller is shown to be equivalent to a partial state estimator. The method is applied to the problem of active flutter suppression. Numerical results are presented for a 20th order system representing an aeroelastic wind-tunnel wing model. Low-order controllers (fourth and sixth order) are compared with a full order (20th order) optimal controller and found to provide near optimal performance with adequate stability margins.

Heating requirements and nonadiabatic surface effects for a model in the NTF cryogenic wind tunnel

NASA Technical Reports Server (NTRS)

Macha, J. M.; Landrum, D. B.; Pare, L. A., III; Johnson, C. B.

1988-01-01

A theoretical study has been made of the severity of nonadiabatic surface conditions arising from internal heat sources within a model in a cryogenic wind tunnel. Local surface heating is recognized as having an effect on the development of the boundary layer, which can introduce changes in the flow about the model and affect the wind tunnel data. The geometry was based on the NTF Pathfinder I wind tunnel model. A finite element heat transfer computer code was developed and used to compute the steady state temperature distribution within the body of the model, from which the surface temperature distribution was extracted. Particular three dimensional characteristics of the model were represented with various axisymmetric approximations of the geometry. This analysis identified regions on the surface of the model susceptible to surface heating and the magnitude of the respective surface temperatures. It was found that severe surface heating may occur in particular instances, but could be alleviated with adequate insulating material. The heat flux through the surface of the model was integrated to determine the net heat required to maintain the instrumentation cavity at the prescribed temperature. The influence of the nonadiabatic condition on boundary layer properties and on the validity of the wind tunnel simulation was also investigated.

Challenges in predicting climate change impacts on pome fruit phenology

NASA Astrophysics Data System (ADS)

Darbyshire, Rebecca; Webb, Leanne; Goodwin, Ian; Barlow, E. W. R.

2014-08-01

Climate projection data were applied to two commonly used pome fruit flowering models to investigate potential differences in predicted full bloom timing. The two methods, fixed thermal time and sequential chill-growth, produced different results for seven apple and pear varieties at two Australian locations. The fixed thermal time model predicted incremental advancement of full bloom, while results were mixed from the sequential chill-growth model. To further investigate how the sequential chill-growth model reacts under climate perturbed conditions, four simulations were created to represent a wider range of species physiological requirements. These were applied to five Australian locations covering varied climates. Lengthening of the chill period and contraction of the growth period was common to most results. The relative dominance of the chill or growth component tended to predict whether full bloom advanced, remained similar or was delayed with climate warming. The simplistic structure of the fixed thermal time model and the exclusion of winter chill conditions in this method indicate it is unlikely to be suitable for projection analyses. The sequential chill-growth model includes greater complexity; however, reservations in using this model for impact analyses remain. The results demonstrate that appropriate representation of physiological processes is essential to adequately predict changes to full bloom under climate perturbed conditions with greater model development needed.

Improving a DSM Obtained by Unmanned Aerial Vehicles for Flood Modelling

NASA Astrophysics Data System (ADS)

Mourato, Sandra; Fernandez, Paulo; Pereira, Luísa; Moreira, Madalena

2017-12-01

According to the EU flood risks directive, flood hazard map must be used to assess the flood risk. These maps can be developed with hydraulic modelling tools using a Digital Surface Runoff Model (DSRM). During the last decade, important evolutions of the spatial data processing has been developed which will certainly improve the hydraulic models results. Currently, images acquired with Red/Green/Blue (RGB) camera transported by Unmanned Aerial Vehicles (UAV) are seen as a good alternative data sources to represent the terrain surface with a high level of resolution and precision. The question is if the digital surface model obtain with this data is adequate enough for a good representation of the hydraulics flood characteristics. For this purpose, the hydraulic model HEC-RAS was run with 4 different DSRM for an 8.5 km reach of the Lis River in Portugal. The computational performance of the 4 modelling implementations is evaluated. Two hydrometric stations water level records were used as boundary conditions of the hydraulic model. The records from a third hydrometric station were used to validate the optimal DSRM. The HEC-RAS results had the best performance during the validation step were the ones where the DSRM with integration of the two altimetry data sources.

Prospects of second generation artificial intelligence tools in calibration of chemical sensors.

PubMed

Braibanti, Antonio; Rao, Rupenaguntla Sambasiva; Ramam, Veluri Anantha; Rao, Gollapalli Nageswara; Rao, Vaddadi Venkata Panakala

2005-05-01

Multivariate data driven calibration models with neural networks (NNs) are developed for binary (Cu++ and Ca++) and quaternary (K+, Ca++, NO3- and Cl-) ion-selective electrode (ISE) data. The response profiles of ISEs with concentrations are non-linear and sub-Nernstian. This task represents function approximation of multi-variate, multi-response, correlated, non-linear data with unknown noise structure i.e. multi-component calibration/prediction in chemometric parlance. Radial distribution function (RBF) and Fuzzy-ARTMAP-NN models implemented in the software packages, TRAJAN and Professional II, are employed for the calibration. The optimum NN models reported are based on residuals in concentration space. Being a data driven information technology, NN does not require a model, prior- or posterior- distribution of data or noise structure. Missing information, spikes or newer trends in different concentration ranges can be modeled through novelty detection. Two simulated data sets generated from mathematical functions are modeled as a function of number of data points and network parameters like number of neurons and nearest neighbors. The success of RBF and Fuzzy-ARTMAP-NNs to develop adequate calibration models for experimental data and function approximation models for more complex simulated data sets ensures AI2 (artificial intelligence, 2nd generation) as a promising technology in quantitation.

Physically based approaches incorporating evaporation for early warning predictions of rainfall-induced landslides

NASA Astrophysics Data System (ADS)

Reder, Alfredo; Rianna, Guido; Pagano, Luca

2018-02-01

In the field of rainfall-induced landslides on sloping covers, models for early warning predictions require an adequate trade-off between two aspects: prediction accuracy and timeliness. When a cover's initial hydrological state is a determining factor in triggering landslides, taking evaporative losses into account (or not) could significantly affect both aspects. This study evaluates the performance of three physically based predictive models, converting precipitation and evaporative fluxes into hydrological variables useful in assessing slope safety conditions. Two of the models incorporate evaporation, with one representing evaporation as both a boundary and internal phenomenon, and the other only a boundary phenomenon. The third model totally disregards evaporation. Model performances are assessed by analysing a well-documented case study involving a 2 m thick sloping volcanic cover. The large amount of monitoring data collected for the soil involved in the case study, reconstituted in a suitably equipped lysimeter, makes it possible to propose procedures for calibrating and validating the parameters of the models. All predictions indicate a hydrological singularity at the landslide time (alarm). A comparison of the models' predictions also indicates that the greater the complexity and completeness of the model, the lower the number of predicted hydrological singularities when no landslides occur (false alarms).

Model documentation: Renewable Fuels Module of the National Energy Modeling System

NASA Astrophysics Data System (ADS)

1994-04-01

This report documents the objectives, analytical approach, and design of the National Energy Modeling System (NEMS) Renewable Fuels Module (RFM) as it related to the production of the 1994 Annual Energy Outlook (AEO94) forecasts. The report catalogues and describes modeling assumptions, computational methodologies, data inputs, and parameter estimation techniques. A number of offline analyses used in lieu of RFM modeling components are also described. This documentation report serves two purposes. First, it is a reference document for model analysts, model users, and the public interested in the construction and application of the RFM. Second, it meets the legal requirement of the Energy Information Administration (EIA) to provide adequate documentation in support of its models. The RFM consists of six analytical submodules that represent each of the major renewable energy resources -- wood, municipal solid waste (MSW), solar energy, wind energy, geothermal energy, and alcohol fuels. Of these six, four are documented in the following chapters: municipal solid waste, wind, solar and biofuels. Geothermal and wood are not currently working components of NEMS. The purpose of the RFM is to define the technological and cost characteristics of renewable energy technologies, and to pass these characteristics to other NEMS modules for the determination of mid-term forecasted renewable energy demand.

Hypochondriasis and health anxiety: conceptual challenges.

PubMed

Starcevic, Vladan

2013-01-01

The relationship between hypochondriasis and health anxiety is examined by considering a DSM-5 proposal to replace the current heterogeneous concept of hypochondriasis with two disorders. The key issues are to ascertain whether these conditions are relatively distinct and whether they adequately represent the full range of clinical manifestations encompassed by hypochondriasis.

Do Parties' Ideological Positions Matter? The Effects of Alienation and Indifference on Individuals' Turnout Decisions

ERIC Educational Resources Information Center

Melton, James Douglas

2009-01-01

Both spatial theories of voting and our intuitions lead us to expect that political parties' ideological positions should affect individuals' turnout decisions. Contrary to these expectations, existing research finds that neither feelings of alienation--that no party adequately represents an individual's ideological position--nor…

A GUIDE FOR USE IN DEVELOPING TRAINING PROGRAMS IN DRAFTING AND DESIGN TECHNOLOGY.

ERIC Educational Resources Information Center

Mississippi State Dept. of Education, Jackson.

INITIAL COURSE OUTLINES WERE PREPARED BY INSTRUCTORS. INDIVIDUAL COURSES WERE THEN EXPANDED AND COORDINATED WITH OTHER COURSES. THE CURRICULUM LABORATORY STAFF REORGANIZED AND EDITED THE MATERIAL. A COMMITTEE OF INDUSTRIAL REPRESENTATIVES REVIEWED AND PERSONALLY ENDORSED IT AS BEING APPROPRIATE AND ADEQUATE FOR TRAINING DRAFTING AND DESIGN…

7 CFR 1000.27 - Handler responsibility for records and facilities.

Code of Federal Regulations, 2010 CFR

2010-01-01

... make such records and its facilities available to the market administrator. If adequate records of a... and made available, any skim milk and butterfat required to be reported by such handler for which... quantities of skim milk and butterfat contained in, or represented by, products received in any form...

Rhetoric and Truth: A Note on Aristotle, Rhetoric 1355a 21-24

ERIC Educational Resources Information Center

Grimaldi, William M. A.

1978-01-01

A passage from Aristotle is discussed and interpreted. Rhetoric represents truth and justice in any situation for the auditor through the use of language. The usefulness of rhetoric lies in its ability to assure an adequate and competent articulation of truth and justice. (JF)

78 FR 6770 - Notice of Intent To Establish an Adequate Yearly Progress Negotiated Rulemaking Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-31

... representatives of Indian tribes for the Committee from among individuals nominated by tribes whose students... the following methods: Send comments or nominations to Ms. Sue Bement, Designated Federal Officer... content standards, assessments, and a specific methodology for calculating the AYP of students (together...

Ecological subregions of the interior Columbia basin, USA.

Treesearch

P.F. Hessburg; R.B. Salter; R.B. Richmond; B.G. Smith

2000-01-01

Land evaluations are not always conducted with adequate understanding of the relevant geologic and climatic contexts and their appropriate scales. This understanding is essential for developing representative sampling, monitoring, and conservation designs, and for pooling results of landscape analysis. To provide context for several regions of the interior northwestern...

Designing Writing Programs in Business and Industry.

ERIC Educational Resources Information Center

Freed, Richard C.

Current training in writing for business and industry usually takes the form of short courses. However, the short course is an inappropriate way to teach writing because it is inefficient, represents writing behaviors or strategies inappropriate for some writers, rarely allows time for adequate criticism and revision, presents too much material in…

Emotional and Behavioral Problems Reported in Child Welfare over 3 Years

ERIC Educational Resources Information Center

McCrae, Julie S.

2009-01-01

Child welfare agencies are required to provide services that ensure that children receive adequate mental health care. This study provides a comprehensive view of the emotional and behavioral problems of children who are referred to child welfare services, using nationally representative data. Bivariate analyses compare rates by child…

44 CFR 12.6 - Establishment of advisory committees.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the advisory committee to be fairly balanced in terms of the points of view represented in the... employed by it), will be provided adequate quarters, and will have funds available to meet its other... should describe the Agency's plan to attain balanced membership on the proposed committee, as prescribed...

Through Family Eyes: Towards a More Adequate Perspective for Viewing Native American Religious Life.

ERIC Educational Resources Information Center

Swanson, Tod D.

1997-01-01

Examines strategies used by non-Native scholars who write or teach about American-Indian religious traditions. The current trend--an apologetic stance emphasizing contrasting "representative" Native and European voices--unwittingly reinforces stereotypes and appropriation of idealized Native images. In contrast, approaching the subject…

How Well Do the NSF Funded Elementary Mathematics Curricula Align with the GAISE Report Recommendations?

ERIC Educational Resources Information Center

Bargagliotti, Anna E.

2012-01-01

Statistics and probability have become an integral part of mathematics education. Therefore it is important to understand whether curricular materials adequately represent statistical ideas. The "Guidelines for Assessment and Instruction in Statistics Education" (GAISE) report (Franklin, Kader, Mewborn, Moreno, Peck, Perry, & Scheaffer, 2007),…

21 CFR 809.10 - Labeling for in vitro diagnostic products.

Code of Federal Regulations, 2012 CFR

2012-04-01

... procedure, e.g., qualitative or quantitative. (3) Summary and explanation of the test. Include a short... provides other than quantitative results, provide an adequate description of expected results. (10... are met: (i) For a product in the laboratory research phase of development, and not represented as an...

21 CFR 809.10 - Labeling for in vitro diagnostic products.

Code of Federal Regulations, 2011 CFR

2011-04-01

... procedure, e.g., qualitative or quantitative. (3) Summary and explanation of the test. Include a short... provides other than quantitative results, provide an adequate description of expected results. (10... are met: (i) For a product in the laboratory research phase of development, and not represented as an...

21 CFR 809.10 - Labeling for in vitro diagnostic products.

Code of Federal Regulations, 2013 CFR

2013-04-01

... procedure, e.g., qualitative or quantitative. (3) Summary and explanation of the test. Include a short... provides other than quantitative results, provide an adequate description of expected results. (10... are met: (i) For a product in the laboratory research phase of development, and not represented as an...

21 CFR 809.10 - Labeling for in vitro diagnostic products.

Code of Federal Regulations, 2014 CFR

2014-04-01

... procedure, e.g., qualitative or quantitative. (3) Summary and explanation of the test. Include a short... provides other than quantitative results, provide an adequate description of expected results. (10... are met: (i) For a product in the laboratory research phase of development, and not represented as an...

Using High Resolution Simulations with WRF/SSiB Regional Climate Model Constrained by In Situ Observations to Assess the Impacts of Dust in Snow in the Upper Colorado River Basin

NASA Astrophysics Data System (ADS)

Oaida, C. M.; Skiles, M.; Painter, T. H.; Xue, Y.

2015-12-01

The mountain snowpack is an essential resource for both the environment as well as society. Observational and energy balance modeling work have shown that dust on snow (DOS) in western U.S. (WUS) is a major contributor to snow processes, including snowmelt timing and runoff amount in regions like the Upper Colorado River Basin (UCRB). In order to accurately estimate the impact of DOS to the hydrologic cycle and water resources, now and under a changing climate, we need to be able to (1) adequately simulate the snowpack (accumulation), and (2) realistically represent DOS processes in models. Energy balance models do not capture the impact on a broader local or regional scale, nor the land-atmosphere feedbacks, while GCM studies cannot resolve orographic-related precipitation processes, and therefore snowpack accumulation, owing to coarse spatial resolution and smoother terrain. All this implies the impacts of dust on snow on the mountain snowpack and other hydrologic processes are likely not well captured in current modeling studies. Recent increase in computing power allows for RCMs to be used at higher spatial resolutions, while recent in situ observations of dust in snow properties can help constrain modeling simulations. Therefore, in the work presented here, we take advantage of these latest resources to address the some of the challenges outlined above. We employ the newly enhanced WRF/SSiB regional climate model at 4 km horizontal resolution. This scale has been shown by others to be adequate in capturing orographic processes over WUS. We also constrain the magnitude of dust deposition provided by a global chemistry and transport model, with in situ measurements taken at sites in the UCRB. Furthermore, we adjust the dust absorptive properties based on observed values at these sites, as opposed to generic global ones. This study aims to improve simulation of the impact of dust in snow on the hydrologic cycle and related water resources.

Capillary Flow of Liquid Metals in Brazing

NASA Astrophysics Data System (ADS)

Dehsara, Mohammad

Capillary flow is driven or controlled by capillary forces, exerted at the triple line where the fluid phases meet the solid boundary. Phase field (PF) models naturally accommodate diffusive triple line motion with variable contact angle, thus allowing for the no-slip boundary condition without the stress singularities. Moreover, they are uniquely suited for modeling of topological discontinuities which often arise during capillary flows. In this study, we consider diffusive triple line motion within two PF models: the compositionally compressible (CC) and the incompressible (IC) models. We derive the IC model as a systematic approximation to the CC model, based on a suitable choice of continuum velocity field. The CC model, applied to the fluids of dissimilar mass densities, exhibits a computational instability at the triple line. The IC model perfectly represents the analytic equilibria. We develop the parameter identification procedure and show that the triple line kinetics can be well represented by the IC model's diffusive boundary condition. The IC model is first tested by benchmarking the phase-field and experimental kinetics of water, and silicone oil spreading over the glass plates in which two systems do not interact with the substrate. Then, two high-temperature physical settings involving spreading of the molten Al-Si alloy: one over a rough wetting substrate, the other over a non-wetting substrate are modeled in a T-joint structure which is a typical geometric configuration for many brazing and soldering applications. Surface roughness directly influences the spreading of the molten metal by causing break-ups of the liquid film and trapping the liquid away from the joint. In the early stages of capillary flow over non-wetting surface, the melting and flow are concurrent, so that the kinetics of wetting is strongly affected by the variations in effective viscosity of the partially molten metal. We define adequate time-dependent functions for the variations of Al-Si alloy viscosity and triple line mobility to describe the wetting kinetics.

A Knowledge-Based Representation Scheme for Environmental Science Models

NASA Technical Reports Server (NTRS)

Keller, Richard M.; Dungan, Jennifer L.; Lum, Henry, Jr. (Technical Monitor)

1994-01-01

One of the primary methods available for studying environmental phenomena is the construction and analysis of computational models. We have been studying how artificial intelligence techniques can be applied to assist in the development and use of environmental science models within the context of NASA-sponsored activities. We have identified several high-utility areas as potential targets for research and development: model development; data visualization, analysis, and interpretation; model publishing and reuse, training and education; and framing, posing, and answering questions. Central to progress on any of the above areas is a representation for environmental models that contains a great deal more information than is present in a traditional software implementation. In particular, a traditional software implementation is devoid of any semantic information that connects the code with the environmental context that forms the background for the modeling activity. Before we can build AI systems to assist in model development and usage, we must develop a representation for environmental models that adequately describes a model's semantics and explicitly represents the relationship between the code and the modeling task at hand. We have developed one such representation in conjunction with our work on the SIGMA (Scientists' Intelligent Graphical Modeling Assistant) environment. The key feature of the representation is that it provides a semantic grounding for the symbols in a set of modeling equations by linking those symbols to an explicit representation of the underlying environmental scenario.

Mechanics-based statistics of failure risk of quasibrittle structures and size effect on safety factors.

PubMed

Bazant, Zdenĕk P; Pang, Sze-Dai

2006-06-20

In mechanical design as well as protection from various natural hazards, one must ensure an extremely low failure probability such as 10(-6). How to achieve that goal is adequately understood only for the limiting cases of brittle or ductile structures. Here we present a theory to do that for the transitional class of quasibrittle structures, having brittle constituents and characterized by nonnegligible size of material inhomogeneities. We show that the probability distribution of strength of the representative volume element of material is governed by the Maxwell-Boltzmann distribution of atomic energies and the stress dependence of activation energy barriers; that it is statistically modeled by a hierarchy of series and parallel couplings; and that it consists of a broad Gaussian core having a grafted far-left power-law tail with zero threshold and amplitude depending on temperature and load duration. With increasing structure size, the Gaussian core shrinks and Weibull tail expands according to the weakest-link model for a finite chain of representative volume elements. The model captures experimentally observed deviations of the strength distribution from Weibull distribution and of the mean strength scaling law from a power law. These deviations can be exploited for verification and calibration. The proposed theory will increase the safety of concrete structures, composite parts of aircraft or ships, microelectronic components, microelectromechanical systems, prosthetic devices, etc. It also will improve protection against hazards such as landslides, avalanches, ice breaks, and rock or soil failures.

A medical prescription for a mind

NASA Astrophysics Data System (ADS)

Simões da Fonseca, J.

1999-03-01

The author who is an expert in clinical psychiatry deals with the problem of modeling human Mind the way physicians implicitly use when their profession renders necessary to intervene to help or even cure patients. If physicists, mathematicians or cognitive science specialists and engineers may propose artificial designs for a mind, psychiatrists and psychologists have developed reliable diagnostic systems for the classification of normal or else psychopathological states. Usually in Psychiatry it is not made any use of an algorithmic approach to describe and characterize psychological processes during cognitive, perceptual, emotional, motivational processes or else anticipatory processes, distinct types of memory, learning processes, etc. Differently from what is mentioned in Neuropsychological literature the author and his group were able to find a significant and consistent relationship between the level of ostensive expression of symptoms and competence in interpretation of information carried by verbal communication during the simulation of social interactions by restrict groups of experimenters. Furthermore it is shown how dendro-dendritic models of neural processing are adequate to represent symbolic processes performed by local operators in the Cortex, as well as the usefulness of models of chemical reactors either batch reactors or else flow plug reactors to represent virtual neural networks capable of clarifying some aspects of cognition and of the structure of the Self. Finally many episodes of the life of the late Warren Sturgis McCulloch are recalled as attribute of gratitude of the author who was his before the last student.

Sequencing the transcriptome of milk production: milk trumps mammary tissue.

PubMed

Lemay, Danielle G; Hovey, Russell C; Hartono, Stella R; Hinde, Katie; Smilowitz, Jennifer T; Ventimiglia, Frank; Schmidt, Kimberli A; Lee, Joyce W S; Islas-Trejo, Alma; Silva, Pedro Ivo; Korf, Ian; Medrano, Juan F; Barry, Peter A; German, J Bruce

2013-12-12

Studies of normal human mammary gland development and function have mostly relied on cell culture, limited surgical specimens, and rodent models. Although RNA extracted from human milk has been used to assay the mammary transcriptome non-invasively, this assay has not been adequately validated in primates. Thus, the objectives of the current study were to assess the suitability of lactating rhesus macaques as a model for lactating humans and to determine whether RNA extracted from milk fractions is representative of RNA extracted from mammary tissue for the purpose of studying the transcriptome of milk-producing cells. We confirmed that macaque milk contains cytoplasmic crescents and that ample high-quality RNA can be obtained for sequencing. Using RNA sequencing, RNA extracted from macaque milk fat and milk cell fractions more accurately represented RNA from mammary epithelial cells (cells that produce milk) than did RNA from whole mammary tissue. Mammary epithelium-specific transcripts were more abundant in macaque milk fat, whereas adipose or stroma-specific transcripts were more abundant in mammary tissue. Functional analyses confirmed the validity of milk as a source of RNA from milk-producing mammary epithelial cells. RNA extracted from the milk fat during lactation accurately portrayed the RNA profile of milk-producing mammary epithelial cells in a non-human primate. However, this sample type clearly requires protocols that minimize RNA degradation. Overall, we validated the use of RNA extracted from human and macaque milk and provided evidence to support the use of lactating macaques as a model for human lactation.

Effectiveness of the Treatment Readiness and Induction Program for Increasing Adolescent Motivation for Change

PubMed Central

Becan, Jennifer E.; Knight, Danica K.; Crawley, Rachel D.; Joe, George W.; Flynn, Patrick M.

2014-01-01

Success in substance abuse treatment is improved by problem recognition, desire to seek help, and readiness to engage in treatment, all of which are important aspects of motivation. Interventions that facilitate these at treatment induction for adolescents are especially needed. The purpose of this study is to assess the effectiveness of TRIP (Treatment Readiness and Induction Program) in promoting treatment motivation. Data represent 519 adolescents from 6 residential programs who completed assessments at treatment intake (Time 1) and 35 days after admission (Time 2). The design consisted of a comparison sample (n = 281) that had enrolled in treatment prior to implementation of TRIP (standard operating practice) and a sample of clients that had entered treatment after TRIP began and received standard operating practice enhanced by TRIP (n = 238). Repeated measures ANCOVAs were conducted using each Time 2 motivation scale as a dependent measure. Motivation scales were conceptualized as representing sequential stages of change. LISREL was used to test a structural model involving TRIP participation, gender, drug use severity, juvenile justice involvement, age, race-ethnicity, prior treatment, and urgency as predictors of the stages of treatment motivation. Compared to standard practice, adolescents receiving TRIP demonstrated greater gains in problem recognition, even after controlling for the other variables in the model. The model fit was adequate, with TRIP directly affecting problem recognition and indirectly affecting later stages of change (desire for help and treatment readiness). Future studies should examine which specific components of TRIP affect change in motivation. PMID:25456094

Modelling of robotic work cells using agent based-approach

NASA Astrophysics Data System (ADS)

Sękala, A.; Banaś, W.; Gwiazda, A.; Monica, Z.; Kost, G.; Hryniewicz, P.

2016-08-01

In the case of modern manufacturing systems the requirements, both according the scope and according characteristics of technical procedures are dynamically changing. This results in production system organization inability to keep up with changes in a market demand. Accordingly, there is a need for new design methods, characterized, on the one hand with a high efficiency and on the other with the adequate level of the generated organizational solutions. One of the tools that could be used for this purpose is the concept of agent systems. These systems are the tools of artificial intelligence. They allow assigning to agents the proper domains of procedures and knowledge so that they represent in a self-organizing system of an agent environment, components of a real system. The agent-based system for modelling robotic work cell should be designed taking into consideration many limitations considered with the characteristic of this production unit. It is possible to distinguish some grouped of structural components that constitute such a system. This confirms the structural complexity of a work cell as a specific production system. So it is necessary to develop agents depicting various aspects of the work cell structure. The main groups of agents that are used to model a robotic work cell should at least include next pattern representatives: machine tool agents, auxiliary equipment agents, robots agents, transport equipment agents, organizational agents as well as data and knowledge bases agents. In this way it is possible to create the holarchy of the agent-based system.

Building functional groups of marine benthic macroinvertebrates on the basis of general community assembly mechanisms

NASA Astrophysics Data System (ADS)

Alexandridis, Nikolaos; Bacher, Cédric; Desroy, Nicolas; Jean, Fred

2017-03-01

The accurate reproduction of the spatial and temporal dynamics of marine benthic biodiversity requires the development of mechanistic models, based on the processes that shape macroinvertebrate communities. The modelled entities should, accordingly, be able to adequately represent the many functional roles that are performed by benthic organisms. With this goal in mind, we applied the emergent group hypothesis (EGH), which assumes functional equivalence within and functional divergence between groups of species. The first step of the grouping involved the selection of 14 biological traits that describe the role of benthic macroinvertebrates in 7 important community assembly mechanisms. A matrix of trait values for the 240 species that occurred in the Rance estuary (Brittany, France) in 1995 formed the basis for a hierarchical classification that generated 20 functional groups, each with its own trait values. The functional groups were first evaluated based on their ability to represent observed patterns of biodiversity. The two main assumptions of the EGH were then tested, by assessing the preservation of niche attributes among the groups and the neutrality of functional differences within them. The generally positive results give us confidence in the ability of the grouping to recreate functional diversity in the Rance estuary. A first look at the emergent groups provides insights into the potential role of community assembly mechanisms in shaping biodiversity patterns. Our next steps include the derivation of general rules of interaction and their incorporation, along with the functional groups, into mechanistic models of benthic biodiversity.

Assessing the groundwater fortunes of aquifers in the White Volta Basin, Ghana: An application of numerical groundwater flow modeling and isotopic studies

NASA Astrophysics Data System (ADS)

Oteng, F. M.; Yidana, S. M.; Alo, C. A.

2012-12-01

Effective development and informed management of groundwater resources represent a critical opportunity for improved rural water supply in Ghana and enhanced livelihoods particularly in the northern part of the White Volta Basin, a region already prone to a myriad of water-related infirmities. If adequately developed, the resource will form a sufficient buffer against the effects of climate change/variability and foster food security and sustainable livelihoods among the largely peasant communities in the region. This research presents the results of a preliminary assessment of the hydrogeological conditions and recharge regimes of the aquifers in the Northern parts of the White Volta Basin, Ghana. Results of estimates of groundwater recharge through the conventional isotopic and mass balance techniques are presented. Details of the groundwater flow pattern and preliminary delineation of local and regional groundwater recharge areas are presented from initial simulations of the hydrogeological system with a robust groundwater flow simulation code, MODFLOW, in the Groundwater Modeling System, GMS, version 7.1. The stream flow and evapotranspiration components of the program were activated to incorporate surface flow processes, so that the resulting model represents the conditions of the entire hydrological system. The results of this study form a platform for detailed numerical assessment of the conditions of the aquifers in the area under transient conditions of fluctuating rainfall patterns in the face of climate change/variability.

Review of simulation techniques for Aquifer Thermal Energy Storage (ATES)

NASA Astrophysics Data System (ADS)

Mercer, J. W.; Faust, C. R.; Miller, W. J.; Pearson, F. J., Jr.

1981-03-01

The analysis of aquifer thermal energy storage (ATES) systems rely on the results from mathematical and geochemical models. Therefore, the state-of-the-art models relevant to ATES were reviewed and evaluated. These models describe important processes active in ATES including ground-water flow, heat transport (heat flow), solute transport (movement of contaminants), and geochemical reactions. In general, available models of the saturated ground-water environment are adequate to address most concerns associated with ATES; that is, design, operation, and environmental assessment. In those cases where models are not adequate, development should be preceded by efforts to identify significant physical phenomena and relate model parameters to measurable quantities.

Prediction of cavity growth by solution of salt around boreholes. (Report No. IITRI-C--6313-14)

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

Snow, R.H. Chang, D.S.

1975-06-30

A mathematical model is developed to simulate the process of salt dissolution in a salt formation. The calibration of this model using Detroit Mine data is done systematically by the method of nonlinear regression. The brine concentrations calculated from the regression fit the measured data from Detroit Mine experiment within 10 percent. Because the Detroit data includes periods when the inlet flow is shut off, the agreement with Detroit data indicates that the model adequately represents natural convection effects to predict the cavity growth at very slow feed rates. The prediction has been done to calculate the cavity growth atmore » feed rate of one gal/h and one gal/day over a period of 10,000 y. Result shows that the cavity growth is a wide-flaring type and that the significant growth of the cavity only occurs at top layer. The prediction involves a very great extrapolation of time from the Detroit data, but it will be valid if the mechanism of solution does not change.« less

Internal ocean-atmosphere variability drives megadroughts in Western North America.

PubMed

Coats, S; Smerdon, J E; Cook, B I; Seager, R; Cook, E R; Anchukaitis, K J

2016-09-28

Multidecadal droughts that occurred during the Medieval Climate Anomaly represent an important target for validating the ability of climate models to adequately characterize drought risk over the near-term future. A prominent hypothesis is that these megadroughts were driven by a centuries-long radiatively forced shift in the mean state of the tropical Pacific Ocean. Here we use a novel combination of spatiotemporal tree-ring reconstructions of Northern Hemisphere hydroclimate to infer the atmosphere-ocean dynamics that coincide with megadroughts over the American West, and find that these features are consistently associated with ten-to-thirty year periods of frequent cold El Niño Southern Oscillation conditions and not a centuries-long shift in the mean of the tropical Pacific Ocean. These results suggest an important role for internal variability in driving past megadroughts. State-of-the art climate models from the Coupled Model Intercomparison Project phase 5, however, do not simulate a consistent association between megadroughts and internal variability of the tropical Pacific Ocean, with implications for our confidence in megadrought risk projections.

On the Development of a New Nonequilibrium Chemistry Model for Mars Entry

NASA Technical Reports Server (NTRS)

Jaffe, R. L.; Schwenke, D. W.; Chaban, G. M.; Prabhu, D. K.; Johnston, C. O.; Panesi, M.

2017-01-01

This paper represents a summary of results to date of an on-going effort at NASA Ames Research Center to develop a physics-based non-equilibrium model for hypersonic entry into the Martian atmosphere. Our approach is to first compute potential energy surfaces based on accurate solutions of the electronic Schroedinger equation and then use quasiclassical trajectory calculations to obtain reaction cross sections and rate coefficients based on these potentials. We have presented new rate coefficients for N2 dissociation and CO dissociation and exchange reactions. These results illustrate shortcomings with some of the rate coefficients in Parks original T-Tv model for Mars entries and with some of the 30-45 year old shock tube data. We observe that the shock tube experiments of CO + O dissociation did not adequately account for the exchange reaction that leads to formation of C + O2. This reaction is actually the primary channel for CO removal in the shock layer at temperatures below 10,000 K, because the reaction enthalpy for exchange is considerably lower than the comparable value for dissociation.

The Effect of Widowhood on Mental Health - an Analysis of Anticipation Patterns Surrounding the Death of a Spouse.

PubMed

Siflinger, Bettina

2017-12-01

This study explores the effects of widowhood on mental health by taking into account the anticipation and adaptation to the partner's death. The empirical analysis uses representative panel data from the USA that are linked to administrative death records of the National Death Index. I estimate static and dynamic specifications of the panel probit model in which unobserved heterogeneity is modeled with correlated random effects. I find strong anticipation effects of the partner's death on the probability of depression, implying that the partner's death event cannot be assumed to be exogenous in econometric models. In the absence of any anticipation effects, the partner's death has long-lasting mental health consequences, leading to a significantly slower adaptation to widowhood. The results suggest that both anticipation effects and adaptation effects can be attributed to a caregiver burden and to the cause of death. The findings of this study have important implications for designing adequate social policies for the elderly US population that alleviate the negative consequences of bereavement. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Design of Raft Foundations for High-Rise Buildings on Jointed Rock

NASA Astrophysics Data System (ADS)

Justo, J. L.; García-Núñez, J.-C.; Vázquez-Boza, M.; Justo, E.; Durand, P.; Azañón, J. M.

2014-07-01

This paper presents calculations of displacements and bending moments in a 2-m-thick reinforced-concrete foundation slab using three-dimensional finite-element software. A preliminary paper was presented by Justo et al. (Rock Mech Rock Eng 43:287-304, 2010). The slab is the base of a tower of 137 m height above foundation, supported on jointed and partly weathered basalt and scoria. Installation of rod extensometers at different depths below foundation allowed comparison between measured displacements and displacements calculated using moduli obtained from rock classification systems and three material models: elastic, Mohr-Coulomb and hardening (H). Although all three material models can provide acceptable results, the H model is preferable when there are unloading processes. Acceptable values of settlement may be achieved with medium meshing and an approximate distribution of loads. The absolute values of negative bending moments (tensions below) increase as the rock mass modulus decreases or when the mesh is refined. The paper stresses the importance of adequately representing the details of the distribution of loads and the necessity for fine meshing to obtain acceptable values of bending moments.

Simulation of the ground-water flow system and proposed withdrawals in the northern part of Vekol Valley, Arizona

USGS Publications Warehouse

Hollett, K.J.; Marie, J.R.

1987-01-01

Pursuant to the Ak-Chin Indian Community Water Rights Settlement Act (Public Law 95-328-enacted on July 28, 1978) a study was undertaken to assess the effect of proposed groundwater withdrawal from Federal lands near the reservation. The first area to be evaluated was the northern part of the Vekol Valley. The evaluation was made using a numerical model based on detailed geohydrologic concepts developed during the study. The numerical model, which was calibrated to steady-state and transient groundwater conditions in the northern part of Vekol Valley, adequately duplicated the conceptual model and was used to estimate the effect of withdrawing approximately 174,000 acre-ft from the system during a 25-yr period. At the end of the 25-yr period, the water level was drawn down an average of about 95 ft, and about 150,5000 acre-ft of water was removed from storage. The 150,500 acre-ft of water represents 43% of the estimated recoverable groundwater in storage. (Author 's abstract)

Enhancement of docosahexaenoic acid production by Schizochytrium SW1 using response surface methodology

NASA Astrophysics Data System (ADS)

Nazir, Mohd Yusuf Mohd; Al-Shorgani, Najeeb Kaid Nasser; Kalil, Mohd Sahaid; Hamid, Aidil Abdul

2015-09-01

In this study, three factors (fructose concentration, agitation speed and monosodium glutamate (MSG) concentration) were optimized to enhance DHA production by Schizochytrium SW1 using response surface methodology (RSM). Central composite design was applied as the experimental design and analysis of variance (ANOVA) was used to analyze the data. The experiments were conducted using 500 mL flask with 100 mL working volume at 30°C for 96 hours. ANOVA analysis revealed that the process was adequately represented significantly by the quadratic model (p<0.0001) and two of the factors namely agitation speed and MSG concentration significantly affect DHA production (p<0.005). Level of influence for each variable and quadratic polynomial equation were obtained for DHA production by multiple regression analyses. The estimated optimum conditions for maximizing DHA production by SW1 were 70 g/L fructose, 250 rpm agitation speed and 12 g/L MSG. Consequently, the quadratic model was validated by applying of the estimated optimum conditions, which confirmed the model validity and 52.86% of DHA was produced.

Evaluation of Contamination Inspection and Analysis Methods through Modeling System Performance

NASA Technical Reports Server (NTRS)

Seasly, Elaine; Dever, Jason; Stuban, Steven M. F.

2016-01-01

Contamination is usually identified as a risk on the risk register for sensitive space systems hardware. Despite detailed, time-consuming, and costly contamination control efforts during assembly, integration, and test of space systems, contaminants are still found during visual inspections of hardware. Improved methods are needed to gather information during systems integration to catch potential contamination issues earlier and manage contamination risks better. This research explores evaluation of contamination inspection and analysis methods to determine optical system sensitivity to minimum detectable molecular contamination levels based on IEST-STD-CC1246E non-volatile residue (NVR) cleanliness levels. Potential future degradation of the system is modeled given chosen modules representative of optical elements in an optical system, minimum detectable molecular contamination levels for a chosen inspection and analysis method, and determining the effect of contamination on the system. By modeling system performance based on when molecular contamination is detected during systems integration and at what cleanliness level, the decision maker can perform trades amongst different inspection and analysis methods and determine if a planned method is adequate to meet system requirements and manage contamination risk.

Latent trait cortisol (LTC) during pregnancy: Composition, continuity, change, and concomitants.

PubMed

Giesbrecht, Gerald F; Bryce, Crystal I; Letourneau, Nicole; Granger, Douglas A

2015-12-01

Individual differences in the activity of the hypothalamic pituitary adrenal (HPA) axis are often operationalized using summary measures of cortisol that are taken to represent stable individual differences. Here we extend our understanding of a novel latent variable approach to latent trait cortisol (LTC) as a measure of trait-like HPA axis function during pregnancy. Pregnant women (n=380) prospectively collected 8 diurnal saliva samples (4 samples/day, 2 days) within each trimester. Saliva was assayed for cortisol. Confirmatory factor analyses were used to fit LTC models to early morning and daytime cortisol. For individual trimester data, only the daytime LTC models had adequate fit. These daytime LTC models were strongly correlated between trimesters and stable over pregnancy. Daytime LTC was unrelated to the cortisol awakening response and the daytime slope but strongly correlated with the area under the curve from ground. The findings support the validity of LTC as a measure of cortisol during pregnancy and suggest that it is not affected by pregnancy-related changes in HPA axis function. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cancer in Inflammatory Bowel Disease: lessons from animal models

PubMed Central

Sussman, Daniel; Santaolalla, Rebeca; Strobel, Sebastian; Dheer, Rishu; Abreu, Maria T.

2012-01-01

Purpose of the review Human colitis-associated cancers (CAC) represent a heterogeneous group of conditions in which multiple oncogenic pathways are involved. In this manuscript we reviewed the latest studies using genetic, chemically induced, bacterial and innate immunity induced experimental models of colitis-associated cancer. Recent findings Using the azoxymethane-dextran sodium sulfate model wound healing pathways seems to be required in the development of CAC. There is also an emerging understanding that commensal and/or pathogenic bacteria can promote tumorigenesis, through T cell mediated inflammation. Using specific transgenic mice (villin-CD98, T cell SMAD7, villin-TLR4) or specific knock-out mice, investigators have identified that derangements in epithelial or innate and adaptive immune pathways can result in CAC. Subtle perturbations in epithelial repair—both too little or too exuberant, can render mice susceptible to tumorigenesis. Summary With the aid of animal models, we have witnessed a rapid expansion of our knowledge of the molecular and immunologic mechanisms underlying inflammatory cancers. Though animal models have contributed a discrete amount of information to our understanding of tumorigenesis in the setting of intestinal inflammation it is clear that no single animal model will be able to adequately recapitulate the pathogenesis of complex CRCs, but each model gets us one step closer to comprehending the nature of CAC. PMID:22614440

Micro-Mechanical Modeling of Ductile Fracture in Welded Aluminum-Lithium Alloys

NASA Technical Reports Server (NTRS)

Ibrahim, Ahmed

2002-01-01

This computation model for microscopic crack growth in welded aluminum-lithium alloys consists of a cavity with initial volume specified by the fraction f(sub 0), i.e. the void volume relative to the cell volume. Thus, cell size D and initial porosity f(sub 0) defines the key parameters in this model. The choice of cell size requires: 1) D must be representative of the large inclusion spacing. 2) Predicted R-curves scale almost proportionally with D for fixed f(sub 0). 3) mapping of one finite element per cell must provide adequate resolution of the stress-strain fields in the active layer and the adjacent material. For the ferritic steels studied thus far with this model, calibrated cell sizes range from 50-200 microns with f(sub 0) in the 0.0001 to 0.004 micron range. This range of values for D and f (sub 0) satisfies issues 1) and 3). This computational model employs the Gurson and Tvergaard constitutive model for porous plastic materials to describe the progressive damage of cells due to the growth of pre-existing voids. The model derives from a rigid-plastic limit analysis of a solid having a volume fraction (f) of voids approximated by a homogenous spherical body containing a spherical void.

Derivation of optical constants for nanophase hematite and application to modeled abundances from in-situ Martian reflectance spectra

NASA Astrophysics Data System (ADS)

Lucey, Paul G.; Trang, David; Johnson, Jeffrey R.; Glotch, Timothy D.

2018-01-01

Several studies have detected the presence of nanophase ferric oxide, such as nanophase hematite, across the martian surface through spacecraft and rover data. In this study, we used the radiative transfer method to detect and quantify the abundance of these nanophase particles. Because the visible/near-infrared spectral characteristics of hematite > 10 nm in size are different from nanophase hematite < 10 nm, there are not any adequate optical constants of nanophase hematite to study visible to near-infrared rover/spacecraft data of the martian surface. Consequently, we found that radiative transfer models based upon the optical constants of crystalline hematite are unable to reproduce laboratory spectra of nanophase hematite. In order to match the model spectra to the laboratory spectra, we developed a new set of optical constants of nanophase hematite in the visible and near-infrared and found that radiative transfer models based upon these optical constants consistently model the laboratory spectra. We applied our model to the passive bidirectional reflectance spectra data from the Chemistry and Camera (ChemCam) instrument onboard the Mars Science Laboratory rover, Curiosity. After modeling six spectra representing different major units identified during the first year of rover operations, we found that the nanophase hematite abundance was no more than 4 wt%.

Simulating the Risk of Liver Fluke Infection using a Mechanistic Hydro-epidemiological Model

NASA Astrophysics Data System (ADS)

Beltrame, Ludovica; Dunne, Toby; Rose, Hannah; Walker, Josephine; Morgan, Eric; Vickerman, Peter; Wagener, Thorsten

2016-04-01

Liver Fluke (Fasciola hepatica) is a common parasite found in livestock and responsible for considerable economic losses throughout the world. Risk of infection is strongly influenced by climatic and hydrological conditions, which characterise the host environment for parasite development and transmission. Despite on-going control efforts, increases in fluke outbreaks have been reported in recent years in the UK, and have been often attributed to climate change. Currently used fluke risk models are based on empirical relationships derived between historical climate and incidence data. However, hydro-climate conditions are becoming increasingly non-stationary due to climate change and direct anthropogenic impacts such as land use change, making empirical models unsuitable for simulating future risk. In this study we introduce a mechanistic hydro-epidemiological model for Liver Fluke, which explicitly simulates habitat suitability for disease development in space and time, representing the parasite life cycle in connection with key environmental conditions. The model is used to assess patterns of Liver Fluke risk for two catchments in the UK under current and potential future climate conditions. Comparisons are made with a widely used empirical model employing different datasets, including data from regional veterinary laboratories. Results suggest that mechanistic models can achieve adequate predictive ability and support adaptive fluke control strategies under climate change scenarios.

Adequate antiplatelet regimen in patients on chronic anti-vitamin K treatment undergoing percutaneous coronary intervention

PubMed Central

Brugaletta, Salvatore; Martin-Yuste, Victoria; Ferreira-González, Ignacio; Cola, Clarissa; Alvarez-Contreras, Luis; Antonio, Marta De; Garcia-Moll, Xavier; García-Picart, Joan; Martí, Vicens; Balcells-Iranzo, Jordi; Sabaté, Manel

2011-01-01

AIM: To investigate the impact of dual antiplatelet therapy (DAT) in patients on anti-vitamin K (AVK) regimen requiring percutaneous coronary intervention (PCI). METHODS: Between February 2006 and February 2008, 138 consecutive patients under chronic AVK treatment were enrolled in this registry. Of them, 122 received bare metal stent implantation and 16 received drug eluting stent implantation. The duration of DAT, on top of AVK treatment, was decided at the discretion of the clinician. Adequate duration of DAT was defined according to type of stent implanted and to its clinical indication. RESULTS: The baseline clinical characteristics of patients reflect their high risk, with high incidence of comorbid conditions (Charlson score ≥ 3 in 89% of the patients). At a mean follow-up of 17 ± 11 mo, 22.9% of patients developed a major adverse cardiac event (MACE): 12.6% died from cardiovascular disease and almost 6% had an acute myocardial infarction. Major hemorrhagic events were observed in 7.4%. Adequate DAT was obtained in only 44% of patients. In the multivariate analysis, no adequate DAT and Charlson score were the only independent predictors of MACE (both P = 0.02). CONCLUSION: Patients on chronic AVK therapy represent a high risk population and suffer from a high MACE rate after PCI. An adequate DAT regimen and absence of comorbid conditions are strongly associated with better clinical outcomes. PMID:22125672

Iodine Status of Women of Reproductive Age in Sierra Leone and Its Association with Household Coverage with Adequately Iodized Salt

PubMed Central

Rohner, Fabian; Wirth, James P.; Woodruff, Bradley A.; Chiwile, Faraja; Yankson, Hannah; Sesay, Fatmata; Koroma, Aminata S.; Petry, Nicolai; Pyne-Bailey, Solade; Dominguez, Elisa; Kupka, Roland; Hodges, Mary H.; de Onis, Mercedes

2016-01-01

Salt iodization programs are a public health success in tackling iodine deficiency. Yet, a large proportion of the world’s population remains at risk for iodine deficiency. In a nationally representative cross-sectional survey in Sierra Leone, household salt samples and women’s urine samples were quantitatively analyzed for iodine content. Salt was collected from 1123 households, and urine samples from 817 non-pregnant and 154 pregnant women. Household coverage with adequately iodized salt (≥15 mg/kg iodine) was 80.7%. The median urinary iodine concentration (UIC) of pregnant women was 175.8 µg/L and of non-pregnant women 190.8 µg/L. Women living in households with adequately iodized salt had higher median UIC (for pregnant women: 180.6 µg/L vs. 100.8 µg/L, respectively, p < 0.05; and for non-pregnant women: 211.3 µg/L vs. 97.8 µg/L, p < 0.001). Differences in UIC by residence, region, household wealth, and women’s education were much smaller in women living in households with adequately iodized salt than in households without. Despite the high household coverage of iodized salt in Sierra Leone, it is important to reach the 20% of households not consuming adequately iodized salt. Salt iodization has the potential for increasing equity in iodine status even with the persistence of other risk factors for deficiency. PMID:26848685

Simulation loop between cad systems, GEANT-4 and GeoModel: Implementation and results

NASA Astrophysics Data System (ADS)

Sharmazanashvili, A.; Tsutskiridze, Niko

2016-09-01

Compare analysis of simulation and as-built geometry descriptions of detector is important field of study for data_vs_Monte-Carlo discrepancies. Shapes consistency and detalization is not important while adequateness of volumes and weights of detector components are essential for tracking. There are 2 main reasons of faults of geometry descriptions in simulation: (1) Difference between simulated and as-built geometry descriptions; (2) Internal inaccuracies of geometry transformations added by simulation software infrastructure itself. Georgian Engineering team developed hub on the base of CATIA platform and several tools enabling to read in CATIA different descriptions used by simulation packages, like XML->CATIA; VP1->CATIA; Geo-Model->CATIA; Geant4->CATIA. As a result it becomes possible to compare different descriptions with each other using the full power of CATIA and investigate both classes of reasons of faults of geometry descriptions. Paper represents results of case studies of ATLAS Coils and End-Cap toroid structures.

An expanded model of the moral self: Beyond care and justice.

PubMed

Miles, Andrew; Upenieks, Laura

2018-05-01

Most research on moral identities conceptualizes morality exclusively in terms of care and justice, but work from across the social sciences indicates that these represent only a corner of the moral landscape. Emphasizing care and justice alone severely restricts the scope of moral identity models, and risks under-estimating the influence of moral self-processes. To address this, we develop and validate measures of moral identity focused on group loyalty, authority, and purity, three additional facets of morality highlighted in Moral Foundations Theory. Although the loyalty identity is remarkably similar to the care/justice identity, the authority and purity identities are distinct, and demonstrate adequate convergent, divergent, and nomological validity. These identities also predict a wide range of behaviors that traditional care/justice focused moral identities miss. Taken together, our work indicates that the moral self is more complex - and has a much wider scope of influence - than previously supposed. Copyright © 2018 Elsevier Inc. All rights reserved.

Preparation and characterization of a novel graphene/biochar composite for aqueous phenanthrene and mercury removal.

PubMed

Tang, Jingchun; Lv, Honghong; Gong, Yanyan; Huang, Yao

2015-11-01

A graphene/biochar composite (G/BC) was synthesized via slow pyrolysis of graphene (G) pretreated wheat straw, and tested for the sorption characteristics and mechanisms of representative aqueous contaminants (phenanthrene and mercury). Structure and morphology analysis showed that G was coated on the surface of biochar (BC) mainly through π-π interactions, resulting in a larger surface area, more functional groups, greater thermal stability, and higher removal efficiency of phenanthrene and mercury compared to BC. Pseudo second-order model adequately simulated sorption kinetics, and sorption isotherms of phenanthrene and mercury were simulated well by dual-mode and BET models, respectively. FTIR and SEM analysis suggested that partitioning and surface sorption were dominant mechanisms for phenanthrene sorption, and that surface complexation between mercury and C-O, CC, -OH, and OC-O functional groups was responsible for mercury removal. The results suggested that the G/BC composite is an efficient, economic, and environmentally friendly multifunctional adsorbent for environmental remediation. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Development of indicators for evaluating public dental healthcare services].

PubMed

Bueno, Vera Lucia Ribeiro de Carvalho; Cordoni Júnior, Luiz; Mesas, Arthur Eumann

2011-07-01

The objective of this article is to describe and analyze the development of indicators used to identify strengths and deficiencies in public dental healthcare services in the municipality of Cambé, Paraná. The methodology employed was a historical-organizational case study. A theoretical model of the service was developed for evaluation planning. To achieve this, information was collected from triangulation of methods (interviews, document analysis and observation). A matrix was then developed which presents analysis dimensions, criteria, indicators, punctuation, parameters and sources of information. Three workshops were staged during the process with local service professionals in order to verify whether both the logical model and the matrix represented the service adequately. The period for collecting data was from November 2006 through July, 2007. As a result, a flowchart of the organization of the public dental health service and a matrix with two-dimensional analysis, twelve criteria and twenty-four indicators, was developed. The development of indicators favoring the participation of people involved with the practice has enabled more comprehensive and realistic evaluation planning.

Global multiresolution models of surface wave propagation: comparing equivalently regularized Born and ray theoretical solutions

NASA Astrophysics Data System (ADS)

Boschi, Lapo

2006-10-01

I invert a large set of teleseismic phase-anomaly observations, to derive tomographic maps of fundamental-mode surface wave phase velocity, first via ray theory, then accounting for finite-frequency effects through scattering theory, in the far-field approximation and neglecting mode coupling. I make use of a multiple-resolution pixel parametrization which, in the assumption of sufficient data coverage, should be adequate to represent strongly oscillatory Fréchet kernels. The parametrization is finer over North America, a region particularly well covered by the data. For each surface-wave mode where phase-anomaly observations are available, I derive a wide spectrum of plausible, differently damped solutions; I then conduct a trade-off analysis, and select as optimal solution model the one associated with the point of maximum curvature on the trade-off curve. I repeat this exercise in both theoretical frameworks, to find that selected scattering and ray theoretical phase-velocity maps are coincident in pattern, and differ only slightly in amplitude.

Contributions of computational chemistry and biophysical techniques to fragment-based drug discovery.

PubMed

Gozalbes, Rafael; Carbajo, Rodrigo J; Pineda-Lucena, Antonio

2010-01-01

In the last decade, fragment-based drug discovery (FBDD) has evolved from a novel approach in the search of new hits to a valuable alternative to the high-throughput screening (HTS) campaigns of many pharmaceutical companies. The increasing relevance of FBDD in the drug discovery universe has been concomitant with an implementation of the biophysical techniques used for the detection of weak inhibitors, e.g. NMR, X-ray crystallography or surface plasmon resonance (SPR). At the same time, computational approaches have also been progressively incorporated into the FBDD process and nowadays several computational tools are available. These stretch from the filtering of huge chemical databases in order to build fragment-focused libraries comprising compounds with adequate physicochemical properties, to more evolved models based on different in silico methods such as docking, pharmacophore modelling, QSAR and virtual screening. In this paper we will review the parallel evolution and complementarities of biophysical techniques and computational methods, providing some representative examples of drug discovery success stories by using FBDD.

Watching ultrafast responses of structure and magnetism in condensed matter with momentum-resolved probes

PubMed Central

Johnson, S. L.; Savoini, M.; Beaud, P.; Ingold, G.; Staub, U.; Carbone, F.; Castiglioni, L.; Hengsberger, M.; Osterwalder, J.

2017-01-01

We present a non-comprehensive review of some representative experimental studies in crystalline condensed matter systems where the effects of intense ultrashort light pulses are probed using x-ray diffraction and photoelectron spectroscopy. On an ultrafast (sub-picosecond) time scale, conventional concepts derived from the assumption of thermodynamic equilibrium must often be modified in order to adequately describe the time-dependent changes in material properties. There are several commonly adopted approaches to this modification, appropriate in different experimental circumstances. One approach is to treat the material as a collection of quasi-thermal subsystems in thermal contact with each other in the so-called “N-temperature” models. On the other extreme, one can also treat the time-dependent changes as fully coherent dynamics of a sometimes complex network of excitations. Here, we present examples of experiments that fall into each of these categories, as well as experiments that partake of both models. We conclude with a discussion of the limitations and future potential of these concepts. PMID:29308418

Statistical analysis and isotherm study of uranium biosorption by Padina sp. algae biomass.

PubMed

Khani, Mohammad Hassan

2011-06-01

The application of response surface methodology is presented for optimizing the removal of U ions from aqueous solutions using Padina sp., a brown marine algal biomass. Box-Wilson central composite design was employed to assess individual and interactive effects of the four main parameters (pH and initial uranium concentration in solutions, contact time and temperature) on uranium uptake. Response surface analysis showed that the data were adequately fitted to second-order polynomial model. Analysis of variance showed a high coefficient of determination value (R (2)=0.9746) and satisfactory second-order regression model was derived. The optimum pH and initial uranium concentration in solutions, contact time and temperature were found to be 4.07, 778.48 mg/l, 74.31 min, and 37.47°C, respectively. Maximized uranium uptake was predicted and experimentally validated. The equilibrium data for biosorption of U onto the Padina sp. were well represented by the Langmuir isotherm, giving maximum monolayer adsorption capacity as high as 376.73 mg/g.

Development and initial validation of an Aviation Safety Climate Scale.

PubMed

Evans, Bronwyn; Glendon, A Ian; Creed, Peter A

2007-01-01

A need was identified for a consistent set of safety climate factors to provide a basis for aviation industry benchmarking. Six broad safety climate themes were identified from the literature and consultations with industry safety experts. Items representing each of the themes were prepared and administered to 940 Australian commercial pilots. Data from half of the sample (N=468) were used in an exploratory factor analysis that produced a 3-factor model of Management commitment and communication, Safety training and equipment, and Maintenance. A confirmatory factor analysis on the remaining half of the sample showed the 3-factor model to be an adequate fit to the data. The results of this study have produced a scale of safety climate for aviation that is both reliable and valid. This study developed a tool to assess the level of perceived safety climate, specifically of pilots, but may also, with minor modifications, be used to assess other groups' perceptions of safety climate.

Can Aerosol Offset Urban Heat Island Effect?

NASA Astrophysics Data System (ADS)

Jin, M. S.; Shepherd, J. M.

2009-12-01

The Urban Heat Island effect (UHI) refers to urban skin or air temperature exceeding the temperatures in surrounding non-urban regions. In a warming climate, the UHI may intensify extreme heat waves and consequently cause significant health and energy problems. Aerosols reduce surface insolation via the direct effect, namely, scattering and absorbing sunlight in the atmosphere. Combining the National Aeronautics and Space Administration (NASA) AERONET (AErosol RObotic NETwork) observations over large cities together with Weather Research and Forecasting Model (WRF) simulations, we find that the aerosol direct reduction of surface insolation range from 40-100 Wm-2, depending on seasonality and aerosol loads. As a result, surface skin temperature can be reduced by 1-2C while 2-m surface air temperature by 0.5-1C. This study suggests that the aerosol direct effect is a competing mechanism for the urban heat island effect (UHI). More importantly, both aerosol and urban land cover effects must be adequately represented in meteorological and climate modeling systems in order to properly characterize urban surface energy budgets and UHI.

Breast Radiotherapy with Mixed Energy Photons; a Model for Optimal Beam Weighting.

PubMed

Birgani, Mohammadjavad Tahmasebi; Fatahiasl, Jafar; Hosseini, Seyed Mohammad; Bagheri, Ali; Behrooz, Mohammad Ali; Zabiehzadeh, Mansour; Meskani, Reza; Gomari, Maryam Talaei

2015-01-01

Utilization of high energy photons (>10 MV) with an optimal weight using a mixed energy technique is a practical way to generate a homogenous dose distribution while maintaining adequate target coverage in intact breast radiotherapy. This study represents a model for estimation of this optimal weight for day to day clinical usage. For this purpose, treatment planning computed tomography scans of thirty-three consecutive early stage breast cancer patients following breast conservation surgery were analyzed. After delineation of the breast clinical target volume (CTV) and placing opposed wedge paired isocenteric tangential portals, dosimeteric calculations were conducted and dose volume histograms (DVHs) were generated, first with pure 6 MV photons and then these calculations were repeated ten times with incorporating 18 MV photons (ten percent increase in weight per step) in each individual patient. For each calculation two indexes including maximum dose in the breast CTV (Dmax) and the volume of CTV which covered with 95% Isodose line (VCTV, 95%IDL) were measured according to the DVH data and then normalized values were plotted in a graph. The optimal weight of 18 MV photons was defined as the intersection point of Dmax and VCTV, 95%IDL graphs. For creating a model to predict this optimal weight multiple linear regression analysis was used based on some of the breast and tangential field parameters. The best fitting model for prediction of 18 MV photons optimal weight in breast radiotherapy using mixed energy technique, incorporated chest wall separation plus central lung distance (Adjusted R2=0.776). In conclusion, this study represents a model for the estimation of optimal beam weighting in breast radiotherapy using mixed photon energy technique for routine day to day clinical usage.

Uncertainty and Intelligence in Computational Stochastic Mechanics

NASA Technical Reports Server (NTRS)

Ayyub, Bilal M.

1996-01-01

Classical structural reliability assessment techniques are based on precise and crisp (sharp) definitions of failure and non-failure (survival) of a structure in meeting a set of strength, function and serviceability criteria. These definitions are provided in the form of performance functions and limit state equations. Thus, the criteria provide a dichotomous definition of what real physical situations represent, in the form of abrupt change from structural survival to failure. However, based on observing the failure and survival of real structures according to the serviceability and strength criteria, the transition from a survival state to a failure state and from serviceability criteria to strength criteria are continuous and gradual rather than crisp and abrupt. That is, an entire spectrum of damage or failure levels (grades) is observed during the transition to total collapse. In the process, serviceability criteria are gradually violated with monotonically increasing level of violation, and progressively lead into the strength criteria violation. Classical structural reliability methods correctly and adequately include the ambiguity sources of uncertainty (physical randomness, statistical and modeling uncertainty) by varying amounts. However, they are unable to adequately incorporate the presence of a damage spectrum, and do not consider in their mathematical framework any sources of uncertainty of the vagueness type. Vagueness can be attributed to sources of fuzziness, unclearness, indistinctiveness, sharplessness and grayness; whereas ambiguity can be attributed to nonspecificity, one-to-many relations, variety, generality, diversity and divergence. Using the nomenclature of structural reliability, vagueness and ambiguity can be accounted for in the form of realistic delineation of structural damage based on subjective judgment of engineers. For situations that require decisions under uncertainty with cost/benefit objectives, the risk of failure should depend on the underlying level of damage and the uncertainties associated with its definition. A mathematical model for structural reliability assessment that includes both ambiguity and vagueness types of uncertainty was suggested to result in the likelihood of failure over a damage spectrum. The resulting structural reliability estimates properly represent the continuous transition from serviceability to strength limit states over the ultimate time exposure of the structure. In this section, a structural reliability assessment method based on a fuzzy definition of failure is suggested to meet these practical needs. A failure definition can be developed to indicate the relationship between failure level and structural response. In this fuzzy model, a subjective index is introduced to represent all levels of damage (or failure). This index can be interpreted as either a measure of failure level or a measure of a degree of belief in the occurrence of some performance condition (e.g., failure). The index allows expressing the transition state between complete survival and complete failure for some structural response based on subjective evaluation and judgment.

Mesoscopic modeling and parameter estimation of a lithium-ion battery based on LiFePO4/graphite

NASA Astrophysics Data System (ADS)

Jokar, Ali; Désilets, Martin; Lacroix, Marcel; Zaghib, Karim

2018-03-01

A novel numerical model for simulating the behavior of lithium-ion batteries based on LiFePO4(LFP)/graphite is presented. The model is based on the modified Single Particle Model (SPM) coupled to a mesoscopic approach for the LFP electrode. The model comprises one representative spherical particle as the graphite electrode, and N LFP units as the positive electrode. All the SPM equations are retained to model the negative electrode performance. The mesoscopic model rests on non-equilibrium thermodynamic conditions and uses a non-monotonic open circuit potential for each unit. A parameter estimation study is also carried out to identify all the parameters needed for the model. The unknown parameters are the solid diffusion coefficient of the negative electrode (Ds,n), reaction-rate constant of the negative electrode (Kn), negative and positive electrode porosity (εn&εn), initial State-Of-Charge of the negative electrode (SOCn,0), initial partial composition of the LFP units (yk,0), minimum and maximum resistance of the LFP units (Rmin&Rmax), and solution resistance (Rcell). The results show that the mesoscopic model can simulate successfully the electrochemical behavior of lithium-ion batteries at low and high charge/discharge rates. The model also describes adequately the lithiation/delithiation of the LFP particles, however, it is computationally expensive compared to macro-based models.

[Service productivity in hospital nursing--conceptual framework of a productivity analysis].

PubMed

Thomas, D; Borchert, M; Brockhaus, N; Jäschke, L; Schmitz, G; Wasem, J

2015-01-01

Decreasing staff numbers compounded by an increasing number of cases is regarded as main challenge in German hospital nursing. These input reductions accompanied by output extensions imply that hospital nursing services have had to achieve a continuous productivity growth in the recent years. Appropriately targeted productivity enhancements require approved and effective methods for productivity acquisition and measurement. However, there is a lack of suitable productivity measurement instruments for hospital nursing services. This deficit is addressed in the present study by the development of an integrated productivity model for hospital nursing services. Conceptually, qualitative as well as quantitative aspects of nursing services productivity are equally taken into consideration. Based on systematic literature reviews different conceptual frameworks of service productivity and the current state of research in hospital nursing services productivity were analysed. On this basis nursing sensitive inputs, processes and outputs were identified and integrated into a productivity model. As an adequate framework for a hospital nursing services productivity model the conceptual approach by Grönroos/Ojasalo was identified. The basic structure of this model was adapted stepwise to our study purpose by integrating theoretical and empirical findings from the research fields of service productivity, nursing productivity as well as national and international nursing research. Special challenges existed concerning the identification of relevant influencing factors as well as the representation of nursing sensitive outputs. The final result is an integrated productivity model, which can be used as an adequate framework for further research in hospital nursing productivity. Research on hospital nursing services productivity is rare, especially in Germany. The conceptual framework developed in this study builds on established knowledge in service productivity research. The theoretical findings have been advanced and adapted to the context of German hospital nursing services. The presented productivity model represents a unique combination of services and nursing services research, which did not exist so far. By operationalisation of the model's components it can be used as the basis for further empirical -research. © Georg Thieme Verlag KG Stuttgart · New York.

Monitoring of Ritz modal generation

NASA Technical Reports Server (NTRS)

Chargin, Mladen; Butler, Thomas G.

1990-01-01

A scheme is proposed to monitor the adequacy of a set of Ritz modes to represent a solution by comparing the quantity generated with certain properties involving the forcing function. In so doing an attempt was made to keep this algorithm lean and efficient, so that it will be economical to apply. Using this monitoring scheme during Ritz Mode generation will automatically ensure that the k Ritz modes theta k that are generated are adequate to represent both the spatial and temporal behavior of the structure when forced under the given transient condition defined by F(s,t).

Removal of Procion Red dye from colored effluents using H2SO4-/HNO3-treated avocado shells (Persea americana) as adsorbent.

PubMed

Georgin, Jordana; da Silva Marques, Bianca; da Silveira Salla, Julia; Foletto, Edson Luiz; Allasia, Daniel; Dotto, Guilherme Luiz

2018-03-01

The treatment of colored effluents containing Procion Red dye (PR) was investigated using H 2 SO 4 and HNO 3 modified avocado shells (Persea americana) as adsorbents. The adsorbent materials (AS-H 2 SO 4 and AS-HNO 3 ) were properly characterized. The adsorption study was carried out considering the effects of adsorbent dosage and pH. Kinetic, equilibrium, and thermodynamic aspects were also evaluated. Finally, the adsorbents were tested to treat simulated dye house effluents. For both materials, the adsorption was favored using 0.300 g L -1 of adsorbent at pH 6.5, where, more than 90% of PR was removed from the solution. General order model was able to explain the adsorption kinetics for both adsorbents. The Sips model was adequate to represent the isotherm data, being the maximum adsorption capacities of 167.0 and 212.6 mg g -1 for AS-H 2 SO 4 and AS-HNO 3 , respectively. The adsorption processes were thermodynamically spontaneous, favorable (- 17.0 < ΔG 0  < - 13.2 kJ mol -1 ), and exothermic (ΔH 0 values of - 29 and - 55 kJ mol -1 ). AS-H 2 SO 4 and AS-HNO 3 were adequate to treat dye house effluents, attaining color removal percentages of 82 and 75%. Avocado shells, after a simple acid treatment, can be a low-cost option to treat colored effluents.

There's something about Molly: The underresearched yet popular powder form of ecstasy in the United States.

PubMed

Palamar, Joseph J

2017-01-01

Molly has been the street name for powder or crystalline ecstasy (3,4-methylenedioxymethamphetamine [MDMA]) in the United States since the early 2000s; however, few studies have examined Molly use or included Molly in the definition of ecstasy/MDMA. Prevalence of self-reported ecstasy use is being underreported on surveys due to the lack of inclusion of "Molly," although Molly is often so adulterated with novel psychoactive substances such as synthetic cathinones ("bath salts") that the name "Molly" may no longer adequately represent ecstasy/MDMA. The author recommends that Molly use and Molly purity be further studied to more adequately inform prevention and harm reduction.

Neuroendocrine Derangements in Early Septic Shock: Pharmacotherapy for Relative Adrenal and Vasopressin Insufficiency.

PubMed

Schurr, James W; Szumita, Paul M; DeGrado, Jeremy R

2017-09-01

Septic shock is a leading cause of mortality in intensive care units throughout the world. While this disease state represents a highly complex pathophysiology involving numerous organ systems, the early approach to care includes adequate hemodynamic support traditionally achieved via infusions of vasoactive medications after adequate fluid resuscitation. Relative adrenal and vasopressin deficiencies are a common feature of septic shock that contribute to impaired hemodynamics. Hydrocortisone and vasopressin are endocrine system hormone analogues that target the acute neuroendocrine imbalance associated with septic shock. This clinically focused annotated review describes the pathophysiological mechanisms behind their use and explores the potential clinical roles of early administration and synergy when combined.

The parameters of death: a consideration of the quantity of information in a life table using a polynomial representation of the survivorship curve.

PubMed

Anson, J

1988-08-01

How much unique information is contained in any life table? The logarithmic survivorship (lx) columns of 360 empirical life tables were fitted by a weighted fifth degree polynomial, and it is shown that six parameters are adequate to reproduce these curves almost flawlessly. However, these parameters are highly intercorrelated, so that a two-dimensional representation would be adequate to express the similarities and differences among life tables. It is thus concluded that a life table contains but two unique pieces of information, these being the level of mortality in the population which it represents, and the relative shape of the underlying mortality curve.

Legacy nutrient dynamics and patterns of catchment response under changing land use and management

NASA Astrophysics Data System (ADS)

Attinger, S.; Van, M. K.; Basu, N. B.

2017-12-01

Watersheds are complex heterogeneous systems that store, transform, and release water and nutrients under a broad distribution of both natural and anthropogenic controls. Many current watershed models, from complex numerical models to simpler reservoir-type models, are considered to be well-developed in their ability to predict fluxes of water and nutrients to streams and groundwater. They are generally less adept, however, at capturing watershed storage dynamics. In other words, many current models are run with an assumption of steady-state dynamics, and focus on nutrient flows rather than changes in nutrient stocks within watersheds. Although these commonly used modeling approaches may be able to adequately capture short-term watershed dynamics, they are unable to represent the clear nonlinearities or hysteresis responses observed in watersheds experiencing significant changes in nutrient inputs. To address such a lack, we have, in the present work, developed a parsimonious modeling approach designed to capture long-term catchment responses to spatial and temporal changes in nutrient inputs. In this approach, we conceptualize the catchment as a biogeochemical reactor that is driven by nutrient inputs, characterized internally by both biogeochemical degradation and residence or travel time distributions, resulting in a specific nutrient output. For the model simulations, we define a range of different scenarios to represent real-world changes in land use and management implemented to improve water quality. We then introduce the concept of state-space trajectories to describe system responses to these potential changes in anthropogenic forcings. We also increase model complexity, in a stepwise fashion, by dividing the catchment into multiple biogeochemical reactors, coupled in series or in parallel. Using this approach, we attempt to answer the following questions: (1) What level of model complexity is needed to capture observed system responses? (2) How can we explain different patterns of nonlinearity in watershed nutrient dynamics? And finally, how does the accumulation of nutrient legacies within watersheds impact current and future water quality?

Strategic workforce planning for a multihospital, integrated delivery system.

PubMed

Datz, David; Hallberg, Colleen; Harris, Kathy; Harrison, Lisa; Samples, Patience

2012-01-01

Banner Health has long recognized the need to anticipate, beyond the immediate operational realities or even the annual budgeting projection exercises, the necessary workforce needs of the future. Thus, in 2011, Banner implemented a workforce planning model that included structures, processes, and tools for predicting workforce needs, with particular focus on identified critical systemwide practice areas. The model represents the incorporation of labor management tools and processes with more strategic, broad-view, long-term assessment and planning mechanisms. The sequential tying of the workforce planning lifecycle with the organization's strategy and financial planning process supports alignment of goals, objectives, and resource allocation. Collaboration among strategy, finance, human resources, and operations has provided us with the ability to identify critical position groups based on 3-year strategic priorities. By engaging leaders from across the organization, focusing on activities at facility, regional, and system levels, and building in mechanisms for accountability, we are now engaged in continuous evaluations of our delivery models, the competencies and preparations necessary for the staff to effectively function within those delivery models, and developing and implementing action plans designed to ensure adequate numbers of the staff whose competencies will be suited to the work expected of them.

Molecular-dynamics simulation of mutual diffusion in nonideal liquid mixtures

NASA Astrophysics Data System (ADS)

Rowley, R. L.; Stoker, J. M.; Giles, N. F.

1991-05-01

The mutual-diffusion coefficients, D 12, of n-hexane, n-heptane, and n-octane in chloroform were modeled using equilibrium molecular-dynamics (MD) simulations of simple Lennard-Jones (LJ) fluids. Pure-component LJ parameters were obtained by comparison of simulations to experimental self-diffusion coefficients. While values of “effective” LJ parameters are not expected to simulate accurately diverse thermophysical properties over a wide range of conditions, it was recently shown that effective parameters obtained from pure self-diffusion coefficients can accurately model mutual diffusion in ideal, liquid mixtures. In this work, similar simulations are used to model diffusion in nonideal mixtures. The same combining rules used in the previous study for the cross-interaction parameters were found to be adequate to represent the composition dependence of D 12. The effect of alkane chain length on D 12 is also correctly predicted by the simulations. A commonly used assumption in empirical correlations of D 12, that its kinetic portion is a simple, compositional average of the intradiffusion coefficients, is inconsistent with the simulation results. In fact, the value of the kinetic portion of D 12 was often outside the range of values bracketed by the two intradiffusion coefficients for the nonideal system modeled here.

Towards a fully self-consistent inversion combining historical and paleomagnetic data for geomagnetic field reconstructions

NASA Astrophysics Data System (ADS)

Arneitz, P.; Leonhardt, R.; Fabian, K.; Egli, R.

2017-12-01

Historical and paleomagnetic data are the two main sources of information about the long-term geomagnetic field evolution. Historical observations extend to the late Middle Ages, and prior to the 19th century, they consisted mainly of pure declination measurements from navigation and orientation logs. Field reconstructions going back further in time rely solely on magnetization acquired by rocks, sediments, and archaeological artefacts. The combined dataset is characterized by a strongly inhomogeneous spatio-temporal distribution and highly variable data reliability and quality. Therefore, an adequate weighting of the data that correctly accounts for data density, type, and realistic error estimates represents the major challenge for an inversion approach. Until now, there has not been a fully self-consistent geomagnetic model that correctly recovers the variation of the geomagnetic dipole together with the higher-order spherical harmonics. Here we present a new geomagnetic field model for the last 4 kyrs based on historical, archeomagnetic and volcanic records. The iterative Bayesian inversion approach targets the implementation of reliable error treatment, which allows different record types to be combined in a fully self-consistent way. Modelling results will be presented along with a thorough analysis of model limitations, validity and sensitivity.

Solvent refined coal (SRC) process. Annual technical progress report, January 1979-December 1979

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

Not Available

1980-11-01

A set of statistically designed experiments was used to study the effects of several important operating variables on coal liquefaction product yield structures. These studies used a Continuous Stirred-Tank Reactor to provide a hydrodynamically well-defined system from which kinetic data could be extracted. An analysis of the data shows that product yield structures can be adequately represented by a correlative model. It was shown that second-order effects (interaction and squared terms) are necessary to provide a good model fit of the data throughout the range studied. Three reports were issued covering the SRC-II database and yields as functions of operatingmore » variables. The results agree well with the generally-held concepts of the SRC reaction process, i.e., liquid phase hydrogenolysis of liquid coal which is time-dependent, thermally activated, catalyzed by recycle ash, and reaction rate-controlled. Four reports were issued summarizing the comprehensive SRC reactor thermal response models and reporting the results of several studies made with the models. Analytical equipment for measuring SRC off-gas composition and simulated distillation of coal liquids and appropriate procedures have been established.« less

Multivariate normality

NASA Technical Reports Server (NTRS)

Crutcher, H. L.; Falls, L. W.

1976-01-01

Sets of experimentally determined or routinely observed data provide information about the past, present and, hopefully, future sets of similarly produced data. An infinite set of statistical models exists which may be used to describe the data sets. The normal distribution is one model. If it serves at all, it serves well. If a data set, or a transformation of the set, representative of a larger population can be described by the normal distribution, then valid statistical inferences can be drawn. There are several tests which may be applied to a data set to determine whether the univariate normal model adequately describes the set. The chi-square test based on Pearson's work in the late nineteenth and early twentieth centuries is often used. Like all tests, it has some weaknesses which are discussed in elementary texts. Extension of the chi-square test to the multivariate normal model is provided. Tables and graphs permit easier application of the test in the higher dimensions. Several examples, using recorded data, illustrate the procedures. Tests of maximum absolute differences, mean sum of squares of residuals, runs and changes of sign are included in these tests. Dimensions one through five with selected sample sizes 11 to 101 are used to illustrate the statistical tests developed.

Multivariate model of female black bear habitat use for a Geographic Information System

USGS Publications Warehouse

Clark, Joseph D.; Dunn, James E.; Smith, Kimberly G.

1993-01-01

Simple univariate statistical techniques may not adequately assess the multidimensional nature of habitats used by wildlife. Thus, we developed a multivariate method to model habitat-use potential using a set of female black bear (Ursus americanus) radio locations and habitat data consisting of forest cover type, elevation, slope, aspect, distance to roads, distance to streams, and forest cover type diversity score in the Ozark Mountains of Arkansas. The model is based on the Mahalanobis distance statistic coupled with Geographic Information System (GIS) technology. That statistic is a measure of dissimilarity and represents a standardized squared distance between a set of sample variates and an ideal based on the mean of variates associated with animal observations. Calculations were made with the GIS to produce a map containing Mahalanobis distance values within each cell on a 60- × 60-m grid. The model identified areas of high habitat use potential that could not otherwise be identified by independent perusal of any single map layer. This technique avoids many pitfalls that commonly affect typical multivariate analyses of habitat use and is a useful tool for habitat manipulation or mitigation to favor terrestrial vertebrates that use habitats on a landscape scale.

Using Passive Sampling to Asses Ozone Formation in Sparsely Monitored Areas

NASA Astrophysics Data System (ADS)

Crosby, C. M.; Mainord, J.; George, L. A.

2016-12-01

Tropospheric ozone (O3), a secondary pollutant, is detrimental to both human health and the environment. O3 is formed from nitrogen oxides (NOx) and volatile organic compounds, (VOC's) in the presence of sunlight. Hermiston is a low population rural city in Oregon (17,707), where O3 levels are expected to be minimal. However, Hermiston has recently experienced elevated O3 concentrations, approaching EPA levels of non-attainment. These levels were not predicted by airshed modeling of the region, suggesting that precursor emissions are not adequately represented in the model. Due to the limited monitoring in the area, there are no measurements of precursors in the region. In this study, passive Ogawa samplers were used to measure NOx and O3 levels at twenty sites in the area. The concentrations were then mapped in conjunction with wind trajectories derived from HYSPLIT and compared to NOx point sources attained from the National Emissions Inventory (NEI). The measurement campaign revealed areas of elevated NOx concentrations that were not accounted for in the airshed model. Further exploration is needed to identify these sources. This study lays groundwork for the use of passive sampling to ground-truth airshed models in the absence of monitoring networks.

Do prevailing XAD extraction methods used to generate extracts from disinfected water adequately link extract toxicology to disinfected water chemistry?

EPA Science Inventory

Motivation: It is common to use XAD resins to extract disinfection byproducts (DBPs) from disinfected water. The resulting extract is used in toxicological assays to study the effects of DBP mixtures and has been considered representative of the original disinfected water. Howeve...

43 CFR 3872.5 - Testimony at hearings to determine character of lands.

Code of Federal Regulations, 2011 CFR

2011-10-01

... (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) ADVERSE CLAIMS...; whether or not there exists within the tract or tracts claimed any lode or vein of quartz or other rock in... practicable, an adequate quantity or number of representative samples of the alleged mineral-bearing matter or...

Development and Validation of a Behavioral Screener for Preschool-Age Children

ERIC Educational Resources Information Center

DiStefano, Christine A.; Kamphaus, Randy W.

2007-01-01

The purpose of this study was to document the development of a short behavioral scale that could be used to assess preschoolers' behavior while still retaining adequate scale coverage, reliability, and validity. Factor analysis and item analysis techniques were applied to data from a nationally representative, normative database to create a…

78 FR 33886 - Identification of Ukraine as a Priority Foreign Country and Initiation of Section 301 Investigation

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-05

... Representative) identified Ukraine as a priority foreign country due to Ukraine's denial of adequate and effective protection of intellectual property rights and its denial of fair and equitable market access to... system for collecting societies, which are responsible for collecting and distributing royalties to U.S...

78 FR 15653 - Notice of Intent To Form the Commercial HVAC, WH, and Refrigeration Certification Working Group...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-12

... consensus-based negotiations among affected parties. October 2012, the convenor issued his report based on a.... Proposed Negotiating Procedures A. Key Issues for Negotiation DOE has identified the following substantive... negotiations; nevertheless, each affected interest can be adequately represented. To have a successful...

Hugs and Smiles: Demonstrating Caring in a Multicultural Early Childhood Classroom

ERIC Educational Resources Information Center

Pappamihiel, Eleni N.

2004-01-01

In many ways, teacher preparation programs have made great strides in preparing future teachers to work with an increasingly diverse population. However, there is still controversy about whether or not these courses are adequate and result in real change. This article represents a study that was designed to investigate preservice teachers' beliefs…

Development of Early Measures of Comprehension: Innovation in Individual Growth and Development Indicators

ERIC Educational Resources Information Center

Wackerle-Hollman, Alisha K.; Rodriguez, Megan I.; Bradfield, Tracy A.; Rodriguez, Michael C.; McConnell, Scott R.

2015-01-01

Early comprehension is an important, but not well-understood, contribution to early literacy and language development. Specifically, research regarding the nature of skills representative of early comprehension, including how they contribute to later reading success, is needed to support best practices to adequately prepare students. This article…

Women and Minorities in Economics Textbooks: Are They Being Adequately Represented?

ERIC Educational Resources Information Center

Robson, Denise

2001-01-01

Examines 12 recent editions of principles of economics textbooks to determine the quantity of race- and gender-related material. Finds, in general, that there has been an increase in the quantitative coverage of race- and gender-related material as measured by the number of pages, names, and tables in the textbooks. (RLH)

Behavioral interventions to promote adequate sleep among women: Protocol for a systematic review and meta-analysis

USDA-ARS?s Scientific Manuscript database

Short and poor sleep have been associated with adverse health outcomes in adults, such as overweight/obesity and type 2 diabetes, especially among women. Women therefore represent an important target for interventions aimed at improving sleep and such interventions have been advocated to enhance mat...

Quantitative Analysis of Organophosphate and Pyrethroid Insecticides, PyrethroidTransformation Products, Polybrominated Diphenyl Ethers and Bisphenol A in Residential Surface Wipe Samples

EPA Science Inventory

Surface wipe sampling is a frequently used technique for measuring persistent pollutants in residential environments. One characteristic of this form of sampling is the need to extract the entire wipe sample to achieve adequate sensitivity and to ensure representativeness. Most s...

Social Explanation and Political Accountability: Two Related Problems with a Single Solution.

ERIC Educational Resources Information Center

McPherson, Andrew; And Others

Governing bodies that are quasi-rational, representative, and democratic are accountable to those they govern in much the same way that social scientists are accountable to the academic community. Since they both appeal to rationality as the basis of their actions, governments and scientists must use epistemologically adequate procedures to…

Chapter 3. Planning and design for habitat monitoring

Treesearch

Christina D. Vojta; Lyman L. McDonald; C. Kenneth Brewer; Kevin S. McKelvey; Mary M Rowland; Michael I. Goldstein

2013-01-01

This chapter provides guidance for designing a habitat monitoring program so that it will meet the monitoring objective, will be repeatable, and will adequately represent habitat within the spatial extent of interest. Although a number of excellent resources are available for planning and designing a monitoring program for wildlife populations (e.g., Busch and Trexler...

Evaluation of seeding depth and guage-wheel load effects on maize emergence and yield

USDA-ARS?s Scientific Manuscript database

Planting represents perhaps the most important field operation with errors likely to negatively affect crop yield and thereby farm profitability. Performance of row-crop planters are evaluated by their ability to accurately place seeds into the soil at an adequate and pre-determined depth, the goal ...

The Neglected 95%: Why American Psychology Needs to Become Less American

ERIC Educational Resources Information Center

Arnett, Jeffrey J.

2008-01-01

This article proposes that psychological research published in APA journals focuses too narrowly on Americans, who comprise less than 5% of the world's population. The result is an understanding of psychology that is incomplete and does not adequately represent humanity. First, an analysis of articles published in six premier APA journals is…

Symbolic LTL Compilation for Model Checking: Extended Abstract

NASA Technical Reports Server (NTRS)

Rozier, Kristin Y.; Vardi, Moshe Y.

2007-01-01

In Linear Temporal Logic (LTL) model checking, we check LTL formulas representing desired behaviors against a formal model of the system designed to exhibit these behaviors. To accomplish this task, the LTL formulas must be translated into automata [21]. We focus on LTL compilation by investigating LTL satisfiability checking via a reduction to model checking. Having shown that symbolic LTL compilation algorithms are superior to explicit automata construction algorithms for this task [16], we concentrate here on seeking a better symbolic algorithm.We present experimental data comparing algorithmic variations such as normal forms, encoding methods, and variable ordering and examine their effects on performance metrics including processing time and scalability. Safety critical systems, such as air traffic control, life support systems, hazardous environment controls, and automotive control systems, pervade our daily lives, yet testing and simulation alone cannot adequately verify their reliability [3]. Model checking is a promising approach to formal verification for safety critical systems which involves creating a formal mathematical model of the system and translating desired safety properties into a formal specification for this model. The complement of the specification is then checked against the system model. When the model does not satisfy the specification, model-checking tools accompany this negative answer with a counterexample, which points to an inconsistency between the system and the desired behaviors and aids debugging efforts.

Initiation-promotion model of tumor prevalence in mice from space radiation exposures

NASA Technical Reports Server (NTRS)

Cucinotta, F. A.; Wilson, J. W.

1995-01-01

Exposures in space consist of low-level background components from galactic cosmic rays (GCR), occasional intense-energetic solar-particle events, periodic passes through geomagnetic-trapped radiation, and exposure from possible onboard nuclear-propulsion engines. Risk models for astronaut exposure from such diverse components and modalities must be developed to assure adequate protection in future NASA missions. The low-level background exposures (GCR), including relativistic heavy ions (HZE), will be the ultimate limiting factor for astronaut career exposure. We consider herein a two-mutation, initiation-promotion, radiation-carcinogenesis model in mice in which the initiation stage is represented by a linear kinetics model of cellular repair/misrepair, including the track-structure model for heavy ion action cross-sections. The model is validated by comparison with the harderian gland tumor experiments of Alpen et al. for various ion beams. We apply the initiation-promotion model to exposures from galactic cosmic rays, using models of the cosmic-ray environment and heavy ion transport, and consider the effects of the age of the mice prior to and after the exposure and of the length of time in space on predictions of relative risk. Our results indicate that biophysical models of age-dependent radiation hazard will provide a better understanding of GCR risk than models that rely strictly on estimates of the initial slopes of these radiations.

Simulation tools for robotics research and assessment

NASA Astrophysics Data System (ADS)

Fields, MaryAnne; Brewer, Ralph; Edge, Harris L.; Pusey, Jason L.; Weller, Ed; Patel, Dilip G.; DiBerardino, Charles A.

2016-05-01

The Robotics Collaborative Technology Alliance (RCTA) program focuses on four overlapping technology areas: Perception, Intelligence, Human-Robot Interaction (HRI), and Dexterous Manipulation and Unique Mobility (DMUM). In addition, the RCTA program has a requirement to assess progress of this research in standalone as well as integrated form. Since the research is evolving and the robotic platforms with unique mobility and dexterous manipulation are in the early development stage and very expensive, an alternate approach is needed for efficient assessment. Simulation of robotic systems, platforms, sensors, and algorithms, is an attractive alternative to expensive field-based testing. Simulation can provide insight during development and debugging unavailable by many other means. This paper explores the maturity of robotic simulation systems for applications to real-world problems in robotic systems research. Open source (such as Gazebo and Moby), commercial (Simulink, Actin, LMS), government (ANVEL/VANE), and the RCTA-developed RIVET simulation environments are examined with respect to their application in the robotic research domains of Perception, Intelligence, HRI, and DMUM. Tradeoffs for applications to representative problems from each domain are presented, along with known deficiencies and disadvantages. In particular, no single robotic simulation environment adequately covers the needs of the robotic researcher in all of the domains. Simulation for DMUM poses unique constraints on the development of physics-based computational models of the robot, the environment and objects within the environment, and the interactions between them. Most current robot simulations focus on quasi-static systems, but dynamic robotic motion places an increased emphasis on the accuracy of the computational models. In order to understand the interaction of dynamic multi-body systems, such as limbed robots, with the environment, it may be necessary to build component-level computational models to provide the necessary simulation fidelity for accuracy. However, the Perception domain remains the most problematic for adequate simulation performance due to the often cartoon nature of computer rendering and the inability to model realistic electromagnetic radiation effects, such as multiple reflections, in real-time.

Ad Hoc working group on diurnal and semi-diurnal Earth Orientation variation.

NASA Astrophysics Data System (ADS)

Gipson, J. M.

2017-12-01

Diurnal and semi-diurnal Earth orientation ("HF-EOP") variation were detected in the early 1990s in SLR and VLBI data. Beginning in 1996 a model of HF-EOP variation based on ocean-tides derived from Topex data was included in the IERS standards. This model has not been updated since then with the exception of including libration for effects for polar motion (2003 IERS conventions) and UT1 (2010 IERS conventions). The accuracy of Space Geodesy has increased remarkably over the last 20 years and the 1996 IERS HF-EOP model is no longer adequate. At the conclusion of the 2017 GGOS/IERS Unified Analysis Workshop an ad hoc working group was formed including representatives of the IDS, IGS, ILRS, and IVS. The goal of the working group is to test several models of HF-EOP in the different space geodesy techniques and to make a recommendation to the IERS for the adoption of a new HF-EOP model. In this presentation I will give a summary of work on HF-EOP done to date by various scientists which demonstrate the inadequacy of the current IERS HF-EOP model. I will then describe the goals and the progress of the working group to date, with a preview of further work.

The theory of reasoned action as parallel constraint satisfaction: towards a dynamic computational model of health behavior.

PubMed

Orr, Mark G; Thrush, Roxanne; Plaut, David C

2013-01-01

The reasoned action approach, although ubiquitous in health behavior theory (e.g., Theory of Reasoned Action/Planned Behavior), does not adequately address two key dynamical aspects of health behavior: learning and the effect of immediate social context (i.e., social influence). To remedy this, we put forth a computational implementation of the Theory of Reasoned Action (TRA) using artificial-neural networks. Our model re-conceptualized behavioral intention as arising from a dynamic constraint satisfaction mechanism among a set of beliefs. In two simulations, we show that constraint satisfaction can simultaneously incorporate the effects of past experience (via learning) with the effects of immediate social context to yield behavioral intention, i.e., intention is dynamically constructed from both an individual's pre-existing belief structure and the beliefs of others in the individual's social context. In a third simulation, we illustrate the predictive ability of the model with respect to empirically derived behavioral intention. As the first known computational model of health behavior, it represents a significant advance in theory towards understanding the dynamics of health behavior. Furthermore, our approach may inform the development of population-level agent-based models of health behavior that aim to incorporate psychological theory into models of population dynamics.

Growing C4 perennial grass for bioenergy using a new Agro-BGC ecosystem model

NASA Astrophysics Data System (ADS)

di Vittorio, A. V.; Anderson, R. S.; Miller, N. L.; Running, S. W.

2009-12-01

Accurate, spatially gridded estimates of bioenergy crop yields require 1) biophysically accurate crop growth models and 2) careful parameterization of unavailable inputs to these models. To meet the first requirement we have added the capacity to simulate C4 perennial grass as a bioenergy crop to the Biome-BGC ecosystem model. This new model, hereafter referred to as Agro-BGC, includes enzyme driven C4 photosynthesis, individual live and dead leaf, stem, and root carbon/nitrogen pools, separate senescence and litter fall processes, fruit growth, optional annual seeding, flood irrigation, a growing degree day phenology with a killing frost option, and a disturbance handler that effectively simulates fertilization, harvest, fire, and incremental irrigation. There are four Agro-BGC vegetation parameters that are unavailable for Panicum virgatum (switchgrass), and to meet the second requirement we have optimized the model across multiple calibration sites to obtain representative values for these parameters. We have verified simulated switchgrass yields against observations at three non-calibration sites in IL. Agro-BGC simulates switchgrass growth and yield at harvest very well at a single site. Our results suggest that a multi-site optimization scheme would be adequate for producing regional-scale estimates of bioenergy crop yields on high spatial resolution grids.

The Theory of Reasoned Action as Parallel Constraint Satisfaction: Towards a Dynamic Computational Model of Health Behavior

PubMed Central

Orr, Mark G.; Thrush, Roxanne; Plaut, David C.

2013-01-01

The reasoned action approach, although ubiquitous in health behavior theory (e.g., Theory of Reasoned Action/Planned Behavior), does not adequately address two key dynamical aspects of health behavior: learning and the effect of immediate social context (i.e., social influence). To remedy this, we put forth a computational implementation of the Theory of Reasoned Action (TRA) using artificial-neural networks. Our model re-conceptualized behavioral intention as arising from a dynamic constraint satisfaction mechanism among a set of beliefs. In two simulations, we show that constraint satisfaction can simultaneously incorporate the effects of past experience (via learning) with the effects of immediate social context to yield behavioral intention, i.e., intention is dynamically constructed from both an individual’s pre-existing belief structure and the beliefs of others in the individual’s social context. In a third simulation, we illustrate the predictive ability of the model with respect to empirically derived behavioral intention. As the first known computational model of health behavior, it represents a significant advance in theory towards understanding the dynamics of health behavior. Furthermore, our approach may inform the development of population-level agent-based models of health behavior that aim to incorporate psychological theory into models of population dynamics. PMID:23671603

Distinguishing between depression and anxiety: a proposal for an extension of the tripartite model.

PubMed

den Hollander-Gijsman, M E; de Beurs, E; van der Wee, N J A; van Rood, Y R; Zitman, F G

2010-05-01

The aim of the current study was to develop scales that assess symptoms of depression and anxiety and can adequately differentiate between depression and anxiety disorders, and also can distinguish within anxiety disorders. As point of departure, we used the tripartite model of Clark and Watson that discerns three dimensions: negative affect, positive affect and physiological hyperarousal. Analyses were performed on the data of 1449 patients, who completed the Mood and Anxiety Symptoms Questionnaire (MASQ) and the Brief Symptom Inventory (BSI). From this, 1434 patients were assessed with a standardized diagnostic interview. A model with five dimensions was found: depressed mood, lack of positive affect, somatic arousal, phobic fear and hostility. The scales appear capable to differentiate between patients with a mood and with an anxiety disorder. Within the anxiety disorders, somatic arousal was specific for patients with panic disorder. Phobic fear was associated with panic disorder, simple phobia and social anxiety disorder, but not with generalized anxiety disorder. We present a five-factor model as an extension of the tripartite model. Through the addition of phobic fear, anxiety is better represented than in the tripartite model. The new scales are capable to accurately differentiate between depression and anxiety disorders, as well as between several anxiety disorders. (c) 2009 Elsevier Masson SAS. All rights reserved.

Applying Hillslope Hydrology to Bridge between Ecosystem and Grid-Scale Processes within an Earth System Model

NASA Astrophysics Data System (ADS)

Subin, Z. M.; Sulman, B. N.; Malyshev, S.; Shevliakova, E.

2013-12-01

Soil moisture is a crucial control on surface energy fluxes, vegetation properties, and soil carbon cycling. Its interactions with ecosystem processes are highly nonlinear across a large range, as both drought stress and anoxia can impede vegetation and microbial growth. Earth System Models (ESMs) generally only represent an average soil-moisture state in grid cells at scales of 50-200 km, and as a result are not able to adequately represent the effects of subgrid heterogeneity in soil moisture, especially in regions with large wetland areas. We addressed this deficiency by developing the first ESM-coupled subgrid hillslope-hydrological model, TiHy (Tiled-hillslope Hydrology), embedded within the Geophysical Fluid Dynamics Laboratory (GFDL) land model. In each grid cell, one or more representative hillslope geometries are discretized into land model tiles along an upland-to-lowland gradient. These geometries represent ~1 km hillslope-scale hydrological features and allow for flexible representation of hillslope profile and plan shapes, in addition to variation of subsurface properties among or within hillslopes. Each tile (which may represent ~100 m along the hillslope) has its own surface fluxes, vegetation state, and vertically-resolved state variables for soil physics and biogeochemistry. Resolution of water state in deep layers (~200 m) down to bedrock allows for physical integration of groundwater transport with unsaturated overlying dynamics. Multiple tiles can also co-exist at the same vertical position along the hillslope, allowing the simulation of ecosystem heterogeneity due to disturbance. The hydrological model is coupled to the vertically-resolved Carbon, Organisms, Respiration, and Protection in the Soil Environment (CORPSE) model, which captures non-linearity resulting from interactions between vertically-heterogeneous soil carbon and water profiles. We present comparisons of simulated water table depth to observations. We examine sensitivities to alternative parameterizations of hillslope geometry, macroporosity, and surface runoff / inundation, and to the choice of global topographic dataset and groundwater hydraulic conductivity distribution. Simulated groundwater dynamics among hillslopes tend to cluster into three regimes of wet and well-drained, wet but poorly-drained, and dry. In the base model configuration, near-surface gridcell-mean water tables exist in an excessively large area compared to observations, including large areas of the Eastern U.S. and Northern Europe. However, in better-drained areas, the decrease in water table depth along the hillslope gradient allows for realistic increases in ecosystem water availability and soil carbon downslope. The inclusion of subgrid hydrology can increase the equilibrium 0-2 m global soil carbon stock by a large factor, due to the nonlinear effect of anoxia. We conclude that this innovative modeling framework allows for the inclusion of hillslope-scale processes and the potential for wetland dynamics in an ESM without need for a high-resolution 3-dimensional groundwater model. Future work will include investigating the potential for future changes in land carbon fluxes caused by the effects of changing hydrological regime, particularly in peatland-rich areas poorly treated by current ESMs.

Factors Influencing Nutritional Adequacy among Rural Households in Nigeria: How Does Dietary Diversity Stand among Influencers?

PubMed

Akerele, D; Sanusi, R A; Fadare, O A; Ashaolu, O F

2017-01-01

This study examined the influence of food consumption diversity on adequate intakes of food calories, proteins and micronutrients among households in rural Nigeria within the framework of panel data econometrics using a nationally representative data. We found that substantial proportion of households suffered deficiency of calories, proteins and certain micronutrients; with higher percentage of sufferer households occurring in the post-planting season. The different measures of dietary diversity (constructed and used for analysis) consistently indicate significant and positive influence of dietary diversity on the likelihood of adequate consumption of food nutrients. While higher level of income, education and non-farm enterprise engagement may strongly stimulate adequate nutrient intakes, increases in the number of adolescents would substantially diminish it. Although our findings call for renewed attention on diet diverseness, we stress the complementary/synergistic roles of education and rural income improvement, especially through non-farm enterprise diversification in tackling multiple nutritional deficiencies in rural Nigeria.

Monitoring environmental and related performance parameters for a Rankine-cycle turbine electric generator utilizing geothermal energy at the Gila Hot Springs, New Mexico

NASA Astrophysics Data System (ADS)

Starkey, A. H.; Icerman, L.

1984-08-01

The environmental effects associated with the operation of a privately owned Rankine-cycle turbogenerator unit using low temperature geothermal resources in the form of free-flowing hot springs to produce electricity in a remote, rural area were studied. The following conclusions pertain to the operation of the turbogenerator system: (1) the heat exchanger could not provide sufficient freon vapor at the required pressures to provide adequate thermal input to the turbine; (2) conversion or redesign of the condenser and return pump to function adequately represents a problem of unknown difficulty; (3) all pressure and heat transfer tests indicated that a custom designed heat exchanger built on-site would provide adequate vapor at pressures high enough to power a 10-kW (sub e) or perhaps larger generator; and (4) automated control systems are needed for the hot and cold water supplies and the freon return pump.

Roles for the endocannabinoid system in ethanol-motivated behavior

PubMed Central

Henderson-Redmond, Angela N; Guindon, Josée; Morgan, Daniel J

2015-01-01

Alcohol use disorder represents a significant human health problem that leads to substantial loss of human life and financial cost to society. Currently available treatment options do not adequately address this human health problem, and thus, additional therapies are desperately needed. The endocannabinoid system has been shown, using animal models, to modulate ethanol-motivated behavior, and it has also been demonstrated that chronic ethanol exposure can have potentially long-lasting effects on the endocannabinoid system. For example, chronic exposure to ethanol, in either cell culture or preclinical rodent models, causes an increase in endocannabinoid levels that results in down-regulation of the cannabinoid receptor 1 (CB1) and uncoupling of this receptor from downstream G protein signaling pathways. Using positron emission tomography (PET), similar down-regulation of CB1 has been noted in multiple regions of the brain in human alcoholic patients. In rodents, treatment with the CB1 inverse agonist SR141716A (Rimonabant), or genetic deletion of CB1 leads to a reduction in voluntary ethanol drinking, ethanol-stimulated dopamine release in the nucleus accumbens, operant self-administration of ethanol, sensitization to the locomotor effects of ethanol, and reinstatement/relapse of ethanol-motivated behavior. Although the clinical utility of Rimonabant or other antagonists/inverse agonists for CB1 is limited due to negative neuropsychiatric side effects, negative allosteric modulators of CB1 and inhibitors of endocannabinoid catabolism represent therapeutic targets worthy of additional examination. PMID:26123153

Biometric and Emotion Identification: An ECG Compression Based Method.

PubMed

Brás, Susana; Ferreira, Jacqueline H T; Soares, Sandra C; Pinho, Armando J

2018-01-01

We present an innovative and robust solution to both biometric and emotion identification using the electrocardiogram (ECG). The ECG represents the electrical signal that comes from the contraction of the heart muscles, indirectly representing the flow of blood inside the heart, it is known to convey a key that allows biometric identification. Moreover, due to its relationship with the nervous system, it also varies as a function of the emotional state. The use of information-theoretic data models, associated with data compression algorithms, allowed to effectively compare ECG records and infer the person identity, as well as emotional state at the time of data collection. The proposed method does not require ECG wave delineation or alignment, which reduces preprocessing error. The method is divided into three steps: (1) conversion of the real-valued ECG record into a symbolic time-series, using a quantization process; (2) conditional compression of the symbolic representation of the ECG, using the symbolic ECG records stored in the database as reference; (3) identification of the ECG record class, using a 1-NN (nearest neighbor) classifier. We obtained over 98% of accuracy in biometric identification, whereas in emotion recognition we attained over 90%. Therefore, the method adequately identify the person, and his/her emotion. Also, the proposed method is flexible and may be adapted to different problems, by the alteration of the templates for training the model.

Biometric and Emotion Identification: An ECG Compression Based Method

PubMed Central

Brás, Susana; Ferreira, Jacqueline H. T.; Soares, Sandra C.; Pinho, Armando J.

2018-01-01

We present an innovative and robust solution to both biometric and emotion identification using the electrocardiogram (ECG). The ECG represents the electrical signal that comes from the contraction of the heart muscles, indirectly representing the flow of blood inside the heart, it is known to convey a key that allows biometric identification. Moreover, due to its relationship with the nervous system, it also varies as a function of the emotional state. The use of information-theoretic data models, associated with data compression algorithms, allowed to effectively compare ECG records and infer the person identity, as well as emotional state at the time of data collection. The proposed method does not require ECG wave delineation or alignment, which reduces preprocessing error. The method is divided into three steps: (1) conversion of the real-valued ECG record into a symbolic time-series, using a quantization process; (2) conditional compression of the symbolic representation of the ECG, using the symbolic ECG records stored in the database as reference; (3) identification of the ECG record class, using a 1-NN (nearest neighbor) classifier. We obtained over 98% of accuracy in biometric identification, whereas in emotion recognition we attained over 90%. Therefore, the method adequately identify the person, and his/her emotion. Also, the proposed method is flexible and may be adapted to different problems, by the alteration of the templates for training the model. PMID:29670564

Inferential Processing among Adequate and Struggling Adolescent Comprehenders and Relations to Reading Comprehension

PubMed Central

Barth, Amy E.; Barnes, Marcia; Francis, David J.; Vaughn, Sharon; York, Mary

2015-01-01

Separate mixed model analyses of variance (ANOVA) were conducted to examine the effect of textual distance on the accuracy and speed of text consistency judgments among adequate and struggling comprehenders across grades 6–12 (n = 1203). Multiple regressions examined whether accuracy in text consistency judgments uniquely accounted for variance in comprehension. Results suggest that there is considerable growth across the middle and high school years, particularly for adequate comprehenders in those text integration processes that maintain local coherence. Accuracy in text consistency judgments accounted for significant unique variance for passage-level, but not sentence-level comprehension, particularly for adequate comprehenders. PMID:26166946

A normal shock-wave turbulent boundary-layer interaction at transonic speeds

NASA Technical Reports Server (NTRS)

Mateer, G. G.; Brosh, A.; Viegas, J. R.

1976-01-01

Experimental results, including surveys of the mean and fluctuating flow, and measurements of surface pressure, skin friction, and separation length, are compared with solutions to the Navier-Stokes equations utilizing various algebraic eddy viscosity models to describe the Reynolds shear stresses. The experimental data, obtained at a free-stream Mach number of 1.5 and Reynolds numbers between 10 million and 80 million, show that a separated zone forms near the foot of the shock and that its length is proportional to the initial boundary-layer thickness; that a supersonic region forms downstream of the shock; and that the shear stress increases significantly through the interaction and subsequently decays downstream. The computations adequately represent the qualitative features of the flow field throughout the interaction but quantitatively underpredict the extent of separation and the downstream level of skin friction.

Removal of hexavalent chromium by biosorption process in rotating packed bed.

PubMed

Panda, M; Bhowal, A; Datta, S

2011-10-01

Removal of hexavalent chromium ions from an aqueous solution by crude tamarind (Tamarindus indica) fruit shell was examined in a rotating packed bed contactor by continuously recirculating a given volume of solution through the bed. Reduction of Cr(VI) to Cr(III) within the biosorbent appeared to be the removal mechanism. Depletion rate of Cr(VI) from, and release of reduced Cr(III) ions into the aqueous phase, was influenced by mass transfer resistance besides pH and packing depth. A mathematical model considering the reduction reaction to be irreversible and incorporating intraparticle and external phase mass transfer resistances represented the experimental data adequately. The study indicated that the limitations of fixed bed contactor operating under terrestrial gravity in intensifying mass transfer rates for this system can be overcome with rotating packed bed due to liquid flow under centrifugal acceleration.

North Atlantic Ocean OSSE system development: Nature Run evaluation and application to hurricane interaction with the Gulf Stream

NASA Astrophysics Data System (ADS)

Kourafalou, Vassiliki H.; Androulidakis, Yannis S.; Halliwell, George R.; Kang, HeeSook; Mehari, Michael M.; Le Hénaff, Matthieu; Atlas, Robert; Lumpkin, Rick

2016-11-01

A high resolution, free-running model has been developed for the hurricane region of the North Atlantic Ocean. The model is evaluated with a variety of observations to ensure that it adequately represents both the ocean climatology and variability over this region, with a focus on processes relevant to hurricane-ocean interactions. As such, it can be used as the "Nature Run" (NR) model within the framework of Observing System Simulation Experiments (OSSEs), designed specifically to improve the ocean component of coupled ocean-atmosphere hurricane forecast models. The OSSE methodology provides quantitative assessment of the impact of specific observations on the skill of forecast models and enables the comprehensive design of future observational platforms and the optimization of existing ones. Ocean OSSEs require a state-of-the-art, high-resolution free-running model simulation that represents the true ocean (the NR). This study concentrates on the development and data based evaluation of the NR model component, which leads to a reliable model simulation that has a dual purpose: (a) to provide the basis for future hurricane related OSSEs; (b) to explore process oriented studies of hurricane-ocean interactions. A specific example is presented, where the impact of Hurricane Bill (2009) on the eastward extension and transport of the Gulf Stream is analyzed. The hurricane induced cold wake is shown in both NR simulation and observations. Interaction of storm-forced currents with the Gulf Stream produced a temporary large reduction in eastward transport downstream from Cape Hatteras and had a marked influence on frontal displacement in the upper ocean. The kinetic energy due to ageostrophic currents showed a significant increase as the storm passed, and then decreased to pre-storm levels within 8 days after the hurricane advanced further north. This is a unique result of direct hurricane impact on a western boundary current, with possible implications on the ocean feedback on hurricane evolution.

[Diagnosis-related groups as an instrument to develop suitable case-based lump sums in hematology and oncology].

PubMed

Thalheimer, Markus

2011-01-01

In 2003 a new reimbursement system was established for German hospitals. The approximately 17 million inpatient cases per year are now reimbursed based on a per-case payment regarding diagnoses and procedures, which was developed from an internationally approved system. The aim was a better conformity of costs and efforts in in-patient cases. In the first 2 years after implementation, the German diagnosis-related group (DRG) system was not able to adequately represent the complex structures of treatment in hematological and oncological in-patients. By creating new diagnoses and procedures (International Classification of Diseases 10 (ICD-10) and Surgical Operations and Procedures Classification System (OPS) catalogues), generating new DRGs and better splitting of existing ones, the hematology and oncology field could be much better described in the following years. The implementation of about 70 'co-payment structures' for new and expensive drugs and procedures in oncology was also crucial. To reimburse innovations, an additional system of co-payments for innovations was established to bridge the time until innovations are represented within the DRG system itself. In summary, hematological and oncological in-patients, including cases with extraordinary costs, are meanwhile well mapped in the German reimbursement system. Any tendencies to rationing could thereby be avoided, as most of the established procedures and costly drugs are adequately represented in the DRG system. Copyright © 2011 S. Karger AG, Basel.

Investigation and simulation of dissolution with concurrent degradation under healthy and hypoalbuminaemic simulated parenteral conditions- case example Amphotericin B.

PubMed

Díaz de León-Ortega, Ricardo; D'Arcy, Deirdre M; Bolhuis, A; Fotaki, N

2018-06-01

Guidance on dissolution testing for parenteral formulations is limited and not often related in vivo performance. Critically ill patients represent a target cohort, frequently hypoalbuminaemic, to whom certain parenteral formulations are administered. Amphotericin B (AmB) is a poorly soluble, highly protein-bound drug, available as lipid-based formulations and used in critical illness. The aim of this study was to develop media representing hypoalbuminaemic and healthy plasma, and to understand and simulate the dissolution profile of AmB in biorelevant media. Dissolution media were prepared with bovine serum albumin (BSA) in Krebs-Ringer buffer, and tested in a flow through cell apparatus and a bottle/stirrer setup. Drug activity was tested against Candida albicans. BSA concentration was positively associated with solubility, degradation rate and maximum amount dissolved and negatively associated with dissolution rate constant and antifungal activity. In the bottle/stirrer setup, a biexponential model successfully described simultaneous dissolution and degradation and increased in agitation reduced the discriminatory ability of the test. The hydrodynamics provided by the flow-through cell apparatus was not adequate to dissolve the drug. Establishing discriminating test methods with albumin present in the dissolution media, representing the target population, supports future development of biorelevant and clinically relevant tests for parenteral formulations. Copyright © 2018 Elsevier B.V. All rights reserved.

Evaluation of measured and predicted environmental concentrations of selected human pharmaceuticals and personal care products.

PubMed

Liebig, Markus; Moltmann, Johann F; Knacker, Thomas

2006-03-01

In the past few years, there was an increasing awareness of the occurrence of pharmaceuticals and personal care products (PPCPs) in surface water and drinking water resources, and measurements in surface water, sediment or waste water were done for a number of PPCPs. In the regulatory context, an environmental risk assessment (ERA) has become essential for new PPCPs. Reliably predicted or measured environmental concentrations (PECs or MECs) of chemicals are essential for the exposure assessment, which is one of the two main pillars of environmental risk assessment (ERA). This paper reports on measured data of selected PPCPs in surface waters and compares the measured values with predicted environmental concentrations from exposure models. Such models have been proposed by the European Agency for the Evaluation of Medicinal Products (EMEA) and the Technical Guidance Document on Risk Assessment for New Notified and Existing Chemical Substances (TGD). Four pharmaceuticals and one personal care product were in the scope of the investigation reported here: 17alpha-ethinylestradiol, carbamazepine, sulfamethoxazole and iopromide as well as tonalide. Measured environmental concentrations in surface waters for these PPCPs were reviewed in the scientific literature. The appropriateness of these data was evaluated according to criteria for monitoring data recommended by the TGD. A total of 38 references were evaluated with emphasis on the adequacy of chemical analysis and the representativeness of sampling. Measurements of concentrations in surface water (MECsw), which were found to be adequate for use in exposure assessment according to the monitoring quality criteria, were averaged and compared with respective PECs in surface water (PECsw) derived from exposure modelling (cf. EMEA and TGD). Measured environmental concentrations adequate for use in exposure assessment were found in 20 out of 38 references. Several of the measurements from Germany could be used for a comparison with calculated PECs. Average MECs(sw) in Germany were < 0.58 ng/L for 17alpha-ethinylestradiol, 454 ng/L for carbamazepine, 126 ng/L for sulfamethoxazole, 1105 ng/L for iopromide and 311 ng/L for tonalide. In comparison to the measured concentrations, PECs calculated with the model proposed by the EMEA in 2001 were in the same range, but slightly higher than the MECs. The EMEA model from 2001 is based on a production/use volume of the PPCPs. The more recent EMEA model (2003/2005) overestimated the PECs by more than one order of magnitude for carbamazepine and sulfamethoxazole, but underestimated the concentration of 17alpha-ethinylestradiol by a factor of almost 5 compared to the MECs. This model is based on maximum daily doses and the assumption that 1% of the population is consuming the pharmaceutical (default value). Calculations with the European Union System for the Evaluation of Substances (EUSES), which is part of the TGD describing the risk assessment of chemicals and biocides, resulted for the investigated pharmaceuticals in almost the same PECs as derived by the older EMEA model (2001). For the PCP tonalide, to which the recent EMEA model (2003/ 2005) cannot be applied, the PEC was overestimated by a factor of 3 with the older EMEA model (2001), but underestimated with EUSES by a factor of 5 compared to the averaged MECsw in Germany. Conclusions. It was shown that PEC calculations with exposure models provided by EMEA and the TGD, resulted in PECs very close to the corresponding MECs in most cases. However, environmental concentrations can be underestimated by models in cases, where, e.g. due to high lipophilicity, sorption to sewage sludge is assumed which does not occur to that extent under real conditions. Thus, it appears that the exposure models do not come up to the complexity of the real environment. However, the main factor with the highest impact on predicted environmental concentrations and a high degree of uncertainty is the production volume. Recommendations and Outlook. References and their data evaluated as not adequate for use in exposure assessment were mainly rejected due to missing or insufficient specifications related to the sampling procedure and/or representativeness of the samples. Several of the evaluated studies aimed at the introduction and establishment of a new analytical methodology. A detailed description of sampling frequency and pattern, for example, was therefore neglected. Often, a more accurate description of analytical procedure, sampling pattern and statistical analysis of data would be sufficient to provide an adequate basis for exposure assessment and hence establish confidence in environmental risk assessment procedures. For new substances, an exposure assessment is solely based on estimations using environmental fate models. To avoid unacceptable risks for the environment, PECs should not underestimate actual environmental concentrations. Since it was shown that under specific conditions the models applied in this study underestimated measured environmental concentrations, further development of the calculation models appears to be necessary.

The Development and Validation of a New Land Surface Model for Regional and Global Climate Modeling

NASA Astrophysics Data System (ADS)

Lynch-Stieglitz, Marc

1995-11-01

A new land-surface scheme intended for use in mesoscale and global climate models has been developed and validated. The ground scheme consists of 6 soil layers. Diffusion and a modified tipping bucket model govern heat and water flow respectively. A 3 layer snow model has been incorporated into a modified BEST vegetation scheme. TOPMODEL equations and Digital Elevation Model data are used to generate baseflow which supports lowland saturated zones. Soil moisture heterogeneity represented by saturated lowlands subsequently impacts watershed evapotranspiration, the partitioning of surface fluxes, and the development of the storm hydrograph. Five years of meteorological and hydrological data from the Sleepers river watershed located in the eastern highlands of Vermont where winter snow cover is significant were then used to drive and validate the new scheme. Site validation data were sufficient to evaluate model performance with regard to various aspects of the watershed water balance, including snowpack growth/ablation, the spring snowmelt hydrograph, storm hydrographs, and the seasonal development of watershed evapotranspiration and soil moisture. By including topographic effects, not only are the main spring hydrographs and individual storm hydrographs adequately resolved, but the mechanisms generating runoff are consistent with current views of hydrologic processes. The seasonal movement of the mean water table depth and the saturated area of the watershed are consistent with site data and the overall model hydroclimatology, including the surface fluxes, seems reasonable.

Heating requirements and nonadiabatic surface effects for a model in the NTF (National Transonic Facility) cryogenic wind tunnel

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

Macha, J.M.; Landrum, D.B.; Pare, L.A. III

1988-01-01

A theoretical study has been made of the severity of nonadiabatic surface conditions arising from internal heat sources within a model in a cryogenic wind tunnel. Local surface heating is recognized as having an effect on the development of the boundary layer, which can introduce changes in the flow about the model and affect the wind tunnel data. The geometry was based on the NTF Pathfinder I wind tunnel model. A finite element heat transfer computer code was developed and used to compute the steady state temperature distribution within the body of the model, from which the surface temperature distributionmore » was extracted. Particular three dimensional characteristics of the model were represented with various axisymmetric approximations of the geometry. This analysis identified regions on the surface of the model susceptible to surface heating and the magnitude of the respective surface temperatures. It was found that severe surface heating may occur in particular instances, but could be alleviated with adequate insulating material. The heat flux through the surface of the model was integrated to determine the net heat required to maintain the instrumentation cavity at the prescribed temperature. The influence of the nonadiabatic condition on boundary layer properties and on the validity of the wind tunnel simulation was also investigated. 20 refs., 12 figs.« less

A new physically-based windblown dust emission ...

EPA Pesticide Factsheets

Dust has significant impacts on weather and climate, air quality and visibility, and human health; therefore, it is important to include a windblown dust emission module in atmospheric and air quality models. In this presentation, we summarize our efforts in development of a physics-based windblown dust emission scheme and its implementation in the CMAQ modeling system. The new model incorporates the effect of the surface wind speed, soil texture, soil moisture, and surface roughness in a physically sound manner. Specifically, a newly developed dynamic relation for the surface roughness length in this model is believed to adequately represent the physics of the surface processes involved in the dust generation. Furthermore, careful attention is paid in integrating the new windblown dust module within the CMAQ to ensure that the required input parameters are correctly configured. The new model is evaluated for the case studies including the continental United States and the Northern hemisphere, and is shown to be able to capture the occurrence of the dust outbreak and the level of the soil concentration. We discuss the uncertainties and limitations of the model and briefly describe our path forward for further improvements. The National Exposure Research Laboratory (NERL) Computational Exposure Division (CED) develops and evaluates data, decision-support tools, and models to be applied to media-specific or receptor-specific problem areas. CED uses modeling-based

Flight Testing an Iced Business Jet for Flight Simulation Model Validation

NASA Technical Reports Server (NTRS)

Ratvasky, Thomas P.; Barnhart, Billy P.; Lee, Sam; Cooper, Jon

2007-01-01

A flight test of a business jet aircraft with various ice accretions was performed to obtain data to validate flight simulation models developed through wind tunnel tests. Three types of ice accretions were tested: pre-activation roughness, runback shapes that form downstream of the thermal wing ice protection system, and a wing ice protection system failure shape. The high fidelity flight simulation models of this business jet aircraft were validated using a software tool called "Overdrive." Through comparisons of flight-extracted aerodynamic forces and moments to simulation-predicted forces and moments, the simulation models were successfully validated. Only minor adjustments in the simulation database were required to obtain adequate match, signifying the process used to develop the simulation models was successful. The simulation models were implemented in the NASA Ice Contamination Effects Flight Training Device (ICEFTD) to enable company pilots to evaluate flight characteristics of the simulation models. By and large, the pilots confirmed good similarities in the flight characteristics when compared to the real airplane. However, pilots noted pitch up tendencies at stall with the flaps extended that were not representative of the airplane and identified some differences in pilot forces. The elevator hinge moment model and implementation of the control forces on the ICEFTD were identified as a driver in the pitch ups and control force issues, and will be an area for future work.

Counterinsurgency and Operational Art: Is the Joint Campaign Planning Model Adequate?

DTIC Science & Technology

2003-01-01

ART: IS THE JOINT CAMAPIGN PLANNING MODEL ADEQUATE? by MAJ Thomas Erik Miller, USA, 90 pages. The United States has conducted or supported more than a...increase. Some of the effects of the fall of the Soviet Union were a loosening of internal and external political and social controls in formerly Soviet...order” in the social , economic and political arena through rapid growth in population and urbanization in the underdeveloped world, globalization and

Congenital Syphilis Masquerading as Leukemia.

PubMed

Lee, Tiffany; Bell, Stephanie; Scimeme, Jason; Maraqa, Nizar

2017-07-01

As of late, the incidence of congenital syphilis in the United States is increasing. Each new case represents a failure of preventing, diagnosing, and treating syphilis in pregnant women. Pediatricians should confirm that all women have received adequate screening for and management of syphilis during pregnancy. Congenital syphilis is easily treatable but may be a diagnostic challenge with high morbidity and mortality.

Input and SLA: Adults' Sensitivity to Different Sorts of Cues to French Gender

ERIC Educational Resources Information Center

Carroll, Susanne E.

2005-01-01

All second language (L2) learning theories presuppose that learners learn the target language from the speech signal (or written material, when learners are reading), so an understanding of learners' ability to detect and represent novel patterns in linguistic stimuli will constitute a major building block in an adequate theory of second language…

77 FR 16585 - Arkansas Midland Railroad Company, Inc.-Abandonment Exemption-in Phillips County, AK

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-21

... filed with the Board should be sent to AKMD's representative: Jeremy M. Berman, Fletcher & Sippel LLC... Surface Transportation Board (Board) or with any U.S. District Court or has been decided in favor of... this condition adequately protects affected employees, a petition for partial revocation under 49 U.S.C...

The Reliability and Validity of the Anima-Animus Continuum Scale

ERIC Educational Resources Information Center

Chow, Peter; Jeffery, Mikayla

2018-01-01

The conventional dichotomization of sex and gender into male and female has been found to be far from adequate in representing the amount of variance that exists within each biological sex. Expressions of gender and sexuality have gone beyond our imagination as more and more countries are beginning to allow a nonbinary/intersexed option on their…

40 CFR 419.13 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

...), the Regional Administrator may substitute TOC as a parameter in lieu of COD Effluent limitations for TOC shall be based on effluent data from the plant correlating TOC to BOD5. If in the judgment of the Regional Administrator, adequate correlation data are not available, the effluent limitations for TOC shall...

A Change to the Platinum Publications | Poster

Cancer.gov

Please be advised that the Poster will no longer publish the “Platinum Publications” series listing recent NCI at Frederick publications. All published research represents a valuable addition to the fight against cancer, AIDS, and infectious diseases—thus, the “Platinum Publications” did not adequately commend all of the important work done by NCI at Frederick researchers.

DETERMINING POTENTIAL RISK TO NATIVE PLANTS FROM HERBICIDE DRIFT: COMPARATIVE RESPONSE OF SELECTED CROP AND NATIVE PLANT SPECIES TO GLYPHOSATE AND SULFOMETURON

EPA Science Inventory

abstract/abstract

While native plant communities may be at risk from herbicide use, current crop-centric test procedures for pesticide registration may not adequately represent the sensitivity of native non-crop plants to herbicides. We are designing a protocol to determi...

A Case Study of the Recognition of the Foundation Degree Qualification for Pharmacy Technicians

ERIC Educational Resources Information Center

Herrera, Helena; Brown, David; Portlock, Jane

2013-01-01

The Foundation Degree (FD) is a work-related, intermediate-level higher education qualification. Issues around its recognition can affect success in attracting students where the literature suggests that uptake should be adequate. This research represented a case study which explored for the first time, whether the above applied to the FD for…

Individual and Marital Adjustment among Bereaved and Nonbereaved Parents of Children Treated for Cancer.

ERIC Educational Resources Information Center

Tucker, Cindy L.; Hansen, James C.; Zevon, Michael A.

Studies of parents of children treated for cancer have rarely included adequate samples of fathers or couples. Further, bereaved parents have been over-represented as compared to parents of cancer survivors. This study investigated the personal and interpersonal effects of having a child treated for cancer on 124 parents. Twenty-seven married…

The Federal Role in Defining "Adequate Yearly Progress": The Flexibility/Accountability Trade-Off.

ERIC Educational Resources Information Center

Goertz, Margaret E.

Bills passed by the U.S. House of Representatives and the U.S. Senate in spring 2001 to reauthorize the Elementary and Secondary Education Act (ESEA) reinforce and strengthen the education accountability provisions contained in the Improving America's Schools Act (IASA) of 1994. This paper evaluates the accountability provisions in this…

Demographic Trends and the Scientific and Engineering Work Force. A Technical Memorandum.

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. Office of Technology Assessment.

The Federal Government has acknowledged its key role in educating and assuring an adequate supply of scientists and engineers since World War II. Although scientists and engineers represent only three percent of the national work force, they are considered by many to be a crucial element in the nation's efforts to improve its economic…

Reliability and Construct Validity of Scores on the Behavioral Competence Inventory: A Measure of Adaptive Functioning.

ERIC Educational Resources Information Center

Jarjoura, David; Hartman-Stein, Paula; Speight, Joan; Reuter, Jeanette

1999-01-01

Examined the reliability and construct validity in an older adult population (n=149 older adults and their informants) of scores on the Behavioral Competence Inventory (BCI) (P. Hartman-Stein). Results indicate that scores on the BCI's seven scales show adequate internal consistencies and represent seven overlapping but distinct constructs in this…

Is There a Core in Sociology? Results from a Survey

ERIC Educational Resources Information Center

Wagenaar, Theodore C.

2004-01-01

I report on a study of 301 sociologists to determine which concepts, topics, and skills they deem most important to cover in the introductory course and in the sociology curriculum. Respondents indicated high agreement that the list of skills, topics, and concepts adequately represented the range of possible items. I use both the raw ratings and…

GCM simulations of Titan's middle and lower atmosphere and comparison to observations

NASA Astrophysics Data System (ADS)

Lora, Juan M.; Lunine, Jonathan I.; Russell, Joellen L.

2015-04-01

Simulation results are presented from a new general circulation model (GCM) of Titan, the Titan Atmospheric Model (TAM), which couples the Flexible Modeling System (FMS) spectral dynamical core to a suite of external/sub-grid-scale physics. These include a new non-gray radiative transfer module that takes advantage of recent data from Cassini-Huygens, large-scale condensation and quasi-equilibrium moist convection schemes, a surface model with "bucket" hydrology, and boundary layer turbulent diffusion. The model produces a realistic temperature structure from the surface to the lower mesosphere, including a stratopause, as well as satisfactory superrotation. The latter is shown to depend on the dynamical core's ability to build up angular momentum from surface torques. Simulated latitudinal temperature contrasts are adequate, compared to observations, and polar temperature anomalies agree with observations. In the lower atmosphere, the insolation distribution is shown to strongly impact turbulent fluxes, and surface heating is maximum at mid-latitudes. Surface liquids are unstable at mid- and low-latitudes, and quickly migrate poleward. The simulated humidity profile and distribution of surface temperatures, compared to observations, corroborate the prevalence of dry conditions at low latitudes. Polar cloud activity is well represented, though the observed mid-latitude clouds remain somewhat puzzling, and some formation alternatives are suggested.

Modeling of high-strength concrete-filled FRP tube columns under cyclic load

NASA Astrophysics Data System (ADS)

Ong, Kee-Yen; Ma, Chau-Khun; Apandi, Nazirah Mohd; Awang, Abdullah Zawawi; Omar, Wahid

2018-05-01

The behavior of high-strength concrete (HSC) - filled fiber-reinforced-polymer (FRP) tubes (HSCFFTs) column subjected to cyclic lateral loading is presented in this paper. As the experimental study is costly and time consuming, a finite element analysis (FEA) is chosen for the study. Most of the previous studies have focused on examining the axial load behavior of HSCFFT column instead of seismic behavior. The seismic behavior of HSCFFT columns has been the main interest in the industry. The key objective of this research is to develop a reliable numerical non-linear FEA model to represent the seismic behavior of such column. A FEA model was developed using the Concrete Damaged Plasticity Model (CDPM) available in the finite element software package (ABAQUS). Comparisons between experimental results from previous research and the predicted results were made based on load versus displacement relationships and ultimate strength of the column. The results showed that the column increased in ductility and able to deform to a greater extent with the increase of the FRP confinement ratio. With the increase of confinement ratio, HSCFFT column achieved a higher moment resistance, thus indicated a higher failure strength in the column under cyclic lateral load. It was found that the proposed FEA model can regenerate the experimental results with adequate accuracy.

Orientation Effects in Fault Reactivation in Geological CO2 Sequestration

NASA Astrophysics Data System (ADS)

Castelletto, N.; Ferronato, M.; Gambolati, G.; Janna, C.; Teatini, P.

2012-12-01

Geological CO2 sequestration remains one of the most promising option for reducing the greenhouse gases emission. The accurate simulation of the complex coupled physical processes occurring during the injection and the post-injection stage represents a key issue for investigating the feasibility and the safety of the sequestration. The fluid-dynamical and geochemical aspects related to sequestering CO2 underground have been widely debated in the scientific literature over more than one decade. Recently, the importance of geomechanical processes has been widely recognized. In the present modeling study, we focus on fault reactivation induced by injection, an essential aspect for the evaluation of CO2 sequestration projects that needs to be adequately investigated to avoid the generation of preferential leaking path for CO2 and the related risk of induced seismicity. We use a geomechanical model based on the structural equations of poroelasticity solved by the Finite Element (FE) - Interface Element (IE) approach. Standard FEs are used to represent a continuum, while IEs prove especially suited to assess the relative displacements of adjacent elements such as the opening and slippage of existing faults or the generation of new fractures [1]. The IEs allow for the modeling of fault mechanics using an elasto-plastic constitutive law based on the Mohr-Coulomb failure criterion. We analyze the reactivation of a single fault in a synthetic reservoir by varying the fault orientation and size, hydraulic conductivity of the faulted zone, initial vertical and horizontal stress state and Mohr-Coulomb parameters (i.e., friction angle and cohesion). References: [1] Ferronato, M., G. Gambolati, C. Janna, and P. Teatini (2008), Numerical modeling of regional faults in land subsidence prediction above gas/oil reservoirs, Int. J. Numer. Anal. Methods Geomech., 32, 633-657.

The self-aware diabetic patient software agent model.

PubMed

Wang, Zhanle; Paranjape, Raman

2013-11-01

This work presents a self-aware diabetic patient software agent for representing a human diabetic patient. To develop a 24h, stochastic and self-aware patient agent, we extend the original seminal work of Ackerman et al. [1] in creating a mathematical model of human blood glucose levels in three aspects. (1) We incorporate the stochastic and unpredictable effects of daily living. (2) The Ackerman model is extended into the period of night-time. (3) Patients' awareness of their own conditions is incorporated. Simulation results are quantitatively assessed to demonstrate the effectiveness of lifestyle management, such as adjusting the amount of food consumed, meal schedule, intensity of exercise and level of medication. In this work we show through the simulation that the average blood glucose can be reduced by as much as 51% due to careful lifestyle management. Self monitoring blood glucose is also quantitatively evaluated. The simulation results show that the average blood glucose is further dropped by 25% with the assistance of blood glucose samples. In addition, the blood glucose is perfectly controlled in the target range during the simulation period as a result of joint efforts of lifestyle management and self monitoring blood glucose. This study focuses on demonstrating how human patients' behavior, specifically lifestyle and self monitoring of blood glucose, affects blood glucose controls on a daily basis. This work does not focus on the insulin-glucose interaction of an individual human patient. Our conclusion is that this self-aware patient agent model is capable of adequately representing diabetic patients and of evaluating their dynamic behaviors. It can also be incorporated into a multi-agent system by introducing other healthcare components so that more interesting insights such as the healthcare quality, cost and performance can be observed. © 2013 Published by Elsevier Ltd.

CONSTELL: NASA's Satellite Constellation Model

NASA Technical Reports Server (NTRS)

Theall, Jeffrey R.; Krisko, Paula H.; Opiela, John N.; McKay, Gordon A. (Technical Monitor)

1999-01-01

The CONSTELL program represents an initial effort by the orbital debris modeling group at NASA/JSC to address the particular issues and problems raised by the presence of LEO satellite constellations. It was designed to help NASA better understand the potential orbital debris consequences of having satellite constellations operating in the future in LEO. However, it could also be used by constellation planners to evaluate architecture or design alternatives that might lessen debris consequences for their constellation or lessen the debris effects on other users of space. CONSTELL is designed to perform debris environment projections rapidly so it can support parametric assessments involving either the constellations themselves or the background environment which represents non-constellation users of the space. The projections need to be calculated quickly because a number of projections are often required to adequately span the parameter space of interest. To this end CONSTELL uses the outputs of other NASA debris environment models as inputs, thus doing away with the need for time consuming upfront calculations. Specifically, CONSTELL uses EVOLVE or ORDEM96 debris spatial density results as its background environment, debris cloud snapshot templates to simulate debris cloud propagation, and time dependent orbit profiles of the intact non- functional constellation spacecraft and upper stages. In this paper the environmental consequences of the deployment of particular LEO satellite constellations using the CONSTELL model will be evaluated. Constellations that will undergo a parametric assessment will reflect realistic parameter values. Among other results the increase in loss rate of non-constellation spacecraft, the number of collisions involving constellation elements, and the replacement rate of constellation satellites as a result of debris impact will be presented.

Abiotic/biotic coupling in the rhizosphere: a reactive transport modeling analysis

USGS Publications Warehouse

Lawrence, Corey R.; Steefel, Carl; Maher, Kate

2014-01-01

A new generation of models is needed to adequately simulate patterns of soil biogeochemical cycling in response changing global environmental drivers. For example, predicting the influence of climate change on soil organic matter storage and stability requires models capable of addressing complex biotic/abiotic interactions of rhizosphere and weathering processes. Reactive transport modeling provides a powerful framework simulating these interactions and the resulting influence on soil physical and chemical characteristics. Incorporation of organic reactions in an existing reactive transport model framework has yielded novel insights into soil weathering and development but much more work is required to adequately capture root and microbial dynamics in the rhizosphere. This endeavor provides many advantages over traditional soil biogeochemical models but also many challenges.

Uncertainty in flood forecasting: A distributed modeling approach in a sparse data catchment

NASA Astrophysics Data System (ADS)

Mendoza, Pablo A.; McPhee, James; Vargas, Ximena

2012-09-01

Data scarcity has traditionally precluded the application of advanced hydrologic techniques in developing countries. In this paper, we evaluate the performance of a flood forecasting scheme in a sparsely monitored catchment based on distributed hydrologic modeling, discharge assimilation, and numerical weather predictions with explicit validation uncertainty analysis. For the hydrologic component of our framework, we apply TopNet to the Cautin River basin, located in southern Chile, using a fully distributed a priori parameterization based on both literature-suggested values and data gathered during field campaigns. Results obtained from this step indicate that the incremental effort spent in measuring directly a set of model parameters was insufficient to represent adequately the most relevant hydrologic processes related to spatiotemporal runoff patterns. Subsequent uncertainty validation performed over a six month ensemble simulation shows that streamflow uncertainty is better represented during flood events, due to both the increase of state perturbation introduced by rainfall and the flood-oriented calibration strategy adopted here. Results from different assimilation configurations suggest that the upper part of the basin is the major source of uncertainty in hydrologic process representation and hint at the usefulness of interpreting assimilation results in terms of model input and parameterization inadequacy. Furthermore, in this case study the violation of Markovian state properties by the Ensemble Kalman filter did affect the numerical results, showing that an explicit treatment of the time delay between the generation of surface runoff and the arrival at the basin outlet is required in the assimilation scheme. Peak flow forecasting results demonstrate that there is a major problem with the Weather Research and Forecasting model outputs, which systematically overestimate precipitation over the catchment. A final analysis performed for a large flooding event that occurred in July 2006 shows that, in the absence of bias introduced by an incorrect model calibration, the updating of both model states and meteorological forecasts contributes to a better representation of streamflow uncertainty and to better hydrologic forecasts.

Molecular tracing of confiscated pangolin scales for conservation and illegal trade monitoring in Southeast Asia

USGS Publications Warehouse

Zhang, Huarong; Miller, Mark P.; Yang, Feng; Chan, Hon Ki; Gaubert, Philippe; Ades, Gary; Fischer, Gunter A

2015-01-01

Despite being protected by both international and national regulations, pangolins are threatened by illegal trade. Here we report mitochondrial DNA identification and haplotype richness estimation, using 239 pangolin scale samples from two confiscations in Hong Kong. We found a total of 13 genetically distinct cytochrome c oxidase I (COI) haplotypes in two confiscations (13 and ten haplotypes respectively, with ten shared haplotypes between confiscations). These haplotypes clustered in two distinct clades with one clade representing the Sunda pangolin (Manisjavanica). The other clade did not match with any known Asian pangolin sequences, and likely represented a cryptic pangolin lineage in Asia. By fitting sample coverage and rarefaction/regression models to our sample data, we predicted that the total number of COI haplotypes in two confiscations were 14.86 and 11.06 respectively, suggesting that our sampling caught the majority of haplotypes and that we had adequately characterized each confiscation. We detected substantial sequence divergence among the seized scales, likely evidencing that the Sunda pangolins were harvested over wide geographical areas across Southeast Asia. Our study illustrates the value of applying DNA forensics for illegal wildlife trade monitoring.

Psychometric properties of the Spanish version of the Controlling Coach Behaviors Scale in the sport context.

PubMed

Castillo, Isabel; Tomás, Inés; Ntoumanis, Nikos; Bartholomew, Kimberley; Duda, Joan L; Balaguer, Isabel

2014-01-01

The purpose of this research was to translate into Spanish and examine the psychometric properties of the Spanish version of the Controlling Coach Behaviors Scale (CCBS) in male soccer players. The CCBS is a questionnaire designed to assess athletes' perceptions of sports coaches' controlling interpersonal style from the perspective of the self-determination theory. Study 1 tested the factorial structure of the translated scale using confirmatory factor analysis (CFA) and provided evidence of discriminant validity. Studies 2 and 3 examined the invariance across time and across competitive level via multi-sample CFA. Reliability analyses were also conducted. The CFA results revealed that a four-factor model was acceptable, indicating that a controlling interpersonal style is a multidimensional construct represented by four separate and related controlling coaching strategies. Further, results supported the invariance of the CCBS factor structure across time and competitive level and provided support for the internal consistency of the scale. Overall, the CCBS demonstrated adequate internal consistency, as well as good factorial validity. The Spanish version of the CCBS represents a valid and reliable adaptation of the instrument, which can be confidently used to measure soccer players' perceptions of their coaches' controlling interpersonal style.

There’s Something About Molly: The Under-Researched yet Popular Powder Form of Ecstasy in the United States

PubMed Central

Palamar, Joseph J.

2017-01-01

Molly has been the street name for powder or crystalline ecstasy (3,4-methylenedioxymethamphetamine [MDMA]) in the United States since at least 2008; however, few studies have examined Molly use or included Molly in the definition of ecstasy/MDMA. Prevalence of self-reported ecstasy use is being underreported on surveys due to the lack of inclusion of “Molly”, although Molly is often so adulterated with novel psychoactive substances such as synthetic cathinones (“bath salts”) that the name “Molly” may no longer adequately represent ecstasy/MDMA. The author recommends that Molly use and Molly purity be further studied to more adequately inform prevention and harm reduction. PMID:27925866

Social marketing: an approach to planned social change.

PubMed

Kotler, P; Zaltman, G

1971-07-01

This article examines the applicability of marketing concepts to social causes and social change. Social marketing is defined as the design, implementation, and control of programs calculated to influence the acceptability of social ideas and involving considerations of product planning, pricing, communication, distribution and marketing research. Wiebe examined four social advertising campaigns and concluded that their effectiveness depended on the presence of adequate force, direction, adequate and compatible social mechanism, and distance (the "cost" of the new attitude as seen by message's message"s recepient). A marketing planning approach is not a guarantee for the achievement of social objectives; yet, it represents a bridging mechanism linking the knowledge of the behavioral scientist with the socially useful implementation of that knowledge.

Quantification of soil mapping by digital analysis of LANDSAT data. [Clinton County, Indiana

NASA Technical Reports Server (NTRS)

Kirschner, F. R.; Kaminsky, S. A.; Hinzel, E. J.; Sinclair, H. R.; Weismiller, R. A.

1977-01-01

Soil survey mapping units are designed such that the dominant soil represents the major proportion of the unit. At times, soil mapping delineations do not adequately represent conditions as stated in the mapping unit descriptions. Digital analysis of LANDSAT multispectral scanner (MSS) data provides a means of accurately describing and quantifying soil mapping unit composition. Digital analysis of LANDSAT MSS data collected on 9 June 1973 was used to prepare a spectral soil map for a 430-hectare area in Clinton County, Indiana. Fifteen spectral classes were defined, representing 12 soil and 3 vegetation classes. The 12 soil classes were grouped into 4 moisture regimes based upon their spectral responses; the 3 vegetation classes were grouped into one all-inclusive class.

Effectiveness of the Treatment Readiness and Induction Program for increasing adolescent motivation for change.

PubMed

Becan, Jennifer E; Knight, Danica K; Crawley, Rachel D; Joe, George W; Flynn, Patrick M

2015-03-01

Success in substance abuse treatment is improved by problem recognition, desire to seek help, and readiness to engage in treatment, all of which are important aspects of motivation. Interventions that facilitate these at treatment induction for adolescents are especially needed. The purpose of this study is to assess the effectiveness of TRIP (Treatment Readiness and Induction Program) in promoting treatment motivation. Data represent 519 adolescents from 6 residential programs who completed assessments at treatment intake (time 1) and 35 days after admission (time 2). The design consisted of a comparison sample (n=281) that had enrolled in treatment prior to implementation of TRIP (standard operating practice) and a sample of clients that had entered treatment after TRIP began and received standard operating practice enhanced by TRIP (n=238). Repeated measures ANCOVAs were conducted using each time 2 motivation scale as a dependent measure. Motivation scales were conceptualized as representing sequential stages of change. LISREL was used to test a structural model involving TRIP participation, gender, drug use severity, juvenile justice involvement, age, race-ethnicity, prior treatment, and urgency as predictors of the stages of treatment motivation. Compared to standard practice, adolescents receiving TRIP demonstrated greater gains in problem recognition, even after controlling for the other variables in the model. The model fit was adequate, with TRIP directly affecting problem recognition and indirectly affecting later stages of change (desire for help and treatment readiness). Future studies should examine which specific components of TRIP affect change in motivation. Copyright © 2015 Elsevier Inc. All rights reserved.

Sequencing the transcriptome of milk production: milk trumps mammary tissue

PubMed Central

2013-01-01

Background Studies of normal human mammary gland development and function have mostly relied on cell culture, limited surgical specimens, and rodent models. Although RNA extracted from human milk has been used to assay the mammary transcriptome non-invasively, this assay has not been adequately validated in primates. Thus, the objectives of the current study were to assess the suitability of lactating rhesus macaques as a model for lactating humans and to determine whether RNA extracted from milk fractions is representative of RNA extracted from mammary tissue for the purpose of studying the transcriptome of milk-producing cells. Results We confirmed that macaque milk contains cytoplasmic crescents and that ample high-quality RNA can be obtained for sequencing. Using RNA sequencing, RNA extracted from macaque milk fat and milk cell fractions more accurately represented RNA from mammary epithelial cells (cells that produce milk) than did RNA from whole mammary tissue. Mammary epithelium-specific transcripts were more abundant in macaque milk fat, whereas adipose or stroma-specific transcripts were more abundant in mammary tissue. Functional analyses confirmed the validity of milk as a source of RNA from milk-producing mammary epithelial cells. Conclusions RNA extracted from the milk fat during lactation accurately portrayed the RNA profile of milk-producing mammary epithelial cells in a non-human primate. However, this sample type clearly requires protocols that minimize RNA degradation. Overall, we validated the use of RNA extracted from human and macaque milk and provided evidence to support the use of lactating macaques as a model for human lactation. PMID:24330573

Knowledge and attitudes of nurses on pressure ulcer prevention: a cross-sectional multicenter study in Belgian hospitals.

PubMed

Beeckman, Dimitri; Defloor, Tom; Schoonhoven, Lisette; Vanderwee, Katrien

2011-09-01

Evidence-based guidelines for pressure ulcer prevention have been developed and promoted by authoritative organizations. However, nonadherence to these guidelines is frequently reported. Negative attitudes and lack of knowledge may act as barriers to using guidelines in clinical practice. To study the knowledge and attitudes of nurses about pressure ulcer prevention in Belgian hospitals and to explore the correlation between knowledge, attitudes, and the application of adequate prevention. A cross-sectional multicenter study was performed in a random sample of 14 Belgian hospitals, representing 207 wards. Out of that group, 94 wards were randomly selected (2105 patients). Clinical observations were performed to assess the adequacy of pressure ulcer prevention and pressure ulcer prevalence. From each participating ward, a random selection of at least five nurses completed an extensively validated knowledge and attitude instrument. In total, 553 nurses participated. A logistic regression analysis was performed to evaluate the correlation between knowledge, attitudes, and the application of adequate prevention. Pressure ulcer prevalence (Category I-IV) was 13.5% (284/2105). Approximately 30% (625/2105) of the patients were at risk (Bradenscore <17 and/or presence of pressure ulcer). Only 13.9% (87/625) of these patients received fully adequate prevention whilst in bed and when seated. The mean knowledge and attitude scores were 49.7% and 71.3%, respectively. The application of adequate prevention on a nursing ward was significantly correlated with the attitudes of the nurses (OR = 3.07, p = .05). No independent correlation was found between knowledge and the application of adequate prevention (OR = 0.75, p = .71). Knowledge of nurses in Belgian hospitals about the prevention of pressure ulcers is inadequate. The attitudes of nurses toward pressure ulcers are significantly correlated with the application of adequate prevention. No correlation was found between knowledge and the application of adequate prevention. Copyright ©2011 Sigma Theta Tau International.

Correlates of women's knowledge of mother-to-child transmission of HIV and its prevention in Tanzania: a population-based study.

PubMed

Haile, Zelalem T; Teweldeberhan, Asli K; Chertok, Ilana R A

2016-01-01

Studies that explored women's knowledge on mother-to-child transmission (MTCT) of HIV and its prevention (PMTCT) in the general population are currently lacking. This paper examined factors associated with having adequate knowledge of MTCT of HIV and PMTCT among a nationally representative sample of women in Tanzania. We conducted a cross-sectional analysis including 10,299 women from the 2011-2012 Tanzania HIV/AIDS and Malaria Indicator Survey. The outcome of interest was the presence of adequate knowledge on MTCT and PMTCT of HIV. We used multivariable logistic regression to identify factors associated with having adequate knowledge on MTCT and PMTCT of HIV. Results revealed that the overall prevalence of having adequate knowledge on MTCT and PMTCT of HIV was low (46%). We found a statistically significant difference in the proportions of having adequate knowledge between HIV-negative and HIV-positive women (45% vs. 56%; p < .0001), although knowledge of the transplacental route of transmission did not differ by HIV serostatus. Overall, having adequate knowledge on MTCT and PMTCT of HIV was positively associated with experiencing at least one pregnancy, having some education, having higher household wealth, residing in urban area, being exposed to HIV education, having tested for HIV, knowing a place to get HIV test, and having comprehensive knowledge on HIV and AIDS. Among HIV-seropositive women, experiencing at least one pregnancy and having comprehensive knowledge on HIV and AIDS were strongly associated with having adequate knowledge on MTCT and PMTCT of HIV (Adjusted odds ratio: aOR 2.78, 95% CI 1.21, 6.37 and aOR 1.71, 95% CI 1.15, 2.73, respectively). Further efforts are needed to enhance HIV/AIDS education among women of childbearing age and strengthen PMTCT services in Tanzania.

Federal and Provincial Responsibilities to Implement Physician-Assisted Suicide.

PubMed

Baker, David; Sharpe, Gilbert; Lauks, Rebeka

2016-02-01

In the most significant constitutional decision of the last generation, Carter v. Canada, the Supreme Court of Canada reversed itself and decided that it was possible for Parliament to enact safeguards that would be adequate to protect persons who are vulnerable in times of weakness, then proceeded to declare that Canadians were entitled to a s. 7 Charter right to physician-assisted death. David Baker and Gilbert Sharpe accepted the challenge issued by the Court and drafted a Bill to amend the Criminal Code in a manner they believed would strike a constitutional balance between providing access to the right declared by the Court and protecting the vulnerable. This article represents their attempt, along with co-author Rebeka Lauks, to explain many of the key provisions in their draft. Amongst the most noteworthy are their attempts to ensure that those choosing PAD are informed about quality of life, as well as treatment choices; to define vulnerability and to install safeguards adequate to protect persons while vulnerable; and finally a prior review process that would ensure both ready access to the Charter right declared by the Court and consistent and transparent application of the law. The authors have attempted to establish an alternative model to that currently in effect in the Benelux countries, which they regard as having been ineffective in achieving any of these objectives.

Informing Estimates of Program Effects for Studies of Mathematics Professional Development Using Teacher Content Knowledge Outcomes.

PubMed

Phelps, Geoffrey; Kelcey, Benjamin; Jones, Nathan; Liu, Shuangshuang

2016-10-03

Mathematics professional development is widely offered, typically with the goal of improving teachers' content knowledge, the quality of teaching, and ultimately students' achievement. Recently, new assessments focused on mathematical knowledge for teaching (MKT) have been developed to assist in the evaluation and improvement of mathematics professional development. This study presents empirical estimates of average program change in MKT and its variation with the goal of supporting the design of experimental trials that are adequately powered to detect a specified program effect. The study drew on a large database representing five different assessments of MKT and collectively 326 professional development programs and 9,365 teachers. Results from cross-classified hierarchical growth models found that standardized average change estimates across the five assessments ranged from a low of 0.16 standard deviations (SDs) to a high of 0.26 SDs. Power analyses using the estimated pre- and posttest change estimates indicated that hundreds of teachers are needed to detect changes in knowledge at the lower end of the distribution. Even studies powered to detect effects at the higher end of the distribution will require substantial resources to conduct rigorous experimental trials. Empirical benchmarks that describe average program change and its variation provide a useful preliminary resource for interpreting the relative magnitude of effect sizes associated with professional development programs and for designing adequately powered trials. © The Author(s) 2016.

12 CFR Appendix A to Part 1720 - Policy Guidance; Minimum Safety and Soundness Requirements

Code of Federal Regulations, 2011 CFR

2011-01-01

... effectively and to model the effect of differing interest rate scenarios on the Enterprise's financial... liquidity under varying scenarios. IV. Information technology. An Enterprise should establish and implement... functions; iv. Adequate testing and review of audited areas together with adequate documentation of findings...

PDS Work at a Small University: Solutions to Common Problems

ERIC Educational Resources Information Center

Mills, Lynne

2010-01-01

Small universities deal with two primary issues when beginning to use the Professional Development School model: Adequate Funding and Faculty Support. Possible solutions are discussed, including ways to provide adequate funding through grants, enrichment/tutoring programs, reallocation of existing funds, and university priority money, as well as…

76 FR 9982 - Airworthiness Directives; Bombardier, Inc. Model DHC-8-400 Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-23

... manufactured with an outlet fitting containing red anodized threads. These MFCV do not provide adequate... that some motive flow check valves (MFCV) were manufactured with an outlet fitting containing red... containing red anodized threads. These MFCV do not provide adequate electrical bonding between the valve and...

Fold assessment for comparative protein structure modeling.

PubMed

Melo, Francisco; Sali, Andrej

2007-11-01

Accurate and automated assessment of both geometrical errors and incompleteness of comparative protein structure models is necessary for an adequate use of the models. Here, we describe a composite score for discriminating between models with the correct and incorrect fold. To find an accurate composite score, we designed and applied a genetic algorithm method that searched for a most informative subset of 21 input model features as well as their optimized nonlinear transformation into the composite score. The 21 input features included various statistical potential scores, stereochemistry quality descriptors, sequence alignment scores, geometrical descriptors, and measures of protein packing. The optimized composite score was found to depend on (1) a statistical potential z-score for residue accessibilities and distances, (2) model compactness, and (3) percentage sequence identity of the alignment used to build the model. The accuracy of the composite score was compared with the accuracy of assessment by single and combined features as well as by other commonly used assessment methods. The testing set was representative of models produced by automated comparative modeling on a genomic scale. The composite score performed better than any other tested score in terms of the maximum correct classification rate (i.e., 3.3% false positives and 2.5% false negatives) as well as the sensitivity and specificity across the whole range of thresholds. The composite score was implemented in our program MODELLER-8 and was used to assess models in the MODBASE database that contains comparative models for domains in approximately 1.3 million protein sequences.

Conceptual modelling of E. coli in urban stormwater drains, creeks and rivers

NASA Astrophysics Data System (ADS)

Jovanovic, Dusan; Hathaway, Jon; Coleman, Rhys; Deletic, Ana; McCarthy, David T.

2017-12-01

Accurate estimation of faecal microorganism levels in water systems, such as stormwater drains, creeks and rivers, is needed for appropriate assessment of impacts on receiving water bodies and the risks to human health. The underlying hypothesis for this work is that a single conceptual model (the MicroOrganism Prediction in Urban Stormwater model - i.e. MOPUS) can adequately simulate microbial dynamics over a variety of water systems and wide range of scales; something which has not been previously tested. Additionally, the application of radar precipitation data for improvement of the model performance at these scales via more accurate areal averaged rainfall intensities was tested. Six comprehensive Escherichia coli (E. coli) datasets collected from five catchments in south-eastern Australia and one catchment in Raleigh, USA, were used to calibrate the model. The MOPUS rainfall-runoff model performed well at all scales (Nash-Sutcliffe E for instantaneous flow rates between 0.70 and 0.93). Sensitivity analysis showed that wet weather urban stormwater flows can be modelled with only three of the five rainfall runoff model parameters: routing coefficient (K), effective imperviousness (IMP) and time of concentration (TOC). The model's performance for representing instantaneous E. coli fluctuations ranged from 0.17 to 0.45 in catchments drained via pipe or open creek, and was the highest for a large riverine catchment (0.64); performing similarly, if not better, than other microbial models in literature. The model could also capture the variability in event mean concentrations (E = 0.17-0.57) and event loads (E = 0.32-0.97) at all scales. Application of weather radar-derived rainfall inputs caused lower overall performance compared to using gauged rainfall inputs in representing both flow and E. coli levels in urban drain catchments, with the performance improving with increasing catchment size and being comparable to the models that use gauged rainfall inputs at the large riverine catchment. These results demonstrate the potential of the MOPUS model and its ability to be applied to a wide range of catchment scales, including large riverine systems.

A response surface methodology based damage identification technique

NASA Astrophysics Data System (ADS)

Fang, S. E.; Perera, R.

2009-06-01

Response surface methodology (RSM) is a combination of statistical and mathematical techniques to represent the relationship between the inputs and outputs of a physical system by explicit functions. This methodology has been widely employed in many applications such as design optimization, response prediction and model validation. But so far the literature related to its application in structural damage identification (SDI) is scarce. Therefore this study attempts to present a systematic SDI procedure comprising four sequential steps of feature selection, parameter screening, primary response surface (RS) modeling and updating, and reference-state RS modeling with SDI realization using the factorial design (FD) and the central composite design (CCD). The last two steps imply the implementation of inverse problems by model updating in which the RS models substitute the FE models. The proposed method was verified against a numerical beam, a tested reinforced concrete (RC) frame and an experimental full-scale bridge with the modal frequency being the output responses. It was found that the proposed RSM-based method performs well in predicting the damage of both numerical and experimental structures having single and multiple damage scenarios. The screening capacity of the FD can provide quantitative estimation of the significance levels of updating parameters. Meanwhile, the second-order polynomial model established by the CCD provides adequate accuracy in expressing the dynamic behavior of a physical system.

Modelling bidirectional fluxes of methanol and acetaldehyde with the FORCAsT canopy exchange model

DOE PAGES

Ashworth, Kirsti; Chung, Serena H.; McKinney, Karena A.; ...

2016-12-15

Here, the FORCAsT canopy exchange model was used to investigate the underlying mechanisms governing foliage emissions of methanol and acetaldehyde, two short chain oxygenated volatile organic compounds ubiquitous in the troposphere and known to have strong biogenic sources, at a northern mid-latitude forest site. The explicit representation of the vegetation canopy within the model allowed us to test the hypothesis that stomatal conductance regulates emissions of these compounds to an extent that its influence is observable at the ecosystem scale, a process not currently considered in regional- or global-scale atmospheric chemistry models. Here, we found that FORCAsT could only reproducemore » the magnitude and diurnal profiles of methanol and acetaldehyde fluxes measured at the top of the forest canopy at Harvard Forest if light-dependent emissions were introduced to the model. With the inclusion of such emissions, FORCAsT was able to successfully simulate the observed bidirectional exchange of methanol and acetaldehyde. Although we found evidence that stomatal conductance influences methanol fluxes and concentrations at scales beyond the leaf level, particularly at dawn and dusk, we were able to adequately capture ecosystem exchange without the addition of stomatal control to the standard parameterisations of foliage emissions, suggesting that ecosystem fluxes can be well enough represented by the emissions models currently used.« less

A spatial simulation model of hydrology and vegetation dynamics in semi-permanent prairie wetlands

USGS Publications Warehouse

Poiani, Karen A.; Johnson, W. Carter

1993-01-01

The objective of this study was to construct a spatial simulation model of the vegetation dynamics in semi-permanent prairie wetlands. A hydrologic submodel estimated water levels based on precipitation, runoff, and potential evapotranspiration. A vegetation submodel calculated the amount and distribution of emergent cover and open water using a geographic information system. The response of vegetation to water-level changes was based on seed bank composition, seedling recruitment and establishment, and plant survivorship. The model was developed and tested using data from the Cottonwood Lake study site in North Dakota. Data from semi-permanent wetland P1 were used to calibrate the model. Data from a second wetland, P4, were used to evaluate model performance. Simulation results were compared with actual water data from 1797 through 1989. Test results showed that differences between calculated and observed water levels were within 10 cm 75% of the time. Open water over the past decade ranged from 0 to 7% in wetland P4 and from 0 to 8% in submodel simulations. Several model parameters including evapotranspiration and timing of seedling germination could be improved with more complex techniques or relatively minor adjustments. Despite these differences the model adequately represented vegetation dynamics of prairie wetlands and can be used to examine wetland response to natural or human-induced climate change.

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).