Science.gov

Sample records for formation predictability maps

  1. RESIDUA UPGRADING EFFICIENCY IMPROVEMENT MODELS: COKE FORMATION PREDICTABILITY MAPS

    SciTech Connect

    John F. Schabron; A. Troy Pauli; Joseph F. Rovani Jr.

    2002-05-01

    The dispersed particle solution model of petroleum residua structure was used to develop predictors for pyrolytic coke formation. Coking Indexes were developed in prior years that measure how near a pyrolysis system is to coke formation during the coke formation induction period. These have been demonstrated to be universally applicable for residua regardless of the source of the material. Coking onset is coincidental with the destruction of the ordered structure and the formation of a multiphase system. The amount of coke initially formed appears to be a function of the free solvent volume of the original residua. In the current work, three-dimensional coke make predictability maps were developed at 400 C, 450 C, and 500 C (752 F, 842 F, and 932 F). These relate residence time and free solvent volume to the amount of coke formed at a particular pyrolysis temperature. Activation energies for two apparent types of zero-order coke formation reactions were estimated. The results provide a new tool for ranking residua, gauging proximity to coke formation, and predicting initial coke make tendencies.

  2. Compressor map prediction tool

    NASA Astrophysics Data System (ADS)

    Ravi, Arjun; Sznajder, Lukasz; Bennett, Ian

    2015-08-01

    Shell Global Solutions uses an in-house developed system for remote condition monitoring of centrifugal compressors. It requires field process data collected during operation to calculate and assess the machine's performance. Performance is assessed by comparing live results of polytropic head and efficiency versus design compressor curves provided by the Manufacturer. Typically, these design curves are given for specific suction conditions. The further these conditions on site deviate from those prescribed at design, the less accurate the health assessment of the compressor becomes. To address this specified problem, a compressor map prediction tool is proposed. The original performance curves of polytropic head against volumetric flow for varying rotational speeds are used as an input to define a range of Mach numbers within which the non-dimensional invariant performance curve of head and volume flow coefficient is generated. The new performance curves of polytropic head vs. flow for desired set of inlet conditions are then back calculated using the invariant non-dimensional curve. Within the range of Mach numbers calculated from design data, the proposed methodology can predict polytropic head curves at a new set of inlet conditions within an estimated 3% accuracy. The presented methodology does not require knowledge of detailed impeller geometry such as throat areas, blade number, blade angles, thicknesses nor other aspects of the aerodynamic design - diffusion levels, flow angles, etc. The only required mechanical design feature is the first impeller tip diameter. Described method makes centrifugal compressor surveillance activities more accurate, enabling precise problem isolation affecting machine's performance.

  3. Star Formation for Predictive Primordial Galaxy Formation

    NASA Astrophysics Data System (ADS)

    Milosavljević, Miloš; Safranek-Shrader, Chalence

    The elegance of inflationary cosmology and cosmological perturbation theory ends with the formation of the first stars and galaxies, the initial sources of light that launched the phenomenologically rich process of cosmic reionization. Here we review the current understanding of early star formation, emphasizing unsolved problems and technical challenges. We begin with the first generation of stars to form after the Big Bang and trace how they influenced subsequent star formation. The onset of chemical enrichment coincided with a sharp increase in the overall physical complexity of star forming systems. Ab-initio computational treatments are just now entering the domain of the predictive and are establishing contact with local observations of the relics of this ancient epoch.

  4. Spatial predictive mapping using artificial neural networks

    NASA Astrophysics Data System (ADS)

    Noack, S.; Knobloch, A.; Etzold, S. H.; Barth, A.; Kallmeier, E.

    2014-11-01

    The modelling or prediction of complex geospatial phenomena (like formation of geo-hazards) is one of the most important tasks for geoscientists. But in practice it faces various difficulties, caused mainly by the complexity of relationships between the phenomena itself and the controlling parameters, as well by limitations of our knowledge about the nature of physical/ mathematical relationships and by restrictions regarding accuracy and availability of data. In this situation methods of artificial intelligence, like artificial neural networks (ANN) offer a meaningful alternative modelling approach compared to the exact mathematical modelling. In the past, the application of ANN technologies in geosciences was primarily limited due to difficulties to integrate it into geo-data processing algorithms. In consideration of this background, the software advangeo® was developed to provide a normal GIS user with a powerful tool to use ANNs for prediction mapping and data preparation within his standard ESRI ArcGIS environment. In many case studies, such as land use planning, geo-hazards analysis and prevention, mineral potential mapping, agriculture & forestry advangeo® has shown its capabilities and strengths. The approach is able to add considerable value to existing data.

  5. Crop Biometric Maps: The Key to Prediction

    PubMed Central

    Rovira-Más, Francisco; Sáiz-Rubio, Verónica

    2013-01-01

    The sustainability of agricultural production in the twenty-first century, both in industrialized and developing countries, benefits from the integration of farm management with information technology such that individual plants, rows, or subfields may be endowed with a singular “identity.” This approach approximates the nature of agricultural processes to the engineering of industrial processes. In order to cope with the vast variability of nature and the uncertainties of agricultural production, the concept of crop biometrics is defined as the scientific analysis of agricultural observations confined to spaces of reduced dimensions and known position with the purpose of building prediction models. This article develops the idea of crop biometrics by setting its principles, discussing the selection and quantization of biometric traits, and analyzing the mathematical relationships among measured and predicted traits. Crop biometric maps were applied to the case of a wine-production vineyard, in which vegetation amount, relative altitude in the field, soil compaction, berry size, grape yield, juice pH, and grape sugar content were selected as biometric traits. The enological potential of grapes was assessed with a quality-index map defined as a combination of titratable acidity, sugar content, and must pH. Prediction models for yield and quality were developed for high and low resolution maps, showing the great potential of crop biometric maps as a strategic tool for vineyard growers as well as for crop managers in general, due to the wide versatility of the methodology proposed. PMID:24064605

  6. Crop biometric maps: the key to prediction.

    PubMed

    Rovira-Más, Francisco; Sáiz-Rubio, Verónica

    2013-01-01

    The sustainability of agricultural production in the twenty-first century, both in industrialized and developing countries, benefits from the integration of farm management with information technology such that individual plants, rows, or subfields may be endowed with a singular "identity." This approach approximates the nature of agricultural processes to the engineering of industrial processes. In order to cope with the vast variability of nature and the uncertainties of agricultural production, the concept of crop biometrics is defined as the scientific analysis of agricultural observations confined to spaces of reduced dimensions and known position with the purpose of building prediction models. This article develops the idea of crop biometrics by setting its principles, discussing the selection and quantization of biometric traits, and analyzing the mathematical relationships among measured and predicted traits. Crop biometric maps were applied to the case of a wine-production vineyard, in which vegetation amount, relative altitude in the field, soil compaction, berry size, grape yield, juice pH, and grape sugar content were selected as biometric traits. The enological potential of grapes was assessed with a quality-index map defined as a combination of titratable acidity, sugar content, and must pH. Prediction models for yield and quality were developed for high and low resolution maps, showing the great potential of crop biometric maps as a strategic tool for vineyard growers as well as for crop managers in general, due to the wide versatility of the methodology proposed. PMID:24064605

  7. Preparation and Presentation of Digital Maps in Raster Format

    USGS Publications Warehouse

    Edwards, K.; Batson, R.M.

    1980-01-01

    A set of algorithms has been developed at USGS Flagstaff for displaying digital map data in raster format. The set includes: FILLIN, which assigns a specified attribute code to units of a map which have been outlined on a digitizer and converted to raster format; FILBND, which removes the outlines; ZIP, which adds patterns to the map units; and COLOR, which provides a simplified process for creating color separation plates for either photographic or lithographic reproduction. - Authors

  8. Accuracy, resolution, and cost comparisons between small format and mapping cameras for environmental mapping

    NASA Technical Reports Server (NTRS)

    Clegg, R. H.; Scherz, J. P.

    1975-01-01

    Successful aerial photography depends on aerial cameras providing acceptable photographs within cost restrictions of the job. For topographic mapping where ultimate accuracy is required only large format mapping cameras will suffice. For mapping environmental patterns of vegetation, soils, or water pollution, 9-inch cameras often exceed accuracy and cost requirements, and small formats may be better. In choosing the best camera for environmental mapping, relative capabilities and costs must be understood. This study compares resolution, photo interpretation potential, metric accuracy, and cost of 9-inch, 70mm, and 35mm cameras for obtaining simultaneous color and color infrared photography for environmental mapping purposes.

  9. Bilingual Knowledge Maps (BiK Maps) as a Presentation Format: Delayed Recall and Training Effects

    ERIC Educational Resources Information Center

    Bahr, G. Sussane; Dansereau, Donald F.

    2005-01-01

    The use of bilingual graphic organizers (bilingual knowledge maps [BiK maps]) as a presentation format was investigated for the acquisition of foreign language vocabulary. Participants were assigned to 1 of 4 conditions for the task of studying 32 German-English word pairs. Participants in each condition were trained on either lists or BiK maps…

  10. The effect of intracortical competition on the formation of topographic maps in models of Hebbian learning.

    PubMed

    Piepenbrock, C; Obermayer, K

    2000-04-01

    Correlation-based learning (CBL) models and self-organizing maps (SOM) are two classes of Hebbian models that have both been proposed to explain the activity-driven formation of cortical maps. Both models differ significantly in the way lateral cortical interactions are treated, leading to different predictions for the formation of receptive fields. The linear CBL models predict that receptive field profiles are determined by the average values and the spatial correlations of the second order of the afferent activity patterns, whereas SOM models map stimulus features. Here, we investigate a class of models which are characterized by a variable degree of lateral competition and which have the CBL and SOM models as limit cases. We show that there exists a critical value for intracortical competition below which the model exhibits CBL properties and above which feature mapping sets in. The class of models is then analyzed with respect to the formation of topographic maps between two layers of neurons. For Gaussian input stimuli we find that localized receptive fields and topographic maps emerge above the critical value for intracortical competition, and we calculate this value as a function of the size of the input stimuli and the range of the lateral interaction function. Additionally, we show that the learning rule can be derived via the optimization of a global cost function in a framework of probabilistic output neurons which represent a set of input stimuli by a sparse code.

  11. Can Selforganizing Maps Accurately Predict Photometric Redshifts?

    NASA Technical Reports Server (NTRS)

    Way, Michael J.; Klose, Christian

    2012-01-01

    We present an unsupervised machine-learning approach that can be employed for estimating photometric redshifts. The proposed method is based on a vector quantization called the self-organizing-map (SOM) approach. A variety of photometrically derived input values were utilized from the Sloan Digital Sky Survey's main galaxy sample, luminous red galaxy, and quasar samples, along with the PHAT0 data set from the Photo-z Accuracy Testing project. Regression results obtained with this new approach were evaluated in terms of root-mean-square error (RMSE) to estimate the accuracy of the photometric redshift estimates. The results demonstrate competitive RMSE and outlier percentages when compared with several other popular approaches, such as artificial neural networks and Gaussian process regression. SOM RMSE results (using delta(z) = z(sub phot) - z(sub spec)) are 0.023 for the main galaxy sample, 0.027 for the luminous red galaxy sample, 0.418 for quasars, and 0.022 for PHAT0 synthetic data. The results demonstrate that there are nonunique solutions for estimating SOM RMSEs. Further research is needed in order to find more robust estimation techniques using SOMs, but the results herein are a positive indication of their capabilities when compared with other well-known methods

  12. Predicting Tick Presence by Environmental Risk Mapping

    PubMed Central

    Swart, Arno; Ibañez-Justicia, Adolfo; Buijs, Jan; van Wieren, Sip E.; Hofmeester, Tim R.; Sprong, Hein; Takumi, Katsuhisa

    2014-01-01

    Public health statistics recorded an increasing trend in the incidence of tick bites and erythema migrans (EM) in the Netherlands. We investigated whether the disease incidence could be predicted by a spatially explicit categorization model, based on environmental factors and a training set of tick absence–presence data. Presence and absence of Ixodes ricinus were determined by the blanket-dragging method at numerous sites spread over the Netherlands. The probability of tick presence on a 1 km by 1 km square grid was estimated from the field data using a satellite-based methodology. Expert elicitation was conducted to provide a Bayesian prior per landscape type. We applied a linear model to test for a linear relationship between incidence of EM consultations by general practitioners in the Netherlands and the estimated probability of tick presence. Ticks were present at 252 distinct sampling coordinates and absent at 425. Tick presence was estimated for 54% of the total land cover. Our model has predictive power for tick presence in the Netherlands, tick-bite incidence per municipality correlated significantly with the average probability of tick presence per grid. The estimated intercept of the linear model was positive and significant. This indicates that a significant fraction of the tick-bite consultations could be attributed to the I. ricinus population outside the resident municipality. PMID:25505781

  13. Development of predictive mapping techniques for soil survey and salinity mapping

    NASA Astrophysics Data System (ADS)

    Elnaggar, Abdelhamid A.

    Conventional soil maps represent a valuable source of information about soil characteristics, however they are subjective, very expensive, and time-consuming to prepare. Also, they do not include explicit information about the conceptual mental model used in developing them nor information about their accuracy, in addition to the error associated with them. Decision tree analysis (DTA) was successfully used in retrieving the expert knowledge embedded in old soil survey data. This knowledge was efficiently used in developing predictive soil maps for the study areas in Benton and Malheur Counties, Oregon and accessing their consistency. A retrieved soil-landscape model from a reference area in Harney County was extrapolated to develop a preliminary soil map for the neighboring unmapped part of Malheur County. The developed map had a low prediction accuracy and only a few soil map units (SMUs) were predicted with significant accuracy, mostly those shallow SMUs that have either a lithic contact with the bedrock or developed on a duripan. On the other hand, the developed soil map based on field data was predicted with very high accuracy (overall was about 97%). Salt-affected areas of the Malheur County study area are indicated by their high spectral reflectance and they are easily discriminated from the remote sensing data. However, remote sensing data fails to distinguish between the different classes of soil salinity. Using the DTA method, five classes of soil salinity were successfully predicted with an overall accuracy of about 99%. Moreover, the calculated area of salt-affected soil was overestimated when mapped using remote sensing data compared to that predicted by using DTA. Hence, DTA could be a very helpful approach in developing soil survey and soil salinity maps in more objective, effective, less-expensive and quicker ways based on field data.

  14. Bifurcation of learning and structure formation in neuronal maps

    NASA Astrophysics Data System (ADS)

    Marschler, Christian; Faust-Ellsässer, Carmen; Starke, Jens; van Hemmen, J. Leo

    2014-11-01

    Most learning processes in neuronal networks happen on a much longer time scale than that of the underlying neuronal dynamics. It is therefore useful to analyze slowly varying macroscopic order parameters to explore a network's learning ability. We study the synaptic learning process giving rise to map formation in the laminar nucleus of the barn owl's auditory system. Using equation-free methods, we perform a bifurcation analysis of spatio-temporal structure formation in the associated synaptic-weight matrix. This enables us to analyze learning as a bifurcation process and follow the unstable states as well. A simple time translation of the learning window function shifts the bifurcation point of structure formation and goes along with traveling waves in the map, without changing the animal's sound localization performance.

  15. Temporal Map Formation in the Barn Owl's Brain

    NASA Astrophysics Data System (ADS)

    Leibold, Christian; Kempter, Richard; van Hemmen, J. Leo

    2001-12-01

    Barn owls provide an experimentally well-specified example of a temporal map, a neuronal representation of the outside world in the brain by means of time. Their laminar nucleus exhibits a place code of interaural time differences, a cue which is used to determine the azimuthal location of a sound stimulus, e.g., prey. We analyze a model of synaptic plasticity that explains the formation of such a representation in the young bird and show how in a large parameter regime a combination of local and nonlocal synaptic plasticity yields the temporal map as found experimentally. Our analysis includes the effect of nonlinearities as well as the influence of neuronal noise.

  16. Evaluating the Quality of Predictive Geological Maps Produced using Self-Organizing Maps

    NASA Astrophysics Data System (ADS)

    Carter-McAuslan, Angela; Farquharson, Colin

    2016-04-01

    With increased data collection, extraction of useful information from large, often multi-dimensional (where each dimension is a unique data-type), datasets becomes a challenge. Associated with the problem of extracting usable information is the need to evaluate the information extracted to determine its validity. Traditionally, geophysical data has been interpreted in map or profile form one data-type at a time using primarily visual inspection by the interpreter. This approach become increasingly difficult as the dimensionality (e.g. number of data-types) of the dataset is increased. As such, new methods for discovering patterns in multi-dimensional geophysical datasets need to be investigated. Self-organizing maps (SOMs) are a class of unsupervised artificial neural network algorithm which are used to cluster multi-dimensional data while preserving the overall topology of the original dataset. As geophysical responses measured in the field are closely linked to the local geology it is postulated that SOMs can be employed to cluster multi-dimensional geophysical data in order to produce predictive geological maps. In the development of an effective work flow for creating predictive geological maps using SOMs, synthetic and real world test cases are used so that the predictive maps can be compared to a known geology. This comparison can be done through visual inspection. However, quantitative measures of clustering quality are also desired. In this project three different types of cluster quality measures are investigated: cluster morphology measures (e.g. the Quantization Error and the Dunn Index); class/cluster concatenation measures (e.g. Cluster Purity and Normalized Mutual Information); and decision-based measures (e.g. the Rand Index and F-Measure). SOM predictive mapping was applied to mapping the Baie Verte Peninsula on the north coast of the island of Newfoundland, Canada. The Baie Verte Peninsula is a region of complex geology with good regional

  17. Histopathology Predicts the Mechanism of Stone Formation

    NASA Astrophysics Data System (ADS)

    Evan, Andrew P.

    2007-04-01

    About 5% of American women and 12% of men will develop a kidney stone at some time in their life and these numbers appear to be on the rise. Despite years of scientific research into the mechanisms of stone formation and growth, limited advances have been made until recently. Randall's original observations and thoughts on the mechanisms for kidney stone formation have been validated for idiopathic calcium oxalate stone formers (ICSF) but not for most other stone forming groups. Our current studies on selected groups of human stone formers using intraoperative papillary biopsies has shown overwhelming evidence for the presence of Randall's plaque in ICSF and that stone formation and growth are exclusively linked to its availability to urinary ions and proteins. Intense investigation of the plaque-stone junction is needed if we are to understand the factors leading to the overgrowth process on exposed regions of plaque. Such information should allow the development of treatment strategies to block stone formation in ICSF patients. Patients who form brushite stones, or who form apatite stones because of distal renal tubular acidosis (dRTA), or patients with calcium oxalate stones due to obesity bypass procedures, or patients with cystinuria, get plugged inner medullary collecting ducts (IMCD) which leads to total destruction of the lining cells and focal sites of interstitial fibrosis. These stone formers have plaque but at levels equal to or below non-stone formers, which would suggest that they form stones by a different mechanism than do ICSF patients.

  18. Predicting episodic memory formation for movie events

    PubMed Central

    Tang, Hanlin; Singer, Jed; Ison, Matias J.; Pivazyan, Gnel; Romaine, Melissa; Frias, Rosa; Meller, Elizabeth; Boulin, Adrianna; Carroll, James; Perron, Victoria; Dowcett, Sarah; Arellano, Marlise; Kreiman, Gabriel

    2016-01-01

    Episodic memories are long lasting and full of detail, yet imperfect and malleable. We quantitatively evaluated recollection of short audiovisual segments from movies as a proxy to real-life memory formation in 161 subjects at 15 minutes up to a year after encoding. Memories were reproducible within and across individuals, showed the typical decay with time elapsed between encoding and testing, were fallible yet accurate, and were insensitive to low-level stimulus manipulations but sensitive to high-level stimulus properties. Remarkably, memorability was also high for single movie frames, even one year post-encoding. To evaluate what determines the efficacy of long-term memory formation, we developed an extensive set of content annotations that included actions, emotional valence, visual cues and auditory cues. These annotations enabled us to document the content properties that showed a stronger correlation with recognition memory and to build a machine-learning computational model that accounted for episodic memory formation in single events for group averages and individual subjects with an accuracy of up to 80%. These results provide initial steps towards the development of a quantitative computational theory capable of explaining the subjective filtering steps that lead to how humans learn and consolidate memories. PMID:27686330

  19. Predictions from star formation in the multiverse

    SciTech Connect

    Bousso, Raphael; Leichenauer, Stefan

    2010-03-15

    We compute trivariate probability distributions in the landscape, scanning simultaneously over the cosmological constant, the primordial density contrast, and spatial curvature. We consider two different measures for regulating the divergences of eternal inflation, and three different models for observers. In one model, observers are assumed to arise in proportion to the entropy produced by stars; in the others, they arise at a fixed time (5 or 10x10{sup 9} years) after star formation. The star formation rate, which underlies all our observer models, depends sensitively on the three scanning parameters. We employ a recently developed model of star formation in the multiverse, a considerable refinement over previous treatments of the astrophysical and cosmological properties of different pocket universes. For each combination of observer model and measure, we display all single and bivariate probability distributions, both with the remaining parameter(s) held fixed and marginalized. Our results depend only weakly on the observer model but more strongly on the measure. Using the causal diamond measure, the observed parameter values (or bounds) lie within the central 2{sigma} of nearly all probability distributions we compute, and always within 3{sigma}. This success is encouraging and rather nontrivial, considering the large size and dimension of the parameter space. The causal patch measure gives similar results as long as curvature is negligible. If curvature dominates, the causal patch leads to a novel runaway: it prefers a negative value of the cosmological constant, with the smallest magnitude available in the landscape.

  20. Predicting and mapping soil available water capacity in Korea

    PubMed Central

    Hong, Suk Young; Han, Kyung Hwa; Kim, Yihyun; Lee, Kyungdo

    2013-01-01

    The knowledge on the spatial distribution of soil available water capacity at a regional or national extent is essential, as soil water capacity is a component of the water and energy balances in the terrestrial ecosystem. It controls the evapotranspiration rate, and has a major impact on climate. This paper demonstrates a protocol for mapping soil available water capacity in South Korea at a fine scale using data available from surveys. The procedures combined digital soil mapping technology with the available soil map of 1:25,000. We used the modal profile data from the Taxonomical Classification of Korean Soils. The data consist of profile description along with physical and chemical analysis for the modal profiles of the 380 soil series. However not all soil samples have measured bulk density and water content at −10 and −1500 kPa. Thus they need to be predicted using pedotransfer functions. Furthermore, water content at −10 kPa was measured using ground samples. Thus a correction factor is derived to take into account the effect of bulk density. Results showed that Andisols has the highest mean water storage capacity, followed by Entisols and Inceptisols which have loamy texture. The lowest water retention is Entisols which are dominated by sandy materials. Profile available water capacity to a depth of 1 m was calculated and mapped for Korea. The western part of the country shows higher available water capacity than the eastern part which is mountainous and has shallower soils. The highest water storage capacity soils are the Ultisols and Alfisols (mean of 206 and 205 mm, respectively). Validation of the maps showed promising results. The map produced can be used as an indication of soil physical quality of Korean soils. PMID:23646290

  1. Bimetric structure formation: Non-Gaussian predictions

    SciTech Connect

    Magueijo, Joao; Noller, Johannes; Piazza, Federico

    2010-08-15

    The minimal bimetric theory employing a disformal transformation between matter and gravity metrics is known to produce exactly scale-invariant fluctuations. It has a purely equilateral non-Gaussian signal, with an amplitude smaller than that of Dirac Born Infeld inflation (with opposite sign) but larger than standard inflation. We consider nonminimal bimetric models, where the coupling B appearing in the disformal transformation g-circumflex{sub {mu}{nu}}=g{sub {mu}{nu}}-B{partial_derivative}{sub {mu}{phi}{partial_derivative}{nu}{phi}} can run with {phi}. For power-law B({phi}) these models predict tilted spectra. For each value of the spectral index, a distinctive distortion to the equilateral property can be found. The constraint between this distortion and the spectral index can be seen as a 'consistency relation' for nonminimal bimetric models.

  2. Bimetric structure formation: Non-Gaussian predictions

    NASA Astrophysics Data System (ADS)

    Magueijo, João; Noller, Johannes; Piazza, Federico

    2010-08-01

    The minimal bimetric theory employing a disformal transformation between matter and gravity metrics is known to produce exactly scale-invariant fluctuations. It has a purely equilateral non-Gaussian signal, with an amplitude smaller than that of Dirac Born Infeld inflation (with opposite sign) but larger than standard inflation. We consider nonminimal bimetric models, where the coupling B appearing in the disformal transformation g^μν=gμν-B∂μϕ∂νϕ can run with ϕ. For power-law B(ϕ) these models predict tilted spectra. For each value of the spectral index, a distinctive distortion to the equilateral property can be found. The constraint between this distortion and the spectral index can be seen as a “consistency relation” for nonminimal bimetric models.

  3. Mapping of Estimations and Prediction Intervals Using Extreme Learning Machines

    NASA Astrophysics Data System (ADS)

    Leuenberger, Michael; Kanevski, Mikhail

    2015-04-01

    Due to the large amount and complexity of data available nowadays in environmental sciences, we face the need to apply more robust methodology allowing analyses and understanding of the phenomena under study. One particular but very important aspect of this understanding is the reliability of generated prediction models. From the data collection to the prediction map, several sources of error can occur and affect the final result. Theses sources are mainly identified as uncertainty in data (data noise), and uncertainty in the model. Their combination leads to the so-called prediction interval. Quantifying these two categories of uncertainty allows a finer understanding of phenomena under study and a better assessment of the prediction accuracy. The present research deals with a methodology combining a machine learning algorithm (ELM - Extreme Learning Machine) with a bootstrap-based procedure. Developed by G.-B. Huang et al. (2006), ELM is an artificial neural network following the structure of a multilayer perceptron (MLP) with one single hidden layer. Compared to classical MLP, ELM has the ability to learn faster without loss of accuracy, and need only one hyper-parameter to be fitted (that is the number of nodes in the hidden layer). The key steps of the proposed method are as following: sample from the original data a variety of subsets using bootstrapping; from these subsets, train and validate ELM models; and compute residuals. Then, the same procedure is performed a second time with only the squared training residuals. Finally, taking into account the two modeling levels allows developing the mean prediction map, the model uncertainty variance, and the data noise variance. The proposed approach is illustrated using geospatial data. References Efron B., and Tibshirani R. 1986, Bootstrap Methods for Standard Errors, Confidence Intervals, and Other Measures of Statistical accuracy, Statistical Science, vol. 1: 54-75. Huang G.-B., Zhu Q.-Y., and Siew C.-K. 2006

  4. Statistical-mechanical analysis of self-organization and pattern formation during the development of visual maps

    NASA Astrophysics Data System (ADS)

    Obermayer, K.; Blasdel, G. G.; Schulten, K.

    1992-05-01

    We report a detailed analytical and numerical model study of pattern formation during the development of visual maps, namely, the formation of topographic maps and orientation and ocular dominance columns in the striate cortex. Pattern formation is described by a stimulus-driven Markovian process, the self-organizing feature map. This algorithm generates topologically correct maps between a space of (visual) input signals and an array of formal ``neurons,'' which in our model represents the cortex. We define order parameters that are a function of the set of visual stimuli an animal perceives, and we demonstrate that the formation of orientation and ocular dominance columns is the result of a global instability of the retinoptic projection above a critical value of these order parameters. We characterize the spatial structure of the emerging patterns by power spectra, correlation functions, and Gabor transforms, and we compare model predictions with experimental data obtained from the striate cortex of the macaque monkey with optical imaging. Above the critical value of the order parameters the model predicts a lateral segregation of the striate cortex into (i) binocular regions with linear changes in orientation preference, where iso-orientation slabs run perpendicular to the ocular dominance bands, and (ii) monocular regions with low orientation specificity, which contain the singularities of the orientation map. Some of these predictions have already been verified by experiments.

  5. Formation and evolution of Lakshmi Planum, Venus: Assessment of models using observations from geological mapping

    NASA Astrophysics Data System (ADS)

    Ivanov, M. A.; Head, J. W.

    2008-12-01

    Detailed geological analysis of the Lakshmi Planum region of western Ishtar Terra results in the establishment of the sequence of major events during the formation and evolution of western Ishtar Terra, an important and somewhat unique area on Venus characterized by a raised volcanic plateau surrounded by distinctive folded mountain belts, such as Maxwell Montes. These mapping results and the stratigraphic and structural relationships provide a basis for addressing the complicated problem of Lakshmi Planum formation and for testing the suite of models previously proposed to explain this structure. We review and classify previous models of formation for western Ishtar Terra into "downwelling" models (generally involving convergence and underthrusting) and "upwelling" models (generally involving plume-like upwelling and divergence). The interpreted nature of units and the sequence of events derived from geological mapping are in contrast to the predictions of the divergent models. The major contradictions are as follows: (1) The very likely presence of an ancient (craton-like) tessera massif in the core of Lakshmi, which is inconsistent with the model of formation of Lakshmi due to rise and collapse of a mantle diapir; (2) The absence of rift zones in the interior of Lakshmi that are predicted by the divergent models; (3) The apparent migration of volcanic activity toward the center of Lakshmi, whereas divergent models predict the opposite trend; (4) The abrupt cessation of ridges of the mountain ranges at the edge of Lakshmi Planum and propagation of these ridges over hundreds of kilometers outside Lakshmi; the divergent models predict the opposite progression in the development of major contractional features. In contrast, convergent models of formation and evolution of Lakshmi Planum appear to be more consistent with the observations and explain this structure by collision and underthrusting/subduction of lower-lying plains with the elevated and rigid block of

  6. Evaluation of current statistical approaches for predictive geomorphological mapping

    NASA Astrophysics Data System (ADS)

    Miska, Luoto; Jan, Hjort

    2005-04-01

    Predictive models are increasingly used in geomorphology, but systematic evaluations of novel statistical techniques are still limited. The aim of this study was to compare the accuracy of generalized linear models (GLM), generalized additive models (GAM), classification tree analysis (CTA), neural networks (ANN) and multiple adaptive regression splines (MARS) in predictive geomorphological modelling. Five different distribution models both for non-sorted and sorted patterned ground were constructed on the basis of four terrain parameters and four soil variables. To evaluate the models, the original data set of 9997 squares of 1 ha in size was randomly divided into model training (70%, n=6998) and model evaluation sets (30%, n=2999). In general, active sorted patterned ground is clearly defined in upper fell areas with high slope angle and till soils. Active non-sorted patterned ground is more common in valleys with higher soil moisture and fine-scale concave topography. The predictive performance of each model was evaluated using the area under the receiver operating characteristic curve (AUC) and the Kappa value. The relatively high discrimination capacity of all models, AUC=0.85 0.88 and Kappa=0.49 0.56, implies that the model's predictions provide an acceptable index of sorted and non-sorted patterned ground occurrence. The best performance for model calibration data for both data sets was achieved by the CTA. However, when the predictive mapping ability was explored through the evaluation data set, the model accuracies of CTA decreased clearly compared to the other modelling techniques. For model evaluation data MARS performed marginally best. Our results show that the digital elevation model and soil data can be used to predict relatively robustly the activity of patterned ground in fine scale in a subarctic landscape. This indicates that predictive geomorphological modelling has the advantage of providing relevant and useful information on earth surface

  7. Using dominant eigenvalue analysis to predict formation of alternans in the heart

    NASA Astrophysics Data System (ADS)

    Kakade, Virendra; Zhao, Xiaopeng; Tolkacheva, Elena G.

    2013-11-01

    Ventricular fibrillation at the whole heart level is often preceded by the alternation of action potential duration (APD), i.e., alternans, at the cellular level. As proven in many experiments, traditional approaches based on the slope of the restitution curve have not been successful in predicting alternans formation. Recently, a technique has been theoretically developed based on dominant eigenvalue analysis to predict alternans formation in isolated cardiac myocytes. Here, we aimed to demonstrate that this technique can be applied to predict alternans formation at the whole heart level. Optical mapping was performed in Langendorff-perfused hearts from New Zealand white rabbits (n = 4), which were paced at decreasing basic cycle lengths to introduce APD alternans. In each heart, the basic cycle length corresponding to the local onset of alternans, Bonset, was determined and two regions of the heart were identified at Bonset: one region which exhibited alternans (1:1alt) and one which did not (1:1). Corresponding two-dimensional eigenvalue (λ) maps were generated using principal component analysis by analyzing action potentials after short perturbations from the steady state, and mean eigenvalues (λ¯) were calculated separately for the 1:1 and 1:1alt regions. We demonstrated that λ¯ calculated at Bonset was significantly different (p<0.05) between the two regions. Our results suggest that this dominant eigenvalue technique can be used to successfully predict the local alternans formation in the heart.

  8. Flood Water Level Mapping and Prediction Due to Dam Failures

    NASA Astrophysics Data System (ADS)

    Musa, S.; Adnan, M. S.; Ahmad, N. A.; Ayob, S.

    2016-07-01

    Sembrong dam has undergone overflow failure. Flooding has been reported to hit the town, covering an area of up to Parit Raja, located in the district of Batu Pahat. This study aims to identify the areas that will be affected by flood in the event of a dam failure in Sembrong Dam, Kluang, Johor at a maximum level. To grasp the extent, the flood inundation maps have been generated by using the InfoWorks ICM and GIS software. By using these maps, information such as the depth and extent of floods can be identified the main ares flooded. The flood map was created starting with the collection of relevant data such as measuring the depth of the river and a maximum flow rate for Sembrong Dam. The data were obtained from the Drainage and Irrigation Department Malaysia and the Department of Survey and Mapping and HLA Associates Sdn. Bhd. Then, the data were analyzed according to the established Info Works ICM method. The results found that the flooded area were listed at Sri Lalang, Parit Sagil, Parit Sonto, Sri Paya, Parit Raja, Parit Sempadan, Talang Bunut, Asam Bubok, Tanjung Sembrong, Sungai Rambut and Parit Haji Talib. Flood depth obtained for the related area started from 0.5 m up to 1.2 m. As a conclusion, the flood emanating from this study include the area around the town of Ayer Hitam up to Parit Raja approximately of more than 20 km distance. This may give bad implication to residents around these areas. In future studies, other rivers such as Sungai Batu Pahat should be considered for this study to predict and reduce the yearly flood victims for this area.

  9. Detailed forest formation mapping in the land cover map series for the Caribbean islands

    NASA Astrophysics Data System (ADS)

    Helmer, E. H.; Schill, S.; Pedreros, D. H.; Tieszen, L. L.; Kennaway, T.; Cushing, M.; Ruzycki, T.

    2006-12-01

    Forest formation and land cover maps for several Caribbean islands were developed from Landsat ETM+ imagery as part of a multi-organizational project. The spatially explicit data on forest formation types will permit more refined estimates of some forest attributes. The woody vegetation classification scheme relates closely to that of Areces-Malea et al. (1), who classify Caribbean vegetation according to standards of the US Federal Geographic Data Committee (FGDC, 1997), with modifications similar to those in Helmer et al. (2). For several of the islands, we developed image mosaics that filled cloudy parts of scenes with data from other scene dates after using regression tree normalization (3). The regression tree procedure permitted us to develop mosaics for wet and drought seasons for a few of the islands. The resulting multiseason imagery facilitated separation between classes such as seasonal evergreen forest, semi-deciduous forest (including semi-evergreen forest), and drought deciduous forest or woodland formations. We used decision tree classification methods to classify the Landsat image mosaics to detailed forest formations and land cover for Puerto Rico (4), St. Kitts and Nevis, St. Lucia, St. Vincent and the Grenadines and Grenada. The decision trees classified a stack of raster layers for each mapping area that included the Landsat image bands and various ancillary raster data layers. For Puerto Rico, for example, the ancillary data included climate parameters (5). For some islands, the ancillary data included topographic derivatives such as aspect, slope and slope position, SRTM (6) or other topographic data. Mapping forest formations with decision tree classifiers, ancillary geospatial data, and cloud-free image mosaics, accurately distinguished spectrally similar forest formations, without the aid of ecological zone maps, on the islands where the approach was used. The approach resulted in maps of forest formations with comparable or better detail

  10. Mapping Extinction and Star Formation Rates of Nearby Galaxies

    NASA Astrophysics Data System (ADS)

    Ridenour, Anthony; Takamiya, M.

    2010-01-01

    Star Formation Rate (SFR) is a physical characteristic of galaxies vital to our understanding of such problems as the evolution of the Universe. In computing SFRs obscuring dust systematically lowers them at shorter wavelengths compared to longer wavelengths. This issue of dust extinction has been handled well by multi-wavelength studies of nearby galaxies. Star Formation Rate measurements of distant galaxies are currently reliant on the emission of visible spectroscopic lines like Hα and [OII] after correction for extinction. However, if the visible light is completely obscured an incorrect assumption may be drawn; namely that there is neither SFR nor extinction. The work purposed here is to calibrate the SFR ascertained from Hα emission in nearby galaxies and compare it to radio and infrared emission. The Balmer decrement, or the ratio of Hβ to Hα emission, used to determine extinction, will also be studied and compared to infrared images. 30 nearby galaxies will be sampled and 2-D maps and Balmer decrements will be formed to do two things: measure SFRs and determine differences between Hα and infrared emission, and explore in what ways this difference corresponds with such things as the radio SFR, galaxy luminosity and morphological type. The accuracy of Hα as a SFR indicator and its determination as a sound tool in measuring SFRs of distant galaxies can both be quantified by interpreting these maps. Dr. Marianne Takamiya, the principal investigator and my mentor, secured funds through a grant to the University of Hawai'i at Hilo from The Research Corporation for Science Advancement Cottrell College Science Awards for this research.

  11. Autonomous formation flight of helicopters: Model predictive control approach

    NASA Astrophysics Data System (ADS)

    Chung, Hoam

    Formation flight is the primary movement technique for teams of helicopters. However, the potential for accidents is greatly increased when helicopter teams are required to fly in tight formations and under harsh conditions. This dissertation proposes that the automation of helicopter formations is a realistic solution capable of alleviating risks. Helicopter formation flight operations in battlefield situations are highly dynamic and dangerous, and, therefore, we maintain that both a high-level formation management system and a distributed coordinated control algorithm should be implemented to help ensure safe formations. The starting point for safe autonomous formation flights is to design a distributed control law attenuating external disturbances coming into a formation, so that each vehicle can safely maintain sufficient clearance between it and all other vehicles. While conventional methods are limited to homogeneous formations, our decentralized model predictive control (MPC) approach allows for heterogeneity in a formation. In order to avoid the conservative nature inherent in distributed MPC algorithms, we begin by designing a stable MPC for individual vehicles, and then introducing carefully designed inter-agent coupling terms in a performance index. Thus the proposed algorithm works in a decentralized manner, and can be applied to the problem of helicopter formations comprised of heterogenous vehicles. Individual vehicles in a team may be confronted by various emerging situations that will require the capability for in-flight reconfiguration. We propose the concept of a formation manager to manage separation, join, and synchronization of flight course changes. The formation manager accepts an operator's commands, information from neighboring vehicles, and its own vehicle states. Inside the formation manager, there are multiple modes and complex mode switchings represented as a finite state machine (FSM). Based on the current mode and collected

  12. Literal grid map models for animal navigation: Assumptions and predictions.

    PubMed

    Turner, Rebecca M; Walker, Michael M; Postlethwaite, Claire M

    2016-09-01

    Many animals can navigate from unfamiliar locations to a familiar target location with no outward route information or direct sensory contact with the target or any familiar landmarks. Several models have been proposed to explain this phenomenon, one possibility being a literal interpretation of a grid map. In this paper we systematically compare four such models, which we label: Correct Bicoordinate navigation, both Target and Release site based, Approximate Bicoordinate navigation, and Directional navigation. Predictions of spatial patterns of initial orientation errors and efficiencies depend on a combination of assumptions about the navigation mechanism and the geometry of the environmental coordinate fields used as model inputs. When coordinates axes are orthogonal at the target the predictions from the Correct Bicoordinate (Target based) model and Approximate Bicoordinate model are identical. However, if the coordinate axes are non-orthogonal different regional patterns of initial orientation errors and efficiencies can be expected from these two models. Field anomalies produce high magnitudes of orientation errors close to the target, while region-wide nonlinearity leads to orientation errors increasing with distance from the target. In general, initial orientation error patterns are more useful for distinguishing between different assumption combinations than efficiencies. We discuss how consideration of model predictions may be helpful in the design of experiments.

  13. Literal grid map models for animal navigation: Assumptions and predictions.

    PubMed

    Turner, Rebecca M; Walker, Michael M; Postlethwaite, Claire M

    2016-09-01

    Many animals can navigate from unfamiliar locations to a familiar target location with no outward route information or direct sensory contact with the target or any familiar landmarks. Several models have been proposed to explain this phenomenon, one possibility being a literal interpretation of a grid map. In this paper we systematically compare four such models, which we label: Correct Bicoordinate navigation, both Target and Release site based, Approximate Bicoordinate navigation, and Directional navigation. Predictions of spatial patterns of initial orientation errors and efficiencies depend on a combination of assumptions about the navigation mechanism and the geometry of the environmental coordinate fields used as model inputs. When coordinates axes are orthogonal at the target the predictions from the Correct Bicoordinate (Target based) model and Approximate Bicoordinate model are identical. However, if the coordinate axes are non-orthogonal different regional patterns of initial orientation errors and efficiencies can be expected from these two models. Field anomalies produce high magnitudes of orientation errors close to the target, while region-wide nonlinearity leads to orientation errors increasing with distance from the target. In general, initial orientation error patterns are more useful for distinguishing between different assumption combinations than efficiencies. We discuss how consideration of model predictions may be helpful in the design of experiments. PMID:27266672

  14. nuMap: a web platform for accurate prediction of nucleosome positioning.

    PubMed

    Alharbi, Bader A; Alshammari, Thamir H; Felton, Nathan L; Zhurkin, Victor B; Cui, Feng

    2014-10-01

    Nucleosome positioning is critical for gene expression and of major biological interest. The high cost of experimentally mapping nucleosomal arrangement signifies the need for computational approaches to predict nucleosome positions at high resolution. Here, we present a web-based application to fulfill this need by implementing two models, YR and W/S schemes, for the translational and rotational positioning of nucleosomes, respectively. Our methods are based on sequence-dependent anisotropic bending that dictates how DNA is wrapped around a histone octamer. This application allows users to specify a number of options such as schemes and parameters for threading calculation and provides multiple layout formats. The nuMap is implemented in Java/Perl/MySQL and is freely available for public use at http://numap.rit.edu. The user manual, implementation notes, description of the methodology and examples are available at the site. PMID:25220945

  15. The geologic mapping of Venus using C-1 format: Sheets 75N254, 60N263

    NASA Technical Reports Server (NTRS)

    Shalimov, I. V.

    1992-01-01

    The results of geologic mapping of Venus, produced on the base of Magellan images, are presented. We submit two C-1 format geologic maps with the appropriate legend. The mapping territory was taken from Venera 15 and 16 missions and geologic maps were composed. Magellan images allow us to divide some types of the plains units to determine the lava flow direction and to map with better accuracy.

  16. Connecting CO intensity mapping to molecular gas and star formation in the epoch of galaxy assembly

    DOE PAGES

    Li, Tony Y.; Wechsler, Risa H.; Devaraj, Kiruthika; Church, Sarah E.

    2016-01-29

    Intensity mapping, which images a single spectral line from unresolved galaxies across cosmological volumes, is a promising technique for probing the early universe. Here we present predictions for the intensity map and power spectrum of the CO(1–0) line from galaxies atmore » $$z\\sim 2.4$$–2.8, based on a parameterized model for the galaxy–halo connection, and demonstrate the extent to which properties of high-redshift galaxies can be directly inferred from such observations. We find that our fiducial prediction should be detectable by a realistic experiment. Motivated by significant modeling uncertainties, we demonstrate the effect on the power spectrum of varying each parameter in our model. Using simulated observations, we infer constraints on our model parameter space with an MCMC procedure, and show corresponding constraints on the $${L}_{\\mathrm{IR}}$$–$${L}_{\\mathrm{CO}}$$ relation and the CO luminosity function. These constraints would be complementary to current high-redshift galaxy observations, which can detect the brightest galaxies but not complete samples from the faint end of the luminosity function. Furthermore, by probing these populations in aggregate, CO intensity mapping could be a valuable tool for probing molecular gas and its relation to star formation in high-redshift galaxies.« less

  17. Predictive mapping of the natural flow regimes of France

    NASA Astrophysics Data System (ADS)

    Snelder, Ton H.; Lamouroux, Nicolas; Leathwick, John R.; Pella, Hervé; Sauquet, Eric; Shankar, Ude

    2009-06-01

    SummaryHydrologic variability is important in sustaining a variety of ecological processes in streams and rivers. Natural flow regime classifications group streams and rivers that are relatively homogeneous with respect to flow variability and have been promoted as a method of defining units for management of river flows. Although there has been considerable interest in classifying natural flow regimes, there has been less emphasis given to developing accurate methods of extrapolating these classifications to locations without flow data. We developed a method of mapping flow regime classes using boosted regression trees (BRT) that automatically fits non-linear functions and interactions between explanatory variables of flow regimes, both of which can be expected when comparing responses between complex systems such as watersheds. A natural flow regimes classification of continental France was developed from cluster analysis of 157 hydrological indices derived from 763 gauging stations representing unmodified flows. BRT models were used to predict the likelihood of gauging stations belonging to each class based on the watershed characteristics. These models were used to extrapolate the natural flow regime classification to all segments of a national river network. The performance of the BRT models were compared with other methods of assigning locations to flow regime classes, including the use of geographically contiguous regions, linear discriminant analysis (LDA) and classification and regression trees (CART). The "fitted" misclassification rate (associated with model fits) for assignment based on the BRT models was 13% whereas the fitted misclassification rates for geographically contiguous regions, LDA and CART were 52%, 44% and 39% respectively. A "predictive" misclassification rate (calculated for new cases) was estimated for assignments based on the BRT, LDA and CART models using cross validation analysis. For assignment based on the BRT models, the mean

  18. Predictive mapping of prospectivity for orogenic gold in Uganda

    NASA Astrophysics Data System (ADS)

    Herbert, Sarah; Woldai, Tsehaie; Carranza, Emmanuel John M.; van Ruitenbeek, Frank J. A.

    2014-11-01

    -driven multi-class index overlay method was used to integrate predictor layers representing those processes in order to model orogenic gold prospectivity into a single map. Weighting of the predictor layers, prior to integration, occurs at the level of the critical process and takes into account the relative importance of the critical process mineralisation, the representativeness of a proxy and the accuracy of the proxy. The resultant prospectivity model shows that 83% of all gold occurrences are delineated within predicted prospective areas covering 30% of the study area. Eight sub-areas, covering 2500 km2, have been recommended for follow-up exploration.

  19. QSPR for predicting chloroform formation in drinking water disinfection.

    PubMed

    Luilo, G B; Cabaniss, S E

    2011-01-01

    Chlorination is the most widely used technique for water disinfection, but may lead to the formation of chloroform (trichloromethane; TCM) and other by-products. This article reports the first quantitative structure-property relationship (QSPR) for predicting the formation of TCM in chlorinated drinking water. Model compounds (n = 117) drawn from 10 literature sources were divided into training data (n = 90, analysed by five-way leave-many-out internal cross-validation) and external validation data (n = 27). QSPR internal cross-validation had Q² = 0.94 and root mean square error (RMSE) of 0.09 moles TCM per mole compound, consistent with external validation Q2 of 0.94 and RMSE of 0.08 moles TCM per mole compound, and met criteria for high predictive power and robustness. In contrast, log TCM QSPR performed poorly and did not meet the criteria for predictive power. The QSPR predictions were consistent with experimental values for TCM formation from tannic acid and for model fulvic acid structures. The descriptors used are consistent with a relatively small number of important TCM precursor structures based upon 1,3-dicarbonyls or 1,3-diphenols.

  20. Predictive model for ice formation on superhydrophobic surfaces.

    PubMed

    Bahadur, Vaibhav; Mishchenko, Lidiya; Hatton, Benjamin; Taylor, J Ashley; Aizenberg, Joanna; Krupenkin, Tom

    2011-12-01

    The prevention and control of ice accumulation has important applications in aviation, building construction, and energy conversion devices. One area of active research concerns the use of superhydrophobic surfaces for preventing ice formation. The present work develops a physics-based modeling framework to predict ice formation on cooled superhydrophobic surfaces resulting from the impact of supercooled water droplets. This modeling approach analyzes the multiple phenomena influencing ice formation on superhydrophobic surfaces through the development of submodels describing droplet impact dynamics, heat transfer, and heterogeneous ice nucleation. These models are then integrated together to achieve a comprehensive understanding of ice formation upon impact of liquid droplets at freezing conditions. The accuracy of this model is validated by its successful prediction of the experimental findings that demonstrate that superhydrophobic surfaces can fully prevent the freezing of impacting water droplets down to surface temperatures of as low as -20 to -25 °C. The model can be used to study the influence of surface morphology, surface chemistry, and fluid and thermal properties on dynamic ice formation and identify parameters critical to achieving icephobic surfaces. The framework of the present work is the first detailed modeling tool developed for the design and analysis of surfaces for various ice prevention/reduction strategies. PMID:21899285

  1. Mnemonic networks in the hippocampal formation: from spatial maps to temporal and conceptual codes.

    PubMed

    Milivojevic, Branka; Doeller, Christian F

    2013-11-01

    The hippocampal formation has been associated with a wide variety of functions including spatial navigation and planning, memory encoding and retrieval, relational processing, novelty detection, and imagination. These functions are dissimilar in terms of their behavioral consequences and modality of representation. Consequently, theoretical standpoints have focused on explaining the role of the hippocampal formation in terms of either its spatial or nonspatial functions. Contrary to this dichotomy, we propose that it is essential to look beyond these traditional boundaries between mnemonic and spatial functions and focus instead on the processes that these functions have in common. In this framework, we use electrophysiology data from the spatial domain to predict effects on the systems level, both in spatial and nonspatial domains. We initially outline the results of studies that have used findings from spatial navigation in rodents to predict the patterns of brain activity observable in people who are exploring virtual environments. We discuss how certain properties of space-defining neurons enable space to be represented as a mental map of interconnected locations, which are expressed at multiple spatial scales in separate modules in the hippocampal formation. We then suggest that memories are also organized in networks, characterized by mnemonic and temporal hierarchies. We finish by discussing how virtual-reality techniques can be used to create novel lifelike episodes allowing us to look at episodic memory processes while multivariate analysis tools can be used to explore the organizational structure of mnemonic networks.

  2. Pre-stimulus thalamic theta power predicts human memory formation.

    PubMed

    Sweeney-Reed, Catherine M; Zaehle, Tino; Voges, Jürgen; Schmitt, Friedhelm C; Buentjen, Lars; Kopitzki, Klaus; Richardson-Klavehn, Alan; Hinrichs, Hermann; Heinze, Hans-Jochen; Knight, Robert T; Rugg, Michael D

    2016-09-01

    Pre-stimulus theta (4-8Hz) power in the hippocampus and neocortex predicts whether a memory for a subsequent event will be formed. Anatomical studies reveal thalamus-hippocampal connectivity, and lesion, neuroimaging, and electrophysiological studies show that memory processing involves the dorsomedial (DMTN) and anterior thalamic nuclei (ATN). The small size and deep location of these nuclei have limited real-time study of their activity, however, and it is unknown whether pre-stimulus theta power predictive of successful memory formation is also found in these subcortical structures. We recorded human electrophysiological data from the DMTN and ATN of 7 patients receiving deep brain stimulation for refractory epilepsy. We found that greater pre-stimulus theta power in the right DMTN was associated with successful memory encoding, predicting both behavioral outcome and post-stimulus correlates of successful memory formation. In particular, significant correlations were observed between right DMTN theta power and both frontal theta and right ATN gamma (32-50Hz) phase alignment, and frontal-ATN theta-gamma cross-frequency coupling. We draw the following primary conclusions. Our results provide direct electrophysiological evidence in humans of a role for the DMTN as well as the ATN in memory formation. Furthermore, prediction of subsequent memory performance by pre-stimulus thalamic oscillations provides evidence that post-stimulus differences in thalamic activity that index successful and unsuccessful encoding reflect brain processes specifically underpinning memory formation. Finally, the findings broaden the understanding of brain states that facilitate memory encoding to include subcortical as well as cortical structures. PMID:27208861

  3. Geologic Mapping of the Medusae Fossae Formation, Mars, and the Northern Lowland Plains, Venus

    NASA Technical Reports Server (NTRS)

    Zimbelman, J. R.

    2010-01-01

    This report summarizes the status of mapping projects supported by NASA grant NNX07AP42G, through the Planetary Geology and Geophysics (PGG) program. The PGG grant is focused on 1:2M-scale mapping of portions of the Medusae Fossae Formation (MFF) on Mars. Also described below is the current status of two Venus geologic maps, generated under an earlier PGG mapping grant.

  4. Geologic Mapping of the Medusae Fossae Formation on Mars and the Northern Lowland Plains of Venus

    NASA Technical Reports Server (NTRS)

    Zimbelman, J. R.

    2009-01-01

    This report summarizes the status of mapping projects supported by NASA grant NNX07AP42G, through the Planetary Geology and Geophysics (PGG) program. The PGG grant is focused on 1:2M-scale mapping of portions of the Medusae Fossae Formation (MFF) on Mars. Also described below is the current status of two Venus geo-logic maps, generated under an earlier PGG mapping grant.

  5. Prediction of Peptide and Protein Propensity for Amyloid Formation.

    PubMed

    Família, Carlos; Dennison, Sarah R; Quintas, Alexandre; Phoenix, David A

    2015-01-01

    Understanding which peptides and proteins have the potential to undergo amyloid formation and what driving forces are responsible for amyloid-like fiber formation and stabilization remains limited. This is mainly because proteins that can undergo structural changes, which lead to amyloid formation, are quite diverse and share no obvious sequence or structural homology, despite the structural similarity found in the fibrils. To address these issues, a novel approach based on recursive feature selection and feed-forward neural networks was undertaken to identify key features highly correlated with the self-assembly problem. This approach allowed the identification of seven physicochemical and biochemical properties of the amino acids highly associated with the self-assembly of peptides and proteins into amyloid-like fibrils (normalized frequency of β-sheet, normalized frequency of β-sheet from LG, weights for β-sheet at the window position of 1, isoelectric point, atom-based hydrophobic moment, helix termination parameter at position j+1 and ΔG° values for peptides extrapolated in 0 M urea). Moreover, these features enabled the development of a new predictor (available at http://cran.r-project.org/web/packages/appnn/index.html) capable of accurately and reliably predicting the amyloidogenic propensity from the polypeptide sequence alone with a prediction accuracy of 84.9 % against an external validation dataset of sequences with experimental in vitro, evidence of amyloid formation. PMID:26241652

  6. Prediction of Peptide and Protein Propensity for Amyloid Formation.

    PubMed

    Família, Carlos; Dennison, Sarah R; Quintas, Alexandre; Phoenix, David A

    2015-01-01

    Understanding which peptides and proteins have the potential to undergo amyloid formation and what driving forces are responsible for amyloid-like fiber formation and stabilization remains limited. This is mainly because proteins that can undergo structural changes, which lead to amyloid formation, are quite diverse and share no obvious sequence or structural homology, despite the structural similarity found in the fibrils. To address these issues, a novel approach based on recursive feature selection and feed-forward neural networks was undertaken to identify key features highly correlated with the self-assembly problem. This approach allowed the identification of seven physicochemical and biochemical properties of the amino acids highly associated with the self-assembly of peptides and proteins into amyloid-like fibrils (normalized frequency of β-sheet, normalized frequency of β-sheet from LG, weights for β-sheet at the window position of 1, isoelectric point, atom-based hydrophobic moment, helix termination parameter at position j+1 and ΔG° values for peptides extrapolated in 0 M urea). Moreover, these features enabled the development of a new predictor (available at http://cran.r-project.org/web/packages/appnn/index.html) capable of accurately and reliably predicting the amyloidogenic propensity from the polypeptide sequence alone with a prediction accuracy of 84.9 % against an external validation dataset of sequences with experimental in vitro, evidence of amyloid formation.

  7. Ensemble Prediction of Flood Maps Under Uncertain Conditions

    NASA Astrophysics Data System (ADS)

    Pedrozo-Acuña, A.; Rodríguez-Rincón, J. P.; Brena-Naranjo, J. A. A.

    2014-12-01

    Hydro-meteorological hazards can have cascading effects and far-reaching implications on water security, with socio-economic and environmental consequences. Worldwide the magnitude of recent floods highlight the necessity to generate a better understanding on their causes and associated risk. An improved flood risk strategy should incorporate the communication of uncertain research results to decision-makers. Therefore, it is of paramount importance to generate a robust framework that enables its quantification. The purpose of this study is to investigate the propagation of meteorological uncertainty within a cascade modelling approach to flood mapping. The methodology is comprised of a Numerical Weather Prediction Model (NWP), a distributed rainfall-runoff model and a standard 2D hydrodynamic model. The cascade of models is used to reproduce an extreme flood event that took place in Southern Mexico, during September 2013. The event is selected as high quality field data (e.g. LiDAR; rain gauges) and satellite imagery are available. Uncertainty in the meteorological model (Weather Research and Forecasting model) is evaluated through the use of a multi-physics ensemble technique, which considers twelve parameterisation schemes to determine a given precipitation. The resulting precipitation fields are used as input in a distributed hydrological model, enabling the determination of different hydrographs associated to this event. Lastly, by means of a standard 2D hydrodynamic model, resulting hydrographs are used as forcing conditions to study the propagation of the meteorological uncertainty to an estimated flooded area. Results show the utility of the selected modelling approach to investigate error propagation within a cascade of models. Moreover, the error associated to the determination of the runoff, is showed to be lower than that obtained in the precipitation estimation suggesting that uncertainty do not necessarily increase within a model cascade.

  8. Structural mapping: how to study the genetic architecture of a phenotypic trait through its formation mechanism.

    PubMed

    Tong, Chunfa; Shen, Lianying; Lv, Yafei; Wang, Zhong; Wang, Xiaoling; Feng, Sisi; Li, Xin; Sui, Yihan; Pang, Xiaoming; Wu, Rongling

    2014-01-01

    Traditional approaches for genetic mapping are to simply associate the genotypes of a quantitative trait locus (QTL) with the phenotypic variation of a complex trait. A more mechanistic strategy has emerged to dissect the trait phenotype into its structural components and map specific QTLs that control the mechanistic and structural formation of a complex trait. We describe and assess such a strategy, called structural mapping, by integrating the internal structural basis of trait formation into a QTL mapping framework. Electrical impedance spectroscopy (EIS) has been instrumental for describing the structural components of a phenotypic trait and their interactions. By building robust mathematical models on circuit EIS data and embedding these models within a mixture model-based likelihood for QTL mapping, structural mapping implements the EM algorithm to obtain maximum likelihood estimates of QTL genotype-specific EIS parameters. The uniqueness of structural mapping is to make it possible to test a number of hypotheses about the pattern of the genetic control of structural components. We validated structural mapping by analyzing an EIS data collected for QTL mapping of frost hardiness in a controlled cross of jujube trees. The statistical properties of parameter estimates were examined by simulation studies. Structural mapping can be a powerful alternative for genetic mapping of complex traits by taking account into the biological and physical mechanisms underlying their formation.

  9. POSTERIOR PREDICTIVE MODEL CHECKS FOR DISEASE MAPPING MODELS. (R827257)

    EPA Science Inventory

    Disease incidence or disease mortality rates for small areas are often displayed on maps. Maps of raw rates, disease counts divided by the total population at risk, have been criticized as unreliable due to non-constant variance associated with heterogeneity in base population si...

  10. Predicting Behavior from Cognitive Cause Maps of a Work Setting.

    ERIC Educational Resources Information Center

    Komocar, John

    Cognitive cause maps permit a topological investigation of the complexity of organizational events and behaviors. Because cognitive cause maps are believed to be ordered according to a givens-means-ends schema, they contain information about an individual's motivation structure. In a work setting an individual engages in several different acts.…

  11. Active plasma source formation in the MAP diode

    SciTech Connect

    Lamppa, K.P.; Stinnett, R.W.; Renk, T.J.

    1995-07-01

    The Ion Beam Surface Treatment (IBEST) program is exploring using ion beams to treat the surface of a wide variety of materials. These experiments have shown that improved corrosion resistance, surface hardening, grain size modification, polishing and surface cleaning can all be achieved using a pulsed 0.4-0.8 MeV ion beam delivering 1-10 J/cm{sup 2}. The Magnetically-confined Anode Plasma (MAP) diode, developed at Cornell University, produces an active plasma which can be used to treat the surfaces of materials. The diode consists of a fast puff valve as the source of gas to produce the desired ions and two capacitively driven B-fields. A slow magnetic field is used for electron insulation and a fast field is used to both ionize the puffed gas and to position the plasma in the proper spatial location in the anode prior to the accelerator pulse. The relative timing between subsystems is an important factor in the effective production of the active plasma source for the MAP diode system. The MAP diode has been characterized using a Langmuir probe to measure plasma arrival times at the anode annulus for hydrogen gas. This data was then used to determine the optimum operating point for the MAP diode on RHEPP-1 accelerator shots. Operation of the MAP diode system to produce an ion beam of 500 kV, 12 kA with 40% efficiency (measured at the diode) has been demonstrated.

  12. Electromagnetic wave method for mapping subterranean earth formations

    DOEpatents

    Shuck, Lowell Z.; Fasching, George E.; Balanis, Constantine A.

    1977-01-01

    The present invention is directed to a method for remotely mapping subterranean coal beds prior to and during in situ gasification operations. This method is achieved by emplacing highly directional electromagnetic wave transmitters and receivers in bore holes penetrating the coal beds and then mapping the anomalies surrounding each bore hole by selectively rotating and vertically displacing the directional transmitter in a transmitting mode within the bore hole, and thereafter, initiating the gasification of the coal at bore holes separate from those containing the transmitters and receivers and then utilizing the latter for monitoring the burn front as it progresses toward the transmitters and receivers.

  13. Predictive lithological mapping of Canada's North using Random Forest classification applied to geophysical and geochemical data

    NASA Astrophysics Data System (ADS)

    Harris, J. R.; Grunsky, E. C.

    2015-07-01

    A recent method for mapping lithology which involves the Random Forest (RF) machine classification algorithm is evaluated. Random Forests, a supervised classifier, requires training data representative of each lithology to produce a predictive or classified map. We use two training strategies, one based on the location of lake sediment geochemical samples where the rock type is recorded from a legacy geology map at each sample station and the second strategy is based on lithology recorded from field stations derived from reconnaissance field mapping. We apply the classification to interpolated major and minor lake sediment geochemical data as well as airborne total field magnetic and gamma ray spectrometer data. Using this method we produce predictions of the lithology of a large section of the Hearne Archean - Paleoproterozoic tectonic domain, in northern Canada. The results indicate that meaningful predictive lithologic maps can be produced using RF classification for both training strategies. The best results were achieved when all data were used; however, the geochemical and gamma ray data were the strongest predictors of the various lithologies. The maps generated from this research can be used to compliment field mapping activities by focusing field work on areas where the predicted geology and legacy geology do not match and as first order geological maps in poorly mapped areas.

  14. Multiscale Model of Mycobacterium tuberculosis Infection Maps Metabolite and Gene Perturbations to Granuloma Sterilization Predictions

    PubMed Central

    Pienaar, Elsje; Matern, William M.; Linderman, Jennifer J.

    2016-01-01

    Granulomas are a hallmark of tuberculosis. Inside granulomas, the pathogen Mycobacterium tuberculosis may enter a metabolically inactive state that is less susceptible to antibiotics. Understanding M. tuberculosis metabolism within granulomas could contribute to reducing the lengthy treatment required for tuberculosis and provide additional targets for new drugs. Two key adaptations of M. tuberculosis are a nonreplicating phenotype and accumulation of lipid inclusions in response to hypoxic conditions. To explore how these adaptations influence granuloma-scale outcomes in vivo, we present a multiscale in silico model of granuloma formation in tuberculosis. The model comprises host immunity, M. tuberculosis metabolism, M. tuberculosis growth adaptation to hypoxia, and nutrient diffusion. We calibrated our model to in vivo data from nonhuman primates and rabbits and apply the model to predict M. tuberculosis population dynamics and heterogeneity within granulomas. We found that bacterial populations are highly dynamic throughout infection in response to changing oxygen levels and host immunity pressures. Our results indicate that a nonreplicating phenotype, but not lipid inclusion formation, is important for long-term M. tuberculosis survival in granulomas. We used virtual M. tuberculosis knockouts to predict the impact of both metabolic enzyme inhibitors and metabolic pathways exploited to overcome inhibition. Results indicate that knockouts whose growth rates are below ∼66% of the wild-type growth rate in a culture medium featuring lipid as the only carbon source are unable to sustain infections in granulomas. By mapping metabolite- and gene-scale perturbations to granuloma-scale outcomes and predicting mechanisms of sterilization, our method provides a powerful tool for hypothesis testing and guiding experimental searches for novel antituberculosis interventions. PMID:26975995

  15. Applications systems verification and transfer project. Volume 8: Satellite snow mapping and runoff prediction handbook

    NASA Technical Reports Server (NTRS)

    Bowley, C. J.; Barnes, J. C.; Rango, A.

    1981-01-01

    The purpose of the handbook is to update the various snowcover interpretation techniques, document the snow mapping techniques used in the various ASVT study areas, and describe the ways snowcover data have been applied to runoff prediction. Through documentation in handbook form, the methodology developed in the Snow Mapping ASVT can be applied to other areas.

  16. Improving RNA secondary structure prediction with structure mapping data.

    PubMed

    Sloma, Michael F; Mathews, David H

    2015-01-01

    Methods to probe RNA secondary structure, such as small molecule modifying agents, secondary structure-specific nucleases, inline probing, and SHAPE chemistry, are widely used to study the structure of functional RNA. Computational secondary structure prediction programs can incorporate probing data to predict structure with high accuracy. In this chapter, an overview of current methods for probing RNA secondary structure is provided, including modern high-throughput methods. Methods for guiding secondary structure prediction algorithms using these data are explained, and best practices for using these data are provided. This chapter concludes by listing a number of open questions about how to best use probing data, and what these data can provide.

  17. A thermodynamic model for predicting wax formation in crude oils

    SciTech Connect

    Hansen, J.H.; Fredenslund, A.; Pedersen, K.S.; Renningsen, H.P.

    1988-12-01

    Most crude oils contain high molecular weight components, which at low temperatures may precipitate as a wax phase. This may cause plugging of pipes and numerous other problems. This paper presents a solid-liquid equilibrium based model for the description of wax formation. The model for the Gibbs energy contains a contribution based on Flory's theory of multicomponent polymer solutions and a contribution from a metastable subcooled state which oil mixtures may attain. The latter is formulated in terms of the surface tension of the wax phase. Experimental wax appearance points (temperatures), WAP's, are reported for 17 different stabilized North Sea crude oils. The values predicted by the new model are in very good agreement with the experimental WAP's.

  18. Concept Mapping the Client's Perspective on Counseling Alliance Formation

    ERIC Educational Resources Information Center

    Bedi, Robinder P.

    2006-01-01

    The purpose of the present study was to identify, categorize, and model clients' understanding of early counseling alliance formation factors. Forty participants who had received counseling services were interviewed and asked about what observable behaviors and verbalizations they thought had helped establish the alliance with their counselor.…

  19. CO mapping of the Orion molecular cloud: The influence of star formation on cloud structure

    NASA Technical Reports Server (NTRS)

    Schloerb, F. P.; Snell, R. L.; Goldsmith, P. F.; Morgan, J. A.

    1986-01-01

    Regions of massive star formation have long been believed to have a profound influence on the structure of their surrounding molecular clouds. The ways in which massive star formation has altered the structure and kinematics of the Orion Molecular Cloud are discussed. The data to be discussed consists of a large scale map of the CO J=1-0 emission from approximately 3 square degrees of OMC-1. During 1985, the Five College Radio Astronomy Observatory 14M antenna was used to map a 2 deg x 1 deg region centered on alpha(1950) = 5(h)33(m)00(s) delta(1950) = -5 deg 30 min. The region mapped in 1985 covers the well known HII regions M42, M43, and NGC1977, and the CO map contains abundant evidence of the interaction between these regions and the molecular cloud. Indeed, the global structure of the cloud appears to have been strongly influenced by the continuous formation of massive stars within the cloud. Individual instances of some of these features are discussed. There appear to be two classes of features which are indicative of this interaction: CO bright rims and CO holes. During 1986, we have undertaken further mapping of OMC-1 to the south of the region covered by the 1985 map. This portion of the cloud contains significant regions of star formation, but O star formation has not occured and large HII regions have not developed to alter the appearance of the cloud. A detailed map of this region is thus an opportunity to view the structure of the molecular cloud before it has been altered by massive star formation. Preliminary analysis of data obtained in this region suggests that the structure and kinematics of the southern portion of the Orion cloud are indeed dramatically different from those of the region previously mapped. Comparison of the two regions thus supports models of the development of structure in molecular clouds through interaction with the HII regions formed within them.

  20. Predictive lymphatic mapping: a method for mapping lymphatic channels in patients with advanced unilateral lymphedema using indocyanine green lymphography.

    PubMed

    Mihara, Makoto; Seki, Yukio; Hara, Hisako; Iida, Takuya; Oka, Aiko; Kikuchi, Kazuki; Narushima, Mitsunaga; Haragi, Makiko; Furniss, Dominic; Hin-Lun, Lawrence; Mitsui, Kito; Murai, Noriyuki; Koshima, Isao

    2014-01-01

    In severe lymphedema, indocyanine green lymphography cannot be used to map lymphatic channels before lymphaticovenular anastomosis (LVA) because linear lymphatics cannot be detected in a severely affected leg. Here, we describe a new method, which we refer to as predictive lymphatic mapping, to predict the location of lymphatics for anastomosis in unilateral lymphedema, thereby improving surgical accuracy and efficiency. The approach consists of marking anatomical landmarks and joining selected landmarks with fixed lines. The distance from these fixed lines to lymphatic channels mapped by indocyanine green lymphography in the unaffected leg is then measured, scaled up based on the difference in circumference between the legs, and transposed to the affected leg. To date, we have used this method in 5 cases of unilateral or asymmetric lymphedema of the lower extremities. In no cases have we failed to find a lymphatic channel suitable for LVA within a 2-cm incision. These results suggest that predictive lymphatic mapping is a useful additional tool for surgeons performing LVA under local anesthesia, which will help to improve the accuracy of incisions and the efficiency of surgery.

  1. Microstructure of polycrystalline PBTTT films: domain mapping and structure formation.

    PubMed

    Schuettfort, Torben; Watts, Benjamin; Thomsen, Lars; Lee, Mijung; Sirringhaus, Henning; McNeill, Christopher R

    2012-02-28

    We utilize near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and scanning transmission X-ray microscopy (STXM) to study the microstructure and domain structure of polycrystalline films of the semiconducting polymer poly(2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT). Total electron yield NEXAFS spectroscopy is used to examine the surface structure of the first 1-2 molecular layers, while bulk-sensitive STXM is used to produce maps of domain orientation and order sampled through the entire film thickness. We study different phases of PBTTT including as-cast, terraced and nanoribbon morphologies produced via spin-coating as well as aligned films of as-cast and nanoribbon morphologies produced by zone-casting. For the terraced morphology, domains are observed that are larger than the size of the terraced surface features, and the calculated degree of order is reduced compared to the nanoribbon morphology. For zone-cast films, we find that, although little optical anisotropy is observed in the bulk of as-cast films, a high degree of surface structural anisotropy is observed with NEXAFS spectroscopy, similar to what is observed in annealed nanoribbon films. This observation indicates that the aligned surface structure in unannealed zone-cast films templates the bulk ordering of the aligned nanoribbon phase. STXM domain mapping of aligned nanoribbon films reveals elongated, micrometer-wide domains with each domain misoriented with respect to its neighbor by up to 45°, but with broad domain boundaries. Within each nanoribbon domain, a high degree of X-ray dichroism is observed, indicating correlated ordering throughout the bulk of the film.

  2. Improving predictive mapping of deep-water habitats: Considering multiple model outputs and ensemble techniques

    NASA Astrophysics Data System (ADS)

    Robert, Katleen; Jones, Daniel O. B.; Roberts, J. Murray; Huvenne, Veerle A. I.

    2016-07-01

    In the deep sea, biological data are often sparse; hence models capturing relationships between observed fauna and environmental variables (acquired via acoustic mapping techniques) are often used to produce full coverage species assemblage maps. Many statistical modelling techniques are being developed, but there remains a need to determine the most appropriate mapping techniques. Predictive habitat modelling approaches (redundancy analysis, maximum entropy and random forest) were applied to a heterogeneous section of seabed on Rockall Bank, NE Atlantic, for which landscape indices describing the spatial arrangement of habitat patches were calculated. The predictive maps were based on remotely operated vehicle (ROV) imagery transects high-resolution autonomous underwater vehicle (AUV) sidescan backscatter maps. Area under the curve (AUC) and accuracy indicated similar performances for the three models tested, but performance varied by species assemblage, with the transitional species assemblage showing the weakest predictive performances. Spatial predictions of habitat suitability differed between statistical approaches, but niche similarity metrics showed redundancy analysis and random forest predictions to be most similar. As one statistical technique could not be found to outperform the others when all assemblages were considered, ensemble mapping techniques, where the outputs of many models are combined, were applied. They showed higher accuracy than any single model. Different statistical approaches for predictive habitat modelling possess varied strengths and weaknesses and by examining the outputs of a range of modelling techniques and their differences, more robust predictions, with better described variation and areas of uncertainties, can be achieved. As improvements to prediction outputs can be achieved without additional costly data collection, ensemble mapping approaches have clear value for spatial management.

  3. Stochastic interaction between neural activity and molecular cues in the formation of topographic maps

    PubMed Central

    Owens, Melinda T.; Feldheim, David A.; Stryker, Michael P.; Triplett, Jason W.

    2015-01-01

    SUMMARY Topographic maps in visual processing areas maintain the spatial order of the visual world. Molecular cues and neuronal activity both play critical roles in map formation, but their interaction remains unclear. Here, we demonstrate that when molecular- and activity-dependent cues are rendered nearly equal in force, they drive topographic mapping stochastically. The functional and anatomical representation of azimuth in the superior colliculus of heterozygous Islet2-EphA3 knock-in (Isl2EphA3/+) mice is variable: maps may be single, duplicated, or a combination of the two. This heterogeneity is not due to genetic differences, since map organizations in individual mutant animals often differ between colliculi. Disruption of spontaneous waves of retinal activity resulted in uniform map organization in Isl2EphA3/+ mice, demonstrating that correlated spontaneous activity is required for map heterogeneity. Computational modeling replicates this heterogeneity, revealing that molecular- and activity-dependent forces interact simultaneously and stochastically during topographic map formation. PMID:26402608

  4. Gamma Synchronization Influences Map Formation Time in a Topological Model of Spatial Learning.

    PubMed

    Basso, Edward; Arai, Mamiko; Dabaghian, Yuri

    2016-09-01

    The mammalian hippocampus plays a crucial role in producing a cognitive map of space-an internalized representation of the animal's environment. We have previously shown that it is possible to model this map formation using a topological framework, in which information about the environment is transmitted through the temporal organization of neuronal spiking activity, particularly those occasions in which the firing of different place cells overlaps. In this paper, we discuss how gamma rhythm, one of the main components of the extracellular electrical field potential affects the efficiency of place cell map formation. Using methods of algebraic topology and the maximal entropy principle, we demonstrate that gamma modulation synchronizes the spiking of dynamical cell assemblies, which enables learning a spatial map at faster timescales. PMID:27636199

  5. Gamma Synchronization Influences Map Formation Time in a Topological Model of Spatial Learning

    PubMed Central

    Basso, Edward; Arai, Mamiko; Dabaghian, Yuri

    2016-01-01

    The mammalian hippocampus plays a crucial role in producing a cognitive map of space—an internalized representation of the animal’s environment. We have previously shown that it is possible to model this map formation using a topological framework, in which information about the environment is transmitted through the temporal organization of neuronal spiking activity, particularly those occasions in which the firing of different place cells overlaps. In this paper, we discuss how gamma rhythm, one of the main components of the extracellular electrical field potential affects the efficiency of place cell map formation. Using methods of algebraic topology and the maximal entropy principle, we demonstrate that gamma modulation synchronizes the spiking of dynamical cell assemblies, which enables learning a spatial map at faster timescales. PMID:27636199

  6. Predictive map of geoelectric sections of North China and its application for the radiofields calculations

    NASA Astrophysics Data System (ADS)

    Bashkuev, Yu. B.; Angarkhaeva, L. K.; Advokatov, V. R.; Dembelov, M. G.; Dorzhiev, V. S.; Ivoilov, Yu. A.

    2015-11-01

    Predictive map of geoelectric sections of the North China on a scale of 1 : 2 500 000, necessary for calculation of propagation of VLF-MF radiowaves, is constructed. Taking into account the layered structure of the underlying medium, this map is capable of increasing the accuracy of electromagnetic field calculations by 1.5-3 times as compared to the Morgan-Maxwell map. The methodology of the geoelectric mapping is described. The studies of electrical properties of layered media by combined radio and geophysical methods in a variety of natural and geological conditions, and the proposed method of geoelectric mapping have resulted in the construction of a new generation of maps showing the electrical properties of the underlying medium that account for the layered structure of the crust and have no analogues in the world.

  7. Vector Topographic Map Data over the BOREAS NSA and SSA in SIF Format

    NASA Technical Reports Server (NTRS)

    Knapp, David; Nickeson, Jaime; Hall, Forrest G. (Editor)

    2000-01-01

    This data set contains vector contours and other features of individual topographic map sheets from the National Topographic Series (NTS). The map sheet files were received in Standard Interchange Format (SIF) and cover the BOReal Ecosystem-Atmosphere Study (BOREAS) Northern Study Area (NSA) and Southern Study Area (SSA) at scales of 1:50,000 and 1:250,000. The individual files are stored in compressed Unix tar archives.

  8. Quantitative assessment of computational models for retinotopic map formation

    PubMed Central

    Sterratt, David C; Cutts, Catherine S; Willshaw, David J; Eglen, Stephen J

    2014-01-01

    ABSTRACT Molecular and activity‐based cues acting together are thought to guide retinal axons to their terminal sites in vertebrate optic tectum or superior colliculus (SC) to form an ordered map of connections. The details of mechanisms involved, and the degree to which they might interact, are still not well understood. We have developed a framework within which existing computational models can be assessed in an unbiased and quantitative manner against a set of experimental data curated from the mouse retinocollicular system. Our framework facilitates comparison between models, testing new models against known phenotypes and simulating new phenotypes in existing models. We have used this framework to assess four representative models that combine Eph/ephrin gradients and/or activity‐based mechanisms and competition. Two of the models were updated from their original form to fit into our framework. The models were tested against five different phenotypes: wild type, Isl2‐EphA3 ki/ki, Isl2‐EphA3 ki/+, ephrin‐A2,A3,A5 triple knock‐out (TKO), and Math5 −/− (Atoh7). Two models successfully reproduced the extent of the Math5 −/− anteromedial projection, but only one of those could account for the collapse point in Isl2‐EphA3 ki/+. The models needed a weak anteroposterior gradient in the SC to reproduce the residual order in the ephrin‐A2,A3,A5 TKO phenotype, suggesting either an incomplete knock‐out or the presence of another guidance molecule. Our article demonstrates the importance of testing retinotopic models against as full a range of phenotypes as possible, and we have made available MATLAB software, we wrote to facilitate this process. © 2014 Wiley Periodicals, Inc. Develop Neurobiol 75: 641–666, 2015 PMID:25367067

  9. Traction force dynamics predict gap formation in activated endothelium.

    PubMed

    Valent, Erik T; van Nieuw Amerongen, Geerten P; van Hinsbergh, Victor W M; Hordijk, Peter L

    2016-09-10

    In many pathological conditions the endothelium becomes activated and dysfunctional, resulting in hyperpermeability and plasma leakage. No specific therapies are available yet to control endothelial barrier function, which is regulated by inter-endothelial junctions and the generation of acto-myosin-based contractile forces in the context of cell-cell and cell-matrix interactions. However, the spatiotemporal distribution and stimulus-induced reorganization of these integral forces remain largely unknown. Traction force microscopy of human endothelial monolayers was used to visualize contractile forces in resting cells and during thrombin-induced hyperpermeability. Simultaneously, information about endothelial monolayer integrity, adherens junctions and cytoskeletal proteins (F-actin) were captured. This revealed a heterogeneous distribution of traction forces, with nuclear areas showing lower and cell-cell junctions higher traction forces than the whole-monolayer average. Moreover, junctional forces were asymmetrically distributed among neighboring cells. Force vector orientation analysis showed a good correlation with the alignment of F-actin and revealed contractile forces in newly formed filopodia and lamellipodia-like protrusions within the monolayer. Finally, unstable areas, showing high force fluctuations within the monolayer were prone to form inter-endothelial gaps upon stimulation with thrombin. To conclude, contractile traction forces are heterogeneously distributed within endothelial monolayers and force instability, rather than force magnitude, predicts the stimulus-induced formation of intercellular gaps. PMID:27498166

  10. Formation of temporal-feature maps by axonal propagation of synaptic learning.

    PubMed

    Kempter, R; Leibold, C; Wagner, H; van Hemmen, J L

    2001-03-27

    Computational maps are of central importance to a neuronal representation of the outside world. In a map, neighboring neurons respond to similar sensory features. A well studied example is the computational map of interaural time differences (ITDs), which is essential to sound localization in a variety of species and allows resolution of ITDs of the order of 10 micros. Nevertheless, it is unclear how such an orderly representation of temporal features arises. We address this problem by modeling the ontogenetic development of an ITD map in the laminar nucleus of the barn owl. We show how the owl's ITD map can emerge from a combined action of homosynaptic spike-based Hebbian learning and its propagation along the presynaptic axon. In spike-based Hebbian learning, synaptic strengths are modified according to the timing of pre- and postsynaptic action potentials. In unspecific axonal learning, a synapse's modification gives rise to a factor that propagates along the presynaptic axon and affects the properties of synapses at neighboring neurons. Our results indicate that both Hebbian learning and its presynaptic propagation are necessary for map formation in the laminar nucleus, but the latter can be orders of magnitude weaker than the former. We argue that the algorithm is important for the formation of computational maps, when, in particular, time plays a key role. PMID:11274439

  11. Can Self-Organizing Maps Accurately Predict Photometric Redshifts?

    NASA Astrophysics Data System (ADS)

    Way, M. J.; Klose, C. D.

    2012-03-01

    We present an unsupervised machine-learning approach that can be employed for estimating photometric redshifts. The proposed method is based on a vector quantization called the self-organizing-map (SOM) approach. A variety of photometrically derived input values were utilized from the Sloan Digital Sky Survey's main galaxy sample, luminous red galaxy, and quasar samples, along with the PHAT0 data set from the Photo-z Accuracy Testing project. Regression results obtained with this new approach were evaluated in terms of root-mean-square error (RMSE) to estimate the accuracy of the photometric redshift estimates. The results demonstrate competitive RMSE and outlier percentages when compared with several other popular approaches, such as artificial neural networks and Gaussian process regression. SOM RMSE results (using Δz = zphot - zspec) are 0.023 for the main galaxy sample, 0.027 for the luminous red galaxy sample, 0.418 for quasars, and 0.022 for PHAT0 synthetic data. The results demonstrate that there are nonunique solutions for estimating SOM RMSEs. Further research is needed in order to find more robust estimation techniques using SOMs, but the results herein are a positive indication of their capabilities when compared with other well-known methods.

  12. Exploration of very high spatial resolution data for vegetation mapping using cartographic ontologies: Identifying life forms to mapping formations

    NASA Astrophysics Data System (ADS)

    Rodriguez-Gallegos, Hugo Benigno

    Vegetation mapping is often considered the process of identifying landscape patterns of individuals or clusters of species or life forms (LF). At the landscape scale, the larger pattern represented by individuals or clusters represents the conceptualization of "vegetation mapping" and can be used as a building block to describe an ecosystem. To represent these building blocks or LF a "common entity (CE)" concept is introduced to represent the components of Formations as described by the National Vegetation Classification (NVC) system. The NVC has established protocols to consistently represent plant communities and promote coordinated management, particularly across jurisdictional boundaries. However, it is not a universal standard and the methods of producing detailed maps of vegetation CE from very high spatial resolution (VHR) remote sensing data are important research questions. This research addressed how best to understand and represent plant cover in arid regions, the most effective methods of mapping vegetation cover using high spatial resolution data, how to assess the accuracy of these maps, and their value in establishing more standardized mapping protocols across ecosystems. Utilizing VHR products from the IKONOS and QuickBird sensors the study focused on the Coronado National Memorial and Chiricahua National Monument in Arizona and Los Ajos and Pinacate - Grand Desierto Biosphere Reserves in Mexico. Individual CE were semi-automatically mapped incorporating spectral, textural and geostatistical variables. The results were evaluated across sensors, study sites, and input variables. In addition, multiple methods of acquiring field data for accuracy assessment were evaluated and then an evaluation was made of a semi-automatic determination of Formation based on CE. The results of the study suggest consistency across study sites using the IKONOS data. A comparison between VHR products from the same place is feasible but sensor spectral differences may

  13. Mapping Genes that Predict Treatment Outcome in Admixed Populations

    PubMed Central

    Baye, Tesfaye M.; Wilke, Russell A.

    2010-01-01

    There is great interest in characterizing the genetic architecture underlying drug response. For many drugs, gene-based dosing models explain a considerable amount of the overall variation in treatment outcome. As such, prescription drug labels are increasingly being modified to contain pharmacogenetic information. Genetic data must, however, be interpreted within the context of relevant clinical covariates. Even the most predictive models improve with the addition of data related to biogeographical ancestry. The current review explores analytical strategies that leverage population structure to more fully characterize genetic determinants of outcome in large clinical practice-based cohorts. The success of this approach will depend upon several key factors: (1) the availability of outcome data from groups of admixed individuals (i.e., populations recombined over multiple generations), (2) a measurable difference in treatment outcome (i.e., efficacy and toxicity endpoints), and (3) a measurable difference in allele frequency between the ancestral populations. PMID:20921971

  14. Two States Mapping Based Time Series Neural Network Model for Compensation Prediction Residual Error

    NASA Astrophysics Data System (ADS)

    Jung, Insung; Koo, Lockjo; Wang, Gi-Nam

    2008-11-01

    The objective of this paper was to design a model of human bio signal data prediction system for decreasing of prediction error using two states mapping based time series neural network BP (back-propagation) model. Normally, a lot of the industry has been applied neural network model by training them in a supervised manner with the error back-propagation algorithm for time series prediction systems. However, it still has got a residual error between real value and prediction result. Therefore, we designed two states of neural network model for compensation residual error which is possible to use in the prevention of sudden death and metabolic syndrome disease such as hypertension disease and obesity. We determined that most of the simulation cases were satisfied by the two states mapping based time series prediction model. In particular, small sample size of times series were more accurate than the standard MLP model.

  15. Modified Mercalli Intensity Maps for the 1868 Hayward Earthquake Plotted in ShakeMap Format

    USGS Publications Warehouse

    Boatwright, John; Bundock, Howard

    2008-01-01

    To construct the Modified Mercalli Intensity (MMI) ShakeMap for the 1868 Hayward earthquake, we started with two sets of damage descriptions and felt reports. The first set of 100 sites was compiled by A.A. Bullock in the Lawson (1908) report on the 1906 San Francisco earthquake. The second set of 45 sites was compiled by Toppozada et al. (1981) from an extensive search of newspaper archives. We supplemented these two sets of reports with new observations from 30 sites using surveys of cemetery damage, reports of damage to historic adobe structures, pioneer narratives, and reports from newspapers that Toppozada et al. (1981) did not retrieve. The Lawson (1908) and Toppozada et al. (1981) compilations and our contributions are assembled in the Site List.

  16. Predicting environmental risk: A road map for the future.

    PubMed

    Jager, Tjalling

    2016-01-01

    Frameworks for environmental risk assessment (ERA) focus on comparing results from separate exposure and effect assessments. Exposure assessment generally relies on mechanistic fate models, whereas the effects assessment is anchored in standard test protocols and descriptive statistics. This discrepancy prevents a useful link between these two pillars of ERA, and jeopardizes the realism and efficacy of the entire process. Similar to exposure assessment, effects assessment requires a mechanistic approach to translate the output of fate models into predictions for impacts on populations and food webs. The aim of this study was to discuss (1) the central importance of the individual level, (2) different strategies of dealing with biological complexity, and (3) the role that toxicokinetic-toxicodynamic (TKTD) models, energy budgets, and molecular biology play in a mechanistic revision of the ERA framework. Consequently, an outline for a risk assessment paradigm was developed that incorporates a mechanistic effects assessment in a consistent manner, and a "roadmap for the future." Such a roadmap may play a critical role to eventually arrive at a more scientific and efficient ERA process, and needs to be used to shape our long-term research agendas. PMID:27484139

  17. Impervious cover mapping and runoff predictions in a Dallas watershed using Landsat TM

    SciTech Connect

    Singletary, K.L.; Morgan, K.M.; Busbey, A.B.; Newland, L.W. . Dept. of Geology)

    1993-02-01

    As urban development increases in metropolitan areas, the amount of impervious cover also increases and directly affects stormwater runoff volume. Techniques are needed by planning agencies to monitor urban changes and update flood maps. In this study, the six 30 meter resolution bands of Landsat TM were analyzed to determine which wavelength(s) could be used to map impervious cover in a watershed near Dallas. The resulting information was utilized in a runoff equation and compared to actual stormwater flow recorded at a U.S.G.S. gauge station. Accuracies of the image mapping and predicted runoff are presented.

  18. Formation of temporal-feature maps in the barn owl's auditory system

    NASA Astrophysics Data System (ADS)

    Kempter, Richard

    2000-03-01

    Computational maps are of central importance to the brain's representation of the outside world. The question of how maps are formed during ontogenetic development is a subject of intense research (Hubel & Wiesel, Proc R Soc B 198:1, 1977; Buonomano & Merzenich, Annu Rev Neurosci 21:149, 1998). The development in the primary visual cortex is in principle well explained compared to that in the auditory system, partly because the mechanisms underlying the formation of temporal-feature maps are hardly understood (Carr, Annu Rev Neurosci 16:223, 1993). Through a modelling study based on computer simulations in a system of spiking neurons a solution is offered to the problem of how a map of interaural time differences is set up in the nucleus laminaris of the barn owl, as a typical example. An array of neurons is able to represent interaural time differences in an orderly manner, viz., a map, if homosynaptic spike-based Hebbian learning (Gerstner et al, Nature 383:76, 1996; Kempter et al, Phys Rev E 59:4498, 1999) is combined with a presynaptic propagation of synaptic modifications (Fitzsimonds & Poo, Physiol Rev 78:143, 1998). The latter may be orders of magnitude weaker than the former. The algorithm is a key mechanism to the formation of temporal-feature maps on a submillisecond time scale.

  19. Map on predicted deposition of Cs-137 in Spanish soils from geostatistical analyses.

    PubMed

    Caro, A; Legarda, F; Romero, L; Herranz, M; Barrera, M; Valiño, F; Idoeta, R; Olondo, C

    2013-01-01

    The knowledge of the distribution of (137)Cs deposition over Spanish mainland soils along with the geographical, physical and morphological terrain information enable us to know the (137)Cs background content in soil. This could be useful as a tool in a hypothetical situation of an accident involving a radioactive discharge or in soil erosion studies. A Geographic Information System (GIS) would allow the gathering of all the mentioned information. In this work, gamma measurements of (137)Cs on 34 Spanish mainland soils, rainfall data taken from 778 weather stations, soil types and geographical and physical terrain information were input into a GIS. Geostatistical techniques were applied to interpolate values of (137)Cs activity at unsampled places, obtaining prediction maps of (137)Cs deposition. Up to now, geostatistical methods have been used to model spatial continuity of data. Through semivariance and cross-covariance functions the spatial correlation of such data can be studied and described. Ordinary and simple kriging techniques were carried out to map spatial patterns of (137)Cs deposition, and ordinary and simple co-kriging were used to improve the prediction map obtained through a second related variable: namely the rainfall. To choose the best prediction map of (137)Cs deposition, the spatial dependence of the variable, the correlation coefficient and the prediction errors were evaluated using the different models previously mentioned. The best result for (137)Cs deposition map was obtained when applying the co-kriging techniques.

  20. Concept Maps of Korean EFL Student Teachers' Autobiographical Reflections on Their Professional Identity Formation

    ERIC Educational Resources Information Center

    Lim, Hyun-Woo

    2011-01-01

    This study utilizes a concept mapping method to explore the underlying structure and dimensionality of Korean student teachers' autobiographical reflections on their professional identity formation. Participants consist of 90 students enrolled in bachelor's and master's degree programs in English teacher education. The study results imply core…

  1. Classical predictability and coarse-grained evolution of the quantum baker's map

    SciTech Connect

    Scherer, Artur; Soklakov, Andrei N.; Schack, Ruediger

    2006-06-15

    We investigate how classical predictability of the coarse-grained evolution of the quantum baker's map depends on the character of the coarse-graining. Our analysis extends earlier work by Brun and Hartle [Phys. Rev. D 60, 123503 (1999)] to the case of a chaotic map. To quantify predictability, we compare the rate of entropy increase for a family of coarse-grainings in the decoherent histories formalism. We find that the rate of entropy increase is dominated by the number of scales characterizing the coarse-graining.

  2. The digital geologic map of Colorado in ARC/INFO format, Part B. Common files

    USGS Publications Warehouse

    Green, Gregory N.

    1992-01-01

    This geologic map was prepared as a part of a study of digital methods and techniques as applied to complex geologic maps. The geologic map was digitized from the original scribe sheets used to prepare the published Geologic Map of Colorado (Tweto 1979). Consequently the digital version is at 1:500,000 scale using the Lambert Conformal Conic map projection parameters of the state base map. Stable base contact prints of the scribe sheets were scanned on a Tektronix 4991 digital scanner. The scanner automatically converts the scanned image to an ASCII vector format. These vectors were transferred to a VAX minicomputer, where they were then loaded into ARC/INFO. Each vector and polygon was given attributes derived from the original 1979 geologic map. This database was developed on a MicroVAX computer system using VAX V 5.4 nd ARC/INFO 5.0 software. UPDATE: April 1995, The update was done solely for the purpose of adding the abilitly to plot to an HP650c plotter. Two new ARC/INFO plot AMLs along with a lineset and shadeset for the HP650C design jet printer have been included. These new files are COLORADO.650, INDEX.650, TWETOLIN.E00 and TWETOSHD.E00. These files were created on a UNIX platform with ARC/INFO 6.1.2. Updated versions of INDEX.E00, CONTACT.E00, LINE.E00, DECO.E00 and BORDER.E00 files that included the newly defined HP650c items are also included. * Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Descriptors: The Digital Geologic Map of Colorado in ARC/INFO Format Open-File Report 92-050

  3. The digital geologic map of Colorado in ARC/INFO format, Part A. Documentation

    USGS Publications Warehouse

    Green, Gregory N.

    1992-01-01

    This geologic map was prepared as a part of a study of digital methods and techniques as applied to complex geologic maps. The geologic map was digitized from the original scribe sheets used to prepare the published Geologic Map of Colorado (Tweto 1979). Consequently the digital version is at 1:500,000 scale using the Lambert Conformal Conic map projection parameters of the state base map. Stable base contact prints of the scribe sheets were scanned on a Tektronix 4991 digital scanner. The scanner automatically converts the scanned image to an ASCII vector format. These vectors were transferred to a VAX minicomputer, where they were then loaded into ARC/INFO. Each vector and polygon was given attributes derived from the original 1979 geologic map. This database was developed on a MicroVAX computer system using VAX V 5.4 nd ARC/INFO 5.0 software. UPDATE: April 1995, The update was done solely for the purpose of adding the abilitly to plot to an HP650c plotter. Two new ARC/INFO plot AMLs along with a lineset and shadeset for the HP650C design jet printer have been included. These new files are COLORADO.650, INDEX.650, TWETOLIN.E00 and TWETOSHD.E00. These files were created on a UNIX platform with ARC/INFO 6.1.2. Updated versions of INDEX.E00, CONTACT.E00, LINE.E00, DECO.E00 and BORDER.E00 files that included the newly defined HP650c items are also included. * Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Descriptors: The Digital Geologic Map of Colorado in ARC/INFO Format Open-File Report 92-050

  4. The digital geologic map of Colorado in ARC/INFO format

    USGS Publications Warehouse

    Green, Gregory N.

    1992-01-01

    This geologic map was prepared as a part of a study of digital methods and techniques as applied to complex geologic maps. The geologic map was digitized from the original scribe sheets used to prepare the published Geologic Map of Colorado (Tweto 1979). Consequently the digital version is at 1:500,000 scale using the Lambert Conformal Conic map projection parameters of the state base map. Stable base contact prints of the scribe sheets were scanned on a Tektronix 4991 digital scanner. The scanner automatically converts the scanned image to an ASCII vector format. These vectors were transferred to a VAX minicomputer, where they were then loaded into ARC/INFO. Each vector and polygon was given attributes derived from the original 1979 geologic map. This database was developed on a MicroVAX computer system using VAX V 5.4 nd ARC/INFO 5.0 software. UPDATE: April 1995, The update was done solely for the purpose of adding the abilitly to plot to an HP650c plotter. Two new ARC/INFO plot AMLs along with a lineset and shadeset for the HP650C design jet printer have been included. These new files are COLORADO.650, INDEX.650, TWETOLIN.E00 and TWETOSHD.E00. These files were created on a UNIX platform with ARC/INFO 6.1.2. Updated versions of INDEX.E00, CONTACT.E00, LINE.E00, DECO.E00 and BORDER.E00 files that included the newly defined HP650c items are also included. * Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Descriptors: The Digital Geologic Map of Colorado in ARC/INFO Format Open-File Report 92-050

  5. Fostering ontology alignment sharing: a general-purpose RDF mapping format.

    PubMed

    Anguita, Alberto; Escrich, Ana; Maojo, Victor

    2013-01-01

    RDF has established in the last years as the language for describing, publishing and sharing biomedical resources. Following this trend, a great amount of RDF-based data sources, as well as ontologies, have appeared. Using a common language as RDF has provided a unified syntactic for sharing resources, but the semantics remain as the main cause of heterogeneity, hampering data integration and homogenization efforts. To overcome this issue, ontology alignment based solutions have been typically used. However, alignment information is usually codified using ad-hoc formats. In this paper, we present a general purpose ontology mapping format, totally independent from the homogenization approach to be applied. The format is accompanied with a Java API that offers mapping construction and parsing features, as well as some basic algorithms for applying it to data translation solutions.

  6. Dependence of Initial Value on Pattern Formation for a Logistic Coupled Map Lattice

    PubMed Central

    Xu, Li; Zhang, Guang; Cui, Haoyue

    2016-01-01

    The logistic coupled map lattices (LCML) have been widely investigated as well as their pattern dynamics. The patterns formation may depend on not only fluctuations of system parameters, but variation of the initial conditions. However, the mathematical discussion is quite few for the effect of initial values so far. The present paper is concerned with the pattern formation for a two-dimensional Logistic coupled map lattice, where any initial value can be linear expressed by corresponding eigenvectors, and patterns formation can be determined by selecting the corresponding eigenvectors. A set of simulations are conducted whose results demonstrate the fact. The method utilized in the present paper could be applied to other discrete systems as well. PMID:27382964

  7. 3-D or median map? Earthquake scenario ground-motion maps from physics-based models versus maps from ground-motion prediction equations

    NASA Astrophysics Data System (ADS)

    Porter, K.

    2015-12-01

    There are two common ways to create a ground-motion map for a hypothetical earthquake: using ground motion prediction equations (by far the more common of the two) and using 3-D physics-based modeling. The former is very familiar to engineers, the latter much less so, and the difference can present a problem because engineers tend to trust the familiar and distrust novelty. Maps for essentially the same hypothetical earthquake using the two different methods can look very different, while appearing to present the same information. Using one or the other can lead an engineer or disaster planner to very different estimates of damage and risk. The reasons have to do with depiction of variability, spatial correlation of shaking, the skewed distribution of real-world shaking, and the upward-curving relationship between shaking and damage. The scientists who develop the two kinds of map tend to specialize in one or the other and seem to defend their turf, which can aggravate the problem of clearly communicating with engineers.The USGS Science Application for Risk Reduction's (SAFRR) HayWired scenario has addressed the challenge of explaining to engineers the differences between the two maps, and why, in a disaster planning scenario, one might want to use the less-familiar 3-D map.

  8. NUMERICALLY PREDICTED INDIRECT SIGNATURES OF TERRESTRIAL PLANET FORMATION

    SciTech Connect

    Leinhardt, Zoë M.; Dobinson, Jack; Carter, Philip J.; Lines, Stefan

    2015-06-10

    The intermediate phases of planet formation are not directly observable due to lack of emission from planetesimals. Planet formation is, however, a dynamically active process resulting in collisions between the evolving planetesimals and the production of dust. Thus, indirect observation of planet formation may indeed be possible in the near future. In this paper we present synthetic observations based on numerical N-body simulations of the intermediate phase of planet formation including a state-of-the-art collision model, EDACM, which allows multiple collision outcomes, such as accretion, erosion, and bouncing events. We show that the formation of planetary embryos may be indirectly observable by a fully functioning ALMA telescope if the surface area involved in planetesimal evolution is sufficiently large and/or the amount of dust produced in the collisions is sufficiently high in mass.

  9. Dynamic shifts in the owl's auditory space map predict moving sound location.

    PubMed

    Witten, Ilana B; Bergan, Joseph F; Knudsen, Eric I

    2006-11-01

    The optic tectum of the barn owl contains a map of auditory space. We found that, in response to moving sounds, the locations of receptive fields that make up the map shifted toward the approaching sound. The magnitude of the receptive field shifts increased systematically with increasing stimulus velocity and, therefore, was appropriate to compensate for sensory and motor delays inherent to auditory orienting behavior. Thus, the auditory space map is not static, but shifts adaptively and dynamically in response to stimulus motion. We provide a computational model to account for these results. Because the model derives predictive responses from processes that are known to occur commonly in neural networks, we hypothesize that analogous predictive responses will be found to exist widely in the central nervous system. This hypothesis is consistent with perceptions of stimulus motion in humans for many sensory parameters. PMID:17013379

  10. Preliminary investigation of Large Format Camera photography utility in soil mapping and related agricultural applications

    NASA Technical Reports Server (NTRS)

    Pelletier, R. E.; Hudnall, W. H.

    1987-01-01

    The use of Space Shuttle Large Format Camera (LFC) color, IR/color, and B&W images in large-scale soil mapping is discussed and illustrated with sample photographs from STS 41-6 (October 1984). Consideration is given to the characteristics of the film types used; the photographic scales available; geometric and stereoscopic factors; and image interpretation and classification for soil-type mapping (detecting both sharp and gradual boundaries), soil parent material topographic and hydrologic assessment, natural-resources inventory, crop-type identification, and stress analysis. It is suggested that LFC photography can play an important role, filling the gap between aerial and satellite remote sensing.

  11. Bone morphogenetic proteins, eye patterning, and retinocollicular map formation in the mouse

    PubMed Central

    Plas, Daniel T.; Dhande, Onkar; Lopez, Joshua E.; Murali, Deepa; Thaller, Christina; Henkemeyer, Mark; Furuta, Yasuhide; Overbeek, Paul; Crair, Michael C.

    2009-01-01

    Patterning events during early eye formation determine retinal cell fate and can dictate the behavior of retinal ganglion cell (RGC) axons as they navigate toward central brain targets. The temporally and spatially regulated expression of bone morphogenetic proteins (BMPs) and their receptors in the retina are thought to play a key role in this process, initiating gene expression cascades that distinguish different regions of the retina, particularly along the dorsoventral axis. Here, we examine the role of BMP and a potential downstream effector, EphB, in retinotopic map formation in the lateral geniculate nucleus (LGN) and superior colliculus (SC). RGC axon behaviors during retinotopic map formation in wild type mice are compared with those in several strains of mice with engineered defects of BMP and EphB signaling. Normal RGC axon sorting produces axon order in the optic tract that reflects the dorsoventral position of the parent RGCs in the eye. A dramatic consequence of disrupting BMP signaling is a missorting of RGC axons as they exit the optic chiasm. This sorting is not dependent on EphB. When BMP signaling in the developing eye is genetically modified, RGC order in the optic tract and targeting in the LGN and SC are correspondingly disrupted. These experiments show that BMP signaling regulates dorsoventral RGC cell fate, RGC axon behavior in the ascending optic tract and retinotopic map formation in the LGN and SC through mechanisms that are in part distinct from EphB signaling in the LGN and SC. PMID:18614674

  12. Monitoring the formation of kernel-based topographic maps in a hybrid SOM-kMER model.

    PubMed

    Teh, Chee Siong; Lim, Chee Peng

    2006-09-01

    A new lattice disentangling monitoring algorithm for a hybrid self-organizing map-kernel-based maximum entropy learning rule (SOM-kMER) model is proposed. It aims to overcome topological defects owing to a rapid decrease of the neighborhood range over the finite running time in topographic map formation. The empirical results demonstrate that the proposed approach is able to accelerate the formation of a topographic map and, at the same time, to simplify the monitoring procedure.

  13. Mapping

    ERIC Educational Resources Information Center

    Kinney, Douglas M.; McIntosh, Willard L.

    1978-01-01

    Geologic mapping in the United States increased by about one-quarter in the past year. Examinations of mapping trends were in the following categories: (1) Mapping at scales of 1:100, 000; (2) Metric-scale base maps; (3) International mapping, and (4) Planetary mapping. (MA)

  14. An Approach for Predicting Essential Genes Using Multiple Homology Mapping and Machine Learning Algorithms

    PubMed Central

    Hua, Hong-Li; Zhang, Fa-Zhan; Labena, Abraham Alemayehu; Dong, Chuan; Jin, Yan-Ting

    2016-01-01

    Investigation of essential genes is significant to comprehend the minimal gene sets of cell and discover potential drug targets. In this study, a novel approach based on multiple homology mapping and machine learning method was introduced to predict essential genes. We focused on 25 bacteria which have characterized essential genes. The predictions yielded the highest area under receiver operating characteristic (ROC) curve (AUC) of 0.9716 through tenfold cross-validation test. Proper features were utilized to construct models to make predictions in distantly related bacteria. The accuracy of predictions was evaluated via the consistency of predictions and known essential genes of target species. The highest AUC of 0.9552 and average AUC of 0.8314 were achieved when making predictions across organisms. An independent dataset from Synechococcus elongatus, which was released recently, was obtained for further assessment of the performance of our model. The AUC score of predictions is 0.7855, which is higher than other methods. This research presents that features obtained by homology mapping uniquely can achieve quite great or even better results than those integrated features. Meanwhile, the work indicates that machine learning-based method can assign more efficient weight coefficients than using empirical formula based on biological knowledge. PMID:27660763

  15. Link prediction based on hyperbolic mapping with community structure for complex networks

    NASA Astrophysics Data System (ADS)

    Wang, Zuxi; Wu, Yao; Li, Qingguang; Jin, Fengdong; Xiong, Wei

    2016-05-01

    Link prediction is becoming a concerned topic in the complex network field in recent years. However, the existing link prediction methods are unsatisfactory for processing topological information and have high time complexity. This paper presents a novel method of Link Prediction with Community Structure (LPCS) based on hyperbolic mapping. Different from the existing link prediction methods, to utilize global structure information of the network, LPCS deals with the network from an overall perspective. LPCS takes full advantage of the community structure and its hierarchical organization to map networks into hyperbolic space, and obtains the hyperbolic coordinates which depict the global structure information of the network, then uses hyperbolic distance to describe the similarity between the nodes, finally predicts missing links according to the degree of the similarity between unconnected node pairs. The combination of the hyperbolic geometry framework and the community structure makes LPCS perform well in predicting missing links, and the time complexity of LPCS is linear, which makes LPCS can be applied to handle large scale networks in acceptable time. LPCS outperforms many state-of-the-art link prediction methods in the networks obeying power-law degree distribution.

  16. An Approach for Predicting Essential Genes Using Multiple Homology Mapping and Machine Learning Algorithms

    PubMed Central

    Hua, Hong-Li; Zhang, Fa-Zhan; Labena, Abraham Alemayehu; Dong, Chuan; Jin, Yan-Ting

    2016-01-01

    Investigation of essential genes is significant to comprehend the minimal gene sets of cell and discover potential drug targets. In this study, a novel approach based on multiple homology mapping and machine learning method was introduced to predict essential genes. We focused on 25 bacteria which have characterized essential genes. The predictions yielded the highest area under receiver operating characteristic (ROC) curve (AUC) of 0.9716 through tenfold cross-validation test. Proper features were utilized to construct models to make predictions in distantly related bacteria. The accuracy of predictions was evaluated via the consistency of predictions and known essential genes of target species. The highest AUC of 0.9552 and average AUC of 0.8314 were achieved when making predictions across organisms. An independent dataset from Synechococcus elongatus, which was released recently, was obtained for further assessment of the performance of our model. The AUC score of predictions is 0.7855, which is higher than other methods. This research presents that features obtained by homology mapping uniquely can achieve quite great or even better results than those integrated features. Meanwhile, the work indicates that machine learning-based method can assign more efficient weight coefficients than using empirical formula based on biological knowledge.

  17. Landscape prediction and mapping of game fish biomass, an ecosystem service of Michigan rivers

    USGS Publications Warehouse

    Esselman, Peter C.; Stevenson, R Jan; Lupi, Frank; Riseng, Catherine M.; Wiley, Michael J.

    2015-01-01

    The increased integration of ecosystem service concepts into natural resource management places renewed emphasis on prediction and mapping of fish biomass as a major provisioning service of rivers. The goals of this study were to predict and map patterns of fish biomass as a proxy for the availability of catchable fish for anglers in rivers and to identify the strongest landscape constraints on fish productivity. We examined hypotheses about fish responses to total phosphorus (TP), as TP is a growth-limiting nutrient known to cause increases (subsidy response) and/or decreases (stress response) in fish biomass depending on its concentration and the species being considered. Boosted regression trees were used to define nonlinear functions that predicted the standing crops of Brook Trout Salvelinus fontinalis, Brown Trout Salmo trutta, Smallmouth Bass Micropterus dolomieu, panfishes (seven centrarchid species), and Walleye Sander vitreus by using landscape and modeled local-scale predictors. Fitted models were highly significant and explained 22–56% of the variation in validation data sets. Nonlinear and threshold responses were apparent for numerous predictors, including TP concentration, which had significant effects on all except the Walleye fishery. Brook Trout and Smallmouth Bass exhibited both subsidy and stress responses, panfish biomass exhibited a subsidy response only, and Brown Trout exhibited a stress response. Maps of reach-specific standing crop predictions showed patterns of predicted fish biomass that corresponded to spatial patterns in catchment area, water temperature, land cover, and nutrient availability. Maps illustrated predictions of higher trout biomass in coldwater streams draining glacial till in northern Michigan, higher Smallmouth Bass and panfish biomasses in warmwater systems of southern Michigan, and high Walleye biomass in large main-stem rivers throughout the state. Our results allow fisheries managers to examine the biomass

  18. Geologic Mapping Applications Using THEMIS Data for the Medusae Fossae Formation, Mars

    NASA Technical Reports Server (NTRS)

    Zimbelman, J. R.; Bender, K. C.; Harris, J. C.

    2003-01-01

    The Medusae Fossae Formation (MFF) is a regionally extensive deposit located along the equator of Mars between roughly 130 and 240 E longitude, the origin of which has stimulated a host of published hypotheses. A volcanic or aeolian origin appear most consistent with Viking and MGS data, but other hypotheses remain viable and new data, as from the Mars Odyssey spacecraft, is likely to stimulate additional hypotheses of origin. NASA is supporting geologic mapping of portions of the MFF deposits, but it is now quite clear that this on-going mapping will need considerable revision as data from the Thermal Emission Imaging System (THEMIS) on Mars Odyssey become available. The daytime IR THEMIS images hold particularly strong potential for providing a new base on which geologic mapping can be carried out, as illustrated by the examples discussed.

  19. Predicting secondary organic aerosol formation rates in southeast Texas

    NASA Astrophysics Data System (ADS)

    Russell, Matthew; Allen, David T.

    2005-04-01

    Rates of secondary organic aerosol (SOA) formation, due to the reactions of aromatics and monoterpenes, were estimated for southeast Texas by incorporating a modified version of the Statewide Air Pollution Research Center's chemical mechanism (SAPRC99) into the Comprehensive Air Quality Model with extensions (CAMx version 3.10). The model included explicit representation of the reactions of five SOA precursors (α-pinene, β-pinene, sabinene, d-limonene, and Δ3-carene). Reactions of each SOA precursor with O3, OH radical, and NO3 radical were included. The model also included separate reactions for low- and high-SOA-yield aromatic groups with the OH radical. SOA yields in the mechanisms were estimated using compound-specific yield information (ΔSOA/ΔHC) derived from smog chamber experiments conducted by J. R. Odum and colleagues and R. J. Griffin and colleagues. The form of the SOA yield model was based on the work of J. R. Odum and colleagues and is a function of existing organic aerosol concentrations. Existing organic aerosol concentrations were estimated on the basis of ambient measurements of total organic carbon in southeast Texas. The reactions of monoterpenes (predominantly α-pinene and β-pinene) with ozone led to the most regional SOA formation, followed by monoterpenes with the nitrate radical. Aromatic-OH reactions led to less regional SOA formation compared to monoterpenes; however, this formation occurs close to the urban and industrial areas of Houston. In contrast, SOA formation due to the reactions of monoterpenes occurred in the forested areas north of the urban area. The results of this study are in qualitative agreement with estimates of SOA formation based on ambient data from the same time period.

  20. The effectiveness of digital soil mapping to predict soil properties over low-relief areas.

    PubMed

    Mosleh, Zohreh; Salehi, Mohammad Hassan; Jafari, Azam; Borujeni, Isa Esfandiarpoor; Mehnatkesh, Abdolmohammad

    2016-03-01

    This study investigates the ability of different digital soil mapping (DSM) approaches to predict some of physical and chemical topsoil properties in the Shahrekord plain of Chaharmahal-Va-Bakhtiari province, Iran. According to a semi-detailed soil survey, 120 soil samples were collected from 0 to 30 cm depth with approximate distance of 750 m. Particle size distribution, coarse fragments (CFs), electrical conductivity (EC), pH, organic carbon (OC), and calcium carbonate equivalent (CCE) were determined. Four machine learning techniques, namely, artificial neural networks (ANNs), boosted regression tree (BRT), generalized linear model (GLM), and multiple linear regression (MLR), were used to identify the relationship between soil properties and auxiliary information (terrain attributes, remote sensing indices, geology map, existing soil map, and geomorphology map). Root-mean-square error (RMSE) and mean error (ME) were considered to determine the performance of the models. Among the studied models, GLM showed the highest performance to predict pH, EC, clay, silt, sand, and CCE, whereas the best model is not necessarily able to make accurate estimation. According to RMSE%, DSM has a good efficiency to predict soil properties with low and moderate variabilities. Terrain attributes were the main predictors among different studied auxiliary information. The accuracy of the estimations with more observations is recommended to give a better understanding about the performance of DSM approach over low-relief areas.

  1. The effectiveness of digital soil mapping to predict soil properties over low-relief areas.

    PubMed

    Mosleh, Zohreh; Salehi, Mohammad Hassan; Jafari, Azam; Borujeni, Isa Esfandiarpoor; Mehnatkesh, Abdolmohammad

    2016-03-01

    This study investigates the ability of different digital soil mapping (DSM) approaches to predict some of physical and chemical topsoil properties in the Shahrekord plain of Chaharmahal-Va-Bakhtiari province, Iran. According to a semi-detailed soil survey, 120 soil samples were collected from 0 to 30 cm depth with approximate distance of 750 m. Particle size distribution, coarse fragments (CFs), electrical conductivity (EC), pH, organic carbon (OC), and calcium carbonate equivalent (CCE) were determined. Four machine learning techniques, namely, artificial neural networks (ANNs), boosted regression tree (BRT), generalized linear model (GLM), and multiple linear regression (MLR), were used to identify the relationship between soil properties and auxiliary information (terrain attributes, remote sensing indices, geology map, existing soil map, and geomorphology map). Root-mean-square error (RMSE) and mean error (ME) were considered to determine the performance of the models. Among the studied models, GLM showed the highest performance to predict pH, EC, clay, silt, sand, and CCE, whereas the best model is not necessarily able to make accurate estimation. According to RMSE%, DSM has a good efficiency to predict soil properties with low and moderate variabilities. Terrain attributes were the main predictors among different studied auxiliary information. The accuracy of the estimations with more observations is recommended to give a better understanding about the performance of DSM approach over low-relief areas. PMID:26920129

  2. A Topological Paradigm for Hippocampal Spatial Map Formation Using Persistent Homology

    PubMed Central

    Dabaghian, Y.; Mémoli, F.; Frank, L.; Carlsson, G.

    2012-01-01

    An animal's ability to navigate through space rests on its ability to create a mental map of its environment. The hippocampus is the brain region centrally responsible for such maps, and it has been assumed to encode geometric information (distances, angles). Given, however, that hippocampal output consists of patterns of spiking across many neurons, and downstream regions must be able to translate those patterns into accurate information about an animal's spatial environment, we hypothesized that 1) the temporal pattern of neuronal firing, particularly co-firing, is key to decoding spatial information, and 2) since co-firing implies spatial overlap of place fields, a map encoded by co-firing will be based on connectivity and adjacency, i.e., it will be a topological map. Here we test this topological hypothesis with a simple model of hippocampal activity, varying three parameters (firing rate, place field size, and number of neurons) in computer simulations of rat trajectories in three topologically and geometrically distinct test environments. Using a computational algorithm based on recently developed tools from Persistent Homology theory in the field of algebraic topology, we find that the patterns of neuronal co-firing can, in fact, convey topological information about the environment in a biologically realistic length of time. Furthermore, our simulations reveal a “learning region” that highlights the interplay between the parameters in combining to produce hippocampal states that are more or less adept at map formation. For example, within the learning region a lower number of neurons firing can be compensated by adjustments in firing rate or place field size, but beyond a certain point map formation begins to fail. We propose that this learning region provides a coherent theoretical lens through which to view conditions that impair spatial learning by altering place cell firing rates or spatial specificity. PMID:22912564

  3. A toolbox for predicting g-quadruplex formation and stability.

    PubMed

    Wong, Han Min; Stegle, Oliver; Rodgers, Simon; Huppert, Julian Leon

    2010-01-01

    G-quadruplexes are four stranded nucleic acid structures formed around a core of guanines, arranged in squares with mutual hydrogen bonding. Many of these structures are highly thermally stable, especially in the presence of monovalent cations, such as those found under physiological conditions. Understanding of their physiological roles is expanding rapidly, and they have been implicated in regulating gene transcription and translation among other functions. We have built a community-focused website to act as a repository for the information that is now being developed. At its core, this site has a detailed database (QuadDB) of predicted G-quadruplexes in the human and other genomes, together with the predictive algorithm used to identify them. We also provide a QuadPredict server, which predicts thermal stability and acts as a repository for experimental data from all researchers. There are also a number of other data sources with computational predictions. We anticipate that the wide availability of this information will be of use both to researchers already active in this exciting field and to those who wish to investigate a particular gene hypothesis.

  4. Axon-axon interactions in neuronal circuit assembly: lessons from olfactory map formation.

    PubMed

    Imai, Takeshi; Sakano, Hitoshi

    2011-11-01

    During the development of the nervous system, neurons often connect axons and dendrites over long distances, which are navigated by chemical cues. During the past few decades, studies on axon guidance have focused on chemical cues provided by the axonal target or intermediate target. However, recent studies have shed light on the roles and mechanisms underlying axon-axon interactions during neuronal circuit assembly. The roles of axon-axon interactions are best exemplified in recent studies on olfactory map formation in vertebrates. Pioneer-follower interaction is essential for the axonal pathfinding process. Pre-target axon sorting establishes the anterior-posterior map order. The temporal order of axonal projection is converted to dorsal-ventral topography with the aid of secreted molecules provided by early-arriving axons. An activity-dependent process to form a discrete map also depends on axon sorting. Thus, an emerging principle of olfactory map formation is the 'self-organisation' of axons rather than the 'lock and key' matching between axons and targets. In this review, we discuss how axon-axon interactions contribute to neuronal circuit assembly. PMID:22103421

  5. The Formation Age of Comets: Predicted Physical and Chemical Trends

    NASA Technical Reports Server (NTRS)

    Nuth, Joesph A., III; Hill, H. G. M.

    2000-01-01

    The chemical composition of a comet has always been considered to be a function of where it formed in the nebula. We suggest that the most important factor in determining a comet's chemistry might actually be when it formed. We present specific predictions of correlations between the dust and volatile components to test our hypothesis.

  6. Mapping galaxy encounters in numerical simulations: the spatial extent of induced star formation

    NASA Astrophysics Data System (ADS)

    Moreno, Jorge; Torrey, Paul; Ellison, Sara L.; Patton, David R.; Bluck, Asa F. L.; Bansal, Gunjan; Hernquist, Lars

    2015-04-01

    We employ a suite of 75 simulations of galaxies in idealized major mergers (stellar mass ratio ˜2.5:1), with a wide range of orbital parameters, to investigate the spatial extent of interaction-induced star formation. Although the total star formation in galaxy encounters is generally elevated relative to isolated galaxies, we find that this elevation is a combination of intense enhancements within the central kpc and moderately suppressed activity at larger galactocentric radii. The radial dependence of the star formation enhancement is stronger in the less massive galaxy than in the primary, and is also more pronounced in mergers of more closely aligned disc spin orientations. Conversely, these trends are almost entirely independent of the encounter's impact parameter and orbital eccentricity. Our predictions of the radial dependence of triggered star formation, and specifically the suppression of star formation beyond kpc-scales, will be testable with the next generation of integral-field spectroscopic surveys.

  7. Predicting weed migration from soil and climate maps. [Centaurea maculosa Lam

    SciTech Connect

    Chicoine, T.K.; Fay, P.K.; Nielsen, G.A.

    1985-01-01

    Soil characteristics, elevation, annual precipitation, potential evapotranspiration, length of frost-free season, and mean maximum July temperature were estimated for 116 established infestations of spotted knapweed (Centaurea maculosa Lam. number/sup 3/ CENMA) in Montana using basic land resource maps. Areas potentially vulnerable to invasion by the plant were delineated on the basis of representative edaphic and climatic characteristics. No single environmental variable was an effective predictor of sites vulnerable to invasion by spotted knapweed. Only a combination of variables was effective, indicating that the factors that regulate adaptability of this plant are complex. This technique provides a first approximation map of the regions most similar environmentally to infested sites and; therefore, most vulnerable to further invasion. This weed migration prediction technique shows promise for predicting suitable habitats of other invader species. 6 references, 4 figures, 1 table.

  8. Theoretical predictions and experimental observations of genomic mapping by anchoring random clones

    SciTech Connect

    Grigoriev, A.V. )

    1993-02-01

    Genome mapping by anchoring random clones has recently been the subject of intensive theoretical study. In this paper, differences between published predictions of properties of anchored groups of clones ( contigs') are analyzed and simplifications of the mathematical formulae describing these properties are presented. The theoretical predictions are compared with the experimental results from the physical mapping of the genome of Schizosaccharomyces pombe. Information about the number of genome sections with no anchored clone on them ( oceans') and the number of undetected overlaps between the contigs at a given stage of the experiment is required for the decision to change from the random strategy to that of a directed closure of gaps. We demonstrate that the expected number of oceans can be approximated by the number of groups of clones anchored by a single probe ( singletons'), as can the expected number of undetected overlaps between contigs by the number of contigs containing more than one anchor. 14 refs., 4 figs.

  9. Predictive modeling of synergistic effects in nanoscale ion track formation

    DOE PAGES

    Zarkadoula, Eva; Pakarinen, Olli H.; Xue, Haizhou; Zhang, Yanwen; Weber, William J.

    2015-08-05

    Molecular dynamics techniques and the inelastic thermal spike model are used to study the coupled effects of inelastic energy loss due to 21 MeV Ni ion irradiation and pre-existing defects in SrTiO3. We determine the dependence on pre-existing defect concentration of nanoscale track formation occurring from the synergy between the inelastic energy loss and the pre-existing atomic defects. We show that the nanoscale ion tracks’ size can be controlled by the concentration of pre-existing disorder. This work identifies a major gap in fundamental understanding concerning the role played by defects in electronic energy dissipation and electron–lattice coupling.

  10. A universal and efficient method to compute maps from image-based prediction models.

    PubMed

    Sabuncu, Mert R

    2014-01-01

    Discriminative supervised learning algorithms, such as Support Vector Machines, are becoming increasingly popular in biomedical image computing. One of their main uses is to construct image-based prediction models, e.g., for computer aided diagnosis or "mind reading." A major challenge in these applications is the biological interpretation of the machine learning models, which can be arbitrarily complex functions of the input features (e.g., as induced by kernel-based methods). Recent work has proposed several strategies for deriving maps that highlight regions relevant for accurate prediction. Yet most of these methods o n strong assumptions about t he prediction model (e.g., linearity, sparsity) and/or data (e.g., Gaussianity), or fail to exploit the covariance structure in the data. In this work, we propose a computationally efficient and universal framework for quantifying associations captured by black box machine learning models. Furthermore, our theoretical perspective reveals that examining associations with predictions, in the absence of ground truth labels, can be very informative. We apply the proposed method to machine learning models trained to predict cognitive impairment from structural neuroimaging data. We demonstrate that our approach yields biologically meaningful maps of association. PMID:25320819

  11. Gogo Receptor Contributes to Retinotopic Map Formation and Prevents R1-6 Photoreceptor Axon Bundling

    PubMed Central

    Hein, Irina; Suzuki, Takashi; Grunwald Kadow, Ilona C.

    2013-01-01

    Background Topographic maps form the basis of neural processing in sensory systems of both vertebrate and invertebrate species. In the Drosophila visual system, neighboring R1–R6 photoreceptor axons innervate adjacent positions in the first optic ganglion, the lamina, and thereby represent visual space as a continuous map in the brain. The mechanisms responsible for the establishment of retinotopic maps remain incompletely understood. Results Here, we show that the receptor Golden goal (Gogo) is required for R axon lamina targeting and cartridge elongation in a partially redundant fashion with local guidance cues provided by neighboring axons. Loss of function of Gogo in large clones of R axons results in aberrant R1–R6 fascicle spacing. Gogo affects target cartridge selection only indirectly as a consequence of the disordered lamina map. Interestingly, small clones of gogo deficient R axons perfectly integrate into a proper retinotopic map suggesting that surrounding R axons of the same or neighboring fascicles provide complementary spatial guidance. Using single photoreceptor type rescue, we show that Gogo expression exclusively in R8 cells is sufficient to mediate targeting of all photoreceptor types in the lamina. Upon lamina targeting and cartridge selection, R axons elongate within their individual cartridges. Interestingly, here Gogo prevents bundling of extending R1-6 axons. Conclusion Taken together, we propose that Gogo contributes to retinotopic map formation in the Drosophila lamina by controlling the distribution of R1–R6 axon fascicles. In a later developmental step, the regular position of R1–R6 axons along the lamina plexus is crucial for target cartridge selection. During cartridge elongation, Gogo allows R1–R6 axons to extend centrally in the lamina cartridge. PMID:23826162

  12. Formation and Evolution of Lakshmi Planum (V-7), Venus: Assessment of Models using Observations from Geological Mapping

    NASA Technical Reports Server (NTRS)

    Ivanov, M. A.; Head, James W.

    2008-01-01

    Lakshmi Planum is a high-standing plateau (3.5-4.5 km above MPR) surrounded by the highest mountain ranges on Venus. Lakshmi represents a unique type of elevated region different from dome-shaped and rifted rises and tessera-bearing crustal plateaus. The unique characteristics of Lakshmi suggest that it formed by an unusual combination of processes and played an important role in Venus geologic history. Lakshmi was studied with Venera-15/16 and Magellan data, resulting in two classes of models, divergent and convergent, to explain its unusual topographic and morphologic characteristics. Divergent models explain Lakshmi as a site of mantle upwelling due to rising and subsequent collapse of a mantle diapir; such models explain emplacement of a lava plateau inside Lakshmi and, in some circumstances, formation of the mountain ranges. The convergent models consider Lakshmi as a locus of mantle downwelling, convergence, underthrusting, and possible subduction. Key features in these models are the mountain ranges, high topography of Lakshmi interior, and the large volcanic centers in the plateau center. These divergent and convergent models entail principally different mechanisms of formation and suggest different geodynamic regimes on Venus. Almost all models make either explicit or implicit predictions about the type and sequence of major events during formation and evolution of Lakshmi and thus detailed geological mapping can be used to test them. Here we present the results of such geological mapping (the V-7 quadrangle, 50-75degN, 300-360degE; scale 1:5M) that allows testing the proposed models for Lakshmi.

  13. Predictive modeling of synergistic effects in nanoscale ion track formation

    SciTech Connect

    Zarkadoula, Eva; Pakarinen, Olli H.; Xue, Haizhou; Zhang, Yanwen; Weber, William J.

    2015-08-05

    Molecular dynamics techniques and the inelastic thermal spike model are used to study the coupled effects of inelastic energy loss due to 21 MeV Ni ion irradiation and pre-existing defects in SrTiO3. We determine the dependence on pre-existing defect concentration of nanoscale track formation occurring from the synergy between the inelastic energy loss and the pre-existing atomic defects. We show that the nanoscale ion tracks’ size can be controlled by the concentration of pre-existing disorder. This work identifies a major gap in fundamental understanding concerning the role played by defects in electronic energy dissipation and electron–lattice coupling.

  14. Using global maps to predict the risk of dengue in Europe.

    PubMed

    Rogers, David J; Suk, Jonathan E; Semenza, Jan C

    2014-01-01

    This article attempts to quantify the risk to Europe of dengue, following the arrival and spread there of one of dengue's vector species Aedes (Stegomyia) albopictus. A global risk map for dengue is presented, based on a global database of the occurrence of this disease, derived from electronic literature searches. Remotely sensed satellite data (from NASA's MODIS series), interpolated meteorological data, predicted distribution maps of dengue's two main vector species, Aedes aegypti and Aedes albopictus, a digital elevation surface and human population density data were all used as potential predictor variables in a non-linear discriminant analysis modelling framework. One hundred bootstrap models were produced by randomly sub-sampling three different training sets for dengue fever, severe dengue (i.e. dengue haemorrhagic fever, DHF) and all-dengue, and output predictions were averaged to produce a single global risk map for each type of dengue. This paper concentrates on the all-dengue models. Key predictor variables were various thermal data layers, including both day- and night-time Land Surface Temperature, human population density, and a variety of rainfall variables. The relative importance of each may be shown visually using rainbow files and quantitatively using a ranking system. Vegetation Index variables (a common proxy for humidity or saturation deficit) were rarely chosen in the models. The kappa index of agreement indicated an excellent (dengue haemorrhagic fever, Cohen's kappa=0.79 ± 0.028, AUC=0.96 ± 0.007) or good fit of the top ten models in each series to the data (Cohen's kappa=0.73 ± 0.018, AUC=0.94 ± 0.007 for dengue fever and 0.74 ± 0.017, AUC=0.95 ± 0.005 for all dengue). The global risk map predicts widespread dengue risk in SE Asia and India, in Central America and parts of coastal South America, but in relatively few regions of Africa. In many cases these are less extensive predictions than those of other published dengue risk maps

  15. Using global maps to predict the risk of dengue in Europe.

    PubMed

    Rogers, David J; Suk, Jonathan E; Semenza, Jan C

    2014-01-01

    This article attempts to quantify the risk to Europe of dengue, following the arrival and spread there of one of dengue's vector species Aedes (Stegomyia) albopictus. A global risk map for dengue is presented, based on a global database of the occurrence of this disease, derived from electronic literature searches. Remotely sensed satellite data (from NASA's MODIS series), interpolated meteorological data, predicted distribution maps of dengue's two main vector species, Aedes aegypti and Aedes albopictus, a digital elevation surface and human population density data were all used as potential predictor variables in a non-linear discriminant analysis modelling framework. One hundred bootstrap models were produced by randomly sub-sampling three different training sets for dengue fever, severe dengue (i.e. dengue haemorrhagic fever, DHF) and all-dengue, and output predictions were averaged to produce a single global risk map for each type of dengue. This paper concentrates on the all-dengue models. Key predictor variables were various thermal data layers, including both day- and night-time Land Surface Temperature, human population density, and a variety of rainfall variables. The relative importance of each may be shown visually using rainbow files and quantitatively using a ranking system. Vegetation Index variables (a common proxy for humidity or saturation deficit) were rarely chosen in the models. The kappa index of agreement indicated an excellent (dengue haemorrhagic fever, Cohen's kappa=0.79 ± 0.028, AUC=0.96 ± 0.007) or good fit of the top ten models in each series to the data (Cohen's kappa=0.73 ± 0.018, AUC=0.94 ± 0.007 for dengue fever and 0.74 ± 0.017, AUC=0.95 ± 0.005 for all dengue). The global risk map predicts widespread dengue risk in SE Asia and India, in Central America and parts of coastal South America, but in relatively few regions of Africa. In many cases these are less extensive predictions than those of other published dengue risk maps

  16. The high-redshift star formation history from carbon-monoxide intensity maps

    NASA Astrophysics Data System (ADS)

    Breysse, Patrick C.; Kovetz, Ely D.; Kamionkowski, Marc

    2016-03-01

    We demonstrate how cosmic star formation history can be measured with one-point statistics of carbon-monoxide intensity maps. Using a P(D) analysis, the luminosity function of CO-emitting sources can be inferred from the measured one-point intensity PDF. The star formation rate density (SFRD) can then be obtained, at several redshifts, from the CO luminosity density. We study the effects of instrumental noise, line foregrounds, and target redshift, and obtain constraints on the CO luminosity density of the order of 10 per cent. We show that the SFRD uncertainty is dominated by that of the model connecting CO luminosity and star formation. For pessimistic estimates of this model uncertainty, we obtain an error of the order of 50 per cent on SFRD for surveys targeting redshifts between two and seven with reasonable noise and foregrounds included. However, comparisons between intensity maps and galaxies could substantially reduce this model uncertainty. In this case, our constraints on SFRD at these redshifts improve to roughly 5 - 10 per cent, which is highly competitive with current measurements.

  17. Map-making for Large-Format Detector Arrays on CCAT

    NASA Astrophysics Data System (ADS)

    Marsden, G.; Jenness, T.; Scott, D.

    2015-09-01

    CCAT is a large submillimetre telescope to be built near the ALMA site in northern Chile. A large-format KID camera, with up to 48,000 detectors at a single waveband sampled at ˜1 kHz, will have a data rate ˜50 times larger than SCUBA-2, the largest existing submillimetre camera. Creating a map from this volume of data will be a challenge, both in terms of memory and processing time required. We investigate how to extend SMURF, the iterative map-maker used for reducing SCUBA-2 observations, to a distributed-node parallel system, and estimate how the processing time scales with the number of nodes in the system.

  18. Map showing structure contours on the top of the upper Jurassic Morrison Formation, Powder River basin, Wyoming and Montana

    USGS Publications Warehouse

    Crysdale, B.L.

    1991-01-01

    This map is one in a series of U.S. Geological Survey Miscellaneous Field Studies (MF) maps showing computer-generated structure contours, isopachs, and cross sections of selected formations in the Powder River basin, Wyoming and Montana. The map and cross sections were constructed from information stored in a U.S. Geological Survey Evolution of Sedimentary Basins data base. This data base contains picks of geologic formation and (or) unit tops and bases determined from electric resistivity and gamma-ray logs of 8,592 wells penetrating Tertiary and older rocks in the Powder River basin. Well completion cards (scout tickets) were reviewed and compared with copies of all logs, and formation or unit contacts determined by N. M. Denson, D.L. Macke, R. R. Schumann and others. This isopach map is based on information from 2,429 of these wells that penetrate the Minnelusa Formation and equivalents.

  19. Spatial Mapping of NEO 2008 EV5 Using Small Satellite Formation Flying and Steresoscopic Technology

    NASA Astrophysics Data System (ADS)

    Gonzalez, Juan; Singh Derewa, Chrishma

    2016-10-01

    NASA is currently developing the first-ever robotic Asteroid Redirect Robotic Mission (ARRM) to the near-Earth asteroid 2008 EV5 with the objective to capture a multi-ton boulder from the asteroids surface and use its mass to redirect its parent into a CIS lunar orbit where astronauts will study its physical and chemical composition.A critical step towards achieving this mission is to effectively map the target asteroid, identify the candidate boulder for retrieval and characterize its critical parameters. Currently, ARRM utilizes a laser altimeter to characterize the height of the boulders and mapping for final autonomous control of the capture. The proposed Lava-Kusha mission provides the increased of stereoscopic imaging and mapping, not only the Earthward side of the asteroid which has been observed for possible landing sites, but mapping the whole asteroid. LKM will enhance the fidelity of the data collected by the laser altimeter and gather improved topographic data for future Orion missions to 2008 EV5 once in cis lunar space.LKM consists of two low cost small satellites (6U) as a part of the ARRM. They will launch with ARRM as an integrated part of the system. Once at the target, this formation of pathfinder satellites will image the mission critical boulder to ensure the system design can support its removal. LKM will conduct a series of flybys prior to ARRM's rendezvous. LKMs stereoscopic cameras will provide detailed surveys of the boulder's terrain and environment to ensure ARRM can operate safely, reach the location and interface with the boulder. The LKM attitude control and cold gas propulsion system will enable formation maintenance maneuvers for global mapping of asteroid 2008 EV5 at an altitude of 100 km to a high-spatial resolution imaging altitude of 5 km.LKM will demonstrate formation flying in deep space and the reliability of stereoscopic cameras to precisely identify a specific target and provide physical characterization of an asteroid. An

  20. Predictive Multiple Model Switching Control with the Self-Organizing Map

    NASA Technical Reports Server (NTRS)

    Motter, Mark A.

    2000-01-01

    A predictive, multiple model control strategy is developed by extension of self-organizing map (SOM) local dynamic modeling of nonlinear autonomous systems to a control framework. Multiple SOMs collectively model the global response of a nonautonomous system to a finite set of representative prototype controls. Each SOM provides a codebook representation of the dynamics corresponding to a prototype control. Different dynamic regimes are organized into topological neighborhoods where the adjacent entries in the codebook represent the global minimization of a similarity metric. The SOM is additionally employed to identify the local dynamical regime, and consequently implements a switching scheme that selects the best available model for the applied control. SOM based linear models are used to predict the response to a larger family of control sequences which are clustered on the representative prototypes. The control sequence which corresponds to the prediction that best satisfies the requirements on the system output is applied as the external driving signal.

  1. Prediction interval evaluation in modelling of soil texture for regional mapping: methodology and a case study

    NASA Astrophysics Data System (ADS)

    Ciampalini, Rossano; Martin, Manuel; Saby, Nicolas P. A.; Richer de Forges, Anne C.; Nehlig, Pierre; Martelet, Guillaume; Arrouays, Dominique

    2015-04-01

    Model uncertainty mapping represents a practical way to describe efficiency and limits of models prediction and can be calculated using different techniques. The object of this study is to determine and apply a procedure for the prediction interval (PI) evaluation for extended maps of soil granulometric fractions (i.e. clay, silt, sand) in the region "Centre" of France. Among the various methodologies for PI determination, a recent approach is the use of a non-parametric procedure evaluating the prediction interval. The PI is defined as a conventional bound of the predicted values (i.e. 95th percentile) and can be calculated as follows. Assuming a relationship between the inputs of the model and the resulting prediction error (Shrestha et al., 2006, Malone et al., 2011), the input variables-space is classified into different clusters having similar errors with a fuzzy c-means clustering technique. Then, a prediction interval (PI) is calculated for each cluster on the basis of the associated empirical distributions of the errors and considering the degree of membership belonging to each cluster. A relationship between the input variables and the computed prediction intervals is founded using a modelling procedure (calibration), then; the relationship is applied to estimate the prediction interval for the out-of-sample data (validation) (e.g. Solomatine et al., 2008, 2009, Malone et al., 2011). This approach requires the assumption of a relationships between the input variables and the errors, and, obviously the relevancy and accuracy of such approach depends on the validity of the assumption. These assumptions have been accepted in all the studies quoted above. In this work we adopted a similar procedure to the third approach. Our hypothesis is, if a correspondence is supposed and identified between confidence interval and predictors (i.e., 2.5-97.5% values, respectively), a model between predictors and PI may be used to extrapolate it to the whole map. This

  2. SDS-PAGE and two-dimensional maps in a radial gel format.

    PubMed

    Millioni, Renato; Miuzzo, Manuela; Antonioli, Paolo; Sbrignadello, Stefano; Iori, Elisabetta; Dosselli, Ryan; Puricelli, Lucia; Kolbe, Markus; Tessari, Paolo; Righetti, Pier Giorgio

    2010-01-01

    A novel method for performing 2-D map analysis is here reported, consisting in a modification of the second dimension run, which is performed not in a conventional square- or rectangular-size gel, but in a radial surface. This has the advantage of permitting resolution of closely adjacent bands, representing strings of isoforms of similar or identical mass but of closely spaced isoelectric points. When used in a mono-dimensional, SDS-PAGE format, this system allows the simultaneous running of 62 sample tracks. Examples are given of separation of plasma and urinary proteins. PMID:20119955

  3. The Formation Age of Comets: Predicted Physical and Chemical Trends

    NASA Technical Reports Server (NTRS)

    Nuth, Joseph A., III; Hill, Hugh G. M.

    2000-01-01

    Dust grains in Herbig Ae/Be stars are continuously replenished by infalling comets. The IR spectra of these cometary grains appear to evolve temporally from initially amorphous astronomical silicates in young protostars to crystalline olivine in much older sources. Crystalline olivine can only be produced from amorphous silicates on a time scale of months-to-years via thermal annealing at temperatures near 1000 K. Since such sustained high temperatures only occur near the central star, dust annealed at 1000 K in inner nebular regions must be continuously transported beyond the nebular snowline to be incorporated into the next generation of cometesimals. The average formation age of a comet can therefore be measured as a ratio of the annealed crystalline olivine dust component to the total dust content of the comet. Comets formed from nearly pristine interstellar materials early in the protostellar nebula stage will contain very little crystalline dust whereas comets formed towards the end of the accretion period will incorporate a much higher percentage of annealed silicate. It is unlikely that only dust grains circulate from the inner to the outer nebula; the gas associated with such dust should also find its way beyond the snowline. Since this gas and dust will have equilibrated in the higher pressure-temperature regime of the inner nebula, it will contain a much higher proportion of hydrocarbons and ammonia than more pristine interstellar ices. Therefore, in addition to a higher fraction of crystalline dust, later forming comets should also contain higher ratios of hydrocarbons to CO and ammonia to N2 than do those formed early in the history of the nebula.

  4. Urban Mapping and Growth Prediction using Remote Sensing and GIS Techniques, Pune, India

    NASA Astrophysics Data System (ADS)

    Sivakumar, V.

    2014-11-01

    This study aims to map the urban area in and around Pune region between the year 1991 and 2010, and predict its probable future growth using remote sensing and GIS techniques. The Landsat TM and ETM+ satellite images of 1991, 2001 and 2010 were used for analyzing urban land use class. Urban class was extracted / mapped using supervised classification technique with maximum likelihood classifier. The accuracy assessment was carried out for classified maps. The achieved overall accuracy and Kappa statistics were 86.33 % & 0.76 respectively. Transition probability matrix and area change were obtained using different classified images. A plug-in was developed in QGIS software (open source) based on Markov Chain model algorithm for predicting probable urban growth for the future year 2021. Based on available data set, the result shows that urban area is expected to grow much higher in the year 2021 when compared to 2010. This study provides an insight into understanding of urban growth and aids in subsequent infrastructure planning, management and decision-making.

  5. Hippocampal size predicts rapid learning of a cognitive map in humans.

    PubMed

    Schinazi, Victor R; Nardi, Daniele; Newcombe, Nora S; Shipley, Thomas F; Epstein, Russell A

    2013-06-01

    The idea that humans use flexible map-like representations of their environment to guide spatial navigation has a long and controversial history. One reason for this enduring controversy might be that individuals vary considerably in their ability to form and utilize cognitive maps. Here we investigate the behavioral and neuroanatomical signatures of these individual differences. Participants learned an unfamiliar campus environment over a period of three weeks. In their first visit, they learned the position of different buildings along two routes in separate areas of the campus. During the following weeks, they learned these routes for a second and third time, along with two paths that connected both areas of the campus. Behavioral assessments after each learning session indicated that subjects formed a coherent representation of the spatial structure of the entire campus after learning a single connecting path. Volumetric analyses of structural MRI data and voxel-based morphometry (VBM) indicated that the size of the right posterior hippocampus predicted the ability to use this spatial knowledge to make inferences about the relative positions of different buildings on the campus. An inverse relationship between gray matter volume and performance was observed in the caudate. These results suggest that (i) humans can rapidly acquire cognitive maps of large-scale environments and (ii) individual differences in hippocampal anatomy may provide the neuroanatomical substrate for individual differences in the ability to learn and flexibly use these cognitive maps. © 2013 Wiley Periodicals, Inc. PMID:23505031

  6. Evaluation of the information content of RNA structure mapping data for secondary structure prediction.

    PubMed

    Quarrier, Scott; Martin, Joshua S; Davis-Neulander, Lauren; Beauregard, Arthur; Laederach, Alain

    2010-06-01

    Structure mapping experiments (using probes such as dimethyl sulfate [DMS], kethoxal, and T1 and V1 RNases) are used to determine the secondary structures of RNA molecules. The process is iterative, combining the results of several probes with constrained minimum free-energy calculations to produce a model of the structure. We aim to evaluate whether particular probes provide more structural information, and specifically, how noise in the data affects the predictions. Our approach involves generating "decoy" RNA structures (using the sFold Boltzmann sampling procedure) and evaluating whether we are able to identify the correct structure from this ensemble of structures. We show that with perfect information, we are always able to identify the optimal structure for five RNAs of known structure. We then collected orthogonal structure mapping data (DMS and RNase T1 digest) under several solution conditions using our high-throughput capillary automated footprinting analysis (CAFA) technique on two group I introns of known structure. Analysis of these data reveals the error rates in the data under optimal (low salt) and suboptimal solution conditions (high MgCl(2)). We show that despite these errors, our computational approach is less sensitive to experimental noise than traditional constraint-based structure prediction algorithms. Finally, we propose a novel approach for visualizing the interaction of chemical and enzymatic mapping data with RNA structure. We project the data onto the first two dimensions of a multidimensional scaling of the sFold-generated decoy structures. We are able to directly visualize the structural information content of structure mapping data and reconcile multiple data sets.

  7. Predictive Factors and Risk Mapping for Rift Valley Fever Epidemics in Kenya

    PubMed Central

    Munyua, Peninah M.; Murithi, R. Mbabu; Ithondeka, Peter; Hightower, Allen; Thumbi, Samuel M.; Anyangu, Samuel A.; Kiplimo, Jusper; Bett, Bernard; Vrieling, Anton; Breiman, Robert F.; Njenga, M. Kariuki

    2016-01-01

    Background To-date, Rift Valley fever (RVF) outbreaks have occurred in 38 of the 69 administrative districts in Kenya. Using surveillance records collected between 1951 and 2007, we determined the risk of exposure and outcome of an RVF outbreak, examined the ecological and climatic factors associated with the outbreaks, and used these data to develop an RVF risk map for Kenya. Methods Exposure to RVF was evaluated as the proportion of the total outbreak years that each district was involved in prior epizootics, whereas risk of outcome was assessed as severity of observed disease in humans and animals for each district. A probability-impact weighted score (1 to 9) of the combined exposure and outcome risks was used to classify a district as high (score ≥ 5) or medium (score ≥2 - <5) risk, a classification that was subsequently subjected to expert group analysis for final risk level determination at the division levels (total = 391 divisions). Divisions that never reported RVF disease (score < 2) were classified as low risk. Using data from the 2006/07 RVF outbreak, the predictive risk factors for an RVF outbreak were identified. The predictive probabilities from the model were further used to develop an RVF risk map for Kenya. Results The final output was a RVF risk map that classified 101 of 391 divisions (26%) located in 21 districts as high risk, and 100 of 391 divisions (26%) located in 35 districts as medium risk and 190 divisions (48%) as low risk, including all 97 divisions in Nyanza and Western provinces. The risk of RVF was positively associated with Normalized Difference Vegetation Index (NDVI), low altitude below 1000m and high precipitation in areas with solonertz, luvisols and vertisols soil types (p <0.05). Conclusion RVF risk map serves as an important tool for developing and deploying prevention and control measures against the disease. PMID:26808021

  8. Evaluation of the information content of RNA structure mapping data for secondary structure prediction.

    PubMed

    Quarrier, Scott; Martin, Joshua S; Davis-Neulander, Lauren; Beauregard, Arthur; Laederach, Alain

    2010-06-01

    Structure mapping experiments (using probes such as dimethyl sulfate [DMS], kethoxal, and T1 and V1 RNases) are used to determine the secondary structures of RNA molecules. The process is iterative, combining the results of several probes with constrained minimum free-energy calculations to produce a model of the structure. We aim to evaluate whether particular probes provide more structural information, and specifically, how noise in the data affects the predictions. Our approach involves generating "decoy" RNA structures (using the sFold Boltzmann sampling procedure) and evaluating whether we are able to identify the correct structure from this ensemble of structures. We show that with perfect information, we are always able to identify the optimal structure for five RNAs of known structure. We then collected orthogonal structure mapping data (DMS and RNase T1 digest) under several solution conditions using our high-throughput capillary automated footprinting analysis (CAFA) technique on two group I introns of known structure. Analysis of these data reveals the error rates in the data under optimal (low salt) and suboptimal solution conditions (high MgCl(2)). We show that despite these errors, our computational approach is less sensitive to experimental noise than traditional constraint-based structure prediction algorithms. Finally, we propose a novel approach for visualizing the interaction of chemical and enzymatic mapping data with RNA structure. We project the data onto the first two dimensions of a multidimensional scaling of the sFold-generated decoy structures. We are able to directly visualize the structural information content of structure mapping data and reconcile multiple data sets. PMID:20413617

  9. Mapping.

    ERIC Educational Resources Information Center

    Kinney, Douglas M.; McIntosh, Willard L.

    1979-01-01

    The area of geological mapping in the United States in 1978 increased greatly over that reported in 1977; state geological maps were added for California, Idaho, Nevada, and Alaska last year. (Author/BB)

  10. Mapping, Bayesian Geostatistical Analysis and Spatial Prediction of Lymphatic Filariasis Prevalence in Africa

    PubMed Central

    Slater, Hannah; Michael, Edwin

    2013-01-01

    There is increasing interest to control or eradicate the major neglected tropical diseases. Accurate modelling of the geographic distributions of parasitic infections will be crucial to this endeavour. We used 664 community level infection prevalence data collated from the published literature in conjunction with eight environmental variables, altitude and population density, and a multivariate Bayesian generalized linear spatial model that allows explicit accounting for spatial autocorrelation and incorporation of uncertainty in input data and model parameters, to construct the first spatially-explicit map describing LF prevalence distribution in Africa. We also ran the best-fit model against predictions made by the HADCM3 and CCCMA climate models for 2050 to predict the likely distributions of LF under future climate and population changes. We show that LF prevalence is strongly influenced by spatial autocorrelation between locations but is only weakly associated with environmental covariates. Infection prevalence, however, is found to be related to variations in population density. All associations with key environmental/demographic variables appear to be complex and non-linear. LF prevalence is predicted to be highly heterogenous across Africa, with high prevalences (>20%) estimated to occur primarily along coastal West and East Africa, and lowest prevalences predicted for the central part of the continent. Error maps, however, indicate a need for further surveys to overcome problems with data scarcity in the latter and other regions. Analysis of future changes in prevalence indicates that population growth rather than climate change per se will represent the dominant factor in the predicted increase/decrease and spread of LF on the continent. We indicate that these results could play an important role in aiding the development of strategies that are best able to achieve the goals of parasite elimination locally and globally in a manner that may also account

  11. Noninvasive electrocardiographic mapping for prediction of tachycardia mechanism and origin of atrial tachycardia following bilateral pulmonary transplantation.

    PubMed

    Roten, Laurent; Pedersen, Michala; Pascale, Patrizio; Shah, Ashok; Eliautou, Sandra; Scherr, Daniel; Sacher, Frederic; Haïssaguerre, Michel

    2012-05-01

    This is a case of atrial tachycardia 2 years after pulmonary transplantation. After excluding right atrial involvement, tachycardia origin was located in a scar region medial to the anastomosis of the left inferior pulmonary donor vein. Tachycardia mechanism was microreentry. Noninvasive electrocardiographic mapping performed before the ablation procedure matched with results of invasive Carto mapping and predicted both tachycardia mechanism and origin. We discuss arrhythmia mechanism found after pulmonary transplantation and benefit of noninvasive electrocardiographic mapping for procedure planning.

  12. [Optimal formation conditions and analytical methods of the target product by MAP precipitation].

    PubMed

    Hao, Xiao-Di; Lan, Li; Wang, Chong-Chen; van Loosdrecht, M C M

    2009-04-15

    In order to establish optimal conditions of the struvite (MAP: MgNH4PO4 x 6H2O) formation, acid dissolution was applied and developed to perform element analyses on the precipitates obtained from MAP precipitation, and a novel analyzing and calculating method was developed to quantitatively determine the struvite content (purity) in the harvested precipitates according to the NH4+-N content. With this method, the purities of struvite were respectively determined for both ultra pure water and tap water used as solutes. At the same time, the effect of pH and Ca2+ on the formation and crystallization of struvite was evaluated. The newly developed method was effective enough to determine the purities of struvite, which could be a better method than qualitative X-ray diffraction (XRD). Based on the developed method, it was found that the optimal pH ranges for having a high struvite content (> 90%) were respectively at 7.5-9.0 with ultra pure water as solute and at 7.0-7.5 with tap water as solute. In real wastewater, Ca2+ at pH > 8.0 might result in impurities rather than struvite. Therefore, a neutral pH range (< 8.0) is proposed to perform struvite precipitation in wastewater.

  13. Predictive mapping of soil properties at high resolution by component wise gradient boosting

    NASA Astrophysics Data System (ADS)

    Nussbaum, Madlene; Papritz, Andreas; Fraefel, Marielle; Baltensweiler, Andri; Keller, Armin

    2015-04-01

    Accurate spatial information on soils is crucial for sustainable usage of the resource soil. Spatial planning, agriculture, forestry or natural hazards management need high resolution maps of potentials of soils for particular functions (e. g. water storage, nutrient supply). Soil functions are derived from basic soil properties like soil organic carbon or soil texture. For many regions precise maps of basic soil properties are missing. Hence, as a prerequisite for digital soil function mapping, maps of soil properties must be created with the desired resolution. A wide range of statistical approaches (linear and additive models, external drift kriging, Random Forest) were used for this in the past. When numerous environmental covariates (e. g. hyper-spectral remote sensing data) are available the selection of the model with best predictive power is challenging. Besides the issue of covariate selection, one should allow for non-linear effects of covariates on soil properties. To handle these difficulties we used a gradient boosting approach that included besides categorical covariates linear and smooth non-linear terms of continuous covariates as base learners. Residual auto-correlation and non-stationary relationships were modeled by smooth spatial surfaces. Gradient boosting of this flavor selects relevant covariates in a slow learning procedure and inherently models non-linear dependencies on covariates during the fitting process. The restriction to linear and smoothing spline base learners retains the interpretability of the fitted predictive models. The number of boosting iterations is the main tuning parameter and was determined by tenfold cross validation. To explore the feasibility of the gradient boosting approach we mapped pH of forest topsoils in Canton of Zurich, Switzerland, at high (50 m) spatial resolution. Legacy pH measurements were available from 1200 sites in the in the forests of Canton of Zurich. Gradient boosting selected a sparse model with

  14. Geospatial Predictive Modelling for Climate Mapping of Selected Severe Weather Phenomena Over Poland: A Methodological Approach

    NASA Astrophysics Data System (ADS)

    Walawender, Ewelina; Walawender, Jakub P.; Ustrnul, Zbigniew

    2016-02-01

    The main purpose of the study is to introduce methods for mapping the spatial distribution of the occurrence of selected atmospheric phenomena (thunderstorms, fog, glaze and rime) over Poland from 1966 to 2010 (45 years). Limited in situ observations as well the discontinuous and location-dependent nature of these phenomena make traditional interpolation inappropriate. Spatially continuous maps were created with the use of geospatial predictive modelling techniques. For each given phenomenon, an algorithm identifying its favourable meteorological and environmental conditions was created on the basis of observations recorded at 61 weather stations in Poland. Annual frequency maps presenting the probability of a day with a thunderstorm, fog, glaze or rime were created with the use of a modelled, gridded dataset by implementing predefined algorithms. Relevant explanatory variables were derived from NCEP/NCAR reanalysis and downscaled with the use of a Regional Climate Model. The resulting maps of favourable meteorological conditions were found to be valuable and representative on the country scale but at different correlation (r) strength against in situ data (from r = 0.84 for thunderstorms to r = 0.15 for fog). A weak correlation between gridded estimates of fog occurrence and observations data indicated the very local nature of this phenomenon. For this reason, additional environmental predictors of fog occurrence were also examined. Topographic parameters derived from the SRTM elevation model and reclassified CORINE Land Cover data were used as the external, explanatory variables for the multiple linear regression kriging used to obtain the final map. The regression model explained 89 % of annual frequency of fog variability in the study area. Regression residuals were interpolated via simple kriging.

  15. KROSS: mapping the Hα emission across the star formation sequence at z ≈ 1

    NASA Astrophysics Data System (ADS)

    Magdis, Georgios E.; Bureau, Martin; Stott, J. P.; Tiley, A.; Swinbank, A. M.; Bower, R.; Bunker, A. J.; Jarvis, Matt; Johnson, Helen; Sharples, Ray

    2016-03-01

    We present first results from the KMOS (K-band Multi-Object Spectrograph) Redshift One Spectroscopic Survey, an ongoing large kinematical survey of a thousand, z ˜ 1 star-forming galaxies, with VLT KMOS. Out of the targeted galaxies (˜500 so far), we detect and spatially resolve Hα emission in ˜90 and 77 per cent of the sample, respectively. Based on the integrated Hα flux measurements and the spatially resolved maps, we derive a median star formation rate (SFR) of ˜7.0 M⊙ yr-1 and a median physical size of = 5.1 kpc. We combine the inferred SFRs and effective radii measurements to derive the star formation surface densities (ΣSFR) and present a `resolved' version of the star formation main sequence (MS) that appears to hold at subgalactic scales, with similar slope and scatter as the one inferred from galaxy-integrated properties. Our data also yield a trend between ΣSFR and Δ(sSFR) (distance from the MS) suggesting that galaxies with higher sSFR are characterized by denser star formation activity. Similarly, we find evidence for an anticorrelation between the gas phase metallicity (Z) and the Δ(sSFR), suggesting a 0.2 dex variation in the metal content of galaxies within the MS and significantly lower metallicities for galaxies above it. The origin of the observed trends between ΣSFR-Δ(sSFR) and Z-Δ(sSFR) could be driven by an interplay between variations of the gas fraction or the star formation efficiency of the galaxies along and off the MS. To address this, follow-up observations of our sample that will allow gas mass estimates are necessary.

  16. XML-BSPM: an XML format for storing Body Surface Potential Map recordings

    PubMed Central

    2010-01-01

    Background The Body Surface Potential Map (BSPM) is an electrocardiographic method, for recording and displaying the electrical activity of the heart, from a spatial perspective. The BSPM has been deemed more accurate for assessing certain cardiac pathologies when compared to the 12-lead ECG. Nevertheless, the 12-lead ECG remains the most popular ECG acquisition method for non-invasively assessing the electrical activity of the heart. Although data from the 12-lead ECG can be stored and shared using open formats such as SCP-ECG, no open formats currently exist for storing and sharing the BSPM. As a result, an innovative format for storing BSPM datasets has been developed within this study. Methods The XML vocabulary was chosen for implementation, as opposed to binary for the purpose of human readability. There are currently no standards to dictate the number of electrodes and electrode positions for recording a BSPM. In fact, there are at least 11 different BSPM electrode configurations in use today. Therefore, in order to support these BSPM variants, the XML-BSPM format was made versatile. Hence, the format supports the storage of custom torso diagrams using SVG graphics. This diagram can then be used in a 2D coordinate system for retaining electrode positions. Results This XML-BSPM format has been successfully used to store the Kornreich-117 BSPM dataset and the Lux-192 BSPM dataset. The resulting file sizes were in the region of 277 kilobytes for each BSPM recording and can be deemed suitable for example, for use with any telemonitoring application. Moreover, there is potential for file sizes to be further reduced using basic compression algorithms, i.e. the deflate algorithm. Finally, these BSPM files have been parsed and visualised within a convenient time period using a web based BSPM viewer. Conclusions This format, if widely adopted could promote BSPM interoperability, knowledge sharing and data mining. This work could also be used to provide conceptual

  17. Remotely mapping river water quality using multivariate regression with prediction validation.

    SciTech Connect

    Stork, Christopher Lyle; Autry, Bradley C.

    2005-07-01

    Remote spectral sensing offers an attractive means of mapping river water quality over wide spatial regions. While previous research has focused on development of spectral indices and models to predict river water quality based on remote images, little attention has been paid to subsequent validation of these predictions. To address this oversight, we describe a retrospective analysis of remote, multispectral Compact Airborne Spectrographic Imager (CASI) images of the Ohio River and its Licking River and Little Miami River tributaries. In conjunction with the CASI acquisitions, ground truth measurements of chlorophyll-a concentration and turbidity were made for a small set of locations in the Ohio River. Partial least squares regression models relating the remote river images to ground truth measurements of chlorophyll-a concentration and turbidity for the Ohio River were developed. Employing these multivariate models, chlorophyll-a concentrations and turbidity levels were predicted in river pixels lacking ground truth measurements, generating detailed estimated water quality maps. An important but often neglected step in the regression process is to validate prediction results using a spectral residual statistic. For both the chlorophyll-a and turbidity regression models, a spectral residual value was calculated for each river pixel and compared to the associated statistical confidence limit for the model. These spectral residual statistic results revealed that while the chlorophyll-a and turbidity models could validly be applied to a vast majority of Ohio River and Licking River pixels, application of these models to Little Miami River pixels was inappropriate due to an unmodeled source of spectral variation.

  18. Predictive Modeling and Mapping of Fish Distributions in Small Streams of the Canadian Rocky Mountain Foothills

    NASA Astrophysics Data System (ADS)

    McCleary, R. J.; Hassan, M. A.

    2006-12-01

    An automated procedure was developed to model spatial fish distributions within small streams in the Foothills of Alberta. Native fish populations and their habitats are susceptible to impacts arising from both industrial forestry and rapid development of petroleum resources in the region. Knowledge of fish distributions and the effects of industrial activities on their habitats is required to help conserve native fish populations. Resource selection function (RSF) models were used to explain presence/absence of fish in small streams. Target species were bull trout, rainbow trout and non-native brook trout. Using GIS, the drainage network was divided into reaches with uniform slope and drainage area and then polygons for each reach were created. Predictor variables described stream size, stream energy, climate and land-use. We identified a set of candidate models and selected the best model using a standard Akaike Information Criteria approach. The best models were validated with two external data sets. Drainage area and basin slope parameters were included in all best models. This finding emphasizes the importance of controlling for the energy dimension at the basin scale in investigations into the effects of land-use on aquatic resources in this transitional landscape between the mountains and plains. The best model for bull trout indicated a relation between the presence of artificial migration barriers in downstream areas and the extirpation of the species from headwater reaches. We produced reach-scale maps by species and summarized this information within all small catchments across the 12,000 km2 study area. These maps had included three categories based on predicted probability of capture for individual reaches. The high probability category had a 78 percent accuracy for correctly predicting both fish present and fish not-present reaches. Basin scale maps highlight specific watersheds likely to support both native bull trout and invasive brook trout, while

  19. Performance prediction of four-contact vertical Hall-devices using a conformal mapping technique

    NASA Astrophysics Data System (ADS)

    Yang, Huang; Yue, Xu; Yufeng, Guo

    2015-12-01

    Instead of the conventional design with five contacts in the sensor active area, innovative vertical Hall devices (VHDs) with four contacts and six contacts are asymmetrical in structural design but symmetrical in the current flow that can be well fit for the spinning current technique for offset elimination. In this article, a conformal mapping calculation method is used to predict the performance of asymmetrical VHD embedded in a deep n-well with four contacts. Furthermore, to make the calculation more accurate, the junction field effect is also involved into the conformal mapping method. The error between calculated and simulated results is less than 5% for the current-related sensitivity, and approximately 13% for the voltage-related sensitivity. This proves that such calculations can be used to predict the optimal structure of the vertical Hall-devices. Project supported by the Natural Science Foundation of Jiangsu Province, China (Nos. BK20131379, BK20141431) and the Graduate Research and Innovation Projects of Jiangsu Province (No. SJLX_0373).

  20. Prediction-for-CompAction: navigation in social environments using generalized cognitive maps.

    PubMed

    Villacorta-Atienza, Jose A; Calvo, Carlos; Makarov, Valeri A

    2015-06-01

    The ultimate navigation efficiency of mobile robots in human environments will depend on how we will appraise them: merely as impersonal machines or as human-like agents. In the latter case, an agent may take advantage of the cooperative collision avoidance, given that it possesses recursive cognition, i.e., the agent's decisions depend on the decisions made by humans that in turn depend on the agent's decisions. To deal with this high-level cognitive skill, we propose a neural network architecture implementing Prediction-for-CompAction paradigm. The network predicts possible human-agent collisions and compacts the time dimension by projecting a given dynamic situation into a static map. Thereby emerging compact cognitive map can be readily used as a "dynamic GPS" for planning actions or mental evaluation of the convenience of cooperation in a given context. We provide numerical evidence that cooperation yields additional room for more efficient navigation in cluttered pedestrian flows, and the agent can choose path to the target significantly shorter than a robot treated by humans as a functional machine. Moreover, the navigation safety, i.e., the chances to avoid accidental collisions, increases under cooperation. Remarkably, these benefits yield no additional load to the mean society effort. Thus, the proposed strategy is socially compliant, and the humanoid agent can behave as "one of us." PMID:25677525

  1. Prediction-for-CompAction: navigation in social environments using generalized cognitive maps.

    PubMed

    Villacorta-Atienza, Jose A; Calvo, Carlos; Makarov, Valeri A

    2015-06-01

    The ultimate navigation efficiency of mobile robots in human environments will depend on how we will appraise them: merely as impersonal machines or as human-like agents. In the latter case, an agent may take advantage of the cooperative collision avoidance, given that it possesses recursive cognition, i.e., the agent's decisions depend on the decisions made by humans that in turn depend on the agent's decisions. To deal with this high-level cognitive skill, we propose a neural network architecture implementing Prediction-for-CompAction paradigm. The network predicts possible human-agent collisions and compacts the time dimension by projecting a given dynamic situation into a static map. Thereby emerging compact cognitive map can be readily used as a "dynamic GPS" for planning actions or mental evaluation of the convenience of cooperation in a given context. We provide numerical evidence that cooperation yields additional room for more efficient navigation in cluttered pedestrian flows, and the agent can choose path to the target significantly shorter than a robot treated by humans as a functional machine. Moreover, the navigation safety, i.e., the chances to avoid accidental collisions, increases under cooperation. Remarkably, these benefits yield no additional load to the mean society effort. Thus, the proposed strategy is socially compliant, and the humanoid agent can behave as "one of us."

  2. Feature maps driven no-reference image quality prediction of authentically distorted images

    NASA Astrophysics Data System (ADS)

    Ghadiyaram, Deepti; Bovik, Alan C.

    2015-03-01

    Current blind image quality prediction models rely on benchmark databases comprised of singly and synthetically distorted images, thereby learning image features that are only adequate to predict human perceived visual quality on such inauthentic distortions. However, real world images often contain complex mixtures of multiple distortions. Rather than a) discounting the effect of these mixtures of distortions on an image's perceptual quality and considering only the dominant distortion or b) using features that are only proven to be efficient for singly distorted images, we deeply study the natural scene statistics of authentically distorted images, in different color spaces and transform domains. We propose a feature-maps-driven statistical approach which avoids any latent assumptions about the type of distortion(s) contained in an image, and focuses instead on modeling the remarkable consistencies in the scene statistics of real world images in the absence of distortions. We design a deep belief network that takes model-based statistical image features derived from a very large database of authentically distorted images as input and discovers good feature representations by generalizing over different distortion types, mixtures, and severities, which are later used to learn a regressor for quality prediction. We demonstrate the remarkable competence of our features for improving automatic perceptual quality prediction on a benchmark database and on the newly designed LIVE Authentic Image Quality Challenge Database and show that our approach of combining robust statistical features and the deep belief network dramatically outperforms the state-of-the-art.

  3. Prediction of 3D chip formation in the facing cutting with lathe machine using FEM

    NASA Astrophysics Data System (ADS)

    Prasetyo, Yudhi; Tauviqirrahman, Mohamad; Rusnaldy

    2016-04-01

    This paper presents the prediction of the chip formation at the machining process using a lathe machine in a more specific way focusing on facing cutting (face turning). The main purpose is to propose a new approach to predict the chip formation with the variation of the cutting directions i.e., the backward and forward direction. In addition, the interaction between stress analysis and chip formation on cutting process was also investigated. The simulations were conducted using three dimensional (3D) finite element method based on ABAQUS software with aluminum and high speed steel (HSS) as the workpiece and the tool materials, respectively. The simulation result showed that the chip resulted using a backward direction depicts a better formation than that using a conventional (forward) direction.

  4. A Thermodynamic Approach to Predict Formation Enthalpies of Ternary Systems Based on Miedema's Model

    NASA Astrophysics Data System (ADS)

    Mousavi, Mahbubeh Sadat; Abbasi, Roozbeh; Kashani-Bozorg, Seyed Farshid

    2016-07-01

    A novel modification to the thermodynamic semi-empirical Miedema's model has been made in order to provide more precise estimations of formation enthalpy in ternary alloys. The original Miedema's model was modified for ternary systems based on surface concentration function revisions. The results predicted by the present model were found to be in excellent agreement with the available experimental data of over 150 ternary intermetallic compounds. The novel proposed model is capable of predicting formation enthalpies of ternary intermetallics with small discrepancies of ≤20 kJ/mol as well as providing reliable enthalpy variations.

  5. Mapping the formation areas of giant molybdenum blue clusters: a spectroscopic study

    SciTech Connect

    Botar, Bogdan; Ellern, Arkady; Kogerler, Paul

    2012-05-18

    The self-assembly of soluble molybdenum blue species from simple molybdate solutions has primarily been associated with giant mixed-valent wheel-shaped cluster anions, derived from the {MoV/VI154/176} archetypes, and a {MoV/VI368} lemon-shaped cluster. The combined use of Raman spectroscopy and kinetic precipitation as self-assembly monitoring techniques and single-crystal X-ray diffraction is key to mapping the realm of molybdenum blue species by establishing spherical {MoV/VI102}-type Keplerates as an important giant molybdenum blue-type species. We additionally rationalize the empirical effect of reducing agent concentration on the formation of all three relevant skeletal types: wheel, lemon and spheres. Whereas both wheels and the lemon-shaped {MoV/VI368} cluster are obtained from weakly reduced molybdenum blue solutions, considerably higher reduced solutions lead to {MoV/VI102}-type Keplerates.

  6. Dynamics of Hollow Atom Formation in Intense X-Ray Pulses Probed by Partial Covariance Mapping

    NASA Astrophysics Data System (ADS)

    Frasinski, L. J.; Zhaunerchyk, V.; Mucke, M.; Squibb, R. J.; Siano, M.; Eland, J. H. D.; Linusson, P.; v. d. Meulen, P.; Salén, P.; Thomas, R. D.; Larsson, M.; Foucar, L.; Ullrich, J.; Motomura, K.; Mondal, S.; Ueda, K.; Osipov, T.; Fang, L.; Murphy, B. F.; Berrah, N.; Bostedt, C.; Bozek, J. D.; Schorb, S.; Messerschmidt, M.; Glownia, J. M.; Cryan, J. P.; Coffee, R. N.; Takahashi, O.; Wada, S.; Piancastelli, M. N.; Richter, R.; Prince, K. C.; Feifel, R.

    2013-08-01

    When exposed to ultraintense x-radiation sources such as free electron lasers (FELs) the innermost electronic shell can efficiently be emptied, creating a transient hollow atom or molecule. Understanding the femtosecond dynamics of such systems is fundamental to achieving atomic resolution in flash diffraction imaging of noncrystallized complex biological samples. We demonstrate the capacity of a correlation method called “partial covariance mapping” to probe the electron dynamics of neon atoms exposed to intense 8 fs pulses of 1062 eV photons. A complete picture of ionization processes competing in hollow atom formation and decay is visualized with unprecedented ease and the map reveals hitherto unobserved nonlinear sequences of photoionization and Auger events. The technique is particularly well suited to the high counting rate inherent in FEL experiments.

  7. Mapping the formation areas of giant molybdenum blue clusters: a spectroscopic study.

    PubMed

    Botar, Bogdan; Ellern, Arkady; Kögerler, Paul

    2012-08-01

    The self-assembly of soluble molybdenum blue species from simple molybdate solutions has primarily been associated with giant mixed-valent wheel-shaped cluster anions, derived from the {Mo(V/VI)(154/176)} archetypes, and a {Mo(V/VI)(368)} lemon-shaped cluster. The combined use of Raman spectroscopy and kinetic precipitation as self-assembly monitoring techniques and single-crystal X-ray diffraction is key to mapping the realm of molybdenum blue species by establishing spherical {Mo(V/VI)(102)}-type Keplerates as an important giant molybdenum blue-type species. We additionally rationalize the empirical effect of reducing agent concentration on the formation of all three relevant skeletal types: wheel, lemon and spheres. Whereas both wheels and the lemon-shaped {Mo(V/VI)(368)} cluster are obtained from weakly reduced molybdenum blue solutions, considerably higher reduced solutions lead to {Mo(V/VI)(102)}-type Keplerates. PMID:22717474

  8. Mapping Soil Properties of Africa at 250 m Resolution: Random Forests Significantly Improve Current Predictions.

    PubMed

    Hengl, Tomislav; Heuvelink, Gerard B M; Kempen, Bas; Leenaars, Johan G B; Walsh, Markus G; Shepherd, Keith D; Sila, Andrew; MacMillan, Robert A; Mendes de Jesus, Jorge; Tamene, Lulseged; Tondoh, Jérôme E

    2015-01-01

    80% of arable land in Africa has low soil fertility and suffers from physical soil problems. Additionally, significant amounts of nutrients are lost every year due to unsustainable soil management practices. This is partially the result of insufficient use of soil management knowledge. To help bridge the soil information gap in Africa, the Africa Soil Information Service (AfSIS) project was established in 2008. Over the period 2008-2014, the AfSIS project compiled two point data sets: the Africa Soil Profiles (legacy) database and the AfSIS Sentinel Site database. These data sets contain over 28 thousand sampling locations and represent the most comprehensive soil sample data sets of the African continent to date. Utilizing these point data sets in combination with a large number of covariates, we have generated a series of spatial predictions of soil properties relevant to the agricultural management--organic carbon, pH, sand, silt and clay fractions, bulk density, cation-exchange capacity, total nitrogen, exchangeable acidity, Al content and exchangeable bases (Ca, K, Mg, Na). We specifically investigate differences between two predictive approaches: random forests and linear regression. Results of 5-fold cross-validation demonstrate that the random forests algorithm consistently outperforms the linear regression algorithm, with average decreases of 15-75% in Root Mean Squared Error (RMSE) across soil properties and depths. Fitting and running random forests models takes an order of magnitude more time and the modelling success is sensitive to artifacts in the input data, but as long as quality-controlled point data are provided, an increase in soil mapping accuracy can be expected. Results also indicate that globally predicted soil classes (USDA Soil Taxonomy, especially Alfisols and Mollisols) help improve continental scale soil property mapping, and are among the most important predictors. This indicates a promising potential for transferring pedological

  9. Mapping Soil Properties of Africa at 250 m Resolution: Random Forests Significantly Improve Current Predictions.

    PubMed

    Hengl, Tomislav; Heuvelink, Gerard B M; Kempen, Bas; Leenaars, Johan G B; Walsh, Markus G; Shepherd, Keith D; Sila, Andrew; MacMillan, Robert A; Mendes de Jesus, Jorge; Tamene, Lulseged; Tondoh, Jérôme E

    2015-01-01

    80% of arable land in Africa has low soil fertility and suffers from physical soil problems. Additionally, significant amounts of nutrients are lost every year due to unsustainable soil management practices. This is partially the result of insufficient use of soil management knowledge. To help bridge the soil information gap in Africa, the Africa Soil Information Service (AfSIS) project was established in 2008. Over the period 2008-2014, the AfSIS project compiled two point data sets: the Africa Soil Profiles (legacy) database and the AfSIS Sentinel Site database. These data sets contain over 28 thousand sampling locations and represent the most comprehensive soil sample data sets of the African continent to date. Utilizing these point data sets in combination with a large number of covariates, we have generated a series of spatial predictions of soil properties relevant to the agricultural management--organic carbon, pH, sand, silt and clay fractions, bulk density, cation-exchange capacity, total nitrogen, exchangeable acidity, Al content and exchangeable bases (Ca, K, Mg, Na). We specifically investigate differences between two predictive approaches: random forests and linear regression. Results of 5-fold cross-validation demonstrate that the random forests algorithm consistently outperforms the linear regression algorithm, with average decreases of 15-75% in Root Mean Squared Error (RMSE) across soil properties and depths. Fitting and running random forests models takes an order of magnitude more time and the modelling success is sensitive to artifacts in the input data, but as long as quality-controlled point data are provided, an increase in soil mapping accuracy can be expected. Results also indicate that globally predicted soil classes (USDA Soil Taxonomy, especially Alfisols and Mollisols) help improve continental scale soil property mapping, and are among the most important predictors. This indicates a promising potential for transferring pedological

  10. Mapping Soil Properties of Africa at 250 m Resolution: Random Forests Significantly Improve Current Predictions

    PubMed Central

    Hengl, Tomislav; Heuvelink, Gerard B. M.; Kempen, Bas; Leenaars, Johan G. B.; Walsh, Markus G.; Shepherd, Keith D.; Sila, Andrew; MacMillan, Robert A.; Mendes de Jesus, Jorge; Tamene, Lulseged; Tondoh, Jérôme E.

    2015-01-01

    80% of arable land in Africa has low soil fertility and suffers from physical soil problems. Additionally, significant amounts of nutrients are lost every year due to unsustainable soil management practices. This is partially the result of insufficient use of soil management knowledge. To help bridge the soil information gap in Africa, the Africa Soil Information Service (AfSIS) project was established in 2008. Over the period 2008–2014, the AfSIS project compiled two point data sets: the Africa Soil Profiles (legacy) database and the AfSIS Sentinel Site database. These data sets contain over 28 thousand sampling locations and represent the most comprehensive soil sample data sets of the African continent to date. Utilizing these point data sets in combination with a large number of covariates, we have generated a series of spatial predictions of soil properties relevant to the agricultural management—organic carbon, pH, sand, silt and clay fractions, bulk density, cation-exchange capacity, total nitrogen, exchangeable acidity, Al content and exchangeable bases (Ca, K, Mg, Na). We specifically investigate differences between two predictive approaches: random forests and linear regression. Results of 5-fold cross-validation demonstrate that the random forests algorithm consistently outperforms the linear regression algorithm, with average decreases of 15–75% in Root Mean Squared Error (RMSE) across soil properties and depths. Fitting and running random forests models takes an order of magnitude more time and the modelling success is sensitive to artifacts in the input data, but as long as quality-controlled point data are provided, an increase in soil mapping accuracy can be expected. Results also indicate that globally predicted soil classes (USDA Soil Taxonomy, especially Alfisols and Mollisols) help improve continental scale soil property mapping, and are among the most important predictors. This indicates a promising potential for transferring pedological

  11. Decoding the Formation of New Semantics: MVPA Investigation of Rapid Neocortical Plasticity during Associative Encoding through Fast Mapping

    PubMed Central

    Atir-Sharon, Tali; Gilboa, Asaf; Hazan, Hananel; Koilis, Ester; Manevitz, Larry M.

    2015-01-01

    Neocortical structures typically only support slow acquisition of declarative memory; however, learning through fast mapping may facilitate rapid learning-induced cortical plasticity and hippocampal-independent integration of novel associations into existing semantic networks. During fast mapping the meaning of new words and concepts is inferred, and durable novel associations are incidentally formed, a process thought to support early childhood's exuberant learning. The anterior temporal lobe, a cortical semantic memory hub, may critically support such learning. We investigated encoding of semantic associations through fast mapping using fMRI and multivoxel pattern analysis. Subsequent memory performance following fast mapping was more efficiently predicted using anterior temporal lobe than hippocampal voxels, while standard explicit encoding was best predicted by hippocampal activity. Searchlight algorithms revealed additional activity patterns that predicted successful fast mapping semantic learning located in lateral occipitotemporal and parietotemporal neocortex and ventrolateral prefrontal cortex. By contrast, successful explicit encoding could be classified by activity in medial and dorsolateral prefrontal and parahippocampal cortices. We propose that fast mapping promotes incidental rapid integration of new associations into existing neocortical semantic networks by activating related, nonoverlapping conceptual knowledge. In healthy adults, this is better captured by unique anterior and lateral temporal lobe activity patterns, while hippocampal involvement is less predictive of this kind of learning. PMID:26257961

  12. A Stochastic Simulation Framework for the Prediction of Strategic Noise Mapping and Occupational Noise Exposure Using the Random Walk Approach

    PubMed Central

    Haron, Zaiton; Bakar, Suhaimi Abu; Dimon, Mohamad Ngasri

    2015-01-01

    Strategic noise mapping provides important information for noise impact assessment and noise abatement. However, producing reliable strategic noise mapping in a dynamic, complex working environment is difficult. This study proposes the implementation of the random walk approach as a new stochastic technique to simulate noise mapping and to predict the noise exposure level in a workplace. A stochastic simulation framework and software, namely RW-eNMS, were developed to facilitate the random walk approach in noise mapping prediction. This framework considers the randomness and complexity of machinery operation and noise emission levels. Also, it assesses the impact of noise on the workers and the surrounding environment. For data validation, three case studies were conducted to check the accuracy of the prediction data and to determine the efficiency and effectiveness of this approach. The results showed high accuracy of prediction results together with a majority of absolute differences of less than 2 dBA; also, the predicted noise doses were mostly in the range of measurement. Therefore, the random walk approach was effective in dealing with environmental noises. It could predict strategic noise mapping to facilitate noise monitoring and noise control in the workplaces. PMID:25875019

  13. A stochastic simulation framework for the prediction of strategic noise mapping and occupational noise exposure using the random walk approach.

    PubMed

    Han, Lim Ming; Haron, Zaiton; Yahya, Khairulzan; Bakar, Suhaimi Abu; Dimon, Mohamad Ngasri

    2015-01-01

    Strategic noise mapping provides important information for noise impact assessment and noise abatement. However, producing reliable strategic noise mapping in a dynamic, complex working environment is difficult. This study proposes the implementation of the random walk approach as a new stochastic technique to simulate noise mapping and to predict the noise exposure level in a workplace. A stochastic simulation framework and software, namely RW-eNMS, were developed to facilitate the random walk approach in noise mapping prediction. This framework considers the randomness and complexity of machinery operation and noise emission levels. Also, it assesses the impact of noise on the workers and the surrounding environment. For data validation, three case studies were conducted to check the accuracy of the prediction data and to determine the efficiency and effectiveness of this approach. The results showed high accuracy of prediction results together with a majority of absolute differences of less than 2 dBA; also, the predicted noise doses were mostly in the range of measurement. Therefore, the random walk approach was effective in dealing with environmental noises. It could predict strategic noise mapping to facilitate noise monitoring and noise control in the workplaces.

  14. Mapping invasive species and spectral mixture relationships with neotropical woody formations in southeastern Brazil

    NASA Astrophysics Data System (ADS)

    Amaral, Cibele H.; Roberts, Dar A.; Almeida, Teodoro I. R.; Souza Filho, Carlos R.

    2015-10-01

    Biological invasion substantially contributes to the increasing extinction rates of native vegetative species. The remote detection and mapping of invasive species is critical for environmental monitoring. This study aims to assess the performance of a Multiple Endmember Spectral Mixture Analysis (MESMA) applied to imaging spectroscopy data for mapping Dendrocalamus sp. (bamboo) and Pinus elliottii L. (slash pine), which are invasive plant species, in a Brazilian neotropical landscape within the tropical Brazilian savanna biome. The work also investigates the spectral mixture between these exotic species and the native woody formations, including woodland savanna, submontane and alluvial seasonal semideciduous forests (SSF). Visible to Shortwave Infrared (VSWIR) imaging spectroscopy data at one-meter spatial resolution were atmospherically corrected and subset into the different spectral ranges (VIS-NIR1: 530-919 nm; and NIR2-SWIR: 1141-2352 nm). The data were further normalized via continuum removal (CR). Multiple endmember selection methods, including Interactive Endmember Selection (IES), Endmember average root mean square error (EAR), Minimum average spectral angle (MASA) and Count-based (CoB) (collectively called EMC), were employed to create endmember libraries for the targeted vegetation classes. The performance of the MESMA was assessed at the pixel and crown scales. Statistically significant differences (α = 0.05) were observed between overall accuracies that were obtained at various spectral ranges. The infrared region (IR) was critical for detecting the vegetation classes using spectral data. The invasive species endmembers exhibited spectral patterns in the IR that were not observed in the native formations. Bamboo was characterized as having a high green vegetation (GV) fraction, lower non-photosynthetic vegetation (NPV) and a low shade fraction, while pine exhibited higher NPV and shade fractions. The invasive species showed a statistically

  15. Ab initio and template-based prediction of multi-class distance maps by two-dimensional recursive neural networks

    PubMed Central

    Walsh, Ian; Baù, Davide; Martin, Alberto JM; Mooney, Catherine; Vullo, Alessandro; Pollastri, Gianluca

    2009-01-01

    Background Prediction of protein structures from their sequences is still one of the open grand challenges of computational biology. Some approaches to protein structure prediction, especially ab initio ones, rely to some extent on the prediction of residue contact maps. Residue contact map predictions have been assessed at the CASP competition for several years now. Although it has been shown that exact contact maps generally yield correct three-dimensional structures, this is true only at a relatively low resolution (3–4 Å from the native structure). Another known weakness of contact maps is that they are generally predicted ab initio, that is not exploiting information about potential homologues of known structure. Results We introduce a new class of distance restraints for protein structures: multi-class distance maps. We show that Cα trace reconstructions based on 4-class native maps are significantly better than those from residue contact maps. We then build two predictors of 4-class maps based on recursive neural networks: one ab initio, or relying on the sequence and on evolutionary information; one template-based, or in which homology information to known structures is provided as a further input. We show that virtually any level of sequence similarity to structural templates (down to less than 10%) yields more accurate 4-class maps than the ab initio predictor. We show that template-based predictions by recursive neural networks are consistently better than the best template and than a number of combinations of the best available templates. We also extract binary residue contact maps at an 8 Å threshold (as per CASP assessment) from the 4-class predictors and show that the template-based version is also more accurate than the best template and consistently better than the ab initio one, down to very low levels of sequence identity to structural templates. Furthermore, we test both ab-initio and template-based 8 Å predictions on the CASP7 targets

  16. Predicting and mapping potential Whooping Crane stopover habitat to guide site selection for wind energy projects.

    PubMed

    Belaire, J Amy; Kreakie, Betty J; Keitt, Timothy; Minor, Emily

    2014-04-01

    Migratory stopover habitats are often not part of planning for conservation or new development projects. We identified potential stopover habitats within an avian migratory flyway and demonstrated how this information can guide the site-selection process for new development. We used the random forests modeling approach to map the distribution of predicted stopover habitat for the Whooping Crane (Grus americana), an endangered species whose migratory flyway overlaps with an area where wind energy development is expected to become increasingly important. We then used this information to identify areas for potential wind power development in a U.S. state within the flyway (Nebraska) that minimize conflicts between Whooping Crane stopover habitat and the development of clean, renewable energy sources. Up to 54% of our study area was predicted to be unsuitable as Whooping Crane stopover habitat and could be considered relatively low risk for conflicts between Whooping Cranes and wind energy development. We suggest that this type of analysis be incorporated into the habitat conservation planning process in areas where incidental take permits are being considered for Whooping Cranes or other species of concern. Field surveys should always be conducted prior to construction to verify model predictions and understand baseline conditions. PMID:24372936

  17. Predicting and mapping potential Whooping Crane stopover habitat to guide site selection for wind energy projects.

    PubMed

    Belaire, J Amy; Kreakie, Betty J; Keitt, Timothy; Minor, Emily

    2014-04-01

    Migratory stopover habitats are often not part of planning for conservation or new development projects. We identified potential stopover habitats within an avian migratory flyway and demonstrated how this information can guide the site-selection process for new development. We used the random forests modeling approach to map the distribution of predicted stopover habitat for the Whooping Crane (Grus americana), an endangered species whose migratory flyway overlaps with an area where wind energy development is expected to become increasingly important. We then used this information to identify areas for potential wind power development in a U.S. state within the flyway (Nebraska) that minimize conflicts between Whooping Crane stopover habitat and the development of clean, renewable energy sources. Up to 54% of our study area was predicted to be unsuitable as Whooping Crane stopover habitat and could be considered relatively low risk for conflicts between Whooping Cranes and wind energy development. We suggest that this type of analysis be incorporated into the habitat conservation planning process in areas where incidental take permits are being considered for Whooping Cranes or other species of concern. Field surveys should always be conducted prior to construction to verify model predictions and understand baseline conditions.

  18. Predicting Ambulance Time of Arrival to the Emergency Department Using Global Positioning System and Google Maps

    PubMed Central

    Fleischman, Ross J.; Lundquist, Mark; Jui, Jonathan; Newgard, Craig D.; Warden, Craig

    2014-01-01

    Objective To derive and validate a model that accurately predicts ambulance arrival time that could be implemented as a Google Maps web application. Methods This was a retrospective study of all scene transports in Multnomah County, Oregon, from January 1 through December 31, 2008. Scene and destination hospital addresses were converted to coordinates. ArcGIS Network Analyst was used to estimate transport times based on street network speed limits. We then created a linear regression model to improve the accuracy of these street network estimates using weather, patient characteristics, use of lights and sirens, daylight, and rush-hour intervals. The model was derived from a 50% sample and validated on the remainder. Significance of the covariates was determined by p < 0.05 for a t-test of the model coefficients. Accuracy was quantified by the proportion of estimates that were within 5 minutes of the actual transport times recorded by computer-aided dispatch. We then built a Google Maps-based web application to demonstrate application in real-world EMS operations. Results There were 48,308 included transports. Street network estimates of transport time were accurate within 5 minutes of actual transport time less than 16% of the time. Actual transport times were longer during daylight and rush-hour intervals and shorter with use of lights and sirens. Age under 18 years, gender, wet weather, and trauma system entry were not significant predictors of transport time. Our model predicted arrival time within 5 minutes 73% of the time. For lights and sirens transports, accuracy was within 5 minutes 77% of the time. Accuracy was identical in the validation dataset. Lights and sirens saved an average of 3.1 minutes for transports under 8.8 minutes, and 5.3 minutes for longer transports. Conclusions An estimate of transport time based only on a street network significantly underestimated transport times. A simple model incorporating few variables can predict ambulance time of

  19. A Neural Field Model of the Somatosensory Cortex: Formation, Maintenance and Reorganization of Ordered Topographic Maps

    PubMed Central

    Detorakis, Georgios Is.; Rougier, Nicolas P.

    2012-01-01

    We investigate the formation and maintenance of ordered topographic maps in the primary somatosensory cortex as well as the reorganization of representations after sensory deprivation or cortical lesion. We consider both the critical period (postnatal) where representations are shaped and the post-critical period where representations are maintained and possibly reorganized. We hypothesize that feed-forward thalamocortical connections are an adequate site of plasticity while cortico-cortical connections are believed to drive a competitive mechanism that is critical for learning. We model a small skin patch located on the distal phalangeal surface of a digit as a set of 256 Merkel ending complexes (MEC) that feed a computational model of the primary somatosensory cortex (area 3b). This model is a two-dimensional neural field where spatially localized solutions (a.k.a. bumps) drive cortical plasticity through a Hebbian-like learning rule. Simulations explain the initial formation of ordered representations following repetitive and random stimulations of the skin patch. Skin lesions as well as cortical lesions are also studied and results confirm the possibility to reorganize representations using the same learning rule and depending on the type of the lesion. For severe lesions, the model suggests that cortico-cortical connections may play an important role in complete recovery. PMID:22808127

  20. MAPPING CHILDREN’S POLITICS: SPATIAL STORIES, DIALOGIC RELATIONS AND POLITICAL FORMATION

    PubMed Central

    Elwood, Sarah; Mitchell, Katharyne

    2015-01-01

    This article confronts a persistent challenge in research on children’s geographies and politics: the difficulty of recognizing forms of political agency and practice that by definition fall outside of existing political theory. Children are effectively “always already” positioned outside most of the structures and ideals of modernist democratic theory, such as the public sphere and abstracted notions of communicative action or “rational” speech. Recent emphases on embodied tactics of everyday life have offered important ways to recognize children’s political agency and practice. However, we argue here that a focus on spatial practices and critical knowledge alone cannot capture the full range of children’s politics, and show how representational and dialogic practices remain a critical element of their politics in everyday life. Drawing on de Certeau’s notion of spatial stories, and Bakhtin’s concept of dialogic relations, we argue that children’s representations and dialogues comprise a significant space of their political agency and formation, in which they can make and negotiate social meanings, subjectivities, and relationships. We develop these arguments with evidence from an after-school activity programme we conducted with 10–13 year olds in Seattle, Washington, in which participants explored, mapped, wrote and spoke about the spaces and experiences of their everyday lives. Within these practices, children negotiate autonomy and self-determination, and forward ideas, representations, and expressions of agreement or disagreement that are critical to their formation as political actors. PMID:25642017

  1. The star formation and AGN luminosity relation: predictions from a semi-analytical model

    NASA Astrophysics Data System (ADS)

    Gutcke, Thales A.; Fanidakis, Nikos; Macciò, Andrea V.; Lacey, Cedric

    2015-08-01

    In a universe where active galactic nucleus (AGN) feedback regulates star formation in massive galaxies, a strong correlation between these two quantities is expected. If the gas causing star formation is also responsible for feeding the central black hole, then a positive correlation is expected. If powerful AGNs are responsible for the star formation quenching, then a negative correlation is expected. Observations so far have mainly found a mild correlation or no correlation at all [i.e. a flat relation between star formation rate (SFR) and AGN luminosity], raising questions about the whole paradigm of `AGN feedback'. In this paper, we report the predictions of the GALFORM semi-analytical model, which has a very strong coupling between AGN activity and quenching of star formation. The predicted SFR-AGN luminosity correlation appears negative in the low AGN luminosity regime, where AGN feedback acts, but becomes strongly positive in the regime of the brightest AGN. Our predictions reproduce reasonably well recent observations by Rosario et al., yet there is some discrepancy in the normalization of the correlation at low luminosities and high redshifts. Though this regime could be strongly influenced by observational biases, we argue that the disagreement could be ascribed to the fact that GALFORM neglects AGN variability effects. Interestingly, the galaxies that dominate the regime where the observations imply a weak correlation are massive early-type galaxies that are subject to AGN feedback. Nevertheless, these galaxies retain high enough molecular hydrogen contents to maintain relatively high SFRs and strong infrared emission.

  2. Large-scale mapping and predictive modeling of submerged aquatic vegetation in a shallow eutrophic lake.

    PubMed

    Havens, Karl E; Harwell, Matthew C; Brady, Mark A; Sharfstein, Bruce; East, Therese L; Rodusky, Andrew J; Anson, Daniel; Maki, Ryan P

    2002-04-01

    A spatially intensive sampling program was developed for mapping the submerged aquatic vegetation (SAV) over an area of approximately 20,000 ha in a large, shallow lake in Florida, U.S. The sampling program integrates Geographic Information System (GIS) technology with traditional field sampling of SAV and has the capability of producing robust vegetation maps under a wide range of conditions, including high turbidity, variable depth (0 to 2 m), and variable sediment types. Based on sampling carried out in August-September 2000, we measured 1,050 to 4,300 ha of vascular SAV species and approximately 14,000 ha of the macroalga Chara spp. The results were similar to those reported in the early 1990s, when the last large-scale SAV sampling occurred. Occurrence of Chara was strongly associated with peat sediments, and maximal depths of occurrence varied between sediment types (mud, sand, rock, and peat). A simple model of Chara occurrence, based only on water depth, had an accuracy of 55%. It predicted occurrence of Chara over large areas where the plant actually was not found. A model based on sediment type and depth had an accuracy of 75% and produced a spatial map very similar to that based on observations. While this approach needs to be validated with independent data in order to test its general utility, we believe it may have application elsewhere. The simple modeling approach could serve as a coarse-scale tool for evaluating effects of water level management on Chara populations.

  3. Mapping Plant Interactomes Using Literature Curated and Predicted Protein–Protein Interaction Data Sets[W

    PubMed Central

    Lee, KiYoung; Thorneycroft, David; Achuthan, Premanand; Hermjakob, Henning; Ideker, Trey

    2010-01-01

    Most cellular processes are enabled by cohorts of interacting proteins that form dynamic networks within the plant proteome. The study of these networks can provide insight into protein function and provide new avenues for research. This article informs the plant science community of the currently available sources of protein interaction data and discusses how they can be useful to researchers. Using our recently curated IntAct Arabidopsis thaliana protein–protein interaction data set as an example, we discuss potentials and limitations of the plant interactomes generated to date. In addition, we present our efforts to add value to the interaction data by using them to seed a proteome-wide map of predicted protein subcellular locations. PMID:20371643

  4. Prediction of dose and field mapping around a shielded plutonium fuel fabrication glovebox

    SciTech Connect

    Strode, J.N.; Soldat, K.L.; Brackenbush, L.W.

    1984-04-25

    Westinghouse Hanford Company, as the Department of Energy's (DOE) prime contractor for the operation of the Hanford Engineering Development Laboratory (HEDL), is responsible for the development of the Secure Automated Fabrication (SAF) Line which is to be installed in the recently constructed Fuels and Materials Examination Facility (FMEF). The SAF Line will fabricate mixed-oxide (MOX) fuel pins for the Fast Flux Test Facility (FFTF) at an annual throughput rate of six (6) metric tons (MT) of MOX. The SAF Line will also demonstrate the automated manufacture of fuel pins on a production-scale. This paper describes some of the techniques used to reduce personnel exposure on the SAF Line, as well as the prediction and field mapping of doses from a shielded fuel fabrication glovebox. Tables are also presented from which exposure rate estimates can be made for plutonium recovered from fuels having different isotopic compositions as a result of varied burnup.

  5. Mapping and predicting sinkholes by integration of remote sensing and spectroscopy methods

    NASA Astrophysics Data System (ADS)

    Goldshleger, N.; Basson, U.; Azaria, I.

    2013-08-01

    The Dead Sea coastal area is exposed to the destructive process of sinkhole collapse. The increase in sinkhole activity in the last two decades has been substantial, resulting from the continuous decrease in the Dead Sea's level, with more than 1,000 sinkholes developing as a result of upper layer collapse. Large sinkholes can reach 25 m in diameter. They are concentrated mainly in clusters in several dozens of sites with different characteristics. In this research, methods for mapping, monitoring and predicting sinkholes were developed using active and passive remote-sensing methods: field spectrometer, geophysical ground penetration radar (GPR) and a frequency domain electromagnetic instrument (FDEM). The research was conducted in three stages: 1) literature review and data collection; 2) mapping regions abundant with sinkholes in various stages and regions vulnerable to sinkholes; 3) analyzing the data and translating it into cognitive and accessible scientific information. Field spectrometry enabled a comparison between the spectral signatures of soil samples collected near active or progressing sinkholes, and those collected in regions with no visual sign of sinkhole occurrence. FDEM and GPR investigations showed that electrical conductivity and soil moisture are higher in regions affected by sinkholes. Measurements taken at different time points over several seasons allowed monitoring the progress of an 'embryonic' sinkhole.

  6. Predictive Mapping of Human Risk for West Nile Virus (WNV) Based on Environmental and Socioeconomic Factors

    PubMed Central

    Rochlin, Ilia; Turbow, David; Gomez, Frank; Ninivaggi, Dominick V.; Campbell, Scott R.

    2011-01-01

    A West Nile virus (WNV) human risk map was developed for Suffolk County, New York utilizing a case-control approach to explore the association between the risk of vector-borne WNV and habitat, landscape, virus activity, and socioeconomic variables derived from publically available datasets. Results of logistic regression modeling for the time period between 2000 and 2004 revealed that higher proportion of population with college education, increased habitat fragmentation, and proximity to WNV positive mosquito pools were strongly associated with WNV human risk. Similar to previous investigations from north-central US, this study identified middle class suburban neighborhoods as the areas with the highest WNV human risk. These results contrast with similar studies from the southern and western US, where the highest WNV risk was associated with low income areas. This discrepancy may be due to regional differences in vector ecology, urban environment, or human behavior. Geographic Information Systems (GIS) analytical tools were used to integrate the risk factors in the 2000–2004 logistic regression model generating WNV human risk map. In 2005–2010, 41 out of 46 (89%) of WNV human cases occurred either inside of (30 cases) or in close proximity (11 cases) to the WNV high risk areas predicted by the 2000–2004 model. The novel approach employed by this study may be implemented by other municipal, local, or state public health agencies to improve geographic risk estimates for vector-borne diseases based on a small number of acute human cases. PMID:21853103

  7. Predictive modeling and mapping of Malayan Sun Bear (Helarctos malayanus) distribution using maximum entropy.

    PubMed

    Nazeri, Mona; Jusoff, Kamaruzaman; Madani, Nima; Mahmud, Ahmad Rodzi; Bahman, Abdul Rani; Kumar, Lalit

    2012-01-01

    One of the available tools for mapping the geographical distribution and potential suitable habitats is species distribution models. These techniques are very helpful for finding poorly known distributions of species in poorly sampled areas, such as the tropics. Maximum Entropy (MaxEnt) is a recently developed modeling method that can be successfully calibrated using a relatively small number of records. In this research, the MaxEnt model was applied to describe the distribution and identify the key factors shaping the potential distribution of the vulnerable Malayan Sun Bear (Helarctos malayanus) in one of the main remaining habitats in Peninsular Malaysia. MaxEnt results showed that even though Malaysian sun bear habitat is tied with tropical evergreen forests, it lives in a marginal threshold of bio-climatic variables. On the other hand, current protected area networks within Peninsular Malaysia do not cover most of the sun bears potential suitable habitats. Assuming that the predicted suitability map covers sun bears actual distribution, future climate change, forest degradation and illegal hunting could potentially severely affect the sun bear's population. PMID:23110182

  8. Predictive modeling of multicellular structure formation by using Cellular Particle Dynamics simulations

    NASA Astrophysics Data System (ADS)

    McCune, Matthew; Shafiee, Ashkan; Forgacs, Gabor; Kosztin, Ioan

    2014-03-01

    Cellular Particle Dynamics (CPD) is an effective computational method for describing and predicting the time evolution of biomechanical relaxation processes of multicellular systems. A typical example is the fusion of spheroidal bioink particles during post bioprinting structure formation. In CPD cells are modeled as an ensemble of cellular particles (CPs) that interact via short-range contact interactions, characterized by an attractive (adhesive interaction) and a repulsive (excluded volume interaction) component. The time evolution of the spatial conformation of the multicellular system is determined by following the trajectories of all CPs through integration of their equations of motion. CPD was successfully applied to describe and predict the fusion of 3D tissue construct involving identical spherical aggregates. Here, we demonstrate that CPD can also predict tissue formation involving uneven spherical aggregates whose volumes decrease during the fusion process. Work supported by NSF [PHY-0957914]. Computer time provided by the University of Missouri Bioinformatics Consortium.

  9. The Salient Map Analysis for Research and Teaching (SMART) method: Powerful potential as a formative assessment in the biomedical sciences

    NASA Astrophysics Data System (ADS)

    Cathcart, Laura Anne

    This dissertation consists of two studies: 1) development and characterization of the Salient Map Analysis for Research and Teaching (SMART) method as a formative assessment tool and 2) a case study exploring how a paramedic instructor's beliefs about learners affect her utilization of the SMART method and vice versa. The first study explored: How can a novel concept map analysis method be designed as an effective formative assessment tool? The SMART method improves upon existing concept map analysis methods because it does not require hierarchically structured concept maps and it preserves the rich content of the maps instead of reducing each map down to a numerical score. The SMART method is performed by comparing a set of students' maps to each other and to an instructor's map. The resulting composite map depicts, in percentages and highlighted colors, the similarities and differences between all of the maps. Some advantages of the SMART method as a formative assessment tool include its ability to highlight changes across time, problematic or alternative conceptions, and patterns of student responses at a glance. Study two explored: How do a paramedic instructor's beliefs about students and learning affect---and become affected by---her use of the SMART method as a formative assessment tool? This case study of Angel, an expert paramedic instructor, begins to address a gap in the emergency medical services (EMS) education literature, which contains almost no research on teachers or pedagogy. Angel and I worked together as participant co-researchers (Heron & Reason, 1997) exploring the affordances of the SMART method. This study, based on those interactions with Angel, involved using open coding to identify themes (Strauss & Corbin, 1998) from Angel's views of students and use of the SMART method. Angel views learning as a sense-making process. She has a multi-faceted view of her students as novices and invests substantial time trying to understand their concept

  10. New method for prediction of shale gas content in continental shale formation using well logs

    NASA Astrophysics Data System (ADS)

    Li, Sheng-Jie; Cui, Zhe; Jiang, Zhen-Xue; Shao, Yu; Liao, Wei; Li, Li

    2016-06-01

    Shale needs to contain a sufficient amount of gas to make it viable for exploitation. The continental heterogeneous shale formation in the Yan-chang (YC) area is investigated by firstly measuring the shale gas content in a laboratory and then investigating use of a theoretical prediction model. Key factors controlling the shale gas content are determined, and a prediction model for free gas content is established according to the equation of gas state and a new petrophysical volume model. Application of the Langmuir volume constant and pressure constant obtained from results of adsorption isotherms is found to be limited because these constants are greatly affected by experimental temperature and pressures. Therefore, using measurements of adsorption isotherms and thermodynamic theory, the influence of temperature, total organic carbon (TOC), and mineralogy on Langmuir volume constants and pressure constants are investigated in detail. A prediction model for the Langmuir pressure constant with a correction of temperatures is then established, and a prediction model for the Langmuir volume constant with correction of temperature, TOC, and quartz contents is also proposed. Using these corrected Langmuir constants, application of the Langmuir model determined using experimental adsorption isotherms is extrapolated to reservoir temperature, pressure, and lithological conditions, and a method for the prediction of shale gas content using well logs is established. Finally, this method is successfully applied to predict the shale gas content of the continental shale formation in the YC area, and practical application is shown to deliver good results with high precision.

  11. Surface Electrical Conductivity Prediction by Soil Moisture and Electromagnetic Mapping Techniques: Implication for Landmine Detection Technologies

    NASA Astrophysics Data System (ADS)

    Katsube, J.; McNairn, H.; Keating, P. K.; Das, Y.; Dyke, L.; Best, M. E.; Singhroy, V.; Connell-Madore, S.; Hunter, J.; Klassen, R.; Dilabio, R.; Moore, A.

    2004-05-01

    Electrical conductivity (EC) can be a source of significant signal interference in landmine detection, implying that there is a necessity for soil EC prediction in order to carry out safe demining operations in landmine affected countries in the world. A fundamental study on soil EC mechanisms and their relationship to moisture content has been carried out in order to increase the soil EC prediction accuracy when using data from various sensors, such as remote sensing, airborne and surficial electromagnetic (EM) methods. Results indicate that soil moisture consists of free water filling pore spaces and bound water which forms adsorbed water layers on the grain surfaces. The response of these two water phases to drying rates and EC are very different, to the extent that a moist clay poor soil may have low EC but a dry clay rich soil may have higher EC. This is a result of not only the bound water layers being a significant source of EC, but of the capillary component of the free water reacting differently to the different grain-sizes of the soil. The capillary water forms important electrical conductive bridges between the adsorbed water layers on the grains that constitute the soil. This implies that information on soil texture, mineralogy and their distribution are required for accurate EC prediction. Whereas information on these soil characteristics may be acquired by remote sensing and soil maps, soil moisture content is likely to vary from the time of data acquisition to that of demining operations, implying methods to predict these changes are required. In addition, soil type inhomogeniety, such as vertical and horizontal variation can also be a source of inaccuracies in moisture and EC predictions. However, these investigations also indicate that a wide band electrical frequency signal may have the possibility of providing information on, not only metallic mineral content, but on pore space, clay mineral type and water content. In addition, applications of

  12. A set of nearest neighbor parameters for predicting the enthalpy change of RNA secondary structure formation

    PubMed Central

    Lu, Zhi John; Turner, Douglas H.; Mathews, David H.

    2006-01-01

    A complete set of nearest neighbor parameters to predict the enthalpy change of RNA secondary structure formation was derived. These parameters can be used with available free energy nearest neighbor parameters to extend the secondary structure prediction of RNA sequences to temperatures other than 37°C. The parameters were tested by predicting the secondary structures of sequences with known secondary structure that are from organisms with known optimal growth temperatures. Compared with the previous set of enthalpy nearest neighbor parameters, the sensitivity of base pair prediction improved from 65.2 to 68.9% at optimal growth temperatures ranging from 10 to 60°C. Base pair probabilities were predicted with a partition function and the positive predictive value of structure prediction is 90.4% when considering the base pairs in the lowest free energy structure with pairing probability of 0.99 or above. Moreover, a strong correlation is found between the predicted melting temperatures of RNA sequences and the optimal growth temperatures of the host organism. This indicates that organisms that live at higher temperatures have evolved RNA sequences with higher melting temperatures. PMID:16982646

  13. Radiomic Texture Analysis Mapping Predicts Areas of True Functional MRI Activity.

    PubMed

    Hassan, Islam; Kotrotsou, Aikaterini; Bakhtiari, Ali Shojaee; Thomas, Ginu A; Weinberg, Jeffrey S; Kumar, Ashok J; Sawaya, Raymond; Luedi, Markus M; Zinn, Pascal O; Colen, Rivka R

    2016-01-01

    Individual analysis of functional Magnetic Resonance Imaging (fMRI) scans requires user-adjustment of the statistical threshold in order to maximize true functional activity and eliminate false positives. In this study, we propose a novel technique that uses radiomic texture analysis (TA) features associated with heterogeneity to predict areas of true functional activity. Scans of 15 right-handed healthy volunteers were analyzed using SPM8. The resulting functional maps were thresholded to optimize visualization of language areas, resulting in 116 regions of interests (ROIs). A board-certified neuroradiologist classified different ROIs into Expected (E) and Non-Expected (NE) based on their anatomical locations. TA was performed using the mean Echo-Planner Imaging (EPI) volume, and 20 rotation-invariant texture features were obtained for each ROI. Using forward stepwise logistic regression, we built a predictive model that discriminated between E and NE areas of functional activity, with a cross-validation AUC and success rate of 79.84% and 80.19% respectively (specificity/sensitivity of 78.34%/82.61%). This study found that radiomic TA of fMRI scans may allow for determination of areas of true functional activity, and thus eliminate clinician bias. PMID:27151623

  14. Radiomic Texture Analysis Mapping Predicts Areas of True Functional MRI Activity

    PubMed Central

    Hassan, Islam; Kotrotsou, Aikaterini; Bakhtiari, Ali Shojaee; Thomas, Ginu A.; Weinberg, Jeffrey S.; Kumar, Ashok J.; Sawaya, Raymond; Luedi, Markus M.; Zinn, Pascal O.; Colen, Rivka R.

    2016-01-01

    Individual analysis of functional Magnetic Resonance Imaging (fMRI) scans requires user-adjustment of the statistical threshold in order to maximize true functional activity and eliminate false positives. In this study, we propose a novel technique that uses radiomic texture analysis (TA) features associated with heterogeneity to predict areas of true functional activity. Scans of 15 right-handed healthy volunteers were analyzed using SPM8. The resulting functional maps were thresholded to optimize visualization of language areas, resulting in 116 regions of interests (ROIs). A board-certified neuroradiologist classified different ROIs into Expected (E) and Non-Expected (NE) based on their anatomical locations. TA was performed using the mean Echo-Planner Imaging (EPI) volume, and 20 rotation-invariant texture features were obtained for each ROI. Using forward stepwise logistic regression, we built a predictive model that discriminated between E and NE areas of functional activity, with a cross-validation AUC and success rate of 79.84% and 80.19% respectively (specificity/sensitivity of 78.34%/82.61%). This study found that radiomic TA of fMRI scans may allow for determination of areas of true functional activity, and thus eliminate clinician bias. PMID:27151623

  15. Mapping of Sand Types and Dune Morphologies in the Aeolis Dorsa Region, Western Medusae Fossae Formation, Mars

    NASA Astrophysics Data System (ADS)

    Boyd, A. S.; Burr, D. M.

    2016-06-01

    Preliminary mapping of low- and high-albedo sand deposits in the Aeolis Dorsa region, Medusae Fossae Formation (MFF), suggests sand transport from the north, consistent with sand source(s) in Elysium Mons, the Cerberus plains, or the MFF itself.

  16. A linkage map of maize x teosinte zea luxurians and identification of qtls controlling root aerenchyma formation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One-hundred and ninety five F2 individuals, derived from a cross between maize inbred line B73 x Zea luxurians, were subjected to a 107 SSR marker based QTL analysis for aerenchyma cell formation that covered 1,331 cM across all ten maize and Zea luxurians chromosomes. Composite interval mapping a...

  17. Predictive Mapping of Topsoil Organic Carbon in an Alpine Environment Aided by Landsat TM

    PubMed Central

    Yang, Renmin; Rossiter, David G.; Liu, Feng; Lu, Yuanyuan; Yang, Fan; Yang, Fei; Zhao, Yuguo; Li, Decheng; Zhang, Ganlin

    2015-01-01

    The objective of this study was to examine the reflectance of Landsat TM imagery for mapping soil organic Carbon (SOC) content in an Alpine environment. The studied area (ca. 3*104 km2) is the upper reaches of the Heihe River at the northeast edge of the Tibetan plateau, China. A set (105) of topsoil samples were analyzed for SOC. Boosted regression tree (BRT) models using Landsat TM imagery were built to predict SOC content, alone or with topography and climate covariates (temperature and precipitation). The best model, combining all covariates, was only marginally better than using only imagery. Imagery alone was sufficient to build a reasonable model; this was a bit better than only using topography and climate covariates. The Lin’s concordance correlation coefficient values of the imagery only model and the full model are very close, larger than the topography and climate variables based model. In the full model, SOC was mainly explained by Landsat TM imagery (65% relative importance), followed by climate variables (20%) and topography (15% of relative importance). The good results from imagery are likely due to (1) the strong dependence of SOC on native vegetation intensity in this Alpine environment; (2) the strong correlation in this environment between imagery and environmental covariables, especially elevation (corresponding to temperature), precipitation, and slope aspect. We conclude that multispectral satellite data from Landsat TM images may be used to predict topsoil SOC with reasonable accuracy in Alpine regions, and perhaps other regions covered with natural vegetation, and that adding topography and climate covariables to the satellite data can improve the predictive accuracy. PMID:26473739

  18. Comparison of Northern Ireland radon maps based on indoor radon measurements and geology with maps derived by predictive modelling of airborne radiometric and ground permeability data.

    PubMed

    Appleton, J D; Miles, J C H; Young, M

    2011-03-15

    Publicly available information about radon potential in Northern Ireland is currently based on indoor radon results averaged over 1-km grid squares, an approach that does not take into account the geological origin of the radon. This study describes a spatially more accurate estimate of the radon potential of Northern Ireland using an integrated radon potential mapping method based on indoor radon measurements and geology that was originally developed for mapping radon potential in England and Wales. A refinement of this method was also investigated using linear regression analysis of a selection of relevant airborne and soil geochemical parameters from the Tellus Project. The most significant independent variables were found to be eU, a parameter derived from airborne gamma spectrometry measurements of radon decay products in the top layer of soil and exposed bedrock, and the permeability of the ground. The radon potential map generated from the Tellus data agrees in many respects with the map based on indoor radon data and geology but there are several areas where radon potential predicted from the airborne radiometric and permeability data is substantially lower. This under-prediction could be caused by the radon concentration being lower in the top 30 cm of the soil than at greater depth, because of the loss of radon from the surface rocks and soils to air.

  19. Structural Bioinformatics-Based Prediction of Exceptional Selectivity of p38 MAP Kinase Inhibitor PH-797804

    SciTech Connect

    Xing, Li; Shieh, Huey S.; Selness, Shaun R.; Devraj, Rajesh V.; Walker, John K.; Devadas, Balekudru; Hope, Heidi R.; Compton, Robert P.; Schindler, John F.; Hirsch, Jeffrey L.; Benson, Alan G.; Kurumbail, Ravi G.; Stegeman, Roderick A.; Williams, Jennifer M.; Broadus, Richard M.; Walden, Zara; Monahan, Joseph B.; Pfizer

    2009-07-24

    PH-797804 is a diarylpyridinone inhibitor of p38{alpha} mitogen-activated protein (MAP) kinase derived from a racemic mixture as the more potent atropisomer (aS), first proposed by molecular modeling and subsequently confirmed by experiments. On the basis of structural comparison with a different biaryl pyrazole template and supported by dozens of high-resolution crystal structures of p38{alpha} inhibitor complexes, PH-797804 is predicted to possess a high level of specificity across the broad human kinase genome. We used a structural bioinformatics approach to identify two selectivity elements encoded by the TXXXG sequence motif on the p38{alpha} kinase hinge: (i) Thr106 that serves as the gatekeeper to the buried hydrophobic pocket occupied by 2,4-difluorophenyl of PH-797804 and (ii) the bidentate hydrogen bonds formed by the pyridinone moiety with the kinase hinge requiring an induced 180{sup o} rotation of the Met109-Gly110 peptide bond. The peptide flip occurs in p38{alpha} kinase due to the critical glycine residue marked by its conformational flexibility. Kinome-wide sequence mining revealed rare presentation of the selectivity motif. Corroboratively, PH-797804 exhibited exceptionally high specificity against MAP kinases and the related kinases. No cross-reactivity was observed in large panels of kinase screens (selectivity ratio of >500-fold). In cellular assays, PH-797804 demonstrated superior potency and selectivity consistent with the biochemical measurements. PH-797804 has met safety criteria in human phase I studies and is under clinical development for several inflammatory conditions. Understanding the rationale for selectivity at the molecular level helps elucidate the biological function and design of specific p38{alpha} kinase inhibitors.

  20. Potentiometric-surface map of water in the Judith River Formation in the Northern Great Plains area of Montana

    USGS Publications Warehouse

    Levings, Gary W.

    1982-01-01

    The potentiometric surface of the Judith River Formation is mapped at a scale of 1:1,000,000. The map is one of a series produced as part of a regional study of aquifers of Cenozoic and Mesozoic age in the northern Great Plains of Montana. The contour interval is 200 feet. Water in the Judith River Formation occurs under water-table and artesian conditions. The direction of regional ground-water movement is from west to east. Water is discharged from the Judith River Formation to the Milk River from near Havre, Montana, to Malta and to the Missouri River south of the Bearpaw and Little Rocky Mountains. The average discharge from 236 wells is about 10 gallons per minute, and the specific capacity of 186 wells averages 0.66 gallon per minute per foot of drawdown. (USGS)

  1. A program for the conversion of The National Map data from proprietary format to resource description framework (RDF)

    USGS Publications Warehouse

    Bulen, Andrew; Carter, Jonathan J.; Varanka, Dalia E.

    2011-01-01

    To expand data functionality and capabilities for users of The National Map of the U.S. Geological Survey, data sets for six watersheds and three urban areas were converted from the Best Practices vector data model formats to Semantic Web data formats. This report describes and documents the conver-sion process. The report begins with an introduction to basic Semantic Web standards and the background of The National Map. Data were converted from a proprietary format to Geog-raphy Markup Language to capture the geometric footprint of topographic data features. Configuration files were designed to eliminate redundancy and make the conversion more efficient. A SPARQL endpoint was established for data validation and queries. The report concludes by describing the results of the conversion.

  2. Using dose-surface maps to predict radiation-induced rectal bleeding: a neural network approach.

    PubMed

    Buettner, Florian; Gulliford, Sarah L; Webb, Steve; Partridge, Mike

    2009-09-01

    The incidence of late-toxicities after radiotherapy can be modelled based on the dose delivered to the organ under consideration. Most predictive models reduce the dose distribution to a set of dose-volume parameters and do not take the spatial distribution of the dose into account. The aim of this study was to develop a classifier predicting radiation-induced rectal bleeding using all available information on the dose to the rectal wall. The dose was projected on a two-dimensional dose-surface map (DSM) by virtual rectum-unfolding. These DSMs were used as inputs for a classification method based on locally connected neural networks. In contrast to fully connected conventional neural nets, locally connected nets take the topology of the input into account. In order to train the nets, data from 329 patients from the RT01 trial (ISRCTN 47772397) were split into ten roughly equal parts. By using nine of these parts as a training set and the remaining part as an independent test set, a ten-fold cross-validation was performed. Ensemble learning was used and 250 nets were built from randomly selected patients from the training set. Out of these 250 nets, an ensemble of expert nets was chosen. The performances of the full ensemble and of the expert ensemble were quantified by using receiver-operator-characteristic (ROC) curves. In order to quantify the predictive power of the shape, ensembles of fully connected conventional neural nets based on dose-surface histograms (DSHs) were generated and their performances were quantified. The expert ensembles performed better than or equally as well as the full ensembles. The area under the ROC curve for the DSM-based expert ensemble was 0.64. The area under the ROC curve for the DSH-based expert ensemble equalled 0.59. This difference in performance indicates that not only volumetric, but also morphological aspects of the dose distribution are correlated to rectal bleeding after radiotherapy. Thus, the shape of the dose

  3. Factors affecting paddy soil arsenic concentration in Bangladesh: prediction and uncertainty of geostatistical risk mapping.

    PubMed

    Ahmed, Zia U; Panaullah, Golam M; DeGloria, Stephen D; Duxbury, John M

    2011-12-15

    Knowledge of the spatial correlation of soil arsenic (As) concentrations with environmental variables is needed to assess the nature and extent of the risk of As contamination from irrigation water in Bangladesh. We analyzed 263 paired groundwater and paddy soil samples covering highland (HL) and medium highland-1 (MHL-1) land types for geostatistical mapping of soil As and delineation of As contaminated areas in Tala Upazilla, Satkhira district. We also collected 74 non-rice soil samples to assess the baseline concentration of soil As for this area. The mean soil As concentrations (mg/kg) for different land types under rice and non-rice crops were: rice-MHL-1 (21.2)>rice-HL (14.1)>non-rice-MHL-1 (11.9)>non-rice-HL (7.2). Multiple regression analyses showed that irrigation water As, Fe, land elevation and years of tubewell operation are the important factors affecting the concentrations of As in HL paddy soils. Only years of tubewell operation affected As concentration in the MHL-1 paddy soils. Quantitatively similar increases in soil As above the estimated baseline-As concentration were observed for rice soils on HL and MHL-1 after 6-8 years of groundwater irrigation, implying strong retention of As added in irrigation water in both land types. Application of single geostatistical methods with secondary variables such as regression kriging (RK) and ordinary co-kriging (OCK) gave little improvement in prediction of soil As over ordinary kriging (OK). Comparing single prediction methods, kriging within strata (KWS), the combination of RK for HL and OCK for MHL-1, gave more accurate soil As predictions and showed the lowest misclassification of declaring a location "contaminated" with respect to 14.8 mg As/kg, the highest value obtained for the baseline soil As concentration. Prediction of soil As buildup over time indicated that 75% or the soils cropped to rice would contain at least 30 mg/L As by the year 2020. PMID:22055452

  4. Factors affecting paddy soil arsenic concentration in Bangladesh: prediction and uncertainty of geostatistical risk mapping.

    PubMed

    Ahmed, Zia U; Panaullah, Golam M; DeGloria, Stephen D; Duxbury, John M

    2011-12-15

    Knowledge of the spatial correlation of soil arsenic (As) concentrations with environmental variables is needed to assess the nature and extent of the risk of As contamination from irrigation water in Bangladesh. We analyzed 263 paired groundwater and paddy soil samples covering highland (HL) and medium highland-1 (MHL-1) land types for geostatistical mapping of soil As and delineation of As contaminated areas in Tala Upazilla, Satkhira district. We also collected 74 non-rice soil samples to assess the baseline concentration of soil As for this area. The mean soil As concentrations (mg/kg) for different land types under rice and non-rice crops were: rice-MHL-1 (21.2)>rice-HL (14.1)>non-rice-MHL-1 (11.9)>non-rice-HL (7.2). Multiple regression analyses showed that irrigation water As, Fe, land elevation and years of tubewell operation are the important factors affecting the concentrations of As in HL paddy soils. Only years of tubewell operation affected As concentration in the MHL-1 paddy soils. Quantitatively similar increases in soil As above the estimated baseline-As concentration were observed for rice soils on HL and MHL-1 after 6-8 years of groundwater irrigation, implying strong retention of As added in irrigation water in both land types. Application of single geostatistical methods with secondary variables such as regression kriging (RK) and ordinary co-kriging (OCK) gave little improvement in prediction of soil As over ordinary kriging (OK). Comparing single prediction methods, kriging within strata (KWS), the combination of RK for HL and OCK for MHL-1, gave more accurate soil As predictions and showed the lowest misclassification of declaring a location "contaminated" with respect to 14.8 mg As/kg, the highest value obtained for the baseline soil As concentration. Prediction of soil As buildup over time indicated that 75% or the soils cropped to rice would contain at least 30 mg/L As by the year 2020.

  5. Using dose-surface maps to predict radiation-induced rectal bleeding: a neural network approach

    NASA Astrophysics Data System (ADS)

    Buettner, Florian; Gulliford, Sarah L.; Webb, Steve; Partridge, Mike

    2009-09-01

    The incidence of late-toxicities after radiotherapy can be modelled based on the dose delivered to the organ under consideration. Most predictive models reduce the dose distribution to a set of dose-volume parameters and do not take the spatial distribution of the dose into account. The aim of this study was to develop a classifier predicting radiation-induced rectal bleeding using all available information on the dose to the rectal wall. The dose was projected on a two-dimensional dose-surface map (DSM) by virtual rectum-unfolding. These DSMs were used as inputs for a classification method based on locally connected neural networks. In contrast to fully connected conventional neural nets, locally connected nets take the topology of the input into account. In order to train the nets, data from 329 patients from the RT01 trial (ISRCTN 47772397) were split into ten roughly equal parts. By using nine of these parts as a training set and the remaining part as an independent test set, a ten-fold cross-validation was performed. Ensemble learning was used and 250 nets were built from randomly selected patients from the training set. Out of these 250 nets, an ensemble of expert nets was chosen. The performances of the full ensemble and of the expert ensemble were quantified by using receiver-operator-characteristic (ROC) curves. In order to quantify the predictive power of the shape, ensembles of fully connected conventional neural nets based on dose-surface histograms (DSHs) were generated and their performances were quantified. The expert ensembles performed better than or equally as well as the full ensembles. The area under the ROC curve for the DSM-based expert ensemble was 0.64. The area under the ROC curve for the DSH-based expert ensemble equalled 0.59. This difference in performance indicates that not only volumetric, but also morphological aspects of the dose distribution are correlated to rectal bleeding after radiotherapy. Thus, the shape of the dose

  6. Maps showing formation temperatures and configurations of the tops of the Minnelusa Formation and the Madison Limestone, Powder River basin, Wyoming, Montana, and adjacent areas

    USGS Publications Warehouse

    Head, William J.; Kilty, Kevin Thomas; Knottek, Richard K.

    1978-01-01

    This report is part of a study to describe the hydrogeologic framework needed to evaluate the water resources of the Paleozoic age aquifers in the Northern Great Plains coal region. Preliminary studies by the U.S. Geological Survey and State agencies in Wyoming, Montana, and South Dakota have indicated that these aquifers might provide a significant percentage of the water requirements for coal development. Geologic and water-temperature data for the Minnelusa Formation of Permian and Pennsylvanian age and for the Madison Limestone (Group where it is subdivided) of Mississippian and locally late Devonian age , and their equivalents, were compiled and interpreted. Maps were produced showing the altitude and ground-water temperatures of the top of these formations. The altitude (configuration) maps show the depth and position of the formations throughout the area. Temperature maps can be used to calculate changes in the viscosity of water caused by large temperature differences. The viscosity differences will be useful in adjusting calculated transmissivity aquifer values (the rate at which water can be transmitted through an aquifer). (Woodard-USGS)

  7. Predictions of ΛCDM eulerian hydrodynamic simulations on galaxy formation and evolution

    NASA Astrophysics Data System (ADS)

    Nagamine, Kentaro

    2001-10-01

    The purpose of this thesis is to investigate the validity of the cold dark matter (CDM) model by comparing the predictions of large-scale hydrodynamic simulations with variety of available astronomical data on galaxies. The simulations we use include a heuristic star formation recipe which allows us to study galaxy formation without making any ad hoc assumptions on the bias of galaxy distribution relative to underlying dark matter distribution. Our simulation also have additional unique features of self-consistent treatment of supernovae feedback, ultra-violet radiation field, radiation shielding, metal enrichment and metal cooling. Furthermore, a population synthesis model is used to make predictions in terms of observable light. Firstly, we discuss star formation history, stellar metallicity distribution, mass function, luminosity function, and colors of galaxies in a ΛCDM universe, both in the local universe and as functions of time. Secondly, we study the evolution of Lyman Break Galaxies at redshift 3, with particular emphasis on their star formation history, merger history, and metallicity distribution. Finally, the cosmic Mach number and its environmental dependence on overdensity and galaxy mass and age is studied. The overall picture is that there is an impressive, though imperfect match between theory, numerical simulations, and observations.

  8. Pattern formation in a model for mountain pine beetle dispersal: linking model predictions to data.

    PubMed

    Strohm, S; Tyson, R C; Powell, J A

    2013-10-01

    Pattern formation occurs in a wide range of biological systems. This pattern formation can occur in mathematical models because of diffusion-driven instability or due to the interaction between reaction, diffusion, and chemotaxis. In this paper, we investigate the spatial pattern formation of attack clusters in a system for Mountain Pine Beetle. The pattern formation (aggregation) of the Mountain Pine Beetle in order to attack susceptible trees is crucial for their survival and reproduction. We use a reaction-diffusion equation with chemotaxis to model the interaction between Mountain Pine Beetle, Mountain Pine Beetle pheromones, and susceptible trees. Mathematical analysis is utilized to discover the spacing in-between beetle attacks on the susceptible landscape. The model predictions are verified by analysing aerial detection survey data of Mountain Pine Beetle Attack from the Sawtooth National Recreation Area. We find that the distance between Mountain Pine Beetle attack clusters predicted by our model closely corresponds to the observed attack data in the Sawtooth National Recreation Area. These results clarify the spatial mechanisms controlling the transition from incipient to epidemic populations and may lead to control measures which protect forests from Mountain Pine Beetle outbreak.

  9. Geologic Mapping of the Medusae Fossae Formation on Mars (MC-8 SE and MC-23 NW) and the Northern Lowlands of Venus (V-16 and V-15)

    NASA Technical Reports Server (NTRS)

    Zimbelman, J. R.

    2008-01-01

    This report summarizes the status of a mapping project supported by NASA grant NNX07AP42G, funding for which became available on July 18, focusing on the mapping of the Medusae Fossae Formation (MFF) on Mars. The report also briefly discusses the status of maps of Venus and Ascraeus Mons, begun under previous NASA grants but which are still in progress.

  10. Predicting total organic halide formation from drinking water chlorination using quantitative structure-property relationships.

    PubMed

    Luilo, G B; Cabaniss, S E

    2011-10-01

    Chlorinating water which contains dissolved organic matter (DOM) produces disinfection byproducts, the majority of unknown structure. Hence, the total organic halide (TOX) measurement is used as a surrogate for toxic disinfection byproducts. This work derives a robust quantitative structure-property relationship (QSPR) for predicting the TOX formation potential of model compounds. Literature data for 49 compounds were used to train the QSPR in moles of chlorine per mole of compound (Cp) (mol-Cl/mol-Cp). The resulting QSPR has four descriptors, calibration [Formula: see text] of 0.72 and standard deviation of estimation of 0.43 mol-Cl/mol-Cp. Internal and external validation indicate that the QSPR has good predictive power and low bias (‰<‰1%). Applying this QSPR to predict TOX formation by DOM surrogates - tannic acid, two model fulvic acids and two agent-based model assemblages - gave a predicted TOX range of 136-184 µg-Cl/mg-C, consistent with experimental data for DOM, which ranged from 78 to 192 µg-Cl/mg-C. However, the limited structural variation in the training data may limit QSPR applicability; studies of more sulfur-containing compounds, heterocyclic compounds and high molecular weight compounds could lead to a more widely applicable QSPR.

  11. Using self-organizing maps to determine observation threshold limit predictions in highly variant data

    USGS Publications Warehouse

    Paganoni, C.A.; Chang, K.C.; Robblee, M.B.

    2006-01-01

    A significant data quality challenge for highly variant systems surrounds the limited ability to quantify operationally reasonable limits on the data elements being collected and provide reasonable threshold predictions. In many instances, the number of influences that drive a resulting value or operational range is too large to enable physical sampling for each influencer, or is too complicated to accurately model in an explicit simulation. An alternative method to determine reasonable observation thresholds is to employ an automation algorithm that would emulate a human analyst visually inspecting data for limits. Using the visualization technique of self-organizing maps (SOM) on data having poorly understood relationships, a methodology for determining threshold limits was developed. To illustrate this approach, analysis of environmental influences that drive the abundance of a target indicator species (the pink shrimp, Farfantepenaeus duorarum) provided a real example of applicability. The relationship between salinity and temperature and abundance of F. duorarum is well documented, but the effect of changes in water quality upstream on pink shrimp abundance is not well understood. The highly variant nature surrounding catch of a specific number of organisms in the wild, and the data available from up-stream hydrology measures for salinity and temperature, made this an ideal candidate for the approach to provide a determination about the influence of changes in hydrology on populations of organisms.

  12. Mapping and prediction of coal workers' pneumoconiosis with bioavailable iron content in the bituminous coals

    SciTech Connect

    Huang, X.; Li, W.H.; Attfield, M.D.; Nadas, A.; Frenkel, K.; Finkelman, R.B.

    2005-08-01

    Based on the first National Study of Coal Workers' Pneumoconiosis (CWP) and the U.S. Geological Survey database of coal quality, we show that the prevalence of CXXT in seven coal mine regions correlates with levels of bioavailable iron (BAI) in the coals from that particular region (correlation coefficient r = 0.94, p {lt} 0.0015). CWP prevalence is also correlated with contents of pyritic sulfur (r = 0.91, p {lt} 0.0048) or total iron (r = 0.85, p {lt} 0.016) but not with coal rank (r = 0.59, p {lt} 0.16) or silica (r = 0.28, p {lt} 0.54). BAI was calculated using our model, taking into account chemical interactions of pyrite, sulfuric acid, calcite, and total iron. That is, iron present in coals can become bioavailable by pyrite oxidation, which produces ferrous sulfate and sulfuric acid. Calcite is the major component in coals that neutralizes the available acid and inhibits iron's bioavailability. Therefore, levels of BAI in the coals are determined by the available amounts of acid after neutralization of calcite and the amount of total iron in the coals. Using the linear fit of CWP prevalence and the calculated BAI in the seven coal mine regions, we have derived and mapped the pneumoconiotic potencies of 7,000 coal samples. Our studies indicate that levels of BAI in the coals may be used to predict coal's toxicity, even before large-scale mining.

  13. Event-related potentials during word mapping to object shape predict toddlers' vocabulary size

    PubMed Central

    Borgström, Kristina; Torkildsen, Janne von Koss; Lindgren, Magnus

    2015-01-01

    What role does attention to different object properties play in early vocabulary development? This longitudinal study using event-related potentials in combination with behavioral measures investigated 20- and 24-month-olds' (n = 38; n = 34; overlapping n = 24) ability to use object shape and object part information in word-object mapping. The N400 component was used to measure semantic priming by images containing shape or detail information. At 20 months, the N400 to words primed by object shape varied in topography and amplitude depending on vocabulary size, and these differences predicted productive vocabulary size at 24 months. At 24 months, when most of the children had vocabularies of several hundred words, the relation between vocabulary size and the N400 effect in a shape context was weaker. Detached object parts did not function as word primes regardless of age or vocabulary size, although the part-objects were identified behaviorally. The behavioral measure, however, also showed relatively poor recognition of the part-objects compared to the shape-objects. These three findings provide new support for the link between shape recognition and early vocabulary development. PMID:25762957

  14. Microsatellite resources for Passeridae species: a predicted microsatellite map of the house sparrow Passer domesticus.

    PubMed

    Dawson, Deborah A; Horsburgh, Gavin J; Krupa, Andrew P; Stewart, Ian R K; Skjelseth, Sigrun; Jensen, Henrik; Ball, Alexander D; Spurgin, Lewis G; Mannarelli, Maria-Elena; Nakagawa, Shinichi; Schroeder, Julia; Vangestel, Carl; Hinten, Gavin N; Burke, Terry

    2012-05-01

    We identified microsatellite sequences of potential utility in the house sparrow (Passer domesticus) and assigned their predicted genome locations. These sequences included newly isolated house sparrow loci, which we fully characterized. Many of the newly isolated loci were polymorphic in two other species of Passeridae: Berthelot's pipit Anthus berthelotii and zebra finch Taeniopygia guttata. In total, we identified 179 microsatellite markers that were either isolated directly from, or are of known utility in, the house sparrow. Sixty-seven of these markers were designed from unique sequences that we isolated from a house sparrow genomic library. These new markers were combined with 36 house sparrow markers isolated by other studies and 76 markers isolated from other passerine species but known to be polymorphic in the house sparrow. We utilized sequence homology to assign chromosomal locations for these loci in the assembled zebra finch genome. One hundred and thirty-four loci were assigned to 25 different autosomes and eight loci to the Z chromosome. Examination of the genotypes of known-sex house sparrows for 37 of the new loci revealed a W-linked locus and an additional Z-linked locus. Locus Pdoμ2, previously reported as autosomal, was found to be Z-linked. These loci enable the creation of powerful and cost-effective house sparrow multiplex primer sets for population and parentage studies. They can be used to create a house sparrow linkage map and will aid the identification of quantitative trait loci in passerine species. PMID:22321340

  15. Mapping and prediction of Coal Workers' Pneumoconiosis with bioavailable iron content in the bituminous coals

    USGS Publications Warehouse

    Huang, X.; Li, W.; Attfield, M.D.; Nadas, A.; Frenkel, K.; Finkelman, R.B.

    2005-01-01

    Based on the first National Study of Coal Workers' Pneumoconiosis (CWP) and the U.S. Geological Survey database of coal quality, we show that the prevalence of CWP in seven coal mine regions correlates with levels of bioavailable iron (BAI) in the coals from that particular region (correlation coefficient r = 0.94, p < 0.0015). CWP prevalence is also correlated with contents of pyritic sulfur (r = 0.91, p < 0.0048) or total iron (r = 0.85, p < 0.016) but not with coal rank (r = 0.59, p < 0.16) or silica (r = 0.28, p < 0.54). BAI was calculated using our model, taking into account chemical interactions of pyrite, sulfuric acid, calcite, and total iron. That is, iron present in coals can become bioavailable by pyrite oxidation, which produces ferrous sulfate and sulfuric acid. Calcite is the major component in coals that neutralizes the available acid and inhibits iron's bioavailabiity. Therefore, levels of BAI in the coals are determined by the available amounts of acid after neutralization of calcite and the amount of total iron in the coals. Using the linear fit of CWP prevalence and the calculated BAI in the seven coal mine regions, we have derived and mapped the pneumoconiotic potencies of 7,000 coal samples. Our studies indicate that levels of BAI in the coals may be used to predict coal's toxicity, even before large-scalen mining.

  16. Event-related potentials during word mapping to object shape predict toddlers' vocabulary size.

    PubMed

    Borgström, Kristina; Torkildsen, Janne von Koss; Lindgren, Magnus

    2015-01-01

    What role does attention to different object properties play in early vocabulary development? This longitudinal study using event-related potentials in combination with behavioral measures investigated 20- and 24-month-olds' (n = 38; n = 34; overlapping n = 24) ability to use object shape and object part information in word-object mapping. The N400 component was used to measure semantic priming by images containing shape or detail information. At 20 months, the N400 to words primed by object shape varied in topography and amplitude depending on vocabulary size, and these differences predicted productive vocabulary size at 24 months. At 24 months, when most of the children had vocabularies of several hundred words, the relation between vocabulary size and the N400 effect in a shape context was weaker. Detached object parts did not function as word primes regardless of age or vocabulary size, although the part-objects were identified behaviorally. The behavioral measure, however, also showed relatively poor recognition of the part-objects compared to the shape-objects. These three findings provide new support for the link between shape recognition and early vocabulary development.

  17. Mapping Medusae Fossae Formation materials in the southern highlands of Mars

    NASA Astrophysics Data System (ADS)

    Harrison, S. K.; Balme, M. R.; Hagermann, A.; Murray, J. B.; Muller, J.-P.

    2010-10-01

    The Medusae Fossae Formation (MFF) is an extensive deposit (2.2 × 10 6 km 2, Bradley, B.A., Sakimoto, S.E.H., Frey, H., Zimbelman, J.R. [2002]. J. Geophys. Res. 107, 5058) of wind-eroded material of widely debated origin, which unconformably overlies a considerable area of the crustal dichotomy boundary on Mars. The MFF shows a variety of layering patterns, erosional styles and channel-like forms and has been mapped into five main outcrops and three geological members according to exposure and stratigraphy (Scott, D.H., Tanaka, K.L., 1986. USGS Map I-1802-A; Greeley, R., Guest, J.E., 1987. Map I-1802-B; Zimbelman, J.R., Crown, D., Jenson, D., 1996. Lunar Planet. Sci. XXVII. Abstract #1748.). Away from the three main lobes are numerous outliers of MFF materials. These have mainly been reported in the northern lowlands regions (Keszthelyi, L., Jaeger, W.L., and HiRISE team, 2008. Lunar Planet. Sci. XXXIX. Abstract #2420.) but few studies have examined the possibility of MFF outliers on high ground south of the dichotomy boundary. We have searched Mars Orbiter Camera Narrow Angle (MOC NA) images for outliers in this region. Our observations show that there are many MFF outliers on the southern highlands. The characteristics of the outliers indicate materials which overlie the underlying terrain for they appear widely in dips, craters and topographic lows. The surfaces are typified by yardang fields and have a similar patchy and discontinuous nature to materials of the upper member of the MFF. Most have consistent lineation orientations across the wider area which match the dominant orientation of yardangs in the main MFF outcrops. Furthermore, elevation data shows that the maximum, minimum and mean elevations of these newly discovered outliers are closest to those of the upper member of the MFF. We therefore conclude that these deposits are MFF outliers and that they probably represent remnant upper member material. We suggest that there might be two possible

  18. First USGS urban seismic hazard maps predict the effects of soils

    USGS Publications Warehouse

    Cramer, C.H.; Gomberg, J.S.; Schweig, E.S.; Waldron, B.A.; Tucker, K.

    2006-01-01

    Probabilistic and scenario urban seismic hazard maps have been produced for Memphis, Shelby County, Tennessee covering a six-quadrangle area of the city. The nine probabilistic maps are for peak ground acceleration and 0.2 s and 1.0 s spectral acceleration and for 10%, 5%, and 2% probability of being exceeded in 50 years. Six scenario maps for these three ground motions have also been generated for both an M7.7 and M6.2 on the southwest arm of the New Madrid seismic zone ending at Marked Tree, Arkansas. All maps include the effect of local geology. Relative to the national seismic hazard maps, the effect of the thick sediments beneath Memphis is to decrease 0.2 s probabilistic ground motions by 0-30% and increase 1.0 s probabilistic ground motions by ???100%. Probabilistic peak ground accelerations remain at levels similar to the national maps, although the ground motion gradient across Shelby County is reduced and ground motions are more uniform within the county. The M7.7 scenario maps show ground motions similar to the 5%-in-50-year probabilistic maps. As an effect of local geology, both M7.7 and M6.2 scenario maps show a more uniform seismic ground-motion hazard across Shelby County than scenario maps with constant site conditions (i.e., NEHRP B/C boundary).

  19. Regional scale soil thickness prediction using digital terrain modeling and seismic data: application to erosion hazard mapping.

    NASA Astrophysics Data System (ADS)

    Rochat, A.; Grandjean, G.; Cerdan, O.; Samyn, K.

    2012-04-01

    Empirical laws derived from terrain parameters - such as DTM - and calibrated with in-situ borehole data are widely used for mapping soil thickness at regional scale. But with this approach, economical and practical constrains due to drilling requires to work on limited area (typically a few ten km2). Yet, seismic methods using surface waves, recently used for subsurface issue, showed a great interest for measuring soil thickness along profiles or in 3D (parcel mapping) which is more convenient for spacializing using empirical law calibration. Thus, to accurately map soil thickness over a 400km2 large area, we suggest to match measurement provided by SASW method (spectral analysis of surface waves) with an empirical law derived from terrain attributes. For this study, S-waves velocity has been measured along 10 profiles and after calibration with penetrometrics sounding, the value Vs=300 m/s was considered as a threshold between fertile soil (loess) and consolidated material (clay) leading to define the soil thickness. Comparison between measured soil thickness and the empirical index related to soil depth has shown significant results (R2=0.58). After index calibration, soil thickness was mapped over the catchment basin using a regression law between soil depth index and measured thickness. Finally, the French soil databank (BSS®) was used for the map validation: loess depths reported by geotechnical interpretation (drilling and sounding from BSS®) fit closely to depths predicted by the thickness map. The test zone was located within the Cailly Aubette-Robec catchment area, in the Northern part of France. The region has the particularity to be severely affected by erosion processes with dramatic farming issues. So, to valorize this soil thickness mapping methodology, results were exploited in term of erosion hazard characterization by coupling the thickness map with a soil loss rate map (in t/ha/year), leading to provide temporal information about erosion

  20. Multispectral Thermal Imagery and Its Application to the Geologic Mapping of the Koobi Fora Formation, Northwestern Kenya

    SciTech Connect

    Green, Mary K.

    2005-12-01

    The Koobi Fora Formation in northwestern Kenya has yielded more hominin fossils dated between 2.1 and 1.2 Ma than any other location on Earth. This research was undertaken to discover the spectral signatures of a portion of the Koobi Fora Formation using imagery from the DOE's Multispectral Thermal Imager (MTI) satellite. Creation of a digital geologic map from MTI imagery was a secondary goal of this research. MTI is unique amongst multispectral satellites in that it co-collects data from 15 spectral bands ranging from the visible to the thermal infrared with a ground sample distance of 5 meters per pixel in the visible and 20 meters in the infrared. The map was created in two stages. The first was to correct the base MTI image using spatial accuracy assessment points collected in the field. The second was to mosaic various MTI images together to create the final Koobi Fora map. Absolute spatial accuracy of the final map product is 73 meters. The geologic classification of the Koobi Fora MTI map also took place in two stages. The field work stage involved location of outcrops of different lithologies within the Koobi Fora Formation. Field descriptions of these outcrops were made and their locations recorded. During the second stage, a linear spectral unmixing algorithm was applied to the MTI mosaic. In order to train the linear spectra unmixing algorithm, regions of interest representing four different classes of geologic material (tuff, alluvium, carbonate, and basalt), as well as a vegetation class were defined within the MTI mosaic. The regions of interest were based upon the aforementioned field data as well as overlays of geologic maps from the 1976 Iowa State mapping project. Pure spectra were generated for each class from the regions of interest, and then the unmixing algorithm classified each pixel according to relative percentage of classes found within the pixel based upon the pure spectra values. A total of four unique combinations of geologic classes

  1. Predictive Malaria Risk and Uncertainty Mapping in Nchelenge District, Zambia: Evidence of Widespread, Persistent Risk and Implications for Targeted Interventions.

    PubMed

    Pinchoff, Jessie; Chaponda, Mike; Shields, Timothy; Lupiya, James; Kobayashi, Tamaki; Mulenga, Modest; Moss, William J; Curriero, Frank C

    2015-12-01

    Malaria risk maps may be used to guide policy decisions on whether vector control interventions should be targeted and, if so, where. Active surveillance for malaria was conducted through household surveys in Nchelenge District, Zambia from April 2012 through December 2014. Households were enumerated based on satellite imagery and randomly selected for study enrollment. At each visit, participants were administered a questionnaire and a malaria rapid diagnostic test (RDT). Logistic regression models were used to construct spatial prediction risk maps and maps of risk uncertainty. A total of 461 households were visited, comprising 1,725 participants, of whom 48% were RDT positive. Several environmental features were associated with increased household malaria risk in a multivariable logistic regression model adjusting for seasonal variation. The model was validated using both internal and external evaluation measures to generate and assess root mean square error, as well as sensitivity and specificity for predicted risk. The final, validated model was used to predict and map malaria risk including a measure of risk uncertainty. Malaria risk in a high, perennial transmission setting is widespread but heterogeneous at a local scale, with seasonal variation. Targeting malaria control interventions may not be appropriate in this epidemiological setting.

  2. The Art of Teaching Map and Compass: Instructional Techniques, Curricular Formats and Practical Field Exercises.

    ERIC Educational Resources Information Center

    Watters, Ron

    This paper discusses the value of teaching map and compass skills in the classroom or an outdoor situation. Navigation is the most basic of all outdoor skills. A map and compass curriculum can be taught to anyone, is inexpensive, and is easily incorporated in a variety of educational situations. General teaching principles are outlined: (1) start…

  3. Subpixel mapping on remote sensing imagery using a prediction model combining wavelet transform and radial basis function neural network

    NASA Astrophysics Data System (ADS)

    Dai, Xiaoyan; Guo, Zhongyang; Zhang, Liquan; Xu, Wencheng

    2009-12-01

    Soft classification methods can be used for mixed-pixel classification on remote sensing imagery by estimating different land cover class fractions of every pixel. However, the spatial distribution and location of these class components within the pixel remain unknown. To map land cover at subpixel scale and increase the spatial resolution of land cover classification maps, in this paper, a prediction model combining wavelet transform and Radial Basis Functions (RBF) neural network, abbreviated as Wavelet-RBFNN, is constructed by predicting high-frequency wavelet coefficients from low-frequency coefficients at the same resolution with RBF network and taking wavelet coefficients at coarser resolution as training samples. According to different land cover class fraction images obtained from mixed-pixel classification, based on the assumption of neighborhood dependence of wavelet coefficients, subpixel mapping on remote sensing imagery can be accomplished through two steps, i.e., prediction of land cover class compositions within subpixels and hard classification. The experimental results obtained with artificial images, QuickBird image and Landsat 7 ETM+ image indicate that the subpixel mapping method proposed in this paper can successfully produce super-resolution land cover classification maps from remote sensing imagery, outperforming cubic B-spline and Kriging interpolation method in visual effect and prediction accuracy. The Wavelet-RBFNN model can also be applied to simulate higher spatial resolution image, and automatically identify and locate land cover targets at the subpixel scales, when the cost and availability of high resolution imagery prohibit its use in many areas of work.

  4. Spatial epidemiological techniques in cholera mapping and analysis towards a local scale predictive modelling

    NASA Astrophysics Data System (ADS)

    Rasam, A. R. A.; Ghazali, R.; Noor, A. M. M.; Mohd, W. M. N. W.; Hamid, J. R. A.; Bazlan, M. J.; Ahmad, N.

    2014-02-01

    Cholera spatial epidemiology is the study of the spread and control of the disease spatial pattern and epidemics. Previous studies have shown that multi-factorial causation such as human behaviour, ecology and other infectious risk factors influence the disease outbreaks. Thus, understanding spatial pattern and possible interrelationship factors of the outbreaks are crucial to be explored an in-depth study. This study focuses on the integration of geographical information system (GIS) and epidemiological techniques in exploratory analyzing the cholera spatial pattern and distribution in the selected district of Sabah. Spatial Statistic and Pattern tools in ArcGIS and Microsoft Excel software were utilized to map and analyze the reported cholera cases and other data used. Meanwhile, cohort study in epidemiological technique was applied to investigate multiple outcomes of the disease exposure. The general spatial pattern of cholera was highly clustered showed the disease spread easily at a place or person to others especially 1500 meters from the infected person and locations. Although the cholera outbreaks in the districts are not critical, it could be endemic at the crowded areas, unhygienic environment, and close to contaminated water. It was also strongly believed that the coastal water of the study areas has possible relationship with the cholera transmission and phytoplankton bloom since the areas recorded higher cases. GIS demonstrates a vital spatial epidemiological technique in determining the distribution pattern and elucidating the hypotheses generating of the disease. The next research would be applying some advanced geo-analysis methods and other disease risk factors for producing a significant a local scale predictive risk model of the disease in Malaysia.

  5. Prediction of subsidence: Relationship between lowering of formation pressure and subsidence due to fluid withdrawal

    SciTech Connect

    Serebryakov, V.A.; Chilingar, G.V.

    2000-06-01

    Abnormally low formation pressures develop in petroleum reservoirs during intensive oil and gas production or in aquifers as a result of water extraction. A simple method is presented for calculating (predicting) the amount of compaction (and resulting subsidence) from the pressure drop in formation due to production, i.e., the increase in the effective pressure p{sub e} (p{sub e} = p{sub t} {minus} p{sub p}, where p{sub t} is the total overburden pressure and p{sub p} is the fluid or pore pressure). This work is based on extensive data collected in Russia. For example, large petroliferous areas in Western Siberia became marshlands as a result of fluid withdrawal. One should remember that sophisticated methods, such as FSMT (direct measurement of rock compaction by wireline tools in situ) and GPS (measurement of surface subsidence by satellite microwave Doppler techniques), are not yet available in many areas of the world.

  6. Novel methods for predicting gas-particle partitioning during the formation of secondary organic aerosol

    NASA Astrophysics Data System (ADS)

    Wania, F.; Lei, Y. D.; Wang, C.; Abbatt, J. P. D.; Goss, K.-U.

    2014-12-01

    Several methods have been presented in the literature to predict an organic chemical's equilibrium partitioning between the water insoluble organic matter (WIOM) component of aerosol and the gas phase, Ki,WIOM, as a function of temperature. They include (i) polyparameter linear free energy relationships calibrated with empirical aerosol sorption data, as well as (ii) the solvation models implemented in SPARC and (iii) the quantum-chemical software COSMOtherm, which predict solvation equilibria from molecular structure alone. We demonstrate that these methods can be used to predict Ki,WIOM for large numbers of individual molecules implicated in secondary organic aerosol (SOA) formation, including those with multiple functional groups. Although very different in their theoretical foundations, these methods give remarkably consistent results for the products of the reaction of normal alkanes with OH, i.e. their partition coefficients Ki,WIOM generally agree within one order of magnitude over a range of more than ten orders of magnitude. This level of agreement is much better than that achieved by different vapour pressure estimation methods that are more commonly used in the SOA community. Also, in contrast to the agreement between vapour pressure estimates, the agreement between the Ki,WIOM estimates does not deteriorate with increasing number of functional groups. Furthermore, these partitioning coefficients Ki,WIOM predicted SOA mass yields in agreement with those measured in chamber experiments of the oxidation of normal alkanes. If a Ki,WIOM prediction method was based on one or more surrogate molecules representing the solvation properties of the mixed OM phase of SOA, the choice of those molecule(s) was found to have a relatively minor effect on the predicted Ki,WIOM, as long as the molecule(s) are not very polar. This suggests that a single surrogate molecule, such as 1-octanol or a hypothetical SOA structure proposed by Kalberer et al. (2004), may often be

  7. A thermodynamic prediction for microporosity formation in aluminum-rich Al-Cu alloys

    NASA Technical Reports Server (NTRS)

    Poirier, D. R.; Yeum, K.; Maples, A. L.

    1987-01-01

    A computer model is used to predict the formation and degree of microporosity in a directionally solidified Al-4.5 wt pct Cu alloy, considering the interplay between solidification shrinkage and gas porosity. Macrosegregation theory is used to determine the local pressure within the interdendritic liquid. Results show interdendritic porosity for initial hydrogen contents in the 0.03-1 ppm range, and none below contents of 0.03. An increase in either the thermal gradient or the solidification rate is show to decrease the amount of interdendritic porosity.

  8. Prediction of carboxyhemoglobin formation due to transient exposure to carbon monoxide

    SciTech Connect

    Benignus, V.A.; Hazucha, M.J.; Smith, M.V.; Bromberg, P.A. Univ. of North Carolina, Chapel Hill, NC )

    1994-04-01

    Fifteen men were exposed to 6,683 ppm C[sup 18]O for 3.09-6.65 min. Arterial and antecubital vein blood samples were drawn at 1-min intervals beginning at the start of C[sup 18]O inhalation and ending 10 min later. Simultaneously, alveolar ventilation was calculated form the measured values of minute ventilation and dead space. All other parameters of the Coburn-Forster-Kane equation (CFKE), except the Haldane affinity ratio, were measured separately in each subject. Means of CFKE predictions of increases in venous HbCO ([Delta]HbCO) in sample collected [approximately]2 min after cessation of exposure were accurate, but the range in errors of prediction for individual subjects was [+-]3.8% HbCO, depending on the time after exposure cessation. Increases in venous and arterial HbCO were inaccurately predicted during and immediately after HbCO formation, however. Venous blood was over-estimated during CO uptake because of a delayed appearance of HbCO. Individual subjects differed markedly in the degree of delay of HbCO appearance in venous blood. Arterial [Delta]HbCO was consistently underestimated either by the CFKE or by predictions based on venous blood samples. Thus, exposure of such organs as brain or heart to HbCO may be substantially higher than expected during transient high-level CO exposure. 19 refs., 3 figs., 2 tabs.

  9. Formation rates, stability and reactivity of sulfuric acid - amine clusters predicted by computational chemistry

    NASA Astrophysics Data System (ADS)

    Kurtén, Theo; Ortega, Ismael; Kupiainen, Oona; Olenius, Tinja; Loukonen, Ville; Reiman, Heidi; McGrath, Matthew; Vehkamäki, Hanna

    2013-04-01

    Despite the importance of atmospheric particle formation for both climate and air quality, both experiments and non-empirical models using e.g. sulfuric acid, ammonia and water as condensing vapors have so far been unable to reproduce atmospheric observations using realistic trace gas concentrations. Recent experimental and theoretical evidence has shown that this mystery is likely resolved by amines. Combining first-principles evaporation rates for sulfuric acid - dimethylamine clusters with cluster kinetic modeling, we show that even sub-ppt concentrations of amines, together with atmospherically realistic concentrations of sulfuric acid, result in formation rates close to those observed in the atmosphere. Our simulated cluster formation rates are also close to, though somewhat larger than, those measured at the CLOUD experiment in CERN for both sulfuric acid - ammonia and sulfuric acid - dimethylamine systems. A sensitivity analysis indicates that the remaining discrepancy for the sulfuric acid - amine particle formation rates is likely caused by steric hindrances to cluster formation (due to alkyl groups of the amine molecules) rather than by significant errors in the evaporation rates. First-principles molecular dynamic and reaction kinetic modeling shed further light on the microscopic physics and chemistry of sulfuric acid - amine clusters. For example, while the number and type of hydrogen bonds in the clusters typically reach their equilibrium values on a picosecond timescale, and the overall bonding patterns predicted by traditional "static" quantum chemical calculations seem to be stable, the individual atoms participating in the hydrogen bonds continuously change at atmospherically realistic temperatures. From a chemical reactivity perspective, we have also discovered a surprising phenomenon: clustering with sulfuric acid molecules slightly increases the activation energy required for the abstraction of alkyl hydrogens from amine molecules. This implies

  10. A bridge-functional-based classical mapping method for predicting the correlation functions of uniform electron gases at finite temperature

    SciTech Connect

    Liu, Yu; Wu, Jianzhong

    2014-02-28

    Efficient and accurate prediction of the correlation functions of uniform electron gases is of great importance for both practical and theoretical applications. This paper presents a bridge-functional-based classical mapping method for calculating the correlation functions of uniform spin-unpolarized electron gases at finite temperature. The bridge functional is formulated by following Rosenfeld's universality ansatz in combination with the modified fundamental measure theory. The theoretical predictions are in good agreement with recent quantum Monte Carlo results but with negligible computational cost, and the accuracy is better than a previous attempt based on the hypernetted-chain approximation. We find that the classical mapping method is most accurate if the effective mass of electrons increases as the density falls.

  11. Role of Excessive Autophagy Induced by Mechanical Overload in Vein Graft Neointima Formation: Prediction and Prevention

    NASA Astrophysics Data System (ADS)

    Chang, Ya-Ju; Huang, Hui-Chun; Hsueh, Yuan-Yu; Wang, Shao-Wei; Su, Fong-Chin; Chang, Chih-Han; Tang, Ming-Jer; Li, Yi-Shuan; Wang, Shyh-Hau; Shung, Kirk K.; Chien, Shu; Wu, Chia-Ching

    2016-02-01

    Little is known regarding the interplays between the mechanical and molecular bases for vein graft restenosis. We elucidated the stenosis initiation using a high-frequency ultrasonic (HFU) echogenicity platform and estimated the endothelium yield stress from von-Mises stress computation to predict the damage locations in living rats over time. The venous-arterial transition induced the molecular cascades for autophagy and apoptosis in venous endothelial cells (ECs) to cause neointimal hyperplasia, which correlated with the high echogenicity in HFU images and the large mechanical stress that exceeded the yield strength. The ex vivo perfusion of arterial laminar shear stress to isolated veins further confirmed the correlation. EC damage can be rescued by inhibiting autophagy formation using 3-methyladenine (3-MA). Pretreatment of veins with 3-MA prior to grafting reduced the pathological increases of echogenicity and neointima formation in rats. Therefore, this platform provides non-invasive temporal spatial measurement and prediction of restenosis after venous-arterial transition as well as monitoring the progression of the treatments.

  12. A novel unscented predictive filter for relative position and attitude estimation of satellite formation

    NASA Astrophysics Data System (ADS)

    Cao, Lu; Chen, Xiaoqian; Misra, Arun K.

    2015-07-01

    This paper presents a novel sigma-point unscented predictive filter (UPF) for relative position and attitude estimation of satellite formation taking into account the influence of J2. A coupled relative translational dynamics model is formulated to represent orbital motion of arbitrary feature points on the deputy spacecraft, and the relative attitude motion is formulated by considering a rotational dynamics for a satellite without gyros. Based on the proposed coupled dynamic model, the UPF is developed based on unscented transformation technique, extending the capability of a traditional predictive filter (PF). The algorithm flow of the UPF is described first. Then it is demonstrated that the estimation accuracy of the model error and system state for UPF is higher than that of the traditional PF. In addition, the unscented Kalman filter (UKF) is also employed in order to compare the performance of the proposed UPF with that of the UKF. Several different scenarios are simulated to validate the effectiveness of the coupled dynamics model and the performance of the proposed UPF. Through comparisons, the proposed UPF is shown to yield highly accurate estimation of relative position and attitude during satellite formation flying.

  13. Role of Excessive Autophagy Induced by Mechanical Overload in Vein Graft Neointima Formation: Prediction and Prevention

    PubMed Central

    Chang, Ya-Ju; Huang, Hui-Chun; Hsueh, Yuan-Yu; Wang, Shao-Wei; Su, Fong-Chin; Chang, Chih-Han; Tang, Ming-Jer; Li, Yi-Shuan; Wang, Shyh-Hau; Shung, Kirk K.; Chien, Shu; Wu, Chia-Ching

    2016-01-01

    Little is known regarding the interplays between the mechanical and molecular bases for vein graft restenosis. We elucidated the stenosis initiation using a high-frequency ultrasonic (HFU) echogenicity platform and estimated the endothelium yield stress from von-Mises stress computation to predict the damage locations in living rats over time. The venous-arterial transition induced the molecular cascades for autophagy and apoptosis in venous endothelial cells (ECs) to cause neointimal hyperplasia, which correlated with the high echogenicity in HFU images and the large mechanical stress that exceeded the yield strength. The ex vivo perfusion of arterial laminar shear stress to isolated veins further confirmed the correlation. EC damage can be rescued by inhibiting autophagy formation using 3-methyladenine (3-MA). Pretreatment of veins with 3-MA prior to grafting reduced the pathological increases of echogenicity and neointima formation in rats. Therefore, this platform provides non-invasive temporal spatial measurement and prediction of restenosis after venous-arterial transition as well as monitoring the progression of the treatments. PMID:26915560

  14. A global model of thunderstorm electricity and the prediction of whistler duct formation

    SciTech Connect

    Stansbery, E.K.

    1989-01-01

    A two-dimensional numerical model is created to calculate the electric field and current that flow from a thunderstorm source into the global electrical circuit. The model includes a hemisphere in which the thunderstorm is located, an equalization layer, and a passive magnetic conjugate hemisphere. To maintain the fair weather electric field, the output current from the thunderstorm is allowed to spread out in the ionosphere or flow along the magnetic field lines into the conjugate hemisphere. The vertical current is constant up to approximately 65 km, decays and is redirected horizontally in the ionosphere. Approximately half of the current that reaches the ionosphere flows along magnetic field lines into the conjugate hemisphere while the rest is spread out in the ionosphere and redirected to the fair weather portion of the storm hemisphere. Our results show that it is important to include a realistic model of the equalization layer to evaluate the role of thunderstorm charging of the global circuit. The mapping of thunderstorm electric fields at middle and subauroral latitudes into the magnetic equatorial plane is studied. The geomagnetic field lines are assumed to be dipolar above approximately 150 km. The horizontal electric field computed in the ionosphere by our model is of sufficient size and shape for the formation of electron density irregularities in the magnetosphere. The mechanism involves a localized convection of ionization tubes by ExB drift. It is shown that the horizontal range of the electric field disturbance in the ionosphere must be within approximately 160 km to produce density irregularities necessary for the formation of whistler ducts. Although the electric field strength at ionospheric heights depends sensitively on the conductivity profile, the results presented show that whistler duct formation is possible by thunderstorm generated electric fields.*

  15. Modeling and predicting the biofilm formation of Salmonella Virchow with respect to temperature and pH.

    PubMed

    Ariafar, M Nima; Buzrul, Sencer; Akçelik, Nefise

    2016-03-01

    Biofilm formation of Salmonella Virchow was monitored with respect to time at three different temperature (20, 25 and 27.5 °C) and pH (5.2, 5.9 and 6.6) values. As the temperature increased at a constant pH level, biofilm formation decreased while as the pH level increased at a constant temperature, biofilm formation increased. Modified Gompertz equation with high adjusted determination coefficient (Radj(2)) and low mean square error (MSE) values produced reasonable fits for the biofilm formation under all conditions. Parameters of the modified Gompertz equation could be described in terms of temperature and pH by use of a second order polynomial function. In general, as temperature increased maximum biofilm quantity, maximum biofilm formation rate and time of acceleration of biofilm formation decreased; whereas, as pH increased; maximum biofilm quantity, maximum biofilm formation rate and time of acceleration of biofilm formation increased. Two temperature (23 and 26 °C) and pH (5.3 and 6.3) values were used up to 24 h to predict the biofilm formation of S. Virchow. Although the predictions did not perfectly match with the data, reasonable estimates were obtained. In principle, modeling and predicting the biofilm formation of different microorganisms on different surfaces under various conditions could be possible. PMID:26960360

  16. Modeling and predicting the biofilm formation of Salmonella Virchow with respect to temperature and pH.

    PubMed

    Ariafar, M Nima; Buzrul, Sencer; Akçelik, Nefise

    2016-03-01

    Biofilm formation of Salmonella Virchow was monitored with respect to time at three different temperature (20, 25 and 27.5 °C) and pH (5.2, 5.9 and 6.6) values. As the temperature increased at a constant pH level, biofilm formation decreased while as the pH level increased at a constant temperature, biofilm formation increased. Modified Gompertz equation with high adjusted determination coefficient (Radj(2)) and low mean square error (MSE) values produced reasonable fits for the biofilm formation under all conditions. Parameters of the modified Gompertz equation could be described in terms of temperature and pH by use of a second order polynomial function. In general, as temperature increased maximum biofilm quantity, maximum biofilm formation rate and time of acceleration of biofilm formation decreased; whereas, as pH increased; maximum biofilm quantity, maximum biofilm formation rate and time of acceleration of biofilm formation increased. Two temperature (23 and 26 °C) and pH (5.3 and 6.3) values were used up to 24 h to predict the biofilm formation of S. Virchow. Although the predictions did not perfectly match with the data, reasonable estimates were obtained. In principle, modeling and predicting the biofilm formation of different microorganisms on different surfaces under various conditions could be possible.

  17. The precision of mapping between number words and the approximate number system predicts children's formal math abilities.

    PubMed

    Libertus, Melissa E; Odic, Darko; Feigenson, Lisa; Halberda, Justin

    2016-10-01

    Children can represent number in at least two ways: by using their non-verbal, intuitive approximate number system (ANS) and by using words and symbols to count and represent numbers exactly. Furthermore, by the time they are 5years old, children can map between the ANS and number words, as evidenced by their ability to verbally estimate numbers of items without counting. How does the quality of the mapping between approximate and exact numbers relate to children's math abilities? The role of the ANS-number word mapping in math competence remains controversial for at least two reasons. First, previous work has not examined the relation between verbal estimation and distinct subtypes of math abilities. Second, previous work has not addressed how distinct components of verbal estimation-mapping accuracy and variability-might each relate to math performance. Here, we addressed these gaps by measuring individual differences in ANS precision, verbal number estimation, and formal and informal math abilities in 5- to 7-year-old children. We found that verbal estimation variability, but not estimation accuracy, predicted formal math abilities, even when controlling for age, expressive vocabulary, and ANS precision, and that it mediated the link between ANS precision and overall math ability. These findings suggest that variability in the ANS-number word mapping may be especially important for formal math abilities.

  18. The precision of mapping between number words and the approximate number system predicts children's formal math abilities.

    PubMed

    Libertus, Melissa E; Odic, Darko; Feigenson, Lisa; Halberda, Justin

    2016-10-01

    Children can represent number in at least two ways: by using their non-verbal, intuitive approximate number system (ANS) and by using words and symbols to count and represent numbers exactly. Furthermore, by the time they are 5years old, children can map between the ANS and number words, as evidenced by their ability to verbally estimate numbers of items without counting. How does the quality of the mapping between approximate and exact numbers relate to children's math abilities? The role of the ANS-number word mapping in math competence remains controversial for at least two reasons. First, previous work has not examined the relation between verbal estimation and distinct subtypes of math abilities. Second, previous work has not addressed how distinct components of verbal estimation-mapping accuracy and variability-might each relate to math performance. Here, we addressed these gaps by measuring individual differences in ANS precision, verbal number estimation, and formal and informal math abilities in 5- to 7-year-old children. We found that verbal estimation variability, but not estimation accuracy, predicted formal math abilities, even when controlling for age, expressive vocabulary, and ANS precision, and that it mediated the link between ANS precision and overall math ability. These findings suggest that variability in the ANS-number word mapping may be especially important for formal math abilities. PMID:27348475

  19. Predicting permeability from the characteristic relaxation time and intrinsic formation factor of complex conductivity spectra

    NASA Astrophysics Data System (ADS)

    Revil, A.; Binley, A.; Mejus, L.; Kessouri, P.

    2015-08-01

    Low-frequency quadrature conductivity spectra of siliclastic materials exhibit typically a characteristic relaxation time, which either corresponds to the peak frequency of the phase or the quadrature conductivity or a typical corner frequency, at which the quadrature conductivity starts to decrease rapidly toward lower frequencies. This characteristic relaxation time can be combined with the (intrinsic) formation factor and a diffusion coefficient to predict the permeability to flow of porous materials at saturation. The intrinsic formation factor can either be determined at several salinities using an electrical conductivity model or at a single salinity using a relationship between the surface and quadrature conductivities. The diffusion coefficient entering into the relationship between the permeability, the characteristic relaxation time, and the formation factor takes only two distinct values for isothermal conditions. For pure silica, the diffusion coefficient of cations, like sodium or potassium, in the Stern layer is equal to the diffusion coefficient of these ions in the bulk pore water, indicating weak sorption of these couterions. For clayey materials and clean sands and sandstones whose surface have been exposed to alumina (possibly iron), the diffusion coefficient of the cations in the Stern layer appears to be 350 times smaller than the diffusion coefficient of the same cations in the pore water. These values are consistent with the values of the ionic mobilities used to determine the amplitude of the low and high-frequency quadrature conductivities and surface conductivity. The database used to test the model comprises a total of 202 samples. Our analysis reveals that permeability prediction with the proposed model is usually within an order of magnitude from the measured value above 0.1 mD. We also discuss the relationship between the different time constants that have been considered in previous works as characteristic relaxation time, including

  20. Molecular dynamics of single-particle impacts predicts phase diagrams for large scale pattern formation.

    PubMed

    Norris, Scott A; Samela, Juha; Bukonte, Laura; Backman, Marie; Djurabekova, Flyura; Nordlund, Kai; Madi, Charbel S; Brenner, Michael P; Aziz, Michael J

    2011-01-01

    Energetic particle irradiation can cause surface ultra-smoothening, self-organized nanoscale pattern formation or degradation of the structural integrity of nuclear reactor components. A fundamental understanding of the mechanisms governing the selection among these outcomes has been elusive. Here we predict the mechanism governing the transition from pattern formation to flatness using only parameter-free molecular dynamics simulations of single-ion impacts as input into a multiscale analysis, obtaining good agreement with experiment. Our results overturn the paradigm attributing these phenomena to the removal of target atoms via sputter erosion: the mechanism dominating both stability and instability is the impact-induced redistribution of target atoms that are not sputtered away, with erosive effects being essentially irrelevant. We discuss the potential implications for the formation of a mysterious nanoscale topography, leading to surface degradation, of tungsten plasma-facing fusion reactor walls. Consideration of impact-induced redistribution processes may lead to a new design criterion for stability under irradiation.

  1. A distributed model predictive control (MPC) fault reconfiguration strategy for formation flying satellites

    NASA Astrophysics Data System (ADS)

    Esfahani, N. R.; Khorasani, K.

    2016-05-01

    In this paper, an active distributed (also referred to as semi-decentralised) fault recovery control scheme is proposed that employs inaccurate and unreliable fault information into a model-predictive-control-based design. The objective is to compensate for the identified actuator faults that are subject to uncertainties and detection time delays, in the attitude control subsystems of formation flying satellites. The proposed distributed fault recovery scheme is developed through a two-level hierarchical framework. In the first level, or the agent level, the fault is recovered locally to maintain as much as possible the design specifications, feasibility, and tracking performance of all the agents. In the second level, or the formation level, the recovery is carried out by enhancing the entire team performance. The fault recovery performance of our proposed distributed (semi-decentralised) scheme is compared with two other alternative schemes, namely the centralised and the decentralised fault recovery schemes. It is shown that the distributed (semi-decentralised) fault recovery scheme satisfies the recovery design specifications and also imposes lower fault compensation control effort cost and communication bandwidth requirements as compared to the centralised scheme. Our proposed distributed (semi-decentralised) scheme also outperforms the achievable performance capabilities of the decentralised scheme. Simulation results corresponding to a network of four precision formation flight satellites are also provided to demonstrate and illustrate the advantages of our proposed distributed (semi-decentralised) fault recovery strategy.

  2. Predicting Galaxy Star Formation Rates via the Co-evolution of Galaxies and Halos

    SciTech Connect

    Watson, Douglas F.; Hearin, Andrew P.; Berlind, Andreas A.; Becker, Matthew R.; Behroozi, Peter S.; Skibba, Ramin A.; Reyes, Reinabelle; Zentner, Andrew R.

    2014-03-06

    In this paper, we test the age matching hypothesis that the star formation rate (SFR) of a galaxy is determined by its dark matter halo formation history, and as such, that more quiescent galaxies reside in older halos. This simple model has been remarkably successful at predicting color-based galaxy statistics at low redshift as measured in the Sloan Digital Sky Survey (SDSS). To further test this method with observations, we present new SDSS measurements of the galaxy two-point correlation function and galaxy-galaxy lensing as a function of stellar mass and SFR, separated into quenched and star forming galaxy samples. We find that our age matching model is in excellent agreement with these new measurements. We also employ a galaxy group finder and show that our model is able to predict: (1) the relative SFRs of central and satellite galaxies, (2) the SFR-dependence of the radial distribution of satellite galaxy populations within galaxy groups, rich groups, and clusters and their surrounding larger scale environments, and (3) the interesting feature that the satellite quenched fraction as a function of projected radial distance from the central galaxy exhibits an approx r-.15 slope, independent of environment. The accurate prediction for the spatial distribution of satellites is intriguing given the fact that we do not explicitly model satellite-specific processes after infall, and that in our model the virial radius does not mark a special transition region in the evolution of a satellite, contrary to most galaxy evolution models. The success of the model suggests that present-day galaxy SFR is strongly correlated with halo mass assembly history.

  3. The GIS layers of the "International Hydrogeological Map of Europe 1:1,500,000" in a vector format

    NASA Astrophysics Data System (ADS)

    Duscher, Klaus; Günther, Andreas; Richts, Andrea; Clos, Patrick; Philipp, Uta; Struckmeier, Wilhelm

    2015-12-01

    The map series of the International Hydrogeological Map of Europe at a scale of 1:1,500,000 (IHME1500) has been completed by the publication of the last two map sheets in August 2013. Altogether, the 25 sheets of the IHME1500 provide the first coherent overview of groundwater resources in Europe. The map displays productivity and lithology of potential aquifer systems. Some of the additional map contents relating to groundwater are presented only regionally. The most relevant features of IHME1500 are compiled in two seamless geographic information system (GIS) layers in shapefile format: (1) showing groundwater resources characterised by a basic aquifer typology, including a lithological description and areas of seawater intrusion, and (2) reproducing major tectonic fractures. The superficial lithology information was harmonised by implementing a lithological taxonomy and a multi-step aggregation. An enhancement of the GIS layers is envisaged through the release of updates, which will be distinguished by consecutive version numbers. The continent-wide harmonised presentation of contents constitutes the main feature of the IHME1500 GIS layers. This qualifies the spatial dataset as a basic tool for hydrogeological assessments aiming primarily at transboundary issues. Map scale and the manufacture date of the analogue base impose restrictions on the application of the IHME1500 vector data. A set of examples describes the initial use of the GIS layers in research projects and illustrates potential fields of application. The IHME1500 lithology layer establishes a spatial dataset suitable for the continent-wide evaluation of geological surface processes like the susceptibility to landslides.

  4. Rice crop mapping and change prediction using multi-temporal satellite images in the Mekong Delta, Vietnam

    NASA Astrophysics Data System (ADS)

    Chen, C. R.; Chen, C. F.; Nguyen, S. T.

    2014-12-01

    The rice cropping systems in the Vietnamese Mekong Delta (VMD) has been undergoing major changes to cope with developing agro-economics, increasing population and changing climate. Information on rice cropping practices and changes in cropping systems is critical for policymakers to devise successful strategies to ensure food security and rice grain exports for the country. The primary objective of this research is to map rice cropping systems and predict future dynamics of rice cropping systems using the MODIS time-series data of 2002, 2006, and 2010. First, a phenology-based classification approach was applied for the classification and assessment of rice cropping systems in study region. Second, the Cellular Automata-Markov (CA-Markov) models was used to simulate the rice-cropping system map of VMD for 2010. The comparisons between the classification maps and the ground reference data indicated satisfactory results with overall accuracies and Kappa coefficients, respectively, of 81.4% and 0.75 for 2002, 80.6% and 0.74 for 2006 and 85.5% and 0.81 for 2010. The simulated map of rice cropping system for 2010 was extrapolated by CA-Markov model based on the trend of rice cropping systems during 2002~2006. The comparison between predicted scenario and classification map for 2010 presents a reasonably closer agreement. In conclusion, the CA-Markov model performs a powerful tool for the dynamic modeling of changes in rice cropping systems, and the results obtained demonstrate that the approach produces satisfactory results in terms of accuracy, quantitative forecast and spatial pattern changes. Meanwhile, the projections of the future changes would provide useful inputs to the agricultural policy for effective management of the rice cropping practices in VMD.

  5. Pulling the Trigger on Star Formation: Expanded CO (J = 2 → 1) Maps of M17 and Vicinity

    NASA Astrophysics Data System (ADS)

    Sanchez, Natalie; Bieging, J. H.; Povich, M. S.; Rudolph, A. L.

    2013-01-01

    M17, also known as the Omega Nebula, is a well-known region of star formation characterized by a prominent HII region, photodissociation region and extensive giant molecular cloud (GMC). We have mapped the molecular cloud region surrounding M17 in 12CO and 13CO (J = 2 → 1) emission lines with the Heinrich Hertz Telescope. The three dimensional data cubes reveal the full extended shell structure of the molecular gas associated with the HII region, concentrated between v = 15 to 25 km/s. Utilizing a catalog of young stellar objects (YSOs) compiled from both Spitzer GLIMPSE and complementary near infrared data, we can see their distribution within and around the GMC. We find a concentration of YSOs in the northern rim of the molecular cloud; however, star formation is not observed in the newly mapped region farther north. We also observe unassociated structures near M17 at higher velocities, including one shell-like structure that is also characterized by a concentration of YSOs around its rim. We propose that the shell structure may have been produced by an older HII region. The blown out shells may have triggered the star formation in the isolated regions we now observe.

  6. Prediction of bathymetry from satellite altimeter based gravity in the Arabian Sea: Mapping of two unnamed deep seamounts

    NASA Astrophysics Data System (ADS)

    Jena, B.; Kurian, P. J.; Swain, D.; Tyagi, A.; Ravindra, R.

    2012-06-01

    This work attempts to predict bathymetry from satellite altimeter based gravity in the Arabian Sea. A collocated match-up database (n = 17,016) was created on Multibeam Echosounder (MBES) bathymetry and satellite gravity values (˜1 min spatial resolution) derived from remote sensing satellites. A Radial Basis Function (RBF) based Artificial Neural Network (ANN) model was developed to predict bathymetry from satellite gravity values. The ANN model was trained with variable undersea features such as seamount, knoll, abyssal plain, hill, etc. to familiarize the network with all possible geomorphic features as inputs through learning and the corresponding target outputs. The performance of the predictive model was evaluated by comparing bathymetric values with MBES datasets that were not used during the training and verification steps of the ANN model formulation. The model was then compared with MBES surveyed seamount observations (those were not used during ANN analysis) and global model bathymetry products. Results demonstrate better performance of ANN model compared to global model products for mapping of two unnamed seamounts in the Arabian Sea. These two unnamed seamounts have been predicted, mapped and their morphology is reported for the first time through this work.

  7. Map showing contours on the top of the Pennsylvanian and Permian Minnelusa Formation and equivalents, Powder River basin, Wyoming and Montana

    USGS Publications Warehouse

    Crysdale, B.L.

    1990-01-01

    This map is one in a series of U.S. Geological Survey Miscellaneous Field Studies (MF) maps showing computer-generated structure contours, isopachs, and cross sections of selected formations in the Powder River basin, Wyoming and Montana. The map and cross sections were constructed from information stored in a U.S. Geological Survey Evolution of Sedimentary Basins data base. This data base contains picks of geologic formation and (or) unit tops and bases determined from electric resistivity and gamma-ray logs of 8,592 wells penetrating Tertiary and older rocks in the Powder River basin. Well completion cards (scout tickets) were reviewed and compared with copies of all logs, and formation or unit contacts determined by N. M. Denson, D.L. Macke, R. R. Schumann and others. This isopach map is based on information from 1,480 of these wells that penetrate the Minnelusa Formation and equivalents.

  8. Isopach map of the interval from surface elevation to the top of the Pennsylvanian and Permian Minnelusa Formation and equivalents, Powder River basin, Wyoming and Montana

    USGS Publications Warehouse

    Crysdale, B.L.

    1990-01-01

    This map is one in a series of U.S. Geological Survey Miscellaneous Field Studies (MF) maps showing computer-generated structure contours, isopachs, and cross sections of selected formations in the Powder River basin, Wyoming and Montana. The map and cross sections were constructed from information stored in a U.S. Geological Survey Evolution of Sedimentary Basins data base. This data base contains picks of geologic formation and (or) unit tops and bases determined from electric resistivity and gamma-ray logs of 8,592 wells penetrating Tertiary and older rocks in the Powder River basin. Well completion cards (scout tickets) were reviewed and compared with copies of all logs, and formation or unit contacts determined by N. M. Denson, D.L. Macke, R. R. Schumann and others. This isopach map is based on information from 1,480 of these wells that penetrate the Minnelusa Formation and equivalents.

  9. Structural Mapping of the Tunnunik Impact Structure, NWT, Canada: Insights in to Central Uplift Formation

    NASA Astrophysics Data System (ADS)

    Osinski, G. R.; Francis, R.; Hansen, J.; Marion, C. L.; Pickersgill, A. E.; Tornabene, L. L.

    2013-08-01

    We report on structural mapping of the newly discovered Tunnunik impact structure, a 28 km diameter structure in the Canadian Arctic. The central uplift is exposed in a 2 km long canyon and features thrust-faulted blocks and outwards dipping strata.

  10. Predictions for the formation of atomic chains in mechanically controllable break-junction experiments

    NASA Astrophysics Data System (ADS)

    Fernández-Seivane, Lucas; García-Suárez, Víctor M.; Ferrer, Jaime

    2007-02-01

    We analyze the stability and magnetic properties of infinite zigzag atomic chains of a large number of late third-, fourth-, and fifth-row transition-metal atoms, as well as of the group-IV elements Si, Ge, Sn, and Pb. We find that zigzag chains of third- and fourth-row elements are not stable, while those made of Si, Ge, Sn, Pb, W, Os, Ir, Pt, and Au are. These results correlate well with known data in mechanically controllable break-junction experiments (MCBJEs). We therefore conjecture that the stability of an infinite chain is at least a necessary condition for the formation of a finite-sized one in MCBJEs. We therefore predict that Sn and Os, and possibly W and Pb chains, may be found in those experiments. We also find that the bonds in Hg chains are extremely soft. We finally show that the magnetic moments and anisotropies of Ir and Pt chains show a nontrivial behavior.

  11. Prediction of carboxyhemoglobin formation due to transient exposure to carbon monoxide

    SciTech Connect

    Benignus, V.A.; Hazucha, M.J.; Smith, M.V.; Bromberg, P.A.

    1994-04-01

    Fifteen men were exposed to 6,683 ppm C(18)O for 3.09-6.65 min. Arterial and antecubital vein blood samples were drawn at 1-min intervals beginning at the start of C(18)O inhalation and ending 10 min later. Simultaneously, alveolar ventilation was calculated from the measured values of minute ventilation and dead space. All other parameters of the Coburn-Forster-Kane equation (CFKE), except the Haldane affinity ratio, were measured separately in each subject. Increases in venous and arterial HbCO were inaccurately predicted during and immediately after HbCO formation. Exposure of such organs as brain or heart to carboxyhemoglobin (HbCO) may be substantially higher than expected during transient high-level CO exposure.

  12. A-DROP: A predictive model for the formation of oil particle aggregates (OPAs)

    USGS Publications Warehouse

    Zhao, Lin; Boufadel, Michel C.; Geng, Xiaolong; Lee, Kenneth; King, Thomas; Robinson, Brian; Fitzpatrick, Faith A.

    2016-01-01

    Oil–particle interactions play a major role in removal of free oil from the water column. We present a new conceptual–numerical model, A-DROP, to predict oil amount trapped in oil–particle aggregates. A new conceptual formulation of oil–particle coagulation efficiency is introduced to account for the effects of oil stabilization by particles, particle hydrophobicity, and oil–particle size ratio on OPA formation. A-DROP was able to closely reproduce the oil trapping efficiency reported in experimental studies. The model was then used to simulate the OPA formation in a typical nearshore environment. Modeling results indicate that the increase of particle concentration in the swash zone would speed up the oil–particle interaction process; but the oil amount trapped in OPAs did not correspond to the increase of particle concentration. The developed A-DROP model could become an important tool in understanding the natural removal of oil and developing oil spill countermeasures by means of oil–particle aggregation.

  13. A-DROP: A predictive model for the formation of oil particle aggregates (OPAs).

    PubMed

    Zhao, Lin; Boufadel, Michel C; Geng, Xiaolong; Lee, Kenneth; King, Thomas; Robinson, Brian; Fitzpatrick, Faith

    2016-05-15

    Oil-particle interactions play a major role in removal of free oil from the water column. We present a new conceptual-numerical model, A-DROP, to predict oil amount trapped in oil-particle aggregates. A new conceptual formulation of oil-particle coagulation efficiency is introduced to account for the effects of oil stabilization by particles, particle hydrophobicity, and oil-particle size ratio on OPA formation. A-DROP was able to closely reproduce the oil trapping efficiency reported in experimental studies. The model was then used to simulate the OPA formation in a typical nearshore environment. Modeling results indicate that the increase of particle concentration in the swash zone would speed up the oil-particle interaction process; but the oil amount trapped in OPAs did not correspond to the increase of particle concentration. The developed A-DROP model could become an important tool in understanding the natural removal of oil and developing oil spill countermeasures by means of oil-particle aggregation.

  14. An Empirical and Simple Model For Predicting Marine Snow Formation During Diatom Blooms

    NASA Astrophysics Data System (ADS)

    Ruiz, J.; Prieto, L.; Echevarría, F.; García, C. M.; Gálvez, J. A.; Bartual, A.; Corzo, A.; Macías, D.

    Diatom aggregates are a significant component of the downward particle flux recorded by sediment traps during phytoplankton blooms. However, although these large parti- cles are an important vector for the transfer of carbon to the deep ocean, there is a lack of empirical approaches to formulate their generation at the ocean surface. There is also the need for simplicity in these formulations so that they become a tool useful to researchers needing to simulate the formation of theses particles. In this presentation we propose one formulation based on experimental data obtained in a mesocosm (500 l) experiment where two diatom blooms were recorded. This formulation predicts very well (r2=95%) the time derivative of aggregate concentration with only one parameter and two size classes (single phytoplankton cells and aggregates). The numerical value of the parameter is robust to the diatom species forming the aggregates. Therefore, it offers a simple alternative to prognose the formation of marine snow and its associated fluxes at episodes of diatom blooms.

  15. Mercury's core fraction and ancient crustal composition: Predictions from planetary formation under extremely reducing conditions

    NASA Astrophysics Data System (ADS)

    Brown, S. M.; Elkins-Tanton, L.

    2007-12-01

    Several hypotheses have been suggested to explain the paradox of Mercury's large core, which is on the order of sixty percent of the mass of the planet and recently demonstrated to be at least partially molten. Here we suggest that extremely reducing conditions in the earliest stages of planetary accretion nearest to the Sun may have produced the unusual metallic iron fraction by reducing iron otherwise bound into silicates. We demonstrate the formation conditions necessary for various meteoritic bulk compositions to produce the core/mantle ratio of Mercury. During this hypothetical core formation, we assume the remaining silicate fraction of Mercury (now largely lacking iron) has been heated to produce a magma ocean. The resulting cumulate mantle composition is calculated in a Matlab simulation of magma ocean solidification using a CMAS system adapted for Mercury. Plagioclase flotation, frequently cited as the necessary signature of a magma ocean, is highly dependent upon initial bulk composition. We demonstrate the initial silicate iron content of the magma ocean necessary to make plagioclase buoyant and thus produce a plagioclase flotation crust as seen on the Moon. In addition, over a range of bulk compositions the solidified mantle cumulates are unstable to gravitational overturn. During overturn hot cumulates rise from depth and may cross their solidi and melt, producing an earliest planetary crust. This crust may still exist on Mercury. With the first flyby results of the MESSENGER mission coming this winter, predictions from these models can be compared with initial ground measurements.

  16. A-DROP: A predictive model for the formation of oil particle aggregates (OPAs).

    PubMed

    Zhao, Lin; Boufadel, Michel C; Geng, Xiaolong; Lee, Kenneth; King, Thomas; Robinson, Brian; Fitzpatrick, Faith

    2016-05-15

    Oil-particle interactions play a major role in removal of free oil from the water column. We present a new conceptual-numerical model, A-DROP, to predict oil amount trapped in oil-particle aggregates. A new conceptual formulation of oil-particle coagulation efficiency is introduced to account for the effects of oil stabilization by particles, particle hydrophobicity, and oil-particle size ratio on OPA formation. A-DROP was able to closely reproduce the oil trapping efficiency reported in experimental studies. The model was then used to simulate the OPA formation in a typical nearshore environment. Modeling results indicate that the increase of particle concentration in the swash zone would speed up the oil-particle interaction process; but the oil amount trapped in OPAs did not correspond to the increase of particle concentration. The developed A-DROP model could become an important tool in understanding the natural removal of oil and developing oil spill countermeasures by means of oil-particle aggregation. PMID:26992749

  17. Protein pheromone expression levels predict and respond to the formation of social dominance networks.

    PubMed

    Nelson, A C; Cunningham, C B; Ruff, J S; Potts, W K

    2015-06-01

    Communication signals are key regulators of social networks and are thought to be under selective pressure to honestly reflect social status, including dominance status. The odours of dominants and nondominants differentially influence behaviour, and identification of the specific pheromones associated with, and predictive of, dominance status is essential for understanding the mechanisms of network formation and maintenance. In mice, major urinary proteins (MUPs) are excreted in extraordinary large quantities and expression level has been hypothesized to provide an honest signal of dominance status. Here, we evaluate whether MUPs are associated with dominance in wild-derived mice by analysing expression levels before, during and after competition for reproductive resources over 3 days. During competition, dominant males have 24% greater urinary MUP expression than nondominants. The MUP darcin, a pheromone that stimulates female attraction, is predictive of dominance status: dominant males have higher darcin expression before competition. Dominants also have a higher ratio of darcin to other MUPs before and during competition. These differences appear transient, because there are no differences in MUPs or darcin after competition. We also find MUP expression is affected by sire dominance status: socially naive sons of dominant males have lower MUP expression, but this apparent repression is released during competition. A requisite condition for the evolution of communication signals is honesty, and we provide novel insight into pheromones and social networks by showing that MUP and darcin expression is a reliable signal of dominance status, a primary determinant of male fitness in many species.

  18. Formation and prediction of structural traps in northwest Beartooth Mountains near Livingston, Montana

    SciTech Connect

    Robbins, E.A.; Erslev, E.A.

    1986-08-01

    The bounding faults on the northeastern flank of the Beartooth Mountains display a reversal of thrust vergence, with southwest-dipping thrust faults in the southeast, and northeast-dipping thrust faults in the northwest. Previous structural models of the Beartooth uplift do not explain this reversal in vergence because they do not balance by sedimentary bed length or basement block area and are not restorable to conceivable initial geometries. In addition, the models do not account for the thin-skinned deformation exposed along the northwestern corner. Restorable models for the northwest Beartooth uplift predict a blind master thrust, dipping to the southwest with wedges of basement back thrust over the main block. The basement-wedge formation is probably responsible for complex thin-skinned thrusts, duplexes, and ramp structures that fill apparent strain incompatibilities (space problems) for the southeast and northwest corners of the uplift. Estimates of 8 to 14 km (5 to 7 mi) of upper crustal shortening are consistent with published estimates from gravity modeling to the southeast. Geometric balancing techniques that conserve basement area and sediment bed length provide strong constraints on the structural geometry of foreland uplifts in the Rocky Mountain region. In the Beartooth Mountains, the complex interplay between the postulated southwest-dipping master fault, northeast-dipping back thrusts, and thin-skinned deformation allow for multiple structural traps for petroleum accumulation. The surface exposures in the Beartooth Mountain uplift do not suggest the subsurface complexity predicted by the balanced cross sections.

  19. Becoming popular: interpersonal emotion regulation predicts relationship formation in real life social networks

    PubMed Central

    Niven, Karen; Garcia, David; van der Löwe, Ilmo; Holman, David; Mansell, Warren

    2015-01-01

    Building relationships is crucial for satisfaction and success, especially when entering new social contexts. In the present paper, we investigate whether attempting to improve others’ feelings helps people to make connections in new networks. In Study 1, a social network study following new networks of people for a 12-week period indicated that use of interpersonal emotion regulation (IER) strategies predicted growth in popularity, as indicated by other network members’ reports of spending time with the person, in work and non-work interactions. In Study 2, linguistic analysis of the tweets from over 8000 Twitter users from formation of their accounts revealed that use of IER predicted greater popularity in terms of the number of followers gained. However, not all types of IER had positive effects. Behavioral IER strategies (which use behavior to reassure or comfort in order to regulate affect) were associated with greater popularity, while cognitive strategies (which change a person’s thoughts about his or her situation or feelings in order to regulate affect) were negatively associated with popularity. Our findings have implications for our understanding of how new relationships are formed, highlighting the important the role played by intentional emotion regulatory processes. PMID:26483718

  20. Modeling Career Counselor Decisions with Artificial Neural Networks: Predictions of Fit across a Comprehensive Occupational Map.

    ERIC Educational Resources Information Center

    Carson, Andrew D.; Bizot, Elizabeth B.; Hendershot, Peggy E.; Barton, Margaret G.; Garvin, Mary K.; Kraemer, Barbara

    1999-01-01

    Career recommendations were made based on aptitude scores of 335 high school freshmen. Artificial neural networks were used to map recommendations to 12 occupational clusters. Overall accuracy of neural networks (.80) approached that of discriminant function analysis (.84). The two methods had different strengths and weaknesses. (SK)

  1. Haplotype mapping and sequence analysis of the mouse Nramp gene predict susceptibility to infection with intracellular parasites

    SciTech Connect

    Malo, D.; Hu, Jinxin; Schurr, E.

    1994-09-01

    The mouse chromosome 1 locus Bcg (Ity, Lsh) controls the capacity of the tissue macrophage to restrict the replication of antigenically unrelated intracellular parasites and therefore determines the natural resistance (BCG-R, dominant) or susceptibility (BCG-S, recessive) of inbred mouse strains to infection with diverse pathogens. We have used a positional cloning strategy based on genetic and physical mapping, YAC cloning, and exon trapping to isolate a candidate gene for Beg (Nramp) that encodes a predicted macrophage-specific transport protein. We have analyzed a total of 27 inbred mouse strains of BCG-R and BCG-S phenotypes for the presence of nucleotide sequence variations within the coding portion of Nramp and have carried out haplotype typing of the corresponding chromosome 1 region in these mice, using 11 additional polymorphic markers mapping in the immediate vicinity of Nramp. cDNA cloning and nucleotide sequencing identified 5 nucleotide sequence variations within Nramp in the inbred strains.

  2. Amplification and over-expression of MAP3K3 gene in human breast cancer promotes formation and survival of breast cancer cells

    PubMed Central

    Fan, Yihui; Ge, Ningling; Wang, Xiaosong; Sun, Wenjing; Mao, Renfang; Bu, Wen; Creighton, Chad J; Zheng, Pingju; Vasudevan, Sanjeev; An, Lei; Yang, Jinshu; Zhao, Yi-Jue; Zhang, Huiyuan; Li, Xiao-Nan; Rao, Pulivarthi H; Leung, Eastwood; Lu, Yong-Jie; Gray, Joe W; Schiff, Rachel; Hilsenbeck, Susan G; Osborne, C Kent; Yang, Jianhua; Zhang, Hong

    2014-01-01

    Gene amplifications in the 17q chromosomal region are observed frequently in breast cancers. An integrative bioinformatics analysis of this region nominated the MAP3K 3 gene as a potential therapeutic target in breast cancer. This gene encodes mitogen-activated protein kinase kinase kinase 3 (MAP3K3/MEKK3), which has not yet been reported to be associated with cancer-causing genetic aberrations. We found that MAP3K3 was amplified in approximately 8–20% of breast cancers. Knockdown of MAP3K3 expression significantly inhibited cell proliferation and colony formation in MAP3K3-amplified breast cancer cell lines MCF-7 and MDA-MB-361 but not in MAP3K3 non-amplified breast cancer cells. Knockdown of MAP3K3 expression in MAP3K3-amplified breast cancer cells sensitized breast cancer cells to apoptotic induction by TNFα and TRAIL, as well as doxorubicin, VP-16 and fluorouracil, three commonly used chemotherapeutic drugs for treating breast cancer. In addition, ectopic expression of MAP3K3, in collaboration with Ras, induced colony formation in both primary mouse embryonic fibroblasts and immortalized human breast epithelial cells (MCF-10A). Combined, these results suggest that MAP3K3 contributes to breast carcinogenesis and may endow resistance of breast cancer cells to cytotoxic chemotherapy. Therefore, MAP3K3 may be a valuable therapeutic target in patients with MAP3K3-amplified breast cancers, and blocking MAP3K3 kinase activity with a small molecule inhibitor may sensitize MAP3K3-amplified breast cancer cells to chemotherapy. PMID:24122835

  3. Potential of EnMAP spaceborne imaging spectroscopy for the prediction of common surface soil properties and expected accuracy

    NASA Astrophysics Data System (ADS)

    Chabrillat, Sabine; Foerster, Saskia; Steinberg, Andreas; Stevens, Antoine; Segl, Karl

    2016-04-01

    There is a renewed awareness of the finite nature of the world's soil resources, growing concern about soil security, and significant uncertainties about the carrying capacity of the planet. As a consequence, soil scientists are being challenged to provide regular assessments of soil conditions from local through to global scales. However, only a few countries have the necessary survey and monitoring programs to meet these new needs and existing global data sets are out-of-date. A particular issue is the clear demand for a new area-wide regional to global coverage with accurate, up-to-date, and spatially referenced soil information as expressed by the modeling scientific community, farmers and land users, and policy and decision makers. Soil spectroscopy from remote sensing observations based on studies from the laboratory scale to the airborne scale has been shown to be a proven method for the quantitative prediction of key soil surface properties in local areas for exposed soils in appropriate surface conditions such as low vegetation cover and low water content. With the upcoming launch of the next generation of hyperspectral satellite sensors in the next 3 to 5 years (EnMAP, HISUI, PRISMA, SHALOM), a great potential for the global mapping and monitoring of soil properties is appearing. Nevertheless, the capabilities to extend the soil properties current spectral modeling from local to regional scales are still to be demonstrated using robust methods. In particular, three central questions are at the forefront of research nowadays: a) methodological developments toward improved algorithms and operational tools for the extraction of soil properties, b) up scaling from the laboratory into space domain, and c) demonstration of the potential of upcoming satellite systems and expected accuracy of soil maps. In this study, airborne imaging spectroscopy data from several test sites are used to simulate EnMAP satellite images at 30 m scale. Then, different soil

  4. The Choice between MapMan and Gene Ontology for Automated Gene Function Prediction in Plant Science

    PubMed Central

    Klie, Sebastian; Nikoloski, Zoran

    2012-01-01

    Since the introduction of the Gene Ontology (GO), the analysis of high-throughput data has become tightly coupled with the use of ontologies to establish associations between knowledge and data in an automated fashion. Ontologies provide a systematic description of knowledge by a controlled vocabulary of defined structure in which ontological concepts are connected by pre-defined relationships. In plant science, MapMan and GO offer two alternatives for ontology-driven analyses. Unlike GO, initially developed to characterize microbial systems, MapMan was specifically designed to cover plant-specific pathways and processes. While the dependencies between concepts in MapMan are modeled as a tree, in GO these are captured in a directed acyclic graph. Therefore, the difference in ontologies may cause discrepancies in data reduction, visualization, and hypothesis generation. Here provide the first systematic comparative analysis of GO and MapMan for the case of the model plant species Arabidopsis thaliana (Arabidopsis) with respect to their structural properties and difference in distributions of information content. In addition, we investigate the effect of the two ontologies on the specificity and sensitivity of automated gene function prediction via the coupling of co-expression networks and the guilt-by-association principle. Automated gene function prediction is particularly needed for the model plant Arabidopsis in which only half of genes have been functionally annotated based on sequence similarity to known genes. The results highlight the need for structured representation of species-specific biological knowledge, and warrants caution in the design principles employed in future ontologies. PMID:22754563

  5. Hepatitis B virus HBx protein activates Ras-GTP complex formation and establishes a Ras, Raf, MAP kinase signaling cascade.

    PubMed Central

    Benn, J; Schneider, R J

    1994-01-01

    Hepatitis B virus produces a small (154-amino acid) transcriptional transactivating protein, HBx, which is required for viral infection and has been implicated in virus-mediated liver oncogenesis. However, the molecular mechanism for HBx activity and its possible influence on cell proliferation have remained obscure. A number of studies suggest that HBx may stimulate transcription by indirectly activating transcription factors, possibly by influencing cell signaling pathways. We now present biochemical evidence that HBx activates Ras and rapidly induces a cytoplasmic signaling cascade linking Ras, Raf, and mitogen-activated protein kinase (MAP kinase), leading to transcriptional transactivation. HBx strongly elevates levels of GTP-bound Ras, activated and phosphorylated Raf, and tyrosine-phosphorylated and activated MAP kinase. Transactivation of transcription factor AP-1 by HBx is blocked by inhibition of Ras or Raf activities but not by inhibition of Ca(2+)- and diacylglycerol-dependent protein kinase C. HBx was also found to stimulate DNA synthesis in serum-starved cells. The hepatitis B virus HBx protein therefore stimulates Ras-GTP complex formation and promotes downstream signaling through Raf and MAP kinases, and may influence cell proliferation. Images PMID:7937954

  6. Mapping Physical Formats to Logical Models to Extract Data and Metadata: The Defuddle Parsing Engine

    SciTech Connect

    Talbott, Tara D.; Schuchardt, Karen L.; Stephan, Eric G.; Myers, James D.

    2006-07-25

    Scientists, fueled by the desire for systems-level understanding of phenomena, increasingly need to share their results across multiple disciplines. Accomplishing this requires data to be annotated, contextualized, and readily searchable and translated into other formats. While these requirements can be addressed by custom programming or obviated by community standardization, neither approach has ‘solved’ the problem. In this paper, we describe a complementary approach – a general capability for articulating the format of arbitrary textual and binary data using a logical data model, expressed in XML-Schema, which can be used to provide annotation and context, extract metadata, and enable translation. This work is based on the draft specification for the Data Format Description Language and our open source “Defuddle” parser. We present an overview of the specification, detail the design of Defuddle, and discuss the benefits and challenges of this general approach to enabling discovery and sharing of diverse data sets.

  7. Evaluation of Lava Tube Formation Mechanisms Using Three-Dimensional Mapping, and Viscosity Modeling: Lava Beds National Monument, California.

    NASA Astrophysics Data System (ADS)

    Dedecker, J.; Gant, M.

    2014-12-01

    This study explores the relationships between lava tube morphology, lava effusion rate estimates, and the mechanism of lava tube formation. Effusion rate estimates for extinct lava tubes were calculated using a combination of three-dimensional mapping of lava tube caves, and viscosity models utilizing whole-rock compositions (Giordano et al., 2008, Earth Planet. Sci. Lett.), and petrographic data (Harris and Allen, 2008, J. Geophys. Res.). The mechanism of lava tube formation was evaluated using measured tube lengths and effusion rate estimates and comparing these data with observations from Hawaiian channel- and tube-fed flows (Pinkerton and Wilson, 1994, J. Volcanol. Geoth. Res.). Three-dimensional map data for lava tube caves were collected using a laser rangefinder to measure the cross-sectional shape and down-tube distance, and a tandem compass/inclinometer to measure the azimuth and inclination between survey stations in the tube. Total tube length consists of the mapped tube length plus the distance between collapse pits and trenches along the trend of the tube. Effusion rates were estimated using the Hagen-Poiseuille equation, measured mean cross-sectional radii and slope of lava tubes, and estimated effective viscosities of rock samples collected from mapped tubes at temperatures between 1080-1160 °C and water contents of 0-1 wt.%. A lava density of 1560 g/cm3was used for 0.40 vesicle fraction basalt. There is a positive correlation between measured tube lengths and cross-sectional radii (Fig. 1). We propose that this relationship reflects the positive correlation between flow lengths and effusion rates in active Hawaiian channel-fed flows. Measured tube lengths vs. effusion rate estimates were compared with data for Hawaiian channel-fed flows (Fig. 2). The two data sets overlap and have parallel trends. These results suggest that the lava tube caves studied formed by the roofing-over of channel-fed flows or had segments of channel-fed flow. We propose

  8. Lipid raft aggregation during the formation of the immunological synapse: quantitative mapping and simulations

    NASA Astrophysics Data System (ADS)

    Amador Kane, Suzanne; Adelman, Joshua; Lee, Mark; Punt, Jennifer; Ebert, Peter

    2002-03-01

    Lipid raft aggregation during formation of the immunological synapse in T-cells was explored using both experimental results from immunofluorescence imaging and computer simulations. Profiles of lipid raft distributions in the capping region relative to other protein species are presented, and compared for various experimental approaches. We also discuss a model for the dynamical formation of the synapse which incorporates different methods of transport for the lipid rafts themselves as well as other important species, including T-cell receptors and the major histocompatibility complex (MHC)/peptide complex, and we relate these to experimental findings.

  9. Primary Visual Cortex as a Saliency Map: A Parameter-Free Prediction and Its Test by Behavioral Data

    PubMed Central

    Zhaoping, Li; Zhe, Li

    2015-01-01

    It has been hypothesized that neural activities in the primary visual cortex (V1) represent a saliency map of the visual field to exogenously guide attention. This hypothesis has so far provided only qualitative predictions and their confirmations. We report this hypothesis’ first quantitative prediction, derived without free parameters, and its confirmation by human behavioral data. The hypothesis provides a direct link between V1 neural responses to a visual location and the saliency of that location to guide attention exogenously. In a visual input containing many bars, one of them saliently different from all the other bars which are identical to each other, saliency at the singleton’s location can be measured by the shortness of the reaction time in a visual search for singletons. The hypothesis predicts quantitatively the whole distribution of the reaction times to find a singleton unique in color, orientation, and motion direction from the reaction times to find other types of singletons. The prediction matches human reaction time data. A requirement for this successful prediction is a data-motivated assumption that V1 lacks neurons tuned simultaneously to color, orientation, and motion direction of visual inputs. Since evidence suggests that extrastriate cortices do have such neurons, we discuss the possibility that the extrastriate cortices play no role in guiding exogenous attention so that they can be devoted to other functions like visual decoding and endogenous attention. PMID:26441341

  10. Primary Visual Cortex as a Saliency Map: A Parameter-Free Prediction and Its Test by Behavioral Data.

    PubMed

    Zhaoping, Li; Zhe, Li

    2015-10-01

    It has been hypothesized that neural activities in the primary visual cortex (V1) represent a saliency map of the visual field to exogenously guide attention. This hypothesis has so far provided only qualitative predictions and their confirmations. We report this hypothesis' first quantitative prediction, derived without free parameters, and its confirmation by human behavioral data. The hypothesis provides a direct link between V1 neural responses to a visual location and the saliency of that location to guide attention exogenously. In a visual input containing many bars, one of them saliently different from all the other bars which are identical to each other, saliency at the singleton's location can be measured by the shortness of the reaction time in a visual search for singletons. The hypothesis predicts quantitatively the whole distribution of the reaction times to find a singleton unique in color, orientation, and motion direction from the reaction times to find other types of singletons. The prediction matches human reaction time data. A requirement for this successful prediction is a data-motivated assumption that V1 lacks neurons tuned simultaneously to color, orientation, and motion direction of visual inputs. Since evidence suggests that extrastriate cortices do have such neurons, we discuss the possibility that the extrastriate cortices play no role in guiding exogenous attention so that they can be devoted to other functions like visual decoding and endogenous attention. PMID:26441341

  11. Predictable nonwandering localization of covariant Lyapunov vectors and cluster synchronization in scale-free networks of chaotic maps.

    PubMed

    Kuptsov, Pavel V; Kuptsova, Anna V

    2014-09-01

    Covariant Lyapunov vectors for scale-free networks of Hénon maps are highly localized. We revealed two mechanisms of the localization related to full and phase cluster synchronization of network nodes. In both cases the localization nodes remain unaltered in the course of the dynamics, i.e., the localization is nonwandering. Moreover, this is predictable: The localization nodes are found to have specific dynamical and topological properties and they can be found without computing of the covariant vectors. This is an example of explicit relations between the system topology, its phase-space dynamics, and the associated tangent-space dynamics of covariant Lyapunov vectors. PMID:25314498

  12. Analysis and prediction of lightning strike distributions associated with synoptic map types over Florida

    SciTech Connect

    Reap, R.M.

    1994-08-01

    The temporal and spatial distributions of lightning activity associated with specific synoptic regimes of low-level wind flow were analyzed as part of an experiment to develop improved statistical thunderstorm forecasts for Florida. The synoptic regimes were identified by means of a linear correlation technique that was used to perform pattern classification or `map typing` of 18- and 30-h sea level pressure forecasts from the National Meteorological Center`s Nested Grid Model (NGM). Lightning location data for the 1987-90 warm seasons were subsequently analyzed on a 12-km grid to determine the thunderstorm distribution for each of the predetermined map types. The analysis revealed organized coastal maxima in lightning activity related to land-sea-breeze convergence zones that form in direct response to the low-level wind flow. Surface effects were also indicated by the persistent minima in lightning activity over Lake Okeechobee and by the lightning maxima found in regions with shoreline curvature favoring localized convergence. Experimental thunderstorm probability equations for Florida were subsequently developed from climatological lightning frequencies and NGM forecast fields. The lightning frequencies were combined with the K stability index to form interactive predictors that take into account the temporal and spatial variations in lightning occurrence for each map type but modulate the climatology in response to the daily large-scale synoptic situation. The statistical forecast equations were developed for each map type in an attempt to simulate the effects of small-scale processes, such as land-sea-breeze convergence zones, on the subsequent development of peninsular-scale convection.

  13. Prediction-area (P-A) plot and C-A fractal analysis to classify and evaluate evidential maps for mineral prospectivity modeling

    NASA Astrophysics Data System (ADS)

    Yousefi, Mahyar; Carranza, Emmanuel John M.

    2015-06-01

    There are methods of mineral prospectivity mapping whereby, besides assignment of weights to classes of evidence in an evidential map, every evidential map is also given a weight based on expert opinion. In this regard, evaluating the relative importance of every evidential map derived from particular spatial data sets is a highly subjective exercise and the assignment of meaningful weights to evidential maps usually involves a trial-and-error procedure. In this paper, we used a prediction-area (P-A) plot and normalized density to estimate weights of every evidential map. The method of P-A plot is a data-driven way, rather than using expert opinion, to evaluate and weight evidential maps.

  14. QTL mapping of root aerenchyma formation in seedlings of a rare teosinte, Zeanicaraguenis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aerenchyma cell formation in plant root systems is considered to be among one of the most important physiological root characteristics affecting flooding tolerance in species possessing such structures. In some species, aerenchyma cell development is an induced response, occurring shortly following...

  15. Maps, codes, and sequence elements: can we predict the protein output from an alternatively spliced locus?

    PubMed

    Sharma, Shalini; Black, Douglas L

    2006-11-22

    Alternative splicing choices are governed by splicing regulatory protein interactions with splicing silencer and enhancer elements present in the pre-mRNA. However, the prediction of these choices from genomic sequence is difficult, in part because the regulators can act as either enhancers or silencers. A recent study describes how for a particular neuronal splicing regulatory protein, Nova, the location of its binding sites is highly predictive of the protein's effect on an exon's splicing.

  16. Genomic Prediction for Quantitative Traits Is Improved by Mapping Variants to Gene Ontology Categories in Drosophila melanogaster.

    PubMed

    Edwards, Stefan M; Sørensen, Izel F; Sarup, Pernille; Mackay, Trudy F C; Sørensen, Peter

    2016-08-01

    Predicting individual quantitative trait phenotypes from high-resolution genomic polymorphism data is important for personalized medicine in humans, plant and animal breeding, and adaptive evolution. However, this is difficult for populations of unrelated individuals when the number of causal variants is low relative to the total number of polymorphisms and causal variants individually have small effects on the traits. We hypothesized that mapping molecular polymorphisms to genomic features such as genes and their gene ontology categories could increase the accuracy of genomic prediction models. We developed a genomic feature best linear unbiased prediction (GFBLUP) model that implements this strategy and applied it to three quantitative traits (startle response, starvation resistance, and chill coma recovery) in the unrelated, sequenced inbred lines of the Drosophila melanogaster Genetic Reference Panel. Our results indicate that subsetting markers based on genomic features increases the predictive ability relative to the standard genomic best linear unbiased prediction (GBLUP) model. Both models use all markers, but GFBLUP allows differential weighting of the individual genetic marker relationships, whereas GBLUP weighs the genetic marker relationships equally. Simulation studies show that it is possible to further increase the accuracy of genomic prediction for complex traits using this model, provided the genomic features are enriched for causal variants. Our GFBLUP model using prior information on genomic features enriched for causal variants can increase the accuracy of genomic predictions in populations of unrelated individuals and provides a formal statistical framework for leveraging and evaluating information across multiple experimental studies to provide novel insights into the genetic architecture of complex traits. PMID:27235308

  17. A statistical approach to understanding and predicting tropical storm formation in the east Pacific basin

    NASA Astrophysics Data System (ADS)

    Nelson, Dianna N.

    Despite its spatial confines, the east Pacific basin is one of the most active basins in the world for tropical cyclone (TC) genesis. While the TCs that form in the basin have important implications for Central America and the southwestern U.S., relatively little research (compared to other tropical basins) has been done on eastern Pacific tropical cyclogenesis. The present study uses two statistical techniques---linear discriminant analysis (LDA) and a Bayesian probabilistic model to identify those variables that are associated with the development of nascent vortices in the east Pacific and uses them to predict tropical storm formation for lead times out to 48 hours. All nascent vortices that last for a minimum of 48 hours and form during the 2001--2009 "peak" hurricane seasons (July-September) are considered in the study. An initial set of 27 spatially averaged variables is considered as potential predictors for the statistical models. Results from both the LDA algorithm and Bayes probabilistic model show that a number of predictors improve the forecast skill of both models. These predictors include the 900hPa relative vorticity, latitude of the vortex, 900hPa deformation fields, 900hPa-500hPa relative humidity, 900hPa zonal wind, and the 900hPa-200hPa equatorward vertical shear of the meridional wind. Using the aforementioned predictors as a basis, a composite-based conceptual model for environmental elements that favor tropical storm formation is constructed to explain the physical mechanisms of the process. In conjunction with the statistical and composite-based models, Tropical Storm Gil (a 2007 storm that is accurately forecast by the statistical models) and Tropical Storm Enrique (a 2009 case that is poorly forecast) are used to highlight the strengths and weaknesses of each model.

  18. Geologic map of the Peach Orchard Flat quadrangle, Carbon County, Wyoming, and descriptions of new stratigraphic units in the Upper Cretaceous Lance Formation and Paleocene Fort Union Formation, eastern Greater Green River Basin, Wyoming-Colorado

    USGS Publications Warehouse

    Honey, J.D.; Hettinger, R.D.

    2004-01-01

    This report provides a geologic map of the Peach Orchard Flat 7.5-minute quadrangle, located along the eastern flank of the Washakie Basin, Wyo. Geologic formations and individual coal beds were mapped at a scale of 1:24,000; surface stratigraphic sections were measured and described; and well logs were examined to determine coal correlations and thicknesses in the subsurface. In addition, four lithostratigraphic units were named: the Red Rim Member of the Upper Cretaceous Lance Formation, and the China Butte, Blue Gap, and Overland Members of the Paleocene Fort Union Formation.

  19. Berkeley Prize: Mapping the Fuel for Star Formation in Early Universe Galaxies

    NASA Astrophysics Data System (ADS)

    Tacconi, Linda

    2012-01-01

    Stars form from cold molecular interstellar gas, which is relatively rare in galaxies like the Milky Way, which form only a few new stars per year. Massive galaxies in the distant universe formed stars much more rapidly. Was star formation more efficient in the past, and/or were early galaxies richer in molecular gas? The answer was elusive when our instruments could probe molecules only in the most luminous and rare objects such as mergers and quasars. But a new survey of molecular gas in typical massive star-forming galaxies at redshifts from about 1.2 to 2.3 (corresponding to when the universe was 24% to 40% of its current age) reveals that distant star-forming galaxies were indeed molecular-gas rich and that the star-formation efficiency is not strongly dependent on cosmic epoch.

  20. Differential effects of two types of formative assessment in predicting performance of first-year medical students.

    PubMed

    Krasne, Sally; Wimmers, Paul F; Relan, Anju; Drake, Thomas A

    2006-05-01

    Formative assessments are systematically designed instructional interventions to assess and provide feedback on students' strengths and weaknesses in the course of teaching and learning. Despite their known benefits to student attitudes and learning, medical school curricula have been slow to integrate such assessments into the curriculum. This study investigates how performance on two different modes of formative assessment relate to each other and to performance on summative assessments in an integrated, medical-school environment. Two types of formative assessment were administered to 146 first-year medical students each week over 8 weeks: a timed, closed-book component to assess factual recall and image recognition, and an un-timed, open-book component to assess higher order reasoning including the ability to identify and access appropriate resources and to integrate and apply knowledge. Analogous summative assessments were administered in the ninth week. Models relating formative and summative assessment performance were tested using Structural Equation Modeling. Two latent variables underlying achievement on formative and summative assessments could be identified; a "formative-assessment factor" and a "summative-assessment factor," with the former predicting the latter. A latent variable underlying achievement on open-book formative assessments was highly predictive of achievement on both open- and closed-book summative assessments, whereas a latent variable underlying closed-book assessments only predicted performance on the closed-book summative assessment. Formative assessments can be used as effective predictive tools of summative performance in medical school. Open-book, un-timed assessments of higher order processes appeared to be better predictors of overall summative performance than closed-book, timed assessments of factual recall and image recognition. PMID:16729243

  1. Genesis of Pre-Hurricane Felix (2007). Part 2; Warm Core Formation, Precipitation Evolution, and Predictability

    NASA Technical Reports Server (NTRS)

    Wang, zhuo; Montgomery M. T.; Dunkerton, T. J.

    2010-01-01

    This is the second of a two-part study examining the simulated formation of Atlantic Hurricane Felix (2007) in a cloud-representing framework. Here several open issues are addressed concerning the formation of the storm's warm core, the evolution and respective contribution of stratiform versus convective precipitation within the parent wave's pouch, and the sensitivity of the development pathway reported in Part I to different model physics options and initial conditions. All but one of the experiments include ice microphysics as represented by one of several parameterizations, and the partition of convective versus stratiform precipitation is accomplished using a standard numerical technique based on the high-resolution control experiment. The transition to a warm-core tropical cyclone from an initially cold-core, lower tropospheric wave disturbance is analyzed first. As part of this transformation process, it is shown that deep moist convection is sustained near the pouch center. Both convective and stratiform precipitation rates increase with time. While stratiform precipitation occupies a larger area even at the tropical storm stage, deep moist convection makes a comparable contribution to the total rain rate at the pregenesis stage, and a larger contribution than stratiform processes at the storm stage. The convergence profile averaged near the pouch center is found to become dominantly convective with increasing deep moist convective activity there. Low-level convergence forced by interior diabatic heating plays a key role in forming and intensifying the near-surface closed circulation, while the midlevel convergence associated with stratiform precipitation helps to increase the midlevel circulation and thereby contributes to the formation and upward extension of a tropospheric-deep cyclonic vortex. Sensitivity tests with different model physics options and initial conditions demonstrate a similar pregenesis evolution. These tests suggest that the genesis

  2. The Use of Fluid Mechanics to Predict Regions of Microscopic Thrombus Formation in Pulsatile VADs.

    PubMed

    Topper, Stephen R; Navitsky, Michael A; Medvitz, Richard B; Paterson, Eric G; Siedlecki, Christopher A; Slattery, Margaret J; Deutsch, Steven; Rosenberg, Gerson; Manning, Keefe B

    2014-03-01

    We compare the velocity and shear obtained from particle image velocimetry (PIV) and computational fluid dynamics (CFD) in a pulsatile ventricular assist device (VAD) to further test our thrombus predictive methodology using microscopy data from an explanted VAD. To mimic physiological conditions in vitro, a mock circulatory loop is used with a blood analog that matched blood's viscoelastic behavior at 40% hematocrit. Under normal physiologic pressures and for a heart rate of 75 bpm, PIV data is acquired and wall shear maps are produced. The resolution of the PIV shear rate calculations are tested using the CFD and found to be in the same range. A bovine study, using a model of the 50 cc Penn State V-2 VAD, for 30 days at a constant beat rate of 75 beats per minute (bpm) provides the microscopic data whereby after the 30 days, the device is explanted and the sac surface analyzed using scanning electron microscopy (SEM) and, after immunofluorescent labeling for platelets and fibrin, confocal microscopy. Areas are examined based on PIV measurements and CFD, with special attention to low shear regions where platelet and fibrin deposition are most likely to occur. Data collected within the outlet port in a direction normal to the front wall of the VAD shows that some regions experience wall shear rates less than 500 s(-1), which increases the likelihood of platelet and fibrin deposition. Despite only one animal study, correlations between PIV, CFD, and in vivo data show promise. Deposition probability is quantified by the thrombus susceptibility potential, a calculation to correlate low shear and time of shear with deposition.

  3. Selected data for wells and test holes used in structure-contour maps of the Inyan Kara Group, Minnekahta Limestone, Minnelusa Formation, Madison Limestone, and Deadwood Formation in the Black Hills area, South Dakota

    USGS Publications Warehouse

    Carter, J.M.

    1999-01-01

    This report presents selected data on wells and test holes that were used in the construction of structure-contour maps of selected formations that contain major aquifers in the Black Hills area of western South Dakota. Altitudes of the top of the Inyan Kara Group, Minnekahta Limestone, Minnelusa Formation, Madison Limestone, and Deadwood Formation are presented for the wells and test holes presented in this report.

  4. Using Catalytic Atom Maps to Predict the Catalytic Functions Present in Enzyme Active Sites

    PubMed Central

    Nosrati, Geoffrey R.; Houk, K. N.

    2012-01-01

    Catalytic Atom Maps (CAMs) are minimal models of enzyme active sites. The structures in the Protein Data Bank (PDB) were examined to determine if proteins with CAM-like geometries in their active sites all share the same catalytic function. We combined the CAM-based search protocol with a filter based on the weighted contact number (WCN) of the catalytic residues, a measure of the “crowdedness” of the microenvironment around a protein residue. Using this technique, a CAM based on the Ser-His-Asp catalytic triad of trypsin was able to correctly identify catalytic triads in other enzymes within 0.5 Å RMSD of the Catalytic Atom Map with 96% accuracy. A CAM based on the Cys-Arg-(Asp/Glu) active site residues from the tyrosine phosphatase active site achieved 89% accuracy in identifying this type of catalytic functionality. Both of these Catalytic Atom Maps were able to identify active sites across different fold types. Finally, the PDB was searched to locate proteins with catalytic functionality similar to that present in the active site of orotidine 5′-monophosphate decarboxylase (ODCase), whose mechanism is not known with certainty. A CAM, based on the conserved Lys-Asp-Lys-Asp tetrad in the ODCase active site, was used to search the PDB for enzymes with similar active sites. The ODCase active site has a geometry similar to that of Schiff base-forming Class I aldolases, with lowest aldolase RMSD to the ODCase CAM at 0.48 Å. The similarity between this CAM and the aldolase active site suggests that ODCase has the correct catalytic functionality present in its active site for the generation of a nucleophilic lysine. PMID:22909276

  5. The role of cell adhesion molecules in visual circuit formation: From neurite outgrowth to maps and synaptic specificity

    PubMed Central

    Missaire, Mégane

    2015-01-01

    ABSTRACT The formation of visual circuitry is a multistep process that involves cell–cell interactions based on a range of molecular mechanisms. The correct implementation of individual events, including axon outgrowth and guidance, the formation of the topographic map, or the synaptic targeting of specific cellular subtypes, are prerequisites for a fully functional visual system that is able to appropriately process the information captured by the eyes. Cell adhesion molecules (CAMs) with their adhesive properties and their high functional diversity have been identified as key actors in several of these fundamental processes. Because of their growth‐promoting properties, CAMs play an important role in neuritogenesis. Furthermore, they are necessary to control additional neurite development, regulating dendritic spacing and axon pathfinding. Finally, trans‐synaptic interactions of CAMs ensure cell type‐specific connectivity as a basis for the establishment of circuits processing distinct visual features. Recent discoveries implicating CAMs in novel mechanisms have led to a better general understanding of neural circuit formation, but also revealed an increasing complexity of their function. This review aims at describing the different levels of action for CAMs to shape neural connectivity, with a special focus on the visual system. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 75: 569–583, 2015 PMID:25649254

  6. Predicting impact of multi-paths on phase change in map-based vehicular ad hoc networks

    NASA Astrophysics Data System (ADS)

    Rahmes, Mark; Lemieux, George; Sonnenberg, Jerome; Chester, David B.

    2014-05-01

    Dynamic Spectrum Access, which through its ability to adapt the operating frequency of a radio, is widely believed to be a solution to the limited spectrum problem. Mobile Ad Hoc Networks (MANETs) can extend high capacity mobile communications over large areas where fixed and tethered-mobile systems are not available. In one use case with high potential impact cognitive radio employs spectrum sensing to facilitate identification of allocated frequencies not currently accessed by their primary users. Primary users own the rights to radiate at a specific frequency and geographic location, secondary users opportunistically attempt to radiate at a specific frequency when the primary user is not using it. We quantify optimal signal detection in map based cognitive radio networks with multiple rapidly varying phase changes and multiple orthogonal signals. Doppler shift occurs due to reflection, scattering, and rapid vehicle movement. Path propagation as well as vehicle movement produces either constructive or destructive interference with the incident wave. Our signal detection algorithms can assist the Doppler spread compensation algorithm by deciding how many phase changes in signals are present in a selected band of interest. Additionally we can populate a spatial radio environment map (REM) database with known information that can be leveraged in an ad hoc network to facilitate Dynamic Spectrum Access. We show how topography can help predict the impact of multi-paths on phase change, as well as about the prediction from dense traffic areas. Utilization of high resolution geospatial data layers in RF propagation analysis is directly applicable.

  7. Early Prediction of Cancer Progression by Depth-Resolved Nanoscale Mapping of Nuclear Architecture from Unstained Tissue Specimens.

    PubMed

    Uttam, Shikhar; Pham, Hoa V; LaFace, Justin; Leibowitz, Brian; Yu, Jian; Brand, Randall E; Hartman, Douglas J; Liu, Yang

    2015-11-15

    Early cancer detection currently relies on screening the entire at-risk population, as with colonoscopy and mammography. Therefore, frequent, invasive surveillance of patients at risk for developing cancer carries financial, physical, and emotional burdens because clinicians lack tools to accurately predict which patients will actually progress into malignancy. Here, we present a new method to predict cancer progression risk via nanoscale nuclear architecture mapping (nanoNAM) of unstained tissue sections based on the intrinsic density alteration of nuclear structure rather than the amount of stain uptake. We demonstrate that nanoNAM detects a gradual increase in the density alteration of nuclear architecture during malignant transformation in animal models of colon carcinogenesis and in human patients with ulcerative colitis, even in tissue that appears histologically normal according to pathologists. We evaluated the ability of nanoNAM to predict "future" cancer progression in patients with ulcerative colitis who did and did not develop colon cancer up to 13 years after their initial colonoscopy. NanoNAM of the initial biopsies correctly classified 12 of 15 patients who eventually developed colon cancer and 15 of 18 who did not, with an overall accuracy of 85%. Taken together, our findings demonstrate great potential for nanoNAM in predicting cancer progression risk and suggest that further validation in a multicenter study with larger cohorts may eventually advance this method to become a routine clinical test. PMID:26383164

  8. Early Prediction of Cancer Progression by Depth-Resolved Nanoscale Mapping of Nuclear Architecture from Unstained Tissue Specimens.

    PubMed

    Uttam, Shikhar; Pham, Hoa V; LaFace, Justin; Leibowitz, Brian; Yu, Jian; Brand, Randall E; Hartman, Douglas J; Liu, Yang

    2015-11-15

    Early cancer detection currently relies on screening the entire at-risk population, as with colonoscopy and mammography. Therefore, frequent, invasive surveillance of patients at risk for developing cancer carries financial, physical, and emotional burdens because clinicians lack tools to accurately predict which patients will actually progress into malignancy. Here, we present a new method to predict cancer progression risk via nanoscale nuclear architecture mapping (nanoNAM) of unstained tissue sections based on the intrinsic density alteration of nuclear structure rather than the amount of stain uptake. We demonstrate that nanoNAM detects a gradual increase in the density alteration of nuclear architecture during malignant transformation in animal models of colon carcinogenesis and in human patients with ulcerative colitis, even in tissue that appears histologically normal according to pathologists. We evaluated the ability of nanoNAM to predict "future" cancer progression in patients with ulcerative colitis who did and did not develop colon cancer up to 13 years after their initial colonoscopy. NanoNAM of the initial biopsies correctly classified 12 of 15 patients who eventually developed colon cancer and 15 of 18 who did not, with an overall accuracy of 85%. Taken together, our findings demonstrate great potential for nanoNAM in predicting cancer progression risk and suggest that further validation in a multicenter study with larger cohorts may eventually advance this method to become a routine clinical test.

  9. Prediction of Hot Tear Formation in Vertical DC Casting of Aluminum Billets Using a Granular Approach

    NASA Astrophysics Data System (ADS)

    Sistaninia, M.; Drezet, J.-M.; Phillion, A. B.; Rappaz, M.

    2013-09-01

    A coupled hydromechanical granular model aimed at predicting hot tear formation and stress-strain behavior in metallic alloys during solidification is applied to the semicontinuous direct chill casting of aluminum alloy round billets. This granular model consists of four separate three-dimensional (3D) modules: (I) a solidification module that is used for generating the solid-liquid geometry at a given solid fraction, (II) a fluid flow module that is used to calculate the solidification shrinkage and deformation-induced pressure drop within the intergranular liquid, (III) a semisolid deformation module that is based on a combined finite element/discrete element method and simulates the rheological behavior of the granular structure, and (IV) a failure module that simulates crack initiation and propagation. To investigate hot tearing, the granular model has been applied to a representative volume within the direct chill cast billet that is located at the bottom of the liquid sump, and it reveals that semisolid deformations imposed on the mushy zone open the liquid channels due to localization of the deformation at grains boundaries. At a low casting speed, only individual pores are able to form in the widest channels because liquid feeding remains efficient. However, as the casting speed increases, the flow of liquid required to compensate for solidification shrinkage also increases and as a result the pores propagate and coalesce to form a centerline crack.

  10. Using Planet Formation Simulations to Predict the Free-floating Planet Yield Expected from WFIRST

    NASA Astrophysics Data System (ADS)

    Barclay, Thomas; Quintana, Elisa V.

    2016-06-01

    Planets are thought to form in circumstellar disks as a product of star formation. Material in the disk ends up in one of three places, (a) it remains in the disk as part of a planet, minor body or as interplanetary material, (b) it falls into the star, or (c) it is ejected from the system. We explore the properties of this ejected material using N-body simulations. We find that in planetary systems like ours (with Jupiter and Saturn) about half the ejected material is in bodies smaller than 1 Lunar-mass and about half is in bodies larger than 1 Mars-mass. The ejections happen early and no planets more massive than half an earth-mass are ejected. When no giant planets are present in the system, very little material is ejected. We predict that future space-borne microlensing searches for free-floating terrestrial-mass planets, such as WFIRST, will discover large numbers of Mars-mass planets but will not make significant detections of Earth-mass planets.

  11. NG2 expression predicts the metastasis formation in soft-tissue sarcoma patients.

    PubMed

    Benassi, Maria Serena; Pazzaglia, Laura; Chiechi, Antonella; Alberghini, Marco; Conti, Amalia; Cattaruzza, Sabrina; Wassermann, Bruna; Picci, Piero; Perris, Roberto

    2009-01-01

    Enhanced expression levels of NG2 proteoglycan in presurgical original lesions of soft-tissue sarcoma (STS) patients defines with 55% probability the immediate (i.e., within 12 months postsurgery) risk in these individuals to develop postsurgical secondary lesions, independently of any other clinical trait. It, therefore, provides a molecular factor that alone prospects a particularly unfavorable clinical outcome in such patients. Evaluation of the timing of metastasis formation in patients with high and low levels of NG2 in their primitive lesions further stratified the patients in subsets with diverse lag phases in the occurrence of metastatic disease. In our cohort of high-grade STS cases, transcription of NG2 also showed a 81-fold amplification in metastatic lesions, when compared to primitive ones, and this gene overexpression was accompanied by an abundant but nonuniform in situ expression of its product. In a similar manner as seen in primitive lesions, patients with higher levels of metastatic NG2 encountered a significantly more dismal clinical course. Multivariate analysis asserted that in these individuals upregulation of NG2 represented an absolute independent prognostic parameter. Therefore, minimally invasive assessment of the transcription levels of the NG2 gene represents a parameter capable of predicting the arising of metastatic disease within a definite postsurgery time interval, and affords in adjunct in the definition of life expectance in STS patients.

  12. Prediction of terrestrial gamma dose rate based on geological formations and soil types in the Johor State, Malaysia.

    PubMed

    Saleh, Muneer Aziz; Ramli, Ahmad Termizi; bin Hamzah, Khaidzir; Alajerami, Yasser; Moharib, Mohammed; Saeed, Ismael

    2015-10-01

    This study aims to predict and estimate unmeasured terrestrial gamma dose rate (TGDR) using statistical analysis methods to derive a model from the actual measurement based on geological formation and soil type. The measurements of TGDR were conducted in the state of Johor with a total of 3873 measured points which covered all geological formations, soil types and districts. The measurements were taken 1 m above the soil surface using NaI [Ti] detector. The measured gamma dose rates ranged from 9 nGy h(-1) to 1237 nGy h(-1) with a mean value of 151 nGy h(-1). The data have been normalized to fit a normal distribution. Tests of significance were conducted among all geological formations and soil types, using the unbalanced one way ANOVA. The results indicated strong significant differences due to the different geological formations and soil types present in Johor State. Pearson Correlation was used to measure the relations between gamma dose rate based on geological formation and soil type (D(G,S)) with the gamma dose rate based on geological formation (D(G)) or soil type (D(s)). A very good correlation was found between D(G,S) and D(G) or D(G,S) and D(s). A total of 118 pairs of geological formations and soil types were used to derive the statistical contribution of geological formations and soil types to gamma dose rates. The contribution of the gamma dose rate from geological formation and soil type were found to be 0.594 and 0.399, respectively. The null hypotheses were accepted for 83% of examined data, therefore, the model could be used to predict gamma dose rates based on geological formation and soil type information.

  13. Prediction of terrestrial gamma dose rate based on geological formations and soil types in the Johor State, Malaysia.

    PubMed

    Saleh, Muneer Aziz; Ramli, Ahmad Termizi; bin Hamzah, Khaidzir; Alajerami, Yasser; Moharib, Mohammed; Saeed, Ismael

    2015-10-01

    This study aims to predict and estimate unmeasured terrestrial gamma dose rate (TGDR) using statistical analysis methods to derive a model from the actual measurement based on geological formation and soil type. The measurements of TGDR were conducted in the state of Johor with a total of 3873 measured points which covered all geological formations, soil types and districts. The measurements were taken 1 m above the soil surface using NaI [Ti] detector. The measured gamma dose rates ranged from 9 nGy h(-1) to 1237 nGy h(-1) with a mean value of 151 nGy h(-1). The data have been normalized to fit a normal distribution. Tests of significance were conducted among all geological formations and soil types, using the unbalanced one way ANOVA. The results indicated strong significant differences due to the different geological formations and soil types present in Johor State. Pearson Correlation was used to measure the relations between gamma dose rate based on geological formation and soil type (D(G,S)) with the gamma dose rate based on geological formation (D(G)) or soil type (D(s)). A very good correlation was found between D(G,S) and D(G) or D(G,S) and D(s). A total of 118 pairs of geological formations and soil types were used to derive the statistical contribution of geological formations and soil types to gamma dose rates. The contribution of the gamma dose rate from geological formation and soil type were found to be 0.594 and 0.399, respectively. The null hypotheses were accepted for 83% of examined data, therefore, the model could be used to predict gamma dose rates based on geological formation and soil type information. PMID:26142818

  14. Map-based prediction of organic carbon in headwater streams improved by downstream observations from the river outlet

    NASA Astrophysics Data System (ADS)

    Temnerud, J.; von Brömssen, C.; Fölster, J.; Buffam, I.; Andersson, J.-O.; Nyberg, L.; Bishop, K.

    2016-01-01

    In spite of the great abundance and ecological importance of headwater streams, managers are usually limited by a lack of information about water chemistry in these headwaters. In this study we test whether river outlet chemistry can be used as an additional source of information to improve the prediction of the chemistry of upstream headwaters (size < 2 km2), relative to models based on map information alone. We use the concentration of total organic carbon (TOC), an important stream ecosystem parameter, as the target for our study. Between 2000 and 2008, we carried out 17 synoptic surveys in 9 mesoscale catchments (size 32-235 km2). Over 900 water samples were collected in total, primarily from headwater streams but also including each catchment's river outlet during every survey. First we used partial least square regression (PLS) to model the distribution (median, interquartile range (IQR)) of headwater stream TOC for a given catchment, based on a large number of candidate variables including sub-catchment characteristics from GIS, and measured river chemistry at the catchment outlet. The best candidate variables from the PLS models were then used in hierarchical linear mixed models (MM) to model TOC in individual headwater streams. Three predictor variables were consistently selected for the MM calibration sets: (1) proportion of forested wetlands in the sub-catchment (positively correlated with headwater stream TOC), (2) proportion of lake surface cover in the sub-catchment (negatively correlated with headwater stream TOC), and (3) river outlet TOC (positively correlated with headwater stream TOC). Including river outlet TOC improved predictions, with 5-15 % lower prediction errors than when using map information alone. Thus, data on water chemistry measured at river outlets offer information which can complement GIS-based modelling of headwater stream chemistry.

  15. Predictive mapping of seabirds, pinnipeds and cetaceans off the Pacific Coast of Washington

    USGS Publications Warehouse

    Menza, Charles; Leirness, Jeffery B.; White, Tim; Winship, Arliss; Kinlan, Brian P.; Kracker, Laura; Zamon, Jeannette E.; Ballance, Lisa; Becker, Elizabeth; Forney, Karin A.; Barlow, Jay; Adams, Josh; Pereksta, David; Pearson, Scott; Pierce, John; Jeffries, Steven J.; Calambokidis, John; Douglas, Annie; Hanson, Bradford C.; Benson, Scott R.; Antrim, Liam

    2016-01-01

    This research supports the National Oceanic and Atmospheric Administration (NOAA) Coastal Zone Management Program, a voluntary partnership between the federal government and U.S. coastal and Great Lakes states and territories authorized by the Coastal Zone Management Act (CZMA) of 1972 to address national coastal issues. The act provides the basis for protecting, restoring, and responsibly developing our nation’s diverse coastal communities and resources. To meet the goals of the CZMA, the national program takes a comprehensive approach to coastal resource management – balancing the often competing and occasionally conflicting demands of coastal resource use, economic development, and conservation. A wide range of issues are addressed through the program, including coastal development, water quality, public access, habitat protection, energy facility siting, ocean governance and planning, coastal hazards, and climate change. Accurate maps of seabird and marine mammal distributions are an important tool for making informed management decisions that affect all of these issues. 

  16. Taxi-Aware Map: Identifying and Predicting Vacant Taxis in the City

    NASA Astrophysics Data System (ADS)

    Phithakkitnukoon, Santi; Veloso, Marco; Bento, Carlos; Biderman, Assaf; Ratti, Carlo

    Knowing where vacant taxis are and will be at a given time and location helps the users in daily planning and scheduling, as well as the taxi service providers in dispatching. In this paper, we present a predictive model for the number of vacant taxis in a given area based on time of the day, day of the week, and weather condition. The history is used to build the prior probability distributions for our inference engine, which is based on the naïve Bayesian classifier with developed error-based learning algorithm and method for detecting adequacy of historical data using mutual information. Based on 150 taxis in Lisbon, Portugal, we are able to predict for each hour with the overall error rate of 0.8 taxis per 1x1 km2 area.

  17. Mapping developmental precursors of cyber-aggression: trajectories of risk predict perpetration and victimization.

    PubMed

    Modecki, Kathryn L; Barber, Bonnie L; Vernon, Lynette; Vernon, Lynnette

    2013-05-01

    Technologically mediated contexts are social arenas in which adolescents can be both perpetrators and victims of aggression. Yet, there remains little understanding of the developmental etiology of cyber aggression, itself, as experienced by either perpetrators or victims. The current study examines 3-year latent within-person trajectories of known correlates of cyber-aggression: problem behavior, (low) self-esteem, and depressed mood, in a large and diverse sample of youth (N = 1,364; 54.6% female; 12-14 years old at T1). Findings demonstrate that developmental increases in problem behavior across grades 8-10 predict both cyber-perpetration and victimization in grade 11. Developmental decreases in self-esteem also predicted both grade 11 perpetration and victimization. Finally, early depressed mood predicted both perpetration and victimization later on, regardless of developmental change in depressed mood in the interim. Our results reveal a clear link between risky developmental trajectories across the early high school years and later cyber-aggression and imply that mitigating trajectories of risk early on may lead to decreases in cyber-aggression at a later date.

  18. Growth, inactivation and histamine formation of Morganella psychrotolerans and Morganella morganii - development and evaluation of predictive models.

    PubMed

    Emborg, Jette; Dalgaard, Paw

    2008-12-10

    Mathematical models for growth, heat inactivation and histamine formation by Morganella psychrotolerans and Morganella morganii were studied to evaluate the importance of these bacteria in seafood. Curves for growth and histamine formation by M. psychrotolerans in broth and seafood were generated at constant and changing storage temperatures (n=12). Observed and predicted times to formation of 100, 500 and 2000 ppm histamine were used for evaluation of an existing M. psychrotolerans histamine formation model [Emborg, J., Dalgaard, P., 2008-this issue-this issue. Modelling and predicting the growth and histamine formation by Morganella psychrotolerans. International Journal of Food Microbiology. doi:10.1016/j.ijfoodmicro.2008.08.016] Growth rates for M. psychrotolerans and M. morganii were determined at different constant temperatures from 0 degrees C to 42.5 degrees C whereas heat inactivation was studied between 37.5 degrees C and 60 degrees C. A M. morganii growth and histamine formation model was developed by combining these new data (growth rate model) and data from the existing literature (maximum population density and yield factor for histamine formation). The developed M. morganii model was evaluated by comparison of predicted growth and histamine formation with data from the existing literature. Observed and predicted growth rates for M. psychrotolerans, at constant temperatures, were similar with bias- and accuracy factor values of 1.15 and 1.45, respectively (n=11). On average times to formation of critical concentrations of histamine by M. psychrotolerans were acceptably predicted but the model was not highly accurate. Nevertheless, predictions seemed useful to support decisions concerning safe shelf-life in relation to formulation, storage and distribution of chilled seafood. Parameters for the effect of temperature on growth and inactivation of M. psychrotolerans and M. morganii differed markedly with Tmin of -8.3 to -5.9 degrees C vs. 0.3 to 2

  19. Geologic Map of Upper Cretaceous and Tertiary Strata and Coal Stratigraphy of the Paleocene Fort Union Formation, Rawlins-Little Snake River Area, South-Central Wyoming

    USGS Publications Warehouse

    Hettinger, R.D.; Honey, J.G.; Ellis, M.S.; Barclay, C.S.V.; East, J.A.

    2008-01-01

    This report provides a map and detailed descriptions of geologic formations for a 1,250 square mile region in the Rawlins-Little Snake River coal field in the eastern part of the Washakie and Great Divide Basins of south-central Wyoming. Mapping of geologic formations and coal beds was conducted at a scale of 1:24,000 and compiled at a scale of 1:100,000. Emphasis was placed on coal-bearing strata of the China Butte and Overland Members of the Paleocene Fort Union Formation. Surface stratigraphic sections were measured and described and well logs were examined to determine the lateral continuity of individual coal beds; the coal-bed stratigraphy is shown on correlation diagrams. A structure contour and overburden map constructed on the uppermost coal bed in the China Butte Member is also provided.

  20. Efficient Inverse Isoparametric Mapping Algorithm for Whole-Body Computed Tomography Registration Using Deformations Predicted by Nonlinear Finite Element Modeling

    PubMed Central

    Li, Mao; Wittek, Adam; Miller, Karol

    2014-01-01

    Biomechanical modeling methods can be used to predict deformations for medical image registration and particularly, they are very effective for whole-body computed tomography (CT) image registration because differences between the source and target images caused by complex articulated motions and soft tissues deformations are very large. The biomechanics-based image registration method needs to deform the source images using the deformation field predicted by finite element models (FEMs). In practice, the global and local coordinate systems are used in finite element analysis. This involves the transformation of coordinates from the global coordinate system to the local coordinate system when calculating the global coordinates of image voxels for warping images. In this paper, we present an efficient numerical inverse isoparametric mapping algorithm to calculate the local coordinates of arbitrary points within the eight-noded hexahedral finite element. Verification of the algorithm for a nonparallelepiped hexahedral element confirms its accuracy, fast convergence, and efficiency. The algorithm's application in warping of the whole-body CT using the deformation field predicted by means of a biomechanical FEM confirms its reliability in the context of whole-body CT registration. PMID:24828796

  1. Biofilm Formation Mechanisms of Pseudomonas aeruginosa Predicted via Genome-Scale Kinetic Models of Bacterial Metabolism.

    PubMed

    Vital-Lopez, Francisco G; Reifman, Jaques; Wallqvist, Anders

    2015-10-01

    A hallmark of Pseudomonas aeruginosa is its ability to establish biofilm-based infections that are difficult to eradicate. Biofilms are less susceptible to host inflammatory and immune responses and have higher antibiotic tolerance than free-living planktonic cells. Developing treatments against biofilms requires an understanding of bacterial biofilm-specific physiological traits. Research efforts have started to elucidate the intricate mechanisms underlying biofilm development. However, many aspects of these mechanisms are still poorly understood. Here, we addressed questions regarding biofilm metabolism using a genome-scale kinetic model of the P. aeruginosa metabolic network and gene expression profiles. Specifically, we computed metabolite concentration differences between known mutants with altered biofilm formation and the wild-type strain to predict drug targets against P. aeruginosa biofilms. We also simulated the altered metabolism driven by gene expression changes between biofilm and stationary growth-phase planktonic cultures. Our analysis suggests that the synthesis of important biofilm-related molecules, such as the quorum-sensing molecule Pseudomonas quinolone signal and the exopolysaccharide Psl, is regulated not only through the expression of genes in their own synthesis pathway, but also through the biofilm-specific expression of genes in pathways competing for precursors to these molecules. Finally, we investigated why mutants defective in anthranilate degradation have an impaired ability to form biofilms. Alternative to a previous hypothesis that this biofilm reduction is caused by a decrease in energy production, we proposed that the dysregulation of the synthesis of secondary metabolites derived from anthranilate and chorismate is what impaired the biofilms of these mutants. Notably, these insights generated through our kinetic model-based approach are not accessible from previous constraint-based model analyses of P. aeruginosa biofilm

  2. Predicting the formation and the dispersion of toxic combustion products from the fires of dangerous substances

    NASA Astrophysics Data System (ADS)

    Nevrlý, V.; Bitala, P.; Danihelka, P.; Dobeš, P.; Dlabka, J.; Hejzlar, T.; Baudišová, B.; Míček, D.; Zelinger, Z.

    2012-04-01

    Natural events, such as wildfires, lightning or earthquakes represent a frequent trigger of industrial fires involving dangerous substances. Dispersion of smoke plume from such fires and the effects of toxic combustion products are one of the reference scenarios expected in the framework of major accident prevention. Nowadays, tools for impact assessment of these events are rather missing. Detailed knowledge of burning material composition, atmospheric conditions, and other factors are required in order to describe quantitatively the source term of toxic fire products and to evaluate the parameters of smoke plume. Nevertheless, an assessment of toxic emissions from large scale fires involves a high degree of uncertainty, because of the complex character of physical and chemical processes in the harsh environment of uncontrolled flame. Among the others, soot particle formation can be mentioned as still being one of the unresolved problems in combustion chemistry, as well as decomposition pathways of chemical substances. Therefore, simplified approach for estimating the emission factors from outdoor fires of dangerous chemicals, utilizable for major accident prevention and preparedness, was developed and the case study illustrating the application of the proposed method was performed. ALOFT-FT software tool based on large eddy simulation of buoyant fire plumes was employed for predicting the local toxic contamination in the down-wind vicinity of the fire. The database of model input parameters can be effectively modified enabling the simulation of the smoke plume from pool fires or jet fires of arbitrary flammable (or combustible) gas, liquid or solid. This work was supported by the Ministry of Education, Youth and Sports of the Czech Republic via the project LD11012 (in the frame of the COST CM0901 Action) and the Ministry of Environment of the Czech Republic (project no. SPII 1a10 45/70).

  3. Biofilm Formation Mechanisms of Pseudomonas aeruginosa Predicted via Genome-Scale Kinetic Models of Bacterial Metabolism

    PubMed Central

    Vital-Lopez, Francisco G.; Reifman, Jaques; Wallqvist, Anders

    2015-01-01

    A hallmark of Pseudomonas aeruginosa is its ability to establish biofilm-based infections that are difficult to eradicate. Biofilms are less susceptible to host inflammatory and immune responses and have higher antibiotic tolerance than free-living planktonic cells. Developing treatments against biofilms requires an understanding of bacterial biofilm-specific physiological traits. Research efforts have started to elucidate the intricate mechanisms underlying biofilm development. However, many aspects of these mechanisms are still poorly understood. Here, we addressed questions regarding biofilm metabolism using a genome-scale kinetic model of the P. aeruginosa metabolic network and gene expression profiles. Specifically, we computed metabolite concentration differences between known mutants with altered biofilm formation and the wild-type strain to predict drug targets against P. aeruginosa biofilms. We also simulated the altered metabolism driven by gene expression changes between biofilm and stationary growth-phase planktonic cultures. Our analysis suggests that the synthesis of important biofilm-related molecules, such as the quorum-sensing molecule Pseudomonas quinolone signal and the exopolysaccharide Psl, is regulated not only through the expression of genes in their own synthesis pathway, but also through the biofilm-specific expression of genes in pathways competing for precursors to these molecules. Finally, we investigated why mutants defective in anthranilate degradation have an impaired ability to form biofilms. Alternative to a previous hypothesis that this biofilm reduction is caused by a decrease in energy production, we proposed that the dysregulation of the synthesis of secondary metabolites derived from anthranilate and chorismate is what impaired the biofilms of these mutants. Notably, these insights generated through our kinetic model-based approach are not accessible from previous constraint-based model analyses of P. aeruginosa biofilm

  4. Looking Back and Looking Forward: Reprising the Promise and Predicting the Future of Formation Flying and Spaceborne GPS Navigation Systems

    NASA Technical Reports Server (NTRS)

    Bauer, Frank H.; Dennehy, Neil

    2015-01-01

    A retrospective consideration of two 15-year old Guidance, Navigation and Control (GN&C) technology 'vision' predictions will be the focus of this paper. A look back analysis and critique of these late 1990s technology roadmaps out-lining the future vision, for two then nascent, but rapidly emerging, GN&C technologies will be performed. Specifically, these two GN&C technologies were: 1) multi-spacecraft formation flying and 2) the spaceborne use and exploitation of global positioning system (GPS) signals to enable formation flying. This paper reprises the promise of formation flying and spaceborne GPS as depicted in the cited 1999 and 1998 papers. It will discuss what happened to cause that promise to be mostly unfulfilled and the reasons why the envisioned formation flying dream has yet to become a reality. The recent technology trends over the past few years will then be identified and a renewed government interest in spacecraft formation flying/cluster flight will be highlighted. The authors will conclude with a reality-tempered perspective, 15 years after the initial technology roadmaps were published, predicting a promising future of spacecraft formation flying technology development over the next decade.

  5. Map Formation in the Olfactory Bulb by Axon Guidance of Olfactory Neurons

    PubMed Central

    Auffarth, Benjamin; Kaplan, Bernhard; Lansner, Anders

    2011-01-01

    The organization of representations in the brain has been observed to locally reflect subspaces of inputs that are relevant to behavioral or perceptual feature combinations, such as in areas receptive to lower and higher-order features in the visual system. The early olfactory system developed highly plastic mechanisms and convergent evidence indicates that projections from primary neurons converge onto the glomerular level of the olfactory bulb (OB) to form a code composed of continuous spatial zones that are differentially active for particular physico-chemical feature combinations, some of which are known to trigger behavioral responses. In a model study of the early human olfactory system, we derive a glomerular organization based on a set of real-world, biologically relevant stimuli, a distribution of receptors that respond each to a set of odorants of similar ranges of molecular properties, and a mechanism of axon guidance based on activity. Apart from demonstrating activity-dependent glomeruli formation and reproducing the relationship of glomerular recruitment with concentration, it is shown that glomerular responses reflect similarities of human odor category perceptions and that further, a spatial code provides a better correlation than a distributed population code. These results are consistent with evidence of functional compartmentalization in the OB and could suggest a function for the bulb in encoding of perceptual dimensions. PMID:22013417

  6. Predicting Hip Fracture Type With Cortical Bone Mapping (CBM) in the Osteoporotic Fractures in Men (MrOS) Study.

    PubMed

    Treece, Graham M; Gee, Andrew H; Tonkin, Carol; Ewing, Susan K; Cawthon, Peggy M; Black, Dennis M; Poole, Kenneth E S

    2015-11-01

    Hip fracture risk is known to be related to material properties of the proximal femur, but fracture prediction studies adding richer quantitative computed tomography (QCT) measures to dual-energy X-ray (DXA)-based methods have shown limited improvement. Fracture types have distinct relationships to predictors, but few studies have subdivided fracture into types, because this necessitates regional measurements and more fracture cases. This work makes use of cortical bone mapping (CBM) to accurately assess, with no prior anatomical presumptions, the distribution of properties related to fracture type. CBM uses QCT data to measure the cortical and trabecular properties, accurate even for thin cortices below the imaging resolution. The Osteoporotic Fractures in Men (MrOS) study is a predictive case-cohort study of men over 65 years old: we analyze 99 fracture cases (44 trochanteric and 55 femoral neck) compared to a cohort of 308, randomly selected from 5994. To our knowledge, this is the largest QCT-based predictive hip fracture study to date, and the first to incorporate CBM analysis into fracture prediction. We show that both cortical mass surface density and endocortical trabecular BMD are significantly different in fracture cases versus cohort, in regions appropriate to fracture type. We incorporate these regions into predictive models using Cox proportional hazards regression to estimate hazard ratios, and logistic regression to estimate area under the receiver operating characteristic curve (AUC). Adding CBM to DXA-based BMD leads to a small but significant (p < 0.005) improvement in model prediction for any fracture, with AUC increasing from 0.78 to 0.79, assessed using leave-one-out cross-validation. For specific fracture types, the improvement is more significant (p < 0.0001), with AUC increasing from 0.71 to 0.77 for trochanteric fractures and 0.76 to 0.82 for femoral neck fractures. In contrast, adding DXA-based BMD to a CBM-based predictive model

  7. Usefulness of voxel-based lesion mapping for predicting motor recovery in subjects with basal ganglia hemorrhage

    PubMed Central

    Kim, Dae Hyun; Kyeong, Sunghyon; Cho, Yoona; Jung, Tae-min; Ahn, Sung Jun; Park, Yoon Ghil

    2016-01-01

    Abstract It is important to estimate motor recovery in the early phase after stroke. Many studies have demonstrated that both diffusion tensor tractography (DTT) and motor-evoked potentials (MEP) are valuable predictors of motor recovery, but these modalities do not directly reflect the status of the injured gray matter. We report on 2 subjects with basal ganglia hemorrhage who showed similar DTT and MEP findings, but had markedly different clinical outcomes. Specifically, Subject 1 showed no improvement in motor function, whereas Subject 2 exhibited substantial improvement 7 weeks after onset. To determine if differences in gray matter might lend insight into these different outcomes, we analyzed gray matter lesions of the 2 subjects using a novel voxel-based lesion mapping method. The lesion of Subject 1 mainly included the putamen, thalamus, and Heschl's gyri, indicating extension of the hemorrhage in the posterior direction. In contrast, the lesion of Subject 2 mainly included the putamen, insula, and pallidum, indicating that the hemorrhage extended anterior laterally. These differential findings suggest that voxel-based gray matter lesion mapping may help to predict differential motor recovery in subjects with basal ganglia hemorrhage with similar DTT and MEP findings. PMID:27281090

  8. Development of a predicted physical map of microsatellite locus positions for pinnipeds, with wider applicability to the Carnivora.

    PubMed

    Osborne, Amy J; Brauning, Rudiger; Schultz, Jennifer K; Kennedy, Martin A; Slate, Jon; Gemmell, Neil J

    2011-05-01

    Understanding genetic variation responsible for phenotypic differences in natural populations is significantly hampered by a lack of genomic data for many species. Levels of variation can, however, be estimated using microsatellite markers, which may be useful for relating individual fitness to genetic diversity. Prior studies have demonstrated correlations between heterozygosity and individual fitness in some species. These correlations are sometimes driven by a subset of markers, and it is unclear whether this is because those markers best reflect genome-wide heterozygosity, or whether they are linked to fitness-related genes. Differentiating between these scenarios is hindered when the genomic location of markers is unknown. Here, we develop a predicted genomic map of pinniped microsatellite loci based on conservation of primary sequence and genomic location between dog, cat and giant panda. We mapped 210 of 260 (81%) microsatellites from pinnipeds to locations in dog, cat and giant panda genomes. Based on the demonstrable synteny between the genomes of closely related taxa within the Carnivora, we use these data to identify those microsatellites with the greatest chance of cross-species amplification success and demonstrate successful amplification of 21 of 26 loci for cat, dog and two seal species. We also demonstrate the potential to identify candidate genes that may underpin the functional relationship with individual fitness. Overall, we show that this approach provides a rapid and robust method to elucidate genome organisation for nonmodel organisms and have established a resource that facilitates further genetic research on pinnipeds that also has wider applicability to other carnivores.

  9. REGIONAL PARADOX FORMATION STRUCTURE AND ISOCHORE MAPS, BLANDING SUB-BASIN, UTAH

    SciTech Connect

    Kevin McClure; Craig D. Morgan; Thomas C. Chidsey Jr.; David E. Eby

    2003-12-01

    Over 400 million barrels (64 million m{sup 3}) of oil have been produced from the shallow-shelf carbonate reservoirs in the Pennsylvanian (Desmoinesian) Paradox Formation in the Paradox Basin, Utah and Colorado. With the exception of the giant Greater Aneth field, the other 100 plus oil fields in the basin typically contain 2 to 10 million barrels (0.3-1.6 million m{sup 3}) of original oil in place. Most of these fields are characterized by high initial production rates followed by a very short productive life (primary), and hence premature abandonment. Only 15 to 25 percent of the original oil in place is recoverable during primary production from conventional vertical wells. An extensive and successful horizontal drilling program has been conducted in the giant Greater Aneth field (figure 1). However, to date, only two horizontal wells have been drilled in small Ismay and Desert Creek fields. The results from these wells were disappointing due to poor understanding of the carbonate facies and diagenetic fabrics that create reservoir heterogeneity. These small fields, and similar fields in the basin, are at high risk of premature abandonment. At least 200 million barrels (31.8 million m{sup 3}) of oil will be left behind in these small fields because current development practices leave compartments of the heterogeneous reservoirs undrained. Through proper geological evaluation of the reservoirs, production may be increased by 20 to 50 percent through the drilling of low-cost single or multilateral horizontal legs from existing vertical development wells. In addition, horizontal drilling from existing wells minimizes surface disturbances and costs for field development, particularly in the environmentally sensitive areas of southeastern Utah and southwestern Colorado.

  10. Map-based prediction of organic carbon in headwaters streams improved by downstream observations from the river outlet

    NASA Astrophysics Data System (ADS)

    Temnerud, J.; von Brömssen, C.; Fölster, J.; Buffam, I.; Andersson, J.-O.; Nyberg, L.; Bishop, K.

    2015-06-01

    In spite of the great abundance and ecological importance of headwater streams, managers are usually limited by a lack of information about water chemistry in these headwaters. In this study we test whether river outlet chemistry can be used as an additional source of information to improve the prediction of the chemistry of upstream headwaters (size < 2 km2), relative to models based on map information alone. Between 2000 and 2008, we conducted 17 synoptic surveys of streams within 9 mesoscale catchments (size 32-235 km2). Over 900 water samples were collected from catchments ranging in size from 0.03 to 235 km2. First we used partial least square regression (PLS) to model headwater stream total organic carbon (TOC) median and interquartile values for a given catchment, based on a large number of candidate variables including catchment characteristics from GIS, and measured chemistry at the catchment outlet. The best candidate variables from the PLS models were then used in hierarchical linear mixed models (MM) to model TOC in individual headwater streams. Three predictor variables were consistently selected for the MM calibration sets: (1) proportion of forested wetlands in the sub-catchment (positively correlated with headwater stream TOC), (2) proportion of lake surface cover in the sub-catchment (negatively correlated with headwater stream TOC), and (3) whole-catchment river outlet TOC (positively correlated with headwater stream TOC). Including river outlet TOC as a predictor in the models gave 5-15% lower prediction errors than using map information alone. Thus, data on water chemistry measured at river outlets offers information which can complement GIS-based modelling of headwater stream chemistry.

  11. 5D Modelling: An Efficient Approach for Creating Spatiotemporal Predictive 3D Maps of Large-Scale Cultural Resources

    NASA Astrophysics Data System (ADS)

    Doulamis, A.; Doulamis, N.; Ioannidis, C.; Chrysouli, C.; Grammalidis, N.; Dimitropoulos, K.; Potsiou, C.; Stathopoulou, E.-K.; Ioannides, M.

    2015-08-01

    Outdoor large-scale cultural sites are mostly sensitive to environmental, natural and human made factors, implying an imminent need for a spatio-temporal assessment to identify regions of potential cultural interest (material degradation, structuring, conservation). On the other hand, in Cultural Heritage research quite different actors are involved (archaeologists, curators, conservators, simple users) each of diverse needs. All these statements advocate that a 5D modelling (3D geometry plus time plus levels of details) is ideally required for preservation and assessment of outdoor large scale cultural sites, which is currently implemented as a simple aggregation of 3D digital models at different time and levels of details. The main bottleneck of such an approach is its complexity, making 5D modelling impossible to be validated in real life conditions. In this paper, a cost effective and affordable framework for 5D modelling is proposed based on a spatial-temporal dependent aggregation of 3D digital models, by incorporating a predictive assessment procedure to indicate which regions (surfaces) of an object should be reconstructed at higher levels of details at next time instances and which at lower ones. In this way, dynamic change history maps are created, indicating spatial probabilities of regions needed further 3D modelling at forthcoming instances. Using these maps, predictive assessment can be made, that is, to localize surfaces within the objects where a high accuracy reconstruction process needs to be activated at the forthcoming time instances. The proposed 5D Digital Cultural Heritage Model (5D-DCHM) is implemented using open interoperable standards based on the CityGML framework, which also allows the description of additional semantic metadata information. Visualization aspects are also supported to allow easy manipulation, interaction and representation of the 5D-DCHM geometry and the respective semantic information. The open source 3DCity

  12. Using catalytic atom maps to predict the catalytic functions present in enzyme active sites.

    PubMed

    Nosrati, Geoffrey R; Houk, K N

    2012-09-18

    Catalytic atom maps (CAMs) are minimal models of enzyme active sites. The structures in the Protein Data Bank (PDB) were examined to determine if proteins with CAM-like geometries in their active sites all share the same catalytic function. We combined the CAM-based search protocol with a filter based on the weighted contact number (WCN) of the catalytic residues, a measure of the "crowdedness" of the microenvironment around a protein residue. Using this technique, a CAM based on the Ser-His-Asp catalytic triad of trypsin was able to correctly identify catalytic triads in other enzymes within 0.5 Å rmsd of the CAM with 96% accuracy. A CAM based on the Cys-Arg-(Asp/Glu) active site residues from the tyrosine phosphatase active site achieved 89% accuracy in identifying this type of catalytic functionality. Both of these CAMs were able to identify active sites across different fold types. Finally, the PDB was searched to locate proteins with catalytic functionality similar to that present in the active site of orotidine 5'-monophosphate decarboxylase (ODCase), whose mechanism is not known with certainty. A CAM, based on the conserved Lys-Asp-Lys-Asp tetrad in the ODCase active site, was used to search the PDB for enzymes with similar active sites. The ODCase active site has a geometry similar to that of Schiff base-forming Class I aldolases, with lowest aldolase rmsd to the ODCase CAM at 0.48 Å. The similarity between this CAM and the aldolase active site suggests that ODCase has the correct catalytic functionality present in its active site for the generation of a nucleophilic lysine. PMID:22909276

  13. Rift Valley Fever Prediction and Risk Mapping: 2014-2015 Season

    NASA Technical Reports Server (NTRS)

    Anyamba, Assaf

    2015-01-01

    Extremes in either direction (+-) of precipitation temperature have significant implications for disease vectors and pathogen emergence and spread Magnitude of ENSO influence on precipitation temperature cannot be currently predicted rely on average history and patterns. Timing of event and emergence disease can be exploited (GAP) in to undertake vector control and preparedness measures. Currently - no risk for ecologically-coupled RVFV activity however we need to be vigilant during the coming fall season due the ongoing buildup of energy in the central Pacific Ocean. Potential for the dual-use of the RVF Monitor system for other VBDs Need to invest in early ground surveillance and the use of rapid field diagnostic capabilities for vector identification and virus isolation.

  14. Nodal predictive error model and Bayesian approach for thermal diffusivity and heat source mapping

    NASA Astrophysics Data System (ADS)

    Massard, H.; Fudym, Olivier; Orlande, H. R. B.; Batsale, J. C.

    2010-07-01

    This article aims at solving a two-dimensional inverse heat conduction problem in order to retrieve both the thermal diffusivity and heat source field in a thin plate. A spatial random heat pulse is applied to the plate and the thermal response is analysed. The inverse approach is based on the minimisation of a nodal predictive error model, which yields a linear estimation problem. As a result of this approach, the sensitivity matrix is directly filled with experimental data, and thus is partially noisy. Bayesian estimators, such as the Maximum A Posteriori and a Markov Chain Monte Carlo approach (Metropolis-Hastings), are implemented and compared with the Ordinary Least Squares solution. Simulated temperature measurements are used in the inverse analysis. The nodal strategy relies on the availability of temperature measurements with fine spatial resolution and high frequency, typical of nowadays infrared cameras. The effects of both the measurement errors and of the model errors on the inverse problem solution are also analysed.

  15. High-resolution predictive mapping for Rhipicephalus appendiculatus (Acari: Ixodidae) in the Horn of Africa.

    PubMed

    Leta, Samson; De Clercq, Eva M; Madder, Maxime

    2013-08-01

    The brown ear tick Rhipicephalus appendiculatus, vector of East Coast fever (ECF) and related cattle diseases caused by Theileria parva has never been reported from the Horn of Africa. Habitat suitability for this tick species was predicted using Maxent modelling technique based on R. appendiculatus records in Sub-Saharan Africa. Two models were developed: the first is based on the tropical R. appendiculatus distribution and the one is based on the distribution records in the temperate region of Sub-Saharan Africa. The tropical model shows favourable habitat in much of the Ethiopian highlands. The whole Djibouti, the south eastern Ethiopian lowlands, majority of Somalia and Eritrea were found to be not suitable for the survival and development of this tick species. Highly suitable areas occur in areas which have moderate temperature and high precipitation. Introductions of R. appendiculatus into the Horn of Africa probably have been prevented by the natural barrier between the known R. appendiculatus distribution range in East Africa and the Horn of Africa. The effect of an introduction of R. appendiculatus and thereby ECF into the Horn of Africa could be catastrophic since the cattle in this area have no immunity against ECF, and mortality might be considerable in all age groups of cattle. PMID:23413173

  16. A 21st century approach to tackling dengue: Crowdsourced surveillance, predictive mapping and tailored communication.

    PubMed

    Lwin, May O; Vijaykumar, Santosh; Fernando, Owen Noel Newton; Cheong, Siew Ann; Rathnayake, Vajira Sampath; Lim, Gentatsu; Theng, Yin-Leng; Chaudhuri, Subhasis; Foo, Schubert

    2014-02-01

    This paper describes a social media system to prevent dengue in Sri Lanka and potentially in the rest of the South and Southeast Asia regions. The system integrates three concepts of public health prevention that have thus far been implemented only in silos. First, the predictive surveillance component uses a computer simulation to forewarn health authorities and the general public about impending disease outbreaks. The civic engagement component allows the general public to use social media tools to interact and engage with health authorities by aiding them in surveillance efforts by reporting symptoms, mosquito bites and breeding sites using smartphone technologies. The health communication component utilizes citizen data gathered from the first two components to disseminate customized health awareness messages to enhance knowledge and increase preventive behaviors among citizens. The system, known as "Mo-Buzz," will be made available on a host of digital platforms like simple mobile phones, smart phones and a website. We present challenges and lessons learnt including content validation, stakeholder collaborations and applied trans-disciplinary research.

  17. An attempt to theoretically predict third-phase formation in the dimethyldibutyltetradecylmalonamide (DMDBTDMA)/dodecane/water/nitric acid extraction system

    SciTech Connect

    LeFrancois, L.; Tondre, C.; Belnet, F.; Noel, D.

    1999-03-01

    The formation of a third phase in solvent extraction (due to splitting of the organic phase into two layers) often occurs when the aqueous phase is highly concentrated in acids. This has been reported with the extraction system dimethyldibutyltetradecylmalonamide (DMDBTDMA)/n-dodecane/water/nitric acid, both in the presence and absence of metal ions. Whereas many experimental efforts have been made to investigate the effects of different parameters on third-phase formation, very few attempts have been made to predict this phenomenon on theoretical grounds. Because the part played by aggregation of the extractant molecules is recognized, the authors propose a new predictive approach based on the use of the Flory-Huggins theory of polymer solutions, which had been successfully applied for the prediction of phase separation phenomena in nonionic surfactant solutions. The authors show that this model can provide an excellent prediction of the demixing curve (in the absence of metal ions) when establishing the relation between the interaction parameter {chi}{sub 12} calculated from this theory and the nitric acid content of the aqueous phase. Apparent values of the solubility parameter {delta}{sub 2} of the diamide extractant at different acid loadings have been calculated, from which the effect of the nature of the diluent can also be very nicely predicted.

  18. Geologic mapping as a method for the construction of a detailed and testable lithostratigraphic model for the Upper Triassic Chinle Formation of Petrified Forest National Park, Arizona

    NASA Astrophysics Data System (ADS)

    Skinner, L. A.; Martz, J. W.; Parker, W.; Raucci, J.; Umhoefer, P. J.

    2010-12-01

    The Upper Triassic Chinle Formation in Petrified Forest National Park represents some of the most intensively studied Upper Triassic strata in western North America. Five stratigraphic members are exposed within the park, from oldest to youngest: the Mesa Redondo, Blue Mesa, Sonsela, Petrified Forest, and Owl Rock Members. Despite numerous stratigraphic studies of the Chinle Formation and two attempts at mapping the park over the past sixty years, sandstone marker beds in the Sonsela Member at the north and south ends of the park were still poorly mapped and correlated. Studies in the years 2002 and 2006 claimed that two sandstones which previous workers had considered to lie at different stratigraphic levels (the Jasper Forest Bed and the Flattops One sandstones in the Martha’s Butte beds) were actually correlative. This correlation resulted in a three-part division of the Sonsela Member and had a major impact on vertebrate biostratigraphy. In a recent attempt to resolve confusions regarding Chinle Formation lithostratigraphy and biostratigraphy, we have completely walked out lithologic contacts through most of the park. The resulting new geologic map, revised lithostratigraphic model, and associated data resolves the 2002 and 2006 miscorrelations by demonstrating that the Jasper Forest Bed capping Blue Mesa and Agate Mesa and Flattops One sandstones (Martha’s Butte beds) are stratigraphically distinct, resulting in a thicker and more complex five-part model for the Sonsela Member, and considerably modifying the vertebrate biostratigraphy. New geologic mapping also resulted in a detailed lithostratigraphic framework for the northern park which has previously been poorly understood, and several important new marker beds, including a purple-gray bed that represents the base of the Owl Rock Member. The revised geologic map is an ArcGIS product that includes an updated lithostratigraphic model for the Chinle Formation, fossil localities, and hyperlinks to labeled

  19. MAPPING SPATIAL/TEMPORAL DISTRIBUTIONS OF GREEN MACROALGAE IN A PACIFIC NORTHWEST COASTAL ESTUARY VIA SMALL FORMAT COLOR INFRARED AERIAL PHOTOGRAPHY

    EPA Science Inventory

    A small format 35 mm hand-held camera with color infrared slide film was used to map blooms of benthic green macroalgae upon mudflats of Yaquina Bay estuary on the central Oregon coast, U.S.A. Oblique photographs were taken during a series of low tide events, when the intertidal...

  20. Thermodynamic calculation and interatomic potential to predict the favored composition region for the Cu-Zr-Al metallic glass formation.

    PubMed

    Cui, Y Y; Wang, T L; Li, J H; Dai, Y; Liu, B X

    2011-03-01

    For the Cu-Zr-Al system, the glass forming compositions were firstly calculated based on the extended Miedema's model, suggesting that the amorphous phase could be thermodynamically favored over a large composition region. An n-body potential was then constructed under the smoothed and long-range second-moment-approximation of tight-binding formulism. Applying the constructed Cu-Zr-Al potential, molecular dynamics simulations were conducted using solid solution models to compare relative stability of crystalline solid solution versus its disordered counterpart. Simulations reveal that the physical origin of metallic glass formation is crystalline lattice collapsing while solute concentration exceeding the critical value, thus predicting a hexagonal composition region, within which the Cu-Zr-Al ternary metallic glass formation is energetically favored. The molecular dynamics simulations predicted composition region is defined as the quantitative glass-forming-ability or glass-forming-region of the Cu-Zr-Al system. PMID:21229150

  1. Multimodel predictive system for carbon dioxide solubility in saline formation waters.

    PubMed

    Wang, Zan; Small, Mitchell J; Karamalidis, Athanasios K

    2013-02-01

    The prediction of carbon dioxide solubility in brine at conditions relevant to carbon sequestration (i.e., high temperature, pressure, and salt concentration (T-P-X)) is crucial when this technology is applied. Eleven mathematical models for predicting CO(2) solubility in brine are compared and considered for inclusion in a multimodel predictive system. Model goodness of fit is evaluated over the temperature range 304-433 K, pressure range 74-500 bar, and salt concentration range 0-7 m (NaCl equivalent), using 173 published CO(2) solubility measurements, particularly selected for those conditions. The performance of each model is assessed using various statistical methods, including the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC). Different models emerge as best fits for different subranges of the input conditions. A classification tree is generated using machine learning methods to predict the best-performing model under different T-P-X subranges, allowing development of a multimodel predictive system (MMoPS) that selects and applies the model expected to yield the most accurate CO(2) solubility prediction. Statistical analysis of the MMoPS predictions, including a stratified 5-fold cross validation, shows that MMoPS outperforms each individual model and increases the overall accuracy of CO(2) solubility prediction across the range of T-P-X conditions likely to be encountered in carbon sequestration applications.

  2. Multimodel Predictive System for Carbon Dioxide Solubility in Saline Formation Waters

    SciTech Connect

    Wang, Zan; Small, Mitchell J; Karamalidis, Athanasios K

    2013-02-05

    The prediction of carbon dioxide solubility in brine at conditions relevant to carbon sequestration (i.e., high temperature, pressure, and salt concentration (T-P-X)) is crucial when this technology is applied. Eleven mathematical models for predicting CO{sub 2} solubility in brine are compared and considered for inclusion in a multimodel predictive system. Model goodness of fit is evaluated over the temperature range 304–433 K, pressure range 74–500 bar, and salt concentration range 0–7 m (NaCl equivalent), using 173 published CO{sub 2} solubility measurements, particularly selected for those conditions. The performance of each model is assessed using various statistical methods, including the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC). Different models emerge as best fits for different subranges of the input conditions. A classification tree is generated using machine learning methods to predict the best-performing model under different T-P-X subranges, allowing development of a multimodel predictive system (MMoPS) that selects and applies the model expected to yield the most accurate CO{sub 2} solubility prediction. Statistical analysis of the MMoPS predictions, including a stratified 5-fold cross validation, shows that MMoPS outperforms each individual model and increases the overall accuracy of CO{sub 2} solubility prediction across the range of T-P-X conditions likely to be encountered in carbon sequestration applications.

  3. Predicting standard-dose PET image from low-dose PET and multimodal MR images using mapping-based sparse representation

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Zhang, Pei; An, Le; Ma, Guangkai; Kang, Jiayin; Shi, Feng; Wu, Xi; Zhou, Jiliu; Lalush, David S.; Lin, Weili; Shen, Dinggang

    2016-01-01

    Positron emission tomography (PET) has been widely used in clinical diagnosis for diseases and disorders. To obtain high-quality PET images requires a standard-dose radionuclide (tracer) injection into the human body, which inevitably increases risk of radiation exposure. One possible solution to this problem is to predict the standard-dose PET image from its low-dose counterpart and its corresponding multimodal magnetic resonance (MR) images. Inspired by the success of patch-based sparse representation (SR) in super-resolution image reconstruction, we propose a mapping-based SR (m-SR) framework for standard-dose PET image prediction. Compared with the conventional patch-based SR, our method uses a mapping strategy to ensure that the sparse coefficients, estimated from the multimodal MR images and low-dose PET image, can be applied directly to the prediction of standard-dose PET image. As the mapping between multimodal MR images (or low-dose PET image) and standard-dose PET images can be particularly complex, one step of mapping is often insufficient. To this end, an incremental refinement framework is therefore proposed. Specifically, the predicted standard-dose PET image is further mapped to the target standard-dose PET image, and then the SR is performed again to predict a new standard-dose PET image. This procedure can be repeated for prediction refinement of the iterations. Also, a patch selection based dictionary construction method is further used to speed up the prediction process. The proposed method is validated on a human brain dataset. The experimental results show that our method can outperform benchmark methods in both qualitative and quantitative measures.

  4. Predicting standard-dose PET image from low-dose PET and multimodal MR images using mapping-based sparse representation.

    PubMed

    Wang, Yan; Zhang, Pei; An, Le; Ma, Guangkai; Kang, Jiayin; Shi, Feng; Wu, Xi; Zhou, Jiliu; Lalush, David S; Lin, Weili; Shen, Dinggang

    2016-01-21

    Positron emission tomography (PET) has been widely used in clinical diagnosis for diseases and disorders. To obtain high-quality PET images requires a standard-dose radionuclide (tracer) injection into the human body, which inevitably increases risk of radiation exposure. One possible solution to this problem is to predict the standard-dose PET image from its low-dose counterpart and its corresponding multimodal magnetic resonance (MR) images. Inspired by the success of patch-based sparse representation (SR) in super-resolution image reconstruction, we propose a mapping-based SR (m-SR) framework for standard-dose PET image prediction. Compared with the conventional patch-based SR, our method uses a mapping strategy to ensure that the sparse coefficients, estimated from the multimodal MR images and low-dose PET image, can be applied directly to the prediction of standard-dose PET image. As the mapping between multimodal MR images (or low-dose PET image) and standard-dose PET images can be particularly complex, one step of mapping is often insufficient. To this end, an incremental refinement framework is therefore proposed. Specifically, the predicted standard-dose PET image is further mapped to the target standard-dose PET image, and then the SR is performed again to predict a new standard-dose PET image. This procedure can be repeated for prediction refinement of the iterations. Also, a patch selection based dictionary construction method is further used to speed up the prediction process. The proposed method is validated on a human brain dataset. The experimental results show that our method can outperform benchmark methods in both qualitative and quantitative measures. PMID:26732849

  5. Cognitive Correlates of Map-Reading Ability.

    ERIC Educational Resources Information Center

    Sholl, M. Jeanne; Egeth, Howard E.

    1982-01-01

    When the mathematics and extended range vocabulary subtests on the Relief Format Assessment Test were factor analyzed, altitude estimation (predicted by mathematics aptitude) and terrain analysis (predicted by vocabulary skills) were found to underly map-reading performance. Solutions were found to be dependent on verbal-analytic ability more than…

  6. In vivo prediction of tuberculosis-associated cavity formation in rabbits.

    PubMed

    Luna, Brian; Kubler, André; Larsson, Christer; Foster, Brent; Bagci, Ulas; Mollura, Daniel J; Jain, Sanjay K; Bishai, William R

    2015-02-01

    The presence of cavitary lesions in patients with tuberculosis poses a significant clinical concern due to the risk of infectivity and the risk of antibiotic treatment failure. We describe 2 algorithms that use noninvasive positron emission tomography (PET) and computed tomography (CT) to predict the development of cavitary lesions in rabbits. Analysis of the PET region of interest predicted cavitary disease with 100% sensitivity and 76% specificity, and analysis of the CT region of interest predicted cavitary disease with 83.3% sensitivity and 76.9% specificity. Our results show that restricting our analysis to regions with high [(18)F]-fluorodeoxyglucose uptake provided the best combination of sensitivity and specificity.

  7. Preliminary geologic mapping of Cretaceous and Tertiary formations in the eastern part of the Little Snake River coal field, Carbon County, Wyoming

    USGS Publications Warehouse

    Haacke, Jon E.; Barclay, C. S. Venable; Hettinger, Robert D.

    2016-09-30

    In the 1970s and 1980s, C.S. Venable Barclay conducted geologic mapping of areas primarily underlain by Cretaceous coals in the eastern part of the Little Snake River coal field (LSR) in Carbon County, southwest Wyoming. With some exceptions, most of the mapping data were never published. Subsequently, after his retirement from the U.S. Geological Survey (USGS), his field maps and field notebooks were archived in the USGS Field Records. Due to a pending USGS coal assessment of the Little Snake River coal field area and planned geological mapping to be conducted by the Wyoming State Geological Survey, Barclay’s mapping data needed to be published to support these efforts. Subsequently, geologic maps were scanned and georeferenced into a geographic information system, and project and field notes were scanned into Portable Document Format (PDF) files. Data for seventeen 7½-minute quadrangles are presented in this report. This publication is solely intended to compile the mapping data as it was last worked on by Barclay and provides no interpretation or modification of his work.

  8. Is there more valuable information in PWI datasets for a voxel-wise acute ischemic stroke tissue outcome prediction than what is represented by typical perfusion maps?

    NASA Astrophysics Data System (ADS)

    Forkert, Nils Daniel; Siemonsen, Susanne; Dalski, Michael; Verleger, Tobias; Kemmling, Andre; Fiehler, Jens

    2014-03-01

    The acute ischemic stroke is a leading cause for death and disability in the industry nations. In case of a present acute ischemic stroke, the prediction of the future tissue outcome is of high interest for the clinicians as it can be used to support therapy decision making. Within this context, it has already been shown that the voxel-wise multi-parametric tissue outcome prediction leads to more promising results compared to single channel perfusion map thresholding. Most previously published multi-parametric predictions employ information from perfusion maps derived from perfusion-weighted MRI together with other image sequences such as diffusion-weighted MRI. However, it remains unclear if the typically calculated perfusion maps used for this purpose really include all valuable information from the PWI dataset for an optimal tissue outcome prediction. To investigate this problem in more detail, two different methods to predict tissue outcome using a k-nearest-neighbor approach were developed in this work and evaluated based on 18 datasets of acute stroke patients with known tissue outcome. The first method integrates apparent diffusion coefficient and perfusion parameter (Tmax, MTT, CBV, CBF) information for the voxel-wise prediction, while the second method employs also apparent diffusion coefficient information but the complete perfusion information in terms of the voxel-wise residue functions instead of the perfusion parameter maps for the voxel-wise prediction. Overall, the comparison of the results of the two prediction methods for the 18 patients using a leave-one-out cross validation revealed no considerable differences. Quantitatively, the parameter-based prediction of tissue outcome led to a mean Dice coefficient of 0.474, while the prediction using the residue functions led to a mean Dice coefficient of 0.461. Thus, it may be concluded from the results of this study that the perfusion parameter maps typically derived from PWI datasets include all

  9. Prebiotic Atmospheric Chemistry on Titan: Formation Kinetics via Ab Initio Calculations for Potential Energy Surface (PES) Mapping

    NASA Astrophysics Data System (ADS)

    Gonzalez, Dayana; Mebel, Alexander

    2016-03-01

    It has been recently shown that Titan provides a unique perspective in our solar system: its atmosphere is comparable to a model of prebiotic Earth's. Provided the organic cationic and anionic molecular species identified by the Cassini spacecraft, this research characterizes reaction pathways for the reactions of methyl derivatives of the cyclopropenyl cation, the methyl cation with methyl- and dimethyl-acetylene, and reactions of resonance structures of protonated acrylonitrile with CH2NH. Isomerization and dissociation reactions involving methyl-cyclopropenyl cations, the perinaphthenyl cation and anion, and cations of pyrimidine and purine precursors of nucleobases will be examined to locate reaction pathways, intermediates, transition states, and products of the reactions. Gaussian '09 software is used for ab initio calculations to map out the PES. Geometry optimizations and vibrational frequency computations are preformed via the double-hybrid density functional B2PLYP-D3. Single-point energies are refined by use of the explicitly-correlated coupled-cluster CCSD(T)-F12 method. Rate constants are calculated using microcanonical RRKM theory, and pressure effects evaluated used the Master Equation approach; these allow for prediction of absolute rate constants and product branching ratios at different pressures and temperatures.

  10. Potentiometric-surface map of water in the Lakota Formation and equivalent units in the northern Great Plains area of Montana

    USGS Publications Warehouse

    Levings, Gary Wayne

    1982-01-01

    The potentiometric surface of water in the lower Cretaceous Lakota Formation and equivalent units (Cut Bank Sandstone Member , Sunburst Sandstone Member, and Moulton Member of Kootenai formation; Third Cat Creek sandstone of Kootenai Formation; Pryor Conglomerate Member of Kootenai Formation) is shown on a base at a scale of 1:1,000,000. The map is one of a series produced as part of a regional study of aquifers of Cenozoic and Mesozoic age in the northern Great Plains of Montana. The contour interval is 200 feet. Water in the Lakota Formation and equivalent units occurs under water-table and artesian conditions. The direction of regional groundwater movement is east and north from the recharge areas in the Little Belt and Big Snowy Mountains. The average discharge from 20 wells is about 29 gallons per minute and the specific capacity of 18 wells averages 0.75 gallon per minute per foot of drawdown.

  11. High expression of MAP7 predicts adverse prognosis in young patients with cytogenetically normal acute myeloid leukemia

    PubMed Central

    Fu, Lin; Fu, Huaping; Zhou, Lei; Xu, Keman; Pang, Yifan; Hu, Kai; Wang, Jing; Tian, Lei; Liu, Yuanyuan; Wang, Jijun; Jing, Hongmei; Huang, Wenrong; Ke, Xiaoyan; Shi, Jinlong

    2016-01-01

    Microtubule-associated protein 7 (MAP7) plays an important role in cancer cells. In this study, we identified the prognostic significance of MAP7 expression in cytogenetically normal acute myeloid leukemia (CN-AML) patients (aged <60 years) based on several microarray datasets. In the first group (n = 129), high MAP7 expression (MAP7high) was associated with adverse overall survival (OS; P = 0.0441) and event-free survival (EFS; P = 0.0114) compared with low MAP7 expression (MAP7low). In addition, the prognostic significance of MAP7 was confirmed by European Leukemia Net (ELN) intermediate-I genetic categories and multivariable analysis. In the second independent group of CN-AML patients (aged <60 years), MAP7high was also associated with adverse OS (n = 88, OS; P = 0.00811). To understand the inherent mechanisms of MAP7’s prognosis, we investigated genome-wide gene/microRNA expression signatures associated with MAP7 expression. Several known oncogenic genes/microRNAs and anti-oncogenic genes/microRNAs were disordered in MAP7high CN-AML patients. In conclusion, MAP7high is an adverse prognostic biomarker for CN-AML, which may be attributed to the distinctive genome-wide gene/microRNA expression and related cell signaling pathways. PMID:27686215

  12. A comparative study on the predictive ability of the decision tree, support vector machine and neuro-fuzzy models in landslide susceptibility mapping using GIS

    NASA Astrophysics Data System (ADS)

    Pradhan, Biswajeet

    2013-02-01

    The purpose of the present study is to compare the prediction performances of three different approaches such as decision tree (DT), support vector machine (SVM) and adaptive neuro-fuzzy inference system (ANFIS) for landslide susceptibility mapping at Penang Hill area, Malaysia. The necessary input parameters for the landslide susceptibility assessments were obtained from various sources. At first, landslide locations were identified by aerial photographs and field surveys and a total of 113 landslide locations were constructed. The study area contains 340,608 pixels while total 8403 pixels include landslides. The landslide inventory was randomly partitioned into two subsets: (1) part 1 that contains 50% (4000 landslide grid cells) was used in the training phase of the models; (2) part 2 is a validation dataset 50% (4000 landslide grid cells) for validation of three models and to confirm its accuracy. The digitally processed images of input parameters were combined in GIS. Finally, landslide susceptibility maps were produced, and the performances were assessed and discussed. Total fifteen landslide susceptibility maps were produced using DT, SVM and ANFIS based models, and the resultant maps were validated using the landslide locations. Prediction performances of these maps were checked by receiver operating characteristics (ROC) by using both success rate curve and prediction rate curve. The validation results showed that, area under the ROC curve for the fifteen models produced using DT, SVM and ANFIS varied from 0.8204 to 0.9421 for success rate curve and 0.7580 to 0.8307 for prediction rate curves, respectively. Moreover, the prediction curves revealed that model 5 of DT has slightly higher prediction performance (83.07), whereas the success rate showed that model 5 of ANFIS has better prediction (94.21) capability among all models. The results of this study showed that landslide susceptibility mapping in the Penang Hill area using the three approaches (e

  13. Interface and Strain Energy Revolution Texture Map To Predict Structure and Optical Properties of Sputtered PbSe Thin Films.

    PubMed

    Sun, Xigui; Gao, Kewei; Pang, Xiaolu; Yang, Huisheng

    2016-01-13

    The preferred growth orientation of the sputtered lead selenide (PbSe) thin films on Si(100) substrates was thermodynamically simulated and calculated on the basis of the density functional theory. The results showed that the total free energy variation during the grain growth is dominated by the interface and strain energy minimization under certain conditions, indicating that the preferred growth orientation and related optical properties of the PbSe thin films can be effectively modified by these two energy variations. Thermodynamically, the PbSe[200] and PbSe[220] preferred orientations are obtained when the interface and strain energy minimization dominate the total free energy variation, respectively. A texture map related to the interface and strain energy revolution was obtained, which can be used to predict the structure and optical properties of the sputtered PbSe thin films, and its applicability was confirmed by the real X-ray diffraction and Fourier transform infrared spectroscopy experimental results of four midfrequency sputtered PbSe thin films with designed thickness and microstrain deposited on Si(100) substrates.

  14. A comparison of methods to predict solid phase heats of formation of molecular energetic salts.

    PubMed

    Byrd, Edward F C; Rice, Betsy M

    2009-01-01

    In this study a variety of methods were used to compute the energies for lattice enthalpies and gas phase heats of formation of the ionic constituents used in Born-Fajans-Haber cycles to produce solid phase heats of formation of molecular ionic energetic crystals. Several quantum mechanically based or empirical approaches to calculate either the heat of formation of the ionic constituents in the gas phase (deltaH(o)f(g)) or the lattice enthalpy (deltaH(o)Lattice) were evaluated. Solid phase heats of formation calculated from combinations of deltaH(o)f(g) and deltaH(o)Lattice determined through various approaches are compared with experimental values for a series of molecular energetic salts with 1:1, 2:1 and 2:2 charge ratios. Recommendations for combinations of deltaH(o)f(g) and deltaH(o)Lattice to produce best agreement with experiment are given, along with suggestions for improvements of the methods.

  15. On the integration of HydroProg and FloodMap: towards real-time inundation predictions in the upper Nysa Klodzka basin (SW Poland)

    NASA Astrophysics Data System (ADS)

    Yu, Dapeng; Mizinski, Bartlomiej; Latocha, Agnieszka; Parzoch, Krzysztof; Niedzielski, Tomasz

    2015-04-01

    The paper summarizes attempts to link the HydroProg system for issuing the real-time warnings against hydrologic hazards (research project no. 2011/01/D/ST10/04171 of the National Science Centre of Poland) with the hydrodynamic FloodMap model. HydroProg itself integrates hydrometeorological gauging networks with dissimilar hydrologic models in order to deliver multiple river stage prognoses and their multimodel ensemble prediction. FloodMap uses HydroProg-delivered forecasts and, along with data on topography and bed profiles, produces short-term (3-hour) prognoses of inundation. The research is carried out in five test sites located in the upper Nysa Klodzka basin (SW Poland), where the HydroProg-Klodzko prototype is experimentally implemented, and is steadily providing the users with experimental prognoses of river stages (www.klodzko.hydroprog.uni.wroc.pl). The successful implementation of HydroProg in Klodzko County is due to the partnership with its authorities who developed and maintain the Local System for Flood Monitoring (Lokalny System Oslony Przeciwpowodziowej - LSOP). For the purpose of HydroProg-FloodMap integration we selected: (1) three hydrograph prediction approaches offered by HydroProg-Klodzko, (2) five specific peak flow events, and (3) five test sites along four mountainous rivers of the study area, focusing on 3-hour hydrograph predictions. The calibration of the FloodMap model is based on an overbank flow reconstruction, produced as a result of mapping geomorphological consequences of the flood that occurred in the Zelazno site on 26-28 June 2009. The discussion as to whether the calibrated model can be extrapolated and used in the remaining test sites is also provided. By utilizing FloodMap with observed water depth data we produce simulated inundation, which we verify against the orthophoto images acquired by the Unmanned Aerial Vehicle (UAV). Subsequently, we again run the FloodMap model with the HydroProg-delivered prognoses of

  16. Suitability of Organic Matter Surrogates to Predict Trihalomethane Formation in Drinking Water Sources

    PubMed Central

    Pifer, Ashley D.; Fairey, Julian L.

    2014-01-01

    Abstract Broadly applicable disinfection by-product (DBP) precursor surrogate parameters could be leveraged at drinking water treatment plants (DWTPs) to curb formation of regulated DBPs, such as trihalomethanes (THMs). In this study, dissolved organic carbon (DOC), ultraviolet absorbance at 254 nm (UV254), fluorescence excitation/emission wavelength pairs (IEx/Em), and the maximum fluorescence intensities (FMAX) of components from parallel factor (PARAFAC) analysis were evaluated as total THM formation potential (TTHMFP) precursor surrogate parameters. A diverse set of source waters from eleven DWTPs located within watersheds underlain by six different soil orders were coagulated with alum at pH 6, 7, and 8, resulting in 44 sample waters. DOC, UV254, IEx/Em, and FMAX values were measured to characterize dissolved organic matter in raw and treated waters and THMs were quantified following formation potential tests with free chlorine. For the 44 sample waters, the linear TTHMFP correlation with UV254 was stronger (r2=0.89) than I240/562 (r2=0.81, the strongest surrogate parameter from excitation/emission matrix pair picking), FMAX from a humic/fulvic acid-like PARAFAC component (r2=0.78), and DOC (r2=0.75). Results indicate that UV254 was the most accurate TTHMFP precursor surrogate parameter assessed for a diverse group of raw and alum-coagulated waters. PMID:24669183

  17. Kinetic Study to Predict Sigma Phase Formation in Duplex Stainless Steels

    NASA Astrophysics Data System (ADS)

    dos Santos, Daniella Caluscio; Magnabosco, Rodrigo

    2016-04-01

    This work presents an improved kinetic study of sigma phase formation during isothermal aging between 973 K and 1223 K (700 °C and 950 °C), based on Kolmogorov-Johnson-Mehl-Avrami (K-J-M-A) model, established from volume fraction of sigma phase determined in backscattered electron images over polished surfaces of aged samples. The kinetic study shows a change in the main mechanism of sigma formation between 973 K and 1173 K (700 °C and 900 °C), from a nucleation-governed stage to a diffusion-controlled growth-coarsening stage, confirmed by a double inclination in K-J-M-A plots and microstructural observations. A single inclination in K-J-M-A plots was observed for the 1223 K (950 °C) aging temperature, showing that kinetic behavior in this temperature is only related to diffusion-controlled growth of sigma phase. The estimated activation energies for the nucleation of sigma phase are close to the molybdenum diffusion in ferrite, probably the controlling mechanism of sigma phase nucleation. The proposed time-temperature-transformation (TTT) diagram shows a "double c curve" configuration, probably associated to the presence of chi-phase formed between 973 K and 1073 K (700 °C and 800 °C), which acts as heterogeneous nuclei for sigma phase formation in low aging temperatures.

  18. Computer prediction of peptide maps: assignment of polypeptides to human and mouse mitochondrial DNA genes by analysis of two-dimensional-proteolytic digest gels.

    PubMed

    Wallace, D C; Yang, J H; Ye, J H; Lott, M T; Oliver, N A; McCarthy, J

    1986-04-01

    We have prepared a computer program that predicts complete and partial peptide maps from amino acid sequences. The program fragments amino acid sequences at designated cleavage sites and calculates the molecular weight and relative labeling of each peptide. These data are graphed as log molecular weight of the original protein (X-axis) vs. log molecular weight of the component peptides (Y-axis). The program is interactive, permitting adjustment of a number of graphic parameters and alteration of the position of proteins in the first dimension to accommodate aberrations in protein mobility. The program has been used to predict the V8 protease peptide maps of the 13 open reading frames (ORFs) identified in the human and the mouse mitochondrial DNA (mtDNA) sequences. The results were compared to the V8 protease peptide maps obtained for mouse and human mitochondrially synthesized proteins by two-dimensional proteolytic digest gels. A high correlation was observed between the predicted and observed peptide maps. These results suggest the assignment of several proteins to mtDNA genes.

  19. Assessing Changes in High School Students' Conceptual Understanding through Concept Maps before and after the Computer-Based Predict-Observe-Explain (CB-POE) Tasks on Acid-Base Chemistry at the Secondary Level

    ERIC Educational Resources Information Center

    Yaman, Fatma; Ayas, Alipasa

    2015-01-01

    Although concept maps have been used as alternative assessment methods in education, there has been an ongoing debate on how to evaluate students' concept maps. This study discusses how to evaluate students' concept maps as an assessment tool before and after 15 computer-based Predict-Observe-Explain (CB-POE) tasks related to acid-base chemistry.…

  20. Random forests for feature selection in QSPR Models - an application for predicting standard enthalpy of formation of hydrocarbons

    PubMed Central

    2013-01-01

    Background One of the main topics in the development of quantitative structure-property relationship (QSPR) predictive models is the identification of the subset of variables that represent the structure of a molecule and which are predictors for a given property. There are several automated feature selection methods, ranging from backward, forward or stepwise procedures, to further elaborated methodologies such as evolutionary programming. The problem lies in selecting the minimum subset of descriptors that can predict a certain property with a good performance, computationally efficient and in a more robust way, since the presence of irrelevant or redundant features can cause poor generalization capacity. In this paper an alternative selection method, based on Random Forests to determine the variable importance is proposed in the context of QSPR regression problems, with an application to a manually curated dataset for predicting standard enthalpy of formation. The subsequent predictive models are trained with support vector machines introducing the variables sequentially from a ranked list based on the variable importance. Results The model generalizes well even with a high dimensional dataset and in the presence of highly correlated variables. The feature selection step was shown to yield lower prediction errors with RMSE values 23% lower than without feature selection, albeit using only 6% of the total number of variables (89 from the original 1485). The proposed approach further compared favourably with other feature selection methods and dimension reduction of the feature space. The predictive model was selected using a 10-fold cross validation procedure and, after selection, it was validated with an independent set to assess its performance when applied to new data and the results were similar to the ones obtained for the training set, supporting the robustness of the proposed approach. Conclusions The proposed methodology seemingly improves the prediction

  1. Use of a Routh-Russel deformation map to achieve film formation of a latex with a high glass transition temperature.

    PubMed

    Gonzalez, Edurne; Paulis, María; Barandiaran, María Jesús; Keddie, Joseph L

    2013-02-12

    In the film formation of latex, particle deformation can occur by processes of wet sintering, dry sintering, or capillary action. When latex films dry nonuniformly and when particles deform and coalesce while the film is still wet, a detrimental skin layer will develop at the film surface. In their process model, Routh and Russel proposed that the operative particle deformation mechanism can be determined by the values of control parameters on a deformation map. Here, the film formation processes of three methyl methacrylate/butyl acrylate copolymer latexes with high glass transition temperatures (T(g)), ranging from 45 to 64 °C, have been studied when heated by infrared radiation. Adjusting the infrared (IR) power density enables the film temperature, polymer viscosity, and evaporation rate during latex film formation to be controlled precisely. Different polymer particle deformation mechanisms have been demonstrated for the same latex under a variety of film formation process conditions. When the temperature is too high, a skin layer develops. On the other hand, when the temperature is too low, particles deform by dry sintering, and the process requires extended time periods. The deduced mechanisms can be interpreted and explained by the Routh-Russel deformation maps. Film formation of hard (high T(g)) coatings is achieved without using coalescing aids that emit volatile organic compounds (VOCs), which is a significant technical achievement.

  2. Validation of a mapping and prediction model for human fasciolosis transmission in Andean very high altitude endemic areas using remote sensing data.

    PubMed

    Fuentes, M V; Malone, J B; Mas-Coma, S

    2001-04-27

    The present paper aims to validate the usefulness of the Normalized Difference Vegetation Index (NDVI) obtained by satellite remote sensing for the development of local maps of risk and for prediction of human fasciolosis in the Northern Bolivian Altiplano. The endemic area, which is located at very high altitudes (3800-4100 m) between Lake Titicaca and the valley of the city of La Paz, presents the highest prevalences and intensities of fasciolosis known in humans. NDVI images of 1.1 km resolution from the Advanced Very High Resolution Radiometer (AVHRR) sensor on board the National Oceanic and Atmospheric Administration (NOAA) series of environmental satellites appear to provide adequate information for a study area such as that of the Northern Bolivian Altiplano. The predictive value of the remotely sensed map based on NDVI data appears to be better than that from forecast indices based only on climatic data. A close correspondence was observed between real ranges of human fasciolosis prevalence at 13 localities of known prevalence rates and the predicted ranges of fasciolosis prevalence using NDVI maps. However, results based on NDVI map data predicted zones as risk areas where, in fact, field studies have demonstrated the absence of lymnaeid populations during snail surveys, corroborated by the absence of the parasite in humans and livestock. NDVI data maps represent a useful data component in long-term efforts to develop a comprehensive geographical information system control program model that accurately fits real epidemiological and transmission situations of human fasciolosis in high altitude endemic areas in Andean countries.

  3. Predictive mapping of soil organic carbon in wet cultivated lands using classification-tree based models: the case study of Denmark.

    PubMed

    Bou Kheir, Rania; Greve, Mogens H; Bøcher, Peder K; Greve, Mette B; Larsen, René; McCloy, Keith

    2010-05-01

    Soil organic carbon (SOC) is one of the most important carbon stocks globally and has large potential to affect global climate. Distribution patterns of SOC in Denmark constitute a nation-wide baseline for studies on soil carbon changes (with respect to Kyoto protocol). This paper predicts and maps the geographic distribution of SOC across Denmark using remote sensing (RS), geographic information systems (GISs) and decision-tree modeling (un-pruned and pruned classification trees). Seventeen parameters, i.e. parent material, soil type, landscape type, elevation, slope gradient, slope aspect, mean curvature, plan curvature, profile curvature, flow accumulation, specific catchment area, tangent slope, tangent curvature, steady-state wetness index, Normalized Difference Vegetation Index (NDVI), Normalized Difference Wetness Index (NDWI) and Soil Color Index (SCI) were generated to statistically explain SOC field measurements in the area of interest (Denmark). A large number of tree-based classification models (588) were developed using (i) all of the parameters, (ii) all Digital Elevation Model (DEM) parameters only, (iii) the primary DEM parameters only, (iv), the remote sensing (RS) indices only, (v) selected pairs of parameters, (vi) soil type, parent material and landscape type only, and (vii) the parameters having a high impact on SOC distribution in built pruned trees. The best constructed classification tree models (in the number of three) with the lowest misclassification error (ME) and the lowest number of nodes (N) as well are: (i) the tree (T1) combining all of the parameters (ME=29.5%; N=54); (ii) the tree (T2) based on the parent material, soil type and landscape type (ME=31.5%; N=14); and (iii) the tree (T3) constructed using parent material, soil type, landscape type, elevation, tangent slope and SCI (ME=30%; N=39). The produced SOC maps at 1:50,000 cartographic scale using these trees are highly matching with coincidence values equal to 90.5% (Map T1

  4. Advancing predictive models for particulate formation in turbulent flames via massively parallel direct numerical simulations

    PubMed Central

    Bisetti, Fabrizio; Attili, Antonio; Pitsch, Heinz

    2014-01-01

    Combustion of fossil fuels is likely to continue for the near future due to the growing trends in energy consumption worldwide. The increase in efficiency and the reduction of pollutant emissions from combustion devices are pivotal to achieving meaningful levels of carbon abatement as part of the ongoing climate change efforts. Computational fluid dynamics featuring adequate combustion models will play an increasingly important role in the design of more efficient and cleaner industrial burners, internal combustion engines, and combustors for stationary power generation and aircraft propulsion. Today, turbulent combustion modelling is hindered severely by the lack of data that are accurate and sufficiently complete to assess and remedy model deficiencies effectively. In particular, the formation of pollutants is a complex, nonlinear and multi-scale process characterized by the interaction of molecular and turbulent mixing with a multitude of chemical reactions with disparate time scales. The use of direct numerical simulation (DNS) featuring a state of the art description of the underlying chemistry and physical processes has contributed greatly to combustion model development in recent years. In this paper, the analysis of the intricate evolution of soot formation in turbulent flames demonstrates how DNS databases are used to illuminate relevant physico-chemical mechanisms and to identify modelling needs. PMID:25024412

  5. Advancing predictive models for particulate formation in turbulent flames via massively parallel direct numerical simulations.

    PubMed

    Bisetti, Fabrizio; Attili, Antonio; Pitsch, Heinz

    2014-08-13

    Combustion of fossil fuels is likely to continue for the near future due to the growing trends in energy consumption worldwide. The increase in efficiency and the reduction of pollutant emissions from combustion devices are pivotal to achieving meaningful levels of carbon abatement as part of the ongoing climate change efforts. Computational fluid dynamics featuring adequate combustion models will play an increasingly important role in the design of more efficient and cleaner industrial burners, internal combustion engines, and combustors for stationary power generation and aircraft propulsion. Today, turbulent combustion modelling is hindered severely by the lack of data that are accurate and sufficiently complete to assess and remedy model deficiencies effectively. In particular, the formation of pollutants is a complex, nonlinear and multi-scale process characterized by the interaction of molecular and turbulent mixing with a multitude of chemical reactions with disparate time scales. The use of direct numerical simulation (DNS) featuring a state of the art description of the underlying chemistry and physical processes has contributed greatly to combustion model development in recent years. In this paper, the analysis of the intricate evolution of soot formation in turbulent flames demonstrates how DNS databases are used to illuminate relevant physico-chemical mechanisms and to identify modelling needs.

  6. Advancing predictive models for particulate formation in turbulent flames via massively parallel direct numerical simulations.

    PubMed

    Bisetti, Fabrizio; Attili, Antonio; Pitsch, Heinz

    2014-08-13

    Combustion of fossil fuels is likely to continue for the near future due to the growing trends in energy consumption worldwide. The increase in efficiency and the reduction of pollutant emissions from combustion devices are pivotal to achieving meaningful levels of carbon abatement as part of the ongoing climate change efforts. Computational fluid dynamics featuring adequate combustion models will play an increasingly important role in the design of more efficient and cleaner industrial burners, internal combustion engines, and combustors for stationary power generation and aircraft propulsion. Today, turbulent combustion modelling is hindered severely by the lack of data that are accurate and sufficiently complete to assess and remedy model deficiencies effectively. In particular, the formation of pollutants is a complex, nonlinear and multi-scale process characterized by the interaction of molecular and turbulent mixing with a multitude of chemical reactions with disparate time scales. The use of direct numerical simulation (DNS) featuring a state of the art description of the underlying chemistry and physical processes has contributed greatly to combustion model development in recent years. In this paper, the analysis of the intricate evolution of soot formation in turbulent flames demonstrates how DNS databases are used to illuminate relevant physico-chemical mechanisms and to identify modelling needs. PMID:25024412

  7. The SAMI Galaxy Survey: can we trust aperture corrections to predict star formation?

    NASA Astrophysics Data System (ADS)

    Richards, S. N.; Bryant, J. J.; Croom, S. M.; Hopkins, A. M.; Schaefer, A. L.; Bland-Hawthorn, J.; Allen, J. T.; Brough, S.; Cecil, G.; Cortese, L.; Fogarty, L. M. R.; Gunawardhana, M. L. P.; Goodwin, M.; Green, A. W.; Ho, I.-T.; Kewley, L. J.; Konstantopoulos, I. S.; Lawrence, J. S.; Lorente, N. P. F.; Medling, A. M.; Owers, M. S.; Sharp, R.; Sweet, S. M.; Taylor, E. N.

    2016-01-01

    In the low-redshift Universe (z < 0.3), our view of galaxy evolution is primarily based on fibre optic spectroscopy surveys. Elaborate methods have been developed to address aperture effects when fixed aperture sizes only probe the inner regions for galaxies of ever decreasing redshift or increasing physical size. These aperture corrections rely on assumptions about the physical properties of galaxies. The adequacy of these aperture corrections can be tested with integral-field spectroscopic data. We use integral-field spectra drawn from 1212 galaxies observed as part of the SAMI Galaxy Survey to investigate the validity of two aperture correction methods that attempt to estimate a galaxy's total instantaneous star formation rate. We show that biases arise when assuming that instantaneous star formation is traced by broad-band imaging, and when the aperture correction is built only from spectra of the nuclear region of galaxies. These biases may be significant depending on the selection criteria of a survey sample. Understanding the sensitivities of these aperture corrections is essential for correct handling of systematic errors in galaxy evolution studies.

  8. The EMPIRE Survey: Systematic Variations in the Dense Gas Fraction and Star Formation Efficiency from Full-disk Mapping of M51

    NASA Astrophysics Data System (ADS)

    Bigiel, Frank; Leroy, Adam K.; Jiménez-Donaire, Maria J.; Pety, Jérôme; Usero, Antonio; Cormier, Diane; Bolatto, Alberto; Garcia-Burillo, Santiago; Colombo, Dario; González-García, Manuel; Hughes, Annie; Kepley, Amanda A.; Kramer, Carsten; Sandstrom, Karin; Schinnerer, Eva; Schruba, Andreas; Schuster, Karl; Tomicic, Neven; Zschaechner, Laura

    2016-05-01

    We present the first results from the EMPIRE survey, an IRAM large program that is mapping tracers of high-density molecular gas across the disks of nine nearby star-forming galaxies. Here, we present new maps of the 3 mm transitions of HCN, HCO+, and HNC across the whole disk of our pilot target, M51. As expected, dense gas correlates with tracers of recent star formation, filling the “luminosity gap” between Galactic cores and whole galaxies. In detail, we show that both the fraction of gas that is dense, {f}{dense} traced by HCN/CO, and the rate at which dense gas forms stars, {{SFE}}{dense} traced by IR/HCN, depend on environment in the galaxy. The sense of the dependence is that high-surface-density, high molecular gas fraction regions of the galaxy show high dense gas fractions and low dense gas star formation efficiencies. This agrees with recent results for individual pointings by Usero et al. but using unbiased whole-galaxy maps. It also agrees qualitatively with the behavior observed contrasting our own Solar Neighborhood with the central regions of the Milky Way. The sense of the trends can be explained if the dense gas fraction tracks interstellar pressure but star formation occurs only in regions of high density contrast.

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

    PubMed Central

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

    2012-01-01

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

  10. The 'partial resonance' of the ring in the NLO crystal melaminium formate: study using vibrational spectra, DFT, HOMO-LUMO and MESP mapping.

    PubMed

    Binoy, J; Marchewka, M K; Jayakumar, V S

    2013-03-01

    The molecular geometry and vibrational spectral investigations of melaminium formate, a potential material known for toxicity and NLO activity, has been performed. The FT IR and FT Raman spectral investigations of melaminium formate is performed aided by the computed spectra of melaminium formate, triazine, melamine, melaminium and formate ion, along with bond orders and PED, computed using the density functional method (B3LYP) with 6-31G(d) basis set and XRD data, to reveal intermolecular interactions of amino groups with neighbor formula units in the crystal, intramolecular H⋯H repulsion of amino group hydrogen with protonating hydrogen, consequent loss of resonance in the melaminium ring, restriction of resonance to N(3)C(1)N(1) moiety leading to special type resonance of the ring and the resonance structure of CO(2) group of formate ion. The 3D matrix of hyperpolarizability tensor components has been computed to quantify NLO activity of melamine, melaminium and melaminium formate and the hyperpolarizability enhancement is analyzed using computed plots of HOMO and LUMO orbitals. A new mechanism of proton transfer responsible for NLO activity has been suggested, based on anomalous IR spectral bands in the high wavenumber region. The computed MEP contour maps have been used to analyze the interaction of melaminium and formate ions in the crystal.

  11. Deleterious Phase Formation in Next- Generation Nickel-Base Superalloys Predicted

    NASA Technical Reports Server (NTRS)

    Ritzert, Frank J.

    1999-01-01

    Nickel- (Ni-) base superalloy single crystals represent the state-of-the-art for turbine engine airfoil applications because they offer the best balance of properties under the high operating temperatures required for efficient engine operation. Current trends in alloy design take advantage of improved creep rupture strength with the addition of higher levels of refractory elements. In particular, the addition of significantly higher levels of rhenium in third-generation superalloys is key for both microstructural stability and creep rupture strength. Although refractories provide strength benefits, alloys tend to be unstable when their refractory content is high because of topologically close-packed (TCP) phases. The formation of these phases in sufficient amount is detrimental to the performance of these alloys because of their brittle nature and because they deplete the Nirich matrix of potent solid-solution strengthening elements.

  12. The Formation of Massive Stars by Collisional Mergers: Theoretical Constraints and Observational Predictions

    NASA Astrophysics Data System (ADS)

    Zinnecker, Hans; Bally, John

    2004-08-01

    While accretional growth can lead to the formation of massive stars in isolation or in loose OB associations, collisional growth and mergers can only occur in high-density cluster environments. We will discuss the conditions in a very dense young star cluster under which the merger scenario of massive star formation may work, and whether these conditions are likely to occur somewhere in the our Galaxy (Orion BN/KL, NGC 3603, W3-IRS5), the Local Group (30 Dor, NGC 604), or other galaxies (NGC 5253, Henize 2-10, The Antennae clusters). We explore the observational consequences of the merger scenario. Protostellar mergers may produce high luminosity infrared flares. Mergers may be surrounded by thick tori of expanding debris, impulsive wide-angle outflows, shock-induced maser and radio continuum emission. The collision products are expected to have fast stellar rotation and a large multiplicity fraction. Massive stars growing by a series of mergers may produce eruptive bursts of wide-angle outflow activity with random orientations; the walls of the resulting outflow cavities may be observable as filaments of dense gas and dust pointing away from the massive star. The extremely rare merger of two stars close to the upper mass limit of the IMF may be a possible pathway to hypernova-generated gamma-ray bursters. We also speculate that the outflow "fingers" from the OMC1 core in the Orion molecular cloud were produced by a merger less than a thousand years ago (Bally and Zinnecker 2004, AJ submitted). Mergers may not occur in every dense young cluster, but certainly in some of them, especially those where dynamical mass segregation of massive stars has taken place (Freitag and Benz 2004, astro-ph 0403621).

  13. The earliest phases of high-mass star formation: a 3 square degree millimeter continuum mapping of Cygnus X

    NASA Astrophysics Data System (ADS)

    Motte, F.; Bontemps, S.; Schilke, P.; Schneider, N.; Menten, K. M.; Broguière, D.

    2007-12-01

    Aims:Our current knowledge of high-mass star formation is mainly based on follow-up studies of bright sources found by IRAS, and is thus biased against its earliest phases, inconspicuous at infrared wavelengths. We therefore started searching, in an unbiased way and in the closest high-mass star-forming complexes, for the high-mass analogs of low-mass pre-stellar cores and class 0 protostars. Methods: We have made an extensive 1.2 mm continuum mosaicing study of the Cygnus X molecular cloud complex using the MAMBO cameras at the IRAM 30 m telescope. The ˜ 3°2 imaged areas cover all the high-column density (AV ≥ 15 mag) clouds of this nearby (~1.7 kpc) cloud complex actively forming OB stars. We then compared our millimeter maps with mid-infrared images, and have made SiO(2-1) follow-up observations of the best candidate progenitors of high-mass stars. Results: Our complete study of Cygnus X with ~0.09 pc resolution provides, for the first time, an unbiased census of massive young stellar objects. We discover 129 massive dense cores (FWHM size ~0.1 pc, M1.2~mm = 4-950 M_⊙, volume-averaged density ~105 cm-3), among which ~42 are probable precursors of high-mass stars. A large fraction of the Cygnus X dense cores (2/3 of the sample) remain undetected by the MSX satellite, regardless of the mass range considered. Among the most massive (≥40 M_⊙) cores, infrared-quiet objects are driving powerful outflows traced by SiO emission. Our study qualifies 17 cores as good candidates for hosting massive infrared-quiet protostars, while up to 25 cores potentially host high-luminosity infrared protostars. We fail to discover the high-mass analogs of pre-stellar dense cores (~0.1 pc, > 104 cm-3) in Cygnus X, but find several massive starless clumps (~ 0.8 pc, 7 × 103 cm-3) that might be gravitationally bound. Conclusions: Since our sample is derived from a single molecular complex and covers every embedded phase of high-mass star formation, it gives the first

  14. Thermodynamics of Micelle Formation: Prediction of Micelle Size and Size Distribution

    PubMed Central

    Tanford, Charles

    1974-01-01

    This paper presents a simple theory for the calculation of micelle size and other properties of micelleforming systems. The theory is based on the separate estimation of the components of the free energy arising from hydrophobic attraction and from head group repulsion, each as a function of micelle size. The difficult problem of an a priori calculation of the repulsive factor is circumvented by using experimental values of this parameter, derived from pressure-area curves of monolayers at an interface between an aqueous solution and liquid hydrocarbon. Though some parameters of the theory are still somewhat uncertain, self-consistent and physically realistic values can be assigned that lead to almost exact prediction of experimental micelle sizes and critical micelle concentrations for two distinctly different ionic detergents. PMID:4525294

  15. Underground Excavation Behaviour of the Queenston Formation: Tunnel Back Analysis for Application to Shaft Damage Dimension Prediction

    NASA Astrophysics Data System (ADS)

    Perras, Matthew A.; Wannenmacher, Helmut; Diederichs, Mark S.

    2015-07-01

    The Niagara Tunnel Project (NTP) is a 10.1 km long water-diversion tunnel in Niagara Falls, Ontario, which was excavated by a 7.2 m radius tunnel boring machine. Approximately half the tunnel length was excavated through the Queenston Formation, which locally is a shale to mudstone. Typical overbreak depths ranged between 2 and 4 m with a maximum of 6 m observed. Three modelling approaches were used to back analyse the brittle failure process at the NTP: damage initiation and spalling limit, laminated anisotropy modelling, and ubiquitous joint approaches. Analyses were conducted for three tunnel chainages: 3 + 000, 3 + 250, and 3 + 500 m because the overbreak depth increased from 2 to 4 m. All approaches produced similar geometries to those measured. The laminated anisotropy modelling approach was able to produced chord closures closest to those measured, using a joint normal to shear stiffness ratio between 1 and 2. This understanding was applied to a shaft excavation model in the Queenston Formation at the proposed Deep Geological Repository (DGR) site for low and intermediate level nuclear waste storage in Canada. The maximum damage depth was 1.9 m; with an average of 1.0 m. Important differences are discussed between the tunnel and shaft orientation with respect to bedding. The models show that the observed normalized depth of failure at the NTP would over-predict the depth of damage expected in the Queenston Formation at the DGR.

  16. A kinetic study on the potential of a hybrid reaction mechanism for prediction of NOx formation in biomass grate furnaces

    NASA Astrophysics Data System (ADS)

    Zahirović, Selma; Scharler, Robert; Kilpinen, Pia; Obernberger, Ingwald

    2011-10-01

    This paper presents the verification of a hybrid reaction mechanism (28 species, 104 reactions) by means of a kinetic study with a view to its application for the CFD-based prediction of gas phase combustion and NOx formation in biomass grate furnaces. The mechanism is based on a skeletal kinetic scheme that includes the subsets for H2, CO, NH3 and HCN oxidation derived from the detailed Kilpinen 97 reaction mechanism. To account for the CH4 breakdown two related reactions from the 4-step global mechanism for hydrocarbons oxidation by Jones and Lindstedt were adopted. The hybrid mechanism was compared to the global mechanism and validated against the detailed Kilpinen 97 mechanism. For that purpose plug flow reactor simulations at conditions relevant to biomass combustion (atmospheric pressure, 1200-1600 K) for approximations of the flue gases in a grate furnace at fuel lean and fuel rich conditions were carried out. The hybrid reaction mechanism outperformed the global one at all conditions investigated. The most striking differences obtained in predictions by the hybrid and the detailed mechanism at the residence times prior to ignition were attributed to the simplified description of the CH4 oxidation in the case of the former. The overall agreement regarding both combustion and NOx chemistry between the hybrid and the detailed mechanism was better at fuel lean conditions than at fuel rich conditions. However, also at fuel rich conditions, the agreement was improving with increasing temperature. Moreover, it was shown that an improvement in the prediction of NOx formation by the N-subset of the hybrid reaction mechanism can be achieved by replacing its C-H-O subset with that of the detailed one.

  17. On a report that the 2012 M 6.0 earthquake in Italy was predicted after seeing an unusual cloud formation

    USGS Publications Warehouse

    Thomas, J.N.; Masci, F; Love, Jeffrey J.

    2015-01-01

    Several recently published reports have suggested that semi-stationary linear-cloud formations might be causally precursory to earthquakes. We examine the report of Guangmeng and Jie (2013), who claim to have predicted the 2012 M 6.0 earthquake in the Po Valley of northern Italy after seeing a satellite photograph (a digital image) showing a linear-cloud formation over the eastern Apennine Mountains of central Italy. From inspection of 4 years of satellite images we find numerous examples of linear-cloud formations over Italy. A simple test shows no obvious statistical relationship between the occurrence of these cloud formations and earthquakes that occurred in and around Italy. All of the linear-cloud formations we have identified in satellite images, including that which Guangmeng and Jie (2013) claim to have used to predict the 2012 earthquake, appear to be orographic – formed by the interaction of moisture-laden wind flowing over mountains. Guangmeng and Jie (2013) have not clearly stated how linear-cloud formations can be used to predict the size, location, and time of an earthquake, and they have not published an account of all of their predictions (including any unsuccessful predictions). We are skeptical of the validity of the claim by Guangmeng and Jie (2013) that they have managed to predict any earthquakes.

  18. Use of HμREL Human Coculture System for Prediction of Intrinsic Clearance and Metabolite Formation for Slowly Metabolized Compounds.

    PubMed

    Hultman, Ia; Vedin, Charlotta; Abrahamsson, Anna; Winiwarter, Susanne; Darnell, Malin

    2016-08-01

    Design of slowly metabolized compounds is an important goal in many drug discovery projects. Standard hepatocyte suspension intrinsic clearance (CLint) methods can only provide reliable CLint values above 2.5 μL/min/million cells. A method that permits extended incubation time with maintained performance and metabolic activity of the in vitro system is warranted to allow in vivo clearance predictions and metabolite identification of slowly metabolized drugs. The aim of this study was to evaluate the static HμREL coculture of human hepatocytes with stromal cells to be set up in-house as a standard method for in vivo clearance prediction and metabolite identification of slowly metabolized drugs. Fourteen low CLint compounds were incubated for 3 days, and seven intermediate to high CLint compounds and a cocktail of cytochrome P450 (P450) marker substrates were incubated for 3 h. In vivo clearance was predicted for 20 compounds applying the regression line approach, and HμREL coculture predicted the human intrinsic clearance for 45% of the drugs within 2-fold and 70% of the drugs within 3-fold of the clinical values. CLint values as low as 0.3 μL/min/million hepatocytes were robustly produced, giving 8-fold improved sensitivity of robust low CLint determination, over the cutoff in hepatocyte suspension CLint methods. The CLint values of intermediate to high CLint compounds were at similar levels both in HμREL coculture and in freshly thawed hepatocytes. In the HμREL coculture formation rates for five P450-isoform marker reactions, paracetamol (CYP1A2), 1-OH-bupropion (CYP2B6), 4-OH-diclofenac (CYP2C9), and 1-OH-midazolam (3A4) were within the range of literature values for freshly thawed hepatocytes, whereas 1-OH-bufuralol (CYP2D6) formation rate was lower. Further, both phase I and phase II metabolites were detected and an increased number of metabolites were observed in the HμREL coculture compared to hepatocyte suspension. In conclusion, HμREL coculture can

  19. Predicting Tropical Cyclogenesis with a Global Mesoscale Model: Hierarchical Multiscale Interactions During the Formation of Tropical Cyclone Nargis(2008)

    NASA Technical Reports Server (NTRS)

    Shen, B.-W.; Tao, W.-K.; Lau, W. K.; Atlas, R.

    2010-01-01

    Very severe cyclonic storm Nargis devastated Burma (Myanmar) in May 2008, caused tremendous damage and numerous fatalities, and became one of the 10 deadliest tropical cyclones (TCs) of all time. To increase the warning time in order to save lives and reduce economic damage, it is important to extend the lead time in the prediction of TCs like Nargis. As recent advances in high-resolution global models and supercomputing technology have shown the potential for improving TC track and intensity forecasts, the ability of a global mesoscale model to predict TC genesis in the Indian Ocean is examined in this study with the aim of improving simulations of TC climate. High-resolution global simulations with real data show that the initial formation and intensity variations of TC Nargis can be realistically predicted up to 5 days in advance. Preliminary analysis suggests that improved representations of the following environmental conditions and their hierarchical multiscale interactions were the key to achieving this lead time: (1) a westerly wind burst and equatorial trough, (2) an enhanced monsoon circulation with a zero wind shear line, (3) good upper-level outflow with anti-cyclonic wind shear between 200 and 850 hPa, and (4) low-level moisture convergence.

  20. Stresses and fractures in the Frontier Formation, Green River Basin, predicted from basin-margin tectonic element interactions

    SciTech Connect

    Lorenz, J.C.

    1996-01-01

    Natural fractures and in situ stresses commonly dictate subsurface reservoir permeability and permeability anisotropy, as well as the effectiveness of stimulation techniques in low-permeability, natural gas reservoirs. This paper offers an initial prediction for the orientations of the fracture and stress systems in the tight gas reservoirs of the Frontier Formation, in the Green River basin of southwestern Wyoming. It builds on a previous report that addressed fractures and stresses in the western part of the basin and on ideas developed for the rest of the basin, using the principle that thrust faults are capable of affecting the stress magnitudes and orientations in little-deformed strata several hundreds of kilometers in front of a thrust. The prediction of subsurface stresses and natural fracture orientations is an undertaking that requires the willingness to revise models as definitive data are acquired during drilling. The predictions made in this paper are offered with the caveat that geology in the subsurface is always full of surprises.

  1. On vegetation mapping in Alaska using LANDSAT imagery with primary concerns for method and purpose in satellite image-based vegetation and land-use mapping and the visual interpretation of imagery in photographic format

    NASA Technical Reports Server (NTRS)

    Anderson, J. H. (Principal Investigator)

    1976-01-01

    The author has identified the following significant results. A simulated color infrared LANDSAT image covering the western Seward Peninsula was used for identifying and mapping vegetation by direct visual examination. The 1:1,083,400 scale print used was prepared by a color additive process using positive transparencies from MSS bands 4, 5, and 7. Seven color classes were recognized. A vegetation map of 3200 sq km area just west of Fairbanks, Alaska was made. Five colors were recognized on the image and identified to vegetation types roughly equivalent to formations in the UNESCO classification: orange - broadleaf deciduous forest; gray - needleleaf evergreen forest; light violet - subarctic alpine tundra vegetation; violet - broadleaf deciduous shrub thicket; and dull violet - bog vegetation.

  2. Microbial regulation of terrestrial nitrous oxide formation: understanding the biological pathways for prediction of emission rates.

    PubMed

    Hu, Hang-Wei; Chen, Deli; He, Ji-Zheng

    2015-09-01

    The continuous increase of the greenhouse gas nitrous oxide (N2O) in the atmosphere due to increasing anthropogenic nitrogen input in agriculture has become a global concern. In recent years, identification of the microbial assemblages responsible for soil N2O production has substantially advanced with the development of molecular technologies and the discoveries of novel functional guilds and new types of metabolism. However, few practical tools are available to effectively reduce in situ soil N2O flux. Combating the negative impacts of increasing N2O fluxes poses considerable challenges and will be ineffective without successfully incorporating microbially regulated N2O processes into ecosystem modeling and mitigation strategies. Here, we synthesize the latest knowledge of (i) the key microbial pathways regulating N2O production and consumption processes in terrestrial ecosystems and the critical environmental factors influencing their occurrence, and (ii) the relative contributions of major biological pathways to soil N2O emissions by analyzing available natural isotopic signatures of N2O and by using stable isotope enrichment and inhibition techniques. We argue that it is urgently necessary to incorporate microbial traits into biogeochemical ecosystem modeling in order to increase the estimation reliability of N2O emissions. We further propose a molecular methodology oriented framework from gene to ecosystem scales for more robust prediction and mitigation of future N2O emissions. PMID:25934121

  3. Effects of the number of markers per haplotype and clustering of haplotypes on the accuracy of QTL mapping and prediction of genomic breeding values.

    PubMed

    Calus, Mario P L; Meuwissen, Theo H E; Windig, Jack J; Knol, Egbert F; Schrooten, Chris; Vereijken, Addie L J; Veerkamp, Roel F

    2009-01-15

    The aim of this paper was to compare the effect of haplotype definition on the precision of QTL-mapping and on the accuracy of predicted genomic breeding values. In a multiple QTL model using identity-by-descent (IBD) probabilities between haplotypes, various haplotype definitions were tested i.e. including 2, 6, 12 or 20 marker alleles and clustering base haplotypes related with an IBD probability of > 0.55, 0.75 or 0.95. Simulated data contained 1100 animals with known genotypes and phenotypes and 1000 animals with known genotypes and unknown phenotypes. Genomes comprising 3 Morgan were simulated and contained 74 polymorphic QTL and 383 polymorphic SNP markers with an average r2 value of 0.14 between adjacent markers. The total number of haplotypes decreased up to 50% when the window size was increased from two to 20 markers and decreased by at least 50% when haplotypes related with an IBD probability of > 0.55 instead of > 0.95 were clustered. An intermediate window size led to more precise QTL mapping. Window size and clustering had a limited effect on the accuracy of predicted total breeding values, ranging from 0.79 to 0.81. Our conclusion is that different optimal window sizes should be used in QTL-mapping versus genome-wide breeding value prediction.

  4. Detailed geologic field mapping and radiometric dating of the Abanico Formation in the Principal Cordillera, central Chile: Evidence of protracted volcanism and implications for Cenozoic tectonics

    NASA Astrophysics Data System (ADS)

    Mosolf, J.; Gans, P. B.; Wyss, A. R.; Cottle, J. M.

    2011-12-01

    Many aspects of the long-term evolution of intra-arc processes remain poorly understood, including temporal trends in magmatism, temporal and spatial patterns of volcanism, and styles of arc deformation. The Abanico Formation in the Principal Cordillera of central Chile is a thick, well-exposed section of volcanogenic strata providing a superb locale for the investigation of continental arc dynamics over a 60+ myr timescale. In this study, eight new litho-stratigraphic members of the Abanico Formation are described and mapped in the Río Tinguiririca river area. Mapping and field observations show the Abanico Formation measures up to ~2.5 km in composite stratigraphic thickness. The lower ~1.1 km of the section (> 46 Ma) is dominated by andesitic breccias interbedded with andesite, basaltic andesite, and olivine basalt lavas. The upper 1.4 km of the section (< 46 Ma) consists of volcaniclastic sandstone interbedded with abundant dacitic tuffs and minor andesite, basaltic andesite, and basalt flows. Nineteen new LA-MC-ICPMS U-Pb zircon ages and ten new 40Ar/39Ar whole rock and plagioclase ages obtained for the Abanico Formation clarify ambiguous field relationships and provide a robust chrono-stratigraphic framework spanning ~72 to 11 Ma; these new ages significantly revise the maximum mid-Tertiary age for the Abanico Formation previously established by the mammal fossil record. The map units are cut by numerous dacitic to gabbroic dikes and sills with ages spanning the Eocene to Pliocene. The Abanico Formation is overlain in angular unconformity by Pliocene and Quaternary volcanics composed mainly of andesite, basaltic andesite, and basalt lavas. A strong deformational overprint has tilted, folded, and faulted the Abanico map units. Fold axes and reverse faults, both east and west directed, are generally N-S trending. Reverse faults achieve up to ~50 Ma of stratigraphic separation, placing Campanian strata on Miocene rocks with up to ~2 km of vertical throw. The

  5. Sequential star formation in the Sh 254-258 molecular cloud: HHT maps of CO J=3-2 and 2-1 emission

    NASA Astrophysics Data System (ADS)

    Bieging, J. H.; Peters, W. L.; Vilaro, B. Vila; Schlottman, K.; Kulesa, C.

    We present large area maps of CO and ^13CO J=2-1 and CO J=3-2 emission for the molecular clouds associated with the small group of Sharpless H II regions, Sh 254-258. The maps were made with the University of Arizona Heinrich Hertz Telescope (HHT) and have an angular resolution of 33 arcsec over a 0.75 x 1 deg field in the 2-1 lines and 24 arcsec over two 10 x 10 arcmin fields in the 3-2 line. The maps have full sensitivity over all angular scales down to the resolution limit, and reveal a ridge of warm molecular gas near the H II regions, and an extended cloud of low brightness much larger in size than the warm ridge. We use a statistical equilibrium analysis of the CO lines to derive cloud properties for various locations in the maps. We compare the cloud properties and morphology with the H II regions (traced in optical and radio continuum images) and warm dust/PAH emission (traced in MSX images). The H II regions have evidently shaped, compressed, and heated the molecular cloud. We present a scenario for a sequence of ongoing B-star formation in the cloud, possibly induced by the dynamical effects of expanding H II regions.

  6. Atlas Based Segmentation and Mapping of Organs at Risk from Planning CT for the Development of Voxel-Wise Predictive Models of Toxicity in Prostate Radiotherapy

    NASA Astrophysics Data System (ADS)

    Acosta, Oscar; Dowling, Jason; Cazoulat, Guillaume; Simon, Antoine; Salvado, Olivier; de Crevoisier, Renaud; Haigron, Pascal

    The prediction of toxicity is crucial to managing prostate cancer radiotherapy (RT). This prediction is classically organ wise and based on the dose volume histograms (DVH) computed during the planning step, and using for example the mathematical Lyman Normal Tissue Complication Probability (NTCP) model. However, these models lack spatial accuracy, do not take into account deformations and may be inappropiate to explain toxicity events related with the distribution of the delivered dose. Producing voxel wise statistical models of toxicity might help to explain the risks linked to the dose spatial distribution but is challenging due to the difficulties lying on the mapping of organs and dose in a common template. In this paper we investigate the use of atlas based methods to perform the non-rigid mapping and segmentation of the individuals' organs at risk (OAR) from CT scans. To build a labeled atlas, 19 CT scans were selected from a population of patients treated for prostate cancer by radiotherapy. The prostate and the OAR (Rectum, Bladder, Bones) were then manually delineated by an expert and constituted the training data. After a number of affine and non rigid registration iterations, an average image (template) representing the whole population was obtained. The amount of consensus between labels was used to generate probabilistic maps for each organ. We validated the accuracy of the approach by segmenting the organs using the training data in a leave one out scheme. The agreement between the volumes after deformable registration and the manually segmented organs was on average above 60% for the organs at risk. The proposed methodology provides a way to map the organs from a whole population on a single template and sets the stage to perform further voxel wise analysis. With this method new and accurate predictive models of toxicity will be built.

  7. Correlation between the compact regions predicted by the average distance map (ADM) and the biologically active sites in atrial natriuretic peptide.

    PubMed

    Kikuchi, T

    1992-10-01

    The prediction of the short-range compact regions of human atrial natriuretic peptide (alpha-hANP), one of the biologically active peptides, has been made by means of the Average Distance Map(ADM). We found out that the location of the predicted short-range compact regions is consistent with the structural units determined by the NMR analysis (Kobayashi et al., 1988). Furthermore, the short-range compact regions correspond well to the biologically active areas of atriopeptin (103-125)-amide (which is homologous peptide to alpha-hANP), detected by the glycine substitution technique (Konishi et al., 1987). The results suggest that a predicted short-range compact region can be regarded as a possible active site in a biologically active peptide.

  8. New model of retinocollicular mapping predicts the mechanisms of axonal competition and explains the role of reverse molecular signaling during development.

    PubMed Central

    Grimbert, François; Cang, Jianhua

    2012-01-01

    Precise connections in the brain result from elaborate processes during development. In the visual system, axonal projections from retinal ganglion cells (RGCs) onto the superior colliculus (SC) form a precise retinotopic map. Studies have revealed that the development of retinocollicular maps involves three main factors: graded expression of molecular guidance cues such as EphAs and ephrin-As, activity-dependent processes driven by spontaneous activity in RGCs, and different forms of axonal competition. In this study, we develop a new, versatile model including these factors. We first model the selective arborization of RGC axons, mediated by EphA/ephrin-A signaling, without assuming that this initial process instructs the map's final topology. We also derive an integro-differential equation modeling a second, dynamic phase where activity-dependent plasticity of axonal arbors combined with their competition for collicular resources can deeply remodel the topology of immature maps. Our model hence challenges the view that retinotopic maps are instructed by matching molecular gradients and then merely refined by activity-dependent processes. We reproduce fine features of retinototopic map development in wild type and various transgenic mice, allowing a new understanding of the underlying mechanisms. Our model predicts that competition is not based on comparisons of axonal EphA receptor levels, but rather relies on the optimization of collicular resources mediated by neurotrophic receptors such as p75NTR. Our model finally clarifies the elusive role of reverse signaling between retinal ephrin-As and collicular EphAs by reproducing for the first time the phenotypes of two mouse genotypes where this function is altered. PMID:22787061

  9. Studies on the tempo of bubble formation in recently cavitated vessels: a model to predict the pressure of air bubbles.

    PubMed

    Wang, Yujie; Pan, Ruihua; Tyree, Melvin T

    2015-06-01

    A cavitation event in a vessel replaces water with a mixture of water vapor and air. A quantitative theory is presented to argue that the tempo of filling of vessels with air has two phases: a fast process that extracts air from stem tissue adjacent to the cavitated vessels (less than 10 s) and a slow phase that extracts air from the atmosphere outside the stem (more than 10 h). A model was designed to estimate how water tension (T) near recently cavitated vessels causes bubbles in embolized vessels to expand or contract as T increases or decreases, respectively. The model also predicts that the hydraulic conductivity of a stem will increase as bubbles collapse. The pressure of air bubbles trapped in vessels of a stem can be predicted from the model based on fitting curves of hydraulic conductivity versus T. The model was validated using data from six stem segments each of Acer mono and the clonal hybrid Populus 84 K (Populus alba × Populus glandulosa). The model was fitted to results with root mean square error less than 3%. The model provided new insight into the study of embolism formation in stem tissue and helped quantify the bubble pressure immediately after the fast process referred to above.

  10. Mapping geomorphic process domains to predict hillslope sediment size distribution using remotely-sensed data and field sampling, Inyo Creek, California

    NASA Astrophysics Data System (ADS)

    Leclere, S.; Sklar, L. S.; Genetti, J. R.

    2014-12-01

    The size distribution of sediments produced on hillslopes and supplied to channels depends on the geomorphic processes that weather, detach and transport rock fragments down slopes. Little in the way of theory or data is available to predict patterns in hillslope size distributions at the catchment scale from topographic and geologic maps. Here we use aerial imagery and a variety of remote sensing techniques to map and categorize geomorphic landscape units (GLUs) by inferred sediment production process regime, across the steep mountain catchment of Inyo Creek, eastern Sierra Nevada, California. We also use field measurements of particle size and local geomorphic attributes to test and refine GLU determinations. Across the 2 km of relief in this catchment, landcover varies from bare bedrock cliffs at higher elevations to vegetated, regolith-covered convex slopes at lower elevations. Hillslope gradient could provide a simple index of sediment production process, from rock spallation and landsliding at highest slopes, to tree-throw and other disturbance-driven soil production processes at lowest slopes. However, many other attributes are needed for a more robust predictive model, including elevation, curvature, aspect, drainage area, and color. We combine tools from ArcGIS, ERDAS Imagine and Envi with groundtruthing field work to find an optimal combination of attributes for defining sediment production GLUs. Key challenges include distinguishing: weathered from freshly eroded bedrock, boulders from intact bedrock, and landslide deposits from talus slopes. We take advantage of emerging technologies that provide new ways of conducting fieldwork and comparing field data to mapping solutions. In particular, cellphone GPS is approaching the accuracy of dedicated GPS systems and the ability to geo-reference photos simplifies field notes and increases accuracy of later map creation. However, the predictive power of the GLU mapping approach is limited by inherent uncertainty

  11. Genomic variation by whole-genome SNP mapping arrays predicts time-to-event outcome in patients with chronic lymphocytic leukemia: a comparison of CLL and HapMap genotypes.

    PubMed

    Schweighofer, Carmen D; Coombes, Kevin R; Majewski, Tadeusz; Barron, Lynn L; Lerner, Susan; Sargent, Rachel L; O'Brien, Susan; Ferrajoli, Alessandra; Wierda, William G; Czerniak, Bogdan A; Medeiros, L Jeffrey; Keating, Michael J; Abruzzo, Lynne V

    2013-03-01

    Genomic abnormalities, such as deletions in 11q22 or 17p13, are associated with poorer prognosis in patients with chronic lymphocytic leukemia (CLL). We hypothesized that unknown regions of copy number variation (CNV) affect clinical outcome and can be detected by array-based single-nucleotide polymorphism (SNP) genotyping. We compared SNP genotypes from 168 untreated patients with CLL with genotypes from 73 white HapMap controls. We identified 322 regions of recurrent CNV, 82 of which occurred significantly more often in CLL than in HapMap (CLL-specific CNV), including regions typically aberrant in CLL: deletions in 6q21, 11q22, 13q14, and 17p13 and trisomy 12. In univariate analyses, 35 of total and 11 of CLL-specific CNVs were associated with unfavorable time-to-event outcomes, including gains or losses in chromosomes 2p, 4p, 4q, 6p, 6q, 7q, 11p, 11q, and 17p. In multivariate analyses, six CNVs (ie, CLL-specific variations in 11p15.1-15.4 or 6q27) predicted time-to-treatment or overall survival independently of established markers of prognosis. Moreover, genotypic complexity (ie, the number of independent CNVs per patient) significantly predicted prognosis, with a median time-to-treatment of 64 months versus 23 months in patients with zero to one versus two or more CNVs, respectively (P = 3.3 × 10(-8)). In summary, a comparison of SNP genotypes from patients with CLL with HapMap controls allowed us to identify known and unknown recurrent CNVs and to determine regions and rates of CNV that predict poorer prognosis in patients with CLL.

  12. Mapping the spatial distribution of star formation in cluster galaxies at z ~0.5 with the Grism Lens-Amplified Survey from Space (GLASS)

    NASA Astrophysics Data System (ADS)

    Vulcani, B.; Treu, T.; Schmidt, K. B.; Poggianti, B. M.; Dressler, A.; Fontana, A.; Bradač, M.; Brammer, G. B.; Hoag, A.; Huang, K.; Malkan, M.; Pentericci, L.; Trenti, M.; von der Linden, A.; Abramson, L.; He, J.; Morris, G.

    2016-06-01

    What physical processes regulate star formation in dense environments? Understanding why galaxy evolution is environment dependent is one of the key questions of current astrophysics. I will present the first characterization of the spatial distribution of star formation in cluster galaxies at z~0.5, and compare to a field control sample, in order to quantify the role of different physical processes that are believed to be responsible for shutting down star formation (Vulcani et al. 2015, Vulcani et al. in prep). The analysis makes use of data from the Grism Lens-Amplified Survey from Space (GLASS), a large HST cycle-21 program targeting 10 massive galaxy clusters with extensive HST imaging from CLASH and the Frontier Field Initiative. The program consists of 140 primary and 140 parallel orbits of near-infrared WCF3 and optical ACS slitless grism observations, which result in 3D spectroscopy of hundreds of galaxies. The grism data are used to produce spatially resolved maps of the star formation density, while the stellar mass density and optical surface brightness are obtained from multiband imaging. I will describe quantitative measures of the spatial location and extent of the star formation rate. I will show that both in clusters and in the field, Hα is more extended than the rest-frame UV continuum in 60% of the cases, consistent with diffuse star formation and inside out growth. The Hα emission appears more extended in cluster galaxies than in the field, pointing perhaps to ionized gas being stripped and/or star formation being enhanced at large radii. The peak of the Hα emission and that of the continuum are offset by less than 1 kpc. I will also correlate the properties of the Hα maps to the cluster global properties, such as the hot gas density, and the surface mass density. The characterization of the spatial distribution of Halpha provides a new window, yet poorly exploited, on the mechanisms that regulate star formation and morphological

  13. Lyman-α emitters in the context of hierarchical galaxy formation: predictions for VLT/MUSE surveys

    NASA Astrophysics Data System (ADS)

    Garel, T.; Guiderdoni, B.; Blaizot, J.

    2016-02-01

    The VLT/Multi Unit Spectrograph Explorer (MUSE) integral-field spectrograph can detect Lyα emitters (LAE) in the redshift range 2.8 ≲ z ≲ 6.7 in a homogeneous way. Ongoing MUSE surveys will notably probe faint Lyα sources that are usually missed by current narrow-band surveys. We provide quantitative predictions for a typical wedding-cake observing strategy with MUSE based on mock catalogues generated with a semi-analytic model of galaxy formation coupled to numerical Lyα radiation transfer models in gas outflows. We expect ≈1500 bright LAEs (FLyα ≳ 10-17 erg s-1 cm-2) in a typical shallow field (SF) survey carried over ≈100 arcmin2 , and ≈2000 sources as faint as 10-18 erg s-1 cm-2 in a medium-deep field (MDF) survey over 10 arcmin2 . In a typical deep field (DF) survey of 1 arcmin2 , we predict that ≈500 extremely faint LAEs (FLyα ≳ 4 × 10-19 erg s-1 cm-2) will be found. Our results suggest that faint Lyα sources contribute significantly to the cosmic Lyα luminosity and SFR budget. While the host haloes of bright LAEs at z ≈ 3 and 6 have descendants with median masses of 2 × 1012 and 5 × 1013 M⊙, respectively, the faintest sources detectable by MUSE at these redshifts are predicted to reside in haloes which evolve into typical sub-L* and L* galaxy haloes at z = 0. We expect typical DF and MDF surveys to uncover the building blocks of Milky Way-like objects, even probing the bulk of the stellar mass content of LAEs located in their progenitor haloes at z ≈ 3.

  14. Mapping the spatial patterns of field traffic and traffic intensity to predict soil compaction risks at the field scale

    NASA Astrophysics Data System (ADS)

    Duttmann, Rainer; Kuhwald, Michael; Nolde, Michael

    2015-04-01

    Soil compaction is one of the main threats to cropland soils in present days. In contrast to easily visible phenomena of soil degradation, soil compaction, however, is obscured by other signals such as reduced crop yield, delayed crop growth, and the ponding of water, which makes it difficult to recognize and locate areas impacted by soil compaction directly. Although it is known that trafficking intensity is a key factor for soil compaction, until today only modest work has been concerned with the mapping of the spatially distributed patterns of field traffic and with the visual representation of the loads and pressures applied by farm traffic within single fields. A promising method for for spatial detection and mapping of soil compaction risks of individual fields is to process dGPS data, collected from vehicle-mounted GPS receivers and to compare the soil stress induced by farm machinery to the load bearing capacity derived from given soil map data. The application of position-based machinery data enables the mapping of vehicle movements over time as well as the assessment of trafficking intensity. It also facilitates the calculation of the trafficked area and the modeling of the loads and pressures applied to soil by individual vehicles. This paper focuses on the modeling and mapping of the spatial patterns of traffic intensity in silage maize fields during harvest, considering the spatio-temporal changes in wheel load and ground contact pressure along the loading sections. In addition to scenarios calculated for varying mechanical soil strengths, an example for visualizing the three-dimensional stress propagation inside the soil will be given, using the Visualization Toolkit (VTK) to construct 2D or 3D maps supporting to decision making due to sustainable field traffic management.

  15. Predicting Formation Damage in Aquifer Thermal Energy Storage Systems Utilizing a Coupled Hydraulic-Thermal-Chemical Reservoir Model

    NASA Astrophysics Data System (ADS)

    Müller, Daniel; Regenspurg, Simona; Milsch, Harald; Blöcher, Guido; Kranz, Stefan; Saadat, Ali

    2014-05-01

    In aquifer thermal energy storage (ATES) systems, large amounts of energy can be stored by injecting hot water into deep or intermediate aquifers. In a seasonal production-injection cycle, water is circulated through a system comprising the porous aquifer, a production well, a heat exchanger and an injection well. This process involves large temperature and pressure differences, which shift chemical equilibria and introduce or amplify mechanical processes. Rock-fluid interaction such as dissolution and precipitation or migration and deposition of fine particles will affect the hydraulic properties of the porous medium and may lead to irreversible formation damage. In consequence, these processes determine the long-term performance of the ATES system and need to be predicted to ensure the reliability of the system. However, high temperature and pressure gradients and dynamic feedback cycles pose challenges on predicting the influence of the relevant processes. Within this study, a reservoir model comprising a coupled hydraulic-thermal-chemical simulation was developed based on an ATES demonstration project located in the city of Berlin, Germany. The structural model was created with Petrel, based on data available from seismic cross-sections and wellbores. The reservoir simulation was realized by combining the capabilities of multiple simulation tools. For the reactive transport model, COMSOL Multiphysics (hydraulic-thermal) and PHREEQC (chemical) were combined using the novel interface COMSOL_PHREEQC, developed by Wissmeier & Barry (2011). It provides a MATLAB-based coupling interface between both programs. Compared to using COMSOL's built-in reactive transport simulator, PHREEQC additionally calculates adsorption and reaction kinetics and allows the selection of different activity coefficient models in the database. The presented simulation tool will be able to predict the most important aspects of hydraulic, thermal and chemical transport processes relevant to

  16. Mapping Atomic Orbitals with the Transmission Electron Microscope: Images of Defective Graphene Predicted from First-Principles Theory.

    PubMed

    Pardini, Lorenzo; Löffler, Stefan; Biddau, Giulio; Hambach, Ralf; Kaiser, Ute; Draxl, Claudia; Schattschneider, Peter

    2016-07-15

    Transmission electron microscopy has been a promising candidate for mapping atomic orbitals for a long time. Here, we explore its capabilities by a first-principles approach. For the example of defected graphene, exhibiting either an isolated vacancy or a substitutional nitrogen atom, we show that three different kinds of images are to be expected, depending on the orbital character. To judge the feasibility of visualizing orbitals in a real microscope, the effect of the optics' aberrations is simulated. We demonstrate that, by making use of energy filtering, it should indeed be possible to map atomic orbitals in a state-of-the-art transmission electron microscope. PMID:27472127

  17. USING LANDSCAPE ECOLOGY AND PARTIAL LEAST SQUARES PREDICTIONS TO MAP WATERSHEDS THAT ARE VULNERABLE TO NON-POINT SOURCE POLLUTION

    EPA Science Inventory

    The U.S. Environmental Protection Agency's Office of Research and Development have mapped and interpreted landscape-scale (i.e., broad scale) ecological metrics among watersheds in the upper White River watershed, producing the first geospatial models of water quality vulnerabili...

  18. Wavelets, self-organizing maps and artificial neural nets for predicting energy use and estimating uncertainties in energy savings in commercial buildings

    NASA Astrophysics Data System (ADS)

    Lei, Yafeng

    This dissertation develops a "neighborhood" based neural network model utilizing wavelet analysis and Self-organizing Map (SOM) to predict building baseline energy use. Wavelet analysis was used for feature extraction of the daily weather profiles. The resulting few significant wavelet coefficients represent not only average but also variation of the weather components. A SOM is used for clustering and projecting high-dimensional data into usually a one or two dimensional map to reveal the data structure which is not clear by visual inspection. In this study, neighborhoods that contain days with similar meteorological conditions are classified by a SOM using significant wavelet coefficients; a baseline model is then developed for each neighborhood. In each neighborhood, modeling is more robust without unnecessary compromises that occur in global predictor regression models. This method was applied to the Energy Predictor Shootout II dataset and compared with the winning entries for hourly energy use predictions. A comparison between the "neighborhood" based linear regression model and the change-point model for daily energy use prediction was also performed. We also studied the application of the non-parametric nearest neighborhood points approach in determining the uncertainty of energy use prediction. The uncertainty from "local" system behavior rather than from global statistical indices such as root mean square error and other measures is shown to be more realistic and credible than the statistical approaches currently used. In general, a baseline model developed by local system behavior is more reliable than a global baseline model. The "neighborhood" based neural network model was found to predict building baseline energy use more accurately and achieve more reliable estimation of energy savings as well as the associated uncertainties in energy savings from building retrofits.

  19. Genomic Variation by Whole-Genome SNP Mapping Arrays Predicts Time-to-Event Outcome in Patients with Chronic Lymphocytic Leukemia

    PubMed Central

    Schweighofer, Carmen D.; Coombes, Kevin R.; Majewski, Tadeusz; Barron, Lynn L.; Lerner, Susan; Sargent, Rachel L.; O'Brien, Susan; Ferrajoli, Alessandra; Wierda, William G.; Czerniak, Bogdan A.; Medeiros, L. Jeffrey; Keating, Michael J.; Abruzzo, Lynne V.

    2013-01-01

    Genomic abnormalities, such as deletions in 11q22 or 17p13, are associated with poorer prognosis in patients with chronic lymphocytic leukemia (CLL). We hypothesized that unknown regions of copy number variation (CNV) affect clinical outcome and can be detected by array-based single-nucleotide polymorphism (SNP) genotyping. We compared SNP genotypes from 168 untreated patients with CLL with genotypes from 73 white HapMap controls. We identified 322 regions of recurrent CNV, 82 of which occurred significantly more often in CLL than in HapMap (CLL-specific CNV), including regions typically aberrant in CLL: deletions in 6q21, 11q22, 13q14, and 17p13 and trisomy 12. In univariate analyses, 35 of total and 11 of CLL-specific CNVs were associated with unfavorable time-to-event outcomes, including gains or losses in chromosomes 2p, 4p, 4q, 6p, 6q, 7q, 11p, 11q, and 17p. In multivariate analyses, six CNVs (ie, CLL-specific variations in 11p15.1-15.4 or 6q27) predicted time-to-treatment or overall survival independently of established markers of prognosis. Moreover, genotypic complexity (ie, the number of independent CNVs per patient) significantly predicted prognosis, with a median time-to-treatment of 64 months versus 23 months in patients with zero to one versus two or more CNVs, respectively (P = 3.3 × 10−8). In summary, a comparison of SNP genotypes from patients with CLL with HapMap controls allowed us to identify known and unknown recurrent CNVs and to determine regions and rates of CNV that predict poorer prognosis in patients with CLL. PMID:23273604

  20. Vortex formation time-to-left ventricular early rapid filling relation: model-based prediction with echocardiographic validation.

    PubMed

    Ghosh, Erina; Shmuylovich, Leonid; Kovács, Sándor J

    2010-12-01

    During early rapid filling, blood aspirated by the left ventricle (LV) generates an asymmetric toroidal vortex whose development has been quantified using vortex formation time (VFT), a dimensionless index defined by the length-to-diameter ratio of the aspirated (equivalent cylindrical) fluid column. Since LV wall motion generates the atrioventricular pressure gradient resulting in the early transmitral flow (Doppler E-wave) and associated vortex formation, we hypothesized that the causal relation between VFT and diastolic function (DF), parametrized by stiffness, relaxation, and load, can be elucidated via kinematic modeling. Gharib et al. (Gharib M, Rambod E, Kheradvar A, Sahn DJ, Dabiri JO. Proc Natl Acad Sci USA 103: 6305-6308, 2006) approximated E-wave shape as a triangle and calculated VFT(Gharib) as triangle (E-wave) area (cm) divided by peak (Doppler M-mode derived) mitral orifice diameter (cm). We used a validated kinematic model of filling for the E-wave as a function of time, parametrized by stiffness, viscoelasticity, and load. To calculate VFT(kinematic), we computed the curvilinear E-wave area (using the kinematic model) and divided it by peak effective orifice diameter. The derived VFT-to-LV early rapid filling relation predicts VFT to be a function of peak E-wave-to-peak mitral annular tissue velocity (Doppler E'-wave) ratio as (E/E')(3/2). Validation utilized 262 cardiac cycles of simultaneous echocardiographic high-fidelity hemodynamic data from 12 subjects. VFT(Gharib) and VFT(kinematic) were calculated for each subject and were well-correlated (R(2) = 0.66). In accordance with prediction, VFT(kinematic) to (E/E')(3/2) relationship was validated (R(2) = 0.63). We conclude that VFT(kinematic) is a DF index computable in terms of global kinematic filling parameters of stiffness, viscoelasticity, and load. Validation of the fluid mechanics-to-chamber kinematics relation unites previously unassociated DF assessment methods and elucidates the

  1. Development of a predictive model for porosity distribution in the Smackover Formation of southwest Alabama. Final report, 1983-1984

    SciTech Connect

    Benson, J.

    1984-11-15

    The Upper Jurassic Smackover Formation is the major hydrocarbon producer in the State of Alabama having produced over 69.5 million bbls of oil, 63 million bbls of condensate, and 237 million Mcf of gas since the initial Smackover discovery from Toxey Field, Choctaw County in 1967. Smackover hydrocarbon exploration is hampered in Alabama and throughout the Gulf Coast by the inability to effectively predict porosity distribution in the unit. This report represents the results of the first year of a study designed to develop a predictive model for porosity distribution in the Smackover of southwestern Alabama. This study is based on analysis of over 900 thin-sections from 70 wells in southwest Alabama. Eight lithofacies were recognized in the Smackover in the study area. These are: anhydritic mudstone, microcrystalline dolomite, oolitic grainstone, skeletal-peloidal grainstone/packstone, algal boundstone, finely-crystalline dolomite, coarsely-crystalline dolomite, and mudstone. Depositional porosity in the Smackover ranged from very high in the oolitic grainstone lithologies to very low in the mudstone lithologies. This depositional porosity, however, has been significantly modified by diagenesis. Smackover sediments have undergone a complex history of diagenetic modification which has included micritization, multi-stage cementation, multi-stage dissolution, dolomitization, and sulfate mineralization. These diagenetic processes have occluded primary porosity and, in some cases, produced secondary porosity in lithologies which lacked primary porosity. Four primary pore types have been recognized in the Smackover; primary interparticulate, oomoldic, dolomitic intercrystalline, and vuggy. The occurrence of these pore types indicates porosity distribution is controlled by paleotopography which significantly influenced depositional and diagenetic processes. 20 references, 14 figures.

  2. Molecular Control of TiO2-NPs Toxicity Formation at Predicted Environmental Relevant Concentrations by Mn-SODs Proteins

    PubMed Central

    Wu, Qiuli; Li, Yiping; Tang, Meng; Ye, Boping; Wang, Dayong

    2012-01-01

    With growing concerns of the safety of nanotechnology, the in vivo toxicity of nanoparticles (NPs) at environmental relevant concentrations has drawn increasing attentions. We investigated the possible molecular mechanisms of titanium nanoparticles (Ti-NPs) in the induction of toxicity at predicted environmental relevant concentrations. In nematodes, small sizes (4 nm and 10 nm) of TiO2-NPs induced more severe toxicities than large sizes (60 nm and 90 nm) of TiO2-NPs on animals using lethality, growth, reproduction, locomotion behavior, intestinal autofluorescence, and reactive oxygen species (ROS) production as endpoints. Locomotion behaviors could be significantly decreased by exposure to 4-nm and 10-nm TiO2-NPs at concentration of 1 ng/L in nematodes. Among genes required for the control of oxidative stress, only the expression patterns of sod-2 and sod-3 genes encoding Mn-SODs in animals exposed to small sizes of TiO2-NPs were significantly different from those in animals exposed to large sizes of TiO2-NPs. sod-2 and sod-3 gene expressions were closely correlated with lethality, growth, reproduction, locomotion behavior, intestinal autofluorescence, and ROS production in TiO2-NPs-exposed animals. Ectopically expression of human and nematode Mn-SODs genes effectively prevented the induction of ROS production and the development of toxicity of TiO2-NPs. Therefore, the altered expression patterns of Mn-SODs may explain the toxicity formation for different sizes of TiO2-NPs at predicted environmental relevant concentrations. In addition, we demonstrated here a strategy to investigate the toxicological effects of exposure to NPs upon humans by generating transgenic strains in nematodes for specific human genes. PMID:22973466

  3. A predictive penetrative fracture mapping method from regional potential field and geologic datasets, southwest Colorado Plateau, U.S.A

    USGS Publications Warehouse

    Gettings, M.E.; Bultman, M.W.

    2005-01-01

    Some aquifers of the southwest Colorado Plateau, U.S.A., are deeply buried and overlain by several impermeable units, and thus recharge to the aquifer is probably mainly by seepage down penetrative fracture systems. This purpose of this study was to develop a method to map the location of candidate deep penetrative fractures over a 120,000 km2 area using gravity and aeromagnetic anomaly data together with surficial fracture data. The resulting database constitutes a spatially registered estimate of recharge location. Candidate deep fractures were obtained by spatial correlation of horizontal gradient and analytic signal maxima of gravity and magnetic anomalies vertically with major surficial lineaments obtained from geologic, topographic, side-looking airborne radar, and satellite imagery. The maps define a sub-set of possible penetrative fractures because of limitations of data coverage and the analysis technique. The data and techniques employed do not yield any indication as to whether fractures are open or closed. Correlations were carried out using image processing software in such a way that every pixel on the resulting grids was coded to uniquely identify which datasets correlated. The technique correctly identified known deep fracture systems and many new ones. Maps of the correlations also define in detail the tectonic fabrics of the Southwestern Colorado Plateau. Copyright ?? The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences; TERRAPUB.

  4. Mapping forest functional type in a forest-shrubland ecotone using SPOT imagery and predictive habitat distribution modelling

    USGS Publications Warehouse

    Assal, Timothy J.; Anderson, Patrick J.; Sibold, Jason

    2015-01-01

    The availability of land cover data at local scales is an important component in forest management and monitoring efforts. Regional land cover data seldom provide detailed information needed to support local management needs. Here we present a transferable framework to model forest cover by major plant functional type using aerial photos, multi-date Système Pour l’Observation de la Terre (SPOT) imagery, and topographic variables. We developed probability of occurrence models for deciduous broad-leaved forest and needle-leaved evergreen forest using logistic regression in the southern portion of the Wyoming Basin Ecoregion. The model outputs were combined into a synthesis map depicting deciduous and coniferous forest cover type. We evaluated the models and synthesis map using a field-validated, independent data source. Results showed strong relationships between forest cover and model variables, and the synthesis map was accurate with an overall correct classification rate of 0.87 and Cohen’s kappa value of 0.81. The results suggest our method adequately captures the functional type, size, and distribution pattern of forest cover in a spatially heterogeneous landscape.

  5. Using simulated maps to interpret the geochemistry, formation and quality of the Blue Gem Coal Bed, Kentucky, USA

    USGS Publications Warehouse

    Geboy, Nicholas J.; Olea, Ricardo A.; Engle, Mark A.; Martin-Fernandez, Jose Antonio

    2013-01-01

    This study presents geostatistical simulations of coal-quality parameters, major oxides and trace metals for an area covering roughly 812 km2 of the Blue Gem coal bed in southeastern Kentucky, USA. The Blue Gem, characterized by low ash yield and low sulfur content, is an important economic resource. Past studies have characterized the Blue Gem's geochemistry, palynology and petrography and inferred a depositional setting of a planar peat deposit that transitioned to slightly domed later in its development. These studies have focused primarily on vertical geochemical trends within the coal bed. Simulated maps of chemical elements derived from 45 measured sample locations across the study area provide an opportunity to observe changes in the horizontal direction within the coal bed. As the Blue Gem coal bed shows significant vertical chemical trends, care was taken in this study to try to select samples from a single, middle portion of the coal. By revealing spatial distribution patterns of elements across the middle of the bed, associations between different components of the coal can be seen. The maps therefore help to provide a picture of the coal-forming peat bog at an instant in geologic time and allow interpretation of a depositional setting in the horizontal direction. Results from this middle portion of the coal suggest an association of SiO2 with both K2O and TiO2 in different parts of the study area. Further, a pocket in the southeast of the study area shows elevated concentrations of elements attributable to observed carbonate-phase minerals (MgO, CaO, Ba and Sr) as well as elements commonly associated with sulfide-phase minerals (Cu, Mo and Ni). Areas of relatively high ash yield are observed in the north and south of the mapped area, in contrast to the low ash yields seen towards the east. Additionally, we present joint probability maps where multiple coal-quality parameters are plotted simultaneously on one figure. This application allows researchers

  6. Computational modelling of epidermal stratification highlights the importance of asymmetric cell division for predictable and robust layer formation

    PubMed Central

    Gord, Alexander; Holmes, William R.; Dai, Xing; Nie, Qing

    2014-01-01

    Skin is a complex organ tasked with, among other functions, protecting the body from the outside world. Its outermost protective layer, the epidermis, is comprised of multiple cell layers that are derived from a single-layered ectoderm during development. Using a new stochastic, multi-scale computational modelling framework, the anisotropic subcellular element method, we investigate the role of cell morphology and biophysical cell–cell interactions in the formation of this layered structure. This three-dimensional framework describes interactions between collections of hundreds to thousands of cells and (i) accounts for intracellular structure and morphology, (ii) easily incorporates complex cell–cell interactions and (iii) can be efficiently implemented on parallel architectures. We use this approach to construct a model of the developing epidermis that accounts for the internal polarity of ectodermal cells and their columnar morphology. Using this model, we show that cell detachment, which has been previously suggested to have a role in this process, leads to unpredictable, randomized stratification and that this cannot be abrogated by adjustment of cell–cell adhesion interaction strength. Polarized distribution of cell adhesion proteins, motivated by epithelial polarization, can however eliminate this detachment, and in conjunction with asymmetric cell division lead to robust and predictable development. PMID:25100322

  7. Developing LED UV fluorescence sensors for online monitoring DOM and predicting DBPs formation potential during water treatment.

    PubMed

    Li, Wen-Tao; Jin, Jing; Li, Qiang; Wu, Chen-Fei; Lu, Hai; Zhou, Qing; Li, Ai-Min

    2016-04-15

    Online monitoring dissolved organic matter (DOM) is urgent for water treatment management. In this study, high performance size exclusion chromatography with multi-UV absorbance and multi-emission fluorescence scans were applied to spectrally characterize samples from 16 drinking water sources across Yangzi River and Huai River Watersheds. The UV absorbance indices at 254 nm and 280 nm referred to the same DOM components and concentration, and the 280 nm UV light could excite both protein-like and humic-like fluorescence. Hence a novel UV fluorescence sensor was developed out using only one UV280 light-emitting diode (LED) as light source. For all samples, enhanced coagulation was mainly effective for large molecular weight biopolymers; while anion exchange further substantially removed humic substances. During chlorination tests, UVA280 and UVA254 showed similar correlations with yields of disinfection byproducts (DBPs); the humic-like fluorescence obtained from LED sensors correlated well with both trihalomethanes and haloacetic acids yields, while the correlation between protein-like fluorescence and trihalomethanes was relatively poor. Anion exchange exhibited more reduction of DBPs yields as well as UV absorbance and fluorescence signals than enhanced coagulation. The results suggest that the LED UV fluorescence sensors are very promising for online monitoring DOM and predicting DBPs formation potential during water treatment. PMID:26874469

  8. Developing LED UV fluorescence sensors for online monitoring DOM and predicting DBPs formation potential during water treatment.

    PubMed

    Li, Wen-Tao; Jin, Jing; Li, Qiang; Wu, Chen-Fei; Lu, Hai; Zhou, Qing; Li, Ai-Min

    2016-04-15

    Online monitoring dissolved organic matter (DOM) is urgent for water treatment management. In this study, high performance size exclusion chromatography with multi-UV absorbance and multi-emission fluorescence scans were applied to spectrally characterize samples from 16 drinking water sources across Yangzi River and Huai River Watersheds. The UV absorbance indices at 254 nm and 280 nm referred to the same DOM components and concentration, and the 280 nm UV light could excite both protein-like and humic-like fluorescence. Hence a novel UV fluorescence sensor was developed out using only one UV280 light-emitting diode (LED) as light source. For all samples, enhanced coagulation was mainly effective for large molecular weight biopolymers; while anion exchange further substantially removed humic substances. During chlorination tests, UVA280 and UVA254 showed similar correlations with yields of disinfection byproducts (DBPs); the humic-like fluorescence obtained from LED sensors correlated well with both trihalomethanes and haloacetic acids yields, while the correlation between protein-like fluorescence and trihalomethanes was relatively poor. Anion exchange exhibited more reduction of DBPs yields as well as UV absorbance and fluorescence signals than enhanced coagulation. The results suggest that the LED UV fluorescence sensors are very promising for online monitoring DOM and predicting DBPs formation potential during water treatment.

  9. Evaluation of Interindividual Human Variation in Bioactivation and DNA Adduct Formation of Estragole in Liver Predicted by Physiologically Based Kinetic/Dynamic and Monte Carlo Modeling.

    PubMed

    Punt, Ans; Paini, Alicia; Spenkelink, Albertus; Scholz, Gabriele; Schilter, Benoit; van Bladeren, Peter J; Rietjens, Ivonne M C M

    2016-04-18

    Estragole is a known hepatocarcinogen in rodents at high doses following metabolic conversion to the DNA-reactive metabolite 1'-sulfooxyestragole. The aim of the present study was to model possible levels of DNA adduct formation in (individual) humans upon exposure to estragole. This was done by extending a previously defined PBK model for estragole in humans to include (i) new data on interindividual variation in the kinetics for the major PBK model parameters influencing the formation of 1'-sulfooxyestragole, (ii) an equation describing the relationship between 1'-sulfooxyestragole and DNA adduct formation, (iii) Monte Carlo modeling to simulate interindividual human variation in DNA adduct formation in the population, and (iv) a comparison of the predictions made to human data on DNA adduct formation for the related alkenylbenzene methyleugenol. Adequate model predictions could be made, with the predicted DNA adduct levels at the estimated daily intake of estragole of 0.01 mg/kg bw ranging between 1.6 and 8.8 adducts in 10(8) nucleotides (nts) (50th and 99th percentiles, respectively). This is somewhat lower than values reported in the literature for the related alkenylbenzene methyleugenol in surgical human liver samples. The predicted levels seem to be below DNA adduct levels that are linked with tumor formation by alkenylbenzenes in rodents, which were estimated to amount to 188-500 adducts per 10(8) nts at the BMD10 values of estragole and methyleugenol. Although this does not seem to point to a significant health concern for human dietary exposure, drawing firm conclusions may have to await further validation of the model's predictions. PMID:26952143

  10. Does Preinterventional Flat-Panel Computer Tomography Pooled Blood Volume Mapping Predict Final Infarct Volume After Mechanical Thrombectomy in Acute Cerebral Artery Occlusion?

    SciTech Connect

    Wagner, Marlies; Kyriakou, Yiannis; Mesnil de Rochemont, Richard du; Singer, Oliver C.; Berkefeld, Joachim

    2013-08-01

    PurposeDecreased cerebral blood volume is known to be a predictor for final infarct volume in acute cerebral artery occlusion. To evaluate the predictability of final infarct volume in patients with acute occlusion of the middle cerebral artery (MCA) or the distal internal carotid artery (ICA) and successful endovascular recanalization, pooled blood volume (PBV) was measured using flat-panel detector computed tomography (FPD CT).Materials and MethodsTwenty patients with acute unilateral occlusion of the MCA or distal ACI without demarcated infarction, as proven by CT at admission, and successful Thrombolysis in cerebral infarction score (TICI 2b or 3) endovascular thrombectomy were included. Cerebral PBV maps were acquired from each patient immediately before endovascular thrombectomy. Twenty-four hours after recanalization, each patient underwent multislice CT to visualize final infarct volume. Extent of the areas of decreased PBV was compared with the final infarct volume proven by follow-up CT the next day.ResultsIn 15 of 20 patients, areas of distinct PBV decrease corresponded to final infarct volume. In 5 patients, areas of decreased PBV overestimated final extension of ischemia probably due to inappropriate timing of data acquisition and misery perfusion.ConclusionPBV mapping using FPD CT is a promising tool to predict areas of irrecoverable brain parenchyma in acute thromboembolic stroke. Further validation is necessary before routine use for decision making for interventional thrombectomy.

  11. Multinomial Logistic Regression Predicted Probability Map To Visualize The Influence Of Socio-Economic Factors On Breast Cancer Occurrence in Southern Karnataka

    NASA Astrophysics Data System (ADS)

    Madhu, B.; Ashok, N. C.; Balasubramanian, S.

    2014-11-01

    Multinomial logistic regression analysis was used to develop statistical model that can predict the probability of breast cancer in Southern Karnataka using the breast cancer occurrence data during 2007-2011. Independent socio-economic variables describing the breast cancer occurrence like age, education, occupation, parity, type of family, health insurance coverage, residential locality and socioeconomic status of each case was obtained. The models were developed as follows: i) Spatial visualization of the Urban- rural distribution of breast cancer cases that were obtained from the Bharat Hospital and Institute of Oncology. ii) Socio-economic risk factors describing the breast cancer occurrences were complied for each case. These data were then analysed using multinomial logistic regression analysis in a SPSS statistical software and relations between the occurrence of breast cancer across the socio-economic status and the influence of other socio-economic variables were evaluated and multinomial logistic regression models were constructed. iii) the model that best predicted the occurrence of breast cancer were identified. This multivariate logistic regression model has been entered into a geographic information system and maps showing the predicted probability of breast cancer occurrence in Southern Karnataka was created. This study demonstrates that Multinomial logistic regression is a valuable tool for developing models that predict the probability of breast cancer Occurrence in Southern Karnataka.

  12. Testing the potential for predictive modeling and mapping and extending its use as a tool for evaluating management scenarios and economic valuation in the Baltic Sea (PREHAB).

    PubMed

    Lindegarth, Mats; Bergström, Ulf; Mattila, Johanna; Olenin, Sergej; Ollikainen, Markku; Downie, Anna-Leena; Sundblad, Göran; Bučas, Martynas; Gullström, Martin; Snickars, Martin; von Numers, Mikael; Svensson, J Robin; Kosenius, Anna-Kaisa

    2014-02-01

    We evaluated performance of species distribution models for predictive mapping, and how models can be used to integrate human pressures into ecological and economic assessments. A selection of 77 biological variables (species, groups of species, and measures of biodiversity) across the Baltic Sea were modeled. Differences among methods, areas, predictor, and response variables were evaluated. Several methods successfully predicted abundance and occurrence of vegetation, invertebrates, fish, and functional aspects of biodiversity. Depth and substrate were among the most important predictors. Models incorporating water clarity were used to predict increasing cover of the brown alga bladderwrack Fucus vesiculosus and increasing reproduction area of perch Perca fluviatilis, but decreasing reproduction areas for pikeperch Sander lucioperca following successful implementation of the Baltic Sea Action Plan. Despite variability in estimated non-market benefits among countries, such changes were highly valued by citizens in the three Baltic countries investigated. We conclude that predictive models are powerful and useful tools for science-based management of the Baltic Sea.

  13. Three-Dimensional Mapping of Magnetic Strata From Aeromagnetic Anomalies: The Deformed Neroly Formation South of Mt. Diablo, Northern California

    NASA Astrophysics Data System (ADS)

    Jachens, R. C.; Simpson, R. W.; Graymer, R. W.; Wentworth, C. M.

    2008-12-01

    We apply direct inversion of aeromagnetic anomalies to analyze the subsurface 3D shape of the highly magnetic Miocene Neroly Formation, which consists largely of medium to coarse-grained andesitic sandstones containing abundant magnetite. The Neroly Formation is widespread in the eastern San Francisco Bay region, and locally is tightly folded and disrupted by faulting in the compressional regime related to the left-stepping (restraining) connection between the strike-slip Greenville and Concord Faults. The inversion technique is based on the conversion of the anomalies produced by a magnetic layer to their equivalent magnetic potential (psuedogravity) anomalies, manipulation of these anomalies to produce anomalies that would result from a half-space with a variable-depth top having the shape of the top surface of the layer, and then inverting these pseudogravity anomalies for the shape of that top surface. Assumptions include a constant layer thickness, uniform magnetization which implies a constant pseudodensity contrast, and a surface that is single-valued (no recumbent folds or strata repeated with depth). Constraints on 3D position are applied where the layer crops out or is at a depth known from well or other information. Application of this inversion technique to aeromagnetic anomalies over the Neroly Formation yields a complex top surface characterized by elongate overlapping troughs and structural highs, including the well-known Tassajara anticline and adjacent Sycamore Valley syncline. Troughs are true synclinal lows whereas the structural highs may be fold crests, steep truncated strata, and/or fault duplicated strata. The strongest deformation is confined to within ~7 km of the near-vertical overturned Neroly beds that crop out along the NE margin of the valley, and is characterized by four laterally overlapping, margin parallel structural highs and intervening troughs, each between 10 and 20 km in length. A fifth possible structural high lies farther SW

  14. Alteration mineral mapping and metallogenic prediction using CASI/SASI airborne hyperspectral data in Mingshujing area of Gansu Province, NW China

    NASA Astrophysics Data System (ADS)

    Sun, Yu; Zhao, Yingjun; Qin, Kai; Tian, Feng

    2016-04-01

    Hyperspectral remote sensing is a frontier of remote sensing. Due to its advantage of integrated image with spectrum, it can realize objects identification, superior to objects classification of multispectral remote sensing. Taken the Mingshujing area in Gansu Province of China as an example, this study extracted the alteration minerals and thus to do metallogenic prediction using CASI/SASI airborne hyperspectral data. The Mingshujing area, located in Liuyuan region of Gansu Province, is dominated by middle Variscan granites and Indosinian granites, with well developed EW- and NE-trending faults. In July 2012, our project team obtained the CASI/SASI hyperspectral data of Liuyuan region by aerial flight. The CASI hyperspectral data have 32 bands and the SASI hyperspectral data have 88 bands, with spectral resolution of 15nm for both. The hyperspectral raw data were first preprocessed, including radiometric correction and geometric correction. We then conducted atmospheric correction using empirical line method based on synchronously measured ground spectra to obtain hyperspectral reflectance data. Spectral dimension of hyperspectral data was reduced by the minimum noise fraction transformation method, and then purity pixels were selected. After these steps, image endmember spectra were obtained. We used the endmember spectrum election method based on expert knowledge to analyze the image endmember spectra. Then, the mixture tuned matched filter (MTMF) mapping method was used to extract mineral information, including limonite, Al-rich sericite, Al-poor sericite and chlorite. Finally, the distribution of minerals in the Mingshujing area was mapped. According to the distribution of limonite and Al-rich sericite mapped by CASI/SASI hyperspectral data, we delineated five gold prospecting areas, and further conducted field verification in these areas. It is shown that there are significant gold mineralized anomalies in surface in the Baixianishan and Xitan prospecting

  15. Quantitative Computed Tomography Protocols Affect Material Mapping and Quantitative Computed Tomography-Based Finite-Element Analysis Predicted Stiffness.

    PubMed

    Giambini, Hugo; Dragomir-Daescu, Dan; Nassr, Ahmad; Yaszemski, Michael J; Zhao, Chunfeng

    2016-09-01

    Quantitative computed tomography-based finite-element analysis (QCT/FEA) has become increasingly popular in an attempt to understand and possibly reduce vertebral fracture risk. It is known that scanning acquisition settings affect Hounsfield units (HU) of the CT voxels. Material properties assignments in QCT/FEA, relating HU to Young's modulus, are performed by applying empirical equations. The purpose of this study was to evaluate the effect of QCT scanning protocols on predicted stiffness values from finite-element models. One fresh frozen cadaveric torso and a QCT calibration phantom were scanned six times varying voltage and current and reconstructed to obtain a total of 12 sets of images. Five vertebrae from the torso were experimentally tested to obtain stiffness values. QCT/FEA models of the five vertebrae were developed for the 12 image data resulting in a total of 60 models. Predicted stiffness was compared to the experimental values. The highest percent difference in stiffness was approximately 480% (80 kVp, 110 mAs, U70), while the lowest outcome was ∼1% (80 kVp, 110 mAs, U30). There was a clear distinction between reconstruction kernels in predicted outcomes, whereas voltage did not present a clear influence on results. The potential of QCT/FEA as an improvement to conventional fracture risk prediction tools is well established. However, it is important to establish research protocols that can lead to results that can be translated to the clinical setting. PMID:27428281

  16. Evaluation of Ground-Motion Modeling Techniques for Use in Global ShakeMap - A Critique of Instrumental Ground-Motion Prediction Equations, Peak Ground Motion to Macroseismic Intensity Conversions, and Macroseismic Intensity Predictions in Different Tectonic Settings

    USGS Publications Warehouse

    Allen, Trevor I.; Wald, David J.

    2009-01-01

    Regional differences in ground-motion attenuation have long been thought to add uncertainty in the prediction of ground motion. However, a growing body of evidence suggests that regional differences in ground-motion attenuation may not be as significant as previously thought and that the key differences between regions may be a consequence of limitations in ground-motion datasets over incomplete magnitude and distance ranges. Undoubtedly, regional differences in attenuation can exist owing to differences in crustal structure and tectonic setting, and these can contribute to differences in ground-motion attenuation at larger source-receiver distances. Herein, we examine the use of a variety of techniques for the prediction of several ground-motion metrics (peak ground acceleration and velocity, response spectral ordinates, and macroseismic intensity) and compare them against a global dataset of instrumental ground-motion recordings and intensity assignments. The primary goal of this study is to determine whether existing ground-motion prediction techniques are applicable for use in the U.S. Geological Survey's Global ShakeMap and Prompt Assessment of Global Earthquakes for Response (PAGER). We seek the most appropriate ground-motion predictive technique, or techniques, for each of the tectonic regimes considered: shallow active crust, subduction zone, and stable continental region.

  17. Flow network QSAR for the prediction of physicochemical properties by mapping an electrical resistance network onto a chemical reaction poset.

    PubMed

    Ivanciuc, Ovidiu; Ivanciuc, Teodora; Klein, Douglas J

    2013-06-01

    Usual quantitative structure-activity relationship (QSAR) models are computed from unstructured input data, by using a vector of molecular descriptors for each chemical in the dataset. Another alternative is to consider the structural relationships between the chemical structures, such as molecular similarity, presence of certain substructures, or chemical transformations between compounds. We defined a class of network-QSAR models based on molecular networks induced by a sequence of substitution reactions on a chemical structure that generates a partially ordered set (or poset) oriented graph that may be used to predict various molecular properties with quantitative superstructure-activity relationships (QSSAR). The network-QSAR interpolation models defined on poset graphs, namely average poset, cluster expansion, and spline poset, were tested with success for the prediction of several physicochemical properties for diverse chemicals. We introduce the flow network QSAR, a new poset regression model in which the dataset of chemicals, represented as a reaction poset, is transformed into an oriented network of electrical resistances in which the current flow results in a potential at each node. The molecular property considered in the QSSAR model is represented as the electrical potential, and the value of this potential at a particular node is determined by the electrical resistances assigned to each edge and by a system of batteries. Each node with a known value for the molecular property is attached to a battery that sets the potential on that node to the value of the respective molecular property, and no external battery is attached to nodes from the prediction set, representing chemicals for which the values of the molecular property are not known or are intended to be predicted. The flow network QSAR algorithm determines the values of the molecular property for the prediction set of molecules by applying Ohm's law and Kirchhoff's current law to the poset

  18. Predicting density functional theory total energies and enthalpies of formation of metal-nonmetal compounds by linear regression

    NASA Astrophysics Data System (ADS)

    Deml, Ann M.; O'Hayre, Ryan; Wolverton, Chris; Stevanović, Vladan

    2016-02-01

    The availability of quantitatively accurate total energies (Etot) of atoms, molecules, and solids, enabled by the development of density functional theory (DFT), has transformed solid state physics, quantum chemistry, and materials science by allowing direct calculations of measureable quantities, such as enthalpies of formation (Δ Hf ). Still, the ability to compute Etot and Δ Hf values does not, necessarily, provide insights into the physical mechanisms behind their magnitudes or chemical trends. Here, we examine a large set of calculated Etot and Δ Hf values obtained from the DFT+U -based fitted elemental-phase reference energies (FERE) approach [V. Stevanović, S. Lany, X. Zhang, and A. Zunger, Phys. Rev. B 85, 115104 (2012), 10.1103/PhysRevB.85.115104] to probe relationships between the Etot/Δ Hf of metal-nonmetal compounds in their ground-state crystal structures and properties describing the compound compositions and their elemental constituents. From a stepwise linear regression, we develop a linear model for Etot, and consequently Δ Hf , that reproduces calculated FERE values with a mean absolute error of ˜80 meV/atom. The most significant contributions to the model include calculated total energies of the constituent elements in their reference phases (e.g., metallic iron or gas phase O2), atomic ionization energies and electron affinities, Pauling electronegativity differences, and atomic electric polarizabilities. These contributions are discussed in the context of their connection to the underlying physics. We also demonstrate that our Etot/Δ Hf model can be directly extended to predict the Etot and Δ Hf of compounds outside the set used to develop the model.

  19. An Integrated Modeling Approach for Predicting Process Maps of Residual Stress and Distortion in a Laser Weld: A Combined CFD-FE Methodology

    NASA Astrophysics Data System (ADS)

    Turner, Richard P.; Panwisawas, Chinnapat; Sovani, Yogesh; Perumal, Bama; Ward, R. Mark; Brooks, Jeffery W.; Basoalto, Hector C.

    2016-07-01

    Laser welding has become an important joining methodology within a number of industries for the structural joining of metallic parts. It offers a high power density welding capability which is desirable for deep weld sections, but is equally suited to performing thinner welded joints with sensible amendments to key process variables. However, as with any welding process, the introduction of severe thermal gradients at the weld line will inevitably lead to process-induced residual stress formation and distortions. Finite element (FE) predictions for weld simulation have been made within academia and industrial research for a number of years, although given the fluid nature of the molten weld pool, FE methodologies have limited capabilities. An improvement upon this established method would be to incorporate a computational fluid dynamics (CFD) model formulation prior to the FE model, to predict the weld pool shape and fluid flow, such that details can be fed into FE from CFD as a starting condition. The key outputs of residual stress and distortions predicted by the FE model can then be monitored against the process variables input to the model. Further, a link between the thermal results and the microstructural properties is of interest. Therefore, an empirical relationship between lamellar spacing and the cooling rate was developed and used to make predictions about the lamellar spacing for welds of different process parameters. Processing parameter combinations that lead to regions of high residual stress formation and high distortion have been determined, and the impact of processing parameters upon the predicted lamellar spacing has been presented.

  20. An Integrated Modeling Approach for Predicting Process Maps of Residual Stress and Distortion in a Laser Weld: A Combined CFD-FE Methodology

    NASA Astrophysics Data System (ADS)

    Turner, Richard P.; Panwisawas, Chinnapat; Sovani, Yogesh; Perumal, Bama; Ward, R. Mark; Brooks, Jeffery W.; Basoalto, Hector C.

    2016-10-01

    Laser welding has become an important joining methodology within a number of industries for the structural joining of metallic parts. It offers a high power density welding capability which is desirable for deep weld sections, but is equally suited to performing thinner welded joints with sensible amendments to key process variables. However, as with any welding process, the introduction of severe thermal gradients at the weld line will inevitably lead to process-induced residual stress formation and distortions. Finite element (FE) predictions for weld simulation have been made within academia and industrial research for a number of years, although given the fluid nature of the molten weld pool, FE methodologies have limited capabilities. An improvement upon this established method would be to incorporate a computational fluid dynamics (CFD) model formulation prior to the FE model, to predict the weld pool shape and fluid flow, such that details can be fed into FE from CFD as a starting condition. The key outputs of residual stress and distortions predicted by the FE model can then be monitored against the process variables input to the model. Further, a link between the thermal results and the microstructural properties is of interest. Therefore, an empirical relationship between lamellar spacing and the cooling rate was developed and used to make predictions about the lamellar spacing for welds of different process parameters. Processing parameter combinations that lead to regions of high residual stress formation and high distortion have been determined, and the impact of processing parameters upon the predicted lamellar spacing has been presented.

  1. Solitary fibrous tumor of the pleura: apparent diffusion coefficient (ADC) value and ADC map to predict malignant transformation.

    PubMed

    Inaoka, Tsutomu; Takahashi, Koji; Miyokawa, Naoyuki; Ohsaki, Yoshinobu; Aburano, Tamio

    2007-07-01

    Solitary fibrous tumors (SFTs) of the pleura are rare soft-tissue tumors that are presumed to be of mesenchymal origin. Most SFTs are histologically benign, but up to 20% of SFTs may be malignant. In addition, malignant transformation may occur within histologically benign SFTs, though it is rare. However, it is difficult to diagnose malignant SFTs of the pleura by means of conventional computed tomography and magnetic resonance imaging (MRI). In this article we present the first case of malignant SFT of the pleura in an 81-year-old man in which the apparent diffusion coefficient (ADC) value and ADC map based on diffusion-weighted MRI were very useful for identifying malignant transformation.

  2. Natural history of left ventricular size and function after acute myocardial infarction. Assessment and prediction by echocardiographic endocardial surface mapping.

    PubMed

    Picard, M H; Wilkins, G T; Ray, P A; Weyman, A E

    1990-08-01

    To investigate the natural history of regional dyssynergy and left ventricular size after myocardial infarction, 57 patients with a first Q wave myocardial infarction (18 anterior, 35 inferior, and four apical by echocardiography) were studied by two-dimensional echocardiography and compared with 30 control patients. Measurements from the echocardiograms were used to construct maps of the left ventricular endocardial surface from which the endocardial surface area index (ESAi) and the percent of the endocardial surface area involved by abnormal wall motion (%AWM) were calculated. The maps from entry and 3-month echocardiograms were used to classify patients based on changes in ESAi and abnormal wall motion. Two subgroups of patients were identified at entry--those with a normal ESAi (group 1, n = 50) and those with an increased ESAi (group 2, n = 7). Group 1 patients was subdivided at 3 months by changes occurring in ESAi (1A, 5% increase [n = 19]; 1B, no change [n = 23]; 1C, 5% decrease [n = 8]). The increase in ESAi (64.9 +/- 5.2 to 75.4 +/- 7.5 cm2/m2, p less than 0.0001) in group 1A was associated with global ventricular dilatation (n = 11) and clinically silent infarct extension (n = 8). Groups 1B and 1C were composed predominantly of patients with inferior infarctions, and all exhibited either no change or a significant decrease in infarct size (infarct regression). Group 2 patients demonstrated a continued increase in ESAi by 3 months (88.2 +/- 10.0 to 101.4 +/- 15.5 cm2/m2, p less than 0.007). This group comprised only patients with anterior infarctions, and all exhibited infarct expansion at the left ventricular apex. The changes in left ventricular size and functional infarct size are heterogeneous after acute myocardial infarction and relate to the initial endocardial surface area, infarct location, and functional infarct size. PMID:2372895

  3. SEQUENTIAL STAR FORMATION IN THE Sh 254-258 MOLECULAR CLOUD: HEINRICH HERTZ TELESCOPE MAPS OF CO J = 2-1 AND 3-2 EMISSION

    SciTech Connect

    Bieging, John H.; Peters, William L.; Schlottman, Keith; Kulesa, Craig; Vila Vilaro, Baltasar

    2009-09-15

    The molecular cloud associated with the Sh 254-258 group of five small H II regions appears to be forming a (late)-OB association. We have mapped the associated molecular cloud in the J = 2-1 line of the CO and {sup 13}CO molecules over 0.{sup 0}75 x 1{sup 0}, and the CO J = 3-2 line toward the two main peaks, with the University of Arizona Heinrich Hertz Submillimeter Telescope. The data are analyzed with a statistical equilibrium code to estimate physical properties of the molecular gas. We compare the molecular cloud morphology with images at optical, IR, and radio wavelengths. From this analysis, we propose a scenario for sequential formation of the stars exciting the H II regions, triggered by the compression of the molecular gas as a consequence of the expansion of the adjacent H II regions.

  4. Sequential Star Formation in the Sh 254-258 Molecular Cloud: Heinrich Hertz Telescope Maps of CO J = 2-1 and 3-2 Emission

    NASA Astrophysics Data System (ADS)

    Bieging, John H.; Peters, William L.; Vila Vilaro, Baltasar; Schlottman, Keith; Kulesa, Craig

    2009-09-01

    The molecular cloud associated with the Sh 254-258 group of five small H II regions appears to be forming a (late)-OB association. We have mapped the associated molecular cloud in the J = 2-1 line of the CO and 13CO molecules over 0fdg75 × 1°, and the CO J = 3-2 line toward the two main peaks, with the University of Arizona Heinrich Hertz Submillimeter Telescope. The data are analyzed with a statistical equilibrium code to estimate physical properties of the molecular gas. We compare the molecular cloud morphology with images at optical, IR, and radio wavelengths. From this analysis, we propose a scenario for sequential formation of the stars exciting the H II regions, triggered by the compression of the molecular gas as a consequence of the expansion of the adjacent H II regions.

  5. Combining solvent thermodynamic profiles with functionality maps of the Hsp90 binding site to predict the displacement of water molecules.

    PubMed

    Haider, Kamran; Huggins, David J

    2013-10-28

    Intermolecular interactions in the aqueous phase must compete with the interactions between the two binding partners and their solvating water molecules. In biological systems, water molecules in protein binding sites cluster at well-defined hydration sites and can form strong hydrogen-bonding interactions with backbone and side-chain atoms. Displacement of such water molecules is only favorable when the ligand can form strong compensating hydrogen bonds. Conversely, water molecules in hydrophobic regions of protein binding sites make only weak interactions, and the requirements for favorable displacement are less stringent. The propensity of water molecules for displacement can be identified using inhomogeneous fluid solvation theory (IFST), a statistical mechanical method that decomposes the solvation free energy of a solute into the contributions from different spatial regions and identifies potential binding hotspots. In this study, we employed IFST to study the displacement of water molecules from the ATP binding site of Hsp90, using a test set of 103 ligands. The predicted contribution of a hydration site to the hydration free energy was found to correlate well with the observed displacement. Additionally, we investigated if this correlation could be improved by using the energetic scores of favorable probe groups binding at the location of hydration sites, derived from a multiple copy simultaneous search (MCSS) method. The probe binding scores were not highly predictive of the observed displacement and did not improve the predictivity when used in combination with IFST-based hydration free energies. The results show that IFST alone can be used to reliably predict the observed displacement of water molecules in Hsp90. However, MCSS can augment IFST calculations by suggesting which functional groups should be used to replace highly displaceable water molecules. Such an approach could be very useful in improving the hit-to-lead process for new drug targets.

  6. Non-twist map bifurcation of drift-lines and drift-island formation in saturated 3D MHD equilibria

    NASA Astrophysics Data System (ADS)

    Pfefferle, David; Cooper, Wilfred A.; Graves, Jonathan P.

    2015-11-01

    Based on non-canonical perturbation theory, guiding-centre drift equations are identified as perturbed magnetic field-line equations. The topology of passing-particle orbits, called drift-lines, is completely determined by the magnetic configuration. In axisymmetric tokamak fields, drift-lines lie on shifted flux-surfaces, called drift-surfaces. Field-lines and drift-lines are subject to island structures at rational surfaces only when a non-axisymmetric component is added. The picture is different in the case of 3D saturated MHD equilibrium like the helical core associated with a non-resonant internal kink mode. In assuming nested flux-surfaces, these bifurcated states, expected for a reversed q-profile with qmin close yet above unity and conveniently obtained in VMEC, feature integrable field-lines. The helical drift-lines however become resonant with the axisymmetric component in the region of qmin and spontaneously generate drift-islands. Due to the locally reversed sheared q-profile, the drift-island structure follows the bifurcation/reconnection mechanism of non-twist maps. This result provides a theoretical interpretation of NBI fast ion helical hot-spots in Long-Lived Modes as well as snake-like impurity density accumulation in internal MHD activity.

  7. Use of Improved Orbitals for CCSD(T) Calculations for Predicting Heats of Formation of Group IV and Group VI Metal Oxide Monomers and Dimers and UCl6.

    PubMed

    Fang, Zongtang; Lee, Zachary; Peterson, Kirk A; Dixon, David A

    2016-08-01

    The prediction of the heats of formation of group IV and group VI metal oxide monomers and dimers with the coupled cluster CCSD(T) method has been improved by using Kohn-Sham density functional theory (DFT) and Brueckner orbitals for the initial wave function. The valence and core-valence contributions to the total atomization energies for the CrO3 monomer and dimer are predicted to be significantly larger than when using the Hartree-Fock (HF) orbitals. The predicted heat of formation of CrO3 with CCSD(T)/PW91 is consistent with previous calculations including high-order corrections beyond CCSD(T) and agrees well with the experiment. The improved heats of formation with the DFT and Brueckner orbitals are due to these orbitals being closer to the actual orbitals. Pure DFT functionals perform slightly better than the hybrid B3LYP functional due to the presence of exact exchange in the hybrid functional. Comparable heats of formation for TiO2 and the second- and the third-row group IV and group VI metal oxides are predicted well using either the DFT PW91 orbitals, Brueckner orbitals, or HF orbitals. The normalized clustering energies for the dimers are consistent with our previous work except for a larger value predicted for Cr2O6. The prediction of the reaction energy for UF6 + 3Cl2 → UCl6 + 3F2 was significantly improved with the use of DFT or Brueckner orbitals as compared to HF orbitals. PMID:27398941

  8. DAM - detection and mapping

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Integrated set of manual procedures, computer programs, and graphic devices processes multispectral scanner data from orbiting Landsat into precisely registered and formatted maps of surface water and other resources at variety of scales, sheet formats, and tick intervals.

  9. Isopach and isoresource maps for oil shale deposits in the Eocene Green River Formation for the combined Uinta and Piceance Basins, Utah and Colorado

    USGS Publications Warehouse

    Mercier, Tracey J.; Johnson, Ronald C.

    2012-01-01

    The in-place oil shale resources in the Eocene Green River Formation of the Piceance Basin of western Colorado and the Uinta Basin of western Colorado and eastern Utah are estimated at 1.53 trillion barrels and 1.32 trillion barrels, respectively. The oil shale strata were deposited in a single large saline lake, Lake Uinta, that covered both basins and the intervening Douglas Creek arch, an area of comparatively low rates of subsidence throughout the history of Lake Uinta. Although the Green River Formation is largely eroded for about a 20-mile area along the crest of the arch, the oil shale interval is similar in both basins, and 17 out of 18 of the assessed oil shale zones are common to both basins. Assessment maps for these 17 zones are combined so that the overall distribution of oil shale over the entire extent of Lake Uinta can be studied. The combined maps show that throughout most of the history of Lake Uinta, the richest oil shale was deposited in the depocenter in the north-central part of the Piceance Basin and in the northeast corner of the Uinta Basin where it is closest to the Piceance Basin, which is the only area of the Uinta Basin where all of the rich and lean oil shale zones, originally defined in the Piceance Basin, can be identified. Both the oil shale and saline mineral depocenter in the Piceance Basin and the richest oil shale area in the Uinta Basin were in areas with comparatively low rates of subsidence during Lake Uinta time, but both areas had low rates of clastic influx. Limiting clastic influx rather than maximizing subsidence appears to have been the most important factor in producing rich oil shale.

  10. Connecting gene expression data from connectivity map and in silico target predictions for small molecule mechanism-of-action analysis.

    PubMed

    Ravindranath, Aakash Chavan; Perualila-Tan, Nolen; Kasim, Adetayo; Drakakis, Georgios; Liggi, Sonia; Brewerton, Suzanne C; Mason, Daniel; Bodkin, Michael J; Evans, David A; Bhagwat, Aditya; Talloen, Willem; Göhlmann, Hinrich W H; Shkedy, Ziv; Bender, Andreas

    2015-01-01

    Integrating gene expression profiles with certain proteins can improve our understanding of the fundamental mechanisms in protein-ligand binding. This paper spotlights the integration of gene expression data and target prediction scores, providing insight into mechanism of action (MoA). Compounds are clustered based upon the similarity of their predicted protein targets and each cluster is linked to gene sets using Linear Models for Microarray Data. MLP analysis is used to generate gene sets based upon their biological processes and a qualitative search is performed on the homogeneous target-based compound clusters to identify pathways. Genes and proteins were linked through pathways for 6 of the 8 MCF7 and 6 of the 11 PC3 clusters. Three compound clusters are studied; (i) the target-driven cluster involving HSP90 inhibitors, geldanamycin and tanespimycin induces differential expression for HSP90-related genes and overlap with pathway response to unfolded protein. Gene expression results are in agreement with target prediction and pathway annotations add information to enable understanding of MoA. (ii) The antipsychotic cluster shows differential expression for genes LDLR and INSIG-1 and is predicted to target CYP2D6. Pathway steroid metabolic process links the protein and respective genes, hypothesizing the MoA for antipsychotics. A sub-cluster (verepamil and dexverepamil), although sharing similar protein targets with the antipsychotic drug cluster, has a lower intensity of expression profile on related genes, indicating that this method distinguishes close sub-clusters and suggests differences in their MoA. Lastly, (iii) the thiazolidinediones drug cluster predicted peroxisome proliferator activated receptor (PPAR) PPAR-alpha, PPAR-gamma, acyl CoA desaturase and significant differential expression of genes ANGPTL4, FABP4 and PRKCD. The targets and genes are linked via PPAR signalling pathway and induction of apoptosis, generating a hypothesis for the MoA of

  11. Geologic Map of the Meskhent Tessera Quadrangle (V-3), Venus: Evidence for Early Formation and Preservation of Regional Topography

    NASA Technical Reports Server (NTRS)

    Ivanov, M. A.; Head, James W.

    2008-01-01

    The area of the Meskhent Tessera quadrangle (V-3, 50-75degN, 60-120degE, Fig. 1) corresponds to a transition zone from the uplands of Ishtar Terra to the west to the lowlands of Atalanta Planitia to the east. The topographic configuration, gravity signature, and presence of large tesserae in Ishtar Terra are consistent with extensive areas of thickened crust and tectonically stabilized lithosphere representing ancient and now extinct regimes of mantle convection. The gravity and topographic characteristics of Atalanta Planitia have been cited as evidence for large-scale mantle downwelling. Thus, the region of Meskhent Tessera quadrangle represents an important sample for the study of the regional history of long-wavelength topography (highlands, midlands, and lowlands), interaction between the downwelling and areas of thickened crust/lithosphere, formation of associated tectonic features, and emplacement of volcanic plains.

  12. Comprehensive mapping and characteristic regimes of aerosol effects on the formation and evolution of pyro-convective clouds

    SciTech Connect

    Chang, D.; Cheng, Y.; Reutter, P.; Trentmann, J.; Burrows, S. M.; Spichtinger, P.; Nordmann, S.; Andreae, M. O.; Poschl, U.; Su, H.

    2015-09-21

    Here, a recent parcel model study (Reutter et al., 2009) showed three deterministic regimes of initial cloud droplet formation, characterized by different ratios of aerosol concentrations (NCN) to updraft velocities. This analysis, however, did not reveal how these regimes evolve during the subsequent cloud development. To address this issue, we employed the Active Tracer High Resolution Atmospheric Model (ATHAM) with full microphysics and extended the model simulation from the cloud base to the entire column of a single pyro-convective mixed-phase cloud. A series of 2-D simulations (over 1000) were performed over a wide range of NCN and dynamic conditions. The integrated concentration of hydrometeors over the full spatial and temporal scales was used to evaluate the aerosol and dynamic effects. The results show the following. (1) The three regimes for cloud condensation nuclei (CCN) activation in the parcel model (namely aerosol-limited, updraft-limited, and transitional regimes) still exist within our simulations, but net production of raindrops and frozen particles occurs mostly within the updraft-limited regime. (2) Generally, elevated aerosols enhance the formation of cloud droplets and frozen particles. The response of raindrops and precipitation to aerosols is more complex and can be either positive or negative as a function of aerosol concentrations. The most negative effect was found for values of NCN of ~ 1000 to 3000 cm–3. (3) The nonlinear properties of aerosol–cloud interactions challenge the conclusions drawn from limited case studies in terms of their representativeness, and ensemble studies over a wide range of aerosol concentrations and other influencing factors are strongly recommended for a more robust assessment of the aerosol effects.

  13. Comprehensive mapping and characteristic regimes of aerosol effects on the formation and evolution of pyro-convective clouds

    DOE PAGES

    Chang, D.; Cheng, Y.; Reutter, P.; Trentmann, J.; Burrows, S. M.; Spichtinger, P.; Nordmann, S.; Andreae, M. O.; Poschl, U.; Su, H.

    2015-09-21

    Here, a recent parcel model study (Reutter et al., 2009) showed three deterministic regimes of initial cloud droplet formation, characterized by different ratios of aerosol concentrations (NCN) to updraft velocities. This analysis, however, did not reveal how these regimes evolve during the subsequent cloud development. To address this issue, we employed the Active Tracer High Resolution Atmospheric Model (ATHAM) with full microphysics and extended the model simulation from the cloud base to the entire column of a single pyro-convective mixed-phase cloud. A series of 2-D simulations (over 1000) were performed over a wide range of NCN and dynamic conditions. Themore » integrated concentration of hydrometeors over the full spatial and temporal scales was used to evaluate the aerosol and dynamic effects. The results show the following. (1) The three regimes for cloud condensation nuclei (CCN) activation in the parcel model (namely aerosol-limited, updraft-limited, and transitional regimes) still exist within our simulations, but net production of raindrops and frozen particles occurs mostly within the updraft-limited regime. (2) Generally, elevated aerosols enhance the formation of cloud droplets and frozen particles. The response of raindrops and precipitation to aerosols is more complex and can be either positive or negative as a function of aerosol concentrations. The most negative effect was found for values of NCN of ~ 1000 to 3000 cm–3. (3) The nonlinear properties of aerosol–cloud interactions challenge the conclusions drawn from limited case studies in terms of their representativeness, and ensemble studies over a wide range of aerosol concentrations and other influencing factors are strongly recommended for a more robust assessment of the aerosol effects.« less

  14. Comprehensive Mapping and Characteristic Regimes of Aerosol Effects on the Formation and Evolution of Pyro-Convective Clouds

    SciTech Connect

    Chang, Di; Cheng, Yafang; Reutter, Philipp; Trentmann, Jrg; Burrows, Susannah M.; Spichtinger, Peter; Nordmann, Stephan; Andreae, M. O.; Poschl, U.; Su, Hang

    2015-09-21

    A recent parcel model study (Reutter et al., 2009) showed three deterministic regimes of initial cloud droplet formation characterized by ratios of aerosol concentrations (NCN) to updraft velocities. This analysis, however, did not reveal how these regimes evolve during the subsequent development of clouds. To address this issue, we employed the Active Tracer High Resolution Atmospheric Model with full microphysics and extended the model simulation from the cloud base to the entire column of a single pyro-convective mixed-phase cloud. A series of 2-D simulations (over 1000) were performed over a wide range of NCN and dynamic conditions. The integrated concentration of hydrometeors over the full spatial and temporal scales was used to evaluate the aerosol and dynamic effects. The results show that: (1) the three regimes for cloud condensation nuclei (CCN) activation in the parcel model (namely aerosol-limited, updraft-limited, and transitional regimes) still exist within our simulations, but the net production of raindrops and frozen particles occurs mostly within the updraft-limited regime. (2) Generally, elevated aerosols enhance the formation of cloud droplets and frozen particles. The response of raindrops and precipitation to aerosols is more complicated and can be either positive or negative as a function of aerosol concentrations. The most negative effect was found for a value of NCN of ~1000 to 3000 cm-3. (3) The employment of nonlinear (dynamic and microphysical) processes leads to a more complicated and unstable response of clouds to aerosol perturbation compared with the parcel model results. Therefore, conclusions drawn from limited case studies might require caveats regarding their representativeness, and high-resolution sensitivity studies over a wide range of aerosol concentrations and updraft velocities are highly recommended.

  15. Predictive models for water sources with high susceptibility for bromine-containing disinfection by-product formation: implications for water treatment.

    PubMed

    Watson, Kalinda; Farré, Maria José; Birt, James; McGree, James; Knight, Nicole

    2015-02-01

    This study examines a matrix of synthetic water samples designed to include conditions that favour brominated disinfection by-product (Br-DBP) formation, in order to provide predictive models suitable for high Br-DBP forming waters such as salinity-impacted waters. Br-DBPs are known to be more toxic than their chlorinated analogues, in general, and their formation may be favoured by routine water treatment practices such as coagulation/flocculation under specific conditions; therefore, circumstances surrounding their formation must be understood. The chosen factors were bromide concentration, mineral alkalinity, bromide to dissolved organic carbon (Br/DOC) ratio and Suwannee River natural organic matter concentration. The relationships between these parameters and DBP formation were evaluated by response surface modelling of data generated using a face-centred central composite experimental design. Predictive models for ten brominated and/or chlorinated DBPs are presented, as well as models for total trihalomethanes (tTHMs) and total dihaloacetonitriles (tDHANs), and bromide substitution factors for the THMs and DHANs classes. The relationships described revealed that increasing alkalinity and increasing Br/DOC ratio were associated with increasing bromination of THMs and DHANs, suggesting that DOC lowering treatment methods that do not also remove bromide such as enhanced coagulation may create optimal conditions for Br-DBP formation in waters in which bromide is present.

  16. Challenges of predicting the potential distribution of a slow-spreading invader: a habitat suitability map for an invasive riparian tree

    USGS Publications Warehouse

    Jarnevich, Catherine S.; Reynolds, Lindsay V.

    2011-01-01

    Understanding the potential spread of invasive species is essential for land managers to prevent their establishment and restore impacted habitat. Habitat suitability modeling provides a tool for researchers and managers to understand the potential extent of invasive species spread. Our goal was to use habitat suitability modeling to map potential habitat of the riparian plant invader, Russian olive (Elaeagnus angustifolia). Russian olive has invaded riparian habitat across North America and is continuing to expand its range. We compiled 11 disparate datasets for Russian olive presence locations (n = 1,051 points and 139 polygons) in the western US and used Maximum entropy (Maxent) modeling to develop two habitat suitability maps for Russian olive in the western United States: one with coarse-scale water data and one with fine-scale water data. Our models were able to accurately predict current suitable Russian olive habitat (Coarse model: training AUC = 0.938, test AUC = 0.907; Fine model: training AUC = 0.923, test AUC = 0.885). Distance to water was the most important predictor for Russian olive presence in our coarse-scale water model, but it was only the fifth most important variable in the fine-scale model, suggesting that when water bodies are considered on a fine scale, Russian olive does not necessarily rely on water. Our model predicted that Russian olive has suitable habitat further west from its current distribution, expanding into the west coast and central North America. Our methodology proves useful for identifying potential future areas of invasion. Model results may be influenced by locations of cultivated individuals and sampling bias. Further study is needed to examine the potential for Russian olive to invade beyond its current range. Habitat suitability modeling provides an essential tool for enhancing our understanding of invasive species spread.

  17. An assessment of the impact of the 2003 EPRI ground-motion prediction models on the USGS national seismic-hazard maps

    USGS Publications Warehouse

    Cramer, C.

    2006-01-01

    Ground-motion attenuation relations have an important impact on seismic hazard analyses. Ground-motion modeling is particularly sensitive to assumptions about wave-propagation attenuation (crustal Q and geometrical spreading), as well as source and site conditions. Studies of path attenuation from earthquakes in eastern North America (ENA) provide insights into the appropriateness of specific attenuation relations. An Electric Power Research Institute (EPRI) (2003, 2004) study combines published ENA ground-motion attenuation relations into four model forms: single-corner, double-corner, hybrid-empirical, and finite-fault. When substituted in the U.S. Geological Survey 2002 national seismic hazard maps for the five ENA relations originally used in those hazard calculations, the EPRI (2003) relations predict similar ground motions and hazard at short periods (0.5 sec), relative to the 2002 national maps. A major reason for this difference is due to the crustal seismic-wave attenuation model assumed in a few of the ENA relations combined into the EPRI (2003, 2004) models. Although appropriate differences in geometrical spreading models among ENA relations can also be significant, a few ENA relations have 1-Hz Q-values (Q0) that are below the EPRI (1993) consensus range for Q0 when coupled with a geometrical spreading of R-0.5. The EPRI (2003, 2004) single-corner relation is strongly influenced by the inclusion of ENA relations with assumed Q0 below the EPRI (1993) range, which explains much of the discrepancy in predictions at longer periods.

  18. Herschel/HIFI Spectral Mapping of C+, CH+, and CH in Orion BN/KL: The Prevailing Role of Ultraviolet Irradiation in CH+ Formation

    NASA Astrophysics Data System (ADS)

    Morris, Patrick W.; Gupta, Harshal; Nagy, Zsofia; Pearson, John C.; Ossenkopf-Okada, Volker; Falgarone, Edith; Lis, Dariusz C.; Gerin, Maryvonne; Melnick, Gary; Neufeld, David A.; Bergin, Edwin A.

    2016-09-01

    The CH+ ion is a key species in the initial steps of interstellar carbon chemistry. Its formation in diverse environments where it is observed is not well understood, however, because the main production pathway is so endothermic (4280 K) that it is unlikely to proceed at the typical temperatures of molecular clouds. We investigate the formation of this highly reactive molecule with the first velocity-resolved spectral mapping of the CH+ J = 1-0, 2-1 rotational transitions, three sets of CH Λ-doubled triplet lines, 12C+ and 13C+ {}2{P}3/2{{--}}2{P}1/2, and CH3OH 835 GHz E-symmetry Q-branch transitions, obtained with Herschel/HIFI over a region of ≈12 arcmin2 centered on the Orion BN/KL source. We present the spatial morphologies and kinematics, cloud boundary conditions, excitation temperatures, column densities, and 12C+ optical depths. Emission from all of C+, CH+, and CH is indicated to arise in the diluted gas, outside the explosive, dense BN/KL outflow. Our models show that UV irradiation provides favorable conditions for steady-state production of CH+ in this environment. Surprisingly, no spatial or kinematic correspondences of the observed species are found with H2 S(1) emission tracing shocked gas in the outflow. We propose that C+ is being consumed by rapid production of CO to explain the lack of both C+ and CH+ in the outflow. Hence, in star-forming environments containing sources of shocks and strong UV radiation, a description of the conditions leading to CH+ formation and excitation is incomplete without including the important—possibly dominant—role of UV irradiation.

  19. An evolutionary model-based algorithm for accurate phylogenetic breakpoint mapping and subtype prediction in HIV-1.

    PubMed

    Kosakovsky Pond, Sergei L; Posada, David; Stawiski, Eric; Chappey, Colombe; Poon, Art F Y; Hughes, Gareth; Fearnhill, Esther; Gravenor, Mike B; Leigh Brown, Andrew J; Frost, Simon D W

    2009-11-01

    Genetically diverse pathogens (such as Human Immunodeficiency virus type 1, HIV-1) are frequently stratified into phylogenetically or immunologically defined subtypes for classification purposes. Computational identification of such subtypes is helpful in surveillance, epidemiological analysis and detection of novel variants, e.g., circulating recombinant forms in HIV-1. A number of conceptually and technically different techniques have been proposed for determining the subtype of a query sequence, but there is not a universally optimal approach. We present a model-based phylogenetic method for automatically subtyping an HIV-1 (or other viral or bacterial) sequence, mapping the location of breakpoints and assigning parental sequences in recombinant strains as well as computing confidence levels for the inferred quantities. Our Subtype Classification Using Evolutionary ALgorithms (SCUEAL) procedure is shown to perform very well in a variety of simulation scenarios, runs in parallel when multiple sequences are being screened, and matches or exceeds the performance of existing approaches on typical empirical cases. We applied SCUEAL to all available polymerase (pol) sequences from two large databases, the Stanford Drug Resistance database and the UK HIV Drug Resistance Database. Comparing with subtypes which had previously been assigned revealed that a minor but substantial (approximately 5%) fraction of pure subtype sequences may in fact be within- or inter-subtype recombinants. A free implementation of SCUEAL is provided as a module for the HyPhy package and the Datamonkey web server. Our method is especially useful when an accurate automatic classification of an unknown strain is desired, and is positioned to complement and extend faster but less accurate methods. Given the increasingly frequent use of HIV subtype information in studies focusing on the effect of subtype on treatment, clinical outcome, pathogenicity and vaccine design, the importance of accurate

  20. Mineralogical Mapping of the Banded Iron Formations using Fourier Transform Infra-Red (FTIR) Spectroscopy and micro-Raman Spectroscopy

    NASA Astrophysics Data System (ADS)

    McKeeby, B. E.; Schoonen, M. A.; Glotch, T. D.; Ohmoto, H.

    2013-12-01

    Banded Iron Formations (BIFs) consist of thin alternating layers of iron-poor silica and iron-bearing phylosilicates, iron oxides, and carbonates and/or sulfides. BIFs are common in the Precambrian. Although BIFs have been the subject of numerous studies, the mechanism and environments of formation remains poorly understood. It has been hotly debated whether BIFs formed by microbes in Fe2+-rich oceans under a reducing atmosphere, or by reactions between locally discharged submarine hydrothermal fluids and O2-rich deep ocean water. The debates have continued mostly because of the lack of detailed studies on the paragenesis of minerals in BIFs to determine which minerals are primary precipitates, and which are diagenetic and metamorphic products. The purpose of this study is to explore the applications of FTIR spectroscopy and micro-Raman spectroscopy in micro-scale paragenetic studies of BIF samples. FTIR and Raman are vibrational spectroscopy techniques that provide insight into the chemical bonding within a compound. With these techniques it is possible to resolve the iron oxide, carbonate, and clay mineralogy within BIFs, which is difficult with techniques that rely on elemental analysis, such as TEM-EDAX. Samples used in this study are thin sections of the 2.7 Ga BIFs from Temagami in the Abitibi green stone belt, Ontario, Canada. FTIR analyses were conducted using a Nicolet iN10MX Micro-Imaging FTIR Spectrometer. This instrument is capable of collecting hyperspectral infrared images with a pixel size of 25 microns covering the range from 7000 to 715 cm-1. In addition, we collected point spectra measuring 50X50 microns over a spectral range from 4000 to 400 cm-1. These point spectra were used to distinguish among different iron minerals in the thin sections. Using the hyperspectral data, we created composite false color Images to show mineral variation across the samples. The spectra were modeled using a digital spectral library. After modeling and examination

  1. Mapping the heparin-binding site of the BMP antagonist gremlin by site-directed mutagenesis based on predictive modelling.

    PubMed

    Tatsinkam, Arnold Junior; Mulloy, Barbara; Rider, Christopher C

    2015-08-15

    Gremlin is a member of the CAN (cerberus and DAN) family of secreted BMP (bone morphogenetic protein) antagonists and also an agonist of VEGF (vascular endothelial growth factor) receptor-2. It is critical in limb skeleton and kidney development and is re-expressed during tissue fibrosis. Gremlin binds strongly to heparin and heparan sulfate and, in the present study, we sought to investigate its heparin-binding site. In order to explore a putative non-contiguous binding site predicted by computational molecular modelling, we substituted a total of 11 key arginines and lysines located in three basic residue sequence clusters with homologous sequences from cerberus and DAN (differential screening selected gene abberative in neuroblastoma), CAN proteins which lack basic residues in these positions. A panel of six Myc-tagged gremlin mutants, MGR-1-MGR-6 (MGR, mutant gremlin), each containing different combinations of targeted substitutions, all showed markedly reduced affinity for heparin as demonstrated by their NaCl elution on heparin affinity chromatography, thus verifying our predictions. Both MGR-5 and MGR-6 retained BMP-4-binding activity comparable to that of wild-type gremlin. Low-molecular-mass heparin neither promoted nor inhibited BMP-4 binding. Finally, glutaraldehyde cross-linking demonstrated that gremlin forms non-covalent dimers, similar behaviour to that of DAN and also PRDC (protein related to cerberus and DAN), another CAN protein. The resulting dimer would possess two heparin-binding sites, each running along an exposed surface on the second β-strand finger loop of one of the monomers.

  2. Global Mapping Project - Applications and Development of Version 2 Dataset

    NASA Astrophysics Data System (ADS)

    Ubukawa, T.; Nakamura, T.; Otsuka, T.; Iimura, T.; Kishimoto, N.; Nakaminami, K.; Motojima, Y.; Suga, M.; Yatabe, Y.; Koarai, M.; Okatani, T.

    2012-07-01

    The Global Mapping Project aims to develop basic geospatial information of the whole land area of the globe, named Global Map, through the cooperation of National Mapping Organizations (NMOs) around the world. The Global Map data can be a base of global geospatial infrastructure and is composed of eight layers: Boundaries, Drainage, Transportation, Population Centers, Elevation, Land Use, Land Cover and Vegetation. The Global Map Version 1 was released in 2008, and the Version 2 will be released in 2013 as the data are to be updated every five years. In 2009, the International Steering Committee for Global Mapping (ISCGM) adopted new Specifications to develop the Global Map Version 2 with a change of its format so that it is compatible with the international standards, namely ISO 19136 and ISO 19115. With the support of the secretariat of ISCGM, the project participating countries are accelerating their data development toward the completion of the global coverage in 2013, while some countries have already released their Global Map version 2 datasets since 2010. Global Map data are available from the Internet free of charge for non-commercial purposes, which can be used to predict, assess, prepare for and cope with global issues by combining with other spatial data. There are a lot of Global Map applications in various fields, and further utilization of Global Map is expected. This paper summarises the activities toward the development of the Global Map Version 2 as well as some examples of the Global Map applications in various fields.

  3. Real Time Monitoring of Dissolved Organic Carbon Concentration and Disinfection By-Product Formation Potential in a Surface Water Treatment Plant with Simulaneous UV-VIS Absorbance and Fluorescence Excitation-Emission Mapping

    NASA Astrophysics Data System (ADS)

    Gilmore, A. M.

    2015-12-01

    This study describes a method based on simultaneous absorbance and fluorescence excitation-emission mapping for rapidly and accurately monitoring dissolved organic carbon concentration and disinfection by-product formation potential for surface water sourced drinking water treatment. The method enables real-time monitoring of the Dissolved Organic Carbon (DOC), absorbance at 254 nm (UVA), the Specific UV Absorbance (SUVA) as well as the Simulated Distribution System Trihalomethane (THM) Formation Potential (SDS-THMFP) for the source and treated water among other component parameters. The method primarily involves Parallel Factor Analysis (PARAFAC) decomposition of the high and lower molecular weight humic and fulvic organic component concentrations. The DOC calibration method involves calculating a single slope factor (with the intercept fixed at 0 mg/l) by linear regression for the UVA divided by the ratio of the high and low molecular weight component concentrations. This method thus corrects for the changes in the molecular weight component composition as a function of the source water composition and coagulation treatment effects. The SDS-THMFP calibration involves a multiple linear regression of the DOC, organic component ratio, chlorine residual, pH and alkalinity. Both the DOC and SDS-THMFP correlations over a period of 18 months exhibited adjusted correlation coefficients with r2 > 0.969. The parameters can be reported as a function of compliance rules associated with required % removals of DOC (as a function of alkalinity) and predicted maximum contaminant levels (MCL) of THMs. The single instrument method, which is compatible with continuous flow monitoring or grab sampling, provides a rapid (2-3 minute) and precise indicator of drinking water disinfectant treatability without the need for separate UV photometric and DOC meter measurements or independent THM determinations.

  4. National Atlas maps

    USGS Publications Warehouse

    ,

    1991-01-01

    The National Atlas of the United States of America was published by the U.S. Geological Survey in 1970. Its 765 maps and charts are on 335 14- by 19-inch pages. Many of the maps span facing pages. It's worth a quick trip to the library just to leaf through all 335 pages of this book. Rapid scanning of its thematic maps yields rich insights to the geography of issues of continuing national interest. On most maps, the geographic patterns are still valid, though the data are not current. The atlas is out of print, but many of its maps can be purchased separately. Maps that span facing pages in the atlas are printed on one sheet. The maps dated after 1970 are either revisions of original atlas maps, or new maps published in atlas format. The titles of the separate maps are listed here.

  5. easyPAC: A Tool for Fast Prediction, Testing and Reference Mapping of Degenerate PCR Primers from Alignments or Consensus Sequences

    PubMed Central

    Rosenkranz, David

    2012-01-01

    The PCR-amplification of unknown homologous or paralogous genes generally relies on PCR primers predicted from multi sequence alignments. But increasing sequence divergence can induce the need to use degenerate primers which entails the problem of testing the characteristics, unwanted interactions and potential mispriming of degenerate primers. Here I introduce easyPAC, a new software for the prediction of degenerate primers from multi sequence alignments or single consensus sequences. As a major innovation, easyPAC allows to apply all customary primer test procedures to degenerate primer sequences including fast mapping to reference files. Thus, easyPAC simplifies and expedites the designing of specific degenerate primers enormously. Degenerate primers suggested by easyPAC were used in PCR amplification with subsequent de novo sequencing of TDRD1 exon 11 homologs from several representatives of the haplorrhine primate phylogeny. The results demonstrate the efficient performance of the suggested primers and therefore show that easyPAC can advance upcoming comparative genetic studies.

  6. Self-Organizing Map (SOM) and Support Vector Machine (SVM) Models for the Prediction of Human Epidermal Growth Factor Receptor (EGFR/ ErbB-1) Inhibitors.

    PubMed

    Kong, Yue; Qu, Dan; Chen, Xiaoyan; Gong, Ya-Nan; Yan, Aixia

    2016-01-01

    EGFR (ErbB-1/HER1) kinase plays an important role in cancer therapy. Two classification models were established to predict whether a compound is an inhibitor or a decoy of human EGFR (ErbR-1) by using Kohonen's self-organizing map (SOM) and support vector machine (SVM). A dataset containing 1248 ATP binding site inhibitors and 3090 decoys was collected and randomly divided into a training set (831 inhibitors and 2064 decoys) and a test set (417 inhibitors and 1029 decoys). The descriptors that represent molecular structures were calculated by software ADRIANA.Code. Thirteen significant descriptors including five global descriptors and eight 2D property autocorrelation descriptors were selected by Pearson correlation analysis and stepwise analysis. The prediction accuracies on training set and test set are 98.5% and 96.3% for SOM model, 99.0% and 97.0% for SVM model, respectively. Both of these two classification models have good performance on distinguishing EGFR inhibitors from decoys. PMID:27074760

  7. The distribution of bioluminescence and chlorophyll during the late summer in the North Atlantic: Maps and a predictive model

    NASA Astrophysics Data System (ADS)

    Ondercin, Daniel G.; Atkinson, Charles A.; Kiefer, Dale A.

    1995-04-01

    During August 1991 an instrument array (the Paravane) was towed continuously for several days over long distances in the North Atlantic and around the Marine Light-Mixed Layer (MLML) mooring (60°N, 21°W). Among other sensors, the Paravane carried a thermistor, a fluorometer that measured the fluorescence emitted by chlorophyll a, a bathyphotometer that measured stimulable bioluminescence, and a beam transmissometer that measured the volume attenuation coefficient at 490 nm. The record of these biooptical measurements provides a detailed description of the upper 150 m of the water column as well as of diel variability. An examination of the transects, which covered a latitudinal range from 43°N to 60°N and a longitudinal range from 13°W to 54°W, indicates that in the colder and more northerly waters most of the chlorophyll a, attenuation, and bioluminescence were found within the surface mixed layer. In the warmer waters to the south, there were subsurface maxima for all three parameters. We have used the Paravane records to test a model that provides predictions of the vertical distribution of chlorophyll a, bioluminescence, and beam attenuation from oceanographie parameters that characterize the surface mixed layer: temperature, chlorophyll a concentration, irradiance incident to the sea surface, mixed layer depth, and nitrate concentration. The first three parameters can be measured from sensors aboard satellites while the last two parameters can be obtained from oceanographie databases. The model is based upon a description of the acclimation of the phytoplankton, an assumption about the vertical distribution of phytoplankton within the euphotic zone, and an empirical description of the relationship between bioluminescence, light intensity, and phytoplankton concentration.

  8. Support vector regression-guided unravelling: antioxidant capacity and quantitative structure-activity relationship predict reduction and promotion effects of flavonoids on acrylamide formation

    NASA Astrophysics Data System (ADS)

    Huang, Mengmeng; Wei, Yan; Wang, Jun; Zhang, Yu

    2016-09-01

    We used the support vector regression (SVR) approach to predict and unravel reduction/promotion effect of characteristic flavonoids on the acrylamide formation under a low-moisture Maillard reaction system. Results demonstrated the reduction/promotion effects by flavonoids at addition levels of 1–10000 μmol/L. The maximal inhibition rates (51.7%, 68.8% and 26.1%) and promote rates (57.7%, 178.8% and 27.5%) caused by flavones, flavonols and isoflavones were observed at addition levels of 100 μmol/L and 10000 μmol/L, respectively. The reduction/promotion effects were closely related to the change of trolox equivalent antioxidant capacity (ΔTEAC) and well predicted by triple ΔTEAC measurements via SVR models (R: 0.633–0.900). Flavonols exhibit stronger effects on the acrylamide formation than flavones and isoflavones as well as their O-glycosides derivatives, which may be attributed to the number and position of phenolic and 3-enolic hydroxyls. The reduction/promotion effects were well predicted by using optimized quantitative structure-activity relationship (QSAR) descriptors and SVR models (R: 0.926–0.994). Compared to artificial neural network and multi-linear regression models, SVR models exhibited better fitting performance for both TEAC-dependent and QSAR descriptor-dependent predicting work. These observations demonstrated that the SVR models are competent for predicting our understanding on the future use of natural antioxidants for decreasing the acrylamide formation.

  9. Support vector regression-guided unravelling: antioxidant capacity and quantitative structure-activity relationship predict reduction and promotion effects of flavonoids on acrylamide formation

    PubMed Central

    Huang, Mengmeng; Wei, Yan; Wang, Jun; Zhang, Yu

    2016-01-01

    We used the support vector regression (SVR) approach to predict and unravel reduction/promotion effect of characteristic flavonoids on the acrylamide formation under a low-moisture Maillard reaction system. Results demonstrated the reduction/promotion effects by flavonoids at addition levels of 1–10000 μmol/L. The maximal inhibition rates (51.7%, 68.8% and 26.1%) and promote rates (57.7%, 178.8% and 27.5%) caused by flavones, flavonols and isoflavones were observed at addition levels of 100 μmol/L and 10000 μmol/L, respectively. The reduction/promotion effects were closely related to the change of trolox equivalent antioxidant capacity (ΔTEAC) and well predicted by triple ΔTEAC measurements via SVR models (R: 0.633–0.900). Flavonols exhibit stronger effects on the acrylamide formation than flavones and isoflavones as well as their O-glycosides derivatives, which may be attributed to the number and position of phenolic and 3-enolic hydroxyls. The reduction/promotion effects were well predicted by using optimized quantitative structure-activity relationship (QSAR) descriptors and SVR models (R: 0.926–0.994). Compared to artificial neural network and multi-linear regression models, SVR models exhibited better fitting performance for both TEAC-dependent and QSAR descriptor-dependent predicting work. These observations demonstrated that the SVR models are competent for predicting our understanding on the future use of natural antioxidants for decreasing the acrylamide formation. PMID:27586851

  10. Support vector regression-guided unravelling: antioxidant capacity and quantitative structure-activity relationship predict reduction and promotion effects of flavonoids on acrylamide formation.

    PubMed

    Huang, Mengmeng; Wei, Yan; Wang, Jun; Zhang, Yu

    2016-01-01

    We used the support vector regression (SVR) approach to predict and unravel reduction/promotion effect of characteristic flavonoids on the acrylamide formation under a low-moisture Maillard reaction system. Results demonstrated the reduction/promotion effects by flavonoids at addition levels of 1-10000 μmol/L. The maximal inhibition rates (51.7%, 68.8% and 26.1%) and promote rates (57.7%, 178.8% and 27.5%) caused by flavones, flavonols and isoflavones were observed at addition levels of 100 μmol/L and 10000 μmol/L, respectively. The reduction/promotion effects were closely related to the change of trolox equivalent antioxidant capacity (ΔTEAC) and well predicted by triple ΔTEAC measurements via SVR models (R: 0.633-0.900). Flavonols exhibit stronger effects on the acrylamide formation than flavones and isoflavones as well as their O-glycosides derivatives, which may be attributed to the number and position of phenolic and 3-enolic hydroxyls. The reduction/promotion effects were well predicted by using optimized quantitative structure-activity relationship (QSAR) descriptors and SVR models (R: 0.926-0.994). Compared to artificial neural network and multi-linear regression models, SVR models exhibited better fitting performance for both TEAC-dependent and QSAR descriptor-dependent predicting work. These observations demonstrated that the SVR models are competent for predicting our understanding on the future use of natural antioxidants for decreasing the acrylamide formation. PMID:27586851

  11. Support vector regression-guided unravelling: antioxidant capacity and quantitative structure-activity relationship predict reduction and promotion effects of flavonoids on acrylamide formation.

    PubMed

    Huang, Mengmeng; Wei, Yan; Wang, Jun; Zhang, Yu

    2016-09-02

    We used the support vector regression (SVR) approach to predict and unravel reduction/promotion effect of characteristic flavonoids on the acrylamide formation under a low-moisture Maillard reaction system. Results demonstrated the reduction/promotion effects by flavonoids at addition levels of 1-10000 μmol/L. The maximal inhibition rates (51.7%, 68.8% and 26.1%) and promote rates (57.7%, 178.8% and 27.5%) caused by flavones, flavonols and isoflavones were observed at addition levels of 100 μmol/L and 10000 μmol/L, respectively. The reduction/promotion effects were closely related to the change of trolox equivalent antioxidant capacity (ΔTEAC) and well predicted by triple ΔTEAC measurements via SVR models (R: 0.633-0.900). Flavonols exhibit stronger effects on the acrylamide formation than flavones and isoflavones as well as their O-glycosides derivatives, which may be attributed to the number and position of phenolic and 3-enolic hydroxyls. The reduction/promotion effects were well predicted by using optimized quantitative structure-activity relationship (QSAR) descriptors and SVR models (R: 0.926-0.994). Compared to artificial neural network and multi-linear regression models, SVR models exhibited better fitting performance for both TEAC-dependent and QSAR descriptor-dependent predicting work. These observations demonstrated that the SVR models are competent for predicting our understanding on the future use of natural antioxidants for decreasing the acrylamide formation.

  12. Mapping gas-phase organic reactivity and concomitant secondary organic aerosol formation: chemometric dimension reduction techniques for the deconvolution of complex atmospheric data sets

    NASA Astrophysics Data System (ADS)

    Wyche, K. P.; Monks, P. S.; Smallbone, K. L.; Hamilton, J. F.; Alfarra, M. R.; Rickard, A. R.; McFiggans, G. B.; Jenkin, M. E.; Bloss, W. J.; Ryan, A. C.; Hewitt, C. N.; MacKenzie, A. R.

    2015-07-01

    Highly non-linear dynamical systems, such as those found in atmospheric chemistry, necessitate hierarchical approaches to both experiment and modelling in order to ultimately identify and achieve fundamental process-understanding in the full open system. Atmospheric simulation chambers comprise an intermediate in complexity, between a classical laboratory experiment and the full, ambient system. As such, they can generate large volumes of difficult-to-interpret data. Here we describe and implement a chemometric dimension reduction methodology for the deconvolution and interpretation of complex gas- and particle-phase composition spectra. The methodology comprises principal component analysis (PCA), hierarchical cluster analysis (HCA) and positive least-squares discriminant analysis (PLS-DA). These methods are, for the first time, applied to simultaneous gas- and particle-phase composition data obtained from a comprehensive series of environmental simulation chamber experiments focused on biogenic volatile organic compound (BVOC) photooxidation and associated secondary organic aerosol (SOA) formation. We primarily investigated the biogenic SOA precursors isoprene, α-pinene, limonene, myrcene, linalool and β-caryophyllene. The chemometric analysis is used to classify the oxidation systems and resultant SOA according to the controlling chemistry and the products formed. Results show that "model" biogenic oxidative systems can be successfully separated and classified according to their oxidation products. Furthermore, a holistic view of results obtained across both the gas- and particle-phases shows the different SOA formation chemistry, initiating in the gas-phase, proceeding to govern the differences between the various BVOC SOA compositions. The results obtained are used to describe the particle composition in the context of the oxidised gas-phase matrix. An extension of the technique, which incorporates into the statistical models data from anthropogenic (i

  13. Spatial mapping takes time.

    PubMed

    Whishaw, I Q

    1998-01-01

    The experiment tested the prediction that spatial mapping takes time and asked whether time use is reflected in the overt behavior of a performing animal. The study examines this question by exploiting the expected behavioral differences of control rats and rats with hippocampal formation damage induced with fimbria-fornix (FF) lesions on a spatial navigation task. Previous studies have shown that control rats use a mapping strategy, in which they use the relative positions of environmental cues to reach places in space, whereas FF rats use a cue-based strategy, in which they are guided by a single cue or their own body orientation. Therefore, control and FF rats were overtrained on a complex foraging task in which they left a burrow to retrieve eight food pellets hidden around the perimeter of a circular table. The control rats retrieved the food pellets in order of their distance from the burrow, took direct routes to the food, and made few errors, all of which suggested they used a spatial strategy. The FF rats were less likely to retrieve food as a function of its distance, took a circular path around the perimeter of the table, and made many errors, suggesting they used a cue-based strategy. Despite taking shorter routes than the FF rats, the control rats had proportionally slower response speeds. Their slow response speeds support the hypothesis that spatial mapping takes time and that mapping time is reflected in behavior. The results are discussed in relation to their relevance to spatial mapping theory, hippocampal function, and the evolution of foraging strategies.

  14. Mapping the Frozen Void

    NASA Astrophysics Data System (ADS)

    Suutarinen, Aleksi; Fraser, Helen

    2013-07-01

    Reactions on the surfaces of dust grains play a vital role in the overall chemistry of interstellar matter. These grains become covered by icy layers, which are the largest molecular reservoir in the interstellar medium. Given this, it is surprising that the effect ice has on the overall chain of reactions is poorly characterized. One step on the path of gaining better understanding here is to develop methods of figuring out how much ice is present in these clouds, the links between ice components, and synergy between the ices and gas phase molecules. We do this by examining the absorption spectra of ices on lines of sight towards several stars behind clouds of interstellar matter. From these we can reconstruct spatial maps of the ice distribution on scales of as little as 1000 AU, as a test of the chemical variation within a cloud. By overlapping the ice data with other maps of the same region (gas emission, temperature, density etc) we create combined maps to reveal the astrochemistry of star-forming regions and pre-stellar cores. In this poster we present the continuing results of our ice mapping programme, using data from the AKARI satellite, specifically in slitless spectroscopy observations in the NIR. In this region the key ice features encompass H2O, CO and CO2. The maps illustrate the power of our dedicated AKARI data reduction pipeline, and the novelty of our observing programme. We also detail the next steps' in our ice mapping research. The method is being expanded to include the full 10'x10' AKARI field of view, taking account of image distortion induced by the dispersing optics. These maps are then combined with exiting gas-phase observations and SCUBA maps. The latest attempts at this are shown here. What is clear already is that it is difficult to predict ice abundances from factors such as extinction or gas density alone, and that ice formation and evolution can vary hugely over even very small astronomical scales.

  15. Maps showing coal-split boundaries, isopachs of coal splits, coal resources, and coal quality; Mammoth coal bed, Paleocene Tongue River Member of the Fort Union Formation, Bull Mountain coal field, south-central Montana

    SciTech Connect

    Connor, C.W.

    1989-01-01

    A U.S. Geological Survey Maps are presented showing coal-split boundaries, isopachs of coal splits, coal resources, and coal quality; mammoth coal bed, Paleocene Tongue River Member of the Fort Union Formation, Bull Mountain coal field, south-central Montana.

  16. Epoxide pathways improve model predictions of isoprene markers and reveal key role of acidity in aerosol formation

    EPA Science Inventory

    Isoprene significantly contributes to organic aerosol in the southeastern United States where biogenic hydrocarbons mix with anthropogenic emissions. In this work, the Community Multiscale Air Quality model is updated to predict isoprene aerosol from epoxides produced under both ...

  17. Fusion Geographic Information System Data with State-of-the-art Atmospheric Systems: Application to Methane Source Mapping over the Marcellus Shale formation

    NASA Astrophysics Data System (ADS)

    Cao, Y.; Barkley, Z.; Cervone, G.; Lauvaux, T.; Deng, A.; Sarmiento, D. P.

    2015-12-01

    Natural gas production from multiple shale formations has increased significantly in the last decade. More particularly, a growing number of unconventional wells is the result of intense drilling in the Marcellus shale area. The Marcellus shale production represents a third of the production of natural gas in the entire US. This unprecedented increase could lead to additional fugitive methane (CH4) emissions at a level that remains highly uncertain. If natural gas is to replace less energy-efficient fossil fuels, the emissions during the production phase ought to be relatively small. However, the magnitude and the spatial distribution of CH4 emissions from unconventional wells in the Marcellus shale remains poorly documented. The novelty of this research consists in coupling various sources of information to map accurately the methane emissions, combining Geographical Information System (GIS) data, atmospheric measurements of greenhouse gases, and atmospheric modeling tools. We first collected various GIS data to estimate CH4 emissions caused by the shale gas industry, such as wells, facilities, and pipelines, with the other major contributors such as wetlands, farming activities, and soils. We present our projection methods to generate model input in gridded format while preserving the distribution and magnitude of the emissions and assembling a diverse database. The projection tools for GIS data are generalized to the use of GIS data in atmospheric modeling systems. We then present the atmospheric concentrations simulated by the Weather Research and Forecast (WRF) model, used to represent the transport and the dispersion of CH4 emissions. We compare the WRF model results to aircraft measurements collected during a 3-week campaign to identify missing sources in our initial inventory. We finally propose a new approach to identify the area at the surface that could potentially influence the aircraft measurements using spatial analysis of particle footprints. This

  18. Sinkhole Precursors and Formation Mechanism along the Dead Sea Shorelines, Israel, Analyzed by InSAR, Field Mapping, Water Analysis and Elastic Modeling

    NASA Astrophysics Data System (ADS)

    Nof, R. N.; Baer, G.; Avni, Y.; Shviro, M.; Atzori, S.

    2014-12-01

    The water level of the Dead Sea (Israel and Jordan) has been dropping at an increasing rate since the 1960s, exceeding a meter per year during the last decade. This water-level drop has triggered the formation of sinkholes and land subsidence along the Dead Sea shorelines, resulting in severe economic loss and infrastructural damage. We demonstrate the use of Interferometric Synthetic Aperture Radar (InSAR) measurements from COSMO-SkyMed images, combined with an airborne Light Detection and Ranging (LiDAR) Digital Elevation Model to detect sinkhole-related subsidence. In several locations, precursory subsidence tens to more than a hundred meters wide, at rates between 0.5 and 2 mm/day started a few months to more than a year before an actual collapse of a sinkhole. The sinkholes, a few meters wide and up to 25 m deep, form generally at the perimeter of the subsiding areas. By means of a simplified model representing a distributed closure of a sill-like crack, we estimate the cavity volume occupied by the subsiding sedimentary overburden and explain the spatial relationships between the gradual surface subsidence and the sinkholes. The subsiding areas and successive sinkholes in a specific site migrate laterally, possibly due to progressive dissolution and widening of the underlying cavities. Combining InSAR measurements with sinkhole mapping and chemical and isotopic analyses of groundwater and surface water, we find a new mode of sinkhole formation. The sinkholes initiate by dissolution of a 10-20 m deep and 5-15 m thick halite layer by fresh groundwater. The process continues and accelerates as flash-floods are drained by existing or by newly formed sinkholes, the subsurface salt layer dissolves rapidly, the overlying ground subsides, and salt-saturated water seeps out downstream of the draining sinkholes. The number of sinkholes and the rates and dimensions of subsidence increase significantly during and immediately after the flood events, and decay

  19. Design study of the geometry of the blanking tool to predict the burr formation of Zircaloy-4 sheet

    NASA Astrophysics Data System (ADS)

    Ha, Jisun; Lee, Hyungyil; Kim, Dongchul; Kim, Naksoo

    2013-12-01

    In this work, we investigated factors that influence burr formation for zircaloy-4 sheet used for spacer grids of nuclear fuel roads. Factors we considered are geometric factors of punch. We changed clearance and velocity in order to consider the failure parameters, and we changed shearing angle and corner radius of L-shaped punch in order to consider geometric factors of punch. First, we carried out blanking test with failure parameter of GTN model using L-shaped punch. The tendency of failure parameters and geometric factors that affect burr formation by analyzing sheared edges is investigated. Consequently, geometric factor's influencing on the burr formation is also high as failure parameters. Then, the sheared edges and burr formation with failure parameters and geometric factors is investigated using FE analysis model. As a result of analyzing sheared edges with the variables, we checked geometric factors more affect burr formation than failure parameters. To check the reliability of the FE model, the blanking force and the sheared edges obtained from experiments are compared with the computations considering heat transfer.

  20. Predictive-like distribution mapping using Google Earth: reassessment of the distribution of the bromeligenous frog, Scinax v-signatus (Anura: Hylidae).

    PubMed

    Da Silva, Helio Ricardo; Alves-Silva, Ricardo

    2013-01-01

    The hylid frog Scinax perpusillus species group comprises 13 species that share, in addition to a few morphological features, reproduction that occurs exclusively associated with bromeliads. Among the species in the group, Scinax v-signatus (Lutz, 1968) is one of the few with a relatively large geographic distribution, occurring in association with bromeliads growing on granitic outcrops above 800 m along the Serra dos Órgãos (a local designation of Serra do Mar) in the Atlantic forest, State of Rio de Janeiro. Here we demonstrate that previous assessment of the distribution of this species was overestimated, and reevaluate the available data on its occurrence. The distributional data analyzed was based on three levels of evidence. First, we assessed the distribution of the bromeliad, Alcantarea imperialis (Carrière) Harms, which is used by S. v-signatus at the type locality. We plotted potential occurrence data for this plant using Google Earth (GE) by visually inspecting GE images in search of indications of granitic outcrops where groups and large individual bromeliads could be identified. Second, we plotted the distribution of these plants and that of the frog based on locality data taken from the literature and voucher specimens in natural history collections and checked for congruence between these sets of data. Third, as a second test of accuracy of this methodology we visited four new localities indicated by the bromeliad-occurrence GE prediction map and searched for the occurrence of both the frog and the bromeliad. This simple process has proven efficient and accurate in finding new collecting sites and determining the distribution of the two involved taxa. We discuss this and other possibilities of using Google Earth as a tool for mapping and discovering the distribution of organisms and habitats. Furthermore, this study has shed light on a more accurate and realistic estimate of the distribution of Scinax v-signatus with implications for the

  1. Identification of Phosphoinositide-Binding Protein PATELLIN2 as a Substrate of Arabidopsis MPK4 MAP Kinase during Septum Formation in Cytokinesis

    PubMed Central

    Suzuki, Takamasa; Matsushima, Chiyuki; Nishimura, Shingo; Higashiyama, Tetsuya; Sasabe, Michiko; Machida, Yasunori

    2016-01-01

    The phosphorylation of proteins by protein kinases controls many cellular and physiological processes, which include intracellular signal transduction. However, the underlying molecular mechanisms of such controls and numerous substrates of protein kinases remain to be characterized. The mitogen-activated protein kinase (MAPK) cascade is of particular importance in a variety of extracellular and intracellular signaling processes. In plant cells, the progression of cytokinesis is an excellent example of an intracellular phenomenon that requires the MAPK cascade. However, the way in which MAPKs control downstream processes during cytokinesis in plant cells remains to be fully determined. We show here that comparisons, by two-dimensional difference gel electrophoresis, of phosphorylated proteins from wild-type Arabidopsis thaliana and mutant plants defective in a MAPK cascade allow identification of substrates of a specific MAPK. Using this method, we identified the PATELLIN2 (PATL2) protein, which has a SEC14 domain, as a substrate of MPK4 MAP kinase. PATL2 was concentrated at the cell division plane, as is MPK4, and had binding affinity for phosphoinositides. This binding affinity was altered after phosphorylation of PATL2 by MPK4, suggesting a role for the MAPK cascade in the formation of cell plates via regeneration of membranes during cytokinesis. PMID:27335345

  2. Hybrid Equation/Agent-Based Model of Ischemia-Induced Hyperemia and Pressure Ulcer Formation Predicts Greater Propensity to Ulcerate in Subjects with Spinal Cord Injury

    PubMed Central

    Solovyev, Alexey; Mi, Qi; Tzen, Yi-Ting; Brienza, David; Vodovotz, Yoram

    2013-01-01

    Pressure ulcers are costly and life-threatening complications for people with spinal cord injury (SCI). People with SCI also exhibit differential blood flow properties in non-ulcerated skin. We hypothesized that a computer simulation of the pressure ulcer formation process, informed by data regarding skin blood flow and reactive hyperemia in response to pressure, could provide insights into the pathogenesis and effective treatment of post-SCI pressure ulcers. Agent-Based Models (ABM) are useful in settings such as pressure ulcers, in which spatial realism is important. Ordinary Differential Equation-based (ODE) models are useful when modeling physiological phenomena such as reactive hyperemia. Accordingly, we constructed a hybrid model that combines ODEs related to blood flow along with an ABM of skin injury, inflammation, and ulcer formation. The relationship between pressure and the course of ulcer formation, as well as several other important characteristic patterns of pressure ulcer formation, was demonstrated in this model. The ODE portion of this model was calibrated to data related to blood flow following experimental pressure responses in non-injured human subjects or to data from people with SCI. This model predicted a higher propensity to form ulcers in response to pressure in people with SCI vs. non-injured control subjects, and thus may serve as novel diagnostic platform for post-SCI ulcer formation. PMID:23696726

  3. A kinetic mechanism for predicting secondary aerosol formation from the reactions of d-limonene in the presence of oxides of nitrogen and natural sunlight

    NASA Astrophysics Data System (ADS)

    Leungsakul, Sirakarn; Jeffries, Harvey E.; Kamens, Richard M.

    Among the monoterpenes, d-limonene is one of the most reactive, and has one of the highest particle formation potentials. Chamber experiments with d-limonene, nitric oxide, nitrogen dioxide, and diurnal natural sunlight are compared with simulation results from a first generation semi-explicit d-limonene daytime mechanism. The d-limonene model adequately predicts the timing of NO-NO 2 crossover, d-limonene decay, and the general trend of ozone formation, and particle mass accumulation. When experimental secondary organic aerosol (SOA) masses were greater than 1 mg m -3 the simulations tended to agree closely with the measured aerosol maxima. At lower SOA concentrations, the simulations tended to overpredict measured aerosol maxima by 25-50%. FTIR analysis and GC-ECD measurements indicate particle phase nitrates and peroxyacetyl nitrate (PAN) formation in the system. In the afternoon when temperatures are highest in the outdoor chambers, the slow rise of continuous ozone measurements suggests that PAN type compounds were decomposing to "bleed" NO 2 into the gas phase. Partitioning calculations also suggest that these types of compounds are off-gassing from the particle phase later in the afternoon as well, and provide an additional source of NO 2. Predicted aerosol yields with a commonly used two-parameter aerosol yield model are compared with experimental aerosol yields. The parameritized aerosol yield model had difficulty predicting most of the UNC chamber data. The explicit d-limonene mechanism developed in this study could reasonably simulate the aerosol formation trend in the Caltech chambers, but tended to overpredict SOA maxima.

  4. Mapping "old" versus "young" piñon-juniper stands with a predictive topo-climatic model in north-central New Mexico, USA

    USGS Publications Warehouse

    Jacobs, B. F.; Romme, W.H.; Allen, C. D.

    2008-01-01

    Piñon pine and juniper woodlands in the southwestern United States are often represented as an expanding and even invasive vegetation type, a legacy of historic grazing, and culpable in the degradation of western rangelands. A long-standing emphasis on forage production, in combination with recent hazard fuel concerns, has prompted a new era of woodland management with stated restoration objectives. Yet the extent and dynamics of piñon–juniper communities that predate intensive Euro-American settlement activities are poorly known or understood, while the intrinsic ecological, aesthetic, and economic values of old-growth woodlands are often overlooked. Historical changes in piñon–juniper stands include two related, but poorly differentiated processes: recent tree expansion into grass- or shrub-dominated (i.e., non-woodland) vegetation and thickening or infilling of savanna or mosaic woodlands predating settlement. Our work addresses the expansion pattern, modeling the occurrence of “older” savanna and woodland stands extant prior to 1850 in contrast to “younger” piñon–juniper growth of more recent, postsettlement origin. We present criteria in the form of a diagnostic key for distinguishing “older,” pre-Euro-American settlement piñon–juniper from “younger” (post-1850) stands and report results of predictive modeling and mapping efforts within a north-central New Mexico study area. Selected models suggest a primary role for soil moisture in the current distribution of “old” vs. “young” piñon–juniper stands. Presettlement era woodlands are shown to occupy a discrete ecological space, defined by the interaction of effective (seasonal) moisture with landform setting and fine-scale (soil/water) depositional patterns. “Older” stands are generally found at higher elevations or on skeletal soils in upland settings, while “younger” stands (often dominated by one-seed juniper, Juniperus monosperma) are most common at lower

  5. Novel Approach for Evaluating Secondary Organic Aerosol from Aromatic Hydrocarbons: Unified Method for Predicting Aerosol Composition and Formation.

    PubMed

    Li, Lijie; Tang, Ping; Nakao, Shunsuke; Kacarab, Mary; Cocker, David R

    2016-06-21

    Innovative secondary organic aerosol (SOA) composition analysis methods normalizing aerosol yield and chemical composition on an aromatic ring basis are developed and utilized to explore aerosol formation from oxidation of aromatic hydrocarbons. SOA yield and chemical composition are revisited using 15 years of University of California, Riverside/CE-CERT environmental chamber data on 17 aromatic hydrocarbons with HC:NO ranging from 11.1 to 171 ppbC:ppb. SOA yield is redefined in this work by normalizing the molecular weight of all aromatic precursors to the molecular weight of the aromatic ring [Formula: see text], where i is the aromatic hydrocarbon precursor. The yield normalization process demonstrates that the amount of aromatic rings present is a more significant driver of aerosol formation than the vapor pressure of the precursor aromatic. Yield normalization also provided a basis to evaluate isomer impacts on SOA formation. Further, SOA elemental composition is explored relative to the aromatic ring rather than on a classical mole basis. Generally, four oxygens per aromatic ring are observed in SOA, regardless of the alkyl substitutes attached to the ring. Besides the observed SOA oxygen to ring ratio (O/R ∼ 4), a hydrogen to ring ratio (H/R) of 6 + 2n is observed, where n is the number of nonaromatic carbons. Normalization of yield and composition to the aromatic ring clearly demonstrates the greater significance of aromatic ring carbons compared with alkyl carbon substituents in determining SOA formation and composition. PMID:27177154

  6. Differential Effects of Two Types of Formative Assessment in Predicting Performance of First-Year Medical Students

    ERIC Educational Resources Information Center

    Krasne, Sally; Wimmers, Paul F.; Relan, Anju; Drake, Thomas A.

    2006-01-01

    Formative assessments are systematically designed instructional interventions to assess and provide feedback on students' strengths and weaknesses in the course of teaching and learning. Despite their known benefits to student attitudes and learning, medical school curricula have been slow to integrate such assessments into the curriculum. This…

  7. Use of SDWBA predictions for acoustic volume backscattering and the Self-Organizing Map to discern frequencies identifying Meganyctiphanes norvegica from mesopelagic fish species

    NASA Astrophysics Data System (ADS)

    Peña, M.; Calise, L.

    2016-04-01

    To acoustically assess the biomass of multiple species or taxa within a survey region, the volume backscatter data should be apportioned to the constituent sound scatterers. Typically, measured backscatter is attributed to certain species using predictions at different frequencies, mostly based on the difference in scattering at the frequencies of 38 and 120 kHz (dual frequency method). We used the full version of the stochastic distortedwave Born approximation (SDWBA) model to predict backscatter spectra for Meganyctiphanes norvegica and to explore the sensitivities of ΔMVBS to the model parameters, e.g. acoustic frequency and incidence angle, and animal density and sound speed contrast, length, and shape. The orientation is almost the unique parameter responsible for variation, with fatness affecting longer lengths. We present a summary of ΔMVBS that can serve as the basis for identification algorithms. Next, we simulate the scenario encountered in the Balearic Sea (western Mediterranean) where Northern krill are mixed with mesopelagic fish species (bristlemouths and lanternfishes), which are modeled with a prolate spheroid model. Simulated numerical data are employed to emulate the discrimination process with the most common identification techniques and typical survey frequencies. The importance of using density-independent techniques for acoustic classification is highlighted. Finally, an unsupervised neural network, the Self-Organizing Map (SOM), is used to cluster these theoretical data and identify the frequencies that provide, in this case, the most classification potential. The simulation results confirm that pairs of frequencies spanning the Rayleigh and geometric scattering regimes of the targets are the most useful for clustering; a minimum of four frequencies are necessary to separate the three species, while three frequencies are able to differentiate krill from mesopelagic fish species.

  8. Characterization of dissolved organic matter for prediction of trihalomethane formation potential in surface and sub-surface waters.

    PubMed

    Awad, John; van Leeuwen, John; Chow, Christopher; Drikas, Mary; Smernik, Ronald J; Chittleborough, David J; Bestland, Erick

    2016-05-01

    Dissolved organic matter (DOM) in surface waters used for drinking purposes can vary markedly in character dependent on their sources within catchments. The character of DOM further influences the formation of disinfection by products when precursor DOM present in drinking water reacts with chlorine during disinfection. Here we report the development of models that describe the formation potential of trihalomethanes (THMFP) dependent on the character of DOM in waters from discrete catchments with specific land-use and soil textures. DOM was characterized based on UV absorbance at 254 nm, apparent molecular weight and relative abundances of protein-like and humic-like compounds. DOM character and Br concentration (up to 0.5 mg/L) were used as variables in models (R(2)>0.93) of THMFP, which ranged from 19 to 649 μg/L. Chloroform concentration (12-594 μg/L) and relative abundance (27-99%) were first modeled (R(2)>0.85) and from these, the abundances of bromodichloromethane and chlorodibromomethane estimated using power and exponential functions, respectively (R(2)>0.98). From these, the abundance of bromoform is calculated. The proposed model may be used in risk assessment of catchment factors on formation of trihalomethanes in drinking water, in context of treatment efficiency for removal of organic matter. PMID:26874432

  9. Prediction of successive steps of SOM formation in aggregates and density fractions based on the 13C natural abundance

    NASA Astrophysics Data System (ADS)

    Gunina, Anna; Kuzyakov, Yakov

    2014-05-01

    Aggregate formation is a key process of soil development, which promotes carbon (C) stabilization by hindering decomposition of particulate organic matter (POM) and its interactions with mineral particles. C stabilization processes lead to 13C fractionation and consequently to various δ13C values of soil organic matter (SOM) fractions. Differences in δ13C within the aggregates and fractions may have two reasons: 1) preferential stabilization of organic compounds with light or heavy δ13C and/or 2) stabilization of organic materials after passing one or more microbial utilization cycles, leading to heavier δ13C in remaining C. We hypothesized that: 1) 13C enrichment between the SOM fractions corresponds to successive steps of SOM formation; 2) 13C fractionation (but not the δ13C signature) depends mainly on the transformation steps and not on the C precursors. Consequently, minimal differences between Δ13C of SOM fractions between various ecosystems correspond to maximal probability of the SOM formation pathways. We tested these hypotheses on three soils formed from cover loam during 45 years of growth of coniferous or deciduous forests or arable crops. Organic C pools in large macroaggregates, small macroaggregates, and microaggregates were fractionated sequentially for four density fractions to obtain free POM with ρ

  10. Map Scale in the Context of Progress in Soil Geography

    NASA Astrophysics Data System (ADS)

    Miller, Bradley; Schaetzl, Randall

    2014-05-01

    In this presentation, we review historical soil maps from a geographical perspective, in contrast to the more traditional temporal perspective. Our geographical perspective is operationalized by comparing soil maps based on their scale and classification system. To analyze the connection between scale in historical soil maps and their associated classification systems, we place soil maps into three categories of cartographic scale. We then examine how categories of cartographic scale correspond to the selection of environmental soil predictors used to initially create the maps, as reflected by the maps' legend. Previous analyses of soil mapping from the temporal perspective have concluded that soil classification systems have co-evolved with gains in soil knowledge. We conclude that paradigm shifts in soil mapping and classification can be better explained by their correlation to historical improvements in scientific understanding, differences in purpose for mapping, and advancement in geographic technologies. We observe that, throughout history, small cartographic scale maps have tended to emphasize climate-vegetation zonation. Medium cartographic scale maps have put more emphasis on parent material as a variable to explain soil distributions. And finally, soil maps at large cartographic scales have relied more on topography as a predictive factor. Importantly, a key characteristic of modern soil classification systems is their multi-scale approach, which incorporates these phenomena scales within their classification hierarchies. Although most modern soil classification systems are based on soil properties, the soil map remains a model, the purpose of which is to predict the spatial distributions of those properties. Hence, multi-scale classification systems still tend to be organized, at least in part, by this observed spatial hierarchy. Although the hierarchy observed in this study is generally known in pedology today, it also represents a new view on the

  11. Molecular tendrils feeding star formation in the Eye of the Medusa. The Medusa merger in high resolution 12CO 2-1 maps

    NASA Astrophysics Data System (ADS)

    König, S.; Aalto, S.; Lindroos, L.; Muller, S.; Gallagher, J. S.; Beswick, R. J.; Petitpas, G.; Jütte, E.

    2014-09-01

    Studying molecular gas properties in merging galaxies gives us important clues to the onset and evolution of interaction-triggered starbursts. NGC 4194 (the Medusa merger) is particularly interesting to study, since its FIR-to-CO luminosity ratio rivals that of ultraluminous galaxies (ULIRGs), despite its lower luminosity compared to ULIRGs, which indicates a high star formation efficiency (SFE) that is relative to even most spirals and ULIRGs. We study the molecular medium at an angular resolution of 0.65'' × 0.52'' (~120 × 98 pc) through our observations of 12CO 2-1 emission using the Submillimeter Array (SMA). We compare our 12CO 2-1 maps with the optical Hubble Space Telescope and high angular resolution radio continuum images to study the relationship between molecular gas and the other components of the starburst region. The molecular gas is tracing the complicated dust lane structure of NGC 4194 with the brightest emission being located in an off-nuclear ring-like structure with ~320 pc radius, the Eye of the Medusa. The bulk CO emission of the ring is found south of the kinematical center of NGC 4194. The northern tip of the ring is associated with the galaxy nucleus, where the radio continuum has its peak. Large velocity widths associated with the radio nucleus support the notion of NGC 4194 hosting an active galactic nucleus. A prominent, secondary emission maximum in the radio continuum is located inside the molecular ring. This suggests that the morphology of the ring is partially influenced by massive supernova explosions. From the combined evidence, we propose that the Eye of the Medusa contains a shell of swept up material where we identify a number of giant molecular associations. We propose that the Eye may be the site of an efficient starburst of 5-7 M⊙ yr-1, but it would still constitute only a fraction of the 30-50 M⊙ yr-1 star formation rate of the Medusa. Furthermore, we find that ~50% of the molecular mass of NGC 4194 is found in

  12. Mapping gas-phase organic reactivity and concomitant secondary organic aerosol formation: chemometric dimension reduction techniques for the deconvolution of complex atmospheric datasets

    NASA Astrophysics Data System (ADS)

    Wyche, K. P.; Monks, P. S.; Smallbone, K. L.; Hamilton, J. F.; Alfarra, M. R.; Rickard, A. R.; McFiggans, G. B.; Jenkin, M. E.; Bloss, W. J.; Ryan, A. C.; Hewitt, C. N.; MacKenzie, A. R.

    2015-01-01

    Highly non-linear dynamical systems, such as those found in atmospheric chemistry, necessitate hierarchical approaches to both experiment and modeling in order, ultimately, to identify and achieve fundamental process-understanding in the full open system. Atmospheric simulation chambers comprise an intermediate in complexity, between a classical laboratory experiment and the full, ambient system. As such, they can generate large volumes of difficult-to-interpret data. Here we describe and implement a chemometric dimension reduction methodology for the deconvolution and interpretation of complex gas- and particle-phase composition spectra. The methodology comprises principal component analysis (PCA), hierarchical cluster analysis (HCA) and positive least squares-discriminant analysis (PLS-DA). These methods are, for the first time, applied to simultaneous gas- and particle-phase composition data obtained from a comprehensive series of environmental simulation chamber experiments focused on biogenic volatile organic compound (BVOC) photooxidation and associated secondary organic aerosol (SOA) formation. We primarily investigated the biogenic SOA precursors isoprene, α-pinene, limonene, myrcene, linalool and β-caryophyllene. The chemometric analysis is used to classify the oxidation systems and resultant SOA according to the controlling chemistry and the products formed. Furthermore, a holistic view of results across both the gas- and particle-phases shows the different SOA formation chemistry, initiating in the gas-phase, proceeding to govern the differences between the various BVOC SOA compositions. The results obtained are used to describe the particle composition in the context of the oxidized gas-phase matrix. An extension of the technique, which incorporates into the statistical models data from anthropogenic (i.e. toluene) oxidation and "more realistic" plant mesocosm systems, demonstrates that such an ensemble of chemometric mapping has the potential to be

  13. Validation of flow simulation and gas combustion sub-models for the CFD-based prediction of NOx formation in biomass grate furnaces

    NASA Astrophysics Data System (ADS)

    Zahirović, Selma; Scharler, Robert; Kilpinen, Pia; Obernberger, Ingwald

    2010-12-01

    While reasonably accurate in simulating gas phase combustion in biomass grate furnaces, CFD tools based on simple turbulence-chemistry interaction models and global reaction mechanisms have been shown to lack in reliability regarding the prediction of NOx formation. Coupling detailed NOx reaction kinetics with advanced turbulence-chemistry interaction models is a promising alternative, yet computationally inefficient for engineering purposes. In the present work, a model is proposed to overcome these difficulties. The model is based on the Realizable k-ɛ model for turbulence, Eddy Dissipation Concept for turbulence-chemistry interaction and the HK97 reaction mechanism. The assessment of the sub-models in terms of accuracy and computational effort was carried out on three laboratory-scale turbulent jet flames in comparison with the experimental data. Without taking NOx formation into account, the accuracy of turbulence modelling and turbulence-chemistry interaction modelling was systematically examined on Sandia Flame D and Sandia CO/H2/N2 Flame B to support the choice of the associated models. As revealed by the Large Eddy Simulations of the former flame, the shortcomings of turbulence modelling by the Reynolds averaged Navier-Stokes (RANS) approach considerably influence the prediction of the mixing-dominated combustion process. This reduced the sensitivity of the RANS results to the variations of turbulence-chemistry interaction models and combustion kinetics. Issues related to the NOx formation with a focus on fuel bound nitrogen sources were investigated on a NH3-doped syngas flame. The experimentally observed trend in NOx yield from NH3 was correctly reproduced by HK97, whereas the replacement of its combustion subset by that of a detailed reaction scheme led to a more accurate agreement, but at increased computational costs. Moreover, based on results of simulations with HK97, the main features of the local course of the NOx formation processes were

  14. Mapping the homotypic binding sites in CD31 and the role of CD31 adhesion in the formation of interendothelial cell contacts

    PubMed Central

    1995-01-01

    CD31 is a member of the immunoglobulin superfamily consisting of six Ig- related domains. It is constitutively expressed by platelets, monocytes, and some lymphocytes, but at tenfold higher levels on vascular endothelial cells. CD31 has both homotypic and heterotypic adhesive properties. We have mapped the homotypic binding sites using a deletion series of CD31-Fc chimeras and a panel of anti-CD31 monoclonal antibodies. An extensive surface of CD31 is involved in homotypic binding with domains 2 and 3 and domains 5 and 6 playing key roles. A model consistent with the experimental data is that CD31 on one cell binds to CD31 on an apposing cell in an antiparallel interdigitating mode requiring full alignment of the six domains of each molecule. In addition to establishing intercellular homotypic contacts. CD31 binding leads to augmented adhesion via beta 1 integrins. The positive cooperation between CD31 and beta 1 integrins can occur in heterologous primate cells (COS cells). The interaction is specific to both CD31 and beta 1 integrins. Neither intercellular adhesion molecule-1 (ICAM- 1)/leukocyte function-associated antigen-1 (LCAM-1) nor neural cell adhesion molecule (NCAM)/NCAM adhesion leads to recruitment of beta 1 integrin adhesion pathways. Establishment of CD31 contacts have effects on the growth and morphology of endothelial cells. CD31(D1-D6)Fc inhibits the growth of endothelial cells in culture. In addition, papain fragments of anti-CD31 antibodies (Fab fragments) disrupt interendothelial contact formation and monolayer integrity when intercellular contacts are being formed. The same reagents are without effect once these contacts have been established, suggesting that CD31- CD31 interactions are critically important only in the initial phases of intercellular adhesion. PMID:7534767

  15. Prediction of acrylamide formation in biscuits based on fingerprint data generated by ambient ionization mass spectrometry employing direct analysis in real time (DART) ion source.

    PubMed

    Vaclavik, Lukas; Capuano, Edoardo; Gökmen, Vural; Hajslova, Jana

    2015-04-15

    The objective of this study is the evaluation of the potential of high-throughput direct analysis in real time-high resolution mass spectrometry (DART-HRMS) fingerprinting and multivariate regression analysis in prediction of the extent of acrylamide formation in biscuit samples prepared by various recipes and baking conditions. Information-rich mass spectral fingerprints were obtained by analysis of biscuit extracts for preparation of which aqueous methanol was used. The principal component analysis (PCA) of the acquired data revealed an apparent clustering of samples according to the extent of heat-treatment applied during the baking of the biscuits. The regression model for prediction of acrylamide in biscuits was obtained by partial least square regression (PLSR) analysis of the data matrix representing combined positive and negative ionization mode fingerprints. The model provided a least root mean square error of cross validation (RMSECV) equal to an acrylamide concentration of 5.4 μg kg(-1) and standard error of prediction (SEP) of 14.8 μg kg(-1). The results obtained indicate that this strategy can be used to accurately predict the amounts of acrylamide formed during baking of biscuits. Such rapid estimation of acrylamide concentration can become a useful tool in evaluation of the effectivity of processes aiming at mitigation of this food processing contaminant. However, the robustness this approach with respect to variability in the chemical composition of ingredients used for preparation of biscuits should be tested further.

  16. In vivo clearance of ethoxycoumarin and its prediction from In vitro systems. Use Of drug depletion and metabolite formation methods in hepatic microsomes and isolated hepatocytes.

    PubMed

    Carlile, D J; Stevens, A J; Ashforth, E I; Waghela, D; Houston, J B

    1998-03-01

    The pharmacokinetics of ethoxycoumarin have been characterized using steady-state plasma concentrations achieved after administration of this compound, at a series of infusion rates, into the hepatic portal vein of rats. The clearance of ethoxycoumarin could be described by a one-site Michaelis-Menten kinetic model with Vmax and unbound KM values of 495 nmol/min/standard rat weight (SRW) and 3.6 microM, respectively, and an intrinsic clearance (CLint, Vmax/KM ratio) of 137 ml/min/SRW (where SRW is 250 g). Urinary excretion experiments, using both ethoxycoumarin and hydroxycoumarin, demonstrated that 7-hydroxycoumarin, the metabolite frequently measured in in vitro studies, accounted for 26% of the metabolism of ethoxycoumarin. In vitro studies with hepatic microsomes and isolated hepatocytes were undertaken to characterize the kinetics of both hydroxycoumarin formation and ethoxycoumarin depletion and to compare the utility of these methods for predicting in vivo clearance. In both in vitro systems, hydroxycoumarin formation displayed biphasic kinetics, with a high-affinity/low-capacity component (with Vmax, KM, and CL1 terms) and a low-affinity/high-capacity component (with a CL2 term) that was not saturated over the substrate concentration range studied (0.5-100 microM). The use of scaling factors to relate in vitro and in vivo data showed that, although microsomal and hepatocyte Vmax values were comparable (26 and 17 nmol/min/SRW, respectively), both were substantially lower than the in vivo value. However, scaling of the in vitro CLint values, by taking into account the fraction of ethoxycoumarin metabolized to hydroxycoumarin, yielded in vivo predictions of 127 and 122 ml/min/SRW (representing 93 and 89% of the observed CLint value) for microsomes and hepatocytes, respectively. The depletion of ethoxycoumarin (1-1.5 microM) with time in both microsomes and hepatocytes displayed a monoexponential decline and predicted in vivo CLint values of 53 and 117 ml

  17. Control over the strength of connections between modules: a double dissociation between stimulus format and task revealed by Granger causality mapping in fMRI

    PubMed Central

    Anderson, Britt; Soliman, Sherif; O’Malley, Shannon; Danckert, James; Besner, Derek

    2015-01-01

    Drawing on theoretical and computational work with the localist dual route reading model and results from behavioral studies, Besner et al. (2011) proposed that the ability to perform tasks that require overriding stimulus-specific defaults (e.g., semantics when naming Arabic numerals, and phonology when evaluating the parity of number words) necessitate the ability to modulate the strength of connections between cognitive modules for lexical representation, semantics, and phonology on a task- and stimulus-specific basis. We used functional magnetic resonance imaging to evaluate this account by assessing changes in functional connectivity while participants performed tasks that did and did not require such stimulus-task default overrides. The occipital region showing the greatest modulation of BOLD signal strength for the two stimulus types was used as the seed region for Granger causality mapping (GCM). Our GCM analysis revealed a region of rostromedial frontal cortex with a crossover interaction. When participants performed tasks that required overriding stimulus type defaults (i.e., parity judgments of number words and naming Arabic numerals) functional connectivity between the occipital region and rostromedial frontal cortex was present. Statistically significant functional connectivity was absent when the tasks were the default for the stimulus type (i.e., parity judgments of Arabic numerals and reading number words). This frontal region (BA 10) has previously been shown to be involved in goal-directed behavior and maintenance of a specific task set. We conclude that overriding stimulus-task defaults requires a modulation of connection strengths between cognitive modules and that the override mechanism predicted from cognitive theory is instantiated by frontal modulation of neural activity of brain regions specialized for sensory processing. PMID:25870571

  18. Actin-interacting and flagellar proteins in Leishmania spp.: Bioinformatics predictions to functional assignments in phagosome formation

    PubMed Central

    2009-01-01

    Several motile processes are responsible for the movement of proteins into and within the flagellar membrane, but little is known about the process by which specific proteins (either actin-associated or not) are targeted to protozoan flagellar membranes. Actin is a major cytoskeleton protein, while polymerization and depolymerization of parasite actin and actin-interacting proteins (AIPs) during both processes of motility and host cell entry might be key events for successful infection. For a better understanding the eukaryotic flagellar dynamics, we have surveyed genomes, transcriptomes and proteomes of pathogenic Leishmania spp. to identify pertinent genes/proteins and to build in silico models to properly address their putative roles in trypanosomatid virulence. In a search for AIPs involved in flagellar activities, we applied computational biology and proteomic tools to infer from the biological meaning of coronins and Arp2/3, two important elements in phagosome formation after parasite phagocytosis by macrophages. Results presented here provide the first report of Leishmania coronin and Arp2/3 as flagellar proteins that also might be involved in phagosome formation through actin polymerization within the flagellar environment. This is an issue worthy of further in vitro examination that remains now as a direct, positive bioinformatics-derived inference to be presented. PMID:21637533

  19. Actin-interacting and flagellar proteins in Leishmania spp.: Bioinformatics predictions to functional assignments in phagosome formation.

    PubMed

    Diniz, Michely C; Costa, Marcília P; Pacheco, Ana C L; Kamimura, Michel T; Silva, Samara C; Carneiro, Laura D G; Sousa, Ana P L; Soares, Carlos E A; Souza, Celeste S F; de Oliveira, Diana Magalhães

    2009-07-01

    Several motile processes are responsible for the movement of proteins into and within the flagellar membrane, but little is known about the process by which specific proteins (either actin-associated or not) are targeted to protozoan flagellar membranes. Actin is a major cytoskeleton protein, while polymerization and depolymerization of parasite actin and actin-interacting proteins (AIPs) during both processes of motility and host cell entry might be key events for successful infection. For a better understanding the eukaryotic flagellar dynamics, we have surveyed genomes, transcriptomes and proteomes of pathogenic Leishmania spp. to identify pertinent genes/proteins and to build in silico models to properly address their putative roles in trypanosomatid virulence. In a search for AIPs involved in flagellar activities, we applied computational biology and proteomic tools to infer from the biological meaning of coronins and Arp2/3, two important elements in phagosome formation after parasite phagocytosis by macrophages. Results presented here provide the first report of Leishmania coronin and Arp2/3 as flagellar proteins that also might be involved in phagosome formation through actin polymerization within the flagellar environment. This is an issue worthy of further in vitro examination that remains now as a direct, positive bioinformatics-derived inference to be presented. PMID:21637533

  20. Prediction of hydrodynamics and chemistry of confined turbulent methane-air flames with attention to formation of oxides of nitrogen

    NASA Technical Reports Server (NTRS)

    Elghobashi, S.; Spalding, D. B.; Srivatsa, S. K.

    1977-01-01

    A formulation of the governing partial differential equations for fluid flow and reacting chemical species in a tubular combustor is presented. A numerical procedure for the solution of the governing differential equations is described, and models for chemical equilibrium and chemical kinetics calculations are presented. The chemical equilibrium model is used to characterize the hydrocarbon reactions. The chemical kinetics model is used to predict the concentrations of the oxides of nitrogen. The combustor consists of a cylindrical duct of varying cross sections with concentric streams of gaseous fuel and air entering the duct at one end. Four sample cases with specified inlet and boundary conditions are considered, and the results are discussed

  1. Modeling the formation of secondary organic aerosol (SOA). 2. The predicted effects of relative humidity on aerosol formation in the alpha-pinene-, beta-pinene-, sabinene-, delta 3-carene-, and cyclohexene-ozone systems.

    PubMed

    Seinfeld, J H; Erdakos, G B; Asher, W E; Pankow, J F

    2001-05-01

    Atmospheric oxidation of volatile organic compounds can lead to the formation of secondary organic aerosol (SOA) through the gas/particle (G/P) partitioning of the oxidation products. Since water is ubiquitous in the atmosphere, the extent of the partitioning for any individual organic product depends not only on the amounts and properties of the partitioning organic compounds, but also on the amount of water present. Predicting the effects of water on the atmospheric G/P distributions of organic compounds is, therefore, central to understanding SOA formation. The goals of the current work are to gain understanding of how increases in RH affect (1) overall SOA yields, (2) water uptake by SOA, (3) the behaviors of individual oxidation products, and (4) the fundamental physical properties of the SOA phase that govern the G/P distribution of each of the oxidation products. Part 1 of this series considered SOA formation from five parent hydrocarbons in the absence of water. This paper predicts how adding RH to those systems uniformly increases both the amount of condensed organic mass and the amount of liquid water in the SOA phase. The presence of inorganic components is not considered. The effect of increasing RH is predicted to be stronger for SOA produced from cyclohexene as compared to SOA produced from four monoterpenes. This is likely a result of the greater general degree of oxidation (and hydrophilicity) of the cyclohexene products. Good agreement was obtained between predicted SOA yields and laboratory SOA yield data actually obtained in the presence of water. As RH increases, the compounds that play the largest roles in changing both the organic and water masses in the SOA phase are those with vapor pressures that are intermediate between those of essentially nonvolatile and highly volatile species. RH-driven changes in the compound-dependent G/P partitioning coefficient Kp result from changes in both the average molecular weight MWom of the absorbing

  2. An integrated QSAR-PBK/D modelling approach for predicting detoxification and DNA adduct formation of 18 acyclic food-borne α,β-unsaturated aldehydes

    SciTech Connect

    Kiwamoto, R. Spenkelink, A.; Rietjens, I.M.C.M.; Punt, A.

    2015-01-01

    Acyclic α,β-unsaturated aldehydes present in food raise a concern because the α,β-unsaturated aldehyde moiety is considered a structural alert for genotoxicity. However, controversy remains on whether in vivo at realistic dietary exposure DNA adduct formation is significant. The aim of the present study was to develop physiologically based kinetic/dynamic (PBK/D) models to examine dose-dependent detoxification and DNA adduct formation of a group of 18 food-borne acyclic α,β-unsaturated aldehydes without 2- or 3-alkylation, and with no more than one conjugated double bond. Parameters for the PBK/D models were obtained using quantitative structure–activity relationships (QSARs) defined with a training set of six selected aldehydes. Using the QSARs, PBK/D models for the other 12 aldehydes were defined. Results revealed that DNA adduct formation in the liver increases with decreasing bulkiness of the molecule especially due to less efficient detoxification. 2-Propenal (acrolein) was identified to induce the highest DNA adduct levels. At realistic dietary intake, the predicted DNA adduct levels for all aldehydes were two orders of magnitude lower than endogenous background levels observed in disease free human liver, suggesting that for all 18 aldehydes DNA adduct formation is negligible at the relevant levels of dietary intake. The present study provides a proof of principle for the use of QSAR-based PBK/D modelling to facilitate group evaluations and read-across in risk assessment. - Highlights: • Physiologically based in silico models were made for 18 α,β-unsaturated aldehydes. • Kinetic parameters were determined by in vitro incubations and a QSAR approach. • DNA adduct formation was negligible at levels relevant for dietary intake. • The use of QSAR-based PBK/D modelling facilitates group evaluations and read-across.

  3. Development of base maps' role in soil mapping

    NASA Astrophysics Data System (ADS)

    Miller, Brad; Brevik, Eric

    2014-05-01

    One of the ultimate goals of soil science is the production of accurate soil maps, but historically these thematic maps have relied upon base maps for positional reference and later for parameters that help predict soil properties. This presentation reviews the history of base maps and the dependence of soil mapping on them. The availability of geographic technology for producing these base maps has constrained and directed the geographic study of soil. A lack of accurate methods for determining location limited early geographic description of soils to narratives. The availability of accurate topographic maps in the late 18th century, fueled by governments' interests in documenting national boundaries and popular interest in world atlases, provided the first base maps for soil geographers. These soil maps primarily used the topographic maps as a spatial reference onto which the thematic details were drawn. Due to the late start of a systematic topographic survey in the United States, early Soil Survey maps depended upon plat maps for spatial reference. The adoption of aerial photographs in the process of soil mapping increased the role of base maps as predictive parameters. In the current geospatial revolution, global positioning systems and geographic information systems have nearly replaced the need for base maps to provide spatial reference. Today, base maps are more likely to be used as parameters in landscape models for predicting the spatial distribution of soil properties and classes. As model parameters for digital soil maps, base maps constitute the library of predictive variables and constrain the supported resolution of the soil map. This change in the relationship between base maps and the soil map is a paradigm shift that affects fundamental definitions of geography, such as scale, resolution, and detectable features. These concepts are the essential tools used to study the spatial characteristics of Earth Systems.

  4. Geology of the Tulare Formation and other continental deposits, Kettleman City area, San Joaquin Valley, California, with a section on ground-water management considerations and use of texture maps

    USGS Publications Warehouse

    Page, R.W.

    1983-01-01

    The Tulare Formation and other continental deposits of Pliocene to Holocene age crop out over most of the area near Kettleman City in the San Joaquin Valley of California. The deposits range in thickness from 0 to more than 4,000 feet and overlie the upper Mya zone of the San Joaquin Formation of Pliocene age. Some features of their base reflect structural deformation during Quaternary time. Many freshwater fossils occur in the Tulare Formation itself, including the largest fossil assemblage of clams and snails known on the Pacific Coast. Sediments in the Tulare Formation and other continental deposits consist mainly of unconsolidated deposits of clay, silt, sand, and gravel. Texture maps of the Tulare Formation and other continental deposits show the distribution, both laterally and vertically, of the coarse- and fine-grained sediment in the area. Such maps can be used by water managers for selecting areas for recharge and discharge operations and by ground-water modelers for assigning relative values of hydraulic conductivity and storage coefficient. (USGS)

  5. Simulation of the Manufacturing of Non-Crimp Fabric-Reinforced Composite Wind Turbine Blades to Predict the Formation of Wave Defects

    NASA Astrophysics Data System (ADS)

    Fetfatsidis, K. A.; Sherwood, J. A.

    2011-05-01

    NCFs (Non-Crimp Fabrics) are commonly used in the design of wind turbine blades and other complex systems due to their ability to conform to complex shapes without the wrinkling that is typically experienced with woven fabrics or prepreg tapes. In the current research, a form of vacuum assisted resin transfer molding known as SCRIMP® is used to manufacture wind turbine blades. Often, during the compacting of the fabric layers by the vacuum pressure, several plies may bunch together out-of-plane and form wave defects. When the resin is infused, the areas beneath the waves become resin rich and can compromise the structural integrity of the blade. A reliable simulation tool is valuable to help predict where waves and other defects may appear as a result of the manufacturing process. Forming simulations often focus on the in-plane shearing and tensile behavior of fabrics and do not necessarily consider the bending stiffness of the fabrics, which is important to predict the formation of wrinkles and/or waves. This study incorporates experimentally determined in-plane shearing, tensile, and bending stiffness information of NCFs into a finite element model (ABAQUS/Explicit) of a 9-meter wind turbine blade to investigate the mechanical behaviors that can lead to the formation of waves as a result of the manufacturing process.

  6. Simulation of the Manufacturing of Non-Crimp Fabric-Reinforced Composite Wind Turbine Blades to Predict the Formation of Wave Defects

    SciTech Connect

    Fetfatsidis, K. A.; Sherwood, J. A.

    2011-05-04

    NCFs (Non-Crimp Fabrics) are commonly used in the design of wind turbine blades and other complex systems due to their ability to conform to complex shapes without the wrinkling that is typically experienced with woven fabrics or prepreg tapes. In the current research, a form of vacuum assisted resin transfer molding known as SCRIMP registered is used to manufacture wind turbine blades. Often, during the compacting of the fabric layers by the vacuum pressure, several plies may bunch together out-of-plane and form wave defects. When the resin is infused, the areas beneath the waves become resin rich and can compromise the structural integrity of the blade. A reliable simulation tool is valuable to help predict where waves and other defects may appear as a result of the manufacturing process. Forming simulations often focus on the in-plane shearing and tensile behavior of fabrics and do not necessarily consider the bending stiffness of the fabrics, which is important to predict the formation of wrinkles and/or waves. This study incorporates experimentally determined in-plane shearing, tensile, and bending stiffness information of NCFs into a finite element model (ABAQUS/Explicit) of a 9-meter wind turbine blade to investigate the mechanical behaviors that can lead to the formation of waves as a result of the manufacturing process.

  7. Obesity Prevalence Maps

    MedlinePlus

    ... Physical Activity Overweight & Obesity Healthy Weight Breastfeeding Micronutrient Malnutrition State and Local Programs Adult Obesity Prevalence Maps ... Physical Activity Overweight & Obesity Healthy Weight Breastfeeding Micronutrient Malnutrition State and Local Programs File Formats Help: How ...

  8. A stochastic model for retinocollicular map development

    PubMed Central

    Koulakov, Alexei A; Tsigankov, Dmitry N

    2004-01-01

    Background We examine results of gain-of-function experiments on retinocollicular maps in knock-in mice [Brown et al. (2000) Cell 102:77]. In wild-type mice the temporal-nasal axis of retina is mapped to the rostral-caudal axis of superior colliculus. The established map is single-valued, which implies that each point in retina maps to a unique termination zone in superior colliculus. In homozygous Isl2/EphA3 knock-in mice the map is double-valued, which means that each point on retina maps to two termination zones in superior colliculus. This is because about 50 percent of cells in retina express Isl2, and two types of projections, wild-type and Isl2/EphA3 positive, form two branches of the map. In heterozygous Isl2/EphA3 knock-ins the map is intermediate between the homozygous and wild-type: it is single-valued in temporal and double-valued in the nasal parts of retina. In this study we address possible reasons for such a bifurcation of the map. Results We study the map formation using stochastic model based on Markov chains. In our model the map undergoes a series of reconstructions with probabilities dependent upon a set of chemical cues. Our model suggests that the map in heterozygotes is single-valued in temporal region of retina for two reasons. First, the inhomogeneous gradient of endogenous receptor in retina makes the impact of exogenous receptor less significant in temporal retina. Second, the gradient of ephrin in the corresponding region of superior colliculus is smaller, which reduces the chemical signal-to-noise ratio. We predict that if gradient of ephrin is reduced by a genetic manipulation, the single-valued region of the map should extend to a larger portion of temporal retina, i.e. the point of transition between single-and doulble-valued maps should move to a more nasal position in Isl2-EphA3 heterozygotes. Conclusions We present a theoretical model for retinocollicular map development, which can account for intriguing behaviors observed in

  9. Prediction and characterization of heat-affected zone formation due to neighboring nickel-aluminum multilayer foil reaction

    SciTech Connect

    Adams, David P.; Hirschfeld, Deidre A.; Hooper, Ryan J.; Manuel, Michelle V.

    2015-09-01

    Reactive multilayer foils have the potential to be used as local high intensity heat sources for a variety of applications. Much of the past research effort concerning these materials have focused on understanding the structure-property relationships of the foils that govern the energy released during a reaction. To enhance the ability of researchers to more rapidly develop technologies based on reactive multilayer foils, a deeper and more predictive understanding of the relationship between the heat released from the foil and microstructural evolution in the neighboring materials is needed. This work describes the development of a numerical model for the purpose of evaluating new foil-substrate combinations for screening and optimization. The model is experimentally validated using a commercially available Ni-Al multilayer foils and different alloys.

  10. Ab initio chemical kinetics for H + NCN: prediction of NCN heat of formation and reaction product branching via doublet and quartet surfaces.

    PubMed

    Teng, Wen-Shuang; Moskaleva, Lyudmila V; Chen, Hui-Lung; Lin, M C

    2013-07-18

    The reaction of NCN with H atoms has been investigated by ab initio MO and RRKM theory calculations. The mechanisms for formation of major products on the doublet and quartet potential energy surfaces have been predicted at the CCSD(T) level of theory with the complete basis set limit. In addition, the heat of formation for NCN predicted at this rigorous level and those from five isogyric reactions are in close agreement with the best value based on the isodesmic process, (3)CCO + N2 = (3)NCN + CO, 109.4 kcal/mol, which lies within the two existing experimental values. The rate constants for the three possible reaction channels, H + NCN → CH + N2 (k(P1)), HCN + (4)N (k(QP1)), and HNC + (4)N (k(QP2)), have been calculated in the temperature range 298-3000 K. The results show that k(P1) is significantly higher than k(QP1) and k(QP2) and that the total rate constant agrees well with available experimental values in the whole temperature range studied. The kinetics of the reverse CH + N2 reaction has also been revisited at the CCSD(T)/CBS level; the predicted total rate constants at 760 Torr Ar pressure can be represented by kr = 4.01 × 10(-15) T(0.90) exp(-17.42 kcal mol(-1)/RT) cm(3) molecule(-1) s(-1) at T = 800-4000 K. The result agrees closely with the most recent experimental data and the best theoretical result of Harding et al. (J. Phys. Chem. A 2008, 112, 522) as well as that of Moskaleva and Lin (Proc. Combust. Inst. 2000, 28, 2393) evaluated with a steady-state approximation after a coding error correction made in this study. PMID:23755876

  11. Validity of the Military Applicant Profile (MAP) for Predicting Early Attrition in Different Educational, Age, and Racial Groups. Technical Report 567.

    ERIC Educational Resources Information Center

    Eaton, Newell K.; And Others

    The Military Applicant Profile (MAP) was developed to serve as an applicant screening instrument to reduce attrition in the all-volunteer Army. Since 1979, it has been used operationally to screen 17-year-old non-high school graduate males. The Army Research Institute was asked to explore the extension of MAP to older (above 17) nongraduate males,…

  12. A computer aided thermodynamic approach for predicting the formation of Z-DNA in naturally occurring sequences

    NASA Technical Reports Server (NTRS)

    Ho, P. S.; Ellison, M. J.; Quigley, G. J.; Rich, A.

    1986-01-01

    The ease with which a particular DNA segment adopts the left-handed Z-conformation depends largely on the sequence and on the degree of negative supercoiling to which it is subjected. We describe a computer program (Z-hunt) that is designed to search long sequences of naturally occurring DNA and retrieve those nucleotide combinations of up to 24 bp in length which show a strong propensity for Z-DNA formation. Incorporated into Z-hunt is a statistical mechanical model based on empirically determined energetic parameters for the B to Z transition accumulated to date. The Z-forming potential of a sequence is assessed by ranking its behavior as a function of negative superhelicity relative to the behavior of similar sized randomly generated nucleotide sequences assembled from over 80,000 combinations. The program makes it possible to compare directly the Z-forming potential of sequences with different base compositions and different sequence lengths. Using Z-hunt, we have analyzed the DNA sequences of the bacteriophage phi X174, plasmid pBR322, the animal virus SV40 and the replicative form of the eukaryotic adenovirus-2. The results are compared with those previously obtained by others from experiments designed to locate Z-DNA forming regions in these sequences using probes which show specificity for the left-handed DNA conformation.

  13. Structure prediction of magnetosome-associated proteins.

    PubMed

    Nudelman, Hila; Zarivach, Raz

    2014-01-01

    Magnetotactic bacteria (MTB) are Gram-negative bacteria that can navigate along geomagnetic fields. This ability is a result of a unique intracellular organelle, the magnetosome. These organelles are composed of membrane-enclosed magnetite (Fe3O4) or greigite (Fe3S4) crystals ordered into chains along the cell. Magnetosome formation, assembly, and magnetic nano-crystal biomineralization are controlled by magnetosome-associated proteins (MAPs). Most MAP-encoding genes are located in a conserved genomic region - the magnetosome island (MAI). The MAI appears to be conserved in all MTB that were analyzed so far, although the MAI size and organization differs between species. It was shown that MAI deletion leads to a non-magnetic phenotype, further highlighting its important role in magnetosome formation. Today, about 28 proteins are known to be involved in magnetosome formation, but the structures and functions of most MAPs are unknown. To reveal the structure-function relationship of MAPs we used bioinformatics tools in order to build homology models as a way to understand their possible role in magnetosome formation. Here we present a predicted 3D structural models' overview for all known Magnetospirillum gryphiswaldense strain MSR-1 MAPs.

  14. Mapping structural landmarks, ligand binding sites and missense mutations to the collagen IV heterotrimers predicts major functional domains, novel interactions and variation in phenotypes in inherited diseases affecting basement membranes

    PubMed Central

    Des Parkin, J.; San Antonio, James D.; Pedchenko, Vadim; Hudson, Billy; Jensen, Shane T.; Savige, Judy

    2016-01-01

    Collagen IV is the major protein found in basement membranes. It comprises 3 heterotrimers (α1α1α2, α3α4α5, and α5α5α6) that form distinct networks, and are responsible for membrane strength and integrity. We constructed linear maps of the collagen IV heterotrimers (‘interactomes’) that indicated major structural landmarks, known and predicted ligand-binding sites, and missense mutations, in order to identify functional and disease-associated domains, potential interactions between ligands, and genotype-phenotype relationships. The maps documented more than 30 known ligand-binding sites as well as motifs for integrins, heparin, von Willebrand factor (VWF), decorin and bone morphogenetic protein (BMP). They predicted functional domains for angiogenesis and haemostasis, and disease domains for autoimmunity, tumor growth and inhibition, infection and glycation. Cooperative ligand interactions were indicated by binding site proximity, for example, between integrins, matrix metalloproteinases and heparin. The maps indicated that mutations affecting major ligand-binding sites, for example for Von Hippel Lindau (VHL) protein in the α1 chain or integrins in the α5 chain, resulted in distinctive phenotypes (Hereditary Angiopathy, Nephropathy, Aneurysms and muscle Cramps (HANAC) syndrome, and early onset Alport syndrome respectively). These maps further our understanding of basement membrane biology and disease, and suggest novel membrane interactions, functions, and therapeutic targets. PMID:21280145

  15. Structure contour map of the tops of the Kreyenhagen Formation and Cretaceous strata in the Coalinga area, Fresno and Kings counties, California

    USGS Publications Warehouse

    Zigler, J.L.; Wentworth, C.M.; Bartow, J.A.

    1986-01-01

    This structure contour map, originally compiled during a study of the 1983 Coalinga earthquakes, shows the general structural configuration of the upper several kilometers of section in the Coalinga area. It was compiled by using electric well-log data available through April 1982 (Ammann Map Services, 1978; Petroleum Information Corporation, 1982; California Division of Oil and Gas, 1982) and surface geology (Dibblee, 1971; Mansfield, 1971).

  16. Modeling of Crude Oil Evaporation: A Bottom-Up Approach to Prediction of Potential Secondary Organic Aerosol Formation Following Oil Spills

    NASA Astrophysics Data System (ADS)

    Drozd, G.; Worton, D. R.; Variano, E. A.; Goldstein, A. H.

    2014-12-01

    Releases of hydrocarbons from oil spills can have large environmental impacts in both the ocean and atmosphere. While evaporation of oil following a spill is mainly modeled simply as a mass loss mechanism, the resulting production of atmospheric pollutants can also be a major concern, particularly for continental releases, such as wrecks of train-tanker or river barges, and near-shore rig releases. Both may occur near population centers. The Deepwater Horizon (DWH) spill in the Gulf of Mexico in 2010 presented a unique opportunity to observe significant secondary organic aerosol (SOA) production due to a large oil spill. Following on these observations, we have conducted a series of measurements on evaporation of oil while explicitly accounting for changes in chemical composition occurring as a function of evaporation time. In this work we use GC×GC-VUV-HRTOFMS to achieve unprecedented characterization of oil composition from the Deepwater Horizon (DWH) oil spill, and how it changes with time following release. Roughly 75% of the total mass of the alkane mixture comprising the oil was classified according to degree of branching, number of cyclic rings, aromatic character, and molecular weight. Such detailed and comprehensive characterization of the DWH oil allows for bottom-up estimates of the relationship between oil volatility and composition. We developed an evaporative model, based solely on our composition measurements and thermodynamic data (vapor pressure, enthalpy of vaporization), rather than common boiling point parameterizations, which is in excellent agreement with published mass evaporation rates and allows for prediction of potential SOA production as a function of both wind speed (evaporation rate) and oil composition. Our measurements yield different oil volatility distributions than previously inferred; this suggests accurate prediction of SOA formation requires detailed oil composition measurements. A wind tunnel was used to verify model

  17. Amyloid-PET predicts inhibition of de novo plaque formation upon chronic γ-secretase modulator treatment

    PubMed Central

    Brendel, M; Jaworska, A; Herms, J; Trambauer, J; Rötzer, C; Gildehaus, F-J; Carlsen, J; Cumming, P; Bylund, J; Luebbers, T; Bartenstein, P; Steiner, H; Haass, C; Baumann, K; Rominger, A

    2015-01-01

    In a positron-emission tomography (PET) study with the β-amyloid (Aβ) tracer [18F]-florbetaben, we previously showed that Aβ deposition in transgenic mice expressing Swedish mutant APP (APP-Swe) mice can be tracked in vivo. γ-Secretase modulators (GSMs) are promising therapeutic agents by reducing generation of the aggregation prone Aβ42 species without blocking general γ-secretase activity. We now aimed to investigate the effects of a novel GSM [8-(4-Fluoro-phenyl)-[1,2,4]triazolo[1,5–a]pyridin-2-yl]-[1-(3-methyl-[1,2,4]thiadiazol-5-yl)-piperidin-4-yl]-amine (RO5506284) displaying high potency in vitro and in vivo on amyloid plaque burden and used longitudinal Aβ-microPET to trace individual animals. Female transgenic (TG) APP-Swe mice aged 12 months (m) were assigned to vehicle (TG-VEH, n=12) and treatment groups (TG-GSM, n=12), which received daily RO5506284 (30 mg kg−1) treatment for 6 months. A total of 131 Aβ-PET recordings were acquired at baseline (12 months), follow-up 1 (16 months) and follow-up 2 (18 months, termination scan), whereupon histological and biochemical analyses of Aβ were performed. We analyzed the PET data as VOI-based cortical standard-uptake-value ratios (SUVR), using cerebellum as reference region. Individual plaque load assessed by PET remained nearly constant in the TG-GSM group during 6 months of RO5506284 treatment, whereas it increased progressively in the TG-VEH group. Baseline SUVR in TG-GSM mice correlated with Δ%-SUVR, indicating individual response prediction. Insoluble Aβ42 was reduced by 56% in the TG-GSM versus the TG-VEH group relative to the individual baseline plaque load estimates. Furthermore, plaque size histograms showed differing distribution between groups of TG mice, with fewer small plaques in TG-GSM animals. Taken together, in the first Aβ-PET study monitoring prolonged treatment with a potent GSM in an AD mouse model, we found clear attenuation of de novo amyloidogenesis. Moreover

  18. Isopach and structure contour maps of the Burro Canyon(?) Formation in the Chama-El Vado Area, Chama Basin, New Mexico

    USGS Publications Warehouse

    Ridgley, Jennie L.

    1983-01-01

    In the Chama Basin a wequence of conglomerate, sandstone, and red, gray-green, and pale-purple mudstone occurs stratigraphically between the Upper Jurassic Morrison Formation and Upper Cretaceous Dakota Sandstone. This stratigraphic interval has been called the Burro Canyon Formation by several workers (Craig and others, 1959; Smith and others, 1961; Saucier, 1974). Although similarities in lithology and stratigraphic position exist between this unit and the Burro Canyon Formation in Colorado, no direct correlation has been made between the two. For this reason the unit in the Chama Basin is called the Burro Canyon(?) Formation

  19. Isopach and structure contour maps of the Burro Canyon(?) Formation in the Mesa Golondrina and Mesa de los Viejos areas, Chama Basin, New Mexico

    USGS Publications Warehouse

    Ridgley, Jennie L.

    1983-01-01

    In the Chama Basin a wequence of conglomerate, sandstone, and red, gray-green, and pale-purple mudstone occurs stratigraphically between the Upper Jurassic Morrison Formation and Upper Cretaceous Dakota Sandstone. This stratigraphic interval has been called the Burro Canyon Formation by several workers (Craig and others, 1959; Smith and others, 1961; Saucier, 1974). Although similarities in lithology and stratigraphic position exist between this unit and the Burro Canyon Formation in Colorado, no direct correlation has been made between the two. For this reason the unit in the Chama Basin is called the Burro Canyon(?) Formation

  20. Theoretical study on the transition-metal oxoboryl complex: M-BO bonding nature, mechanism of the formation reaction, and prediction of a new oxoboryl complex.

    PubMed

    Zeng, Guixiang; Sakaki, Shigeyoshi

    2012-04-16

    The Pt-BO bonding nature and the formation reaction of the experimentally reported platinum(II) oxoboryl complex, simplified to PtBr(BO)(PMe(3))(2), were theoretically investigated with the density functional theory method. The BO(-) ligand was quantitatively demonstrated to have extremely strong σ-donation but very weak d(π)-electron-accepting abilities. Therefore, it exhibits a strong trans influence. The formation reaction occurs through a four-center transition state, in which the B(δ+)-Br(δ-) polarization and the Br → Si and O p(π) → B p(π) charge-transfer interactions play key roles. The Gibbs activation energy (ΔG°(++)) and Gibbs reaction energy (ΔG°) of the formation reaction are 32.2 and -6.1 kcal/mol, respectively. The electron-donating bulky phosphine ligand is found to be favorable for lowering both ΔG°(++) and ΔG°. In addition, the metal effect is examined with the nickel and palladium analogues and MBrCl[BBr(OSiMe(3))](CO)(PR(3))(2) (M = Ir and Rh). By a comparison of the ΔG°(++) and ΔG° values, the M-BO (M = Ni, Pd, Ir, and Rh) bonding nature, and the interaction energy between [MBrCl(CO)(PR(3))(2)](+) and BO(-) with those of the platinum system, MBrCl(BO)(CO)(PR(3))(2) (M = Ir and Rh) is predicted to be a good candidate for a stable oxoboryl complex. PMID:22458310

  1. Use of three-dimensional excitation and emission matrix fluorescence spectroscopy for predicting the disinfection by-product formation potential of reclaimed water.

    PubMed

    Hao, Ruixia; Ren, Huiqin; Li, Jianbing; Ma, Zhongzhi; Wan, Hongwen; Zheng, Xiaoying; Cheng, Shuiyuan

    2012-11-01

    This study was undertaken to demonstrate the feasibility of using three-dimensional excitation-emission matrix (3DEEM) fluorescence spectroscopy for the determination of chlorination disinfection by-product (DBP) precursors and the disinfection by-product formation potential (DBPFP) of reclaimed water samples. Two major DBP precursors were examined in this study, including humic acid (HA) and fulvic acid (FA). The 3DEEM fluorescence results obtained from various reclaimed water samples indicated that the reclaimed water samples were rich in fulvic acid-like substances that were associated with two main peaks (Ex/Em = 235-245/420-440 nm, and Ex/Em = 330-340/410-430 nm) in the fluorescence spectrum. The results also illustrated that the wavelength location of peak fluorescence intensity of a reclaimed water sample was independent of the influent water quality and the wastewater treatment process used in the reclamation plant. As a result, the peak fluorescence intensity and the wavelength location of the peak were used to identify the species of DBP precursors and their concentrations in the reclaimed water sample. Four regression models were then developed to relate the peak fluorescence intensity of the water sample to its DBPFP, including the formation potential of trihalomethane (THMFP) and the formation potential of haloacetic acid (HAAFP). The regression models were verified using the measured DBPFP results of a series of reclaimed water samples. It was found that the regression modeling results matched the measured DBPFP values well, with prediction errors below 10%. Therefore, the use of 3DEEM fluorescence spectroscopy together with the developed regression models in thi