Science.gov

Sample records for a-priori unknown environments

  1. A Priori Method of Using Photon Activation Analysis to Determine Unknown Trace Element Concentrations in NIST Standards

    SciTech Connect

    Green, Jaromy; Sun Zaijing; Wells, Doug

    2009-03-10

    Photon activation analysis detected elements in two NIST standards that did not have reported concentration values. A method is currently being developed to infer these concentrations by using scaling parameters and the appropriate known quantities within the NIST standard itself. Scaling parameters include: threshold, peak and endpoint energies; photo-nuclear cross sections for specific isotopes; Bremstrahlung spectrum; target thickness; and photon flux. Photo-nuclear cross sections and energies from the unknown elements must also be known. With these quantities, the same integral was performed for both the known and unknown elements resulting in an inference of the concentration of the un-reported elementmore » based on the reported value. Since Rb and Mn were elements that were reported in the standards, and because they had well-identified peaks, they were used as the standards of inference to determine concentrations of the unreported elements of As, I, Nb, Y, and Zr. This method was tested by choosing other known elements within the standards and inferring a value based on the stated procedure. The reported value of Mn in the first NIST standard was 403{+-}15 ppm and the reported value of Ca in the second NIST standard was 87000 ppm (no reported uncertainty). The inferred concentrations were 370{+-}23 ppm and 80200{+-}8700 ppm respectively.« less

  2. Autonomous exploration and mapping of unknown environments

    NASA Astrophysics Data System (ADS)

    Owens, Jason; Osteen, Phil; Fields, MaryAnne

    2012-06-01

    Autonomous exploration and mapping is a vital capability for future robotic systems expected to function in arbitrary complex environments. In this paper, we describe an end-to-end robotic solution for remotely mapping buildings. For a typical mapping system, an unmanned system is directed to enter an unknown building at a distance, sense the internal structure, and, barring additional tasks, while in situ, create a 2-D map of the building. This map provides a useful and intuitive representation of the environment for the remote operator. We have integrated a robust mapping and exploration system utilizing laser range scanners and RGB-D cameras, and we demonstrate an exploration and metacognition algorithm on a robotic platform. The algorithm allows the robot to safely navigate the building, explore the interior, report significant features to the operator, and generate a consistent map - all while maintaining localization.

  3. Towards high-speed autonomous navigation of unknown environments

    NASA Astrophysics Data System (ADS)

    Richter, Charles; Roy, Nicholas

    2015-05-01

    In this paper, we summarize recent research enabling high-speed navigation in unknown environments for dynamic robots that perceive the world through onboard sensors. Many existing solutions to this problem guarantee safety by making the conservative assumption that any unknown portion of the map may contain an obstacle, and therefore constrain planned motions to lie entirely within known free space. In this work, we observe that safety constraints may significantly limit performance and that faster navigation is possible if the planner reasons about collision with unobserved obstacles probabilistically. Our overall approach is to use machine learning to approximate the expected costs of collision using the current state of the map and the planned trajectory. Our contribution is to demonstrate fast but safe planning using a learned function to predict future collision probabilities.

  4. Autonomous Underwater Navigation and Optical Mapping in Unknown Natural Environments.

    PubMed

    Hernández, Juan David; Istenič, Klemen; Gracias, Nuno; Palomeras, Narcís; Campos, Ricard; Vidal, Eduard; García, Rafael; Carreras, Marc

    2016-07-26

    We present an approach for navigating in unknown environments while, simultaneously, gathering information for inspecting underwater structures using an autonomous underwater vehicle (AUV). To accomplish this, we first use our pipeline for mapping and planning collision-free paths online, which endows an AUV with the capability to autonomously acquire optical data in close proximity. With that information, we then propose a reconstruction pipeline to create a photo-realistic textured 3D model of the inspected area. These 3D models are also of particular interest to other fields of study in marine sciences, since they can serve as base maps for environmental monitoring, thus allowing change detection of biological communities and their environment over time. Finally, we evaluate our approach using the Sparus II, a torpedo-shaped AUV, conducting inspection missions in a challenging, real-world and natural scenario.

  5. Autonomous Underwater Navigation and Optical Mapping in Unknown Natural Environments

    PubMed Central

    Hernández, Juan David; Istenič, Klemen; Gracias, Nuno; Palomeras, Narcís; Campos, Ricard; Vidal, Eduard; García, Rafael; Carreras, Marc

    2016-01-01

    We present an approach for navigating in unknown environments while, simultaneously, gathering information for inspecting underwater structures using an autonomous underwater vehicle (AUV). To accomplish this, we first use our pipeline for mapping and planning collision-free paths online, which endows an AUV with the capability to autonomously acquire optical data in close proximity. With that information, we then propose a reconstruction pipeline to create a photo-realistic textured 3D model of the inspected area. These 3D models are also of particular interest to other fields of study in marine sciences, since they can serve as base maps for environmental monitoring, thus allowing change detection of biological communities and their environment over time. Finally, we evaluate our approach using the Sparus II, a torpedo-shaped AUV, conducting inspection missions in a challenging, real-world and natural scenario. PMID:27472337

  6. Exploration for Agents with Different Personalities in Unknown Environments

    NASA Astrophysics Data System (ADS)

    Doumit, Sarjoun; Minai, Ali

    We present in this paper a personality-based architecture (PA) that combines elements from the subsumption architecture and reinforcement learning to find alternate solutions for problems facing artificial agents exploring unknown environments. The underlying PA algorithm is decomposed into layers according to the different (non-contiguous) stages that our agent passes in, which in turn are influenced by the sources of rewards present in the environment. The cumulative rewards collected by an agent, in addition to its internal composition serve as factors in shaping its personality. In missions where multiple agents are deployed, our solution-goal is to allow each of the agents develop its own distinct personality in order for the collective to reach a balanced society, which then can accumulate the largest possible amount of rewards for the agent and society as well. The architecture is tested in a simulated matrix world which embodies different types of positive rewards and negative rewards. Varying experiments are performed to compare the performance of our algorithm with other algorithms under the same environment conditions. The use of our architecture accelerates the overall adaptation of the agents to their environment and goals by allowing the emergence of an optimal society of agents with different personalities. We believe that our approach achieves much efficient results when compared to other more restrictive policy designs.

  7. A priori stability results for PFC

    NASA Astrophysics Data System (ADS)

    Rossiter, J. A.

    2017-02-01

    Despite its popularity in industry and obvious efficacy, predictive functional control has few rigorous a priori stability results in the literature. In many cases, common sense and intuition with some trial and error are the main design tools. This paper seeks to tackle that gap by providing some analysis of the control law and showing what forms of stability assurances can be given and how these depend on the user choices of coincidence horizon and desired closed-loop pole. The conditions are separated into necessary, but not sufficient conditions for stability and, conversely, sufficient but not necessary conditions. Numerical examples demonstrate the efficacy of these conditions and the ease of use.

  8. A Priori Estimation of Organic Reaction Yields

    SciTech Connect

    Emami, Fateme S.; Vahid, Amir; Wylie, Elizabeth K.

    2015-07-21

    A thermodynamically guided calculation of free energies of substrate and product molecules allows for the estimation of the yields of organic reactions. The non-ideality of the system and the solvent effects are taken into account through the activity coefficients calculated at the molecular level by perturbed-chain statistical associating fluid theory (PC-SAFT). The model is iteratively trained using a diverse set of reactions with yields that have been reported previously. This trained model can then estimate a priori the yields of reactions not included in the training set with an accuracy of ca. ±15 %. This ability has the potential tomore » translate into significant economic savings through the selection and then execution of only those reactions that can proceed in good yields.« less

  9. Some Simultaneous Inference Procedures for A Priori Contrasts.

    ERIC Educational Resources Information Center

    Convey, John J.

    The testing of a priori contrasts, post hoc contrasts, and experimental error rates are discussed. Methods for controlling the experimental error rate for a set of a priori contrasts tested simultaneously have been developed by Dunnett, Dunn, Sidak, and Krishnaiah. Each of these methods is discussed and contrasted as to applicability, power, and…

  10. Realtime motion planning for a mobile robot in an unknown environment using a neurofuzzy based approach

    NASA Astrophysics Data System (ADS)

    Zheng, Taixiong

    2005-12-01

    A neuro-fuzzy network based approach for robot motion in an unknown environment was proposed. In order to control the robot motion in an unknown environment, the behavior of the robot was classified into moving to the goal and avoiding obstacles. Then, according to the dynamics of the robot and the behavior character of the robot in an unknown environment, fuzzy control rules were introduced to control the robot motion. At last, a 6-layer neuro-fuzzy network was designed to merge from what the robot sensed to robot motion control. After being trained, the network may be used for robot motion control. Simulation results show that the proposed approach is effective for robot motion control in unknown environment.

  11. Ratbot automatic navigation by electrical reward stimulation based on distance measurement in unknown environments.

    PubMed

    Gao, Liqiang; Sun, Chao; Zhang, Chen; Zheng, Nenggan; Chen, Weidong; Zheng, Xiaoxiang

    2013-01-01

    Traditional automatic navigation methods for bio-robots are constrained to configured environments and thus can't be applied to tasks in unknown environments. With no consideration of bio-robot's own innate living ability and treating bio-robots in the same way as mechanical robots, those methods neglect the intelligence behavior of animals. This paper proposes a novel ratbot automatic navigation method in unknown environments using only reward stimulation and distance measurement. By utilizing rat's habit of thigmotaxis and its reward-seeking behavior, this method is able to incorporate rat's intrinsic intelligence of obstacle avoidance and path searching into navigation. Experiment results show that this method works robustly and can successfully navigate the ratbot to a target in the unknown environment. This work might put a solid base for application of ratbots and also has significant implication of automatic navigation for other bio-robots as well.

  12. Pattern Recognition Algorithm for High-Sensitivity Odorant Detection in Unknown Environments

    NASA Technical Reports Server (NTRS)

    Duong, Tuan A.

    2012-01-01

    In a realistic odorant detection application environment, the collected sensory data is a mix of unknown chemicals with unknown concentrations and noise. The identification of the odorants among these mixtures is a challenge in data recognition. In addition, deriving their individual concentrations in the mix is also a challenge. A deterministic analytical model was developed to accurately identify odorants and calculate their concentrations in a mixture with noisy data.

  13. Optimal phase estimation with arbitrary a priori knowledge

    SciTech Connect

    Demkowicz-Dobrzanski, Rafal

    2011-06-15

    The optimal-phase estimation strategy is derived when partial a priori knowledge on the estimated phase is available. The solution is found with the help of the most famous result from the entanglement theory: the positive partial transpose criterion. The structure of the optimal measurements, estimators, and the optimal probe states is analyzed. This Rapid Communication provides a unified framework bridging the gap in the literature on the subject which until now dealt almost exclusively with two extreme cases: almost perfect knowledge (local approach based on Fisher information) and no a priori knowledge (global approach based on covariant measurements). Special attentionmore » is paid to a natural a priori probability distribution arising from a diffusion process.« less

  14. A Priori Knowledge and Heuristic Reasoning in Architectural Design.

    ERIC Educational Resources Information Center

    Rowe, Peter G.

    1982-01-01

    It is proposed that the various classes of a priori knowledge incorporated in heuristic reasoning processes exert a strong influence over architectural design activity. Some design problems require exercise of some provisional set of rules, inference, or plausible strategy which requires heuristic reasoning. A case study illustrates this concept.…

  15. A Real-Time Reaction Obstacle Avoidance Algorithm for Autonomous Underwater Vehicles in Unknown Environments

    PubMed Central

    Yan, Zheping; Li, Jiyun; Zhang, Gengshi; Wu, Yi

    2018-01-01

    A novel real-time reaction obstacle avoidance algorithm (RRA) is proposed for autonomous underwater vehicles (AUVs) that must adapt to unknown complex terrains, based on forward looking sonar (FLS). To accomplish this algorithm, obstacle avoidance rules are planned, and the RRA processes are split into five steps Introduction only lists 4 so AUVs can rapidly respond to various environment obstacles. The largest polar angle algorithm (LPAA) is designed to change detected obstacle’s irregular outline into a convex polygon, which simplifies the obstacle avoidance process. A solution is designed to solve the trapping problem existing in U-shape obstacle avoidance by an outline memory algorithm. Finally, simulations in three unknown obstacle scenes are carried out to demonstrate the performance of this algorithm, where the obtained obstacle avoidance trajectories are safety, smooth and near-optimal. PMID:29393915

  16. A Real-Time Reaction Obstacle Avoidance Algorithm for Autonomous Underwater Vehicles in Unknown Environments.

    PubMed

    Yan, Zheping; Li, Jiyun; Zhang, Gengshi; Wu, Yi

    2018-02-02

    A novel real-time reaction obstacle avoidance algorithm (RRA) is proposed for autonomous underwater vehicles (AUVs) that must adapt to unknown complex terrains, based on forward looking sonar (FLS). To accomplish this algorithm, obstacle avoidance rules are planned, and the RRA processes are split into five steps Introduction only lists 4 so AUVs can rapidly respond to various environment obstacles. The largest polar angle algorithm (LPAA) is designed to change detected obstacle's irregular outline into a convex polygon, which simplifies the obstacle avoidance process. A solution is designed to solve the trapping problem existing in U-shape obstacle avoidance by an outline memory algorithm. Finally, simulations in three unknown obstacle scenes are carried out to demonstrate the performance of this algorithm, where the obtained obstacle avoidance trajectories are safety, smooth and near-optimal.

  17. Automatic Artifact Removal from Electroencephalogram Data Based on A Priori Artifact Information.

    PubMed

    Zhang, Chi; Tong, Li; Zeng, Ying; Jiang, Jingfang; Bu, Haibing; Yan, Bin; Li, Jianxin

    2015-01-01

    Electroencephalogram (EEG) is susceptible to various nonneural physiological artifacts. Automatic artifact removal from EEG data remains a key challenge for extracting relevant information from brain activities. To adapt to variable subjects and EEG acquisition environments, this paper presents an automatic online artifact removal method based on a priori artifact information. The combination of discrete wavelet transform and independent component analysis (ICA), wavelet-ICA, was utilized to separate artifact components. The artifact components were then automatically identified using a priori artifact information, which was acquired in advance. Subsequently, signal reconstruction without artifact components was performed to obtain artifact-free signals. The results showed that, using this automatic online artifact removal method, there were statistical significant improvements of the classification accuracies in both two experiments, namely, motor imagery and emotion recognition.

  18. Automatic Artifact Removal from Electroencephalogram Data Based on A Priori Artifact Information

    PubMed Central

    Zhang, Chi; Tong, Li; Zeng, Ying; Jiang, Jingfang; Bu, Haibing; Li, Jianxin

    2015-01-01

    Electroencephalogram (EEG) is susceptible to various nonneural physiological artifacts. Automatic artifact removal from EEG data remains a key challenge for extracting relevant information from brain activities. To adapt to variable subjects and EEG acquisition environments, this paper presents an automatic online artifact removal method based on a priori artifact information. The combination of discrete wavelet transform and independent component analysis (ICA), wavelet-ICA, was utilized to separate artifact components. The artifact components were then automatically identified using a priori artifact information, which was acquired in advance. Subsequently, signal reconstruction without artifact components was performed to obtain artifact-free signals. The results showed that, using this automatic online artifact removal method, there were statistical significant improvements of the classification accuracies in both two experiments, namely, motor imagery and emotion recognition. PMID:26380294

  19. Solution of underdetermined systems of equations with gridded a priori constraints.

    PubMed

    Stiros, Stathis C; Saltogianni, Vasso

    2014-01-01

    The TOPINV, Topological Inversion algorithm (or TGS, Topological Grid Search) initially developed for the inversion of highly non-linear redundant systems of equations, can solve a wide range of underdetermined systems of non-linear equations. This approach is a generalization of a previous conclusion that this algorithm can be used for the solution of certain integer ambiguity problems in Geodesy. The overall approach is based on additional (a priori) information for the unknown variables. In the past, such information was used either to linearize equations around approximate solutions, or to expand systems of observation equations solved on the basis of generalized inverses. In the proposed algorithm, the a priori additional information is used in a third way, as topological constraints to the unknown n variables, leading to an R(n) grid containing an approximation of the real solution. The TOPINV algorithm does not focus on point-solutions, but exploits the structural and topological constraints in each system of underdetermined equations in order to identify an optimal closed space in the R(n) containing the real solution. The centre of gravity of the grid points defining this space corresponds to global, minimum-norm solutions. The rationale and validity of the overall approach are demonstrated on the basis of examples and case studies, including fault modelling, in comparison with SVD solutions and true (reference) values, in an accuracy-oriented approach.

  20. A priori discretization quality metrics for distributed hydrologic modeling applications

    NASA Astrophysics Data System (ADS)

    Liu, Hongli; Tolson, Bryan; Craig, James; Shafii, Mahyar; Basu, Nandita

    2016-04-01

    In distributed hydrologic modelling, a watershed is treated as a set of small homogeneous units that address the spatial heterogeneity of the watershed being simulated. The ability of models to reproduce observed spatial patterns firstly depends on the spatial discretization, which is the process of defining homogeneous units in the form of grid cells, subwatersheds, or hydrologic response units etc. It is common for hydrologic modelling studies to simply adopt a nominal or default discretization strategy without formally assessing alternative discretization levels. This approach lacks formal justifications and is thus problematic. More formalized discretization strategies are either a priori or a posteriori with respect to building and running a hydrologic simulation model. A posteriori approaches tend to be ad-hoc and compare model calibration and/or validation performance under various watershed discretizations. The construction and calibration of multiple versions of a distributed model can become a seriously limiting computational burden. Current a priori approaches are more formalized and compare overall heterogeneity statistics of dominant variables between candidate discretization schemes and input data or reference zones. While a priori approaches are efficient and do not require running a hydrologic model, they do not fully investigate the internal spatial pattern changes of variables of interest. Furthermore, the existing a priori approaches focus on landscape and soil data and do not assess impacts of discretization on stream channel definition even though its significance has been noted by numerous studies. The primary goals of this study are to (1) introduce new a priori discretization quality metrics considering the spatial pattern changes of model input data; (2) introduce a two-step discretization decision-making approach to compress extreme errors and meet user-specified discretization expectations through non-uniform discretization threshold

  1. Autonomous Unmanned Helicopter System for Remote Sensing Missions in Unknown Environments

    NASA Astrophysics Data System (ADS)

    Merz, T.; Chapman, S.

    2011-09-01

    This paper presents the design of an autonomous unmanned helicopter system for low-altitude remote sensing. The proposed concepts and methods are generic and not limited to a specific helicopter. The development was driven by the need for a dependable, modular, and affordable system with sufficient payload capacity suitable for both research and real-world deployment. The helicopter can be safely operated without a backup pilot in a contained area beyond visual range. This enables data collection in inaccessible or dangerous areas. Thanks to its terrain following and obstacle avoidance capability, the system does not require a priori information about terrain elevation and obstacles. Missions are specified in state diagrams and flight plans. We present performance characteristics of our system and show results of its deployment in real-world scenarios. We have successfully completed several dozen infrastructure inspection missions and crop monitoring missions facilitating plant phenomics studies.

  2. A hybrid search algorithm for swarm robots searching in an unknown environment.

    PubMed

    Li, Shoutao; Li, Lina; Lee, Gordon; Zhang, Hao

    2014-01-01

    This paper proposes a novel method to improve the efficiency of a swarm of robots searching in an unknown environment. The approach focuses on the process of feeding and individual coordination characteristics inspired by the foraging behavior in nature. A predatory strategy was used for searching; hence, this hybrid approach integrated a random search technique with a dynamic particle swarm optimization (DPSO) search algorithm. If a search robot could not find any target information, it used a random search algorithm for a global search. If the robot found any target information in a region, the DPSO search algorithm was used for a local search. This particle swarm optimization search algorithm is dynamic as all the parameters in the algorithm are refreshed synchronously through a communication mechanism until the robots find the target position, after which, the robots fall back to a random searching mode. Thus, in this searching strategy, the robots alternated between two searching algorithms until the whole area was covered. During the searching process, the robots used a local communication mechanism to share map information and DPSO parameters to reduce the communication burden and overcome hardware limitations. If the search area is very large, search efficiency may be greatly reduced if only one robot searches an entire region given the limited resources available and time constraints. In this research we divided the entire search area into several subregions, selected a target utility function to determine which subregion should be initially searched and thereby reduced the residence time of the target to improve search efficiency.

  3. Evolutionary Fuzzy Control and Navigation for Two Wheeled Robots Cooperatively Carrying an Object in Unknown Environments.

    PubMed

    Juang, Chia-Feng; Lai, Min-Ge; Zeng, Wan-Ting

    2015-09-01

    This paper presents a method that allows two wheeled, mobile robots to navigate unknown environments while cooperatively carrying an object. In the navigation method, a leader robot and a follower robot cooperatively perform either obstacle boundary following (OBF) or target seeking (TS) to reach a destination. The two robots are controlled by fuzzy controllers (FC) whose rules are learned through an adaptive fusion of continuous ant colony optimization and particle swarm optimization (AF-CACPSO), which avoids the time-consuming task of manually designing the controllers. The AF-CACPSO-based evolutionary fuzzy control approach is first applied to the control of a single robot to perform OBF. The learning approach is then applied to achieve cooperative OBF with two robots, where an auxiliary FC designed with the AF-CACPSO is used to control the follower robot. For cooperative TS, a rule for coordination of the two robots is developed. To navigate cooperatively, a cooperative behavior supervisor is introduced to select between cooperative OBF and cooperative TS. The performance of the AF-CACPSO is verified through comparisons with various population-based optimization algorithms for the OBF learning problem. Simulations and experiments verify the effectiveness of the approach for cooperative navigation of two robots.

  4. A priori discretization error metrics for distributed hydrologic modeling applications

    NASA Astrophysics Data System (ADS)

    Liu, Hongli; Tolson, Bryan A.; Craig, James R.; Shafii, Mahyar

    2016-12-01

    Watershed spatial discretization is an important step in developing a distributed hydrologic model. A key difficulty in the spatial discretization process is maintaining a balance between the aggregation-induced information loss and the increase in computational burden caused by the inclusion of additional computational units. Objective identification of an appropriate discretization scheme still remains a challenge, in part because of the lack of quantitative measures for assessing discretization quality, particularly prior to simulation. This study proposes a priori discretization error metrics to quantify the information loss of any candidate discretization scheme without having to run and calibrate a hydrologic model. These error metrics are applicable to multi-variable and multi-site discretization evaluation and provide directly interpretable information to the hydrologic modeler about discretization quality. The first metric, a subbasin error metric, quantifies the routing information loss from discretization, and the second, a hydrological response unit (HRU) error metric, improves upon existing a priori metrics by quantifying the information loss due to changes in land cover or soil type property aggregation. The metrics are straightforward to understand and easy to recode. Informed by the error metrics, a two-step discretization decision-making approach is proposed with the advantage of reducing extreme errors and meeting the user-specified discretization error targets. The metrics and decision-making approach are applied to the discretization of the Grand River watershed in Ontario, Canada. Results show that information loss increases as discretization gets coarser. Moreover, results help to explain the modeling difficulties associated with smaller upstream subbasins since the worst discretization errors and highest error variability appear in smaller upstream areas instead of larger downstream drainage areas. Hydrologic modeling experiments under

  5. Precise regional baseline estimation using a priori orbital information

    NASA Technical Reports Server (NTRS)

    Lindqwister, Ulf J.; Lichten, Stephen M.; Blewitt, Geoffrey

    1990-01-01

    A solution using GPS measurements acquired during the CASA Uno campaign has resulted in 3-4 mm horizontal daily baseline repeatability and 13 mm vertical repeatability for a 729 km baseline, located in North America. The agreement with VLBI is at the level of 10-20 mm for all components. The results were obtained with the GIPSY orbit determination and baseline estimation software and are based on five single-day data arcs spanning the 20, 21, 25, 26, and 27 of January, 1988. The estimation strategy included resolving the carrier phase integer ambiguities, utilizing an optial set of fixed reference stations, and constraining GPS orbit parameters by applying a priori information. A multiday GPS orbit and baseline solution has yielded similar 2-4 mm horizontal daily repeatabilities for the same baseline, consistent with the constrained single-day arc solutions. The application of weak constraints to the orbital state for single-day data arcs produces solutions which approach the precise orbits obtained with unconstrained multiday arc solutions.

  6. A Hybrid Search Algorithm for Swarm Robots Searching in an Unknown Environment

    PubMed Central

    Li, Shoutao; Li, Lina; Lee, Gordon; Zhang, Hao

    2014-01-01

    This paper proposes a novel method to improve the efficiency of a swarm of robots searching in an unknown environment. The approach focuses on the process of feeding and individual coordination characteristics inspired by the foraging behavior in nature. A predatory strategy was used for searching; hence, this hybrid approach integrated a random search technique with a dynamic particle swarm optimization (DPSO) search algorithm. If a search robot could not find any target information, it used a random search algorithm for a global search. If the robot found any target information in a region, the DPSO search algorithm was used for a local search. This particle swarm optimization search algorithm is dynamic as all the parameters in the algorithm are refreshed synchronously through a communication mechanism until the robots find the target position, after which, the robots fall back to a random searching mode. Thus, in this searching strategy, the robots alternated between two searching algorithms until the whole area was covered. During the searching process, the robots used a local communication mechanism to share map information and DPSO parameters to reduce the communication burden and overcome hardware limitations. If the search area is very large, search efficiency may be greatly reduced if only one robot searches an entire region given the limited resources available and time constraints. In this research we divided the entire search area into several subregions, selected a target utility function to determine which subregion should be initially searched and thereby reduced the residence time of the target to improve search efficiency. PMID:25386855

  7. Impact of modellers' decisions on hydrological a priori predictions

    NASA Astrophysics Data System (ADS)

    Holländer, H. M.; Bormann, H.; Blume, T.; Buytaert, W.; Chirico, G. B.; Exbrayat, J.-F.; Gustafsson, D.; Hölzel, H.; Krauße, T.; Kraft, P.; Stoll, S.; Blöschl, G.; Flühler, H.

    2014-06-01

    In practice, the catchment hydrologist is often confronted with the task of predicting discharge without having the needed records for calibration. Here, we report the discharge predictions of 10 modellers - using the model of their choice - for the man-made Chicken Creek catchment (6 ha, northeast Germany, Gerwin et al., 2009b) and we analyse how well they improved their prediction in three steps based on adding information prior to each following step. The modellers predicted the catchment's hydrological response in its initial phase without having access to the observed records. They used conceptually different physically based models and their modelling experience differed largely. Hence, they encountered two problems: (i) to simulate discharge for an ungauged catchment and (ii) using models that were developed for catchments, which are not in a state of landscape transformation. The prediction exercise was organized in three steps: (1) for the first prediction the modellers received a basic data set describing the catchment to a degree somewhat more complete than usually available for a priori predictions of ungauged catchments; they did not obtain information on stream flow, soil moisture, nor groundwater response and had therefore to guess the initial conditions; (2) before the second prediction they inspected the catchment on-site and discussed their first prediction attempt; (3) for their third prediction they were offered additional data by charging them pro forma with the costs for obtaining this additional information. Holländer et al. (2009) discussed the range of predictions obtained in step (1). Here, we detail the modeller's assumptions and decisions in accounting for the various processes. We document the prediction progress as well as the learning process resulting from the availability of added information. For the second and third steps, the progress in prediction quality is evaluated in relation to individual modelling experience and costs of

  8. Impact of modellers' decisions on hydrological a priori predictions

    NASA Astrophysics Data System (ADS)

    Holländer, H. M.; Bormann, H.; Blume, T.; Buytaert, W.; Chirico, G. B.; Exbrayat, J.-F.; Gustafsson, D.; Hölzel, H.; Krauße, T.; Kraft, P.; Stoll, S.; Blöschl, G.; Flühler, H.

    2013-07-01

    The purpose of this paper is to stimulate a re-thinking of how we, the catchment hydrologists, could become reliable forecasters. A group of catchment modellers predicted the hydrological response of a man-made 6 ha catchment in its initial phase (Chicken Creek) without having access to the observed records. They used conceptually different model families. Their modelling experience differed largely. The prediction exercise was organized in three steps: (1) for the 1st prediction modellers received a basic data set describing the internal structure of the catchment (somewhat more complete than usually available to a priori predictions in ungauged catchments). They did not obtain time series of stream flow, soil moisture or groundwater response. (2) Before the 2nd improved prediction they inspected the catchment on-site and attended a workshop where the modellers presented and discussed their first attempts. (3) For their improved 3rd prediction they were offered additional data by charging them pro forma with the costs for obtaining this additional information. Holländer et al. (2009) discussed the range of predictions obtained in step 1. Here, we detail the modeller's decisions in accounting for the various processes based on what they learned during the field visit (step 2) and add the final outcome of step 3 when the modellers made use of additional data. We document the prediction progress as well as the learning process resulting from the availability of added information. For the 2nd and 3rd step, the progress in prediction quality could be evaluated in relation to individual modelling experience and costs of added information. We learned (i) that soft information such as the modeller's system understanding is as important as the model itself (hard information), (ii) that the sequence of modelling steps matters (field visit, interactions between differently experienced experts, choice of model, selection of available data, and methods for parameter guessing

  9. Searching for 'Unknown Unknowns'

    NASA Technical Reports Server (NTRS)

    Parsons, Vickie S.

    2005-01-01

    The NASA Engineering and Safety Center (NESC) was established to improve safety through engineering excellence within NASA programs and projects. As part of this goal, methods are being investigated to enable the NESC to become proactive in identifying areas that may be precursors to future problems. The goal is to find unknown indicators of future problems, not to duplicate the program-specific trending efforts. The data that is critical for detecting these indicators exist in a plethora of dissimilar non-conformance and other databases (without a common format or taxonomy). In fact, much of the data is unstructured text. However, one common database is not required if the right standards and electronic tools are employed. Electronic data mining is a particularly promising tool for this effort into unsupervised learning of common factors. This work in progress began with a systematic evaluation of available data mining software packages, based on documented decision techniques using weighted criteria. The four packages, which were perceived to have the most promise for NASA applications, are being benchmarked and evaluated by independent contractors. Preliminary recommendations for "best practices" in data mining and trending are provided. Final results and recommendations should be available in the Fall 2005. This critical first step in identifying "unknown unknowns" before they become problems is applicable to any set of engineering or programmatic data.

  10. Reaction norm model with unknown environmental covariate to analyze heterosis by environment interaction.

    PubMed

    Su, G; Madsen, P; Lund, M S

    2009-05-01

    Crossbreeding is currently increasing in dairy cattle production. Several studies have shown an environment-dependent heterosis [i.e., an interaction between heterosis and environment (H x E)]. An H x E interaction is usually estimated from a few discrete environment levels. The present study proposes a reaction norm model to describe H x E interaction, which can deal with a large number of environment levels using few parameters. In the proposed model, total heterosis consists of an environment-independent part, which is described as a function of heterozygosity, and an environment-dependent part, which is described as a function of heterozygosity and environmental value (e.g., herd-year effect). A Bayesian approach is developed to estimate the environmental covariates, the regression coefficients of the reaction norm, and other parameters of the model simultaneously in both linear and nonlinear reaction norms. In the nonlinear reaction norm model, the H x E is approximated using linear splines. The approach was tested using simulated data, which were generated using an animal model with a reaction norm for heterosis. The simulation study includes 4 scenarios (the combinations of moderate vs. low heritability and moderate vs. low herd-year variation) of H x E interaction in a nonlinear form. In all scenarios, the proposed model predicted total heterosis very well. The correlation between true heterosis and predicted heterosis was 0.98 in the scenarios with low herd-year variation and 0.99 in the scenarios with moderate herd-year variation. This suggests that the proposed model and method could be a good approach to analyze H x E interactions and predict breeding values in situations in which heterosis changes gradually and continuously over an environmental gradient. On the other hand, it was found that a model ignoring H x E interaction did not significantly harm the prediction of breeding value under the simulated scenarios in which the variance for environment

  11. SLAM algorithm applied to robotics assistance for navigation in unknown environments.

    PubMed

    Cheein, Fernando A Auat; Lopez, Natalia; Soria, Carlos M; di Sciascio, Fernando A; Pereira, Fernando Lobo; Carelli, Ricardo

    2010-02-17

    The combination of robotic tools with assistance technology determines a slightly explored area of applications and advantages for disability or elder people in their daily tasks. Autonomous motorized wheelchair navigation inside an environment, behaviour based control of orthopaedic arms or user's preference learning from a friendly interface are some examples of this new field. In this paper, a Simultaneous Localization and Mapping (SLAM) algorithm is implemented to allow the environmental learning by a mobile robot while its navigation is governed by electromyographic signals. The entire system is part autonomous and part user-decision dependent (semi-autonomous). The environmental learning executed by the SLAM algorithm and the low level behaviour-based reactions of the mobile robot are robotic autonomous tasks, whereas the mobile robot navigation inside an environment is commanded by a Muscle-Computer Interface (MCI). In this paper, a sequential Extended Kalman Filter (EKF) feature-based SLAM algorithm is implemented. The features correspond to lines and corners -concave and convex- of the environment. From the SLAM architecture, a global metric map of the environment is derived. The electromyographic signals that command the robot's movements can be adapted to the patient's disabilities. For mobile robot navigation purposes, five commands were obtained from the MCI: turn to the left, turn to the right, stop, start and exit. A kinematic controller to control the mobile robot was implemented. A low level behavior strategy was also implemented to avoid robot's collisions with the environment and moving agents. The entire system was tested in a population of seven volunteers: three elder, two below-elbow amputees and two young normally limbed patients. The experiments were performed within a closed low dynamic environment. Subjects took an average time of 35 minutes to navigate the environment and to learn how to use the MCI. The SLAM results have shown a

  12. SLAM algorithm applied to robotics assistance for navigation in unknown environments

    PubMed Central

    2010-01-01

    Background The combination of robotic tools with assistance technology determines a slightly explored area of applications and advantages for disability or elder people in their daily tasks. Autonomous motorized wheelchair navigation inside an environment, behaviour based control of orthopaedic arms or user's preference learning from a friendly interface are some examples of this new field. In this paper, a Simultaneous Localization and Mapping (SLAM) algorithm is implemented to allow the environmental learning by a mobile robot while its navigation is governed by electromyographic signals. The entire system is part autonomous and part user-decision dependent (semi-autonomous). The environmental learning executed by the SLAM algorithm and the low level behaviour-based reactions of the mobile robot are robotic autonomous tasks, whereas the mobile robot navigation inside an environment is commanded by a Muscle-Computer Interface (MCI). Methods In this paper, a sequential Extended Kalman Filter (EKF) feature-based SLAM algorithm is implemented. The features correspond to lines and corners -concave and convex- of the environment. From the SLAM architecture, a global metric map of the environment is derived. The electromyographic signals that command the robot's movements can be adapted to the patient's disabilities. For mobile robot navigation purposes, five commands were obtained from the MCI: turn to the left, turn to the right, stop, start and exit. A kinematic controller to control the mobile robot was implemented. A low level behavior strategy was also implemented to avoid robot's collisions with the environment and moving agents. Results The entire system was tested in a population of seven volunteers: three elder, two below-elbow amputees and two young normally limbed patients. The experiments were performed within a closed low dynamic environment. Subjects took an average time of 35 minutes to navigate the environment and to learn how to use the MCI. The SLAM

  13. Validating Affordances as an Instrument for Design and a Priori Analysis of Didactical Situations in Mathematics

    ERIC Educational Resources Information Center

    Sollervall, Håkan; Stadler, Erika

    2015-01-01

    The aim of the presented case study is to investigate how coherent analytical instruments may guide the a priori and a posteriori analyses of a didactical situation. In the a priori analysis we draw on the notion of affordances, as artefact-mediated opportunities for action, to construct hypothetical trajectories of goal-oriented actions that have…

  14. Map generation in unknown environments by AUKF-SLAM using line segment-type and point-type landmarks

    NASA Astrophysics Data System (ADS)

    Nishihta, Sho; Maeyama, Shoichi; Watanebe, Keigo

    2018-02-01

    Recently, autonomous mobile robots that collect information at disaster sites are being developed. Since it is difficult to obtain maps in advance in disaster sites, the robots being capable of autonomous movement under unknown environments are required. For this objective, the robots have to build maps, as well as the estimation of self-location. This is called a SLAM problem. In particular, AUKF-SLAM which uses corners in the environment as point-type landmarks has been developed as a solution method so far. However, when the robots move in an environment like a corridor consisting of few point-type features, the accuracy of self-location estimated by the landmark is decreased and it causes some distortions in the map. In this research, we propose AUKF-SLAM which uses walls in the environment as a line segment-type landmark. We demonstrate that the robot can generate maps in unknown environment by AUKF-SLAM, using line segment-type and point-type landmarks.

  15. Optimal quantum cloning based on the maximin principle by using a priori information

    NASA Astrophysics Data System (ADS)

    Kang, Peng; Dai, Hong-Yi; Wei, Jia-Hua; Zhang, Ming

    2016-10-01

    We propose an optimal 1 →2 quantum cloning method based on the maximin principle by making full use of a priori information of amplitude and phase about the general cloned qubit input set, which is a simply connected region enclosed by a "longitude-latitude grid" on the Bloch sphere. Theoretically, the fidelity of the optimal quantum cloning machine derived from this method is the largest in terms of the maximin principle compared with that of any other machine. The problem solving is an optimization process that involves six unknown complex variables, six vectors in an uncertain-dimensional complex vector space, and four equality constraints. Moreover, by restricting the structure of the quantum cloning machine, the optimization problem is simplified as a three-real-parameter suboptimization problem with only one equality constraint. We obtain the explicit formula for a suboptimal quantum cloning machine. Additionally, the fidelity of our suboptimal quantum cloning machine is higher than or at least equal to that of universal quantum cloning machines and phase-covariant quantum cloning machines. It is also underlined that the suboptimal cloning machine outperforms the "belt quantum cloning machine" for some cases.

  16. Use of a priori statistics to minimize acquisition time for RFI immune spread spectrum systems

    NASA Technical Reports Server (NTRS)

    Holmes, J. K.; Woo, K. T.

    1978-01-01

    The optimum acquisition sweep strategy was determined for a PN code despreader when the a priori probability density function was not uniform. A psuedo noise spread spectrum system was considered which could be utilized in the DSN to combat radio frequency interference. In a sample case, when the a priori probability density function was Gaussian, the acquisition time was reduced by about 41% compared to a uniform sweep approach.

  17. Reconstruction of Consistent 3d CAD Models from Point Cloud Data Using a Priori CAD Models

    NASA Astrophysics Data System (ADS)

    Bey, A.; Chaine, R.; Marc, R.; Thibault, G.; Akkouche, S.

    2011-09-01

    We address the reconstruction of 3D CAD models from point cloud data acquired in industrial environments, using a pre-existing 3D model as an initial estimate of the scene to be processed. Indeed, this prior knowledge can be used to drive the reconstruction so as to generate an accurate 3D model matching the point cloud. We more particularly focus our work on the cylindrical parts of the 3D models. We propose to state the problem in a probabilistic framework: we have to search for the 3D model which maximizes some probability taking several constraints into account, such as the relevancy with respect to the point cloud and the a priori 3D model, and the consistency of the reconstructed model. The resulting optimization problem can then be handled using a stochastic exploration of the solution space, based on the random insertion of elements in the configuration under construction, coupled with a greedy management of the conflicts which efficiently improves the configuration at each step. We show that this approach provides reliable reconstructed 3D models by presenting some results on industrial data sets.

  18. Practical interior tomography with radial Hilbert filtering and a priori knowledge in a small round area.

    PubMed

    Tang, Shaojie; Yang, Yi; Tang, Xiangyang

    2012-01-01

    Interior tomography problem can be solved using the so-called differentiated backprojection-projection onto convex sets (DBP-POCS) method, which requires a priori knowledge within a small area interior to the region of interest (ROI) to be imaged. In theory, the small area wherein the a priori knowledge is required can be in any shape, but most of the existing implementations carry out the Hilbert filtering either horizontally or vertically, leading to a vertical or horizontal strip that may be across a large area in the object. In this work, we implement a practical DBP-POCS method with radial Hilbert filtering and thus the small area with the a priori knowledge can be roughly round (e.g., a sinus or ventricles among other anatomic cavities in human or animal body). We also conduct an experimental evaluation to verify the performance of this practical implementation. We specifically re-derive the reconstruction formula in the DBP-POCS fashion with radial Hilbert filtering to assure that only a small round area with the a priori knowledge be needed (namely radial DBP-POCS method henceforth). The performance of the practical DBP-POCS method with radial Hilbert filtering and a priori knowledge in a small round area is evaluated with projection data of the standard and modified Shepp-Logan phantoms simulated by computer, followed by a verification using real projection data acquired by a computed tomography (CT) scanner. The preliminary performance study shows that, if a priori knowledge in a small round area is available, the radial DBP-POCS method can solve the interior tomography problem in a more practical way at high accuracy. In comparison to the implementations of DBP-POCS method demanding the a priori knowledge in horizontal or vertical strip, the radial DBP-POCS method requires the a priori knowledge within a small round area only. Such a relaxed requirement on the availability of a priori knowledge can be readily met in practice, because a variety of small

  19. Conventional Principles in Science: On the foundations and development of the relativized a priori

    NASA Astrophysics Data System (ADS)

    Ivanova, Milena; Farr, Matt

    2015-11-01

    The present volume consists of a collection of papers originally presented at the conference Conventional Principles in Science, held at the University of Bristol, August 2011, which featured contributions on the history and contemporary development of the notion of 'relativized a priori' principles in science, from Henri Poincaré's conventionalism to Michael Friedman's contemporary defence of the relativized a priori. In Science and Hypothesis, Poincaré assessed the problematic epistemic status of Euclidean geometry and Newton's laws of motion, famously arguing that each has the status of 'convention' in that their justification is neither analytic nor empirical in nature. In The Theory of Relativity and A Priori Knowledge, Hans Reichenbach, in light of the general theory of relativity, proposed an updated notion of the Kantian synthetic a priori to account for the dynamic inter-theoretic status of geometry and other non-empirical physical principles. Reichenbach noted that one may reject the 'necessarily true' aspect of the synthetic a priori whilst preserving the feature of being constitutive of the object of knowledge. Such constitutive principles are theory-relative, as illustrated by the privileged role of non-Euclidean geometry in general relativity theory. This idea of relativized a priori principles in spacetime physics has been analysed and developed at great length in the modern literature in the work of Michael Friedman, in particular the roles played by the light postulate and the equivalence principle - in special and general relativity respectively - in defining the central terms of their respective theories and connecting the abstract mathematical formalism of the theories with their empirical content. The papers in this volume guide the reader through the historical development of conventional and constitutive principles in science, from the foundational work of Poincaré, Reichenbach and others, to contemporary issues and applications of the

  20. The constitutive a priori and the distinction between mathematical and physical possibility

    NASA Astrophysics Data System (ADS)

    Everett, Jonathan

    2015-11-01

    This paper is concerned with Friedman's recent revival of the notion of the relativized a priori. It is particularly concerned with addressing the question as to how Friedman's understanding of the constitutive function of the a priori has changed since his defence of the idea in his Dynamics of Reason. Friedman's understanding of the a priori remains influenced by Reichenbach's initial defence of the idea; I argue that this notion of the a priori does not naturally lend itself to describing the historical development of space-time physics. Friedman's analysis of the role of the rotating frame thought experiment in the development of general relativity - which he suggests made the mathematical possibility of four-dimensional space-time a genuine physical possibility - has a central role in his argument. I analyse this thought experiment and argue that it is better understood by following Cassirer and placing emphasis on regulative principles. Furthermore, I argue that Cassirer's Kantian framework enables us to capture Friedman's key insights into the nature of the constitutive a priori.

  1. Mediterranean Diet and Cardiovascular Disease: A Critical Evaluation of A Priori Dietary Indexes

    PubMed Central

    D’Alessandro, Annunziata; De Pergola, Giovanni

    2015-01-01

    The aim of this paper is to analyze the a priori dietary indexes used in the studies that have evaluated the role of the Mediterranean Diet in influencing the risk of developing cardiovascular disease. All the studies show that this dietary pattern protects against cardiovascular disease, but studies show quite different effects on specific conditions such as coronary heart disease or cerebrovascular disease. A priori dietary indexes used to measure dietary exposure imply quantitative and/or qualitative divergences from the traditional Mediterranean Diet of the early 1960s, and, therefore, it is very difficult to compare the results of different studies. Based on real cultural heritage and traditions, we believe that the a priori indexes used to evaluate adherence to the Mediterranean Diet should consider classifying whole grains and refined grains, olive oil and monounsaturated fats, and wine and alcohol differently. PMID:26389950

  2. Inverse identification of unknown finite-duration air pollutant release from a point source in urban environment

    NASA Astrophysics Data System (ADS)

    Kovalets, Ivan V.; Efthimiou, George C.; Andronopoulos, Spyros; Venetsanos, Alexander G.; Argyropoulos, Christos D.; Kakosimos, Konstantinos E.

    2018-05-01

    In this work, we present an inverse computational method for the identification of the location, start time, duration and quantity of emitted substance of an unknown air pollution source of finite time duration in an urban environment. We considered a problem of transient pollutant dispersion under stationary meteorological fields, which is a reasonable assumption for the assimilation of available concentration measurements within 1 h from the start of an incident. We optimized the calculation of the source-receptor function by developing a method which requires integrating as many backward adjoint equations as the available measurement stations. This resulted in high numerical efficiency of the method. The source parameters are computed by maximizing the correlation function of the simulated and observed concentrations. The method has been integrated into the CFD code ADREA-HF and it has been tested successfully by performing a series of source inversion runs using the data of 200 individual realizations of puff releases, previously generated in a wind tunnel experiment.

  3. Phase estimation without a priori phase knowledge in the presence of loss

    SciTech Connect

    Kolodynski, Jan; Demkowicz-Dobrzanski, Rafal

    2010-11-15

    We find the optimal scheme for quantum phase estimation in the presence of loss when no a priori knowledge on the estimated phase is available. We prove analytically an explicit lower bound on estimation uncertainty, which shows that, as a function of the number of probes, quantum precision enhancement amounts at most to a constant factor improvement over classical strategies.

  4. Realism, functions, and the a priori: Ernst Cassirer's philosophy of science.

    PubMed

    Heis, Jeremy

    2014-12-01

    This paper presents the main ideas of Cassirer's general philosophy of science, focusing on the two aspects of his thought that--in addition to being the most central ideas in his philosophy of science--have received the most attention from contemporary philosophers of science: his theory of the a priori aspects of physical theory, and his relation to scientific realism.

  5. A single footshock causes long-lasting hypoactivity in unknown environments that is dependent on the development of contextual fear conditioning.

    PubMed

    Daviu, Núria; Fuentes, Silvia; Nadal, Roser; Armario, Antonio

    2010-09-01

    Exposure to a single session of footshocks induces long-lasting inhibition of activity in unknown environments that markedly differ from the shock context. Interestingly, these effects are not necessarily associated to an enhanced anxiety and interpretation of this hypoactivity remains unclear. In the present experiment we further studied this phenomenon in male Sprague-Dawley rats. In a first experiment, a session of three shocks resulted in hypoactivity during exposure, 6-12days later, to three different unknown environments. This altered behaviour was not accompanied by a greater hypothalamic-pituitary-adrenal (HPA) activation, although greater HPA activation paralleling higher levels of freezing was observed in the shock context. In a second experiment we used a single shock and two procedures, one with pre-exposure to the context before the shock and another with immediate shock that did not induce contextual fear conditioning. Hypoactivity and a certain level of generalization of fear (freezing) to the unknown environments only appeared in the group that developed fear conditioning, but no evidence for enhanced anxiety in the elevated plus-maze was found in any group. The results suggest that if animals are able to associate an aversive experience with a distinct unknown environment, they would display more cautious behaviour in any unknown environment and such strategy persists despite repeated experience with different environments. This long-lasting cautious behaviour was not associated to greater HPA response to the unknown environment that was however observed in the shock context. The present findings raised some concerns about interpretation of long-lasting behavioural changes caused by brief stressors. Copyright 2010 Elsevier Inc. All rights reserved.

  6. Global a priori estimates for the inhomogeneous Landau equation with moderately soft potentials

    NASA Astrophysics Data System (ADS)

    Cameron, Stephen; Silvestre, Luis; Snelson, Stanley

    2018-05-01

    We establish a priori upper bounds for solutions to the spatially inhomogeneous Landau equation in the case of moderately soft potentials, with arbitrary initial data, under the assumption that mass, energy and entropy densities stay under control. Our pointwise estimates decay polynomially in the velocity variable. We also show that if the initial data satisfies a Gaussian upper bound, this bound is propagated for all positive times.

  7. Effects of daily, high spatial resolution a priori profiles of satellite-derived NOx emissions

    NASA Astrophysics Data System (ADS)

    Laughner, J.; Zare, A.; Cohen, R. C.

    2016-12-01

    The current generation of space-borne NO2 column observations provides a powerful method of constraining NOx emissions due to the spatial resolution and global coverage afforded by the Ozone Monitoring Instrument (OMI). The greater resolution available in next generation instruments such as TROPOMI and the capabilities of geosynchronous platforms TEMPO, Sentinel-4, and GEMS will provide even greater capabilities in this regard, but we must apply lessons learned from the current generation of retrieval algorithms to make the best use of these instruments. Here, we focus on the effect of the resolution of the a priori NO2 profiles used in the retrieval algorithms. We show that for an OMI retrieval, using daily high-resolution a priori profiles results in changes in the retrieved VCDs up to 40% when compared to a retrieval using monthly average profiles at the same resolution. Further, comparing a retrieval with daily high spatial resolution a priori profiles to a more standard one, we show that emissions derived increase by 100% when using the optimized retrieval.

  8. Implications of genome wide association studies for addiction: are our a priori assumptions all wrong?

    PubMed

    Hall, F Scott; Drgonova, Jana; Jain, Siddharth; Uhl, George R

    2013-12-01

    Substantial genetic contributions to addiction vulnerability are supported by data from twin studies, linkage studies, candidate gene association studies and, more recently, Genome Wide Association Studies (GWAS). Parallel to this work, animal studies have attempted to identify the genes that may contribute to responses to addictive drugs and addiction liability, initially focusing upon genes for the targets of the major drugs of abuse. These studies identified genes/proteins that affect responses to drugs of abuse; however, this does not necessarily mean that variation in these genes contributes to the genetic component of addiction liability. One of the major problems with initial linkage and candidate gene studies was an a priori focus on the genes thought to be involved in addiction based upon the known contributions of those proteins to drug actions, making the identification of novel genes unlikely. The GWAS approach is systematic and agnostic to such a priori assumptions. From the numerous GWAS now completed several conclusions may be drawn: (1) addiction is highly polygenic; each allelic variant contributing in a small, additive fashion to addiction vulnerability; (2) unexpected, compared to our a priori assumptions, classes of genes are most important in explaining addiction vulnerability; (3) although substantial genetic heterogeneity exists, there is substantial convergence of GWAS signals on particular genes. This review traces the history of this research; from initial transgenic mouse models based upon candidate gene and linkage studies, through the progression of GWAS for addiction and nicotine cessation, to the current human and transgenic mouse studies post-GWAS. © 2013.

  9. The Mediterranean Diet: its definition and evaluation of a priori dietary indexes in primary cardiovascular prevention.

    PubMed

    D'Alessandro, Annunziata; De Pergola, Giovanni

    2018-01-18

    We have analysed the definition of Mediterranean Diet in 28 studies included in six meta-analyses evaluating the relation between the Mediterranean Diet and primary prevention of cardiovascular disease. Some typical food of this dietary pattern like whole cereals, olive oil and red wine were taken into account only in a few a priori indexes, and the dietary pattern defined as Mediterranean showed many differences among the studies and compared to traditional Mediterranean Diet of the early 1960s. Altogether, the analysed studies show a protective effect of the Mediterranean Diet against cardiovascular disease but present different effects against specific conditions as cerebrovascular disease and coronary heart disease. These different effects might depend on the definition of Mediterranean Diet and the indexes of the adhesion to the same one used. To compare the effects of the Mediterranean Diet against cardiovascular disease, coronary heart disease and stroke a univocal model of Mediterranean Diet should be established as a reference, and it might be represented by the Modern Mediterranean Diet Pyramid. The a priori index to evaluate the adhesion to Mediterranean Diet might be the Mediterranean-Style Dietary Pattern Score that has some advantages in comparison to the others a priori indexes.

  10. Geopositioning with a quadcopter: Extracted feature locations and predicted accuracy without a priori sensor attitude information

    NASA Astrophysics Data System (ADS)

    Dolloff, John; Hottel, Bryant; Edwards, David; Theiss, Henry; Braun, Aaron

    2017-05-01

    This paper presents an overview of the Full Motion Video-Geopositioning Test Bed (FMV-GTB) developed to investigate algorithm performance and issues related to the registration of motion imagery and subsequent extraction of feature locations along with predicted accuracy. A case study is included corresponding to a video taken from a quadcopter. Registration of the corresponding video frames is performed without the benefit of a priori sensor attitude (pointing) information. In particular, tie points are automatically measured between adjacent frames using standard optical flow matching techniques from computer vision, an a priori estimate of sensor attitude is then computed based on supplied GPS sensor positions contained in the video metadata and a photogrammetric/search-based structure from motion algorithm, and then a Weighted Least Squares adjustment of all a priori metadata across the frames is performed. Extraction of absolute 3D feature locations, including their predicted accuracy based on the principles of rigorous error propagation, is then performed using a subset of the registered frames. Results are compared to known locations (check points) over a test site. Throughout this entire process, no external control information (e.g. surveyed points) is used other than for evaluation of solution errors and corresponding accuracy.

  11. A priori mesh grading for the numerical calculation of the head-related transfer functions

    PubMed Central

    Ziegelwanger, Harald; Kreuzer, Wolfgang; Majdak, Piotr

    2017-01-01

    Head-related transfer functions (HRTFs) describe the directional filtering of the incoming sound caused by the morphology of a listener’s head and pinnae. When an accurate model of a listener’s morphology exists, HRTFs can be calculated numerically with the boundary element method (BEM). However, the general recommendation to model the head and pinnae with at least six elements per wavelength renders the BEM as a time-consuming procedure when calculating HRTFs for the full audible frequency range. In this study, a mesh preprocessing algorithm is proposed, viz., a priori mesh grading, which reduces the computational costs in the HRTF calculation process significantly. The mesh grading algorithm deliberately violates the recommendation of at least six elements per wavelength in certain regions of the head and pinnae and varies the size of elements gradually according to an a priori defined grading function. The evaluation of the algorithm involved HRTFs calculated for various geometric objects including meshes of three human listeners and various grading functions. The numerical accuracy and the predicted sound-localization performance of calculated HRTFs were analyzed. A-priori mesh grading appeared to be suitable for the numerical calculation of HRTFs in the full audible frequency range and outperformed uniform meshes in terms of numerical errors, perception based predictions of sound-localization performance, and computational costs. PMID:28239186

  12. Approximate deconvolution model for the simulation of turbulent gas-solid flows: An a priori analysis

    NASA Astrophysics Data System (ADS)

    Schneiderbauer, Simon; Saeedipour, Mahdi

    2018-02-01

    Highly resolved two-fluid model (TFM) simulations of gas-solid flows in vertical periodic channels have been performed to study closures for the filtered drag force and the Reynolds-stress-like contribution stemming from the convective terms. An approximate deconvolution model (ADM) for the large-eddy simulation of turbulent gas-solid suspensions is detailed and subsequently used to reconstruct those unresolved contributions in an a priori manner. With such an approach, an approximation of the unfiltered solution is obtained by repeated filtering allowing the determination of the unclosed terms of the filtered equations directly. A priori filtering shows that predictions of the ADM model yield fairly good agreement with the fine grid TFM simulations for various filter sizes and different particle sizes. In particular, strong positive correlation (ρ > 0.98) is observed at intermediate filter sizes for all sub-grid terms. Additionally, our study reveals that the ADM results moderately depend on the choice of the filters, such as box and Gaussian filter, as well as the deconvolution order. The a priori test finally reveals that ADM is superior compared to isotropic functional closures proposed recently [S. Schneiderbauer, "A spatially-averaged two-fluid model for dense large-scale gas-solid flows," AIChE J. 63, 3544-3562 (2017)].

  13. Impact of a priori information on IASI ozone retrievals and trends

    NASA Astrophysics Data System (ADS)

    Barret, B.; Peiro, H.; Emili, E.; Le Flocgmoën, E.

    2017-12-01

    The IASI sensor documents atmospheric water vapor, temperature and composition since 2007. The Software for a Fast Retrieval of IASI Data (SOFRID) has been developped to retrieve O3 and CO profiles from IASI in near-real time on a global scale. Information content analyses have shown that IASI enables the quantification of O3 independently in the troposphere, the UTLS and the stratosphere. Validation studies have demonstrated that the daily to seasonal variability of tropospheric and UTLS O3 was well captured by IASI especially in the tropics. IASI-SOFRID retrievals have also been used to document the tropospheric composition during the Asian monsoon and participated to determine the O3 evolution during the 2008-2016 period in the framework of the TOAR project. Nevertheless, IASI-SOFRID O3 is biased high in the UTLS and in the tropical troposphere and the 8 years O3 trends from the different IASI products are significantly different from the O3 trends from UV-Vis satellite sensors (e.g. OMI)..SOFRID is based on the Optimal Estimation Method that requires a priori information to complete the information provided by the measured thermal infrared radiances. In SOFRID-O3 v1.5 used in TOAR the a priori consists of a single O3 profile and associated covariance matrix based on global O3 radiosoundings. Such a global a priori is characterized by a very large variabilty and does not represent our best kowledge of the O3 profile at a given time and location. Furthermore it is biased towards the northern hemisphere middle latitudes. We have therefore implemented the possibility to use dynamical a priori data in SOFRID and performed experiments using O3 climatological data and MLS O3 analyses. We will present O3 distributions and comparisons with O3 radiosoundings from the different SOFRID-O3 retrievals. We will in particular assess the impact of the use of different a priori data upon the O3 biases and trends during the IASI period.

  14. A methodology for the generation of the 2-D map from unknown navigation environment by traveling a short distance

    NASA Technical Reports Server (NTRS)

    Bourbakis, N.; Sarkar, D.

    1994-01-01

    A technique for generation of a 2-D space map by traveling a short distance is described. The space to be mapped can be classified as: (1) space without obstacles, (2) space with stationary obstacles, and (3) space with moving obstacles. This paper presents the methodology used to generate a 2-D map of an unknown navigation space. The ability to minimize the redundancy during traveling and maximize the confidence function for generation of the map are advantages of this technique.

  15. Evaluating A Priori Ozone Profile Information Used in TEMPO Tropospheric Ozone Retrievals

    NASA Astrophysics Data System (ADS)

    Johnson, M. S.; Sullivan, J. T.; Liu, X.; Newchurch, M.; Kuang, S.; McGee, T. J.; Langford, A. O.; Senff, C. J.; Leblanc, T.; Berkoff, T.; Gronoff, G.; Chen, G.; Strawbridge, K. B.

    2016-12-01

    Ozone (O3) is a greenhouse gas and toxic pollutant which plays a major role in air quality. Typically, monitoring of surface air quality and O3 mixing ratios is primarily conducted using in situ measurement networks. This is partially due to high-quality information related to air quality being limited from space-borne platforms due to coarse spatial resolution, limited temporal frequency, and minimal sensitivity to lower tropospheric and surface-level O3. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) satellite is designed to address these limitations of current space-based platforms and to improve our ability to monitor North American air quality. TEMPO will provide hourly data of total column and vertical profiles of O3 with high spatial resolution to be used as a near-real-time air quality product. TEMPO O3 retrievals will apply the Smithsonian Astrophysical Observatory profile algorithm developed based on work from GOME, GOME-2, and OMI. This algorithm uses a priori O3 profile information from a climatological data-base developed from long-term ozone-sonde measurements (tropopause-based (TB) O3 climatology). It has been shown that satellite O3 retrievals are sensitive to a priori O3 profiles and covariance matrices. During this work we investigate the climatological data to be used in TEMPO algorithms (TB O3) and simulated data from the NASA GMAO Goddard Earth Observing System (GEOS-5) Forward Processing (FP) near-real-time (NRT) model products. These two data products will be evaluated with ground-based lidar data from the Tropospheric Ozone Lidar Network (TOLNet) at various locations of the US. This study evaluates the TB climatology, GEOS-5 climatology, and 3-hourly GEOS-5 data compared to lower tropospheric observations to demonstrate the accuracy of a priori information to potentially be used in TEMPO O3 algorithms. Here we present our initial analysis and the theoretical impact on TEMPO retrievals in the lower troposphere.

  16. An a priori solar radiation pressure model for the QZSS Michibiki satellite

    NASA Astrophysics Data System (ADS)

    Zhao, Qile; Chen, Guo; Guo, Jing; Liu, Jingnan; Liu, Xianglin

    2018-02-01

    It has been noted that the satellite laser ranging (SLR) residuals of the Quasi-Zenith Satellite System (QZSS) Michibiki satellite orbits show very marked dependence on the elevation angle of the Sun above the orbital plane (i.e., the β angle). It is well recognized that the systematic error is caused by mismodeling of the solar radiation pressure (SRP). Although the error can be reduced by the updated ECOM SRP model, the orbit error is still very large when the satellite switches to orbit-normal (ON) orientation. In this study, an a priori SRP model was established for the QZSS Michibiki satellite to enhance the ECOM model. This model is expressed in ECOM's D, Y, and B axes (DYB) using seven parameters for the yaw-steering (YS) mode, and additional three parameters are used to compensate the remaining modeling deficiencies, particularly the perturbations in the Y axis, based on a redefined DYB for the ON mode. With the proposed a priori model, QZSS Michibiki's precise orbits over 21 months were determined. SLR validation indicated that the systematic β -angle-dependent error was reduced when the satellite was in the YS mode, and better than an 8-cm root mean square (RMS) was achieved. More importantly, the orbit quality was also improved significantly when the satellite was in the ON mode. Relative to ECOM and adjustable box-wing model, the proposed SRP model showed the best performance in the ON mode, and the RMS of the SLR residuals was better than 15 cm, which was a two times improvement over the ECOM without a priori model used, but was still two times worse than the YS mode.

  17. Evaluating A Priori Ozone Profile Information Used in TEMPO Tropospheric Ozone Retrievals

    NASA Technical Reports Server (NTRS)

    Johnson, Matthew S.; Sullivan, John T.; Liu, Xiong; Newchurch, Mike; Kuang, Shi; McGee, Thomas J.; Langford, Andrew O'Neil; Senff, Christoph J.; Leblanc, Thierry; Berkoff, Timothy; hide

    2016-01-01

    Ozone (O3) is a greenhouse gas and toxic pollutant which plays a major role in air quality. Typically, monitoring of surface air quality and O3 mixing ratios is primarily conducted using in situ measurement networks. This is partially due to high-quality information related to air quality being limited from space-borne platforms due to coarse spatial resolution, limited temporal frequency, and minimal sensitivity to lower tropospheric and surface-level O3. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) satellite is designed to address these limitations of current space-based platforms and to improve our ability to monitor North American air quality. TEMPO will provide hourly data of total column and vertical profiles of O3 with high spatial resolution to be used as a near-real-time air quality product. TEMPO O3 retrievals will apply the Smithsonian Astrophysical Observatory profile algorithm developed based on work from GOME, GOME-2, and OMI. This algorithm uses a priori O3 profile information from a climatological data-base developed from long-term ozone-sonde measurements (tropopause-based (TB) O3 climatology). It has been shown that satellite O3 retrievals are sensitive to a priori O3 profiles and covariance matrices. During this work we investigate the climatological data to be used in TEMPO algorithms (TB O3) and simulated data from the NASA GMAO Goddard Earth Observing System (GEOS-5) Forward Processing (FP) near-real-time (NRT) model products. These two data products will be evaluated with ground-based lidar data from the Tropospheric Ozone Lidar Network (TOLNet) at various locations of the US. This study evaluates the TB climatology, GEOS-5 climatology, and 3-hourly GEOS-5 data compared to lower tropospheric observations to demonstrate the accuracy of a priori information to potentially be used in TEMPO O3 algorithms. Here we present our initial analysis and the theoretical impact on TEMPO retrievals in the lower troposphere.

  18. Evaluating a Priori Ozone Profile Information Used in TEMPO Tropospheric Ozone Retrievals

    NASA Technical Reports Server (NTRS)

    Johnson, Matthew S.; Sullivan, John; Liu, Xiong; Newchurch, Mike; Kuang, Shi; McGee, Thomas; Langford, Andrew; Senff, Chris; Leblanc, Thierry; Berkoff, Timothy; hide

    2016-01-01

    Ozone (O3) is a greenhouse gas and toxic pollutant which plays a major role in air quality. Typically, monitoring of surface air quality and O3 mixing ratios is primarily conducted using in situ measurement networks. This is partially due to high-quality information related to air quality being limited from space-borne platforms due to coarse spatial resolution, limited temporal frequency, and minimal sensitivity to lower tropospheric and surface-level O3. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) satellite is designed to address these limitations of current space-based platforms and to improve our ability to monitor North American air quality. TEMPO will provide hourly data of total column and vertical profiles of O3 with high spatial resolution to be used as a near-real-time air quality product.TEMPO O3 retrievals will apply the Smithsonian Astrophysical Observatory profile algorithm developed based on work from GOME, GOME-2, and OMI. This algorithm uses a priori O3 profile information from a climatological data-base developed from long-term ozone-sonde measurements (tropopause-based (TB) O3 climatology). It has been shown that satellite O3 retrievals are sensitive to a priori O3 profiles and covariance matrices. During this work we investigate the climatological data to be used in TEMPO algorithms (TB O3) and simulated data from the NASA GMAO Goddard Earth Observing System (GEOS-5) Forward Processing (FP) near-real-time (NRT) model products. These two data products will be evaluated with ground-based lidar data from the Tropospheric Ozone Lidar Network (TOLNet) at various locations of the US. This study evaluates the TB climatology, GEOS-5 climatology, and 3-hourly GEOS-5 data compared to lower tropospheric observations to demonstrate the accuracy of a priori information to potentially be used in TEMPO O3 algorithms. Here we present our initial analysis and the theoretical impact on TEMPO retrievals in the lower troposphere.

  19. Importance of A Priori Vertical Ozone Profiles for TEMPO Air Quality Retrievals

    NASA Astrophysics Data System (ADS)

    Johnson, M. S.; Sullivan, J. T.; Liu, X.; Zoogman, P.; Newchurch, M.; Kuang, S.; McGee, T. J.; Leblanc, T.

    2017-12-01

    Ozone (O3) is a toxic pollutant which plays a major role in air quality. Typically, monitoring of surface air quality and O3 mixing ratios is conducted using in situ measurement networks. This is partially due to high-quality information related to air quality being limited from space-borne platforms due to coarse spatial resolution, limited temporal frequency, and minimal sensitivity to lower tropospheric and surface-level O3. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) satellite is designed to address the limitations of current space-based platforms and to improve our ability to monitor North American air quality. TEMPO will provide hourly data of total column and vertical profiles of O3 with high spatial resolution to be used as a near-real-time air quality product. TEMPO O3 retrievals will apply the Smithsonian Astrophysical Observatory profile algorithm developed based on work from GOME, GOME-2, and OMI. This algorithm is suggested to use a priori O3 profile information from a climatological data-base developed from long-term ozone-sonde measurements (tropopause-based (TB-Clim) O3 climatology). This study evaluates the TB-Clim dataset and model simulated O3 profiles, which could potentially serve as a priori O3 profile information in TEMPO retrievals, from near-real-time data assimilation model products (NASA GMAO's operational GEOS-5 FP model and reanalysis data from MERRA2) and a full chemical transport model (CTM), GEOS-Chem. In this study, vertical profile products are evaluated with surface (0-2 km) and tropospheric (0-10 km) TOLNet observations and the theoretical impact of individual a priori profile sources on the accuracy of TEMPO O3 retrievals in the troposphere and at the surface are presented. Results indicate that while the TB-Clim climatological dataset can replicate seasonally-averaged tropospheric O3 profiles, model-simulated profiles from a full CTM resulted in more accurate tropospheric and surface-level O3 retrievals from

  20. Importance of a Priori Vertical Ozone Profiles for TEMPO Air Quality Retrievals

    NASA Technical Reports Server (NTRS)

    Johnson, Matthew S.; Sullivan, John; Liu, Xiong; Zoogman, Peter; Newchurch, Mike; Kuang, Shi; McGee, Thomas; Leblanc, Thierry

    2017-01-01

    Ozone (O3) is a toxic pollutant which plays a major role in air quality. Typically, monitoring of surface air quality and O3 mixing ratios is conducted using in situ measurement networks. This is partially due to high-quality information related to air quality being limited from space-borne platforms due to coarse spatial resolution, limited temporal frequency, and minimal sensitivity to lower tropospheric and surface-level O3. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) satellite is designed to address the limitations of current space-based platforms and to improve our ability to monitor North American air quality. TEMPO will provide hourly data of total column and vertical profiles of O3 with high spatial resolution to be used as a near-real-time air quality product. TEMPO O3 retrievals will apply the Smithsonian Astrophysical Observatory profile algorithm developed based on work from GOME (Global Ozone Monitoring Experiment), GOME-2, and OMI (Ozone Monitoring Instrument). This algorithm is suggested to use a priori O3 profile information from a climatological data-base developed from long-term ozone-sonde measurements (tropopause-based (TB-Clim) O3 climatology). This study evaluates the TB-Clim dataset and model simulated O3 profiles, which could potentially serve as a priori O3 profile information in TEMPO retrievals, from near-real-time data assimilation model products (NASA GMAO's (Global Modeling and Assimilation Office) operational GEOS-5 (Goddard Earth Observing System, Version 5) FP (Forecast Products) model and reanalysis data from MERRA2 (Modern-Era Retrospective analysis for Research and Applications, Version 2)) and a full chemical transport model (CTM), GEOS-Chem. In this study, vertical profile products are evaluated with surface (0-2 kilometers) and tropospheric (0-10 kilometers) TOLNet (Tropospheric Ozone Lidar Network) observations and the theoretical impact of individual a priori profile sources on the accuracy of TEMPO O3

  1. Visual identification and similarity measures used for on-line motion planning of autonomous robots in unknown environments

    NASA Astrophysics Data System (ADS)

    Martínez, Fredy; Martínez, Fernando; Jacinto, Edwar

    2017-02-01

    In this paper we propose an on-line motion planning strategy for autonomous robots in dynamic and locally observable environments. In this approach, we first visually identify geometric shapes in the environment by filtering images. Then, an ART-2 network is used to establish the similarity between patterns. The proposed algorithm allows that a robot establish its relative location in the environment, and define its navigation path based on images of the environment and its similarity to reference images. This is an efficient and minimalist method that uses the similarity of landmark view patterns to navigate to the desired destination. Laboratory tests on real prototypes demonstrate the performance of the algorithm.

  2. Determining the depth of certain gravity sources without a priori specification of their structural index

    NASA Astrophysics Data System (ADS)

    Zhou, Shuai; Huang, Danian

    2015-11-01

    We have developed a new method for the interpretation of gravity tensor data based on the generalized Tilt-depth method. Cooper (2011, 2012) extended the magnetic Tilt-depth method to gravity data. We take the gradient-ratio method of Cooper (2011, 2012) and modify it so that the source type does not need to be specified a priori. We develop the new method by generalizing the Tilt-depth method for depth estimation for different types of source bodies. The new technique uses only the three vertical tensor components of the full gravity tensor data observed or calculated at different height plane to estimate the depth of the buried bodies without a priori specification of their structural index. For severely noise-corrupted data, our method utilizes different upward continuation height data, which can effectively reduce the influence of noise. Theoretical simulations of the gravity source model with and without noise illustrate the ability of the method to provide source depth information. Additionally, the simulations demonstrate that the new method is simple, computationally fast and accurate. Finally, we apply the method using the gravity data acquired over the Humble Salt Dome in the USA as an example. The results show a good correspondence to the previous drilling and seismic interpretation results.

  3. An a priori study of different tabulation methods for turbulent pulverised coal combustion

    NASA Astrophysics Data System (ADS)

    Luo, Yujuan; Wen, Xu; Wang, Haiou; Luo, Kun; Jin, Hanhui; Fan, Jianren

    2018-05-01

    In many practical pulverised coal combustion systems, different oxidiser streams exist, e.g. the primary- and secondary-air streams in the power plant boilers, which makes the modelling of these systems challenging. In this work, three tabulation methods for modelling pulverised coal combustion are evaluated through an a priori study. Pulverised coal flames stabilised in a three-dimensional turbulent counterflow, consisting of different oxidiser streams, are simulated with detailed chemistry first. Then, the thermo-chemical quantities calculated with different tabulation methods are compared to those from detailed chemistry solutions. The comparison shows that the conventional two-stream flamelet model with a fixed oxidiser temperature cannot predict the flame temperature correctly. The conventional two-stream flamelet model is then modified to set the oxidiser temperature equal to the fuel temperature, both of which are varied in the flamelets. By this means, the variations of oxidiser temperature can be considered. It is found that this modified tabulation method performs very well on prediction of the flame temperature. The third tabulation method is an extended three-stream flamelet model that was initially proposed for gaseous combustion. The results show that the reference gaseous temperature profile can be overall reproduced by the extended three-stream flamelet model. Interestingly, it is found that the predictions of major species mass fractions are not sensitive to the oxidiser temperature boundary conditions for the flamelet equations in the a priori analyses.

  4. The a priori SDR Estimation Techniques with Reduced Speech Distortion for Acoustic Echo and Noise Suppression

    NASA Astrophysics Data System (ADS)

    Thoonsaengngam, Rattapol; Tangsangiumvisai, Nisachon

    This paper proposes an enhanced method for estimating the a priori Signal-to-Disturbance Ratio (SDR) to be employed in the Acoustic Echo and Noise Suppression (AENS) system for full-duplex hands-free communications. The proposed a priori SDR estimation technique is modified based upon the Two-Step Noise Reduction (TSNR) algorithm to suppress the background noise while preserving speech spectral components. In addition, a practical approach to determine accurately the Echo Spectrum Variance (ESV) is presented based upon the linear relationship assumption between the power spectrum of far-end speech and acoustic echo signals. The ESV estimation technique is then employed to alleviate the acoustic echo problem. The performance of the AENS system that employs these two proposed estimation techniques is evaluated through the Echo Attenuation (EA), Noise Attenuation (NA), and two speech distortion measures. Simulation results based upon real speech signals guarantee that our improved AENS system is able to mitigate efficiently the problem of acoustic echo and background noise, while preserving the speech quality and speech intelligibility.

  5. Normalization of T2W-MRI prostate images using Rician a priori

    NASA Astrophysics Data System (ADS)

    Lemaître, Guillaume; Rastgoo, Mojdeh; Massich, Joan; Vilanova, Joan C.; Walker, Paul M.; Freixenet, Jordi; Meyer-Baese, Anke; Mériaudeau, Fabrice; Martí, Robert

    2016-03-01

    Prostate cancer is reported to be the second most frequently diagnosed cancer of men in the world. In practise, diagnosis can be affected by multiple factors which reduces the chance to detect the potential lesions. In the last decades, new imaging techniques mainly based on MRI are developed in conjunction with Computer-Aided Diagnosis (CAD) systems to help radiologists for such diagnosis. CAD systems are usually designed as a sequential process consisting of four stages: pre-processing, segmentation, registration and classification. As a pre-processing, image normalization is a critical and important step of the chain in order to design a robust classifier and overcome the inter-patients intensity variations. However, little attention has been dedicated to the normalization of T2W-Magnetic Resonance Imaging (MRI) prostate images. In this paper, we propose two methods to normalize T2W-MRI prostate images: (i) based on a Rician a priori and (ii) based on a Square-Root Slope Function (SRSF) representation which does not make any assumption regarding the Probability Density Function (PDF) of the data. A comparison with the state-of-the-art methods is also provided. The normalization of the data is assessed by comparing the alignment of the patient PDFs in both qualitative and quantitative manners. In both evaluation, the normalization using Rician a priori outperforms the other state-of-the-art methods.

  6. Template based rotation: A method for functional connectivity analysis with a priori templates☆

    PubMed Central

    Schultz, Aaron P.; Chhatwal, Jasmeer P.; Huijbers, Willem; Hedden, Trey; van Dijk, Koene R.A.; McLaren, Donald G.; Ward, Andrew M.; Wigman, Sarah; Sperling, Reisa A.

    2014-01-01

    Functional connectivity magnetic resonance imaging (fcMRI) is a powerful tool for understanding the network level organization of the brain in research settings and is increasingly being used to study large-scale neuronal network degeneration in clinical trial settings. Presently, a variety of techniques, including seed-based correlation analysis and group independent components analysis (with either dual regression or back projection) are commonly employed to compute functional connectivity metrics. In the present report, we introduce template based rotation,1 a novel analytic approach optimized for use with a priori network parcellations, which may be particularly useful in clinical trial settings. Template based rotation was designed to leverage the stable spatial patterns of intrinsic connectivity derived from out-of-sample datasets by mapping data from novel sessions onto the previously defined a priori templates. We first demonstrate the feasibility of using previously defined a priori templates in connectivity analyses, and then compare the performance of template based rotation to seed based and dual regression methods by applying these analytic approaches to an fMRI dataset of normal young and elderly subjects. We observed that template based rotation and dual regression are approximately equivalent in detecting fcMRI differences between young and old subjects, demonstrating similar effect sizes for group differences and similar reliability metrics across 12 cortical networks. Both template based rotation and dual-regression demonstrated larger effect sizes and comparable reliabilities as compared to seed based correlation analysis, though all three methods yielded similar patterns of network differences. When performing inter-network and sub-network connectivity analyses, we observed that template based rotation offered greater flexibility, larger group differences, and more stable connectivity estimates as compared to dual regression and seed based

  7. Self-organized multi-camera network for a fast and easy deployment of ubiquitous robots in unknown environments.

    PubMed

    Canedo-Rodriguez, Adrián; Iglesias, Roberto; Regueiro, Carlos V; Alvarez-Santos, Victor; Pardo, Xose Manuel

    2012-12-27

    To bring cutting edge robotics from research centres to social environments, the robotics community must start providing affordable solutions: the costs must be reduced and the quality and usefulness of the robot services must be enhanced. Unfortunately, nowadays the deployment of robots and the adaptation of their services to new environments are tasks that usually require several days of expert work. With this in view, we present a multi-agent system made up of intelligent cameras and autonomous robots, which is easy and fast to deploy in different environments. The cameras will enhance the robot perceptions and allow them to react to situations that require their services. Additionally, the cameras will support the movement of the robots. This will enable our robots to navigate even when there are not maps available. The deployment of our system does not require expertise and can be done in a short period of time, since neither software nor hardware tuning is needed. Every system task is automatic, distributed and based on self-organization processes. Our system is scalable, robust, and flexible to the environment. We carried out several real world experiments, which show the good performance of our proposal.

  8. Self-Organized Multi-Camera Network for a Fast and Easy Deployment of Ubiquitous Robots in Unknown Environments

    PubMed Central

    Canedo-Rodriguez, Adrián; Iglesias, Roberto; Regueiro, Carlos V.; Alvarez-Santos, Victor; Pardo, Xose Manuel

    2013-01-01

    To bring cutting edge robotics from research centres to social environments, the robotics community must start providing affordable solutions: the costs must be reduced and the quality and usefulness of the robot services must be enhanced. Unfortunately, nowadays the deployment of robots and the adaptation of their services to new environments are tasks that usually require several days of expert work. With this in view, we present a multi-agent system made up of intelligent cameras and autonomous robots, which is easy and fast to deploy in different environments. The cameras will enhance the robot perceptions and allow them to react to situations that require their services. Additionally, the cameras will support the movement of the robots. This will enable our robots to navigate even when there are not maps available. The deployment of our system does not require expertise and can be done in a short period of time, since neither software nor hardware tuning is needed. Every system task is automatic, distributed and based on self-organization processes. Our system is scalable, robust, and flexible to the environment. We carried out several real world experiments, which show the good performance of our proposal. PMID:23271604

  9. A priori Estimates for 3D Incompressible Current-Vortex Sheets

    NASA Astrophysics Data System (ADS)

    Coulombel, J.-F.; Morando, A.; Secchi, P.; Trebeschi, P.

    2012-04-01

    We consider the free boundary problem for current-vortex sheets in ideal incompressible magneto-hydrodynamics. It is known that current-vortex sheets may be at most weakly (neutrally) stable due to the existence of surface waves solutions to the linearized equations. The existence of such waves may yield a loss of derivatives in the energy estimate of the solution with respect to the source terms. However, under a suitable stability condition satisfied at each point of the initial discontinuity and a flatness condition on the initial front, we prove an a priori estimate in Sobolev spaces for smooth solutions with no loss of derivatives. The result of this paper gives some hope for proving the local existence of smooth current-vortex sheets without resorting to a Nash-Moser iteration. Such result would be a rigorous confirmation of the stabilizing effect of the magnetic field on Kelvin-Helmholtz instabilities, which is well known in astrophysics.

  10. Application of Bayesian a Priori Distributions for Vehicles' Video Tracking Systems

    NASA Astrophysics Data System (ADS)

    Mazurek, Przemysław; Okarma, Krzysztof

    Intelligent Transportation Systems (ITS) helps to improve the quality and quantity of many car traffic parameters. The use of the ITS is possible when the adequate measuring infrastructure is available. Video systems allow for its implementation with relatively low cost due to the possibility of simultaneous video recording of a few lanes of the road at a considerable distance from the camera. The process of tracking can be realized through different algorithms, the most attractive algorithms are Bayesian, because they use the a priori information derived from previous observations or known limitations. Use of this information is crucial for improving the quality of tracking especially for difficult observability conditions, which occur in the video systems under the influence of: smog, fog, rain, snow and poor lighting conditions.

  11. A Priori Bound on the Velocity in Axially Symmetric Navier-Stokes Equations

    NASA Astrophysics Data System (ADS)

    Lei, Zhen; Navas, Esteban A.; Zhang, Qi S.

    2016-01-01

    Let v be the velocity of Leray-Hopf solutions to the axially symmetric three-dimensional Navier-Stokes equations. Under suitable conditions for initial values, we prove the following a priori bound |v(x, t)| ≤ C |ln r|^{1/2}/r^2, qquad 0 < r ≤ 1/2, where r is the distance from x to the z axis, and C is a constant depending only on the initial value. This provides a pointwise upper bound (worst case scenario) for possible singularities, while the recent papers (Chiun-Chuan et al., Commun PDE 34(1-3):203-232, 2009; Koch et al., Acta Math 203(1):83-105, 2009) gave a lower bound. The gap is polynomial order 1 modulo a half log term.

  12. GNSS Precise Kinematic Positioning for Multiple Kinematic Stations Based on A Priori Distance Constraints.

    PubMed

    He, Kaifei; Xu, Tianhe; Förste, Christoph; Petrovic, Svetozar; Barthelmes, Franz; Jiang, Nan; Flechtner, Frank

    2016-04-01

    When applying the Global Navigation Satellite System (GNSS) for precise kinematic positioning in airborne and shipborne gravimetry, multiple GNSS receiving equipment is often fixed mounted on the kinematic platform carrying the gravimetry instrumentation. Thus, the distances among these GNSS antennas are known and invariant. This information can be used to improve the accuracy and reliability of the state estimates. For this purpose, the known distances between the antennas are applied as a priori constraints within the state parameters adjustment. These constraints are introduced in such a way that their accuracy is taken into account. To test this approach, GNSS data of a Baltic Sea shipborne gravimetric campaign have been used. The results of our study show that an application of distance constraints improves the accuracy of the GNSS kinematic positioning, for example, by about 4 mm for the radial component.

  13. GNSS Precise Kinematic Positioning for Multiple Kinematic Stations Based on A Priori Distance Constraints

    PubMed Central

    He, Kaifei; Xu, Tianhe; Förste, Christoph; Petrovic, Svetozar; Barthelmes, Franz; Jiang, Nan; Flechtner, Frank

    2016-01-01

    When applying the Global Navigation Satellite System (GNSS) for precise kinematic positioning in airborne and shipborne gravimetry, multiple GNSS receiving equipment is often fixed mounted on the kinematic platform carrying the gravimetry instrumentation. Thus, the distances among these GNSS antennas are known and invariant. This information can be used to improve the accuracy and reliability of the state estimates. For this purpose, the known distances between the antennas are applied as a priori constraints within the state parameters adjustment. These constraints are introduced in such a way that their accuracy is taken into account. To test this approach, GNSS data of a Baltic Sea shipborne gravimetric campaign have been used. The results of our study show that an application of distance constraints improves the accuracy of the GNSS kinematic positioning, for example, by about 4 mm for the radial component. PMID:27043580

  14. Valid approximation of spatially distributed grain size distributions - A priori information encoded to a feedforward network

    NASA Astrophysics Data System (ADS)

    Berthold, T.; Milbradt, P.; Berkhahn, V.

    2018-04-01

    This paper presents a model for the approximation of multiple, spatially distributed grain size distributions based on a feedforward neural network. Since a classical feedforward network does not guarantee to produce valid cumulative distribution functions, a priori information is incor porated into the model by applying weight and architecture constraints. The model is derived in two steps. First, a model is presented that is able to produce a valid distribution function for a single sediment sample. Although initially developed for sediment samples, the model is not limited in its application; it can also be used to approximate any other multimodal continuous distribution function. In the second part, the network is extended in order to capture the spatial variation of the sediment samples that have been obtained from 48 locations in the investigation area. Results show that the model provides an adequate approximation of grain size distributions, satisfying the requirements of a cumulative distribution function.

  15. A priori analysis: an application to the estimate of the uncertainty in course grades

    NASA Astrophysics Data System (ADS)

    Lippi, G. L.

    2014-07-01

    A priori analysis (APA) is discussed as a tool to assess the reliability of grades in standard curricular courses. This unusual, but striking, application is presented when teaching the section on the data treatment of a laboratory course to illustrate the characteristics of the APA and its potential for widespread use, beyond the traditional physics curriculum. The conditions necessary for this kind of analysis are discussed, the general framework is set out and a specific example is given to illustrate its various aspects. Students are often struck by this unusual application and are more apt to remember the APA. Instructors may also benefit from some of the gathered information, as discussed in the paper.

  16. Investigating industrial investigation: examining the impact of a priori knowledge and tunnel vision education.

    PubMed

    Maclean, Carla L; Brimacombe, C A Elizabeth; Lindsay, D Stephen

    2013-12-01

    The current study addressed tunnel vision in industrial incident investigation by experimentally testing how a priori information and a human bias (generated via the fundamental attribution error or correspondence bias) affected participants' investigative behavior as well as the effectiveness of a debiasing intervention. Undergraduates and professional investigators engaged in a simulated industrial investigation exercise. We found that participants' judgments were biased by knowledge about the safety history of either a worker or piece of equipment and that a human bias was evident in participants' decision making. However, bias was successfully reduced with "tunnel vision education." Professional investigators demonstrated a greater sophistication in their investigative decision making compared to undergraduates. The similarities and differences between these two populations are discussed. (c) 2013 APA, all rights reserved

  17. Predicting thermal history a-priori for magnetic nanoparticle hyperthermia of internal carcinoma

    NASA Astrophysics Data System (ADS)

    Dhar, Purbarun; Sirisha Maganti, Lakshmi

    2017-08-01

    This article proposes a simplistic and realistic method where a direct analytical expression can be derived for the temperature field within a tumour during magnetic nanoparticle hyperthermia. The approximated analytical expression for thermal history within the tumour is derived based on the lumped capacitance approach and considers all therapy protocols and parameters. The present method is simplistic and provides an easy framework for estimating hyperthermia protocol parameters promptly. The model has been validated with respect to several experimental reports on animal models such as mice/rabbit/hamster and human clinical trials. It has been observed that the model is able to accurately estimate the thermal history within the carcinoma during the hyperthermia therapy. The present approach may find implications in a-priori estimation of the thermal history in internal tumours for optimizing magnetic hyperthermia treatment protocols with respect to the ablation time, tumour size, magnetic drug concentration, field strength, field frequency, nanoparticle material and size, tumour location, and so on.

  18. Developing an A Priori Database for Passive Microwave Snow Water Retrievals Over Ocean

    NASA Astrophysics Data System (ADS)

    Yin, Mengtao; Liu, Guosheng

    2017-12-01

    A physically optimized a priori database is developed for Global Precipitation Measurement Microwave Imager (GMI) snow water retrievals over ocean. The initial snow water content profiles are derived from CloudSat Cloud Profiling Radar (CPR) measurements. A radiative transfer model in which the single-scattering properties of nonspherical snowflakes are based on the discrete dipole approximate results is employed to simulate brightness temperatures and their gradients. Snow water content profiles are then optimized through a one-dimensional variational (1D-Var) method. The standard deviations of the difference between observed and simulated brightness temperatures are in a similar magnitude to the observation errors defined for observation error covariance matrix after the 1D-Var optimization, indicating that this variational method is successful. This optimized database is applied in a Bayesian retrieval snow water algorithm. The retrieval results indicated that the 1D-Var approach has a positive impact on the GMI retrieved snow water content profiles by improving the physical consistency between snow water content profiles and observed brightness temperatures. Global distribution of snow water contents retrieved from the a priori database is compared with CloudSat CPR estimates. Results showed that the two estimates have a similar pattern of global distribution, and the difference of their global means is small. In addition, we investigate the impact of using physical parameters to subset the database on snow water retrievals. It is shown that using total precipitable water to subset the database with 1D-Var optimization is beneficial for snow water retrievals.

  19. Influence of a priori profiles on trend calculations from Umkehr data

    NASA Astrophysics Data System (ADS)

    Mateer, C. L.; Dütsch, H. U.; Staehelin, J.; Deluisi, J. J.

    1996-07-01

    Although the new (1992) ozone profile retrieval algorithm for Umkehr measurements provides much better agreement with ozone sounding results than the old (1964) algorithm, considerable discrepancies remain with respect to ozone trends at different levels in the atmosphere. These discrepancies have been found by the comparison of long-term trends obtained from the Umkehr measurements at Arosa and the ozone balloon soundings at Payerne (Switzerland). It is investigated here whether these obvious discrepancies can be removed by using time-dependent a priori profiles. This procedure is successful only in the lowest part of the atmosphere, below about 19 km. To further explore this problem, synthetic Umkehr observations are calculated from the ozonesonde profiles. Trends are calculated for both the synthetic and actual Umkehr observations. The difference pattern between these Umkehr observation trends is compared with the difference in ozone profile retrieval trends from the synthetic and actual observations. The distinctive difference patterns strongly indicate an inherent disagreement between the Umkehr observations and the ozonesonde profiles. The application of corrections for stratospheric aerosol effects to the Umkehr profiles reduces, but does not eliminate, a discrepancy above 32 km. It is concluded that the discrepancies are due to the constant mixing ratio assumption used in computing the residual ozone above balloon burst level and to the fair-weather bias of Umkehr observations (there are Umkehr observations at Arosa on fewer than 20% of the sonde observation days at Payerne). This sampling difference influences the results for the lower stratosphere. The study furthermore indicates that the ozone trends derived from Umkehr measurements for altitudes above about 32 km are robust for time-dependent changes in the a priori profiles at lower altitudes. Based on the results of this study, we conclude with revised recommendations as to which atmospheric layers

  20. Rapid multi-wavelength optical assessment of circulating blood volume without a priori data

    NASA Astrophysics Data System (ADS)

    Loginova, Ekaterina V.; Zhidkova, Tatyana V.; Proskurnin, Mikhail A.; Zharov, Vladimir P.

    2016-03-01

    The measurement of circulating blood volume (CBV) is crucial in various medical conditions including surgery, iatrogenic problems, rapid fluid administration, transfusion of red blood cells, or trauma with extensive blood loss including battlefield injuries and other emergencies. Currently, available commercial techniques are invasive and time-consuming for trauma situations. Recently, we have proposed high-speed multi-wavelength photoacoustic/photothermal (PA/PT) flow cytometry for in vivo CBV assessment with multiple dyes as PA contrast agents (labels). As the first step, we have characterized the capability of this technique to monitor the clearance of three dyes (indocyanine green, methylene blue, and trypan blue) in an animal model. However, there are strong demands on improvements in PA/PT flow cytometry. As additional verification of our proof-of-concept of this technique, we performed optical photometric CBV measurements in vitro. Three label dyes—methylene blue, crystal violet and, partially, brilliant green—were selected for simultaneous photometric determination of the components of their two-dye mixtures in the circulating blood in vitro without any extra data (like hemoglobin absorption) known a priori. The tests of single dyes and their mixtures in a flow system simulating a blood transfusion system showed a negligible difference between the sensitivities of the determination of these dyes under batch and flow conditions. For individual dyes, the limits of detection of 3×10-6 M‒3×10-6 M in blood were achieved, which provided their continuous determination at a level of 10-5 M for the CBV assessment without a priori data on the matrix. The CBV assessment with errors no higher than 4% were obtained, and the possibility to apply the developed procedure for optical photometric (flow cytometry) with laser sources was shown.

  1. Impact of high-resolution a priori profiles on satellite-based formaldehyde retrievals

    NASA Astrophysics Data System (ADS)

    Kim, Si-Wan; Natraj, Vijay; Lee, Seoyoung; Kwon, Hyeong-Ahn; Park, Rokjin; de Gouw, Joost; Frost, Gregory; Kim, Jhoon; Stutz, Jochen; Trainer, Michael; Tsai, Catalina; Warneke, Carsten

    2018-06-01

    Formaldehyde (HCHO) is either directly emitted from sources or produced during the oxidation of volatile organic compounds (VOCs) in the troposphere. It is possible to infer atmospheric HCHO concentrations using space-based observations, which may be useful for studying emissions and tropospheric chemistry at urban to global scales depending on the quality of the retrievals. In the near future, an unprecedented volume of satellite-based HCHO measurement data will be available from both geostationary and polar-orbiting platforms. Therefore, it is essential to develop retrieval methods appropriate for the next-generation satellites that measure at higher spatial and temporal resolution than the current ones. In this study, we examine the importance of fine spatial and temporal resolution a priori profile information on the retrieval by conducting approximately 45 000 radiative transfer (RT) model calculations in the Los Angeles Basin (LA Basin) megacity. Our analyses suggest that an air mass factor (AMF, a factor converting observed slant columns to vertical columns) based on fine spatial and temporal resolution a priori profiles can better capture the spatial distributions of the enhanced HCHO plumes in an urban area than the nearly constant AMFs used for current operational products by increasing the columns by ˜ 50 % in the domain average and up to 100 % at a finer scale. For this urban area, the AMF values are inversely proportional to the magnitude of the HCHO mixing ratios in the boundary layer. Using our optimized model HCHO results in the Los Angeles Basin that mimic the HCHO retrievals from future geostationary satellites, we illustrate the effectiveness of HCHO data from geostationary measurements for understanding and predicting tropospheric ozone and its precursors.

  2. A-Priori Rupture Models for Northern California Type-A Faults

    USGS Publications Warehouse

    Wills, Chris J.; Weldon, Ray J.; Field, Edward H.

    2008-01-01

    This appendix describes how a-priori rupture models were developed for the northern California Type-A faults. As described in the main body of this report, and in Appendix G, ?a-priori? models represent an initial estimate of the rate of single and multi-segment surface ruptures on each fault. Whether or not a given model is moment balanced (i.e., satisfies section slip-rate data) depends on assumptions made regarding the average slip on each segment in each rupture (which in turn depends on the chosen magnitude-area relationship). Therefore, for a given set of assumptions, or branch on the logic tree, the methodology of the present Working Group (WGCEP-2007) is to find a final model that is as close as possible to the a-priori model, in the least squares sense, but that also satisfies slip rate and perhaps other data. This is analogous the WGCEP- 2002 approach of effectively voting on the relative rate of each possible rupture, and then finding the closest moment-balance model (under a more limiting set of assumptions than adopted by the present WGCEP, as described in detail in Appendix G). The 2002 Working Group Report (WCCEP, 2003, referred to here as WGCEP-2002), created segmented earthquake rupture forecast models for all faults in the region, including some that had been designated as Type B faults in the NSHMP, 1996, and one that had not previously been considered. The 2002 National Seismic Hazard Maps used the values from WGCEP-2002 for all the faults in the region, essentially treating all the listed faults as Type A faults. As discussed in Appendix A, the current WGCEP found that there are a number of faults with little or no data on slip-per-event, or dates of previous earthquakes. As a result, the WGCEP recommends that faults with minimal available earthquake recurrence data: the Greenville, Mount Diablo, San Gregorio, Monte Vista-Shannon and Concord-Green Valley be modeled as Type B faults to be consistent with similarly poorly-known faults statewide

  3. A priori study of subgrid-scale features in turbulent Rayleigh-Bénard convection

    NASA Astrophysics Data System (ADS)

    Dabbagh, F.; Trias, F. X.; Gorobets, A.; Oliva, A.

    2017-10-01

    At the crossroad between flow topology analysis and turbulence modeling, a priori studies are a reliable tool to understand the underlying physics of the subgrid-scale (SGS) motions in turbulent flows. In this paper, properties of the SGS features in the framework of a large-eddy simulation are studied for a turbulent Rayleigh-Bénard convection (RBC). To do so, data from direct numerical simulation (DNS) of a turbulent air-filled RBC in a rectangular cavity of aspect ratio unity and π spanwise open-ended distance are used at two Rayleigh numbers R a ∈{1 08,1 010 } [Dabbagh et al., "On the evolution of flow topology in turbulent Rayleigh-Bénard convection," Phys. Fluids 28, 115105 (2016)]. First, DNS at Ra = 108 is used to assess the performance of eddy-viscosity models such as QR, Wall-Adapting Local Eddy-viscosity (WALE), and the recent S3PQR-models proposed by Trias et al. ["Building proper invariants for eddy-viscosity subgrid-scale models," Phys. Fluids 27, 065103 (2015)]. The outcomes imply that the eddy-viscosity modeling smoothes the coarse-grained viscous straining and retrieves fairly well the effect of the kinetic unfiltered scales in order to reproduce the coherent large scales. However, these models fail to approach the exact evolution of the SGS heat flux and are incapable to reproduce well the further dominant rotational enstrophy pertaining to the buoyant production. Afterwards, the key ingredients of eddy-viscosity, νt, and eddy-diffusivity, κt, are calculated a priori and revealed positive prevalent values to maintain a turbulent wind essentially driven by the mean buoyant force at the sidewalls. The topological analysis suggests that the effective turbulent diffusion paradigm and the hypothesis of a constant turbulent Prandtl number are only applicable in the large-scale strain-dominated areas in the bulk. It is shown that the bulk-dominated rotational structures of vortex-stretching (and its synchronous viscous dissipative structures) hold

  4. Allocating monitoring effort in the face of unknown unknowns

    USGS Publications Warehouse

    Wintle, B.A.; Runge, M.C.; Bekessy, S.A.

    2010-01-01

    There is a growing view that to make efficient use of resources, ecological monitoring should be hypothesis-driven and targeted to address specific management questions. 'Targeted' monitoring has been contrasted with other approaches in which a range of quantities are monitored in case they exhibit an alarming trend or provide ad hoc ecological insights. The second form of monitoring, described as surveillance, has been criticized because it does not usually aim to discern between competing hypotheses, and its benefits are harder to identify a priori. The alternative view is that the existence of surveillance data may enable rapid corroboration of emerging hypotheses or help to detect important 'unknown unknowns' that, if undetected, could lead to catastrophic outcomes or missed opportunities. We derive a model to evaluate and compare the efficiency of investments in surveillance and targeted monitoring. We find that a decision to invest in surveillance monitoring may be defensible if: (1) the surveillance design is more likely to discover or corroborate previously unknown phenomena than a targeted design and (2) the expected benefits (or avoided costs) arising from discovery are substantially higher than those arising from a well-planned targeted design. Our examination highlights the importance of being explicit about the objectives, costs and expected benefits of monitoring in a decision analytic framework. ?? 2010 Blackwell Publishing Ltd/CNRS.

  5. Class Identification Efficacy in Piecewise GMM with Unknown Turning Points

    ERIC Educational Resources Information Center

    Ning, Ling; Luo, Wen

    2018-01-01

    Piecewise GMM with unknown turning points is a new procedure to investigate heterogeneous subpopulations' growth trajectories consisting of distinct developmental phases. Unlike the conventional PGMM, which relies on theory or experiment design to specify turning points a priori, the new procedure allows for an optimal location of turning points…

  6. A Priori Analysis of Flamelet-Based Modeling for a Dual-Mode Scramjet Combustor

    NASA Technical Reports Server (NTRS)

    Quinlan, Jesse R.; McDaniel, James C.; Drozda, Tomasz G.; Lacaze, Guilhem; Oefelein, Joseph

    2014-01-01

    An a priori investigation of the applicability of flamelet-based combustion models to dual-mode scramjet combustion was performed utilizing Reynolds-averaged simulations (RAS). For this purpose, the HIFiRE Direct Connect Rig (HDCR) flowpath, fueled with a JP-7 fuel surrogate and operating in dual- and scram-mode was considered. The chemistry of the JP-7 fuel surrogate was modeled using a 22 species, 18-step chemical reaction mechanism. Simulation results were compared to experimentally-obtained, time-averaged, wall pressure measurements to validate the RAS solutions. The analysis of the dual-mode operation of this flowpath showed regions of predominately non-premixed, high-Damkohler number, combustion. Regions of premixed combustion were also present but associated with only a small fraction of the total heat-release in the flow. This is in contrast to the scram-mode operation, where a comparable amount of heat is released from non-premixed and premixed combustion modes. Representative flamelet boundary conditions were estimated by analyzing probability density functions for temperature and pressure for pure fuel and oxidizer conditions. The results of the present study reveal the potential for a flamelet model to accurately model the combustion processes in the HDCR and likely other high-speed flowpaths of engineering interest.

  7. Improving image reconstruction of bioluminescence imaging using a priori information from ultrasound imaging (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Jayet, Baptiste; Ahmad, Junaid; Taylor, Shelley L.; Hill, Philip J.; Dehghani, Hamid; Morgan, Stephen P.

    2017-03-01

    Bioluminescence imaging (BLI) is a commonly used imaging modality in biology to study cancer in vivo in small animals. Images are generated using a camera to map the optical fluence emerging from the studied animal, then a numerical reconstruction algorithm is used to locate the sources and estimate their sizes. However, due to the strong light scattering properties of biological tissues, the resolution is very limited (around a few millimetres). Therefore obtaining accurate information about the pathology is complicated. We propose a combined ultrasound/optics approach to improve accuracy of these techniques. In addition to the BLI data, an ultrasound probe driven by a scanner is used for two main objectives. First, to obtain a pure acoustic image, which provides structural information of the sample. And second, to alter the light emission by the bioluminescent sources embedded inside the sample, which is monitored using a high speed optical detector (e.g. photomultiplier tube). We will show that this last measurement, used in conjunction with the ultrasound data, can provide accurate localisation of the bioluminescent sources. This can be used as a priori information by the numerical reconstruction algorithm, greatly increasing the accuracy of the BLI image reconstruction as compared to the image generated using only BLI data.

  8. Improving diffuse optical tomography with structural a priori from fluorescence diffuse optical tomography

    NASA Astrophysics Data System (ADS)

    Ma, Wenjuan; Gao, Feng; Duan, Linjing; Zhu, Qingzhen; Wang, Xin; Zhang, Wei; Wu, Linhui; Yi, Xi; Zhao, Huijuan

    2012-03-01

    We obtain absorption and scattering reconstructed images by incorporating a priori information of target location obtained from fluorescence diffuse optical tomography (FDOT) into the diffuse optical tomography (DOT). The main disadvantage of DOT lies in the low spatial resolution resulting from highly scattering nature of tissue in the near-infrared (NIR), but one can use it to monitor hemoglobin concentration and oxygen saturation simultaneously, as well as several other cheomphores such as water, lipids, and cytochrome-c-oxidase. Up to date, extensive effort has been made to integrate DOT with other imaging modalities such as MRI, CT, to obtain accurate optical property maps of the tissue. However, the experimental apparatus is intricate. In this study, DOT image reconstruction algorithm that incorporates a prior structural information provided by FDOT is investigated in an attempt to optimize recovery of a simulated optical property distribution. By use of a specifically designed multi-channel time-correlated single photon counting system, the proposed scheme in a transmission mode is experimentally validated to achieve simultaneous reconstruction of the fluorescent yield, lifetime, absorption and scattering coefficient. The experimental results demonstrate that the quantitative recovery of the tumor optical properties has doubled and the spatial resolution improves as well by applying the new improved method.

  9. A priori and a posteriori analysis of the flow around a rectangular cylinder

    NASA Astrophysics Data System (ADS)

    Cimarelli, A.; Leonforte, A.; Franciolini, M.; De Angelis, E.; Angeli, D.; Crivellini, A.

    2017-11-01

    The definition of a correct mesh resolution and modelling approach for the Large Eddy Simulation (LES) of the flow around a rectangular cylinder is recognized to be a rather elusive problem as shown by the large scatter of LES results present in the literature. In the present work, we aim at assessing this issue by performing an a priori analysis of Direct Numerical Simulation (DNS) data of the flow. This approach allows us to measure the ability of the LES field on reproducing the main flow features as a function of the resolution employed. Based on these results, we define a mesh resolution which maximize the opposite needs of reducing the computational costs and of adequately resolving the flow dynamics. The effectiveness of the resolution method proposed is then verified by means of an a posteriori analysis of actual LES data obtained by means of the implicit LES approach given by the numerical properties of the Discontinuous Galerkin spatial discretization technique. The present work represents a first step towards a best practice for LES of separating and reattaching flows.

  10. SPARSE—A subgrid particle averaged Reynolds stress equivalent model: testing with a priori closure

    PubMed Central

    Davis, Sean L.; Sen, Oishik; Udaykumar, H. S.

    2017-01-01

    A Lagrangian particle cloud model is proposed that accounts for the effects of Reynolds-averaged particle and turbulent stresses and the averaged carrier-phase velocity of the subparticle cloud scale on the averaged motion and velocity of the cloud. The SPARSE (subgrid particle averaged Reynolds stress equivalent) model is based on a combination of a truncated Taylor expansion of a drag correction function and Reynolds averaging. It reduces the required number of computational parcels to trace a cloud of particles in Eulerian–Lagrangian methods for the simulation of particle-laden flow. Closure is performed in an a priori manner using a reference simulation where all particles in the cloud are traced individually with a point-particle model. Comparison of a first-order model and SPARSE with the reference simulation in one dimension shows that both the stress and the averaging of the carrier-phase velocity on the cloud subscale affect the averaged motion of the particle. A three-dimensional isotropic turbulence computation shows that only one computational parcel is sufficient to accurately trace a cloud of tens of thousands of particles. PMID:28413341

  11. SPARSE-A subgrid particle averaged Reynolds stress equivalent model: testing with a priori closure.

    PubMed

    Davis, Sean L; Jacobs, Gustaaf B; Sen, Oishik; Udaykumar, H S

    2017-03-01

    A Lagrangian particle cloud model is proposed that accounts for the effects of Reynolds-averaged particle and turbulent stresses and the averaged carrier-phase velocity of the subparticle cloud scale on the averaged motion and velocity of the cloud. The SPARSE (subgrid particle averaged Reynolds stress equivalent) model is based on a combination of a truncated Taylor expansion of a drag correction function and Reynolds averaging. It reduces the required number of computational parcels to trace a cloud of particles in Eulerian-Lagrangian methods for the simulation of particle-laden flow. Closure is performed in an a priori manner using a reference simulation where all particles in the cloud are traced individually with a point-particle model. Comparison of a first-order model and SPARSE with the reference simulation in one dimension shows that both the stress and the averaging of the carrier-phase velocity on the cloud subscale affect the averaged motion of the particle. A three-dimensional isotropic turbulence computation shows that only one computational parcel is sufficient to accurately trace a cloud of tens of thousands of particles.

  12. A Priori Analyses of Three Subgrid-Scale Models for One-Parameter Families of Filters

    NASA Technical Reports Server (NTRS)

    Pruett, C. David; Adams, Nikolaus A.

    1998-01-01

    The decay of isotropic turbulence a compressible flow is examined by direct numerical simulation (DNS). A priori analyses of the DNS data are then performed to evaluate three subgrid-scale (SGS) models for large-eddy simulation (LES): a generalized Smagorinsky model (M1), a stress-similarity model (M2), and a gradient model (M3). The models exploit one-parameter second- or fourth-order filters of Pade type, which permit the cutoff wavenumber k(sub c) to be tuned independently of the grid increment (delta)x. The modeled (M) and exact (E) SGS-stresses are compared component-wise by correlation coefficients of the form C(E,M) computed over the entire three-dimensional fields. In general, M1 correlates poorly against exact stresses (C < 0.2), M3 correlates moderately well (C approx. 0.6), and M2 correlates remarkably well (0.8 < C < 1.0). Specifically, correlations C(E, M2) are high provided the grid and test filters are of the same order. Moreover, the highest correlations (C approx.= 1.0) result whenever the grid and test filters are identical (in both order and cutoff). Finally, present results reveal the exact SGS stresses obtained by grid filters of differing orders to be only moderately well correlated. Thus, in LES the model should not be specified independently of the filter.

  13. The importance of using dynamical a-priori profiles for infrared O3 retrievals : the case of IASI.

    NASA Astrophysics Data System (ADS)

    Peiro, H.; Emili, E.; Le Flochmoen, E.; Barret, B.; Cariolle, D.

    2016-12-01

    Tropospheric ozone (O3) is a trace gas involved in the global greenhouse effect. To quantify its contribution to global warming, an accurate determination of O3 profiles is necessary. The instrument IASI (Infrared Atmospheric Sounding Interferometer), on board satellite MetOP-A, is the more sensitive sensor to tropospheric O3 with a high spatio-temporal coverage. Satellite retrievals are often based on the inversion of the measured radiance data with a variational approach. This requires an a priori profile and the correspondent error covariance matrix (COV) as ancillary input. Previous studies have shown some biases ( 20%) in IASI retrievals for tropospheric column in the Southern Hemisphere (SH). A possible source of errors is caused by the a priori profile. This study aims to i) build a dynamical a priori profile O3 with a Chemistry Transport Model (CTM), ii) integrate and to demonstrate the interest of this a priori profile in IASI retrievals.Global O3 profiles are retrieved from IASI radiances with the SOFRID (Software for a fast Retrieval of IASI Data) algorithm. It is based on the RTTOV (Radiative Transfer for TOVS) code and a 1D-Var retrieval scheme. Until now, a constant a priori profile was based on a combination of MOZAIC, WOUDC-SHADOZ and Aura/MLS data named here CLIM PR. The global CTM MOCAGE (Modèle de Chimie Atmosphérique à Grande Echelle) has been used with a linear O3 chemistry scheme to assimilate Microwave Limb Sounder (MLS) data. The model resolution of 2°x2°, with 60 sigma-hybrid vertical levels covering the stratosphere has been used. MLS level 2 products have been assimilated with a 4D-VAR variational algorithm to constrain stratospheric O3 and obtain high quality a priori profiles O3 above the tropopause. From this reanalysis, we built these profiles at a 6h frequency on a coarser resolution grid 10°x20° named MOCAGE+MLS PR.Statistical comparisons between retrievals and ozonesondes have shown better correlations and smaller biases for

  14. Considerations about expected a posteriori estimation in adaptive testing: adaptive a priori, adaptive correction for bias, and adaptive integration interval.

    PubMed

    Raiche, Gilles; Blais, Jean-Guy

    2009-01-01

    In a computerized adaptive test, we would like to obtain an acceptable precision of the proficiency level estimate using an optimal number of items. Unfortunately, decreasing the number of items is accompanied by a certain degree of bias when the true proficiency level differs significantly from the a priori estimate. The authors suggest that it is possible to reduced the bias, and even the standard error of the estimate, by applying to each provisional estimation one or a combination of the following strategies: adaptive correction for bias proposed by Bock and Mislevy (1982), adaptive a priori estimate, and adaptive integration interval.

  15. A priori motion models for four-dimensional reconstruction in gated cardiac SPECT

    SciTech Connect

    Lalush, D.S.; Tsui, B.M.W.; Cui, Lin

    1996-12-31

    We investigate the benefit of incorporating a priori assumptions about cardiac motion in a fully four-dimensional (4D) reconstruction algorithm for gated cardiac SPECT. Previous work has shown that non-motion-specific 4D Gibbs priors enforcing smoothing in time and space can control noise while preserving resolution. In this paper, we evaluate methods for incorporating known heart motion in the Gibbs prior model. The new model is derived by assigning motion vectors to each 4D voxel, defining the movement of that volume of activity into the neighboring time frames. Weights for the Gibbs cliques are computed based on these {open_quotes}most likely{close_quotes} motion vectors.more » To evaluate, we employ the mathematical cardiac-torso (MCAT) phantom with a new dynamic heart model that simulates the beating and twisting motion of the heart. Sixteen realistically-simulated gated datasets were generated, with noise simulated to emulate a real Tl-201 gated SPECT study. Reconstructions were performed using several different reconstruction algorithms, all modeling nonuniform attenuation and three-dimensional detector response. These include ML-EM with 4D filtering, 4D MAP-EM without prior motion assumption, and 4D MAP-EM with prior motion assumptions. The prior motion assumptions included both the correct motion model and incorrect models. Results show that reconstructions using the 4D prior model can smooth noise and preserve time-domain resolution more effectively than 4D linear filters. We conclude that modeling of motion in 4D reconstruction algorithms can be a powerful tool for smoothing noise and preserving temporal resolution in gated cardiac studies.« less

  16. Lost in space: Onboard star identification using CCD star tracker data without an a priori attitude

    NASA Technical Reports Server (NTRS)

    Ketchum, Eleanor A.; Tolson, Robert H.

    1993-01-01

    There are many algorithms in use today which determine spacecraft attitude by identifying stars in the field of view of a star tracker. Some methods, which date from the early 1960's, compare the angular separation between observed stars with a small catalog. In the last 10 years, several methods have been developed which speed up the process and reduce the amount of memory needed, a key element to onboard attitude determination. However, each of these methods require some a priori knowledge of the spacecraft attitude. Although the Sun and magnetic field generally provide the necessary coarse attitude information, there are occasions when a spacecraft could get lost when it is not prudent to wait for sunlight. Also, the possibility of efficient attitude determination using only the highly accurate CCD star tracker could lead to fully autonomous spacecraft attitude determination. The need for redundant coarse sensors could thus be eliminated at substantial cost reduction. Some groups have extended their algorithms to implement a computation intense full sky scan. Some require large data bases. Both storage and speed are concerns for autonomous onboard systems. Neural network technology is even being explored by some as a possible solution, but because of the limited number of patterns that can be stored and large overhead, nothing concrete has resulted from these efforts. This paper presents an algorithm which, by descretizing the sky and filtering by visual magnitude of the brightness observed star, speeds up the lost in space star identification process while reducing the amount of necessary onboard computer storage compared to existing techniques.

  17. Quantifying the sensitivity of aerosol optical depths retrieved from MSG SEVIRI to a priori data

    NASA Astrophysics Data System (ADS)

    Bulgin, C. E.; Palmer, P. I.; Merchant, C. J.; Siddans, R.; Poulsen, C.; Grainger, R. G.; Thomas, G.; Carboni, E.; McConnell, C.; Highwood, E.

    2009-12-01

    Radiative forcing contributions from aerosol direct and indirect effects remain one of the most uncertain components of the climate system. Satellite observations of aerosol optical properties offer important constraints on atmospheric aerosols but their sensitivity to prior assumptions must be better characterized before they are used effectively to reduce uncertainty in aerosol radiative forcing. We assess the sensitivity of the Oxford-RAL Aerosol and Cloud (ORAC) optimal estimation retrieval of aerosol optical depth (AOD) from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) to a priori aerosol data. SEVIRI is a geostationary satellite instrument centred over Africa and the neighbouring Atlantic Ocean, routinely sampling desert dust and biomass burning outflow from Africa. We quantify the uncertainty in SEVIRI AOD retrievals in the presence of desert dust by comparing retrievals that use prior information from the Optical Properties of Aerosol and Cloud (OPAC) database, with those that use measured aerosol properties during the Dust Outflow and Deposition to the Ocean (DODO) aircraft campaign (August, 2006). We also assess the sensitivity of retrieved AODs to changes in solar zenith angle, and the vertical profile of aerosol effective radius and extinction coefficient input into the retrieval forward model. Currently the ORAC retrieval scheme retrieves AODs for five aerosol types (desert dust, biomass burning, maritime, urban and continental) and chooses the most appropriate AOD based on the cost functions. We generate an improved prior aerosol speciation database for SEVIRI based on a statistical analysis of a Saharan Dust Index (SDI) determined using variances of different brightness temperatures, and organic and black carbon tracers from the GEOS-Chem chemistry transport model. This database is described as a function of season and time of day. We quantify the difference in AODs between those chosen based on prior information from the SDI and GEOS

  18. Limited angle breast ultrasound tomography with a priori information and artifact removal

    NASA Astrophysics Data System (ADS)

    Jintamethasawat, Rungroj; Zhu, Yunhao; Kripfgans, Oliver D.; Yuan, Jie; Goodsitt, Mitchell M.; Carson, Paul L.

    2017-03-01

    In B-mode images from dual-sided ultrasound, it has been shown that by delineating structures suspected of being relatively homogeneous, one can enhance limited angle tomography to produce speed of sound images in the same view as X-ray Digital Breast Tomography (DBT). This could allow better breast cancer detection and discrimination, as well as improved registration of the ultrasound and X-ray images, because of the similarity of SOS and X-ray contrast in the breast. However, this speed of sound reconstruction method relies strongly on B-mode or other reflection mode segmentation. If that information is limited or incorrect, artifacts will appear in the reconstructed images. Therefore, the iterative speed of sound reconstruction algorithm has been modified in a manner of simultaneously utilizing the image segmentations and removing most artifacts. The first step of incorporating a priori information is solved by any nonlinearnonconvex optimization method while artifact removal is accomplished by employing the fast split Bregman method to perform total-variation (TV) regularization for image denoising. The proposed method was demonstrated in simplified simulations of our dual-sided ultrasound scanner. To speed these computations two opposed 40-element ultrasound linear arrays with 0.5 MHz center frequency were simulated for imaging objects in a uniform background. The proposed speed of sound reconstruction method worked well with both bent-ray and full-wave inversion methods. This is also the first demonstration of successful full-wave medical ultrasound tomography in the limited angle geometry. Presented results lend credibility to a possible translation of this method to clinical breast imaging.

  19. An a priori DNS study of the shadow-position mixing model

    DOE PAGES

    Zhao, Xin -Yu; Bhagatwala, Ankit; Chen, Jacqueline H.; ...

    2016-01-15

    In this study, the modeling of mixing by molecular diffusion is a central aspect for transported probability density function (tPDF) methods. In this paper, the newly-proposed shadow position mixing model (SPMM) is examined, using a DNS database for a temporally evolving di-methyl ether slot jet flame. Two methods that invoke different levels of approximation are proposed to extract the shadow displacement (equivalent to shadow position) from the DNS database. An approach for a priori analysis of the mixing-model performance is developed. The shadow displacement is highly correlated with both mixture fraction and velocity, and the peak correlation coefficient of themore » shadow displacement and mixture fraction is higher than that of the shadow displacement and velocity. This suggests that the composition-space localness is reasonably well enforced by the model, with appropriate choices of model constants. The conditional diffusion of mixture fraction and major species from DNS and from SPMM are then compared, using mixing rates that are derived by matching the mixture fraction scalar dissipation rates. Good qualitative agreement is found, for the prediction of the locations of zero and maximum/minimum conditional diffusion locations for mixture fraction and individual species. Similar comparisons are performed for DNS and the IECM (interaction by exchange with the conditional mean) model. The agreement between SPMM and DNS is better than that between IECM and DNS, in terms of conditional diffusion iso-contour similarities and global normalized residual levels. It is found that a suitable value for the model constant c that controls the mixing frequency can be derived using the local normalized scalar variance, and that the model constant a controls the localness of the model. A higher-Reynolds-number test case is anticipated to be more appropriate to evaluate the mixing models, and stand-alone transported PDF simulations are required to more fully enforce

  20. Musical Probabilities, Abductive Reasoning, and Brain Mechanisms: Extended Perspective of "A Priori" Listening to Music within the Creative Cognition Approach

    ERIC Educational Resources Information Center

    Schmidt, Sebastian; Troge, Thomas A.; Lorrain, Denis

    2013-01-01

    A theory of listening to music is proposed. It suggests that, for listeners, the process of prediction is the starting point to experiencing music. This implies that perception of music starts through both a predisposed and an experience-based extrapolation into the future (this is labeled "a priori" listening). Indications for this…

  1. On the Implications of A Priori Constraints in Transdimensional Bayesian Inversion for Continental Lithospheric Layering

    NASA Astrophysics Data System (ADS)

    Roy, C.; Romanowicz, B. A.

    2017-12-01

    Monte Carlo methods are powerful approaches to solve nonlinear problems and are becoming very popular in Earth sciences. One reason being that, at first glance, no constraints or explicit regularization of model parameters are required. At second glance, one might realize that regularization is done through a prior. The choice of this prior, however, is subjective, and with its choice, unintended or undesired extra information can be injected into the problem. The principal criticism of Bayesian methods is that the prior can be "tuned" in order to get the expected solution. Consequently, detractors of the Bayesian method could easily argue that the solution is influenced by the form of the prior distribution, which choice is subjective. Hence, models obtained with Monte Carlo methods are still highly debated. Here we investigate the influence of a priori constraints (i.e., fixed crustal discontinuities) on the posterior probability distributions of estimated parameters, that is, vertical polarized shear velocity VSV and radial anisotropy ξ, in a transdimensional Bayesian inversion for continental lithospheric structure. We follow upon the work of Calò et al. (2016), who jointly inverted converted phases (P to S) without deconvolution and surface wave dispersion data, to obtain 1-D radial anisotropic shear wave velocity profiles in the North American craton. We aim at verifying whether the strong lithospheric layering found in the stable part of the craton is robust with respect to artifacts that might be caused by the methodology used. We test the hypothesis that the observed midlithospheric discontinuities result from (1) fixed crustal discontinuities in the reference model and (2) a fixed Vp/Vs ratio. The synthetic tests on two Earth models show that a fixed Vp/Vs ratio does not introduce artificial layering, even if the assumed value is slightly wrong. This is an important finding for real data inversion where the true value is not always available or accurate

  2. The origin of anomalous transport in porous media - is it possible to make a priori predictions?

    NASA Astrophysics Data System (ADS)

    Bijeljic, Branko; Blunt, Martin

    2013-04-01

    at approximately the average flow speed; in the carbonate with the widest velocity distribution the stagnant concentration peak is persistent, while the emergence of a smaller secondary mobile peak is observed, leading to a highly anomalous behavior. This defines different generic nature of non-Fickian transport in the three media and quantifies the effect of pore structure on transport. Moreover, the propagators obtained by the model are in a very good agreement with the propagators measured on beadpack, Bentheimer sandstone and Portland carbonate cores in nuclear magnetic resonance experiments. These findings demonstrate that it is possible to make a priori predictions of anomalous transport in porous media. The importance of these findings for transport in complex carbonate rock micro-CT images is discussed, classifying them in terms of degree of anomalous transport that can have an impact at the field scale. Extensions to reactive transport will be discussed.

  3. Learning Unknown Event Models

    DTIC Science & Technology

    2014-07-01

    Intelligence (www.aaai.org). All rights reserved. knowledge engineering, but it is often impractical due to high environment variance, or unknown events...distribution unlimited 13. SUPPLEMENTARY NOTES In Proceedings of the Twenty-Eighth AAAI Conference on Artificial Intelligence , 27-31 July 2014...autonomy for responding to unexpected events in strategy simulations. Computational Intelligence , 29(2), 187-206. Leake, D. B. (1991), Goal-based

  4. Modelling of subgrid-scale phenomena in supercritical transitional mixing layers: an a priori study

    NASA Astrophysics Data System (ADS)

    Selle, Laurent C.; Okong'o, Nora A.; Bellan, Josette; Harstad, Kenneth G.

    computationally intensive in LES. Several SGS flux models are tested on an a priori basis. The Smagorinsky (SM) model has a poor correlation with the data, while the gradient (GR) and scale-similarity (SS) models have high correlations. Calibrated model coefficients for the GR and SS models yield good agreement with the SGS fluxes, although statistically, the coefficients are not valid over all realizations. The GR model is also tested for the variances entering the calculation of the new terms in the momentum and energy equations; high correlations are obtained, although the calibrated coefficients are not statistically significant over the entire database at fixed filter size. As a manifestation of the small-scale supercritical mixing peculiarities, both scalar-dissipation visualizations and the scalar-dissipation probability density functions (PDF) are examined. The PDF is shown to exhibit minor peaks, with particular significance for those at larger scalar dissipation values than the mean, thus significantly departing from the Gaussian behaviour.

  5. Orbit determination of the Next-Generation Beidou satellites with Intersatellite link measurements and a priori orbit constraints

    NASA Astrophysics Data System (ADS)

    Ren, Xia; Yang, Yuanxi; Zhu, Jun; Xu, Tianhe

    2017-11-01

    Intersatellite Link (ISL) technology helps to realize the auto update of broadcast ephemeris and clock error parameters for Global Navigation Satellite System (GNSS). ISL constitutes an important approach with which to both improve the observation geometry and extend the tracking coverage of China's Beidou Navigation Satellite System (BDS). However, ISL-only orbit determination might lead to the constellation drift, rotation, and even lead to the divergence in orbit determination. Fortunately, predicted orbits with good precision can be used as a priori information with which to constrain the estimated satellite orbit parameters. Therefore, the precision of satellite autonomous orbit determination can be improved by consideration of a priori orbit information, and vice versa. However, the errors of rotation and translation in a priori orbit will remain in the ultimate result. This paper proposes a constrained precise orbit determination (POD) method for a sub-constellation of the new Beidou satellite constellation with only a few ISLs. The observation model of dual one-way measurements eliminating satellite clock errors is presented, and the orbit determination precision is analyzed with different data processing backgrounds. The conclusions are as follows. (1) With ISLs, the estimated parameters are strongly correlated, especially the positions and velocities of satellites. (2) The performance of determined BDS orbits will be improved by the constraints with more precise priori orbits. The POD precision is better than 45 m with a priori orbit constrain of 100 m precision (e.g., predicted orbits by telemetry tracking and control system), and is better than 6 m with precise priori orbit constraints of 10 m precision (e.g., predicted orbits by international GNSS monitoring & Assessment System (iGMAS)). (3) The POD precision is improved by additional ISLs. Constrained by a priori iGMAS orbits, the POD precision with two, three, and four ISLs is better than 6, 3, and 2

  6. The microbiology "unknown" misadventure.

    PubMed

    Boyer, B; DeBenedictis, K J; Master, R; Jones, R S

    1998-06-01

    A 19-year-old nursing student was hospitalized after several days of nausea, vomiting, diarrhea, and fevers. Salmonella paratyphi A was isolated from multiple blood cultures. Because this is an unlikely isolate in the United States, an investigation ensued. Two and a half weeks earlier, the student had been working on a microbiology laboratory exercise "unknown." Both the "unknown" organism and the patient's blood culture isolates were identified as S. paratyphi A, with the same biochemical reactions and antimicrobial susceptibility results. The patient's condition improved with antibiotic therapy, and she was discharged after 9 days in the hospital. Conclusions related to our investigation are as follows: (1) relatively virulent organisms were unnecessary to fulfill the laboratory objectives, (2) pipetting by mouth must never be allowed, (3) proper labeling of specimens is imperative, (4) instructors should have knowledge of laboratory safety regulations, and (5) it is the obligation of laboratory directors and administrators to provide a safe academic environment.

  7. Tomographic inversion of time-domain resistivity and chargeability data for the investigation of landfills using a priori information.

    PubMed

    De Donno, Giorgio; Cardarelli, Ettore

    2017-01-01

    In this paper, we present a new code for the modelling and inversion of resistivity and chargeability data using a priori information to improve the accuracy of the reconstructed model for landfill. When a priori information is available in the study area, we can insert them by means of inequality constraints on the whole model or on a single layer or assigning weighting factors for enhancing anomalies elongated in the horizontal or vertical directions. However, when we have to face a multilayered scenario with numerous resistive to conductive transitions (the case of controlled landfills), the effective thickness of the layers can be biased. The presented code includes a model-tuning scheme, which is applied after the inversion of field data, where the inversion of the synthetic data is performed based on an initial guess, and the absolute difference between the field and synthetic inverted models is minimized. The reliability of the proposed approach has been supported in two real-world examples; we were able to identify an unauthorized landfill and to reconstruct the geometrical and physical layout of an old waste dump. The combined analysis of the resistivity and chargeability (normalised) models help us to remove ambiguity due to the presence of the waste mass. Nevertheless, the presence of certain layers can remain hidden without using a priori information, as demonstrated by a comparison of the constrained inversion with a standard inversion. The robustness of the above-cited method (using a priori information in combination with model tuning) has been validated with the cross-section from the construction plans, where the reconstructed model is in agreement with the original design. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. A priori error estimates for an hp-version of the discontinuous Galerkin method for hyperbolic conservation laws

    NASA Technical Reports Server (NTRS)

    Bey, Kim S.; Oden, J. Tinsley

    1993-01-01

    A priori error estimates are derived for hp-versions of the finite element method for discontinuous Galerkin approximations of a model class of linear, scalar, first-order hyperbolic conservation laws. These estimates are derived in a mesh dependent norm in which the coefficients depend upon both the local mesh size h(sub K) and a number p(sub k) which can be identified with the spectral order of the local approximations over each element.

  9. LandScape: a simple method to aggregate p-values and other stochastic variables without a priori grouping.

    PubMed

    Wiuf, Carsten; Schaumburg-Müller Pallesen, Jonatan; Foldager, Leslie; Grove, Jakob

    2016-08-01

    In many areas of science it is custom to perform many, potentially millions, of tests simultaneously. To gain statistical power it is common to group tests based on a priori criteria such as predefined regions or by sliding windows. However, it is not straightforward to choose grouping criteria and the results might depend on the chosen criteria. Methods that summarize, or aggregate, test statistics or p-values, without relying on a priori criteria, are therefore desirable. We present a simple method to aggregate a sequence of stochastic variables, such as test statistics or p-values, into fewer variables without assuming a priori defined groups. We provide different ways to evaluate the significance of the aggregated variables based on theoretical considerations and resampling techniques, and show that under certain assumptions the FWER is controlled in the strong sense. Validity of the method was demonstrated using simulations and real data analyses. Our method may be a useful supplement to standard procedures relying on evaluation of test statistics individually. Moreover, by being agnostic and not relying on predefined selected regions, it might be a practical alternative to conventionally used methods of aggregation of p-values over regions. The method is implemented in Python and freely available online (through GitHub, see the Supplementary information).

  10. Evaluating a Priori Ozone Profile Information Used in TEMPO (Tropospheric Emissions: Monitoring of Pollution) Tropospheric Ozone Retrievals

    NASA Technical Reports Server (NTRS)

    Johnson, Matthew Stephen

    2017-01-01

    A primary objective for TOLNet is the evaluation and validation of space-based tropospheric O3 retrievals from future systems such as the Tropospheric Emissions: Monitoring of Pollution (TEMPO) satellite. This study is designed to evaluate the tropopause-based O3 climatology (TB-Clim) dataset which will be used as the a priori profile information in TEMPO O3 retrievals. This study also evaluates model simulated O3 profiles, which could potentially serve as a priori O3 profile information in TEMPO retrievals, from near-real-time (NRT) data assimilation model products (NASA Global Modeling and Assimilation Office (GMAO) Goddard Earth Observing System (GEOS-5) Forward Processing (FP) and Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA2)) and full chemical transport model (CTM), GEOS-Chem, simulations. The TB-Clim dataset and model products are evaluated with surface (0-2 km) and tropospheric (0-10 km) TOLNet observations to demonstrate the accuracy of the suggested a priori dataset and information which could potentially be used in TEMPO O3 algorithms. This study also presents the impact of individual a priori profile sources on the accuracy of theoretical TEMPO O3 retrievals in the troposphere and at the surface. Preliminary results indicate that while the TB-Clim climatological dataset can replicate seasonally-averaged tropospheric O3 profiles observed by TOLNet, model-simulated profiles from a full CTM (GEOS-Chem is used as a proxy for CTM O3 predictions) resulted in more accurate tropospheric and surface-level O3 retrievals from TEMPO when compared to hourly (diurnal cycle evaluation) and daily-averaged (daily variability evaluation) TOLNet observations. Furthermore, it was determined that when large daily-averaged surface O3 mixing ratios are observed (65 ppb), which are important for air quality purposes, TEMPO retrieval values at the surface display higher correlations and less bias when applying CTM a priori profile information

  11. Testing the hypothesis of neurodegeneracy in respiratory network function with a priori transected arterially perfused brain stem preparation of rat

    PubMed Central

    Jones, Sarah E.

    2016-01-01

    Degeneracy of respiratory network function would imply that anatomically discrete aspects of the brain stem are capable of producing respiratory rhythm. To test this theory we a priori transected brain stem preparations before reperfusion and reoxygenation at 4 rostrocaudal levels: 1.5 mm caudal to obex (n = 5), at obex (n = 5), and 1.5 (n = 7) and 3 mm (n = 6) rostral to obex. The respiratory activity of these preparations was assessed via recordings of phrenic and vagal nerves and lumbar spinal expiratory motor output. Preparations with a priori transection at level of the caudal brain stem did not produce stable rhythmic respiratory bursting, even when the arterial chemoreceptors were stimulated with sodium cyanide (NaCN). Reperfusion of brain stems that preserved the pre-Bötzinger complex (pre-BötC) showed spontaneous and sustained rhythmic respiratory bursting at low phrenic nerve activity (PNA) amplitude that occurred simultaneously in all respiratory motor outputs. We refer to this rhythm as the pre-BötC burstlet-type rhythm. Conserving circuitry up to the pontomedullary junction consistently produced robust high-amplitude PNA at lower burst rates, whereas sequential motor patterning across the respiratory motor outputs remained absent. Some of the rostrally transected preparations expressed both burstlet-type and regular PNA amplitude rhythms. Further analysis showed that the burstlet-type rhythm and high-amplitude PNA had 1:2 quantal relation, with burstlets appearing to trigger high-amplitude bursts. We conclude that no degenerate rhythmogenic circuits are located in the caudal medulla oblongata and confirm the pre-BötC as the primary rhythmogenic kernel. The absence of sequential motor patterning in a priori transected preparations suggests that pontine circuits govern respiratory pattern formation. PMID:26888109

  12. Testing the hypothesis of neurodegeneracy in respiratory network function with a priori transected arterially perfused brain stem preparation of rat.

    PubMed

    Jones, Sarah E; Dutschmann, Mathias

    2016-05-01

    Degeneracy of respiratory network function would imply that anatomically discrete aspects of the brain stem are capable of producing respiratory rhythm. To test this theory we a priori transected brain stem preparations before reperfusion and reoxygenation at 4 rostrocaudal levels: 1.5 mm caudal to obex (n = 5), at obex (n = 5), and 1.5 (n = 7) and 3 mm (n = 6) rostral to obex. The respiratory activity of these preparations was assessed via recordings of phrenic and vagal nerves and lumbar spinal expiratory motor output. Preparations with a priori transection at level of the caudal brain stem did not produce stable rhythmic respiratory bursting, even when the arterial chemoreceptors were stimulated with sodium cyanide (NaCN). Reperfusion of brain stems that preserved the pre-Bötzinger complex (pre-BötC) showed spontaneous and sustained rhythmic respiratory bursting at low phrenic nerve activity (PNA) amplitude that occurred simultaneously in all respiratory motor outputs. We refer to this rhythm as the pre-BötC burstlet-type rhythm. Conserving circuitry up to the pontomedullary junction consistently produced robust high-amplitude PNA at lower burst rates, whereas sequential motor patterning across the respiratory motor outputs remained absent. Some of the rostrally transected preparations expressed both burstlet-type and regular PNA amplitude rhythms. Further analysis showed that the burstlet-type rhythm and high-amplitude PNA had 1:2 quantal relation, with burstlets appearing to trigger high-amplitude bursts. We conclude that no degenerate rhythmogenic circuits are located in the caudal medulla oblongata and confirm the pre-BötC as the primary rhythmogenic kernel. The absence of sequential motor patterning in a priori transected preparations suggests that pontine circuits govern respiratory pattern formation. Copyright © 2016 the American Physiological Society.

  13. Parameter transferability within homogeneous regions and comparisons with predictions from a priori parameters in the eastern United States

    NASA Astrophysics Data System (ADS)

    Chouaib, Wafa; Alila, Younes; Caldwell, Peter V.

    2018-05-01

    The need for predictions of flow time-series persists at ungauged catchments, motivating the research goals of our study. By means of the Sacramento model, this paper explores the use of parameter transfer within homogeneous regions of similar climate and flow characteristics and makes comparisons with predictions from a priori parameters. We assessed the performance using the Nash-Sutcliffe (NS), bias, mean monthly hydrograph and flow duration curve (FDC). The study was conducted on a large dataset of 73 catchments within the eastern US. Two approaches to the parameter transferability were developed and evaluated; (i) the within homogeneous region parameter transfer using one donor catchment specific to each region, (ii) the parameter transfer disregarding the geographical limits of homogeneous regions, where one donor catchment was common to all regions. Comparisons between both parameter transfers enabled to assess the gain in performance from the parameter regionalization and its respective constraints and limitations. The parameter transfer within homogeneous regions outperformed the a priori parameters and led to a decrease in bias and increase in efficiency reaching a median NS of 0.77 and a NS of 0.85 at individual catchments. The use of FDC revealed the effect of bias on the inaccuracy of prediction from parameter transfer. In one specific region, of mountainous and forested catchments, the prediction accuracy of the parameter transfer was less satisfactory and equivalent to a priori parameters. In this region, the parameter transfer from the outsider catchment provided the best performance; less-biased with smaller uncertainty in medium flow percentiles (40%-60%). The large disparity of energy conditions explained the lack of performance from parameter transfer in this region. Besides, the subsurface stormflow is predominant and there is a likelihood of lateral preferential flow, which according to its specific properties further explained the reduced

  14. Use of a priori spectral information in the measurement of x-ray flux with filtered diode arrays

    DOE PAGES

    Marrs, R. E.; Widmann, K.; Brown, G. V.; ...

    2015-10-29

    Filtered x-ray diode (XRD) arrays are often used to measure x-ray spectra vs. time from spectrally continuous x-ray sources such as hohlraums. A priori models of the incident x-ray spectrum enable a more accurate unfolding of the x-ray flux as compared to the standard technique of modifying a thermal Planckian with spectral peaks or dips at the response energy of each filtered XRD channel. A model x-ray spectrum consisting of a thermal Planckian, a Gaussian at higher energy, and (in some cases) a high energy background provides an excellent fit to XRD-array measurements of x-ray emission from laser heated hohlraums.more » If high-resolution measurements of part of the x-ray emission spectrum are available, that information can be included in the a priori model. In cases where the x-ray emission spectrum is not Planckian, candidate x-ray spectra can be allowed or excluded by fitting them to measured XRD voltages. Here, examples are presented from the filtered XRD arrays, named Dante, at the National Ignition Facility and the Laboratory for Laser Energetics.« less

  15. A priori evaluation of two-stage cluster sampling for accuracy assessment of large-area land-cover maps

    USGS Publications Warehouse

    Wickham, J.D.; Stehman, S.V.; Smith, J.H.; Wade, T.G.; Yang, L.

    2004-01-01

    Two-stage cluster sampling reduces the cost of collecting accuracy assessment reference data by constraining sample elements to fall within a limited number of geographic domains (clusters). However, because classification error is typically positively spatially correlated, within-cluster correlation may reduce the precision of the accuracy estimates. The detailed population information to quantify a priori the effect of within-cluster correlation on precision is typically unavailable. Consequently, a convenient, practical approach to evaluate the likely performance of a two-stage cluster sample is needed. We describe such an a priori evaluation protocol focusing on the spatial distribution of the sample by land-cover class across different cluster sizes and costs of different sampling options, including options not imposing clustering. This protocol also assesses the two-stage design's adequacy for estimating the precision of accuracy estimates for rare land-cover classes. We illustrate the approach using two large-area, regional accuracy assessments from the National Land-Cover Data (NLCD), and describe how the a priorievaluation was used as a decision-making tool when implementing the NLCD design.

  16. A Priori Analysis of a Compressible Flamelet Model using RANS Data for a Dual-Mode Scramjet Combustor

    NASA Technical Reports Server (NTRS)

    Quinlan, Jesse R.; Drozda, Tomasz G.; McDaniel, James C.; Lacaze, Guilhem; Oefelein, Joseph

    2015-01-01

    In an effort to make large eddy simulation of hydrocarbon-fueled scramjet combustors more computationally accessible using realistic chemical reaction mechanisms, a compressible flamelet/progress variable (FPV) model was proposed that extends current FPV model formulations to high-speed, compressible flows. Development of this model relied on observations garnered from an a priori analysis of the Reynolds-Averaged Navier-Stokes (RANS) data obtained for the Hypersonic International Flight Research and Experimentation (HI-FiRE) dual-mode scramjet combustor. The RANS data were obtained using a reduced chemical mechanism for the combustion of a JP-7 surrogate and were validated using avail- able experimental data. These RANS data were then post-processed to obtain, in an a priori fashion, the scalar fields corresponding to an FPV-based modeling approach. In the current work, in addition to the proposed compressible flamelet model, a standard incompressible FPV model was also considered. Several candidate progress variables were investigated for their ability to recover static temperature and major and minor product species. The effects of pressure and temperature on the tabulated progress variable source term were characterized, and model coupling terms embedded in the Reynolds- averaged Navier-Stokes equations were studied. Finally, results for the novel compressible flamelet/progress variable model were presented to demonstrate the improvement attained by modeling the effects of pressure and flamelet boundary conditions on the combustion.

  17. Parametric Study of Urban-Like Topographic Statistical Moments Relevant to a Priori Modelling of Bulk Aerodynamic Parameters

    NASA Astrophysics Data System (ADS)

    Zhu, Xiaowei; Iungo, G. Valerio; Leonardi, Stefano; Anderson, William

    2017-02-01

    For a horizontally homogeneous, neutrally stratified atmospheric boundary layer (ABL), aerodynamic roughness length, z_0, is the effective elevation at which the streamwise component of mean velocity is zero. A priori prediction of z_0 based on topographic attributes remains an open line of inquiry in planetary boundary-layer research. Urban topographies - the topic of this study - exhibit spatial heterogeneities associated with variability of building height, width, and proximity with adjacent buildings; such variability renders a priori, prognostic z_0 models appealing. Here, large-eddy simulation (LES) has been used in an extensive parametric study to characterize the ABL response (and z_0) to a range of synthetic, urban-like topographies wherein statistical moments of the topography have been systematically varied. Using LES results, we determined the hierarchical influence of topographic moments relevant to setting z_0. We demonstrate that standard deviation and skewness are important, while kurtosis is negligible. This finding is reconciled with a model recently proposed by Flack and Schultz (J Fluids Eng 132:041203-1-041203-10, 2010), who demonstrate that z_0 can be modelled with standard deviation and skewness, and two empirical coefficients (one for each moment). We find that the empirical coefficient related to skewness is not constant, but exhibits a dependence on standard deviation over certain ranges. For idealized, quasi-uniform cubic topographies and for complex, fully random urban-like topographies, we demonstrate strong performance of the generalized Flack and Schultz model against contemporary roughness correlations.

  18. A Priori and a Posteriori Dietary Patterns during Pregnancy and Gestational Weight Gain: The Generation R Study

    PubMed Central

    Tielemans, Myrte J.; Erler, Nicole S.; Leermakers, Elisabeth T. M.; van den Broek, Marion; Jaddoe, Vincent W. V.; Steegers, Eric A. P.; Kiefte-de Jong, Jessica C.; Franco, Oscar H.

    2015-01-01

    Abnormal gestational weight gain (GWG) is associated with adverse pregnancy outcomes. We examined whether dietary patterns are associated with GWG. Participants included 3374 pregnant women from a population-based cohort in the Netherlands. Dietary intake during pregnancy was assessed with food-frequency questionnaires. Three a posteriori-derived dietary patterns were identified using principal component analysis: a “Vegetable, oil and fish”, a “Nuts, high-fiber cereals and soy”, and a “Margarine, sugar and snacks” pattern. The a priori-defined dietary pattern was based on national dietary recommendations. Weight was repeatedly measured around 13, 20 and 30 weeks of pregnancy; pre-pregnancy and maximum weight were self-reported. Normal weight women with high adherence to the “Vegetable, oil and fish” pattern had higher early-pregnancy GWG than those with low adherence (43 g/week (95% CI 16; 69) for highest vs. lowest quartile (Q)). Adherence to the “Margarine, sugar and snacks” pattern was associated with a higher prevalence of excessive GWG (OR 1.45 (95% CI 1.06; 1.99) Q4 vs. Q1). Normal weight women with higher scores on the “Nuts, high-fiber cereals and soy” pattern had more moderate GWG than women with lower scores (−0.01 (95% CI −0.02; −0.00) per SD). The a priori-defined pattern was not associated with GWG. To conclude, specific dietary patterns may play a role in early pregnancy but are not consistently associated with GWG. PMID:26569303

  19. Extended artificial neural networks: incorporation of a priori chemical knowledge enables use of ion selective electrodes for in-situ measurement of ions at environmentally relevant levels.

    PubMed

    Mueller, Amy V; Hemond, Harold F

    2013-12-15

    A novel artificial neural network (ANN) architecture is proposed which explicitly incorporates a priori system knowledge, i.e., relationships between output signals, while preserving the unconstrained non-linear function estimator characteristics of the traditional ANN. A method is provided for architecture layout, disabling training on a subset of neurons, and encoding system knowledge into the neuron structure. The novel architecture is applied to raw readings from a chemical sensor multi-probe (electric tongue), comprised of off-the-shelf ion selective electrodes (ISEs), to estimate individual ion concentrations in solutions at environmentally relevant concentrations and containing environmentally representative ion mixtures. Conductivity measurements and the concept of charge balance are incorporated into the ANN structure, resulting in (1) removal of estimation bias typically seen with use of ISEs in mixtures of unknown composition and (2) improvement of signal estimation by an order of magnitude or more for both major and minor constituents relative to use of ISEs as stand-alone sensors and error reduction by 30-50% relative to use of standard ANN models. This method is suggested as an alternative to parameterization of traditional models (e.g., Nikolsky-Eisenman), for which parameters are strongly dependent on both analyte concentration and temperature, and to standard ANN models which have no mechanism for incorporation of system knowledge. Network architecture and weighting are presented for the base case where the dot product can be used to relate ion concentrations to both conductivity and charge balance as well as for an extension to log-normalized data where the model can no longer be represented in this manner. While parameterization in this case study is analyte-dependent, the architecture is generalizable, allowing application of this method to other environmental problems for which mathematical constraints can be explicitly stated. © 2013 Elsevier

  20. Known knowns, known unknowns and unknown unknowns in prokaryotic transposition.

    PubMed

    Siguier, Patricia; Gourbeyre, Edith; Chandler, Michael

    2017-08-01

    Although the phenomenon of transposition has been known for over 60 years, its overarching importance in modifying and streamlining genomes took some time to recognize. In spite of a robust understanding of transposition of some TE, there remain a number of important TE groups with potential high genome impact and unknown transposition mechanisms and yet others, only recently identified by bioinformatics, yet to be formally confirmed as mobile. Here, we point to some areas of limited understanding concerning well established important TE groups with DDE Tpases, to address central gaps in our knowledge of characterised Tn with other types of Tpases and finally, to highlight new potentially mobile DNA species. It is not exhaustive. Examples have been chosen to provide encouragement in the continued exploration of the considerable prokaryotic mobilome especially in light of the current threat to public health posed by the spread of multiple Ab R . Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Towards Improving Satellite Tropospheric NO2 Retrieval Products: Impacts of the spatial resolution and lighting NOx production from the a priori chemical transport model

    NASA Astrophysics Data System (ADS)

    Smeltzer, C. D.; Wang, Y.; Zhao, C.; Boersma, F.

    2009-12-01

    Polar orbiting satellite retrievals of tropospheric nitrogen dioxide (NO2) columns are important to a variety of scientific applications. These NO2 retrievals rely on a priori profiles from chemical transport models and radiative transfer models to derive the vertical columns (VCs) from slant columns measurements. In this work, we compare the retrieval results using a priori profiles from a global model (TM4) and a higher resolution regional model (REAM) at the OMI overpass hour of 1330 local time, implementing the Dutch OMI NO2 (DOMINO) retrieval. We also compare the retrieval results using a priori profiles from REAM model simulations with and without lightning NOx (NO + NO2) production. A priori model resolution and lightning NOx production are both found to have large impact on satellite retrievals by altering the satellite sensitivity to a particular observation by shifting the NO2 vertical distribution interpreted by the radiation model. The retrieved tropospheric NO2 VCs may increase by 25-100% in urban regions and be reduced by 50% in rural regions if the a priori profiles from REAM simulations are used during the retrievals instead of the profiles from TM4 simulations. The a priori profiles with lightning NOx may result in a 25-50% reduction of the retrieved tropospheric NO2 VCs compared to the a priori profiles without lightning. As first priority, a priori vertical NO2 profiles from a chemical transport model with a high resolution, which can better simulate urban-rural NO2 gradients in the boundary layer and make use of observation-based parameterizations of lightning NOx production, should be first implemented to obtain more accurate NO2 retrievals over the United States, where NOx source regions are spatially separated and lightning NOx production is significant. Then as consequence of a priori NO2 profile variabilities resulting from lightning and model resolution dynamics, geostationary satellite, daylight observations would further promote the next

  2. Exploring the Unknown

    ERIC Educational Resources Information Center

    Pallant, Amy; Pryputniewicz, Sarah; Lee, Hee-Sun

    2012-01-01

    Scientists, and science in general, move from the unknown to increasing levels of certainty. Teaching students about science means encouraging them to embrace and investigate the unknown, make reliable scientific claims, justify those claims with evidence, and evaluate the quality of the evidence. In all areas of science--and especially in…

  3. A comparative study of amplitude calibrations for the East Asia VLBI Network: A priori and template spectrum methods

    NASA Astrophysics Data System (ADS)

    Cho, Ilje; Jung, Taehyun; Zhao, Guang-Yao; Akiyama, Kazunori; Sawada-Satoh, Satoko; Kino, Motoki; Byun, Do-Young; Sohn, Bong Won; Shibata, Katsunori M.; Hirota, Tomoya; Niinuma, Kotaro; Yonekura, Yoshinori; Fujisawa, Kenta; Oyama, Tomoaki

    2017-12-01

    We present the results of a comparative study of amplitude calibrations for the East Asia VLBI Network (EAVN) at 22 and 43 GHz using two different methods of an "a priori" and a "template spectrum", particularly on lower declination sources. Using observational data sets of early EAVN observations, we investigated the elevation-dependence of the gain values at seven stations of the KaVA (KVN and VERA Array) and three additional telescopes in Japan (Takahagi 32 m, Yamaguchi 32 m, and Nobeyama 45 m). By comparing the independently obtained gain values based on these two methods, we found that the gain values from each method were consistent within 10% at elevations higher than 10°. We also found that the total flux densities of two images produced from the different amplitude calibrations were in agreement within 10% at both 22 and 43 GHz. By using the template spectrum method, furthermore, the additional radio telescopes can participate in KaVA (i.e., EAVN), giving a notable sensitivity increase. Therefore, our results will constrain the detailed conditions in order to measure the VLBI amplitude reliably using EAVN, and discuss the potential of possible expansion to telescopes comprising EAVN.

  4. Wiener Filtering of Surface EMG with a priori SNR Estimation Toward Myoelectric Control for Neurological Injury Patients

    PubMed Central

    Liu, Jie; Ying, Dongwen; Zhou, Ping

    2014-01-01

    Voluntary surface electromyogram (EMG) signals from neurological injury patients are often corrupted by involuntary background interference or spikes, imposing difficulties for myoelectric control. We present a novel framework to suppress involuntary background spikes during voluntary surface EMG recordings. The framework applies a Wiener filter to restore voluntary surface EMG signals based on tracking a priori signal to noise ratio (SNR) by using the decision-directed method. Semi-synthetic surface EMG signals contaminated by different levels of involuntary background spikes were constructed from a database of surface EMG recordings in a group of spinal cord injury subjects. After the processing, the onset detection of voluntary muscle activity was significantly improved against involuntary background spikes. The magnitude of voluntary surface EMG signals can also be reliably estimated for myoelectric control purpose. Compared with the previous sample entropy analysis for suppressing involuntary background spikes, the proposed framework is characterized by quick and simple implementation, making it more suitable for application in a myoelectric control system toward neurological injury rehabilitation. PMID:25443536

  5. Randomized clinical trials in orthodontics are rarely registered a priori and often published late or not at all.

    PubMed

    Papageorgiou, Spyridon N; Antonoglou, Georgios N; Sándor, George K; Eliades, Theodore

    2017-01-01

    A priori registration of randomized clinical trials is crucial to the transparency and credibility of their findings. Aim of this study was to assess the frequency with which registered and completed randomized trials in orthodontics are published. We searched ClinicalTrials.gov and ISRCTN for registered randomized clinical trials in orthodontics that had been completed up to January 2017 and judged the publication status and date of registered trials using a systematic protocol. Statistical analysis included descriptive statistics, chi-square or Fisher exact tests, and Kaplan-Meier survival estimates. From the 266 orthodontic trials registered up to January 2017, 80 trials had been completed and included in the present study. Among these 80 included trials, the majority (76%) were registered retrospectively, while only 33 (41%) were published at the time. The median time from completion to publication was 20.1 months (interquartile range: 9.1 to 31.6 months), while survival analysis indicated that less than 10% of the trials were published after 5 years from their completion. Finally, 22 (28%) of completed trials remain unpublished even after 5 years from their completion. Publication rates of registered randomized trials in orthodontics remained low, even 5 years after their completion date.

  6. Randomized clinical trials in orthodontics are rarely registered a priori and often published late or not at all

    PubMed Central

    Antonoglou, Georgios N.; Sándor, George K.; Eliades, Theodore

    2017-01-01

    A priori registration of randomized clinical trials is crucial to the transparency and credibility of their findings. Aim of this study was to assess the frequency with which registered and completed randomized trials in orthodontics are published. We searched ClinicalTrials.gov and ISRCTN for registered randomized clinical trials in orthodontics that had been completed up to January 2017 and judged the publication status and date of registered trials using a systematic protocol. Statistical analysis included descriptive statistics, chi-square or Fisher exact tests, and Kaplan-Meier survival estimates. From the 266 orthodontic trials registered up to January 2017, 80 trials had been completed and included in the present study. Among these 80 included trials, the majority (76%) were registered retrospectively, while only 33 (41%) were published at the time. The median time from completion to publication was 20.1 months (interquartile range: 9.1 to 31.6 months), while survival analysis indicated that less than 10% of the trials were published after 5 years from their completion. Finally, 22 (28%) of completed trials remain unpublished even after 5 years from their completion. Publication rates of registered randomized trials in orthodontics remained low, even 5 years after their completion date. PMID:28777820

  7. A priori testing of subgrid-scale models for the velocity-pressure and vorticity-velocity formulations

    NASA Technical Reports Server (NTRS)

    Winckelmans, G. S.; Lund, T. S.; Carati, D.; Wray, A. A.

    1996-01-01

    Subgrid-scale models for Large Eddy Simulation (LES) in both the velocity-pressure and the vorticity-velocity formulations were evaluated and compared in a priori tests using spectral Direct Numerical Simulation (DNS) databases of isotropic turbulence: 128(exp 3) DNS of forced turbulence (Re(sub(lambda))=95.8) filtered, using the sharp cutoff filter, to both 32(exp 3) and 16(exp 3) synthetic LES fields; 512(exp 3) DNS of decaying turbulence (Re(sub(Lambda))=63.5) filtered to both 64(exp 3) and 32(exp 3) LES fields. Gaussian and top-hat filters were also used with the 128(exp 3) database. Different LES models were evaluated for each formulation: eddy-viscosity models, hyper eddy-viscosity models, mixed models, and scale-similarity models. Correlations between exact versus modeled subgrid-scale quantities were measured at three levels: tensor (traceless), vector (solenoidal 'force'), and scalar (dissipation) levels, and for both cases of uniform and variable coefficient(s). Different choices for the 1/T scaling appearing in the eddy-viscosity were also evaluated. It was found that the models for the vorticity-velocity formulation produce higher correlations with the filtered DNS data than their counterpart in the velocity-pressure formulation. It was also found that the hyper eddy-viscosity model performs better than the eddy viscosity model, in both formulations.

  8. 'Aussie normals': an a priori study to develop clinical chemistry reference intervals in a healthy Australian population.

    PubMed

    Koerbin, G; Cavanaugh, J A; Potter, J M; Abhayaratna, W P; West, N P; Glasgow, N; Hawkins, C; Armbruster, D; Oakman, C; Hickman, P E

    2015-02-01

    Development of reference intervals is difficult, time consuming, expensive and beyond the scope of most laboratories. The Aussie Normals study is a direct a priori study to determine reference intervals in healthy Australian adults. All volunteers completed a health and lifestyle questionnaire and exclusion was based on conditions such as pregnancy, diabetes, renal or cardiovascular disease. Up to 91 biochemical analyses were undertaken on a variety of analytical platforms using serum samples collected from 1856 volunteers. We report on our findings for 40 of these analytes and two calculated parameters performed on the Abbott ARCHITECTci8200/ci16200 analysers. Not all samples were analysed for all assays due to volume requirements or assay/instrument availability. Results with elevated interference indices and those deemed unsuitable after clinical evaluation were removed from the database. Reference intervals were partitioned based on the method of Harris and Boyd into three scenarios, combined gender, males and females and age and gender. We have performed a detailed reference interval study on a healthy Australian population considering the effects of sex, age and body mass. These reference intervals may be adapted to other manufacturer's analytical methods using method transference.

  9. Tomographic image via background subtraction using an x-ray projection image and a priori computed tomography

    SciTech Connect

    Zhang Jin; Yi Byongyong; Lasio, Giovanni

    Kilovoltage x-ray projection images (kV images for brevity) are increasingly available in image guided radiotherapy (IGRT) for patient positioning. These images are two-dimensional (2D) projections of a three-dimensional (3D) object along the x-ray beam direction. Projecting a 3D object onto a plane may lead to ambiguities in the identification of anatomical structures and to poor contrast in kV images. Therefore, the use of kV images in IGRT is mainly limited to bony landmark alignments. This work proposes a novel subtraction technique that isolates a slice of interest (SOI) from a kV image with the assistance of a priori information frommore » a previous CT scan. The method separates structural information within a preselected SOI by suppressing contributions to the unprocessed projection from out-of-SOI-plane structures. Up to a five-fold increase in the contrast-to-noise ratios (CNRs) was observed in selected regions of the isolated SOI, when compared to the original unprocessed kV image. The tomographic image via background subtraction (TIBS) technique aims to provide a quick snapshot of the slice of interest with greatly enhanced image contrast over conventional kV x-ray projections for fast and accurate image guidance of radiation therapy. With further refinements, TIBS could, in principle, provide real-time tumor localization using gantry-mounted x-ray imaging systems without the need for implanted markers.« less

  10. Trial-by-Trial Changes in a Priori Informational Value of External Cues and Subjective Expectancies in Human Auditory Attention

    PubMed Central

    Arjona, Antonio; Gómez, Carlos M.

    2011-01-01

    Background Preparatory activity based on a priori probabilities generated in previous trials and subjective expectancies would produce an attentional bias. However, preparation can be correct (valid) or incorrect (invalid) depending on the actual target stimulus. The alternation effect refers to the subjective expectancy that a target will not be repeated in the same position, causing RTs to increase if the target location is repeated. The present experiment, using the Posner's central cue paradigm, tries to demonstrate that not only the credibility of the cue, but also the expectancy about the next position of the target are changedin a trial by trial basis. Sequences of trials were analyzed. Results The results indicated an increase in RT benefits when sequences of two and three valid trials occurred. The analysis of errors indicated an increase in anticipatory behavior which grows as the number of valid trials is increased. On the other hand, there was also an RT benefit when a trial was preceded by trials in which the position of the target changed with respect to the current trial (alternation effect). Sequences of two alternations or two repetitions were faster than sequences of trials in which a pattern of repetition or alternation is broken. Conclusions Taken together, these results suggest that in Posner's central cue paradigm, and with regard to the anticipatory activity, the credibility of the external cue and of the endogenously anticipated patterns of target location are constantly updated. The results suggest that Bayesian rules are operating in the generation of anticipatory activity as a function of the previous trial's outcome, but also on biases or prior beliefs like the “gambler fallacy”. PMID:21698164

  11. A priori assumptions about characters as a cause of incongruence between molecular and morphological hypotheses of primate interrelationships.

    PubMed

    Tornow, Matthew A; Skelton, Randall R

    2012-01-01

    When molecules and morphology produce incongruent hypotheses of primate interrelationships, the data are typically viewed as incompatible, and molecular hypotheses are often considered to be better indicators of phylogenetic history. However, it has been demonstrated that the choice of which taxa to include in cladistic analysis as well as assumptions about character weighting, character state transformation order, and outgroup choice all influence hypotheses of relationships and may positively influence tree topology, so that relationships between extant taxa are consistent with those found using molecular data. Thus, the source of incongruence between morphological and molecular trees may lie not in the morphological data themselves but in assumptions surrounding the ways characters evolve and their impact on cladistic analysis. In this study, we investigate the role that assumptions about character polarity and transformation order play in creating incongruence between primate phylogenies based on morphological data and those supported by multiple lines of molecular data. By releasing constraints imposed on published morphological analyses of primates from disparate clades and subjecting those data to parsimony analysis, we test the hypothesis that incongruence between morphology and molecules results from inherent flaws in morphological data. To quantify the difference between incongruent trees, we introduce a new method called branch slide distance (BSD). BSD mitigates many of the limitations attributed to other tree comparison methods, thus allowing for a more accurate measure of topological similarity. We find that releasing a priori constraints on character behavior often produces trees that are consistent with molecular trees. Case studies are presented that illustrate how congruence between molecules and unconstrained morphological data may provide insight into issues of polarity, transformation order, homology, and homoplasy.

  12. Phillips-Tikhonov regularization with a priori information for neutron emission tomographic reconstruction on Joint European Torus

    SciTech Connect

    Bielecki, J.; Scholz, M.; Drozdowicz, K.

    A method of tomographic reconstruction of the neutron emissivity in the poloidal cross section of the Joint European Torus (JET, Culham, UK) tokamak was developed. Due to very limited data set (two projection angles, 19 lines of sight only) provided by the neutron emission profile monitor (KN3 neutron camera), the reconstruction is an ill-posed inverse problem. The aim of this work consists in making a contribution to the development of reliable plasma tomography reconstruction methods that could be routinely used at JET tokamak. The proposed method is based on Phillips-Tikhonov regularization and incorporates a priori knowledge of the shape ofmore » normalized neutron emissivity profile. For the purpose of the optimal selection of the regularization parameters, the shape of normalized neutron emissivity profile is approximated by the shape of normalized electron density profile measured by LIDAR or high resolution Thomson scattering JET diagnostics. In contrast with some previously developed methods of ill-posed plasma tomography reconstruction problem, the developed algorithms do not include any post-processing of the obtained solution and the physical constrains on the solution are imposed during the regularization process. The accuracy of the method is at first evaluated by several tests with synthetic data based on various plasma neutron emissivity models (phantoms). Then, the method is applied to the neutron emissivity reconstruction for JET D plasma discharge #85100. It is demonstrated that this method shows good performance and reliability and it can be routinely used for plasma neutron emissivity reconstruction on JET.« less

  13. Local digital control of power electronic converters in a dc microgrid based on a-priori derivation of switching surfaces

    NASA Astrophysics Data System (ADS)

    Banerjee, Bibaswan

    In power electronic basedmicrogrids, the computational requirements needed to implement an optimized online control strategy can be prohibitive. The work presented in this dissertation proposes a generalized method of derivation of geometric manifolds in a dc microgrid that is based on the a-priori computation of the optimal reactions and trajectories for classes of events in a dc microgrid. The proposed states are the stored energies in all the energy storage elements of the dc microgrid and power flowing into them. It is anticipated that calculating a large enough set of dissimilar transient scenarios will also span many scenarios not specifically used to develop the surface. These geometric manifolds will then be used as reference surfaces in any type of controller, such as a sliding mode hysteretic controller. The presence of switched power converters in microgrids involve different control actions for different system events. The control of the switch states of the converters is essential for steady state and transient operations. A digital memory look-up based controller that uses a hysteretic sliding mode control strategy is an effective technique to generate the proper switch states for the converters. An example dcmicrogrid with three dc-dc boost converters and resistive loads is considered for this work. The geometric manifolds are successfully generated for transient events, such as step changes in the loads and the sources. The surfaces corresponding to a specific case of step change in the loads are then used as reference surfaces in an EEPROM for experimentally validating the control strategy. The required switch states corresponding to this specific transient scenario are programmed in the EEPROM as a memory table. This controls the switching of the dc-dc boost converters and drives the system states to the reference manifold. In this work, it is shown that this strategy effectively controls the system for a transient condition such as step changes

  14. Practical Considerations about Expected A Posteriori Estimation in Adaptive Testing: Adaptive A Priori, Adaptive Correction for Bias, and Adaptive Integration Interval.

    ERIC Educational Resources Information Center

    Raiche, Gilles; Blais, Jean-Guy

    In a computerized adaptive test (CAT), it would be desirable to obtain an acceptable precision of the proficiency level estimate using an optimal number of items. Decreasing the number of items is accompanied, however, by a certain degree of bias when the true proficiency level differs significantly from the a priori estimate. G. Raiche (2000) has…

  15. A priori and a posteriori approaches for finding genes of evolutionary interest in non-model species: osmoregulatory genes in the kidney transcriptome of the desert rodent Dipodomys spectabilis (banner-tailed kangaroo rat).

    PubMed

    Marra, Nicholas J; Eo, Soo Hyung; Hale, Matthew C; Waser, Peter M; DeWoody, J Andrew

    2012-12-01

    One common goal in evolutionary biology is the identification of genes underlying adaptive traits of evolutionary interest. Recently next-generation sequencing techniques have greatly facilitated such evolutionary studies in species otherwise depauperate of genomic resources. Kangaroo rats (Dipodomys sp.) serve as exemplars of adaptation in that they inhabit extremely arid environments, yet require no drinking water because of ultra-efficient kidney function and osmoregulation. As a basis for identifying water conservation genes in kangaroo rats, we conducted a priori bioinformatics searches in model rodents (Mus musculus and Rattus norvegicus) to identify candidate genes with known or suspected osmoregulatory function. We then obtained 446,758 reads via 454 pyrosequencing to characterize genes expressed in the kidney of banner-tailed kangaroo rats (Dipodomys spectabilis). We also determined candidates a posteriori by identifying genes that were overexpressed in the kidney. The kangaroo rat sequences revealed nine different a priori candidate genes predicted from our Mus and Rattus searches, as well as 32 a posteriori candidate genes that were overexpressed in kidney. Mutations in two of these genes, Slc12a1 and Slc12a3, cause human renal diseases that result in the inability to concentrate urine. These genes are likely key determinants of physiological water conservation in desert rodents. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Improvement of Tidal Analysis Results by a Priori Rain Fall Modelling at the Vienna and Membach stations

    NASA Astrophysics Data System (ADS)

    Meurers, B.; van Camp, M.; Petermans, T.

    2005-12-01

    We investigate how far tidal analysis results can be improved when a rain fall admittance model is applied on the superconducting gravity (SG) data. For that purpose both Vienna and Membach data have been analysed with and without a priori rain fall correction. In Membach the residual drop for most events (80%) can be explained by the rain water load, while in Vienna only 50% of all events fit the model in detail. In the other cases the Newtonian effect of vertical air mass redistribution (vertical density variation without air pressure change), predominantly connected with high vertical convection activity, e.g. thunderstorms, plays an essential role: short-term atmospheric signals show up steep gravity residual decreases of a few nms-2 within 10 - 60 min, well correlated with outdoor air temperature in most cases. However, even in those cases the water load model is able to explain the dominating part of the residual drop especially during heavy rain fall. In Vienna more than 110 events have been detected over 10 years. 84% of them are associated with heavy rain starting at or up to 10 min later than the residual drop while the rest (16%) shows no or only little rainfall. The magnitude of the gravity drop depends on the total amount of rainfall accumulated during the meteorological event. Step like signals deteriorate the frequency spectrum estimates. This even holds for tidal analysis. As the drops are of physical origin, they should not be eliminated blindly but corrected using water load modeling constrained by high temporal resolution (1 min) rain data. 3D modeling of the water mass load due to a rain event is based on the following assumptions: (1) Rain water intrudes into the uppermost soil layer (close to the topography surface) and remains there at least until rain has stopped. This is justified for a period of some hours after the rainfall as evapotranspiration is not yet effective. (2) No run-off except of sealed areas or building roofs, where water can

  17. 16. Photocopy of photograph (Photographer unknown, Date unknown) SUPPOSED OLDEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Photocopy of photograph (Photographer unknown, Date unknown) SUPPOSED OLDEST VIEW OF MAIN AND EAST ELEVATIONS - Caleb Pusey House, 15 Race Street (Landingford Plantation), Upland, Delaware County, PA

  18. 40 CFR - Unknown Title

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Section Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) AMBIENT AIR MONITORING REFERENCE AND EQUIVALENT METHODS Procedures for Determining Comparability Between Candidate Methods and Reference Method...

  19. Farmer knowledge and a priori risk analysis: pre-release evaluation of genetically modified Roundup Ready wheat across the Canadian prairies.

    PubMed

    Mauro, Ian J; McLachlan, Stéphane M; Van Acker, Rene C

    2009-09-01

    The controversy over the world's first genetically modified (GM) wheat, Roundup Ready wheat (RRW), challenged the efficacy of 'science-based' risk assessment, largely because it excluded the public, particularly farmers, from meaningful input. Risk analysis, in contrast, is broader in orientation as it incorporates scientific data as well as socioeconomic, ethical, and legal concerns, and considers expert and lay input in decision-making. Local knowledge (LK) of farmers is experience-based and represents a rich and reliable source of information regarding the impacts associated with agricultural technology, thereby complementing the scientific data normally used in risk assessment. The overall goal of this study was to explore the role of farmer LK in the a priori risk analysis of RRW. In 2004, data were collected from farmers using mail surveys sent across the three prairie provinces (i.e., Manitoba, Saskatchewan, and Alberta) in western Canada. A stratified random sampling approach was used whereby four separate sampling districts were identified in regions where wheat was grown for each province. Rural post offices were randomly selected in each sampling district using Canada Post databases such that no one post office exceeded 80 farms and that each sampling district comprised 225-235 test farms (n = 11,040). In total, 1,814 people responded, representing an adjusted response rate for farmers of 33%. A subsequent telephone survey showed there was no non-response bias. The primary benefits associated with RRW were associated with weed control, whereas risks emphasized the importance of market harm, corporate control, agronomic problems, and the likelihood of contamination. Overall, risks were ranked much higher than benefits, and the great majority of farmers were highly critical of RRW commercialization. In total, 83.2% of respondents disagreed that RRW should have unconfined release into the environment. Risk was associated with distrust in government and

  20. Building a 3D faulted a priori model for stratigraphic inversion: Illustration of a new methodology applied on a North Sea field case study

    NASA Astrophysics Data System (ADS)

    Rainaud, Jean-François; Clochard, Vincent; Delépine, Nicolas; Crabié, Thomas; Poudret, Mathieu; Perrin, Michel; Klein, Emmanuel

    2018-07-01

    Accurate reservoir characterization is needed all along the development of an oil and gas field study. It helps building 3D numerical reservoir simulation models for estimating the original oil and gas volumes in place and for simulating fluid flow behaviors. At a later stage of the field development, reservoir characterization can also help deciding which recovery techniques need to be used for fluids extraction. In complex media, such as faulted reservoirs, flow behavior predictions within volumes close to faults can be a very challenging issue. During the development plan, it is necessary to determine which types of communication exist between faults or which potential barriers exist for fluid flows. The solving of these issues rests on accurate fault characterization. In most cases, faults are not preserved along reservoir characterization workflows. The memory of the interpreted faults from seismic is not kept during seismic inversion and further interpretation of the result. The goal of our study is at first to integrate a 3D fault network as a priori information into a model-based stratigraphic inversion procedure. Secondly, we apply our methodology on a well-known oil and gas case study over a typical North Sea field (UK Northern North Sea) in order to demonstrate its added value for determining reservoir properties. More precisely, the a priori model is composed of several geological units populated by physical attributes, they are extrapolated from well log data following the deposition mode, but usually a priori model building methods respect neither the 3D fault geometry nor the stratification dips on the fault sides. We address this difficulty by applying an efficient flattening method for each stratigraphic unit in our workflow. Even before seismic inversion, the obtained stratigraphic model has been directly used to model synthetic seismic on our case study. Comparisons between synthetic seismic obtained from our 3D fault network model give much

  1. [Badminton--unknown sport].

    PubMed

    Zekan-Petrinović, Lidija

    2007-01-01

    For a long time, badminton was considered to be only a slow and light game for children, a game that is played outdoors and is structurally undemanding.Today, it is not an unknown and unrecognised sport, especially after it was included into the Olympics Games in 1992. Badminton is one of the oldest sports in the world. It is suitable for all ages (for children and elderly equally), women and men and even handicapped persons. Beginners can start playing badminton matches early because the basics are learned quickly. As a recreational activity, badminton is very popular in Zagreb. In the last 10 years, a number of halls specialized for badminton or offering badminton as one of available sports activities have been opened in Zagreb. At present, there are over 70 professional playgrounds for training of top contestants but also for the citizens who can play recreational badminton.

  2. Sequencing the Unknown

    NASA Image and Video Library

    2017-12-19

    Being able to identify microbes in real time aboard the International Space Station, without having to send them back to Earth for identification first, would be revolutionary for the world of microbiology and space exploration, and the Genes in Space-3 team turned that possibility into a reality this year when it completed the first-ever sample-to-sequence process entirely aboard the space station. This advance could aid in the ability to diagnose and treat astronaut ailments in real time, as well as assisting in the identification of DNA-based life on other planets. It could also benefit other experiments aboard the orbiting laboratory. HD Download: https://archive.org/details/jsc2017m001160_Sequencing_the_Unknown _______________________________________ FOLLOW THE SPACE STATION! Twitter: https://twitter.com/Space_Station Facebook: https://www.facebook.com/ISS Instagram: https://instagram.com/iss/

  3. Locally optimal control under unknown dynamics with learnt cost function: application to industrial robot positioning

    NASA Astrophysics Data System (ADS)

    Guérin, Joris; Gibaru, Olivier; Thiery, Stéphane; Nyiri, Eric

    2017-01-01

    Recent methods of Reinforcement Learning have enabled to solve difficult, high dimensional, robotic tasks under unknown dynamics using iterative Linear Quadratic Gaussian control theory. These algorithms are based on building a local time-varying linear model of the dynamics from data gathered through interaction with the environment. In such tasks, the cost function is often expressed directly in terms of the state and control variables so that it can be locally quadratized to run the algorithm. If the cost is expressed in terms of other variables, a model is required to compute the cost function from the variables manipulated. We propose a method to learn the cost function directly from the data, in the same way as for the dynamics. This way, the cost function can be defined in terms of any measurable quantity and thus can be chosen more appropriately for the task to be carried out. With our method, any sensor information can be used to design the cost function. We demonstrate the efficiency of this method through simulating, with the V-REP software, the learning of a Cartesian positioning task on several industrial robots with different characteristics. The robots are controlled in joint space and no model is provided a priori. Our results are compared with another model free technique, consisting in writing the cost function as a state variable.

  4. 7. Photocopy of painting (Source unknown, Date unknown) EXTERIOR SOUTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Photocopy of painting (Source unknown, Date unknown) EXTERIOR SOUTH FRONT VIEW OF MISSION AND CONVENTO AFTER 1913 - Mission San Francisco Solano de Sonoma, First & Spain Streets, Sonoma, Sonoma County, CA

  5. 6. Photocopy of photograph Photographer unknown, date unknown DETAIL OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Photocopy of photograph Photographer unknown, date unknown DETAIL OF BOTTOM OF DRUM, SHOWING DECORATIVE MOLDING OF DRUM AND ARCHES: NOTE EFFECT OF BOX BEAMS CREATED BY MOLDING - University of Kentucky, Carnegie Library, Lexington, Fayette County, KY

  6. [Profamilia: immense unknown contribution].

    PubMed

    Ramirez Ocampo, J

    1990-12-01

    In late 1965, when he presented himself to the International Planned Parenthood Federation headquarters in London weeks after founding the Profamilia Foundation, Dr. Fernando Tamayo was an unknown Colombian physician with a mission to modify Colombia's very rapid rate of population growth. Colombia in 1964 has a population of 17.5 million growing at an annual rate of 3.4%. By 1973, the population was 22.9 million and growing at 2.7%. Cultural, religious, and moral obstacles precluded an aggressive family planning campaign, which would have aroused violent resistance. Profamilia personnel worked discreetly but persistently, convinced that they would see few short term results but that their effect would be immense in the long run. Family planning is partly a process of educating families in the health, socioeconomic, and psychological benefits of smaller families. Profamilia has a centralized organization which administers 3 main programs, the clinical program with 40 traditional clinics in major cities and 8 well-accepted male clinics, the sterilization program in clinics and mobile units, and the community-based distribution program which distributes pills, condoms, and IUDs through 3000 community posts under the direction of 120 instructors. Between 1964-90, Colombia's total fertility rate declined from 9.2 to 4.4 in rural areas, from 5.2 to 2.2 in urban areas, and from 7.0 to 2.8 overall. The rate of population growth declined from 3.4 to 1.8%. It has been estimated that over half the decline is due to Profamilia services. The total investment by Profamilia during its history was US $100 million. The average cost of protecting a couple against unwanted pregnancy is US $5.26 per year. Colombia's population is projected to increase from 30 to 54 million between 1985 and 2025 even if the growth rate declines from 1.8% in 1990 to 1.3% in 2025. The most worrisome aspect of the projected growth is its concentration in urban areas, which are already beset by poverty

  7. [Gloves: some unknowns].

    PubMed

    Checchi, L; D'Achille, C; Conti, S

    1991-01-01

    The diffusion of transmissible diseases such as the Acquired Immunodeficiency Syndrome, well known as AIDS, has induced in the population a great sensibility to the problem of disease transmission. Dentists and patients, because of peculiar features of oral environment and dental procedures, are very exposed to these risks. For this reason every technique which reduces the risk of cross-infections patient to patient and patient to dentist to patient are absolutely necessary. From this point of view the use of gloves is very important to protect dental operator and patients. The aim of this study is: a) to stress the importance of mechanical barriers, like gloves, in dentistry in order to sensitize dental practitioners to the use of gloves; b) to underline that the quality of dental gloves in Italy is lower than in other countries which have a quality standard.

  8. Combined use of a priori data for fast system self-calibration of a non-rigid multi-camera fringe projection system

    NASA Astrophysics Data System (ADS)

    Stavroulakis, Petros I.; Chen, Shuxiao; Sims-Waterhouse, Danny; Piano, Samanta; Southon, Nicholas; Bointon, Patrick; Leach, Richard

    2017-06-01

    In non-rigid fringe projection 3D measurement systems, where either the camera or projector setup can change significantly between measurements or the object needs to be tracked, self-calibration has to be carried out frequently to keep the measurements accurate1. In fringe projection systems, it is common to use methods developed initially for photogrammetry for the calibration of the camera(s) in the system in terms of extrinsic and intrinsic parameters. To calibrate the projector(s) an extra correspondence between a pre-calibrated camera and an image created by the projector is performed. These recalibration steps are usually time consuming and involve the measurement of calibrated patterns on planes, before the actual object can continue to be measured after a motion of a camera or projector has been introduced in the setup and hence do not facilitate fast 3D measurement of objects when frequent experimental setup changes are necessary. By employing and combining a priori information via inverse rendering, on-board sensors, deep learning and leveraging a graphics processor unit (GPU), we assess a fine camera pose estimation method which is based on optimising the rendering of a model of a scene and the object to match the view from the camera. We find that the success of this calibration pipeline can be greatly improved by using adequate a priori information from the aforementioned sources.

  9. Optimization of Decision-Making for Spatial Sampling in the North China Plain, Based on Remote-Sensing a Priori Knowledge

    NASA Astrophysics Data System (ADS)

    Feng, J.; Bai, L.; Liu, S.; Su, X.; Hu, H.

    2012-07-01

    In this paper, the MODIS remote sensing data, featured with low-cost, high-timely and moderate/low spatial resolutions, in the North China Plain (NCP) as a study region were firstly used to carry out mixed-pixel spectral decomposition to extract an useful regionalized indicator parameter (RIP) (i.e., an available ratio, that is, fraction/percentage, of winter wheat planting area in each pixel as a regionalized indicator variable (RIV) of spatial sampling) from the initial selected indicators. Then, the RIV values were spatially analyzed, and the spatial structure characteristics (i.e., spatial correlation and variation) of the NCP were achieved, which were further processed to obtain the scalefitting, valid a priori knowledge or information of spatial sampling. Subsequently, founded upon an idea of rationally integrating probability-based and model-based sampling techniques and effectively utilizing the obtained a priori knowledge or information, the spatial sampling models and design schemes and their optimization and optimal selection were developed, as is a scientific basis of improving and optimizing the existing spatial sampling schemes of large-scale cropland remote sensing monitoring. Additionally, by the adaptive analysis and decision strategy the optimal local spatial prediction and gridded system of extrapolation results were able to excellently implement an adaptive report pattern of spatial sampling in accordance with report-covering units in order to satisfy the actual needs of sampling surveys.

  10. Comparison of a priori versus provisional heparin therapy on radial artery occlusion after transradial coronary angiography and patent hemostasis (from the PHARAOH Study).

    PubMed

    Pancholy, Samir B; Bertrand, Olivier F; Patel, Tejas

    2012-07-15

    Systemic anticoagulation decreases the risk of radial artery occlusion (RAO) after transradial catheterization and standard occlusive hemostasis. We compared the efficacy and safety of provisional heparin use only when the technique of patent hemostasis was not achievable to standard a priori heparin administration after radial sheath introduction. Patients referred for coronary angiography were randomized in 2 groups. In the a priori group, 200 patients received intravenous heparin (50 IU/kg) immediately after sheath insertion. In the provisional group, 200 patients did not receive heparin during the procedure. After sheath removal, hemostasis was obtained using a TR band (Terumo corporation, Tokyo, Japan) with a plethysmography-guided patent hemostasis technique. In the provisional group, no heparin was given if radial artery patency could be obtained and maintained. If radial patency was not achieved, a bolus of heparin (50 IU/kg) was given. Radial artery patency was evaluated at 24 hours (early RAO) and 30 days after the procedure (late RAO) by plethysmography. Patent hemostasis was obtained in 67% in the a priori group and 74% in the provisional group (p = 0.10). Incidence of RAO remained similar in the 2 groups at the early (7.5% vs 7.0%, p = 0.84) and late (4.5% vs 5.0%, p = 0.83) evaluations. Women, patients with diabetes, patients having not received heparin, and patients without radial artery patency during hemostasis had more RAO. By multivariate analysis, patent radial artery during hemostasis (odds ratio [OR] 0.03, 95% confidence interval [CI] 0.004 to 0.28, p = 0.002) and diabetes (OR 11, 95% CI 3 to 38,p <0.0001) were independent predictors of late RAO, whereas heparin was not (OR 0.45 95% CI 0.13 to 1.54, p = 0.20). In conclusion, our results suggest that maintenance of radial artery patency during hemostasis is the most important parameter to decrease the risk of RAO. In selected cases, provisional use of heparin appears feasible and safe when

  11. 396. Delineator Unknown Date Unknown STATE OF CALIFORNIA; DEPARTMENT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    396. Delineator Unknown Date Unknown STATE OF CALIFORNIA; DEPARTMENT OF PUBLIC WORKS; SAN FRANCISCO - OAKLAND BAY BRIDGE; EAST BAY CROSSING; CANTILEVER STRUCTURE; DETAILS I; DRG. NO. 68 - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  12. 413. Delineator Unknown Date Unknown STATE OF CALIFORNIA; DEPARTMENT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    413. Delineator Unknown Date Unknown STATE OF CALIFORNIA; DEPARTMENT OF PUBLIC WORKS; DIVISION OF SAN FRANCISCO BAY TOLL CROSSINGS; SAN FRANCISCO OAKLAND BAY BRIDGE RECONSTRUCTION; STEEL WORK - WEST BAY; CONTINUOUS SPANS - LONGITUDINAL GIRDERS; SHEET NO. 18; DRAWING NO. C-4028-18R - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  13. 393. Delineator Unknown Date Unknown STATE OF CALIFORNIA; DEPARTMENT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    393. Delineator Unknown Date Unknown STATE OF CALIFORNIA; DEPARTMENT OF PUBLIC WORKS; SAN FRANCISCO - OAKLAND BAY BRIDGE; EAST BAY CROSSING; PIER-E3; GENERAL DETAILS; DRG. NO. 47 - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  14. 414. Delineator Unknown Date Unknown STATE OF CALIFORNIA; DEPARTMENT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    414. Delineator Unknown Date Unknown STATE OF CALIFORNIA; DEPARTMENT OF PUBLIC WORKS; DIVISION OF SAN FRANCISCO BAY TOLL CROSSINGS; SAN FRANCISCO OAKLAND BAY BRIDGE RECONSTRUCTION; STEEL WORK - WEST BAY; TYPICAL SECTIONS; SHEET NO. 5; DRAWING NO. C-4028-5R - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  15. 397. Delineator Unknown Date Unknown STATE OF CALIFORNIA; DEPARTMENT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    397. Delineator Unknown Date Unknown STATE OF CALIFORNIA; DEPARTMENT OF PUBLIC WORKS; SAN FRANCISCO - OAKLAND BAY BRIDGE; EAST BAY CROSSING; CANTILEVER STRUCTURE; DETAILS II; DRG. NO. 69 - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  16. 398. Delineator Unknown Date Unknown STATE OF CALIFORNIA; DEPARTMENT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    398. Delineator Unknown Date Unknown STATE OF CALIFORNIA; DEPARTMENT OF PUBLIC WORKS; SAN FRANCISCO - OAKLAND BAY BRIDGE; EAST BAY CROSSING; GENERAL PLAN; TOWER E-9; DRG. NO. 59 - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  17. 400. Delineator Unknown Date Unknown STATE OF CALIFORNIA; DEPARTMENT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    400. Delineator Unknown Date Unknown STATE OF CALIFORNIA; DEPARTMENT OF PUBLIC WORKS; SAN FRANCISCO - OAKLAND BAY BRIDGE; EAST BAY CROSSING; PIER E-6 TO E-23; TYPICAL DETAILS; DRG. NO. 52 - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  18. Effect of filter type on the statistics of energy transfer between resolved and subfilter scales from a-priori analysis of direct numerical simulations of isotropic turbulence

    NASA Astrophysics Data System (ADS)

    Buzzicotti, M.; Linkmann, M.; Aluie, H.; Biferale, L.; Brasseur, J.; Meneveau, C.

    2018-02-01

    The effects of different filtering strategies on the statistical properties of the resolved-to-subfilter scale (SFS) energy transfer are analysed in forced homogeneous and isotropic turbulence. We carry out a-priori analyses of the statistical characteristics of SFS energy transfer by filtering data obtained from direct numerical simulations with up to 20483 grid points as a function of the filter cutoff scale. In order to quantify the dependence of extreme events and anomalous scaling on the filter, we compare a sharp Fourier Galerkin projector, a Gaussian filter and a novel class of Galerkin projectors with non-sharp spectral filter profiles. Of interest is the importance of Galilean invariance and we confirm that local SFS energy transfer displays intermittency scaling in both skewness and flatness as a function of the cutoff scale. Furthermore, we quantify the robustness of scaling as a function of the filtering type.

  19. 415. Delineator Unknown Date Unknown STATE OF CALIFORNIA; DEPARTMENT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    415. Delineator Unknown Date Unknown STATE OF CALIFORNIA; DEPARTMENT OF PUBLIC WORKS; DIVISION OF SAN FRANCISCO BAY TOLL CROSSINGS; SAN FRANCISCO OAKLAND BAY BRIDGE RECONSTRUCTION; STEEL WORK - WEST BAY; Y.B. ANCHORAGE - FLOOR BEAMS YA-5 AND BENT 3; SHEET NO. 22; DRAWING NO. C-4028-22R - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  20. Identification of dietary patterns associated with obesity in a nationally representative survey of Canadian adults: application of a priori, hybrid, and simplified dietary pattern techniques.

    PubMed

    Jessri, Mahsa; Wolfinger, Russell D; Lou, Wendy Y; L'Abbé, Mary R

    2017-03-01

    Background: Analyzing the effects of dietary patterns is an important approach for examining the complex role of nutrition in the etiology of obesity and chronic diseases. Objectives: The objectives of this study were to characterize the dietary patterns of Canadians with the use of a priori, hybrid, and simplified dietary pattern techniques, and to compare the associations of these patterns with obesity risk in individuals with and without chronic diseases (unhealthy and healthy obesity). Design: Dietary recalls from 11,748 participants (≥18 y of age) in the cross-sectional, nationally representative Canadian Community Health Survey 2.2 were used. A priori dietary pattern was characterized with the use of the previously validated 2015 Dietary Guidelines for Americans Adherence Index (DGAI). Weighted partial least squares (hybrid method) was used to derive an energy-dense (ED), high-fat (HF), low-fiber density (LFD) dietary pattern with the use of 38 food groups. The associations of derived dietary patterns with disease outcomes were then tested with the use of multinomial logistic regression. Results: An ED, HF, and LFD dietary pattern had high positive loadings for fast foods, carbonated drinks, and refined grains, and high negative loadings for whole fruits and vegetables (≥|0.17|). Food groups with a high loading were summed to form a simplified dietary pattern score. Moving from the first (healthiest) to the fourth (least healthy) quartiles of the ED, HF, and LFD pattern and the simplified dietary pattern scores was associated with increasingly elevated ORs for unhealthy obesity, with individuals in quartile 4 having an OR of 2.57 (95% CI: 1.75, 3.76) and 2.73 (95% CI: 1.88, 3.98), respectively ( P -trend < 0.0001). Individuals who adhered the most to the 2015 DGAI recommendations (quartile 4) had a 53% lower OR of unhealthy obesity ( P -trend < 0.0001). The associations of dietary patterns with healthy obesity and unhealthy nonobesity were weaker, albeit

  1. Unknown foundation determination for scour.

    DOT National Transportation Integrated Search

    2012-04-01

    Unknown foundations affect about 9,000 bridges in Texas. For bridges over rivers, this creates a problem : regarding scour decisions as the calculated scour depth cannot be compared to the foundation depth, and a : very conservative costly approach m...

  2. Learned navigation in unknown terrains: A retraction method

    NASA Technical Reports Server (NTRS)

    Rao, Nageswara S. V.; Stoltzfus, N.; Iyengar, S. Sitharama

    1989-01-01

    The problem of learned navigation of a circular robot R, of radius delta (is greater than or equal to 0), through a terrain whose model is not a-priori known is considered. Two-dimensional finite-sized terrains populated by an unknown (but, finite) number of simple polygonal obstacles are also considered. The number and locations of the vertices of each obstacle are unknown to R. R is equipped with a sensor system that detects all vertices and edges that are visible from its present location. In this context two problems are covered. In the visit problem, the robot is required to visit a sequence of destination points, and in the terrain model acquisition problem, the robot is required to acquire the complete model of the terrain. An algorithmic framework is presented for solving these two problems using a retraction of the freespace onto the Voronoi diagram of the terrain. Algorithms are then presented to solve the visit problem and the terrain model acquisition problem.

  3. Using models to guide field experiments: a priori predictions for the CO2 response of a nutrient- and water-limited native Eucalypt woodland.

    PubMed

    Medlyn, Belinda E; De Kauwe, Martin G; Zaehle, Sönke; Walker, Anthony P; Duursma, Remko A; Luus, Kristina; Mishurov, Mikhail; Pak, Bernard; Smith, Benjamin; Wang, Ying-Ping; Yang, Xiaojuan; Crous, Kristine Y; Drake, John E; Gimeno, Teresa E; Macdonald, Catriona A; Norby, Richard J; Power, Sally A; Tjoelker, Mark G; Ellsworth, David S

    2016-08-01

    The response of terrestrial ecosystems to rising atmospheric CO2 concentration (Ca ), particularly under nutrient-limited conditions, is a major uncertainty in Earth System models. The Eucalyptus Free-Air CO2 Enrichment (EucFACE) experiment, recently established in a nutrient- and water-limited woodland presents a unique opportunity to address this uncertainty, but can best do so if key model uncertainties have been identified in advance. We applied seven vegetation models, which have previously been comprehensively assessed against earlier forest FACE experiments, to simulate a priori possible outcomes from EucFACE. Our goals were to provide quantitative projections against which to evaluate data as they are collected, and to identify key measurements that should be made in the experiment to allow discrimination among alternative model assumptions in a postexperiment model intercomparison. Simulated responses of annual net primary productivity (NPP) to elevated Ca ranged from 0.5 to 25% across models. The simulated reduction of NPP during a low-rainfall year also varied widely, from 24 to 70%. Key processes where assumptions caused disagreement among models included nutrient limitations to growth; feedbacks to nutrient uptake; autotrophic respiration; and the impact of low soil moisture availability on plant processes. Knowledge of the causes of variation among models is now guiding data collection in the experiment, with the expectation that the experimental data can optimally inform future model improvements. © 2016 John Wiley & Sons Ltd.

  4. Using models to guide field experiments: a priori predictions for the CO 2 response of a nutrient- and water-limited native Eucalypt woodland

    DOE PAGES

    Medlyn, Belinda E.; De Kauwe, Martin G.; Zaehle, Sönke; ...

    2016-05-09

    One major uncertainty in Earth System models is the response of terrestrial ecosystems to rising atmospheric CO 2 concentration (Ca), particularly under nutrient-lim- ited conditions. The Eucalyptus Free-Air CO 2 Enrichment (EucFACE) experiment, recently established in a nutrient- and water-limited woodlands, presents a unique opportunity to address this uncertainty, but can best do so if key model uncertainties have been identified in advance. Moreover, we applied seven vegetation models, which have previously been comprehensively assessed against earlier forest FACE experi- ments, to simulate a priori possible outcomes from EucFACE. Our goals were to provide quantitative projections against which to evaluatemore » data as they are collected, and to identify key measurements that should be made in the experiment to allow discrimination among alternative model assumptions in a postexperiment model intercompari- son. Simulated responses of annual net primary productivity (NPP) to elevated Ca ranged from 0.5 to 25% across models. The simulated reduction of NPP during a low-rainfall year also varied widely, from 24 to 70%. Key processes where assumptions caused disagreement among models included nutrient limitations to growth; feedbacks to nutri- ent uptake; autotrophic respiration; and the impact of low soil moisture availability on plant processes. Finally, knowledge of the causes of variation among models is now guiding data collection in the experiment, with the expectation that the experimental data can optimally inform future model improvements.« less

  5. Using models to guide field experiments: a priori predictions for the CO 2 response of a nutrient- and water-limited native Eucalypt woodland

    SciTech Connect

    Medlyn, Belinda E.; De Kauwe, Martin G.; Zaehle, Sönke

    One major uncertainty in Earth System models is the response of terrestrial ecosystems to rising atmospheric CO 2 concentration (Ca), particularly under nutrient-lim- ited conditions. The Eucalyptus Free-Air CO 2 Enrichment (EucFACE) experiment, recently established in a nutrient- and water-limited woodlands, presents a unique opportunity to address this uncertainty, but can best do so if key model uncertainties have been identified in advance. Moreover, we applied seven vegetation models, which have previously been comprehensively assessed against earlier forest FACE experi- ments, to simulate a priori possible outcomes from EucFACE. Our goals were to provide quantitative projections against which to evaluatemore » data as they are collected, and to identify key measurements that should be made in the experiment to allow discrimination among alternative model assumptions in a postexperiment model intercompari- son. Simulated responses of annual net primary productivity (NPP) to elevated Ca ranged from 0.5 to 25% across models. The simulated reduction of NPP during a low-rainfall year also varied widely, from 24 to 70%. Key processes where assumptions caused disagreement among models included nutrient limitations to growth; feedbacks to nutri- ent uptake; autotrophic respiration; and the impact of low soil moisture availability on plant processes. Finally, knowledge of the causes of variation among models is now guiding data collection in the experiment, with the expectation that the experimental data can optimally inform future model improvements.« less

  6. Kinetic analysis of hyperpolarized data with minimum a priori knowledge: Hybrid maximum entropy and nonlinear least squares method (MEM/NLS).

    PubMed

    Mariotti, Erika; Veronese, Mattia; Dunn, Joel T; Southworth, Richard; Eykyn, Thomas R

    2015-06-01

    To assess the feasibility of using a hybrid Maximum-Entropy/Nonlinear Least Squares (MEM/NLS) method for analyzing the kinetics of hyperpolarized dynamic data with minimum a priori knowledge. A continuous distribution of rates obtained through the Laplace inversion of the data is used as a constraint on the NLS fitting to derive a discrete spectrum of rates. Performance of the MEM/NLS algorithm was assessed through Monte Carlo simulations and validated by fitting the longitudinal relaxation time curves of hyperpolarized [1-(13) C] pyruvate acquired at 9.4 Tesla and at three different flip angles. The method was further used to assess the kinetics of hyperpolarized pyruvate-lactate exchange acquired in vitro in whole blood and to re-analyze the previously published in vitro reaction of hyperpolarized (15) N choline with choline kinase. The MEM/NLS method was found to be adequate for the kinetic characterization of hyperpolarized in vitro time-series. Additional insights were obtained from experimental data in blood as well as from previously published (15) N choline experimental data. The proposed method informs on the compartmental model that best approximate the biological system observed using hyperpolarized (13) C MR especially when the metabolic pathway assessed is complex or a new hyperpolarized probe is used. © 2014 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc.

  7. A priori and a posteriori investigations for developing large eddy simulations of multi-species turbulent mixing under high-pressure conditions

    SciTech Connect

    Borghesi, Giulio; Bellan, Josette, E-mail: josette.bellan@jpl.nasa.gov; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109-8099

    2015-03-15

    A Direct Numerical Simulation (DNS) database was created representing mixing of species under high-pressure conditions. The configuration considered is that of a temporally evolving mixing layer. The database was examined and analyzed for the purpose of modeling some of the unclosed terms that appear in the Large Eddy Simulation (LES) equations. Several metrics are used to understand the LES modeling requirements. First, a statistical analysis of the DNS-database large-scale flow structures was performed to provide a metric for probing the accuracy of the proposed LES models as the flow fields obtained from accurate LESs should contain structures of morphology statisticallymore » similar to those observed in the filtered-and-coarsened DNS (FC-DNS) fields. To characterize the morphology of the large-scales structures, the Minkowski functionals of the iso-surfaces were evaluated for two different fields: the second-invariant of the rate of deformation tensor and the irreversible entropy production rate. To remove the presence of the small flow scales, both of these fields were computed using the FC-DNS solutions. It was found that the large-scale structures of the irreversible entropy production rate exhibit higher morphological complexity than those of the second invariant of the rate of deformation tensor, indicating that the burden of modeling will be on recovering the thermodynamic fields. Second, to evaluate the physical effects which must be modeled at the subfilter scale, an a priori analysis was conducted. This a priori analysis, conducted in the coarse-grid LES regime, revealed that standard closures for the filtered pressure, the filtered heat flux, and the filtered species mass fluxes, in which a filtered function of a variable is equal to the function of the filtered variable, may no longer be valid for the high-pressure flows considered in this study. The terms requiring modeling are the filtered pressure, the filtered heat flux, the filtered pressure

  8. Genetic basis of delay discounting in frequent gamblers: examination of a priori candidates and exploration of a panel of dopamine-related loci

    PubMed Central

    Gray, Joshua C; MacKillop, James

    2014-01-01

    Introduction Delay discounting is a behavioral economic index of impulsivity that reflects preferences for small immediate rewards relative to larger delayed rewards. It has been consistently linked to pathological gambling and other forms of addictive behavior, and has been proposed to be a behavioral characteristic that may link genetic variation and risk of developing addictive disorders (i.e., an endophenotype). Studies to date have revealed significant associations with polymorphisms associated with dopamine neurotransmission. The current study examined associations between delay discounting and both previously linked variants and a novel panel of dopamine-related variants in a sample of frequent gamblers. Methods Participants were 175 weekly gamblers of European ancestry who completed the Monetary Choice Questionnaire to assess delay discounting preferences and provided a DNA via saliva. Results In a priori tests, two loci previously associated with delayed reward discounting (rs1800497 and rs4680) were not replicated, however, the long form of DRD4 VNTR was significantly associated with lower discounting of delayed rewards. Exploratory analysis of the dopamine-related panel revealed 11 additional significant associations in genes associated with dopamine synthesis, breakdown, reuptake, and receptor function (DRD3, SLC6A3, DDC, DBH, and SLC18A2). An aggregate genetic risk score from the nominally significant loci accounted for 17% of the variance in discounting. Mediational analyses largely supported the presence of indirect effects between the associated loci, delay discounting, and pathological gambling severity. Conclusions These findings do not replicate previously reported associations but identify several novel candidates and provide preliminary support for a systems biology approach to understand the genetic basis of delay discounting. PMID:25365808

  9. Learning from the Unknown Student

    ERIC Educational Resources Information Center

    Barlow, Angela T.; Gerstenschlager, Natasha E.; Harmon, Shannon E.

    2016-01-01

    In this article, three instructional situations demonstrate the value of using an "unknown" student's work to allow the advancement of students' mathematical thinking as well as their engagement in the mathematical practice of critiquing the reasoning of others: (1) introducing alternative solution strategies; (2) critiquing inaccuracies…

  10. An Approach for the Long-Term 30-m Land Surface Snow-Free Albedo Retrieval from Historic Landsat Surface Reflectance and MODIS-based A Priori Anisotropy Knowledge

    NASA Technical Reports Server (NTRS)

    Shuai, Yanmin; Masek, Jeffrey G.; Gao, Feng; Schaaf, Crystal B.; He, Tao

    2014-01-01

    Land surface albedo has been recognized by the Global Terrestrial Observing System (GTOS) as an essential climate variable crucial for accurate modeling and monitoring of the Earth's radiative budget. While global climate studies can leverage albedo datasets from MODIS, VIIRS, and other coarse-resolution sensors, many applications in heterogeneous environments can benefit from higher-resolution albedo products derived from Landsat. We previously developed a "MODIS-concurrent" approach for the 30-meter albedo estimation which relied on combining post-2000 Landsat data with MODIS Bidirectional Reflectance Distribution Function (BRDF) information. Here we present a "pre-MODIS era" approach to extend 30-m surface albedo generation in time back to the 1980s, through an a priori anisotropy Look-Up Table (LUT) built up from the high quality MCD43A BRDF estimates over representative homogenous regions. Each entry in the LUT reflects a unique combination of land cover, seasonality, terrain information, disturbance age and type, and Landsat optical spectral bands. An initial conceptual LUT was created for the Pacific Northwest (PNW) of the United States and provides BRDF shapes estimated from MODIS observations for undisturbed and disturbed surface types (including recovery trajectories of burned areas and non-fire disturbances). By accepting the assumption of a generally invariant BRDF shape for similar land surface structures as a priori information, spectral white-sky and black-sky albedos are derived through albedo-to-nadir reflectance ratios as a bridge between the Landsat and MODIS scale. A further narrow-to-broadband conversion based on radiative transfer simulations is adopted to produce broadband albedos at visible, near infrared, and shortwave regimes.We evaluate the accuracy of resultant Landsat albedo using available field measurements at forested AmeriFlux stations in the PNW region, and examine the consistency of the surface albedo generated by this approach

  11. Digital tomosynthesis mammography: intra- and interplane artifact reduction for high-contrast objects on reconstructed slices using a priori 3D geometrical information

    NASA Astrophysics Data System (ADS)

    Ge, Jun; Chan, Heang-Ping; Sahiner, Berkman; Zhang, Yiheng; Wei, Jun; Hadjiiski, Lubomir M.; Zhou, Chuan

    2007-03-01

    We are developing a computerized technique to reduce intra- and interplane ghosting artifacts caused by high-contrast objects such as dense microcalcifications (MCs) or metal markers on the reconstructed slices of digital tomosynthesis mammography (DTM). In this study, we designed a constrained iterative artifact reduction method based on a priori 3D information of individual MCs. We first segmented individual MCs on projection views (PVs) using an automated MC detection system. The centroid and the contrast profile of the individual MCs in the 3D breast volume were estimated from the backprojection of the segmented individual MCs on high-resolution (0.1 mm isotropic voxel size) reconstructed DTM slices. An isolated volume of interest (VOI) containing one or a few MCs is then modeled as a high-contrast object embedded in a local homogeneous background. A shift-variant 3D impulse response matrix (IRM) of the projection-reconstruction (PR) system for the extracted VOI was calculated using the DTM geometry and the reconstruction algorithm. The PR system for this VOI is characterized by a system of linear equations. A constrained iterative method was used to solve these equations for the effective linear attenuation coefficients (eLACs) within the isolated VOI. Spatial constraint and positivity constraint were used in this method. Finally, the intra- and interplane artifacts on the whole breast volume resulting from the MC were calculated using the corresponding impulse responses and subsequently subtracted from the original reconstructed slices. The performance of our artifact-reduction method was evaluated using a computer-simulated MC phantom, as well as phantom images and patient DTMs obtained with IRB approval. A GE prototype DTM system that acquires 21 PVs in 3º increments over a +/-30º range was used for image acquisition in this study. For the computer-simulated MC phantom, the eLACs can be estimated accurately, thus the interplane artifacts were

  12. A retrospective cohort study on the risk of stroke in relation to a priori health knowledge level among people with type 2 diabetes mellitus in Taiwan.

    PubMed

    Lai, Yun-Ju; Hu, Hsiao-Yun; Lee, Ya-Ling; Ku, Po-Wen; Yen, Yung-Feng; Chu, Dachen

    2017-05-22

    Intervention of diabetes care education with regular laboratory check-up in outpatient visits showed long-term benefits to reduce the risk of macrovascular complications among people with type 2 diabetes. However, research on the level of a priori health knowledge to the prevention of diabetic complications in community settings has been scarce. We therefore aimed to investigate the association of health knowledge and stroke incidence in patients with type 2 diabetes in Taiwan. A nationally representative sample of general Taiwanese population was selected using a multistage systematic sampling process from Taiwan National Health Interview Survey (NHIS) in 2005. Subjects were interviewed by a standardized face-to-face questionnaire in the survey, obtaining information of demographics, socioeconomic status, family medical history, obesity, health behaviors, and 15-item health knowledge assessment. The NHIS dataset was linked to Taiwan National Health Insurance claims data to retrieve the diagnosis of type 2 diabetes in NHIS participants at baseline and identify follow-up incidence of stroke from 2005 to 2013. Univariate and multivariate Cox regressions were used to estimate the effect of baseline health knowledge level to the risk of stroke incidence among this group of people with type 2 diabetes. A total of 597 diabetic patients with a mean age of 51.28 years old and nearly half of males were analyzed. During the 9-year follow-up period, 65 new stroke cases were identified among them. Kaplan-Meier curves comparing the three groups of low/moderate/high knowledge levels revealed a statistical significance (p-value of log-rank test <0.01). After controlling for potential confounders, comparing to the group of low health knowledge level, the relative risk of stroke was significantly lower for those with moderate (adjusted hazard ratio [AHR] = 0.63; 95% CI, 0.33-1.19; p-value = 0.15) and high level of health knowledge (AHR = 0.43; 95% CI, 0.22-0.86; p

  13. Neuro-adaptive backstepping control of SISO non-affine systems with unknown gain sign.

    PubMed

    Ramezani, Zahra; Arefi, Mohammad Mehdi; Zargarzadeh, Hassan; Jahed-Motlagh, Mohammad Reza

    2016-11-01

    This paper presents two neuro-adaptive controllers for a class of uncertain single-input, single-output (SISO) nonlinear non-affine systems with unknown gain sign. The first approach is state feedback controller, so that a neuro-adaptive state-feedback controller is constructed based on the backstepping technique. The second approach is an observer-based controller and K-filters are designed to estimate the system states. The proposed method relaxes a priori knowledge of control gain sign and therefore by utilizing the Nussbaum-type functions this problem is addressed. In these methods, neural networks are employed to approximate the unknown nonlinear functions. The proposed adaptive control schemes guarantee that all the closed-loop signals are semi-globally uniformly ultimately bounded (SGUUB). Finally, the theoretical results are numerically verified through simulation examples. Simulation results show the effectiveness of the proposed methods. Copyright © 2016 ISA. All rights reserved.

  14. Turbulent transport and mixing in transitional Rayleigh-Taylor unstable flow: A priori assessment of gradient-diffusion and similarity modeling

    NASA Astrophysics Data System (ADS)

    Schilling, Oleg; Mueschke, Nicholas J.

    2017-12-01

    Data from a 1152 ×760 ×1280 direct numerical simulation [N. J. Mueschke and O. Schilling, Phys. Fluids 21, 014106 (2009), 10.1063/1.3064120] of a Rayleigh-Taylor mixing layer modeled after a small-Atwood-number water-channel experiment is used to investigate the validity of gradient diffusion and similarity closures a priori. The budgets of the mean flow, turbulent kinetic energy, turbulent kinetic energy dissipation rate, heavy-fluid mass fraction variance, and heavy-fluid mass fraction variance dissipation rate transport equations across the mixing layer were previously analyzed [O. Schilling and N. J. Mueschke, Phys. Fluids 22, 105102 (2010), 10.1063/1.3484247] at different evolution times to identify the most important transport and mixing mechanisms. Here a methodology is introduced to systematically estimate model coefficients as a function of time in the closures of the dynamically significant terms in the transport equations by minimizing the L2 norm of the difference between the model and correlations constructed using the simulation data. It is shown that gradient-diffusion and similarity closures used for the turbulent kinetic energy K , turbulent kinetic energy dissipation rate ɛ , heavy-fluid mass fraction variance S , and heavy-fluid mass fraction variance dissipation rate χ equations capture the shape of the exact, unclosed profiles well over the nonlinear and turbulent evolution regimes. Using order-of-magnitude estimates [O. Schilling and N. J. Mueschke, Phys. Fluids 22, 105102 (2010), 10.1063/1.3484247] for the terms in the exact transport equations and their closure models, it is shown that several of the standard closures for the turbulent production and dissipation (destruction) must be modified to include Reynolds-number scalings appropriate for Rayleigh-Taylor flow at small to intermediate Reynolds numbers. The late-time, large Reynolds number coefficients are determined to be different from those used in shear flow applications and

  15. [Focal myositis: An unknown disease].

    PubMed

    Gallay, L; Streichenberger, N; Benveniste, O; Allenbach, Y

    2017-10-01

    Focal myositis are inflammatory muscle diseases of unknown origin. At the opposite from the other idiopathic inflammatory myopathies, they are restricted to a single muscle or to a muscle group. They are not associated with extramuscular manifestations, and they have a good prognosis without any treatment. They are characterized by a localized swelling affecting mostly lower limbs. The pseudo-tumor can be painful, but is not associated with a muscle weakness. Creatine kinase level is normal. Muscle MRI shows an inflammation restricted to a muscle or a muscle group. Muscle biopsy and pathological analysis remain necessary for the diagnosis, showing inflammatory infiltrates composed by macrophages and lymphocytes without any specific distribution within the muscle. Focal overexpression of HLA-1 by the muscle fibers is frequently observed. The muscle biopsy permits to rule out differential diagnosis such a malignancy (sarcoma). Spontaneous remission occurs within weeks or months after the first symptoms, relapse is unusual. Copyright © 2017. Published by Elsevier SAS.

  16. Previously unknown species of Aspergillus.

    PubMed

    Gautier, M; Normand, A-C; Ranque, S

    2016-08-01

    The use of multi-locus DNA sequence analysis has led to the description of previously unknown 'cryptic' Aspergillus species, whereas classical morphology-based identification of Aspergillus remains limited to the section or species-complex level. The current literature highlights two main features concerning these 'cryptic' Aspergillus species. First, the prevalence of such species in clinical samples is relatively high compared with emergent filamentous fungal taxa such as Mucorales, Scedosporium or Fusarium. Second, it is clearly important to identify these species in the clinical laboratory because of the high frequency of antifungal drug-resistant isolates of such Aspergillus species. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently been shown to enable the identification of filamentous fungi with an accuracy similar to that of DNA sequence-based methods. As MALDI-TOF MS is well suited to the routine clinical laboratory workflow, it facilitates the identification of these 'cryptic' Aspergillus species at the routine mycology bench. The rapid establishment of enhanced filamentous fungi identification facilities will lead to a better understanding of the epidemiology and clinical importance of these emerging Aspergillus species. Based on routine MALDI-TOF MS-based identification results, we provide original insights into the key interpretation issues of a positive Aspergillus culture from a clinical sample. Which ubiquitous species that are frequently isolated from air samples are rarely involved in human invasive disease? Can both the species and the type of biological sample indicate Aspergillus carriage, colonization or infection in a patient? Highly accurate routine filamentous fungi identification is central to enhance the understanding of these previously unknown Aspergillus species, with a vital impact on further improved patient care. Copyright © 2016 European Society of Clinical Microbiology and

  17. The potential implications of reclaimed wastewater reuse for irrigation on the agricultural environment: The knowns and unknowns of the fate of antibiotics and antibiotic resistant bacteria and resistance genes - A review.

    PubMed

    Christou, Anastasis; Agüera, Ana; Bayona, Josep Maria; Cytryn, Eddie; Fotopoulos, Vasileios; Lambropoulou, Dimitra; Manaia, Célia M; Michael, Costas; Revitt, Mike; Schröder, Peter; Fatta-Kassinos, Despo

    2017-10-15

    The use of reclaimed wastewater (RWW) for the irrigation of crops may result in the continuous exposure of the agricultural environment to antibiotics, antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). In recent years, certain evidence indicate that antibiotics and resistance genes may become disseminated in agricultural soils as a result of the amendment with manure and biosolids and irrigation with RWW. Antibiotic residues and other contaminants may undergo sorption/desorption and transformation processes (both biotic and abiotic), and have the potential to affect the soil microbiota. Antibiotics found in the soil pore water (bioavailable fraction) as a result of RWW irrigation may be taken up by crop plants, bioaccumulate within plant tissues and subsequently enter the food webs; potentially resulting in detrimental public health implications. It can be also hypothesized that ARGs can spread among soil and plant-associated bacteria, a fact that may have serious human health implications. The majority of studies dealing with these environmental and social challenges related with the use of RWW for irrigation were conducted under laboratory or using, somehow, controlled conditions. This critical review discusses the state of the art on the fate of antibiotics, ARB and ARGs in agricultural environment where RWW is applied for irrigation. The implications associated with the uptake of antibiotics by plants (uptake mechanisms) and the potential risks to public health are highlighted. Additionally, knowledge gaps as well as challenges and opportunities are addressed, with the aim of boosting future research towards an enhanced understanding of the fate and implications of these contaminants of emerging concern in the agricultural environment. These are key issues in a world where the increasing water scarcity and the continuous appeal of circular economy demand answers for a long-term safe use of RWW for irrigation. Copyright © 2017 Elsevier

  18. Estimation of the Arrival Time and Duration of a Radio Signal with Unknown Amplitude and Initial Phase

    NASA Astrophysics Data System (ADS)

    Trifonov, A. P.; Korchagin, Yu. E.; Korol'kov, S. V.

    2018-05-01

    We synthesize the quasi-likelihood, maximum-likelihood, and quasioptimal algorithms for estimating the arrival time and duration of a radio signal with unknown amplitude and initial phase. The discrepancies between the hardware and software realizations of the estimation algorithm are shown. The characteristics of the synthesized-algorithm operation efficiency are obtained. Asymptotic expressions for the biases, variances, and the correlation coefficient of the arrival-time and duration estimates, which hold true for large signal-to-noise ratios, are derived. The accuracy losses of the estimates of the radio-signal arrival time and duration because of the a priori ignorance of the amplitude and initial phase are determined.

  19. Damage diagnosis algorithm using a sequential change point detection method with an unknown distribution for damage

    NASA Astrophysics Data System (ADS)

    Noh, Hae Young; Rajagopal, Ram; Kiremidjian, Anne S.

    2012-04-01

    This paper introduces a damage diagnosis algorithm for civil structures that uses a sequential change point detection method for the cases where the post-damage feature distribution is unknown a priori. This algorithm extracts features from structural vibration data using time-series analysis and then declares damage using the change point detection method. The change point detection method asymptotically minimizes detection delay for a given false alarm rate. The conventional method uses the known pre- and post-damage feature distributions to perform a sequential hypothesis test. In practice, however, the post-damage distribution is unlikely to be known a priori. Therefore, our algorithm estimates and updates this distribution as data are collected using the maximum likelihood and the Bayesian methods. We also applied an approximate method to reduce the computation load and memory requirement associated with the estimation. The algorithm is validated using multiple sets of simulated data and a set of experimental data collected from a four-story steel special moment-resisting frame. Our algorithm was able to estimate the post-damage distribution consistently and resulted in detection delays only a few seconds longer than the delays from the conventional method that assumes we know the post-damage feature distribution. We confirmed that the Bayesian method is particularly efficient in declaring damage with minimal memory requirement, but the maximum likelihood method provides an insightful heuristic approach.

  20. Comparative interpretations of renormalization inversion technique for reconstructing unknown emissions from measured atmospheric concentrations

    NASA Astrophysics Data System (ADS)

    Singh, Sarvesh Kumar; Kumar, Pramod; Rani, Raj; Turbelin, Grégory

    2017-04-01

    The study highlights a theoretical comparison and various interpretations of a recent inversion technique, called renormalization, developed for the reconstruction of unknown tracer emissions from their measured concentrations. The comparative interpretations are presented in relation to the other inversion techniques based on principle of regularization, Bayesian, minimum norm, maximum entropy on mean, and model resolution optimization. It is shown that the renormalization technique can be interpreted in a similar manner to other techniques, with a practical choice of a priori information and error statistics, while eliminating the need of additional constraints. The study shows that the proposed weight matrix and weighted Gram matrix offer a suitable deterministic choice to the background error and measurement covariance matrices, respectively, in the absence of statistical knowledge about background and measurement errors. The technique is advantageous since it (i) utilizes weights representing a priori information apparent to the monitoring network, (ii) avoids dependence on background source estimates, (iii) improves on alternative choices for the error statistics, (iv) overcomes the colocalization problem in a natural manner, and (v) provides an optimally resolved source reconstruction. A comparative illustration of source retrieval is made by using the real measurements from a continuous point release conducted in Fusion Field Trials, Dugway Proving Ground, Utah.

  1. Building an environment model using depth information

    NASA Technical Reports Server (NTRS)

    Roth-Tabak, Y.; Jain, Ramesh

    1989-01-01

    Modeling the environment is one of the most crucial issues for the development and research of autonomous robot and tele-perception. Though the physical robot operates (navigates and performs various tasks) in the real world, any type of reasoning, such as situation assessment, planning or reasoning about action, is performed based on information in its internal world. Hence, the robot's intentional actions are inherently constrained by the models it has. These models may serve as interfaces between sensing modules and reasoning modules, or in the case of telerobots serve as interface between the human operator and the distant robot. A robot operating in a known restricted environment may have a priori knowledge of its whole possible work domain, which will be assimilated in its World Model. As the information in the World Model is relatively fixed, an Environment Model must be introduced to cope with the changes in the environment and to allow exploring entirely new domains. Introduced here is an algorithm that uses dense range data collected at various positions in the environment to refine and update or generate a 3-D volumetric model of an environment. The model, which is intended for autonomous robot navigation and tele-perception, consists of cubic voxels with the possible attributes: Void, Full, and Unknown. Experimental results from simulations of range data in synthetic environments are given. The quality of the results show great promise for dealing with noisy input data. The performance measures for the algorithm are defined, and quantitative results for noisy data and positional uncertainty are presented.

  2. Environment.

    ERIC Educational Resources Information Center

    White, Gilbert F.

    1980-01-01

    Presented are perspectives on the emergence of environmental problems. Six major trends in scientific thinking are identified including: holistic approaches to examining environments, life support systems, resource management, risk assessment, streamlined methods for monitoring environmental change, and emphasis on the global framework. (Author/SA)

  3. Neural-network-observer-based optimal control for unknown nonlinear systems using adaptive dynamic programming

    NASA Astrophysics Data System (ADS)

    Liu, Derong; Huang, Yuzhu; Wang, Ding; Wei, Qinglai

    2013-09-01

    In this paper, an observer-based optimal control scheme is developed for unknown nonlinear systems using adaptive dynamic programming (ADP) algorithm. First, a neural-network (NN) observer is designed to estimate system states. Then, based on the observed states, a neuro-controller is constructed via ADP method to obtain the optimal control. In this design, two NN structures are used: a three-layer NN is used to construct the observer which can be applied to systems with higher degrees of nonlinearity and without a priori knowledge of system dynamics, and a critic NN is employed to approximate the value function. The optimal control law is computed using the critic NN and the observer NN. Uniform ultimate boundedness of the closed-loop system is guaranteed. The actor, critic, and observer structures are all implemented in real-time, continuously and simultaneously. Finally, simulation results are presented to demonstrate the effectiveness of the proposed control scheme.

  4. Human-Robot Teams for Unknown and Uncertain Environments

    NASA Technical Reports Server (NTRS)

    Fong, Terry

    2015-01-01

    Man-robot interaction is the study of interactions between humans and robots. It is often referred as HRI by researchers. Human-robot interaction is a multidisciplinary field with contributions from human-computer interaction, artificial intelligence.

  5. Natural Language Direction Following for Robots in Unstructured Unknown Environments

    DTIC Science & Technology

    2015-01-15

    Looking back, I can safely say my most fruitful research was the result of these collaborations. Seeing peers learn and struggle alongside me has been...performance gains on such diverse problems as autonomous driving, playing Super Mario, handwriting recogni- tion, helicopter control, and image...similarity metric between what the direction says and what the robot sees. These are useful to describe the landmark field of the Spatial Description

  6. Navigation through unknown and dynamic open spaces using topological notions

    NASA Astrophysics Data System (ADS)

    Miguel-Tomé, Sergio

    2018-04-01

    Until now, most algorithms used for navigation have had the purpose of directing system towards one point in space. However, humans communicate tasks by specifying spatial relations among elements or places. In addition, the environments in which humans develop their activities are extremely dynamic. The only option that allows for successful navigation in dynamic and unknown environments is making real-time decisions. Therefore, robots capable of collaborating closely with human beings must be able to make decisions based on the local information registered by the sensors and interpret and express spatial relations. Furthermore, when one person is asked to perform a task in an environment, this task is communicated given a category of goals so the person does not need to be supervised. Thus, two problems appear when one wants to create multifunctional robots: how to navigate in dynamic and unknown environments using spatial relations and how to accomplish this without supervision. In this article, a new architecture to address the two cited problems is presented, called the topological qualitative navigation architecture. In previous works, a qualitative heuristic called the heuristic of topological qualitative semantics (HTQS) has been developed to establish and identify spatial relations. However, that heuristic only allows for establishing one spatial relation with a specific object. In contrast, navigation requires a temporal sequence of goals with different objects. The new architecture attains continuous generation of goals and resolves them using HTQS. Thus, the new architecture achieves autonomous navigation in dynamic or unknown open environments.

  7. Carcinoma of Unknown Primary—Patient Version

    Cancer.gov

    Carcinoma of unknown primary (CUP) occurs when cancer cells have spread in the body and formed metastatic tumors but the site of the primary cancer is not known. There are a number of reasons why the primary cancer may not be found. Start here to find treatment information for carcinoma of unknown primary.

  8. SU-F-J-198: A Cross-Platform Adaptation of An a Priori Scatter Correction Algorithm for Cone-Beam Projections to Enable Image- and Dose-Guided Proton Therapy

    SciTech Connect

    Andersen, A; Casares-Magaz, O; Elstroem, U

    Purpose: Cone-beam CT (CBCT) imaging may enable image- and dose-guided proton therapy, but is challenged by image artefacts. The aim of this study was to demonstrate the general applicability of a previously developed a priori scatter correction algorithm to allow CBCT-based proton dose calculations. Methods: The a priori scatter correction algorithm used a plan CT (pCT) and raw cone-beam projections acquired with the Varian On-Board Imager. The projections were initially corrected for bow-tie filtering and beam hardening and subsequently reconstructed using the Feldkamp-Davis-Kress algorithm (rawCBCT). The rawCBCTs were intensity normalised before a rigid and deformable registration were applied on themore » pCTs to the rawCBCTs. The resulting images were forward projected onto the same angles as the raw CB projections. The two projections were subtracted from each other, Gaussian and median filtered, and then subtracted from the raw projections and finally reconstructed to the scatter-corrected CBCTs. For evaluation, water equivalent path length (WEPL) maps (from anterior to posterior) were calculated on different reconstructions of three data sets (CB projections and pCT) of three parts of an Alderson phantom. Finally, single beam spot scanning proton plans (0–360 deg gantry angle in steps of 5 deg; using PyTRiP) treating a 5 cm central spherical target in the pCT were re-calculated on scatter-corrected CBCTs with identical targets. Results: The scatter-corrected CBCTs resulted in sub-mm mean WEPL differences relative to the rigid registration of the pCT for all three data sets. These differences were considerably smaller than what was achieved with the regular Varian CBCT reconstruction algorithm (1–9 mm mean WEPL differences). Target coverage in the re-calculated plans was generally improved using the scatter-corrected CBCTs compared to the Varian CBCT reconstruction. Conclusion: We have demonstrated the general applicability of a priori CBCT scatter

  9. Distributed Lag Models: Examining Associations between the Built Environment and Health

    PubMed Central

    Baek, Jonggyu; Sánchez, Brisa N.; Berrocal, Veronica J.; Sanchez-Vaznaugh, Emma V.

    2016-01-01

    Built environment factors constrain individual level behaviors and choices, and thus are receiving increasing attention to assess their influence on health. Traditional regression methods have been widely used to examine associations between built environment measures and health outcomes, where a fixed, pre-specified spatial scale (e.g., 1 mile buffer) is used to construct environment measures. However, the spatial scale for these associations remains largely unknown and misspecifying it introduces bias. We propose the use of distributed lag models (DLMs) to describe the association between built environment features and health as a function of distance from the locations of interest and circumvent a-priori selection of a spatial scale. Based on simulation studies, we demonstrate that traditional regression models produce associations biased away from the null when there is spatial correlation among the built environment features. Inference based on DLMs is robust under a range of scenarios of the built environment. We use this innovative application of DLMs to examine the association between the availability of convenience stores near California public schools, which may affect children’s dietary choices both through direct access to junk food and exposure to advertisement, and children’s body mass index z-scores (BMIz). PMID:26414942

  10. Fast grasping of unknown objects using principal component analysis

    NASA Astrophysics Data System (ADS)

    Lei, Qujiang; Chen, Guangming; Wisse, Martijn

    2017-09-01

    Fast grasping of unknown objects has crucial impact on the efficiency of robot manipulation especially subjected to unfamiliar environments. In order to accelerate grasping speed of unknown objects, principal component analysis is utilized to direct the grasping process. In particular, a single-view partial point cloud is constructed and grasp candidates are allocated along the principal axis. Force balance optimization is employed to analyze possible graspable areas. The obtained graspable area with the minimal resultant force is the best zone for the final grasping execution. It is shown that an unknown object can be more quickly grasped provided that the component analysis principle axis is determined using single-view partial point cloud. To cope with the grasp uncertainty, robot motion is assisted to obtain a new viewpoint. Virtual exploration and experimental tests are carried out to verify this fast gasping algorithm. Both simulation and experimental tests demonstrated excellent performances based on the results of grasping a series of unknown objects. To minimize the grasping uncertainty, the merits of the robot hardware with two 3D cameras can be utilized to suffice the partial point cloud. As a result of utilizing the robot hardware, the grasping reliance is highly enhanced. Therefore, this research demonstrates practical significance for increasing grasping speed and thus increasing robot efficiency under unpredictable environments.

  11. A Priori Calculations of Thermodynamic Functions

    DTIC Science & Technology

    1991-12-01

    Ten closes this work with a brief summary and offers suggestions for improving the model and for future research. S CHAPTER TWO In this chapter, we...we must first define the theoretical model . The molecules studied in this work contain up to 10 non- hydrogen atoms and, in general, are not...is given by equation (2-31) for two different geometries or two different theoretical models . Equation (2-31) shows the error in the force constant has

  12. Existence conditions for unknown input functional observers

    NASA Astrophysics Data System (ADS)

    Fernando, T.; MacDougall, S.; Sreeram, V.; Trinh, H.

    2013-01-01

    This article presents necessary and sufficient conditions for the existence and design of an unknown input Functional observer. The existence of the observer can be verified by computing a nullspace of a known matrix and testing some matrix rank conditions. The existence of the observer does not require the satisfaction of the observer matching condition (i.e. Equation (16) in Hou and Muller 1992, 'Design of Observers for Linear Systems with Unknown Inputs', IEEE Transactions on Automatic Control, 37, 871-875), is not limited to estimating scalar functionals and allows for arbitrary pole placement. The proposed observer always exists when a state observer exists for the unknown input system, and furthermore, the proposed observer can exist even in some instances when an unknown input state observer does not exist.

  13. Optimization of Biomathematical Model Predictions for Cognitive Performance Impairment in Individuals: Accounting for Unknown Traits and Uncertain States in Homeostatic and Circadian Processes

    PubMed Central

    Van Dongen, Hans P. A.; Mott, Christopher G.; Huang, Jen-Kuang; Mollicone, Daniel J.; McKenzie, Frederic D.; Dinges, David F.

    2007-01-01

    Current biomathematical models of fatigue and performance do not accurately predict cognitive performance for individuals with a priori unknown degrees of trait vulnerability to sleep loss, do not predict performance reliably when initial conditions are uncertain, and do not yield statistically valid estimates of prediction accuracy. These limitations diminish their usefulness for predicting the performance of individuals in operational environments. To overcome these 3 limitations, a novel modeling approach was developed, based on the expansion of a statistical technique called Bayesian forecasting. The expanded Bayesian forecasting procedure was implemented in the two-process model of sleep regulation, which has been used to predict performance on the basis of the combination of a sleep homeostatic process and a circadian process. Employing the two-process model with the Bayesian forecasting procedure to predict performance for individual subjects in the face of unknown traits and uncertain states entailed subject-specific optimization of 3 trait parameters (homeostatic build-up rate, circadian amplitude, and basal performance level) and 2 initial state parameters (initial homeostatic state and circadian phase angle). Prior information about the distribution of the trait parameters in the population at large was extracted from psychomotor vigilance test (PVT) performance measurements in 10 subjects who had participated in a laboratory experiment with 88 h of total sleep deprivation. The PVT performance data of 3 additional subjects in this experiment were set aside beforehand for use in prospective computer simulations. The simulations involved updating the subject-specific model parameters every time the next performance measurement became available, and then predicting performance 24 h ahead. Comparison of the predictions to the subjects' actual data revealed that as more data became available for the individuals at hand, the performance predictions became

  14. Determinants of use and non-use of a web-based communication system in cerebral palsy care: evaluating the association between professionals' system use and their a priori expectancies and background

    PubMed Central

    2011-01-01

    Background Previously we described parents' and professionals' experiences with a web-based communication system in a 6-month pilot in three Dutch cerebral palsy care settings. We found that half of the participating professionals had not used the system, and of those who had used the system one third had used it only once. The present study aimed to evaluate whether professionals' system use was associated with their a priori expectancies and background. Methods Professionals who had not used the system (n = 54) were compared with professionals who had used the system more than once (n = 46) on the basis of their questionnaire responses before the pilot, their affiliation and the number of patients which they represented in the study. The questionnaire items comprised professionals' expectancies regarding the system's performance and ease of use, as well as the expected time availability and integration into daily care practice. Results Overall, users had higher a priori expectancies than non-users. System use was associated with expected ease of use (p = .046) and time availability (p = .005): 50% of the users (vs. 31% of the non-users) expected that the system would be easy to use and 93% of the users (vs. 72% of the non-users) expected that they would be able to reserve a time slot each week for responding to submitted questions. With respect to professionals' affiliation, system use was associated with professionals' institution (p = .003) and discipline (p = .001), with more (para-) medical professionals among users (93% vs. 63% among non-users), and more education professionals among non-users (37% vs. 7% among users). In addition, users represented more patients (mean 2, range 1-8) than non-users (mean 1.1, range 1-2) (p = .000). Conclusions Professionals' system use was associated with expected ease of use and time availability, professionals' affiliation and the number of represented patients, while no association was found with expected performance of

  15. Method for genetic identification of unknown organisms

    DOEpatents

    Colston, Jr., Billy W.; Fitch, Joseph P.; Hindson, Benjamin J.; Carter, Chance J.; Beer, Neil Reginald

    2016-08-23

    A method of rapid, genome and proteome based identification of unknown pathogenic or non-pathogenic organisms in a complex sample. The entire sample is analyzed by creating millions of emulsion encapsulated microdroplets, each containing a single pathogenic or non-pathogenic organism sized particle and appropriate reagents for amplification. Following amplification, the amplified product is analyzed.

  16. Reconstruction of signals with unknown spectra in information field theory with parameter uncertainty

    SciTech Connect

    Ensslin, Torsten A.; Frommert, Mona

    2011-05-15

    The optimal reconstruction of cosmic metric perturbations and other signals requires knowledge of their power spectra and other parameters. If these are not known a priori, they have to be measured simultaneously from the same data used for the signal reconstruction. We formulate the general problem of signal inference in the presence of unknown parameters within the framework of information field theory. To solve this, we develop a generic parameter-uncertainty renormalized estimation (PURE) technique. As a concrete application, we address the problem of reconstructing Gaussian signals with unknown power-spectrum with five different approaches: (i) separate maximum-a-posteriori power-spectrum measurement and subsequentmore » reconstruction, (ii) maximum-a-posteriori reconstruction with marginalized power-spectrum, (iii) maximizing the joint posterior of signal and spectrum, (iv) guessing the spectrum from the variance in the Wiener-filter map, and (v) renormalization flow analysis of the field-theoretical problem providing the PURE filter. In all cases, the reconstruction can be described or approximated as Wiener-filter operations with assumed signal spectra derived from the data according to the same recipe, but with differing coefficients. All of these filters, except the renormalized one, exhibit a perception threshold in case of a Jeffreys prior for the unknown spectrum. Data modes with variance below this threshold do not affect the signal reconstruction at all. Filter (iv) seems to be similar to the so-called Karhune-Loeve and Feldman-Kaiser-Peacock estimators for galaxy power spectra used in cosmology, which therefore should also exhibit a marginal perception threshold if correctly implemented. We present statistical performance tests and show that the PURE filter is superior to the others, especially if the post-Wiener-filter corrections are included or in case an additional scale-independent spectral smoothness prior can be adopted.« less

  17. 14. Photocopy of photograph (source unknown) photographer unknown pre1885 NORTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Photocopy of photograph (source unknown) photographer unknown pre-1885 NORTH SIDE AND WEST FRONT (NOTE ABSENCE OF DORMER ON GAMBREL ROOF OF ELL) (Illustration #6 of Data Report included in Field Records) - Narbonne House, 71 Essex Street, Salem, Essex County, MA

  18. Unified sensor management in unknown dynamic clutter

    NASA Astrophysics Data System (ADS)

    Mahler, Ronald; El-Fallah, Adel

    2010-04-01

    In recent years the first author has developed a unified, computationally tractable approach to multisensor-multitarget sensor management. This approach consists of closed-loop recursion of a PHD or CPHD filter with maximization of a "natural" sensor management objective function called PENT (posterior expected number of targets). In this paper we extend this approach so that it can be used in unknown, dynamic clutter backgrounds.

  19. Hierarchical and non-hierarchical {lambda} elements for one dimensional problems with unknown strength of singularity

    SciTech Connect

    Wong, K.K.; Surana, K.S.

    1996-10-01

    This paper presents a new and general procedure for designing hierarchical and non-hierarchical special elements called {lambda} elements for one dimensional singular problems where the strength of the singularity is unknown. The {lambda} element formulations presented here permit correct numerical simulation of linear as well as non-linear singular problems without a priori knowledge of the strength of the singularity. A procedure is also presented for determining the exact strength of the singularity using the converged solution. It is shown that in special instances, the general formulation of {lambda} elements can also be made hierarchical. The {lambda} elements presented here aremore » of type C{sup 0} and provide C{sup 0} inter-element continuity with p-version elements. One dimensional steady state radial flow of an upper convected Maxwell fluid is considered as a sample problem. Since in this case {lambda}{sub i} are known, this problem provides a good example for investigating the performance of the formulation proposed here. Least squares approach (or Least Squares Finite Element Formulation: LSFEF) is used to construct the integral form (error functional I) from the differential equations. Numerical studies are presented for radially inward flow of an upper convected Maxwell fluid with inner radius r{sub i} = .1 and .01 etc. and Deborah number De = 2.« less

  20. Determination of absorption coefficient of nanofluids with unknown refractive index from reflection and transmission spectra

    NASA Astrophysics Data System (ADS)

    Kim, Joong Bae; Lee, Seungyoon; Lee, Kyungeun; Lee, Ikjin; Lee, Bong Jae

    2018-07-01

    It has been shown that the absorption coefficient of a nanofluid can be actively tuned by changing material, size, shape, and concentration of the nanoparticle suspension. In applications of engineered nanofluids for the direct absorption of solar radiation, it is important to experimentally characterize the absorption coefficient of nanofluids in the solar spectrum. If the refractive index of the base fluid (i.e., the solution without nanoparticles) is known a priori, the absorption coefficient of nanofluids can be easily determined from the transmission spectrum. However, if the refractive index of the base fluid is not known, it is not straightforward to extract the absorption coefficient solely from the transmission spectrum. The present work aims to develop an analytical method of determining the absorption coefficient of nanofluids with unknown refractive index by measuring both reflection and transmission spectra. The proposed method will be validated with deionized water, and the effect of measurement uncertainty will be carefully examined. Finally, the general applicability of the proposed method will also be demonstrated for Therminol VP-1 as well as the Therminol VP-1 - graphite nanofluid.

  1. Multivariate statistical approach to estimate mixing proportions for unknown end members

    USGS Publications Warehouse

    Valder, Joshua F.; Long, Andrew J.; Davis, Arden D.; Kenner, Scott J.

    2012-01-01

    A multivariate statistical method is presented, which includes principal components analysis (PCA) and an end-member mixing model to estimate unknown end-member hydrochemical compositions and the relative mixing proportions of those end members in mixed waters. PCA, together with the Hotelling T2 statistic and a conceptual model of groundwater flow and mixing, was used in selecting samples that best approximate end members, which then were used as initial values in optimization of the end-member mixing model. This method was tested on controlled datasets (i.e., true values of estimates were known a priori) and found effective in estimating these end members and mixing proportions. The controlled datasets included synthetically generated hydrochemical data, synthetically generated mixing proportions, and laboratory analyses of sample mixtures, which were used in an evaluation of the effectiveness of this method for potential use in actual hydrological settings. For three different scenarios tested, correlation coefficients (R2) for linear regression between the estimated and known values ranged from 0.968 to 0.993 for mixing proportions and from 0.839 to 0.998 for end-member compositions. The method also was applied to field data from a study of end-member mixing in groundwater as a field example and partial method validation.

  2. FDG PET detection of unknown primary tumors.

    PubMed

    Bohuslavizki, K H; Klutmann, S; Kröger, S; Sonnemann, U; Buchert, R; Werner, J A; Mester, J; Clausen, M

    2000-05-01

    The management of patients presenting with metastases of unknown primary origin remains a clinical challenge despite a large variety of imaging modalities. The aim of this study was to evaluate FDG PET in detecting the sites of primary cancer in these patients. Fifty-three patients with metastatic cervical adenopathy (n = 44) or extracervical metastases (n = 9) of unknown primary origin were included after extensive but inconclusive conventional diagnostic work-up. Patients received 370 MBq FDG (10 mCi) intravenously, and whole-body images were acquired at 60 min after injection. Clinical, surgical, and histopathologic findings and complete correlative imaging were used to assess the results. In 27 of 53 patients FDG PET showed focal tracer accumulations corresponding to potential primary tumor sites located in the lungs (n = 12), the palatine tonsil (n = 5), the salivary glands (n = 2), the nasopharynx (n = 1), the oropharynx (n = 3), the maxillary sinus (n = 1), and the larynx (n = 1). Moreover, in 2 patients FDG PET revealed lesions suspected to be tumors in the breast and the ileocolonic area. In 20 (37.8%) of these 53 patients FDG PET was true-positive, identifying the primary tumor in the lungs (n = 10), the head and neck region (n = 8), the breast (n = 1), and the ileocolonic area (n = 1). In 6 of 27 patients FDG PET was false-positive, predominantly identifying suspicious areas in the palatine tonsil (n = 3). One patient denied further diagnostic work-up after PET; thus, positive PET could not be evaluated. In 26 of 53 patients PET did not reveal lesions suspected to be the primary. However, primary tumors were not found in these patients at clinical follow-up. FDG PET is a valuable diagnostic tool in patients with cancer of unknown primary because it imaged unknown primary tumors in about one third of all patients investigated. In addition, FDG PET assists in both guiding biopsies for histologic evaluation and selecting the appropriate treatment protocols

  3. Infectious causes of fever of unknown origin.

    PubMed

    McGregor, Alastair C; Moore, David A

    2015-06-01

    The causes of fever of unknown origin (FUO) are changing because advances in clinical practice and diagnostics have facilitated the identification of some infections. A variety of bacterial infections can cause FUO, and these can be divided into those that are easy to identify using culture and those that require serological or molecular tests for identification. A number of viral, parasitic and fungal infections can also cause prolonged fever. This article summarises the clinical features and diagnostic strategy of these infections. © Royal College of Physicians 2015. All rights reserved.

  4. Multiple tendon ruptures of unknown etiology.

    PubMed

    Axibal, Derek P; Anderson, John G

    2013-10-01

    Tendon ruptures are common findings in foot and ankle practice. The etiology of tendon ruptures tends to be multifactorial-usually due to a combination of trauma, effects of systemic diseases, adverse effects of medications, and obesity. We present an unusual case of right Achilles tendinitis, left Achilles tendon rupture, bilateral peroneus longus tendon rupture, and left peroneus brevis tendon rupture of unknown etiology. This case report highlights the need for research for other possible, lesser known etiologies of tendon pathology. Therapeutic, Level IV, Case Study.

  5. Fever of Unknown Origin in Childhood.

    PubMed

    Chusid, Michael J

    2017-02-01

    Childhood fever of unknown origin (FUO) is most often related to an underlying infection but can also be associated with a variety of neoplastic, rheumatologic, and inflammatory conditions. Repeated, focused reviews of patient history and physical examination are often helpful in suggesting a likely diagnosis. Diagnostic workup should be staged, usually leaving invasive testing for last. Advances in molecular genetic techniques have increased the importance of these assays in the diagnosis of FUO in children. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Chronic Traumatic Encephalopathy: Known Causes, Unknown Effects.

    PubMed

    Iacono, Diego; Shively, Sharon B; Edlow, Brian L; Perl, Daniel P

    2017-05-01

    Chronic traumatic encephalopathy (CTE) is a neuropathologic diagnosis typically made in human brains with a history of repetitive traumatic brain injury (rTBI). It remains unknown whether CTE occurs exclusively after rTBI, or whether a single TBI (sTBI) can cause CTE. Similarly, it is unclear whether impact (eg, motor vehicle accidents) and non-impact (eg, blasts) types of energy transfer trigger divergent or common pathologies. While it is established that a history of rTBI increases the risk of multiple neurodegenerative diseases (eg, dementia, parkinsonism, and CTE), the possible pathophysiologic and molecular mechanisms underlying these risks have yet to be elucidated. Published by Elsevier Inc.

  7. Unknown components of the plastidial permeome

    PubMed Central

    Pick, Thea R.; Weber, Andreas P. M.

    2014-01-01

    Beyond their role in photosynthesis plastids provide a plethora of additional metabolic functions to plant cells. For example, they harbor complete biosynthetic pathways for the de novo synthesis of carotenoids, fatty acids, and amino acids. Furthermore plastids contribute important reactions to multi-compartmentalized pathways, such as photorespiration or plant hormone syntheses, and they depend on the import of essential molecules that they cannot synthesize themselves, such as ascorbic acid. This causes a high traffic of metabolites across the plastid envelope. Although it was recently shown that non-polar substrates could be exchanged between the plastid and the ER without involving transporters, various essential transport processes are mediated by highly selective but still unknown metabolite transporters. This review focuses on selected components of the plastidial permeome that are predicted to exist but that have not yet been identified as molecular entities, such as the transporters for isopentenyl diphosphate (IPP) or ascorbic acid. PMID:25191333

  8. Ranging algebraically with more observations than unknowns

    NASA Astrophysics Data System (ADS)

    Awange, J. L.; Fukuda, Y.; Takemoto, S.; Ateya, I. L.; Grafarend, E. W.

    2003-07-01

    In the recently developed Spatial Reference System that is designed to check and control the accuracy of the three-dimensional coordinate measuring machines and tooling equipment (Metronom US., Inc., Ann Arbor: http://www.metronomus.com), the coordinates of the edges of the instrument are computed from distances of the bars. The use of distances in industrial application is fast gaining momentum just as in Geodesy and in Geophysical applications and thus necessitating efficient algorithms to solve the nonlinear distance equations. Whereas the ranging problem with minimum known stations was considered in our previous contribution in the same Journal, the present contribution extends to the case where one is faced with many distance observations than unknowns (overdetermined case) as is usually the case in practise. Using the Gauss-Jacobi Combinatorial approach, we demonstrate how one can proceed to position without reverting to iterative and linearizing procedures such as Newton's or Least Squares approach.

  9. Education Through Exploration: Evaluating the Unknown

    NASA Astrophysics Data System (ADS)

    Anbar, A. D.

    2015-12-01

    Mastery of the peculiar and powerful practices of science is increasingly important for the average citizen. With the rise of the Internet, most of human knowledge is at our fingertips. As content becomes a commodity, success and survival aren't about who knows the most, but who is better able to explore the unknown, actively applying and extending knowledge through critical thinking and hypothesis-driven problem-solving. This applies to the economic livelihoods of individuals and to society at large as we grapple with climate change and other science-infused challenges. Unfortunately, science is too often taught as an encyclopedic collection of settled facts to be mastered rather than as a process of exploration that embraces curiosity, inquiry, testing, and communication to reduce uncertainty about the unknown. This problem is exacerbated by the continued prevalence of teacher-centric pedagogy, which promotes learning-from-authority and passive learning. The initial wave of massively open online courses (MOOCs) generally mimic this teaching style in virtual form. It is hypothesized that emerging digital teaching technologies can help address this challenge at Internet scale in "next generation" MOOCs and flipped classroom experiences. Interactive simulations, immersive virtual field trips, gamified elements, rapid adaptive feedback, intelligent tutoring systems, and personalized pathways, should motivate and enhance learning. Through lab-like projects and tutorials, students should be able to construct knowledge from interactive experiences, modeling the authentic practice of science while mastering complex concepts. Freed from lecturing, teaching staff should be available for direct and intense student-teacher interactions. These claims are difficult to evaluate with traditional assessment instruments, but digital technologies provide powerful new ways to evaluate student learning and learn from student behaviors. We will describe ongoing experiences with such

  10. An Empirical Verification of a-priori Learning Models on Mailing Archives in the Context of Online Learning Activities of Participants in Free\\Libre Open Source Software (FLOSS) Communities

    ERIC Educational Resources Information Center

    Mukala, Patrick; Cerone, Antonio; Turini, Franco

    2017-01-01

    Free\\Libre Open Source Software (FLOSS) environments are increasingly dubbed as learning environments where practical software engineering skills can be acquired. Numerous studies have extensively investigated how knowledge is acquired in these environments through a collaborative learning model that define a learning process. Such a learning…

  11. Unknown Risks: Parental Hesitation about Vaccination.

    PubMed

    Blaisdell, Laura L; Gutheil, Caitlin; Hootsmans, Norbert A M; Han, Paul K J

    2016-05-01

    This qualitative study of a select sample of vaccine-hesitant parents (VHPs) explores perceived and constructed personal judgments about the risks and uncertainties associated with vaccines and vaccine-preventable diseases (VPDs) and how these subjective risk judgments influence parents' decisions about childhood vaccination. The study employed semistructured focus group interviews with 42 VHPs to elicit parents' perceptions and thought processes regarding the risks associated with vaccination and nonvaccination, the sources of these perceptions, and their approach to decision making about vaccination for their children. VHPs engage in various reasoning processes and tend to perceive risks of vaccination as greater than the risks of VPDs. At the same time, VHPs engage in other reasoning processes that lead them to perceive ambiguity in information about the harms of vaccination-citing concerns about the missing, conflicting, changing, or otherwise unreliable nature of information. VHPs' refusal of vaccination may reflect their aversion to both the risk and ambiguity they perceive to be associated with vaccination. Mitigating this vaccine hesitancy likely requires reconstructing the risks and ambiguities associated with vaccination-a challenging task that requires providing parents with meaningful evidence-based information on the known risks of vaccination versus VPDs and explicitly acknowledging the risks that remain truly unknown. © The Author(s) 2015.

  12. Lung Lesions During Fever of Unknown Origin.

    PubMed

    Krupa, Renata; Zielonka, Tadeusz M; Hadzik-Blaszczyk, Malgorzata; Wardyn, Kazimierz A; Zycinska, Katarzyna

    2017-01-01

    Fever of unknown origin (FUO) remains one of the most difficult diagnostic challenges. The causes of FUO can be various diseases located in different organs. The aim of the study was to determine the prevalence and nature of pulmonary lesions during FUO. One hundred and sixty one patients with FUO participated in this prospective study. We performed a detailed comprehensive history, physical examination, and a wide spectrum of tests. The most common causes of FUO were infections (39%), autoimmune conditions (28%), and neoplasms (17%). Lung lesions were found in 30% of patients. In this group 35% were infections, 30% autoimmune diseases, and 4% cancer. Among patients with respiratory infections, there were cases of tuberculosis, atypical pneumonia, lung abscess, and bronchiectases. Autoimmune pulmonary lesions were observed during vasculitis and systemic lupus. The causes of FUO in the group of patients with lung lesions were also pulmonary embolism, sarcoidosis, and pulmonary fibrosis. Chest CT played an important role in the diagnosis of the causes of FUO with pulmonary manifestations. Pulmonary lesions are a common cause of FUO. Most FUO with pulmonary lesions are recognized during infections and autoimmune diseases. An important part of diagnosing FUO is a detailed evaluation of the respiratory system.

  13. Online Solution of Two-Player Zero-Sum Games for Continuous-Time Nonlinear Systems With Completely Unknown Dynamics.

    PubMed

    Fu, Yue; Chai, Tianyou

    2016-12-01

    Regarding two-player zero-sum games of continuous-time nonlinear systems with completely unknown dynamics, this paper presents an online adaptive algorithm for learning the Nash equilibrium solution, i.e., the optimal policy pair. First, for known systems, the simultaneous policy updating algorithm (SPUA) is reviewed. A new analytical method to prove the convergence is presented. Then, based on the SPUA, without using a priori knowledge of any system dynamics, an online algorithm is proposed to simultaneously learn in real time either the minimal nonnegative solution of the Hamilton-Jacobi-Isaacs (HJI) equation or the generalized algebraic Riccati equation for linear systems as a special case, along with the optimal policy pair. The approximate solution to the HJI equation and the admissible policy pair is reexpressed by the approximation theorem. The unknown constants or weights of each are identified simultaneously by resorting to the recursive least square method. The convergence of the online algorithm to the optimal solutions is provided. A practical online algorithm is also developed. Simulation results illustrate the effectiveness of the proposed method.

  14. Uric Acid: The Unknown Uremic Toxin.

    PubMed

    Treviño-Becerra, Alejandro

    2018-01-01

    This review brings together concepts of uric acid metabolism affecting renal parenchyma and its function and the current therapies to reduce hyperuricemia (HyU) and avoid renal disease progression. High uric acid plays an important role in several chronic diseases including kidney diseases such as lithiasis, gout nephropathy, and preeclampsia. In the last 30 years, it has been shown that reducing HyU with low protein and low purine diets in addition to allopurinol creates physiopathological conditions that produce a slight increase in the glomerular filtration rate (GFR). In recent years, in a new era of research in clinical, genetics, pharmacological, and epidemiologic fields, they have been moving forward to support the idea that reduction in HyU could benefit the chronic renal failure (CRF) patients (stage III-IV), thereby avoiding the drop of GFR for undefined mechanisms. There are several clinical trials in progress that show the HyU reducing to very low values and an increased GFR. In a young population, when treating HyU there is a reduction in high blood pressure. There are some reports showing that HyU could play a role in the diabetic nephropathy. Therefore, there have been some speculations that HyU treatment could stop the progression of CRF modifying the natural history of the diseases. So there will be new clinical trials with old and new medication and metabolic procedure to maintain a very low blood levels in the unknown uremic toxin know as uric acid which seems to be the toxin to the damage kidney. © 2018 S. Karger AG, Basel.

  15. Merkel Cell Carcinoma of Unknown Primary Origin

    PubMed Central

    Deneve, Jeremiah L.; Messina, Jane L.; Marzban, Suroosh S.; Gonzalez, Ricardo J.; Walls, Brooke M.; Fisher, Kate J.; Ann Chen, Y.; Wayne Cruse, C.; Sondak, Vernon K.; Zager, Jonathan S.

    2015-01-01

    Background Merkel cell carcinoma (MCC) is a rare neuroendocrine tumor of the skin. MCC from an unknown primary origin (MCCUP) can present a diagnostic and therapeutic challenge. We describe our single-institution experience with the diagnosis and management of MCCUP presenting as metastases to lymph nodes. Methods After institutional review board approval, our institutional database spanning the years 1998–2010 was queried for patients with MCCUP. Clinicopathologic variables and outcomes were assessed. Results From a database of 321 patients with MCC, 38 (12%) were identified as having nodal MCCUP. Median age was 67 years, and 79% were men. Nodal basins involved at presentation were cervical (58%), axillary/epitrochlear (21%), or inguinal/iliac (21%). CK20 staining was positive in 93% of tumors tested, and all were negative for thyroid transcription factor-1. Twenty-nine patients (76%) underwent complete regional lymph node dissection (LND): 3 had LND alone, ten had LND and adjuvant radiotherapy, and 16 underwent LND followed by chemoradiotherapy. Definitive chemoradiotherapy without surgery was provided to six patients (16%), while radiotherapy alone was provided to three (8%). Recurrence was observed in 34% of patients. Median recurrence-free survival was 35 months. Ten patients (26%) died, five of disease and five of other causes. The median overall survival was 104 months. Conclusions Nodal MCCUP is a rare disease affecting primarily elderly white men. Recurrence is observed in approximately one-third of patients, with a 104 month median overall survival after a multimodal treatment approach consisting of surgery along with adjuvant chemotherapy and radiotherapy in the majority of patients. PMID:22271206

  16. Spacecraft Internal Acoustic Environment Modeling

    NASA Technical Reports Server (NTRS)

    Chu, SShao-sheng R.; Allen, Christopher S.

    2009-01-01

    Acoustic modeling can be used to identify key noise sources, determine/analyze sub-allocated requirements, keep track of the accumulation of minor noise sources, and to predict vehicle noise levels at various stages in vehicle development, first with estimates of noise sources, later with experimental data. In FY09, the physical mockup developed in FY08, with interior geometric shape similar to Orion CM (Crew Module) IML (Interior Mode Line), was used to validate SEA (Statistical Energy Analysis) acoustic model development with realistic ventilation fan sources. The sound power levels of these sources were unknown a priori, as opposed to previous studies that RSS (Reference Sound Source) with known sound power level was used. The modeling results were evaluated based on comparisons to measurements of sound pressure levels over a wide frequency range, including the frequency range where SEA gives good results. Sound intensity measurement was performed over a rectangular-shaped grid system enclosing the ventilation fan source. Sound intensities were measured at the top, front, back, right, and left surfaces of the and system. Sound intensity at the bottom surface was not measured, but sound blocking material was placed tinder the bottom surface to reflect most of the incident sound energy back to the remaining measured surfaces. Integrating measured sound intensities over measured surfaces renders estimated sound power of the source. The reverberation time T6o of the mockup interior had been modified to match reverberation levels of ISS US Lab interior for speech frequency bands, i.e., 0.5k, 1k, 2k, 4 kHz, by attaching appropriately sized Thinsulate sound absorption material to the interior wall of the mockup. Sound absorption of Thinsulate was modeled in three methods: Sabine equation with measured mockup interior reverberation time T60, layup model based on past impedance tube testing, and layup model plus air absorption correction. The evaluation/validation was

  17. Bacterial Motility Reveals Unknown Molecular Organization

    PubMed Central

    Duchesne, Ismaël; Rainville, Simon; Galstian, Tigran

    2015-01-01

    The water solubility of lyotropic liquid crystals (LCs) makes them very attractive to study the behavior of biological microorganisms in an environment where local symmetry is broken (as often encountered in nature). Several recent studies have shown a dramatic change in the behavior of flagellated bacteria when swimming in solutions of the lyotropic LC disodium cromoglycate (DSCG). In this study, the movements of Escherichia coli bacteria in DSCG-water solutions of different concentrations are observed to improve our understanding of this phenomenon. In addition, the viscosity of DSCG aqueous solutions is measured as a function of concentration at room temperature. We also experimentally identify a previously undescribed isotropic pretransition zone where bacteria start sticking to each other and to surfaces. Simple estimations show that the unbalanced osmotic pressure induced depletion force might be responsible for this sticking phenomenon. An estimate of the bacteria propulsive force and the DSCG aggregates length (versus concentration) are calculated from the measured viscosity of the medium. All these quantities are found to undergo a strong increase in the pretransition zone, starting at a threshold concentration of 6 ± 1 wt % DSCG that is well below the known isotropic-LC transition (∼10 wt %). This study also shines light on the motility of flagellated bacteria in realistic environments, and it opens new avenues for interesting applications such as the use of motile microorganisms to probe the physical properties of their host or smart bandages that could guide bacteria out of wounds. PMID:26588572

  18. 52. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    52. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print Co., Los Angeles, CA, Photographer, Date unknown DETAILS OF MAIN FLOOR ELEVATOR LOBBY - Richfield Oil Building, 555 South Flower Street, Los Angeles, Los Angeles County, CA

  19. 49. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    49. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print Co., Los Angeles, CA, Photographer, Date unknown SECTION THROUGH BUILDING, LOOKING EAST - Richfield Oil Building, 555 South Flower Street, Los Angeles, Los Angeles County, CA

  20. 50. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    50. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print Co., Los Angleles, CA, Photographer, Date unknown ENTRANCE AND TYPICAL BAY ON FLOWER STREET - Richfield Oil Building, 555 South Flower Street, Los Angeles, Los Angeles County, CA

  1. 44. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print Co., Los Angeles, CA, Photographer, Date unknown FIRST FLOOR PLAN - Richfield Oil Building, 555 South Flower Street, Los Angeles, Los Angeles County, CA

  2. 45. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print Co., Los Angeles, CA, Photographer, Date unknown SECOND FLOOR PLAN - Richfield Oil Building, 555 South Flower Street, Los Angeles, Los Angeles County, CA

  3. 48. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    48. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print Co., Los Angeles, CA., Photographer, Date unknown SECTION THROUGH BUILDING, LOOKING NORTH - Richfield Oil Building, 555 South Flower Street, Los Angeles, Los Angeles County, CA

  4. 51. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    51. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print Co., Los Angeles, CA, Photographer, Date unknown EXTERIOR, ELEVATION DETAILS - Richfield Oil Building, 555 South Flower Street, Los Angeles, Los Angeles County, CA

  5. 46. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    46. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print Co., Los Angeles, CA, Photographer, Date unknown NORTH ELEVATION - Richfield Oil Building, 555 South Flower Street, Los Angeles, Los Angeles County, CA

  6. 47. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print Co., Los Angleles, CA, Photographer, Date unknown WEST ELEVATION - Richfield Oil Building, 555 South Flower Street, Los Angeles, Los Angeles County, CA

  7. 53. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    53. Photocopy of drawing (Source unknown, 1928) Rapid Blue Print Co., Los Angeles, CA, Photographer, Date unknown DETAILS OF CORRIDORS ON SECOND - TWELFTH FLOORS - Richfield Oil Building, 555 South Flower Street, Los Angeles, Los Angeles County, CA

  8. 53. Retail Pockets, Looking West, date unknown Historic Photograph, Photogapher ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    53. Retail Pockets, Looking West, date unknown Historic Photograph, Photogapher Unknown; Collection of William Everett, Jr. (Wilkes-Barre, PA), photocopy by Joseph E.B. Elliot - Huber Coal Breaker, 101 South Main Street, Ashley, Luzerne County, PA

  9. 4. Photographic copy of photograph (date unknown, original print in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Photographic copy of photograph (date unknown, original print in the possession of the Wisconsin Veterans Museums). COTTAGES WITH DIRT ROAD IN FOREGROUND. LOCATION UNKNOWN. - Wisconsin Home for Veterans, King, Waupaca County, WI

  10. 5. Photographic copy of photograph (date unknown, original print in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Photographic copy of photograph (date unknown, original print in the possession of the Wisconsin Veterans Museums). SIX COTTAGES. VIEW UNKNOWN. - Wisconsin Home for Veterans, King, Waupaca County, WI

  11. 8. Photographic copy of photograph (date unknown, original print in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Photographic copy of photograph (date unknown, original print in the possession of the Wisconsin Veterans Museums). SEVEN COTTAGES. VIEW UNKNOWN. - Wisconsin Home for Veterans, King, Waupaca County, WI

  12. 1. Historic American Buildings Survey Photographer Unknown. Furnished by Mrs ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Historic American Buildings Survey Photographer Unknown. Furnished by Mrs Mecia, Tombstone, Arizona. Date Unknown GENERAL VIEW MAIN CHURCH (SOUTHEAST ELEVATION). - San Xavier del Bac Mission, Mission Road, Tucson, Pima County, AZ

  13. 19. Photocopy of measured drawing (source unknown) 6 March 1945, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. Photocopy of measured drawing (source unknown) 6 March 1945, delineator unknown PROPOSED ADAPTIVE REUSE AS CLEMSON COLLEGE FACULTY CLUB, SECOND FLOOR PLAN - Woodburn, Woodburn Road, U.S. Route 76 vicinity, Pendleton, Anderson County, SC

  14. 18. Photocopy of measured drawing (source unknown) 6 March 1945, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. Photocopy of measured drawing (source unknown) 6 March 1945, delineator unknown PROPOSED ADAPTIVE REUSE AS CLEMSON COLLEGE FACULTY CLUB, FIRST FLOOR PLAN - Woodburn, Woodburn Road, U.S. Route 76 vicinity, Pendleton, Anderson County, SC

  15. 17. Photocopy of measured drawing (source unknown) 6 March 1945, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. Photocopy of measured drawing (source unknown) 6 March 1945, delineator unknown PROPOSED ADAPTIVE REUSE AS CLEMSON COLLEGE FACULTY CLUB, BASEMENT PLAN - Woodburn, Woodburn Road, U.S. Route 76 vicinity, Pendleton, Anderson County, SC

  16. 20. Photocopy of measured drawing (source unknown) 6 March 1945, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Photocopy of measured drawing (source unknown) 6 March 1945, delineator unknown PROPOSED ADAPTIVE REUSE AS CLEMSON COLLEGE FACULTY CLUB, ATTIC PLAN - Woodburn, Woodburn Road, U.S. Route 76 vicinity, Pendleton, Anderson County, SC

  17. 21. Photocopy of maesured drawing (source unknown) 6 March 1945, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. Photocopy of maesured drawing (source unknown) 6 March 1945, delineator unknown PROPOSED ADAPTIVE REUSE AS CLEMSON COLLEGE FACULTY CLUB, SITE PLAN - Woodburn, Woodburn Road, U.S. Route 76 vicinity, Pendleton, Anderson County, SC

  18. Design of a DNA chip for detection of unknown genetically modified organisms (GMOs).

    PubMed

    Nesvold, Håvard; Kristoffersen, Anja Bråthen; Holst-Jensen, Arne; Berdal, Knut G

    2005-05-01

    Unknown genetically modified organisms (GMOs) have not undergone a risk evaluation, and hence might pose a danger to health and environment. There are, today, no methods for detecting unknown GMOs. In this paper we propose a novel method intended as a first step in an approach for detecting unknown genetically modified (GM) material in a single plant. A model is designed where biological and combinatorial reduction rules are applied to a set of DNA chip probes containing all possible sequences of uniform length n, creating probes capable of detecting unknown GMOs. The model is theoretically tested for Arabidopsis thaliana Columbia, and the probabilities for detecting inserts and receiving false positives are assessed for various parameters for this organism. From a theoretical standpoint, the model looks very promising but should be tested further in the laboratory. The model and algorithms will be available upon request to the corresponding author.

  19. Twelve previously unknown phage genera are ubiquitous in global oceans

    SciTech Connect

    Holmfeldt, Karin; Solonenko, Natalie; Shah, Manesh B

    Viruses are fundamental to ecosystems ranging from oceans to humans, yet our ability to study them is bottlenecked by the lack of ecologically relevant isolates, resulting in unknowns dominating culture-independent surveys. Here we present genomes from 31 phages infecting multiple strains of the aquatic bacterium Cellulophaga baltica (Bacteroidetes) to provide data for an underrepresented and environmentally abundant bacterial lineage. Comparative genomics delineated 12 phage groups that (i) each represent a new genus, and (ii) represent one novel and four wellknown viral families. This diversity contrasts the few well-studied marine phage systems, but parallels the diversity of phages infecting human-associated bacteria.more » Although all 12 Cellulophaga phages represent new genera, the podoviruses and icosahedral, nontailed ssDNA phages were exceptional, with genomes up to twice as large as those previously observed for each phage type. Structural novelty was also substantial, requiring experimental phage proteomics to identify 83% of the structural proteins. The presence of uncommon nucleotide metabolism genes in four genera likely underscores the importance of scavenging nutrient-rich molecules as previously seen for phages in marine environments. Metagenomic recruitment analyses suggest that these particular Cellulophaga phages are rare and may represent a first glimpse into the phage side of the rare biosphere. However, these analyses also revealed that these phage genera are widespread, occurring in 94% of 137 investigated metagenomes. Together, this diverse and novel collection of phages identifies a small but ubiquitous fraction of unknown marine viral diversity and provides numerous environmentally relevant phage host systems for experimental hypothesis testing.« less

  20. Twelve previously unknown phage genera are ubiquitous in global oceans.

    PubMed

    Holmfeldt, Karin; Solonenko, Natalie; Shah, Manesh; Corrier, Kristen; Riemann, Lasse; Verberkmoes, Nathan C; Sullivan, Matthew B

    2013-07-30

    Viruses are fundamental to ecosystems ranging from oceans to humans, yet our ability to study them is bottlenecked by the lack of ecologically relevant isolates, resulting in "unknowns" dominating culture-independent surveys. Here we present genomes from 31 phages infecting multiple strains of the aquatic bacterium Cellulophaga baltica (Bacteroidetes) to provide data for an underrepresented and environmentally abundant bacterial lineage. Comparative genomics delineated 12 phage groups that (i) each represent a new genus, and (ii) represent one novel and four well-known viral families. This diversity contrasts the few well-studied marine phage systems, but parallels the diversity of phages infecting human-associated bacteria. Although all 12 Cellulophaga phages represent new genera, the podoviruses and icosahedral, nontailed ssDNA phages were exceptional, with genomes up to twice as large as those previously observed for each phage type. Structural novelty was also substantial, requiring experimental phage proteomics to identify 83% of the structural proteins. The presence of uncommon nucleotide metabolism genes in four genera likely underscores the importance of scavenging nutrient-rich molecules as previously seen for phages in marine environments. Metagenomic recruitment analyses suggest that these particular Cellulophaga phages are rare and may represent a first glimpse into the phage side of the rare biosphere. However, these analyses also revealed that these phage genera are widespread, occurring in 94% of 137 investigated metagenomes. Together, this diverse and novel collection of phages identifies a small but ubiquitous fraction of unknown marine viral diversity and provides numerous environmentally relevant phage-host systems for experimental hypothesis testing.

  1. Nitrogen cycle in microbial mats: completely unknown?

    NASA Astrophysics Data System (ADS)

    Coban, O.; Bebout, B.

    2015-12-01

    Microbial mats are thought to have originated around 3.7 billion years ago, most likely in the areas around submarine hydrothermal vents, which supplied a source of energy in the form of reduced chemical species from the Earth's interior. Active hydrothermal vents are also believed to exist on Jupiter's moon Europa, Saturn's moon Enceladus, and on Mars, earlier in that planet's history. Microbial mats have been an important force in the maintenance of Earth's ecosystems and the first photosynthesis was also originated there. Microbial mats are believed to exhibit most, if not all, biogeochemical processes that exist in aquatic ecosystems, due to the presence of different physiological groups of microorganisms therein. While most microbially mediated biogeochemical transformations have been shown to occur within microbial mats, the nitrogen cycle in the microbial mats has received very little study in spite of the fact that nitrogen usually limits growth in marine environments. We will present the first results in the determination of a complete nitrogen budget for a photosynthetic microbial mat. Both in situ sources and sinks of nitrogen in photosynthetic microbial mats are being measured using stable isotope techniques. Our work has a particular focus on recently described, but poorly understood, processes, e.g., anammox and dissimilatory nitrate reduction, and an emphasis on understanding the role that nitrogen cycling may play in generating biogenic nitrogen isotopic signatures and biomarker molecules. Measurements of environmental controls on nitrogen cycling should offer insight into the nature of co-evolution of these microbial communities and their planets of origin. Identifying the spatial (microscale) as well as temporal (diel and seasonal) distribution of nitrogen transformations, e.g., rates of nitrification and denitrification, within mats, particularly with respect to the distribution of photosynthetically-produced oxygen, is anticipated. The results

  2. Population extinction under bursty reproduction in a time-modulated environment

    NASA Astrophysics Data System (ADS)

    Vilk, Ohad; Assaf, Michael

    2018-06-01

    In recent years nondemographic variability has been shown to greatly affect dynamics of stochastic populations. For example, nondemographic noise in the form of a bursty reproduction process with an a priori unknown burst size, or environmental variability in the form of time-varying reaction rates, have been separately found to dramatically impact the extinction risk of isolated populations. In this work we investigate the extinction risk of an isolated population under the combined influence of these two types of nondemographic variation. Using the so-called momentum-space Wentzel-Kramers-Brillouin (WKB) approach and accounting for the explicit time dependence in the reaction rates, we arrive at a set of time-dependent Hamilton equations. To this end, we evaluate the population's extinction risk by finding the instanton of the time-perturbed Hamiltonian numerically, whereas analytical expressions are presented in particular limits using various perturbation techniques. We focus on two classes of time-varying environments: periodically varying rates corresponding to seasonal effects and a sudden decrease in the birth rate corresponding to a catastrophe. All our theoretical results are tested against numerical Monte Carlo simulations with time-dependent rates and also against a numerical solution of the corresponding time-dependent Hamilton equations.

  3. Chronic kidney disease of unknown etiology in Sri Lanka

    PubMed Central

    2016-01-01

    Introduction In the last two decades, chronic kidney disease of unknown etiology (CKDu) has emerged as a significant contributor to the burden of chronic kidney disease (CKD) in rural Sri Lanka. It is characterized by the absence of identified causes for CKD. The prevalence of CKDu is 15.1–22.9% in some Sri Lankan districts, and previous research has found an association with farming occupations. Methods A systematic literature review in Pubmed, Embase, Scopus, and Lilacs databases identified 46 eligible peer-reviewed articles and one conference abstract. Results Geographical mapping indicates a relationship between CKDu and agricultural irrigation water sources. Health mapping studies, human biological studies, and environment-based studies have explored possible causative agents. Most studies focused on likely causative agents related to agricultural practices, geographical distribution based on the prevalence and incidence of CKDu, and contaminants identified in drinking water. Nonetheless, the link between agrochemicals or heavy metals and CKDu remains to be established. No definitive cause for CKDu has been identified. Discussion Evidence to date suggests that the disease is related to one or more environmental agents, however pinpointing a definite cause for CKDu is challenging. It is plausible that CKDu is multifactorial. No specific guidelines or recommendations exist for treatment of CKDu, and standard management protocols for CKD apply. Changes in agricultural practices, provision of safe drinking water, and occupational safety precautions are recommended by the World Health Organization. PMID:27399161

  4. Chronic kidney disease of unknown etiology in Sri Lanka.

    PubMed

    Rajapakse, Senaka; Shivanthan, Mitrakrishnan Chrishan; Selvarajah, Mathu

    2016-07-01

    In the last two decades, chronic kidney disease of unknown etiology (CKDu) has emerged as a significant contributor to the burden of chronic kidney disease (CKD) in rural Sri Lanka. It is characterized by the absence of identified causes for CKD. The prevalence of CKDu is 15.1-22.9% in some Sri Lankan districts, and previous research has found an association with farming occupations. A systematic literature review in Pubmed, Embase, Scopus, and Lilacs databases identified 46 eligible peer-reviewed articles and one conference abstract. Geographical mapping indicates a relationship between CKDu and agricultural irrigation water sources. Health mapping studies, human biological studies, and environment-based studies have explored possible causative agents. Most studies focused on likely causative agents related to agricultural practices, geographical distribution based on the prevalence and incidence of CKDu, and contaminants identified in drinking water. Nonetheless, the link between agrochemicals or heavy metals and CKDu remains to be established. No definitive cause for CKDu has been identified. Evidence to date suggests that the disease is related to one or more environmental agents, however pinpointing a definite cause for CKDu is challenging. It is plausible that CKDu is multifactorial. No specific guidelines or recommendations exist for treatment of CKDu, and standard management protocols for CKD apply. Changes in agricultural practices, provision of safe drinking water, and occupational safety precautions are recommended by the World Health Organization.

  5. Previously unknown class of metalorganic compounds revealed in meteorites

    PubMed Central

    Ruf, Alexander; Kanawati, Basem; Hertkorn, Norbert; Yin, Qing-Zhu; Moritz, Franco; Harir, Mourad; Lucio, Marianna; Michalke, Bernhard; Wimpenny, Joshua; Shilobreeva, Svetlana; Bronsky, Basil; Saraykin, Vladimir; Gabelica, Zelimir; Gougeon, Régis D.; Quirico, Eric; Ralew, Stefan; Jakubowski, Tomasz; Haack, Henning; Gonsior, Michael; Jenniskens, Peter; Hinman, Nancy W.; Schmitt-Kopplin, Philippe

    2017-01-01

    The rich diversity and complexity of organic matter found in meteorites is rapidly expanding our knowledge and understanding of extreme environments from which the early solar system emerged and evolved. Here, we report the discovery of a hitherto unknown chemical class, dihydroxymagnesium carboxylates [(OH)2MgO2CR]−, in meteoritic soluble organic matter. High collision energies, which are required for fragmentation, suggest substantial thermal stability of these Mg-metalorganics (CHOMg compounds). This was corroborated by their higher abundance in thermally processed meteorites. CHOMg compounds were found to be present in a set of 61 meteorites of diverse petrological classes. The appearance of this CHOMg chemical class extends the previously investigated, diverse set of CHNOS molecules. A connection between the evolution of organic compounds and minerals is made, as Mg released from minerals gets trapped into organic compounds. These CHOMg metalorganic compounds and their relation to thermal processing in meteorites might shed new light on our understanding of carbon speciation at a molecular level in meteorite parent bodies. PMID:28242686

  6. 27. photographer unknown 10 July 1938 SHIP LOCK DEDICATION CEREMONIES. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. photographer unknown 10 July 1938 SHIP LOCK DEDICATION CEREMONIES. - Bonneville Project, Navigation Lock No. 1, Oregon shore of Columbia River near first Powerhouse, Bonneville, Multnomah County, OR

  7. 61. photographer unknown undated FIRST CONCRETE BEING POURED IN DRAFT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    61. photographer unknown undated FIRST CONCRETE BEING POURED IN DRAFT TUBE FLOOR SLAB. - Bonneville Project, Powerhouse No.1, Spanning Bradford Slough, from Bradford Island, Bonneville, Multnomah County, OR

  8. Recovering an unknown source in a fractional diffusion problem

    NASA Astrophysics Data System (ADS)

    Rundell, William; Zhang, Zhidong

    2018-09-01

    A standard inverse problem is to determine a source which is supported in an unknown domain D from external boundary measurements. Here we consider the case of a time-independent situation where the source is equal to unity in an unknown subdomain D of a larger given domain Ω and the boundary of D has the star-like shape, i.e.

  9. Carcinoma of Unknown Primary—Health Professional Version

    Cancer.gov

    Carcinoma of unknown primary (CUP) is a rare disease in which malignant cells are found in the body but the site of the primary cancer is not known. Most CUPs are adenocarcinomas, or undifferentiated tumors. Find evidence-based information on the treatment for carcinoma of unknown primary.

  10. General Unknown Screening by Ion Trap LC/MS/MS

    DTIC Science & Technology

    2010-04-01

    Subtitle 5 . Report Date April 2010 General Unknown Screening by Ion Trap LC/MS/MS 6 . Performing Organization Code 7. Author(s) 8... 5 Table 1: Analytical Data for Each of the...359 Compounds in the LC/MS/MS Library . . . . . . . . . . . 6 1 General Unknown ScreeninG by ion Trap lc/MS/MS INTrOduCTION The Federal Aviation

  11. 37 CFR 260.7 - Unknown copyright owners.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2014-07-01 2014-07-01 false Unknown copyright owners. 260.7 Section 260.7 Patents, Trademarks, and Copyrights U.S. COPYRIGHT OFFICE, LIBRARY OF CONGRESS... SERVICES' DIGITAL TRANSMISSIONS OF SOUND RECORDINGS AND MAKING OF EPHEMERAL PHONORECORDS § 260.7 Unknown...

  12. 5 CFR 1651.16 - Missing and unknown beneficiaries.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Missing and unknown beneficiaries. 1651... § 1651.16 Missing and unknown beneficiaries. (a) Locate and identify beneficiaries. (1) The TSP record... one or more beneficiaries (and not all) appear to be missing, payment of part of the participant's...

  13. 5 CFR 1651.16 - Missing and unknown beneficiaries.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Missing and unknown beneficiaries. 1651... § 1651.16 Missing and unknown beneficiaries. (a) Locate and identify beneficiaries. (1) The TSP record... one or more beneficiaries (and not all) appear to be missing, payment of part of the participant's...

  14. 5 CFR 1651.16 - Missing and unknown beneficiaries.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Missing and unknown beneficiaries. 1651... § 1651.16 Missing and unknown beneficiaries. (a) Locate and identify beneficiaries. (1) The TSP record... one or more beneficiaries (and not all) appear to be missing, payment of part of the participant's...

  15. 5 CFR 1651.16 - Missing and unknown beneficiaries.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Missing and unknown beneficiaries. 1651... § 1651.16 Missing and unknown beneficiaries. (a) Locate and identify beneficiaries. (1) The TSP record... one or more beneficiaries (and not all) appear to be missing, payment of part of the participant's...

  16. 5 CFR 1651.16 - Missing and unknown beneficiaries.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Missing and unknown beneficiaries. 1651... § 1651.16 Missing and unknown beneficiaries. (a) Locate and identify beneficiaries. (1) The TSP record... one or more beneficiaries (and not all) appear to be missing, payment of part of the participant's...

  17. Students' Conscious Unknowns about Artefacts and Natural Objects

    ERIC Educational Resources Information Center

    Vaz-Rebelo, Piedade; Fernandes, Paula; Morgado, Julia; Monteiro, António; Otero, José

    2016-01-01

    This study attempts to characterise what 7th- and 12th-grade students believe they do not know about artefacts and natural objects, as well as the dependence of what is unknown on a knowledge of these objects. The students were asked to make explicit through questioning what they did not know about a sample of objects. The unknowns generated were…

  18. Bayesian methods for characterizing unknown parameters of material models

    DOE PAGES

    Emery, J. M.; Grigoriu, M. D.; Field Jr., R. V.

    2016-02-04

    A Bayesian framework is developed for characterizing the unknown parameters of probabilistic models for material properties. In this framework, the unknown parameters are viewed as random and described by their posterior distributions obtained from prior information and measurements of quantities of interest that are observable and depend on the unknown parameters. The proposed Bayesian method is applied to characterize an unknown spatial correlation of the conductivity field in the definition of a stochastic transport equation and to solve this equation by Monte Carlo simulation and stochastic reduced order models (SROMs). As a result, the Bayesian method is also employed tomore » characterize unknown parameters of material properties for laser welds from measurements of peak forces sustained by these welds.« less

  19. Bayesian methods for characterizing unknown parameters of material models

    SciTech Connect

    Emery, J. M.; Grigoriu, M. D.; Field Jr., R. V.

    A Bayesian framework is developed for characterizing the unknown parameters of probabilistic models for material properties. In this framework, the unknown parameters are viewed as random and described by their posterior distributions obtained from prior information and measurements of quantities of interest that are observable and depend on the unknown parameters. The proposed Bayesian method is applied to characterize an unknown spatial correlation of the conductivity field in the definition of a stochastic transport equation and to solve this equation by Monte Carlo simulation and stochastic reduced order models (SROMs). As a result, the Bayesian method is also employed tomore » characterize unknown parameters of material properties for laser welds from measurements of peak forces sustained by these welds.« less

  20. Robust Fault Detection for Switched Fuzzy Systems With Unknown Input.

    PubMed

    Han, Jian; Zhang, Huaguang; Wang, Yingchun; Sun, Xun

    2017-10-03

    This paper investigates the fault detection problem for a class of switched nonlinear systems in the T-S fuzzy framework. The unknown input is considered in the systems. A novel fault detection unknown input observer design method is proposed. Based on the proposed observer, the unknown input can be removed from the fault detection residual. The weighted H∞ performance level is considered to ensure the robustness. In addition, the weighted H₋ performance level is introduced, which can increase the sensibility of the proposed detection method. To verify the proposed scheme, a numerical simulation example and an electromechanical system simulation example are provided at the end of this paper.

  1. 2. Photocopy of photograph (from Reading Co. Archives) Photographer unknown ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Photocopy of photograph (from Reading Co. Archives) Photographer unknown ca. 1937 NORTHEAST FRONT AND SOUTHEAST SIDE - Philadelphia & Reading Railroad, Terminal Station, 1115-1141 Market Street, Philadelphia, Philadelphia County, PA

  2. 15. Photocopy of photograph (original in WACC), photographer unknown, c. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Photocopy of photograph (original in WACC), photographer unknown, c. 1917 BEN ERICKSON IN WWI UNIFORM STANDING IN FRONT OF SOUTH LIVING ROOM WINDOW (ADOBE WALLS) - Faraway Ranch, Willcox, Cochise County, AZ

  3. 19. Photocopy of photograph Photographer unknown, ca. 1895 GENERAL VIEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. Photocopy of photograph Photographer unknown, ca. 1895 GENERAL VIEW OF KEY WEST WITH FORT TAYLOR IN THE BACKGROUND LOOKING WEST SOUTHWEST - Fort Taylor, Whitehead Spit Vicinity, Key West, Monroe County, FL

  4. 34. photographer unknown September 1937 ROOSEVELT ARRIVING FOR DEDICATION OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. photographer unknown September 1937 ROOSEVELT ARRIVING FOR DEDICATION OF BONNEVILLE DAM. - Bonneville Project, Columbia River, 1 mile Northeast of Exit 40, off Interstate 84, Bonneville, Multnomah County, OR

  5. 71. photographer unknown 9 September 1935 DOWNSTREAM SIDE OF POWERHOUSE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    71. photographer unknown 9 September 1935 DOWNSTREAM SIDE OF POWERHOUSE SUBSTRUCTURE, SHOWING FISHWAY AND DRAFT TUBE OUTLETS. - Bonneville Project, Powerhouse No.1, Spanning Bradford Slough, from Bradford Island, Bonneville, Multnomah County, OR

  6. 81. photographer unknown 11 June 1937 WORKMEN ON TURBINE BLADES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    81. photographer unknown 11 June 1937 WORKMEN ON TURBINE BLADES BEFORE LOWERING INTO DRAFT TUBE LINER. - Bonneville Project, Powerhouse No.1, Spanning Bradford Slough, from Bradford Island, Bonneville, Multnomah County, OR

  7. 72. photographer unknown 22 November 1935 PLACING CONCRETE FORM FOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    72. photographer unknown 22 November 1935 PLACING CONCRETE FORM FOR STATION SERVICE DRAFT TUBES. - Bonneville Project, Powerhouse No.1, Spanning Bradford Slough, from Bradford Island, Bonneville, Multnomah County, OR

  8. 62. photographer unknown undated ERECTING FORMS, PLACING REINFORCING STEEL, AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    62. photographer unknown undated ERECTING FORMS, PLACING REINFORCING STEEL, AND CONCRETING DRAFT PIER OF POWERHOUSE. - Bonneville Project, Powerhouse No.1, Spanning Bradford Slough, from Bradford Island, Bonneville, Multnomah County, OR

  9. 73. photographer unknown 9 January 1936 TOP OF DRAFT TUBE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    73. photographer unknown 9 January 1936 TOP OF DRAFT TUBE LINER AND SPEED RING PIERS. - Bonneville Project, Powerhouse No.1, Spanning Bradford Slough, from Bradford Island, Bonneville, Multnomah County, OR

  10. 60. photographer unknown undated CONCRETE BEING POURED ON CENTER PORTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    60. photographer unknown undated CONCRETE BEING POURED ON CENTER PORTION OF DRAFT TUBE FLOOR SLAB. - Bonneville Project, Powerhouse No.1, Spanning Bradford Slough, from Bradford Island, Bonneville, Multnomah County, OR

  11. 38. Historic photograph, photographer unknown, c. 1944. VIEW SHOWING BURROS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. Historic photograph, photographer unknown, c. 1944. VIEW SHOWING BURROS (OR MULES) CROSSING BRIDGE, LOOKING NORTHEAST. - Verde River Sheep Bridge, Spanning Verde River (Tonto National Forest), Cave Creek, Maricopa County, AZ

  12. 43. Photocopy of photograph (Pentran file), photographer and date unknown ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    43. Photocopy of photograph (Pentran file), photographer and date unknown (circa 1960). VIEW WEST, EAST SIDE ADMINISTRATION BUILDING - Newport News & Old Point Railway & Electric Company, Trolley Barn & Administration Building, 3400 Victoria Boulevard, Hampton, Hampton, VA

  13. 41. Photocopy of photograph (Pentran file), photographer and date unknown. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. Photocopy of photograph (Pentran file), photographer and date unknown. Shows trolley with Trolley Barn and Administration Building in background. VIEW NORTHEAST - Newport News & Old Point Railway & Electric Company, Trolley Barn & Administration Building, 3400 Victoria Boulevard, Hampton, Hampton, VA

  14. 25. Photocopy of photograph (Source unknown, c. 19231925) EXTERIOR, CLOSEUP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. Photocopy of photograph (Source unknown, c. 1923-1925) EXTERIOR, CLOSE-UP OF SOUTH FRONT OF MISSION AFTER RESTORATION, C. 1923-1925 - Mission San Francisco Solano de Sonoma, First & Spain Streets, Sonoma, Sonoma County, CA

  15. 43. Photographer unknown September 1967 VISITOR INFORMATION KIOSK, LOCATED NEAR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    43. Photographer unknown September 1967 VISITOR INFORMATION KIOSK, LOCATED NEAR THE POWDER MILL ROAD INTERCHANGE. (NPS/NCR (cn) 9995-C) - Baltimore-Washington Parkway, Greenbelt, Prince George's County, MD

  16. Carcinoma of Unknown Primary Treatment (PDQ®)—Patient Version

    Cancer.gov

    Carcinoma of unknown primary (CUP), treatment can include surgery, radiation therapy, chemotherapy, or hormone therapy. Get detailed information about the diagnosis and treatment of CUP in this expert-reviewed summary.

  17. 43. Photocopy of photograph, photographer unknown, ca January 1929 (original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    43. Photocopy of photograph, photographer unknown, ca January 1929 (original print located at Arizona Department of Transportation, Phoenix AZ). COMPLETED BRIDGE. - Navajo Bridge, Spanning Colorado River at U.S. Highway 89 Alternate, Page, Coconino County, AZ

  18. 35. Photocopy of drawing (from Library of Congress) Artist unknown ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. Photocopy of drawing (from Library of Congress) Artist unknown 1891 SOUTH FRONT FROM THE SOUTHWEST - Patent Office Building, Bounded by Seventh, Ninth, F & G Streets, Northwest, Washington, District of Columbia, DC

  19. 356. Delineator Unknown March 1946 STATE OF CALIFORNIA; DEPARTMENT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    356. Delineator Unknown March 1946 STATE OF CALIFORNIA; DEPARTMENT OF PUBLIC WORKS; SAN FRANCISCO - OAKLAND BAY BRIDGE; GENERAL DATA; PLAT III - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  20. 41. Upstream end of emergency spillway excavation. Photographer unknown, 1929. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. Upstream end of emergency spillway excavation. Photographer unknown, 1929. Source: Arizona Department of Water Resources (ADWR). - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  1. 44. Reinforcement construction to Pleasant Dam. Photographer unknown, 1935. Source: ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. Reinforcement construction to Pleasant Dam. Photographer unknown, 1935. Source: Huber Collection, University of California, Berkeley, Water Resources Library. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  2. 4. VIEW OF BORING MILL IN OPERATION, operator unknown (note ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW OF BORING MILL IN OPERATION, operator unknown (note console in background). - Juniata Shops, Erecting Shop & Machine Shop, East of Fourth Avenue, between Fourth & Fifth Streets, Altoona, Blair County, PA

  3. 3. VIEW OF BORING MILL IN OPERATION, operator unknown (note ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW OF BORING MILL IN OPERATION, operator unknown (note console in background). - Juniata Shops, Erecting Shop & Machine Shop, East of Fourth Avenue, between Fourth & Fifth Streets, Altoona, Blair County, PA

  4. 6. Photographic copy of photograph (date unknown, original print in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Photographic copy of photograph (date unknown, original print in the possession of the Wisconsin Veterans Museums). COTTAGES, INCLUDING 'J.P. McPHERSON POST NO. 27 CAFE GENEVA'. - Wisconsin Home for Veterans, King, Waupaca County, WI

  5. 7. Photographic copy of photograph (date unknown, original print in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Photographic copy of photograph (date unknown, original print in the possession of the Wisconsin Veterans Museums). LAKE IN FOREGROUND, COTTAGES IN BACK. - Wisconsin Home for Veterans, King, Waupaca County, WI

  6. 12. Photocopy of lithograph (source unknown) The Armor Lithograph Company, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Photocopy of lithograph (source unknown) The Armor Lithograph Company, Ltd., Pittsburgh, Pennsylvania, ca. 1888 COURTHOUSE AND JAIL, FROM THE WEST - Allegheny County Courthouse & Jail, 436 Grant Street (Courthouse), 420 Ross Street (Jail), Pittsburgh, Allegheny County, PA

  7. 6. FORSYTHIA WALK AFTER WIDENING Photocopy of photograph, date unknown ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. FORSYTHIA WALK AFTER WIDENING Photocopy of photograph, date unknown National Park Service, National Capital Region files - Dumbarton Oaks Park, Thirty-second & R Streets Northwest, Washington, District of Columbia, DC

  8. 48. Photographer unknown February 1925 MENDOCINO COUNTY, SECTION K, HIGHWAY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    48. Photographer unknown February 1925 MENDOCINO COUNTY, SECTION K, HIGHWAY 1. 1-MEN-1-K #39, LOG GUARD RAIL, 2-25. - Redwood National & State Parks Roads, California coast from Crescent City to Trinidad, Crescent City, Del Norte County, CA

  9. 80. photographer unknown 7 June 1937 PLACING MAIN THRUST BEARING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    80. photographer unknown 7 June 1937 PLACING MAIN THRUST BEARING ASSEMBLY IN UNIT NO 2. - Bonneville Project, Powerhouse No.1, Spanning Bradford Slough, from Bradford Island, Bonneville, Multnomah County, OR

  10. Method for identifying known materials within a mixture of unknowns

    DOEpatents

    Wagner, John S.

    2000-01-01

    One or both of two methods and systems are used to determine concentration of a known material in an unknown mixture on the basis of the measured interaction of electromagnetic waves upon the mixture. One technique is to utilize a multivariate analysis patch technique to develop a library of optimized patches of spectral signatures of known materials containing only those pixels most descriptive of the known materials by an evolutionary algorithm. Identity and concentration of the known materials within the unknown mixture is then determined by minimizing the residuals between the measurements from the library of optimized patches and the measurements from the same pixels from the unknown mixture. Another technique is to train a neural network by the genetic algorithm to determine the identity and concentration of known materials in the unknown mixture. The two techniques may be combined into an expert system providing cross checks for accuracy.

  11. System for identifying known materials within a mixture of unknowns

    DOEpatents

    Wagner, John S.

    1999-01-01

    One or both of two methods and systems are used to determine concentration of a known material in an unknown mixture on the basis of the measured interaction of electromagnetic waves upon the mixture. One technique is to utilize a multivariate analysis patch technique to develop a library of optimized patches of spectral signatures of known materials containing only those pixels most descriptive of the known materials by an evolutionary algorithm. Identity and concentration of the known materials within the unknown mixture is then determined by minimizing the residuals between the measurements from the library of optimized patches and the measurements from the same pixels from the unknown mixture. Another technique is to train a neural network by the genetic algorithm to determine the identity and concentration of known materials in the unknown mixture. The two techniques may be combined into an expert system providing cross checks for accuracy.

  12. 47. Photocopy of postcard (Pentran file), photographer unknown. Hampton's Old ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. Photocopy of postcard (Pentran file), photographer unknown. Hampton's Old Point Comfort electric trolley in 1921. - Newport News & Old Point Railway & Electric Company, Trolley Barn & Administration Building, 3400 Victoria Boulevard, Hampton, Hampton, VA

  13. 3. Photocopy of photograph (location of original unknown) Mary Mather, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Photocopy of photograph (location of original unknown) Mary Mather, photographer, ca. 1920 PARTIAL EAST ELEVATION, OBSCURED BY FOLIAGE - Bagatelle Plantation, East River Road (moved to Iberville Parish), Donaldsonville, Ascension Parish, LA

  14. 2. Photocopy of photograph (location of original unknown) Mary Mather, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Photocopy of photograph (location of original unknown) Mary Mather, photographer, ca. 1920 GENERAL VIEW OF WEST (LEFT) AND SOUTH (RIGHT) FACADES, TAKEN FROM LEVEE - Bagatelle Plantation, East River Road (moved to Iberville Parish), Donaldsonville, Ascension Parish, LA

  15. Genetics Experts Unite to I.D. Unknown Katrina Victims

    MedlinePlus

    ... News From NIH Genetics Experts Unite to I.D. Unknown Katrina Victims Past Issues / Summer 2006 Table ... and genetics," says team member Stephen Sherry, Ph.D., of NLM's National Center for Biotechnology Information, "is ...

  16. 11. Photocopy of photograph (from St. Paul's Church) Photographer unknown ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Photocopy of photograph (from St. Paul's Church) Photographer unknown 1886 'EPISCOPAL CHURCH, CORNER OF 1ST AND J ST. BENICIA' WEST AND SOUTH SIDES - St. Paul's Episcopal Church, 120 East J Street, Benicia, Solano County, CA

  17. 51. BOILER ROOM. SMALL BOILER ON LEFT OF UNKNOWN MANUFACTURE, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    51. BOILER ROOM. SMALL BOILER ON LEFT OF UNKNOWN MANUFACTURE, WITH INDUCTION MOTORS. HARTLEY BOILER, MONTGOMERY, ALABAMA, ON RIGHT. - Prattville Manufacturing Company, Number One, 242 South Court Street, Prattville, Autauga County, AL

  18. View of an unknown industrial building in the Dolphin Jute ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of an unknown industrial building in the Dolphin Jute Mill Complex, looking southwest. Note Garret Mountain at upper left and historic Dexter-Lambert smokestack. - Dolphin Manufacturing Company, Spruce & Barbour Streets, Paterson, Passaic County, NJ

  19. 22. Photographer unknown, 1956 AERIAL VIEW, LOOKING SOUTHSOUTHEAST, BUILDING 20 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. Photographer unknown, 1956 AERIAL VIEW, LOOKING SOUTH-SOUTHEAST, BUILDING 20 AT LEFT. DARK AREAS ARE LANDSCAPED. - U. S. Veterans Administration Medical Center, 2100 Ridgecrest Southeast, Albuquerque, Bernalillo County, NM

  20. System for identifying known materials within a mixture of unknowns

    DOEpatents

    Wagner, J.S.

    1999-07-20

    One or both of two methods and systems are used to determine concentration of a known material in an unknown mixture on the basis of the measured interaction of electromagnetic waves upon the mixture. One technique is to utilize a multivariate analysis patch technique to develop a library of optimized patches of spectral signatures of known materials containing only those pixels most descriptive of the known materials by an evolutionary algorithm. Identity and concentration of the known materials within the unknown mixture is then determined by minimizing the residuals between the measurements from the library of optimized patches and the measurements from the same pixels from the unknown mixture. Another technique is to train a neural network by the genetic algorithm to determine the identity and concentration of known materials in the unknown mixture. The two techniques may be combined into an expert system providing cross checks for accuracy. 37 figs.

  1. 47. Photocopy of plans. Draftsman unknown, 1916 ADDITION TO CAR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. Photocopy of plans. Draftsman unknown, 1916 ADDITION TO CAR BARN. LONGITUDINAL AND CROSS SECTIONS. VIEWS TO SOUTH AND WEST. - Milwaukee Light, Heat & Traction Company, 8336 West Lapham Street, West Allis, Milwaukee County, WI

  2. 8. VIEW SHOWING THE DEMOSSING OF GRAND CANAL LOCATION UNKNOWN. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW SHOWING THE DEMOSSING OF GRAND CANAL LOCATION UNKNOWN. AT TEAM OF HORSES ON OPPOSITE BANKS OF THE CANAL DRAG A CHAIN BETWEEN THEM ALONG THE BOTTOM OF THE CANAL, WHICH PULLS THE MOSS AND WEEDS LOOSE. THE PLANS THEN FLOAT DOWN THE CANAL AND ARE CAUGHT IN A SCREEN AND REMOVED. Photographer unknown, 1923 - Grand Canal, North side of Salt River, Tempe, Maricopa County, AZ

  3. Pregnancy of unknown location: Outcome in a tertiary care hospital.

    PubMed

    Amer, Nuzhat; Amer, Muhammad; Kolkaila, Mohamed Abdoh; Yaqoob, Shahida

    2015-10-01

    To find out the outcome of a cohort of women with pregnancy of unknown location presenting to a tertiary care hospital. The prospective study was conducted from January to December, 2011, at Early Pregnancy Assessment Unit, King Faisal Military Hospital, Khamis Mushait, Saudi Arabia. Data was collected for women with early pregnancy or with history of amenorrhoea, bleeding or pain. These women were investigated with serum beta-human chorionic gonadotrophin levels twice weekly and transvaginal ultrasonography weekly. Expectant management was done for failing pregnancy of unknown location while medical or surgical management was considered for persistent pregnancy of unknown location and ectopic pregnancy. During study period, 7215 patients were admitted, and, of them, 2212(30.6%) were patients with early pregnancy. Meeting the inclusion criteria were 183(2.53%) patients who formed the study sample. There were 131(71.6%) patients presenting with amenorrhoea, 90(49.2%) had bleeding and 93(50.8%) presented with pain. Outcome of 100(54.6%) patients was failing pregnancy of unknown location, 58(31.7%) had intrauterine pregnancy, 14(7.7%) converted to ectopic pregnancy, while 11(6%) had persistent pregnancy of unknown location. All patients with persistent pregnancy of unknown location and 5(36%) patients with ectopic pregnancy were medically treated. Five (36%) patients having ectopic pregnancy were managed surgically. Management of choice for asymptomatic patients having pregnancy of unknown location is expectant management. Most of the patients suspected to have Most of the patients with persistent pregnancy of unknown location and ectopic pregnancy can be managed medically.

  4. Laboratory environmental factors and pain behavior: the relevance of unknown unknowns to reproducibility and translation.

    PubMed

    Mogil, Jeffrey S

    2017-03-22

    The poor record of basic-to-clinical translation in recent decades has led to speculation that preclinical research is "irreproducible", and this irreproducibility in turn has largely been attributed to deficiencies in reporting and statistical practices. There are, however, a number of other reasonable explanations of both poor translation and difficulties in one laboratory replicating the results of another. This article examines these explanations as they pertain to preclinical pain research. I submit that many instances of apparent irreproducibility are actually attributable to interactions between the phenomena and interventions under study and "latent" environmental factors affecting the rodent subjects. These environmental variables-often causing stress, and related to both animal husbandry and the specific testing context-differ greatly between labs, and continue to be identified, suggesting that our knowledge of their existence is far from complete. In pain research in particular, laboratory stressors can produce great variability of unpredictable direction, as stress is known to produce increases (stress-induced hyperalgesia) or decreases (stress-induced analgesia) in pain depending on its parameters. Much greater attention needs to be paid to the study of the laboratory environment if replication and translation are to be improved.

  5. LC-MS/MS screening strategy for unknown adducts to N-terminal valine in hemoglobin applied to smokers and nonsmokers.

    PubMed

    Carlsson, Henrik; von Stedingk, Hans; Nilsson, Ulrika; Törnqvist, Margareta

    2014-12-15

    Electrophilically reactive compounds have the ability to form adducts with nucleophilic sites in DNA and proteins, constituting a risk for toxic effects. Mass spectrometric detection of adducts to N-terminal valine in hemoglobin (Hb) after detachment by modified Edman degradation procedures is one approach for in vivo monitoring of exposure to electrophilic compounds/metabolites. So far, applications have been limited to one or a few selected reactive species, such as acrylamide and its metabolite glycidamide. This article presents a novel screening strategy for unknown Hb adducts to be used as a basis for an adductomic approach. The method is based on a modified Edman procedure, FIRE, specifically developed for LC-MS/MS analysis of N-terminal valine adducts in Hb detached as fluorescein thiohydantoin (FTH) derivatives. The aim is to detect and identify a priori unknown Hb adducts in human blood samples. Screening of valine adducts was performed by stepwise scanning of precursor ions in small mass increments, monitoring four fragments common for the FTH derivative of valine with different N-substitutions in the multiple-reaction mode, covering a mass range of 135 Da (m/z 503-638). Samples from six smokers and six nonsmokers were analyzed. Control experiments were performed to compare these results with known adducts and to check for artifactual formation of adducts. In all samples of smokers and nonsmokers, seven adducts were identified, of which six have previously been studied. Nineteen unknown adducts were observed, and 14 of those exhibited fragmentation patterns similar to earlier studied FTH derivatives of adducts to valine. Identification of the unknown adducts will be the focus of future work. The presented methodology is a promising screening tool using Hb adducts to indicate exposure to potentially toxic electrophilic compounds and metabolites.

  6. MoCha: Molecular Characterization of Unknown Pathways.

    PubMed

    Lobo, Daniel; Hammelman, Jennifer; Levin, Michael

    2016-04-01

    Automated methods for the reverse-engineering of complex regulatory networks are paving the way for the inference of mechanistic comprehensive models directly from experimental data. These novel methods can infer not only the relations and parameters of the known molecules defined in their input datasets, but also unknown components and pathways identified as necessary by the automated algorithms. Identifying the molecular nature of these unknown components is a crucial step for making testable predictions and experimentally validating the models, yet no specific and efficient tools exist to aid in this process. To this end, we present here MoCha (Molecular Characterization), a tool optimized for the search of unknown proteins and their pathways from a given set of known interacting proteins. MoCha uses the comprehensive dataset of protein-protein interactions provided by the STRING database, which currently includes more than a billion interactions from over 2,000 organisms. MoCha is highly optimized, performing typical searches within seconds. We demonstrate the use of MoCha with the characterization of unknown components from reverse-engineered models from the literature. MoCha is useful for working on network models by hand or as a downstream step of a model inference engine workflow and represents a valuable and efficient tool for the characterization of unknown pathways using known data from thousands of organisms. MoCha and its source code are freely available online under the GPLv3 license.

  7. Erythropoietin Levels in Elderly Patients with Anemia of Unknown Etiology

    PubMed Central

    Sriram, Swetha; Martin, Alison; Xenocostas, Anargyros; Lazo-Langner, Alejandro

    2016-01-01

    Background In many elderly patients with anemia, a specific cause cannot be identified. This study investigates whether erythropoietin levels are inappropriately low in these cases of “anemia of unknown etiology” and whether this trend persists after accounting for confounders. Methods This study includes all anemic patients over 60 years old who had erythropoietin measured between 2005 and 2013 at a single center. Three independent reviewers used defined criteria to assign each patient’s anemia to one of ten etiologies: chronic kidney disease, iron deficiency, chronic disease, confirmed myelodysplastic syndrome (MDS), suspected MDS, vitamin B12 deficiency, folate deficiency, anemia of unknown etiology, other etiology, or multifactorial etiology. Iron deficiency anemia served as the comparison group in all analyses. We used linear regression to model the relationship between erythropoietin and the presence of each etiology, sequentially adding terms to the model to account for the hemoglobin concentration, estimated glomerular filtration rate (eGFR) and Charlson Comorbidity Index. Results A total of 570 patients met the inclusion criteria. Linear regression analysis showed that erythropoietin levels in chronic kidney disease, anemia of chronic disease and anemia of unknown etiology were lower by 48%, 46% and 27%, respectively, compared to iron deficiency anemia even after adjusting for hemoglobin, eGFR and comorbidities. Conclusions We have shown that erythropoietin levels are inappropriately low in anemia of unknown etiology, even after adjusting for confounders. This suggests that decreased erythropoietin production may play a key role in the pathogenesis of anemia of unknown etiology. PMID:27310832

  8. A novel algorithm for fast grasping of unknown objects using C-shape configuration

    NASA Astrophysics Data System (ADS)

    Lei, Qujiang; Chen, Guangming; Meijer, Jonathan; Wisse, Martijn

    2018-02-01

    Increasing grasping efficiency is very important for the robots to grasp unknown objects especially subjected to unfamiliar environments. To achieve this, a new algorithm is proposed based on the C-shape configuration. Specifically, the geometric model of the used under-actuated gripper is approximated as a C-shape. To obtain an appropriate graspable position, this C-shape configuration is applied to fit geometric model of an unknown object. The geometric model of unknown object is constructed by using a single-view partial point cloud. To examine the algorithm using simulations, a comparison of the commonly used motion planners is made. The motion planner with the highest number of solved runs, lowest computing time and the shortest path length is chosen to execute grasps found by this grasping algorithm. The simulation results demonstrate that excellent grasping efficiency is achieved by adopting our algorithm. To validate this algorithm, experiment tests are carried out using a UR5 robot arm and an under-actuated gripper. The experimental results show that steady grasping actions are obtained. Hence, this research provides a novel algorithm for fast grasping of unknown objects.

  9. Quantum key distribution with an unknown and untrusted source

    NASA Astrophysics Data System (ADS)

    Zhao, Yi; Qi, Bing; Lo, Hoi-Kwong

    2008-05-01

    The security of a standard bidirectional “plug-and-play” quantum key distribution (QKD) system has been an open question for a long time. This is mainly because its source is equivalently controlled by an eavesdropper, which means the source is unknown and untrusted. Qualitative discussion on this subject has been made previously. In this paper, we solve this question directly by presenting the quantitative security analysis on a general class of QKD protocols whose sources are unknown and untrusted. The securities of standard Bennett-Brassard 1984 protocol, weak+vacuum decoy state protocol, and one-decoy state protocol, with unknown and untrusted sources are rigorously proved. We derive rigorous lower bounds to the secure key generation rates of the above three protocols. Our numerical simulation results show that QKD with an untrusted source gives a key generation rate that is close to that with a trusted source.

  10. Molecular toolbox for the identification of unknown genetically modified organisms.

    PubMed

    Ruttink, Tom; Demeyer, Rolinde; Van Gulck, Elke; Van Droogenbroeck, Bart; Querci, Maddalena; Taverniers, Isabel; De Loose, Marc

    2010-03-01

    Competent laboratories monitor genetically modified organisms (GMOs) and products derived thereof in the food and feed chain in the framework of labeling and traceability legislation. In addition, screening is performed to detect the unauthorized presence of GMOs including asynchronously authorized GMOs or GMOs that are not officially registered for commercialization (unknown GMOs). Currently, unauthorized or unknown events are detected by screening blind samples for commonly used transgenic elements, such as p35S or t-nos. If (1) positive detection of such screening elements shows the presence of transgenic material and (2) all known GMOs are tested by event-specific methods but are not detected, then the presence of an unknown GMO is inferred. However, such evidence is indirect because it is based on negative observations and inconclusive because the procedure does not identify the causative event per se. In addition, detection of unknown events is hampered in products that also contain known authorized events. Here, we outline alternative approaches for analytical detection and GMO identification and develop new methods to complement the existing routine screening procedure. We developed a fluorescent anchor-polymerase chain reaction (PCR) method for the identification of the sequences flanking the p35S and t-nos screening elements. Thus, anchor-PCR fingerprinting allows the detection of unique discriminative signals per event. In addition, we established a collection of in silico calculated fingerprints of known events to support interpretation of experimentally generated anchor-PCR GM fingerprints of blind samples. Here, we first describe the molecular characterization of a novel GMO, which expresses recombinant human intrinsic factor in Arabidopsis thaliana. Next, we purposefully treated the novel GMO as a blind sample to simulate how the new methods lead to the molecular identification of a novel unknown event without prior knowledge of its transgene

  11. A-Priori Tuning of Modified Magnussen Combustion Model

    NASA Technical Reports Server (NTRS)

    Norris, A. T.

    2016-01-01

    In the application of CFD to turbulent reacting flows, one of the main limitations to predictive accuracy is the chemistry model. Using a full or skeletal kinetics model may provide good predictive ability, however, at considerable computational cost. Adding the ability to account for the interaction between turbulence and chemistry improves the overall fidelity of a simulation but adds to this cost. An alternative is the use of simple models, such as the Magnussen model, which has negligible computational overhead, but lacks general predictive ability except for cases that can be tuned to the flow being solved. In this paper, a technique will be described that allows the tuning of the Magnussen model for an arbitrary fuel and flow geometry without the need to have experimental data for that particular case. The tuning is based on comparing the results of the Magnussen model and full finite-rate chemistry when applied to perfectly and partially stirred reactor simulations. In addition, a modification to the Magnussen model is proposed that allows the upper kinetic limit for the reaction rate to be set, giving better physical agreement with full kinetic mechanisms. This procedure allows a simple reacting model to be used in a predictive manner, and affords significant savings in computational costs for simulations.

  12. Influence of multiple categories on the prediction of unknown properties

    PubMed Central

    Verde, Michael F.; Murphy, Gregory L.; Ross, Brian H.

    2006-01-01

    Knowing an item's category helps us predict its unknown properties. Previous studies suggest that when asked to evaluate the probability of an unknown property, people tend to consider only an item's most likely category, ignoring alternative categories. In the present study, property prediction took the form of either a probability rating or a speeded, binary-choice judgment. Consistent with past findings, subjects ignored alternative categories in their probability ratings. However, their binary-choice judgments were influenced by alternative categories. This novel finding suggests that the way category knowledge is used in prediction depends critically on the form of the prediction. PMID:16156183

  13. Adaptive Incentive Controls for Stackelberg Games with Unknown Cost Functionals.

    DTIC Science & Technology

    1984-01-01

    APR EZT:: F I AN 73S e OsL:-: UNCLASSI?:-- Q4~.’~- .A.., 6, *~*i i~~*~~*.- U ADAPTIVE INCENTIVE CONTROLS FOR STACKELBERG GAMES WITH UNKNOWN COST...AD-A161 885 ADAPTIVE INCENTIVE CONTROLS FOR STACKELBERG GAMES WITH i/1 UNKNOWN COST FUNCTIONALSCU) ILLINOIS UNIV AT URBANA DECISION AND CONTROL LAB T...ORGANIZATION 6b. OFFICE SYMBOL 7.. NAME OF MONITORING ORGANIZATION CoriaeLcenef~pda~ Joint Services Electronics Program Laboratory, Univ. of Illinois N/A

  14. 17. Photographic copy of photograph. Location unknown but assumed to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. Photographic copy of photograph. Location unknown but assumed to be uper end of canal. Features no longer extant. (Source: U.S. Department of Interior. Office of Indian Affairs. Indian Irrigation service. Annual Report, Fiscal Year 1925. Vol. I, Narrative and Photographs, Irrigation District #4, California and Southern Arizona, RG 75, Entry 655, Box 28, National Archives, Washington, DC.) Photographer unknown. MAIN (TITLED FLORENCE) CANAL, WASTEWAY, SLUICEWAY, & BRIDGE, 1/26/25. - San Carlos Irrigation Project, Marin Canal, Amhurst-Hayden Dam to Picacho Reservoir, Coolidge, Pinal County, AZ

  15. A Nonlinear Model Predictive Control Algorithm for Obstacle Avoidance in Autonomous Ground Vehicles within Unknown Environments

    DTIC Science & Technology

    2015-04-24

    xs , ys , xe , ye ) double EndPo in t s [L...Distribution Statement A. Approved for public release. #26161 350 400 450 100 150 200 250 300 350 400 450 500 550 600 x (m) y (m ) Start Target U0 = 10...longitudinal speed 350 400 450 100 150 200 250 300 350 400 450 500 550 600 x (m) y (m ) Start Target (a) Trajectory 0 5 10 15 0 1 t (s) f ( U0 = 30

  16. Learning of Unknown Environments in Goal-Directed Guidance and Navigation Tasks: Autonomous Systems and Humans

    NASA Astrophysics Data System (ADS)

    Vidal, Joao Vasco Silvestres

    Este trabalho expoe um estudo teorico e experimental das propriedades anisotropicas magnetoeletricas (ME) em diferentes compositos contendo monocristais piezoeletricos (PE), maioritariamente sem chumbo na sua composicao, com vista a diversas aplicacoes multifuncionais. Uma descricao linear do efeito ME em termos de campos eletricos, magneticos e elasticos e constantes materiais e apresentada. Um modelo fenomenologico quasi-estatico e usado para ilustrar a relacao entre as constantes materiais, sua anisotropia e os coeficientes MEs transversais de tensao e carga. Subsequentemente, este modelo e empregue para estimar o maximo coeficiente ME direto de tensao expectavel numa serie de compositos tri-camadas de Metglas/Piezocristal/Metglas em funcao da orientacao do cristal PE. Demonstra-se assim como os efeitos MEs sao fortemente dependentes da orientacao cristalina, o que suporta a possibilidade de se gerarem coeficientes MEs de tensao elevados em compositos contendo monocristais PEs sem chumbo como o niobato de litio (LiNbO3; LNO), tantalato de litio (LiTaO3), ortofosfato de galio (GaPO4; GPO), quartzo (SiO2), langatato (La3Ga5.5Ta0.5O14) e langasite (La3Ga5SiO14) atraves da otimizacao da orientacao cristalina. Uma tecnica experimental dinâmica de lock-in para a medicao da impedância e efeito ME direto e exposta. O formalismo descritivo desta tecnica, assim como um arranjo experimental desenvolvido para o efeito sao apresentados. O esquema e caracteristicas deste, assim como diferentes formas de reduzir o ruido e a indesejavel inducao mutua sao exploradas. Um estudo comparativo do efeito ME direto em compositos tri-camadas de Metglas e monocristais de LNO e PMN-PT conectados de forma simples e exposto. Embora o PMN-PT possua piezocoeficientes de carga muito superiores aos do LNO, o coeficiente ME direto de tensao demonstrou-se comparavel entre ambos os compositos devido a uma muito menor permitividade dieletrica do LNO. Calculos teoricos indicam ainda que as propriedades MEs poderao ser significativamente melhoradas (ate 500 V/(cm.Oe)) atraves da otimizacao do ângulo de corte do LNO, espessura relativa entre camadas ferroeletrica/ferromagnetica e uma melhor colagem entre o Metglas e o LNO. Vantagens da utilizacao do material ferroeletrico LNO em compositos MEs sao discutidas. Num estudo subsequente, as propriedades dinâmicas anisotropicas de impedância e MEs em compositos tri-camadas de Metglas e monocristais PEs sem chumbo de LNO e GPO sao exploradas. Medicoes foram realizadas em funcao do corte de cristal, magnitude e orientacao do campo magnetico de polarizacao e frequencia do campo de modulacao. Coeficientes MEs altamente intensos em certos modos de ressonância sao explorados, e a sua relacao com as propriedades materiais dos cristais e geometria dos compositos e investigada. Um coeficiente ME de ate 249 V/(cm.Oe) foi aqui observado num composito com um cristal de LNO com corte 41ºY a 323.1 kHz. Mostramos assim que compositos multicamadas contendo cristais sem chumbo de LNO e GPO podem exibir efeitos MEs anisotropicos relativamente elevados. Demonstramos tambem que o controlo da orientacao dos cristais PEs pode em principio ser usado na obtencao de propriedades MEs anisotropicas desejaveis para qualquer aplicacao. Caracteristicas unicas como elevada estabilidade quimica, piezoeletricidade linear e robusteza termica abrem verdadeiras perspetivas para a utilizacao de compositos baseados no LNO e GPO em diversas aplicacoes. Eventualmente, compositos bi-camadas contendo lâminas PEs com bidominios de LNO com corte 127ºY foram estudados tanto teoricamente como experimentalmente. Estas lâminas de LNO possuem uma estrutura de bidominios com vetores de polarizacao espontânea opostos ao longo da direcao da sua espessura (i.e. uma estrutura de macrodominios ferroeletricos "head-to-head" ou "tail-to-tail") Medicoes de impedância, efeito ME e densidade de ruido magnetico equivalente foram realizadas nos compositos operando sob condicoes quasi-estaticas e de ressonância. Coeficientes MEs de ate 578 V/(cm.Oe) foram obtidos a ca. 30 kHz sob ressonâncias de dobramento usando cristais PEs com 0.5 mm de espessura. Medicoes de densidade de ruido magnetico equivalente demosntraram valores de ate 153 pT/Hz1/2 a 1 kHz (modo quasi-estatico) e 524 fT/Hz1/2 sob condicoes de ressonância. E de esperar que uma otimizacao adicional das tecnicas de fabrico, geometria dos compositos e circuitos de detencao possa permitir reduzir estes valores ate pelo menos 10 pT/Hz1/2 e 250 fT/Hz1/2, respetivamente, e a frequencia de ressonância em pelo menos duas ordens de grandeza. Estes sistemas poderao assim no futuro ser usados em sensores vetoriais de campo magnetico simples e sensiveis, passivos e estaveis e operaveis a elevadas temperaturas. None

  17. Chemicals from the Practice of Healthcare: Challenges and Unknowns Posed by Residues in the Environment

    EPA Science Inventory

    Medications have unique signatures - real and metaphorical fingerprints, footprints, and shadows. Signatures imparted by manufacturers use distinctive combinations of shapes, colors, and imprints. These serve as rough first tests to aid in visually identifying the types and quant...

  18. Autonomous Vision-based Rotorcraft Landing and Accurate Aerial Terrain Mapping in an Unknown Environment

    DTIC Science & Technology

    2007-01-22

    requirements for the degree of Master of Science, Plan II. Approval for the Report and Comprehensive Examination: Committee: Professor S. Shankar Sastry...13 2.4 Plans for the high-level planner. . . . . . . . . . . . . . . . . . . . . . . . 14 3.1 Idealized flight for purposes of analyzing...Stamping In order to use the RMFPP algorithm, we must first motion stamp each image, i.e. de - termine the orientation and position of the camera when

  19. Adaptive fuzzy prescribed performance control for MIMO nonlinear systems with unknown control direction and unknown dead-zone inputs.

    PubMed

    Shi, Wuxi; Luo, Rui; Li, Baoquan

    2017-01-01

    In this study, an adaptive fuzzy prescribed performance control approach is developed for a class of uncertain multi-input and multi-output (MIMO) nonlinear systems with unknown control direction and unknown dead-zone inputs. The properties of symmetric matrix are exploited to design adaptive fuzzy prescribed performance controller, and a Nussbaum-type function is incorporated in the controller to estimate the unknown control direction. This method has two prominent advantages: it does not require the priori knowledge of control direction and only three parameters need to be updated on-line for this MIMO systems. It is proved that all the signals in the resulting closed-loop system are bounded and that the tracking errors converge to a small residual set with the prescribed performance bounds. The effectiveness of the proposed approach is validated by simulation results. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  20. Red Pine Pocket Mortality - Unknown Cause (Pest Alert)

    Treesearch

    USDA Forest Service

    1985-01-01

    Continuing mortality of red pine from an unknown cause has been observed in 30 to 40 year old plantations in southern and west central Wisconsin. A single tree or small group of trees die, followed by mortality of adjacent trees. These circular pockets of dead trees expand up to 0.3 acre per year.

  1. 28. Photocopy of photograph dated ca. 1940; photographer unknown; original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. Photocopy of photograph dated ca. 1940; photographer unknown; original filed as MR2.9/SP8/r373 in Audio-Visual Collection of Minnesota Historical Society, St. Paul; WEST SIDE AFTER SECOND-STORY ADDITION; LOOKING EAST - Northwest Airways Hangar & Administration Building, 590 Bayfield Street, St. Paul Downtown Airport (Holman), Saint Paul, Ramsey County, MN

  2. 26. Photocopy of photograph dated 1930; photographer unknown; original filed ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. Photocopy of photograph dated 1930; photographer unknown; original filed as MR2.9/SP8/p343 in Audio-Visual Collection of Minnesota Historical Society, St. Paul; THREE-QUARTER VIEW SHOWING WEST SIDE AND SOUTH FRONT SHORTLY AFTER COMPLETION; LOOKING NORTHEAST - Northwest Airways Hangar & Administration Building, 590 Bayfield Street, St. Paul Downtown Airport (Holman), Saint Paul, Ramsey County, MN

  3. 29. Photocopy of photograph dated 1930; photographer unknown; original filed ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. Photocopy of photograph dated 1930; photographer unknown; original filed as HE17/p7 in Audio-Visual Collection of Minnesota Historical Society, St. Paul; HANGAR AREA, INTERIOR, SHOWING LONGITUDINAL 'CARRYING' TRUSS AND CANTILEVERED SECTION OF ROOF TRUSSES; LOOKING NORTHWEST FROM SOUTHEAST FRONT CORNER - Northwest Airways Hangar & Administration Building, 590 Bayfield Street, St. Paul Downtown Airport (Holman), Saint Paul, Ramsey County, MN

  4. 25. Photographic copy of undated photo; Photographer unknown; Original in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. Photographic copy of undated photo; Photographer unknown; Original in Rath collection at Iowa State University Libraries, Ames, Iowa; Filed under: Rath Packing Company, Printed Photographs, Symbol M, Box 2; REMOVING HIDES ON THE SKINNING TABLE; CARCASSES IN HALF-HOIST POSITION; LOOKING SOUTH - Rath Packing Company, Beef Killing Building, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

  5. 24. Photographic copy of undated photo; Photographer unknown; Original in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. Photographic copy of undated photo; Photographer unknown; Original in Rath collection at Iowa State University Libraries, Ames, Iowa; Filed under: Rath Packing Company, Printed Photographs, Symbol M, Box 2; REMOVING HIDES ON THE MOVING SKINNING TABLE; LOOKING NORTH - Rath Packing Company, Beef Killing Building, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

  6. Photocopy of photograph (from NBPPNSY) photographer unknown, 1988 view east ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of photograph (from NBP-PNSY) photographer unknown, 1988 view east of marine railway (Haer no. Pa-387-W). The railway was being dismantled at the time this photograph was taken. - Naval Base Philadelphia-Philadelphia Naval Shipyard, League Island, Philadelphia, Philadelphia County, PA

  7. 44. Photocopy of photograph, photographer unknown, 1415 June 1929 (original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. Photocopy of photograph, photographer unknown, 14-15 June 1929 (original print located at Utah State Historical Society Photograph Collection, Salt Lake City UT). DEDICATION CEREMONY AT BRIDGE. - Navajo Bridge, Spanning Colorado River at U.S. Highway 89 Alternate, Page, Coconino County, AZ

  8. 185. Photocopy of drawing, Twin Falls Canal Company, date unknown. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    185. Photocopy of drawing, Twin Falls Canal Company, date unknown. MILNER DAM CROSS SECTION PLAN, TWIN FALLS COUNTY, MILNER, IDAHO; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  9. 194. Photocopy of drawing, Twin Falls Canal Company, date unknown. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    194. Photocopy of drawing, Twin Falls Canal Company, date unknown. PROFILE AND GATE PLAN, NORTH ISLAND CROSS SECTION OF DAM, TWIN FALLS COUNTY, MILNER, IDAHO; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  10. 193. Photocopy of Photograph, Twin Falls Canal Company, date unknown. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    193. Photocopy of Photograph, Twin Falls Canal Company, date unknown. MILNER DAM PROFILE, TWIN FALLS COUNTY, MILNER, IDAHO; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  11. 195. Photocopy of drawing, Twin Falls Canal Company, date unknown. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    195. Photocopy of drawing, Twin Falls Canal Company, date unknown. PLAN OF CONSTRUCTION AREA PLANT, TWIN FALLS COUNTY, MILNER, IDAHO; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  12. 186. Photocopy of drawing, Twin Falls Canal Company, date unknown. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    186. Photocopy of drawing, Twin Falls Canal Company, date unknown. DRY CREEK RESERVOIR, CASSIA COUNTY (NOW TWIN FALLS COUNTY); MAP. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  13. 192. Photocopy of drawing, Twin Falls Canal Company, date unknown. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    192. Photocopy of drawing, Twin Falls Canal Company, date unknown. TOPOGRAPHICAL MAP (DAM DRAWN IN), MILNER SITE, TWIN FALLS COUNTY, MILNER, IDAHO; RIGHT SIDE OF MAP (LEFT ON ID-15-183). - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  14. 189. Photocopy of drawing, Twin Falls Canal Company, date unknown. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    189. Photocopy of drawing, Twin Falls Canal Company, date unknown. ROCK CREEK CROSSING, LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  15. 191. Photocopy of drawing, Twin Falls Canal Company, date unknown. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    191. Photocopy of drawing, Twin Falls Canal Company, date unknown. SPILLWAY GATES, MILNER DAM, TWIN FALLS COUNTY, MILNER, IDAHO; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  16. 190. Photocopy of drawing, Twin Falls Canal Company, date unknown. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    190. Photocopy of drawing, Twin Falls Canal Company, date unknown. GENERAL PLAN OF MILNER DAM TUNNELS, TWIN FALLS COUNTY, MILNER, IDAHO; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  17. 187. Photocopy of drawing, Twin Falls Canal Company, date unknown. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    187. Photocopy of drawing, Twin Falls Canal Company, date unknown. TOPOGRAPHICAL MAP OF MILNER DAM LOCATION, TWIN FALLS COUNTY, MILNER, IDAHO; BLUEPRINT MAP. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  18. Unknown Gases: Student-Designed Experiments in the Introductory Laboratory.

    ERIC Educational Resources Information Center

    Hanson, John; Hoyt, Tim

    2002-01-01

    Introductory students design and carry-out experimental procedures to determine the identity of three unknown gases from a list of eight possibilities: air, nitrogen, oxygen, argon, carbon dioxide, helium, methane, and hydrogen. Students are excited and motivated by the opportunity to come up with their own experimental approach to solving a…

  19. 8. Photocopy of photograph, date unknown (original print on file ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Photocopy of photograph, date unknown (original print on file at U.S. Army Intelligence Security Command, Fort Belvoir, Virginia). VIEW OF SULLINS COLLEGE, BRISTOL, VIRGINIA. SULLINS COLLEGE PRESIDENT WILLIAM MARTIN FOUNDED ARLINGTON HALL JUNIOR COLLEGE, AND APPEARS TO HAVE LOOSELY BASED THE DESIGN OF THE NEW SCHOOL'S BUILDINGS UPON THOSE AT SULLINS. - Arlington Hall Station, 4000 Arlington Boulevard, Arlington, Arlington County, VA

  20. 15. Photocopy of color photograph (Photographer unknown, 1974) SACRISTY ATTIC, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Photocopy of color photograph (Photographer unknown, 1974) SACRISTY ATTIC, LOOKING SOUTHWEST. NOTE RAMMED EARTH WALL (NORTH WALL OF CHANCEL) AT LEFT; HOLES WERE LEFT BY WOODEN BRACES USED TO HOLD WALL FORMS DURING CONSTRUCTION - Church of the Holy Cross, State Route 261, Stateburg, Sumter County, SC

  1. 42. Photocopy of photograph (Pentran file), photographer and date unknown ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. Photocopy of photograph (Pentran file), photographer and date unknown (circa 1950). Shows Trolley Barn in background and Administration Building on right. VIEW SOUTH - Newport News & Old Point Railway & Electric Company, Trolley Barn & Administration Building, 3400 Victoria Boulevard, Hampton, Hampton, VA

  2. 3. Photocopy of 184060 oil painting, artist unknown (from Chester ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Photocopy of 1840-60 oil painting, artist unknown (from Chester County Historical Society, West Chester, Pennsylvania) Photocopy taken by Ned Goode, July 1958 SOUTH FRONT AND EAST SIDE CIRCA 1850 - West Chester Young Ladies Seminary, 300 Maple Avenue, West Chester, Chester County, PA

  3. 6. Photographic copy of historic photograph (date and photograph unknown) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Photographic copy of historic photograph (date and photograph unknown) of upper dam showing retaining walls (original in possession of United States Department of Agriculture-Forest Service-Allegheny National Forest). VIEW WEST - Loleta Recreation Area, Upper Dam, 6 miles Southeast of interesection of State Route 24041 & State Route 66, Loleta, Elk County, PA

  4. 6. Photographic copy of photograph. No date. Photographer unknown. (Source: ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Photographic copy of photograph. No date. Photographer unknown. (Source: SCIP office, Coolidge, AZ) CHINA WASH FLUME UNDER CONSTRUCTION - San Carlos Irrigation Project, China Wash Flume, Main (Florence-Case Grande) Canal at Station 137+00, T4S, R10E, S14, Coolidge, Pinal County, AZ

  5. Photographic copy of photograph, photographer unknown, August 1912 (original print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photographic copy of photograph, photographer unknown, August 1912 (original print located at U.S. Bureau of Reclamation Upper Columbia Area Office, Yakima, Washington). "METHOD OF CONSTRUCTING DAM AFTER REMOVING OF TRESTLE" - Kachess Dam, Kachess River, 1.5 miles north of Interstate 90, Easton, Kittitas County, WA

  6. Photographic copy of photograph, photographer unknown, August 1912 (original print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photographic copy of photograph, photographer unknown, August 1912 (original print located at U.S. Bureau of Reclamation Upper Columbia Area Office, Yakima, Washington). "A VIEW OF METHOD OF DAM CONSTRUCTION" - Kachess Dam, Kachess River, 1.5 miles north of Interstate 90, Easton, Kittitas County, WA

  7. 40. Photocopy of building model photograph, ca., 1974, photographer unknown. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. Photocopy of building model photograph, ca., 1974, photographer unknown. Original photograph property of United States Air Force, 21" Space Command. CAPE COD AIR STATION PAVE PAWS FACILITY MODEL - ELEVATION SHOWING FLOOR AND EQUIPMENT LAYOUT. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  8. 39. Photocopy of building model photograph, ca. 1974, photographer unknown. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    39. Photocopy of building model photograph, ca. 1974, photographer unknown. Original photograph property of United States Air Force, 21" Space Command. CAPE COD AIR STATION PAVE PAWS FACILITY MODEL - SHOWING "A" AND "B" FACES. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  9. 41. Photocopy of progress photograph ca. 1974, photographer unknown. Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. Photocopy of progress photograph ca. 1974, photographer unknown. Original photograph Property of United States Air Force, 21" Space Command. This is the source for views 41 to 47. CAPE COD AIR STATION PAVE PAWS FACILITY - SHOWING BUILDING "RED IRON" STEEL STRUCTURE NEARING COMPLETION. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  10. Teleportation of Unknown Superpositions of Collective Atomic Coherent States

    NASA Astrophysics Data System (ADS)

    Zheng, Shi-Biao

    2001-06-01

    We propose a scheme to teleport an unknown superposition of two atomic coherent states with different phases. Our scheme is based on resonant and dispersive atom-field interaction. Our scheme provides a possibility of teleporting macroscopic superposition states of many atoms first time. The project supported by National Natural Science Foundation of China under Grant No. 60008003

  11. Photographic copy of photograph, photographer unknown, 18 February 1908 (original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photographic copy of photograph, photographer unknown, 18 February 1908 (original print located at U.S. Bureau of Reclamation Upper Columbia Area Office, Yakima, Washington). "LAKE KACHESS CRIB DAM. TAKEN FROM UPSTREAM SIDE. 4 FEET OF SNOW" - Kachess Dam, 1904 Cascade Canal Company Crib Dam, Kachess River, 1.5 miles north of Interstate 90, Easton, Kittitas County, WA

  12. Dealing with Unknown Variables in Policy/Program Evaluation.

    ERIC Educational Resources Information Center

    Nagel, Stuart S.

    1983-01-01

    Threshold analysis (TA) is introduced as an evaluation model. TA converts unknown variables into questions as to whether a given benefit, cost, or success probability is more or less than a threshold, above which the proposed project would be profitable, and below which it would be unprofitable. (Author/PN)

  13. A Size Exclusion Chromatography Laboratory with Unknowns for Introductory Students

    ERIC Educational Resources Information Center

    McIntee, Edward J.; Graham, Kate J.; Colosky, Edward C.; Jakubowski, Henry V.

    2015-01-01

    Size exclusion chromatography is an important technique in the separation of biological and polymeric samples by molecular weight. While a number of laboratory experiments have been published that use this technique for the purification of large molecules, this is the first report of an experiment that focuses on purifying an unknown small…

  14. 42. Photocopy of photograph, photographer unknown, 12 September 1928 (original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. Photocopy of photograph, photographer unknown, 12 September 1928 (original print located at Arizona Department of Transportation, Phoenix AZ). BRIDGE IMMEDIATELY AFTER INSERTION OF CENTER PIN. - Navajo Bridge, Spanning Colorado River at U.S. Highway 89 Alternate, Page, Coconino County, AZ

  15. Photographic copy of photograph, date unknown (original print located at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photographic copy of photograph, date unknown (original print located at the History Office, U.S. Army South, Fort Clayton, Republic of Panama). Early view of Fort Sherman from boat dock with theater in background, facing southwest. - Fort Sherman, Toro Point on Limon Bay, Colon, Former Panama Canal Zone, CZ

  16. 197. Photocopy of drawing, Twin Falls, Canal Company, date unknown. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    197. Photocopy of drawing, Twin Falls, Canal Company, date unknown. GATE STEMS AND LIFTING DEVICES, NO COUNTY; BLUEPRINT SKETCHES. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  17. The Unknowns and Possible Implications of Mandatory Labeling.

    PubMed

    McFadden, Brandon R

    2017-01-01

    The National Bioengineered Food Disclosure Standard requires a mandatory label for genetically modified (GM) food. Currently, some aspects of the bill are unknown, including what constitutes a food to be considered GM. The costs associated with this legislation will depend on how actors in the food value chain respond. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. 19. Photographer unknown, circa 1950 'THE LOOP OVER' BRIDGE WAS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. Photographer unknown, circa 1950 'THE LOOP OVER' BRIDGE WAS CONSTRUCTED ON NEWFOUND GAP ROAD TO REPLACE A SERIES OF DANGEROUS SWITCHBACKS. THIS ENGINEERING FEATURE QUICKLY BECAME A POPULAR TOURIST ATTRACTION. - Great Smoky Mountains National Park Roads & Bridges, Gatlinburg, Sevier County, TN

  19. 37 CFR 260.7 - Unknown copyright owners.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2013-07-01 2013-07-01 false Unknown copyright owners. 260.7 Section 260.7 Patents, Trademarks, and Copyrights COPYRIGHT OFFICE, LIBRARY OF CONGRESS COPYRIGHT ARBITRATION ROYALTY PANEL RULES AND PROCEDURES RATES AND TERMS FOR PREEXISTING SUBSCRIPTION SERVICES' DIGITAL...

  20. 37 CFR 260.7 - Unknown copyright owners.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2012-07-01 2012-07-01 false Unknown copyright owners. 260.7 Section 260.7 Patents, Trademarks, and Copyrights COPYRIGHT OFFICE, LIBRARY OF CONGRESS COPYRIGHT ARBITRATION ROYALTY PANEL RULES AND PROCEDURES RATES AND TERMS FOR PREEXISTING SUBSCRIPTION SERVICES' DIGITAL...

  1. 37 CFR 260.7 - Unknown copyright owners.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Unknown copyright owners. 260.7 Section 260.7 Patents, Trademarks, and Copyrights COPYRIGHT OFFICE, LIBRARY OF CONGRESS COPYRIGHT ARBITRATION ROYALTY PANEL RULES AND PROCEDURES RATES AND TERMS FOR PREEXISTING SUBSCRIPTION SERVICES' DIGITAL...

  2. 37 CFR 382.7 - Unknown copyright owners.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....7 Section 382.7 Patents, Trademarks, and Copyrights COPYRIGHT ROYALTY BOARD, LIBRARY OF CONGRESS RATES AND TERMS FOR STATUTORY LICENSES RATES AND TERMS FOR DIGITAL TRANSMISSIONS OF SOUND RECORDINGS AND... SATELLITE DIGITAL AUDIO RADIO SERVICES Preexisting Subscription Services § 382.7 Unknown copyright owners...

  3. 37 CFR 260.7 - Unknown copyright owners.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2011-07-01 2011-07-01 false Unknown copyright owners. 260.7 Section 260.7 Patents, Trademarks, and Copyrights COPYRIGHT OFFICE, LIBRARY OF CONGRESS COPYRIGHT ARBITRATION ROYALTY PANEL RULES AND PROCEDURES RATES AND TERMS FOR PREEXISTING SUBSCRIPTION SERVICES' DIGITAL...

  4. 37 CFR 382.7 - Unknown copyright owners.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ....7 Section 382.7 Patents, Trademarks, and Copyrights COPYRIGHT ROYALTY BOARD, LIBRARY OF CONGRESS RATES AND TERMS FOR STATUTORY LICENSES RATES AND TERMS FOR DIGITAL TRANSMISSIONS OF SOUND RECORDINGS AND... SATELLITE DIGITAL AUDIO RADIO SERVICES Preexisting Subscription Services § 382.7 Unknown copyright owners...

  5. 37 CFR 382.7 - Unknown copyright owners.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ....7 Section 382.7 Patents, Trademarks, and Copyrights COPYRIGHT ROYALTY BOARD, LIBRARY OF CONGRESS RATES AND TERMS FOR STATUTORY LICENSES RATES AND TERMS FOR DIGITAL TRANSMISSIONS OF SOUND RECORDINGS AND... SATELLITE DIGITAL AUDIO RADIO SERVICES Preexisting Subscription Services § 382.7 Unknown copyright owners...

  6. 15. Photographic copy of photograph dated ca. 1929; Photographer unknown; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Photographic copy of photograph dated ca. 1929; Photographer unknown; Original in Rath collection at Grout Museum, Waterloo, Iowa; Filed under: Rath Packing Company, Box 4; THE RATH COMPLEX IN THE LATE 1920S; LOOKING WEST FROM 18TH STREET; LARGE BUILDING AT CENTER IS HOG KILL (BUILDING 40) - Rath Packing Company, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

  7. 5. VIEW EAST, height finder radar towers, radar tower (unknown ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW EAST, height finder radar towers, radar tower (unknown function), prime search radar tower, operations building, and central heating plant - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  8. 4. VIEW NORTHEAST, radar tower (unknown function), prime search radar ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW NORTHEAST, radar tower (unknown function), prime search radar tower, emergency power building, and height finder radar tower - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  9. 17. Photocopy of a photograph, source and date unknown GENERAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. Photocopy of a photograph, source and date unknown GENERAL VIEW OF FRONT FACADE OF MT. CLARE STATION; PASSENGER CAR SHOP IN REAR - Baltimore & Ohio Railroad, Mount Clare Passenger Car Shop, Southwest corner of Pratt & Poppleton Streets, Baltimore, Independent City, MD

  10. 45. Photocopy of photograph (Pentran file), photographer and date unknown ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. Photocopy of photograph (Pentran file), photographer and date unknown (circa 1900). A single truck, solid mahagony car which ran between Hampton, Phoebus and Old Point Comfort. - Newport News & Old Point Railway & Electric Company, Trolley Barn & Administration Building, 3400 Victoria Boulevard, Hampton, Hampton, VA

  11. 38. Photocopy of photograph (Pentran file), photographer unknown. Bus garage ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. Photocopy of photograph (Pentran file), photographer unknown. Bus garage to left now demolished. Trolley car drivers, maintenance personnel and management staff in 1915. VIEW SOUTH - Newport News & Old Point Railway & Electric Company, Trolley Barn & Administration Building, 3400 Victoria Boulevard, Hampton, Hampton, VA

  12. Lod score curves for phase-unknown matings.

    PubMed

    Hulbert-Shearon, T; Boehnke, M; Lange, K

    1996-01-01

    For a phase-unknown nuclear family, we show that the likelihood and lod score are unimodal, and we describe conditions under which the maximum occurs at recombination fraction theta = 0, theta = 1/2, and 0 < theta < 1/2. These simply stated necessary and sufficient conditions seem to have escaped the notice of previous statistical geneticists.

  13. 188. Photocopy of drawing, Twin Falls Canal Company, date unknown. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    188. Photocopy of drawing, Twin Falls Canal Company, date unknown. DETAILS OF GATE RAISING MECHANISM, NO COUNTY; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  14. Application of incremental unknowns to the Burgers equation

    NASA Technical Reports Server (NTRS)

    Choi, Haecheon; Temam, Roger

    1993-01-01

    In this article, we make a few remarks on the role that attractors and inertial manifolds play in fluid mechanics problems. We then describe the role of incremental unknowns for approximating attractors and inertial manifolds when finite difference multigrid discretizations are used. The relation with direct numerical simulation and large eddy simulation is also mentioned.

  15. 45. Photocopy of photograph, photographer unknown, 1415 June 1929 (original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. Photocopy of photograph, photographer unknown, 14-15 June 1929 (original print located at Arizona Department of Transportation, Phoenix AZ). AIRPLANE STUNT DURING DEDICATION CEREMONY AT BRIDGE. - Navajo Bridge, Spanning Colorado River at U.S. Highway 89 Alternate, Page, Coconino County, AZ

  16. Photographic copy of photograph, photographer unknown, ca. 1930 (original print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photographic copy of photograph, photographer unknown, ca. 1930 (original print located at Colorado Historical Society, Denver, Colorado). Overall view of Southern UTE Agency Boarding School, with boys dormitory at center. - Southern Ute Boarding School, Boy's Dormitory, Ouray & Capote Drives, Ignacio, La Plata County, CO

  17. Photographic copy of photograph, photographer unknown, ca. 1930 (original print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photographic copy of photograph, photographer unknown, ca. 1930 (original print located at Colorado Historical Society, Denver, Colorado). Overall views of Southern Ute Agency Boarding School, with boys' dormitory at left of lower view. - Southern Ute Boarding School, Boy's Dormitory, Ouray & Capote Drives, Ignacio, La Plata County, CO

  18. Photographic copy of photograph, photographer unknown, ca. 1915 (original print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photographic copy of photograph, photographer unknown, ca. 1915 (original print located at Southern Ute Agency, Bureau of Indian Affairs Office, Ignacio, Colorado). Overall view of Southern Ute Agency Boarding School, with main building (boy's dormitory) at right. - Southern Ute Boarding School, Boy's Dormitory, Ouray & Capote Drives, Ignacio, La Plata County, CO

  19. Photographic copy of photograph, photographer unknown, 1942 (original print located ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photographic copy of photograph, photographer unknown, 1942 (original print located at Southern UTE Agency, Bureau of Indian Affairs Office, Ignacio, Colorado). West front and south side of boy's dormitory. - Southern Ute Boarding School, Boy's Dormitory, Ouray & Capote Drives, Ignacio, La Plata County, CO

  20. Photographic copy of photograph, photographer unknown, 1942 (original print located ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photographic copy of photograph, photographer unknown, 1942 (original print located at Southern UTE Agency, Bureau of Indian Affairs Office, Ignacio, Colorado). East rear and north side of boy's dormitory. - Southern Ute Boarding School, Boy's Dormitory, Ouray & Capote Drives, Ignacio, La Plata County, CO

  1. 38. Photographic copy of photograph, photographer unknown, 26 March 1915 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. Photographic copy of photograph, photographer unknown, 26 March 1915 (original print located at U.S. Bureau of Reclamation Upper Columbia Area Office, Yakima, Washington). " Dredge after failure of control dam." - Keechelus Dam, Yakima River, 10 miles northwest of Easton, Easton, Kittitas County, WA

  2. 39. Photographic copy of photograph, photographer unknown, 26 March 1915 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    39. Photographic copy of photograph, photographer unknown, 26 March 1915 (original print located at U.S. Bureau of Reclamation Upper Columbia Area Office, Yakima, Washington). "View of control dam after failure." - Keechelus Dam, Yakima River, 10 miles northwest of Easton, Easton, Kittitas County, WA

  3. 1. Drop Structure on the Arizona Crosscut Canal. Photographer unknown, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Drop Structure on the Arizona Crosscut Canal. Photographer unknown, no date. Note that caption is incorrect: in relation to Camelback Mountain (rear), this can only be the Old Crosscut. Source: reprinted from the 13th Annual Report of the U.S. Geological Survey, 1893. - Old Crosscut Canal, North Side of Salt River, Phoenix, Maricopa County, AZ

  4. 402. Delineator Unknown May 2, 1933 STUDY FOR SUSPENSION TOWERS; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    402. Delineator Unknown May 2, 1933 STUDY FOR SUSPENSION TOWERS; SAN FRANCISCO - OAKLAND BAY BRIDGE; TIMOTHY L. PFLUEGER, ARTHUR BROWN JR., JOHN J. DONOVAN; BOARD OF CONSULTING ARCHITECTS; SCHEME 1A - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  5. 56. Photographer unknown February 1925 HUMBOLDT COUNTY, SECTION J, HIGHWAY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    56. Photographer unknown February 1925 HUMBOLDT COUNTY, SECTION J, HIGHWAY 1. HUM-1-J #36, SINKS ALONG OCEAN SHORE, 2-25. Stamped office copy. - Redwood National & State Parks Roads, California coast from Crescent City to Trinidad, Crescent City, Del Norte County, CA

  6. 54. Photographer unknown February 1925 HUMBOLDT COUNTY, SECTION J, HIGHWAY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    54. Photographer unknown February 1925 HUMBOLDT COUNTY, SECTION J, HIGHWAY 1. HUM-1-J #34, SINKS ALONG HIGH. NEAR OCEAN, 2-25. - Redwood National & State Parks Roads, California coast from Crescent City to Trinidad, Crescent City, Del Norte County, CA

  7. 359. Delineator Unknown April 1935 STATE OF CALIFORNIA; DEPARTMENT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    359. Delineator Unknown April 1935 STATE OF CALIFORNIA; DEPARTMENT OF PUBLIC WORKS; SAN FRANCISCO - OAKLAND BAY BRIDGE; BRIDGE RAILWAY SAN FRANCISCO LOOP; DETAILS OF VIADUCT; FINAL REPORT; DRG. NO. 92 - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  8. 7. Photocopy of photograph, date unknown. VIEW OF WEST HIGH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Photocopy of photograph, date unknown. VIEW OF WEST HIGH STREET BRIDGE OVER SOUTH BRANCH OF FRENCH CREEK, WITH PENN RAILROAD BRIDGE IN BACKGROUND. (Original in Union City Historical Museum.) 8'x10' enlargement from 4'x5' negative. - Bridge Street Bridge, Spanning Little French Creek at Bridge Street, Union City, Erie County, PA

  9. 404. Delineator Unknown June 1, 1933 STUDY FOR TOP OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    404. Delineator Unknown June 1, 1933 STUDY FOR TOP OF SUSPENSION TOWERS; SAN FRANCISCO OAKLAND BAY BRIDGE; TIMOTHY L. PFLUEGER, ARTHUR BROWN JR., JOHN J. DONOVAN; BOARD OF CONSULTING ARCHITECTS; SCHEME 7-A - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  10. 46. Photographic copy of photograph, photographer unknown, 24 July 1916 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    46. Photographic copy of photograph, photographer unknown, 24 July 1916 (original print located at U.S. Bureau of Reclamation Upper Columbia Area Office, Yakima, Washington). "Scheme for shelter for cransemen on bucyrus steam shovel." - Keechelus Dam, Yakima River, 10 miles northwest of Easton, Easton, Kittitas County, WA

  11. 403. Delineator Unknown May 2, 1933 STUDY FOR SUSPENSION TOWERS; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    403. Delineator Unknown May 2, 1933 STUDY FOR SUSPENSION TOWERS; SAN FRANCISCO - OAKLAND BAY BRIDGE; TIMOTHY L. PFLUEGER, ARTHUR BROWN JR., JOHN J. DONOVAN; BOARD OF CONSULTING ARCHITECTS; SCHEME 2 - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  12. 16 CFR 303.14 - Products containing unknown fibers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., secondhand materials, textile by-products, or waste materials of unknown, and for practical purposes... the fiber content disclosure otherwise required by the Act and regulations, indicate that such product is composed of miscellaneous scraps, rags, odd lots, textile by-products, secondhand materials (in...

  13. 380. Delineator Unknown December 1932 STATE OF CALIFORNIA; DEPARTMENT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    380. Delineator Unknown December 1932 STATE OF CALIFORNIA; DEPARTMENT OF PUBLIC WORKS; SAN FRANCISCO - OAKLAND BAY BRIDGE; CABLES & ATTACHMENTS WEST BAY CROSSING; CABLE BANDS; CONTRACT NO. 6A; DRAWING NO. 3 - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  14. 385. Delineator Unknown December 1932 STATE OF CALIFORNIA; DEPARTMENT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    385. Delineator Unknown December 1932 STATE OF CALIFORNIA; DEPARTMENT OF PUBLIC WORKS; SAN FRANCISCO - OAKLAND BAY BRIDGE; SUPERSTRUCTURE - WEST BAY CROSSING; ROCKER POSTS AND BEARING; CONTRACT NO. 6; DRAWINGS NO. 42 - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  15. 390. Delineator Unknown October 1933 STATE OF CALIFORNIA; DEPARTMENT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    390. Delineator Unknown October 1933 STATE OF CALIFORNIA; DEPARTMENT OF PUBLIC WORKS; SAN FRANCISCO - OAKLAND BAY BRIDGE; SUPERSTRUCTURE - EAST BAY CROSSING; SPANS YBI TO El - E9 TO El ; TYPICAL CROSSSECTION; CONTRACT NO. 7; SUP. DRAWING NO. 82 - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  16. 379. Delineator Unknown December 1932 STATE OF CALIFORNIA; DEPARTMENT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    379. Delineator Unknown December 1932 STATE OF CALIFORNIA; DEPARTMENT OF PUBLIC WORKS; SAN FRANCISCO - OAKLAND BAY BRIDGE; CABLES AND ATTACHMENTS - WEST BAY CROSSING; SPLAY CASTINGS; CONTRACT NO. 6A; DRAWING NO. 4 - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  17. Saliency-Guided Detection of Unknown Objects in RGB-D Indoor Scenes.

    PubMed

    Bao, Jiatong; Jia, Yunyi; Cheng, Yu; Xi, Ning

    2015-08-27

    This paper studies the problem of detecting unknown objects within indoor environments in an active and natural manner. The visual saliency scheme utilizing both color and depth cues is proposed to arouse the interests of the machine system for detecting unknown objects at salient positions in a 3D scene. The 3D points at the salient positions are selected as seed points for generating object hypotheses using the 3D shape. We perform multi-class labeling on a Markov random field (MRF) over the voxels of the 3D scene, combining cues from object hypotheses and 3D shape. The results from MRF are further refined by merging the labeled objects, which are spatially connected and have high correlation between color histograms. Quantitative and qualitative evaluations on two benchmark RGB-D datasets illustrate the advantages of the proposed method. The experiments of object detection and manipulation performed on a mobile manipulator validate its effectiveness and practicability in robotic applications.

  18. Bayesian source term determination with unknown covariance of measurements

    NASA Astrophysics Data System (ADS)

    Belal, Alkomiet; Tichý, Ondřej; Šmídl, Václav

    2017-04-01

    Determination of a source term of release of a hazardous material into the atmosphere is a very important task for emergency response. We are concerned with the problem of estimation of the source term in the conventional linear inverse problem, y = Mx, where the relationship between the vector of observations y is described using the source-receptor-sensitivity (SRS) matrix M and the unknown source term x. Since the system is typically ill-conditioned, the problem is recast as an optimization problem minR,B(y - Mx)TR-1(y - Mx) + xTB-1x. The first term minimizes the error of the measurements with covariance matrix R, and the second term is a regularization of the source term. There are different types of regularization arising for different choices of matrices R and B, for example, Tikhonov regularization assumes covariance matrix B as the identity matrix multiplied by scalar parameter. In this contribution, we adopt a Bayesian approach to make inference on the unknown source term x as well as unknown R and B. We assume prior on x to be a Gaussian with zero mean and unknown diagonal covariance matrix B. The covariance matrix of the likelihood R is also unknown. We consider two potential choices of the structure of the matrix R. First is the diagonal matrix and the second is a locally correlated structure using information on topology of the measuring network. Since the inference of the model is intractable, iterative variational Bayes algorithm is used for simultaneous estimation of all model parameters. The practical usefulness of our contribution is demonstrated on an application of the resulting algorithm to real data from the European Tracer Experiment (ETEX). This research is supported by EEA/Norwegian Financial Mechanism under project MSMT-28477/2014 Source-Term Determination of Radionuclide Releases by Inverse Atmospheric Dispersion Modelling (STRADI).

  19. Protecting unknown two-qubit entangled states by nesting Uhrig's dynamical decoupling sequences

    SciTech Connect

    Mukhtar, Musawwadah; Soh, Wee Tee; Saw, Thuan Beng

    2010-11-15

    Future quantum technologies rely heavily on good protection of quantum entanglement against environment-induced decoherence. A recent study showed that an extension of Uhrig's dynamical decoupling (UDD) sequence can (in theory) lock an arbitrary but known two-qubit entangled state to the Nth order using a sequence of N control pulses [Mukhtar et al., Phys. Rev. A 81, 012331 (2010)]. By nesting three layers of explicitly constructed UDD sequences, here we first consider the protection of unknown two-qubit states as superposition of two known basis states, without making assumptions of the system-environment coupling. It is found that the obtained decoherence suppression canmore » be highly sensitive to the ordering of the three UDD layers and can be remarkably effective with the correct ordering. The detailed theoretical results are useful for general understanding of the nature of controlled quantum dynamics under nested UDD. As an extension of our three-layer UDD, it is finally pointed out that a completely unknown two-qubit state can be protected by nesting four layers of UDD sequences. This work indicates that when UDD is applicable (e.g., when the environment has a sharp frequency cutoff and when control pulses can be taken as instantaneous pulses), dynamical decoupling using nested UDD sequences is a powerful approach for entanglement protection.« less

  20. Eosinophilic pustular folliculitis: a sterile folliculitis of unknown cause?

    PubMed

    Brenner, S; Wolf, R; Ophir, J

    1994-08-01

    Eosinophilic pustular folliculitis (EPF) was initially defined as a sterile folliculitis of unknown cause. Because attempts to demonstrate bacterial organisms have been unsuccessful, and antibiotic therapy is usually ineffective, a bacterial infection is not considered a plausible causative factor for this disease. Our purpose was to describe five patients with the clinical and histologic characteristics of EPF and to report the results of bacterial cultures. Biopsy specimens were examined and pustules were cultured. In three of the five patients, Pseudomonas infection of the hair follicle was the cause of the disease as proven by repeated cultures and the response to specific therapy. Three patients had a systemic disorder known to cause immunologic alteration: AIDS in one and a myeloproliferative disorder in two. Although EPF was initially defined as a sterile folliculitis of unknown origin, three of our patients had an identifiable and treatable cause. We believe that these cases warrant the diagnosis of EPF.

  1. Quadrotor Control in the Presence of Unknown Mass Properties

    NASA Astrophysics Data System (ADS)

    Duivenvoorden, Rikky Ricardo Petrus Rufino

    Quadrotor UAVs are popular due to their mechanical simplicity, as well as their capability to hover and vertically take-off and land. As applications diversify, quadrotors are increasingly required to operate under unknown mass properties, for example as a multirole sensor platform or for package delivery operations. The work presented here consists of the derivation of a generalized quadrotor dynamic model without the typical simplifying assumptions on the first and second moments of mass. The maximum payload capacity of a quadrotor in hover, and the observability of the unknown mass properties are discussed. A brief introduction of L1 adaptive control is provided, and three different L 1 adaptive controllers were designed for the Parrot AR.Drone quadrotor. Their tracking and disturbance rejection performance was compared to the baseline nonlinear controller in experiments. Finally, the results of the combination of L1 adaptive control with iterative learning control are presented, showing high performance trajectory tracking under uncertainty.

  2. Dynamic Modeling from Flight Data with Unknown Time Skews

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.

    2016-01-01

    A method for estimating dynamic model parameters from flight data with unknown time skews is described and demonstrated. The method combines data reconstruction, nonlinear optimization, and equation-error parameter estimation in the frequency domain to accurately estimate both dynamic model parameters and the relative time skews in the data. Data from a nonlinear F-16 aircraft simulation with realistic noise, instrumentation errors, and arbitrary time skews were used to demonstrate the approach. The approach was further evaluated using flight data from a subscale jet transport aircraft, where the measured data were known to have relative time skews. Comparison of modeling results obtained from time-skewed and time-synchronized data showed that the method accurately estimates both dynamic model parameters and relative time skew parameters from flight data with unknown time skews.

  3. 27. Photocopy of photograph dated ca. 1940; photographer unknown; original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. Photocopy of photograph dated ca. 1940; photographer unknown; original filed as MR2.9/SP8/r374 in Audio-Visual Collection Minnesota Historical Society, St. Paul; THREE-QUARTER VIEW SHOWING WEST SIDE AND SOUTH FRONT AFTER SECOND-STORY ADDITION; LOOKING NORTHEAST - Northwest Airways Hangar & Administration Building, 590 Bayfield Street, St. Paul Downtown Airport (Holman), Saint Paul, Ramsey County, MN

  4. Spread-Spectrum Carrier Estimation With Unknown Doppler Shift

    NASA Technical Reports Server (NTRS)

    DeLeon, Phillip L.; Scaife, Bradley J.

    1998-01-01

    We present a method for the frequency estimation of a BPSK modulated, spread-spectrum carrier with unknown Doppler shift. The approach relies on a classic periodogram in conjunction with a spectral matched filter. Simulation results indicate accurate carrier estimation with processing gains near 40. A DSP-based prototype has been implemented for real-time carrier estimation for use in New Mexico State University's proposal for NASA's Demand Assignment Multiple Access service.

  5. Photocopy of photograph. Photographer unknown. Typical suggestion award photograph from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of photograph. Photographer unknown. Typical suggestion award photograph from the World War II period. Useful suggestions were awarded a $ 50 bond and usually a photo in the shipyard newspaper, the beacon. This photo shows an improved bilge block template layout table left to right: Stuart S. Sanders, Rosalie Moschella, Eddie Ormond, Lt. CDR. J.M. Ballinger, and A.A. Goldman. - Naval Base Philadelphia-Philadelphia Naval Shipyard, League Island, Philadelphia, Philadelphia County, PA

  6. Stochastic Online Learning in Dynamic Networks under Unknown Models

    DTIC Science & Technology

    2016-08-02

    Repeated Game with Incomplete Information, IEEE International Conference on Acoustics, Speech, and Signal Processing. 20-MAR-16, Shanghai, China...in a game theoretic framework for the application of multi-seller dynamic pricing with unknown demand models. We formulated the problem as an...infinitely repeated game with incomplete information and developed a dynamic pricing strategy referred to as Competitive and Cooperative Demand Learning

  7. Component spectra extraction from terahertz measurements of unknown mixtures.

    PubMed

    Li, Xian; Hou, D B; Huang, P J; Cai, J H; Zhang, G X

    2015-10-20

    The aim of this work is to extract component spectra from unknown mixtures in the terahertz region. To that end, a method, hard modeling factor analysis (HMFA), was applied to resolve terahertz spectral matrices collected from the unknown mixtures. This method does not require any expertise of the user and allows the consideration of nonlinear effects such as peak variations or peak shifts. It describes the spectra using a peak-based nonlinear mathematic model and builds the component spectra automatically by recombination of the resolved peaks through correlation analysis. Meanwhile, modifications on the method were made to take the features of terahertz spectra into account and to deal with the artificial baseline problem that troubles the extraction process of some terahertz spectra. In order to validate the proposed method, simulated wideband terahertz spectra of binary and ternary systems and experimental terahertz absorption spectra of amino acids mixtures were tested. In each test, not only the number of pure components could be correctly predicted but also the identified pure spectra had a good similarity with the true spectra. Moreover, the proposed method associated the molecular motions with the component extraction, making the identification process more physically meaningful and interpretable compared to other methods. The results indicate that the HMFA method with the modifications can be a practical tool for identifying component terahertz spectra in completely unknown mixtures. This work reports the solution to this kind of problem in the terahertz region for the first time, to the best of the authors' knowledge, and represents a significant advance toward exploring physical or chemical mechanisms of unknown complex systems by terahertz spectroscopy.

  8. 14. Photographic copy of photograph dated ca. 1925; Photographer unknown; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Photographic copy of photograph dated ca. 1925; Photographer unknown; Original in Rath collection at Iowa State University Libraries, Department of Special Collection, Ames, Iowa; Filed under: Rath Packing Company, Public Relations, Symbol N, Box 106, File 6: THE RATH COMPLEX IN THE MID 1920; LARGE BUILDING TO LEFT OF SMOKESTACK IS HOG KILL (BUILDING 40); LOOKING NORTH FROM ACROSS CEDAR RIVER - Rath Packing Company, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

  9. 13. Photocopy of photograph. Photographer unknown, circa 1940. Original photograph ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. Photocopy of photograph. Photographer unknown, circa 1940. Original photograph can be found in Marvine Colliery folder in the archives of the Lackawanna Historical Society, Scranton, Pennsylvania. VIEW SHOWING SOUTH AND EAST FACADES OF BREAKER, WITH OVERHEAD PIPING IN FOREGROUND AND RETAIL SCALES OFFICE AT FAR RIGHT, LOOKING NORTHWEST - Marvine Colliery, Breaker No. 2, West side Boulevard Avenue, between East Parker Street & Route 380, Scranton, Lackawanna County, PA

  10. 11. Photocopy of photograph. Photographer unknown, circa 1955. Original photograph ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Photocopy of photograph. Photographer unknown, circa 1955. Original photograph can be found in Marvine Colliery folder in the archives of the Lackawanna Historical Society, Scranton, Pennsylvania. VIEW SHOWING EAST AND NORTH FACADES OF BREAKER, WITH BOILER HOUSE AT FAR LEFT AND RETAIL SCALES OFFICE DIRECTLY EAST OF BREAKER, LOOKING SOUTHWEST - Marvine Colliery, Breaker No. 2, West side Boulevard Avenue, between East Parker Street & Route 380, Scranton, Lackawanna County, PA

  11. Persistent Surveillance of Transient Events with Unknown Statistics

    DTIC Science & Technology

    2016-12-18

    different bird species by a documentary maker is shown in Fig. 1. Additional examples of scenarios following this setting include robots patrolling the...persistent monitoring application in which a documentary maker would like to monitor three different species of birds appearing in three discrete, species...specific locations. Bird sightings at each location follow a stochastic process with a rate that is initially unknown to the documentary maker and must

  12. 11. photographer unknown 3 September 1984 AERIAL VIEW OF BONNEVILLE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. photographer unknown 3 September 1984 AERIAL VIEW OF BONNEVILLE PROJECT TAKEN AT 6000-FOOT ELEVATION. POWERHOUSE #1 AND NAVIGATION LOCK ARE IN UPPER/CENTER PART OF PHOTO, AND THE DAM/SPILLWAY IS IN LEFT/CENTER; THE SECOND POWERHOUSE IS PARTIALLY VISIBLE IN LOWER LEFT CORNER. COLUMBIA RIVER FLOWS FROM LEFT-TO-RIGHT. - Bonneville Project, Columbia River, 1 mile Northeast of Exit 40, off Interstate 84, Bonneville, Multnomah County, OR

  13. 11. Photographic copy of photograph, photographer unknown, 2 July 1938 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Photographic copy of photograph, photographer unknown, 2 July 1938 (original print located at U.S. Bureau of Reclamation Upper Columbia Area Office, Yakima, Washington). "Inspecting concrete on upstream face of Keechelus Dam spillway. Joseph Jacobs, consulting engineer; M.B. Lemon, Gatetender; Paul Taylor, assistant engineer; and C.H. Paul, consulting engineer." - Keechelus Dam, Spillway, Yakim River, 10 miles northwest of Easton, Easton, Kittitas County, WA

  14. Photocopy of photograph. Photographer unknown. Poster from the World War ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of photograph. Photographer unknown. Poster from the World War II period. During drives to encourage purchase of war bonds, posters featuring female shipyard workers were widely distributed purchasers were allowed one vote for each bond bought. Votes were cast and the woman who got the most votes was named "War Bond Girl." The contest was won by Kay McGinty, 4th row, 2nd column. - Naval Base Philadelphia-Philadelphia Naval Shipyard, League Island, Philadelphia, Philadelphia County, PA

  15. Fever of unknown origin (FUO) due to Legionnaire's disease.

    PubMed

    Muñoz-Gómez, Sigridh; Cunha, Burke A

    2015-01-01

    Fevers of unknown origin (FUOs) may be due to any of over 200 different disorders. We present a most unusual case of an FUO in a returning traveler from the Dominican Republic. Work-up for Q fever, Brucellosis, Bartonella, malaria and HIV were negative, but very highly elevated ESRs and ferritin levels suggested possible Legionnaire's disease. This is the third reported case of Legionnaire's disease presenting as an FUO. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Characterizing unknown systematics in large scale structure surveys

    SciTech Connect

    Agarwal, Nishant; Ho, Shirley; Myers, Adam D.

    Photometric large scale structure (LSS) surveys probe the largest volumes in the Universe, but are inevitably limited by systematic uncertainties. Imperfect photometric calibration leads to biases in our measurements of the density fields of LSS tracers such as galaxies and quasars, and as a result in cosmological parameter estimation. Earlier studies have proposed using cross-correlations between different redshift slices or cross-correlations between different surveys to reduce the effects of such systematics. In this paper we develop a method to characterize unknown systematics. We demonstrate that while we do not have sufficient information to correct for unknown systematics in the data,more » we can obtain an estimate of their magnitude. We define a parameter to estimate contamination from unknown systematics using cross-correlations between different redshift slices and propose discarding bins in the angular power spectrum that lie outside a certain contamination tolerance level. We show that this method improves estimates of the bias using simulated data and further apply it to photometric luminous red galaxies in the Sloan Digital Sky Survey as a case study.« less

  17. Analysis of multinomial models with unknown index using data augmentation

    USGS Publications Warehouse

    Royle, J. Andrew; Dorazio, R.M.; Link, W.A.

    2007-01-01

    Multinomial models with unknown index ('sample size') arise in many practical settings. In practice, Bayesian analysis of such models has proved difficult because the dimension of the parameter space is not fixed, being in some cases a function of the unknown index. We describe a data augmentation approach to the analysis of this class of models that provides for a generic and efficient Bayesian implementation. Under this approach, the data are augmented with all-zero detection histories. The resulting augmented dataset is modeled as a zero-inflated version of the complete-data model where an estimable zero-inflation parameter takes the place of the unknown multinomial index. Interestingly, data augmentation can be justified as being equivalent to imposing a discrete uniform prior on the multinomial index. We provide three examples involving estimating the size of an animal population, estimating the number of diabetes cases in a population using the Rasch model, and the motivating example of estimating the number of species in an animal community with latent probabilities of species occurrence and detection.

  18. Quantum key distribution with an unknown and untrusted source

    NASA Astrophysics Data System (ADS)

    Zhao, Yi; Qi, Bing; Lo, Hoi-Kwong

    2009-03-01

    The security of a standard bi-directional ``plug & play'' quantum key distribution (QKD) system has been an open question for a long time. This is mainly because its source is equivalently controlled by an eavesdropper, which means the source is unknown and untrusted. Qualitative discussion on this subject has been made previously. In this paper, we present the first quantitative security analysis on a general class of QKD protocols whose sources are unknown and untrusted. The securities of standard BB84 protocol, weak+vacuum decoy state protocol, and one-decoy decoy state protocol, with unknown and untrusted sources are rigorously proved. We derive rigorous lower bounds to the secure key generation rates of the above three protocols. Our numerical simulation results show that QKD with an untrusted source gives a key generation rate that is close to that with a trusted source. Our work is published in [1]. [4pt] [1] Y. Zhao, B. Qi, and H.-K. Lo, Phys. Rev. A, 77:052327 (2008).

  19. Identifying known unknowns using the US EPA's CompTox ...

    EPA Pesticide Factsheets

    Chemical features observed using high-resolution mass spectrometry can be tentatively identified using online chemical reference databases by searching molecular formulae and monoisotopic masses and then rank-ordering of the hits using appropriate relevance criteria. The most likely candidate “known unknowns,” which are those chemicals unknown to an investigator but contained within a reference database or literature source, rise to the top of a chemical list when rank-ordered by the number of associated data sources. The U.S. EPA’s CompTox Chemistry Dashboard is a curated and freely available resource for chemistry and computational toxicology research, containing more than 720,000 chemicals of relevance to environmental health science. In this research, the performance of the Dashboard for identifying “known unknowns” was evaluated against that of the online ChemSpider database, one of the primary resources used by mass spectrometrists, using multiple previously studied datasets reported in the peer-reviewed literature totaling 162 chemicals. These chemicals were examined using both applications via molecular formula and monoisotopic mass searches followed by rank-ordering of candidate compounds by associated references or data sources. A greater percentage of chemicals ranked in the top position when using the Dashboard, indicating an advantage of this application over ChemSpider for identifying known unknowns using data source ranking. Addition

  20. Comments on "Radiofrequency electromagnetic fields and some cancers of unknown etiology: An ecological study".

    PubMed

    Mortazavi, S A R; Mortazavi, Ghazal; Mortazavi, S M J

    2017-12-31

    This correspondence refers to the Science of the Total Environment article by Gonzalez-Rubio et al. entitled "Radiofrequency electromagnetic fields and some cancers of unknown etiology: An ecological study". Authors of this paper have presented the findings of their preliminary epidemiological study which combined epidemiology, statistics and geographical information systems (GIS). Gonzalez-Rubio et al. have analyzed the possible link between exposure to Radiofrequency Electromagnetic Fields (RF-EMF) in the city of Albacete, Spain and the incidence of cancers such as lymphomas, and brain tumors. The shortcomings of this study are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Prevalence and Impact of Unknown Diabetes in the ICU.

    PubMed

    Carpenter, David L; Gregg, Sara R; Xu, Kejun; Buchman, Timothy G; Coopersmith, Craig M

    2015-12-01

    Many patients with diabetes and their care providers are unaware of the presence of the disease. Dysglycemia encompassing hyperglycemia, hypoglycemia, and glucose variability is common in the ICU in patients with and without diabetes. The purpose of this study was to determine the impact of unknown diabetes on glycemic control in the ICU. Prospective observational study. Nine ICUs in an academic, tertiary hospital and a hybrid academic/community hospital. Hemoglobin A1c levels were ordered at all ICU admissions from March 1, 2011 to September 30, 2013. Electronic medical records were examined for a history of antihyperglycemic medications or International Classification of Diseases, 9th Edition diagnosis of diabetes. Patients were categorized as having unknown diabetes (hemoglobin A1c > 6.5%, without history of diabetes), no diabetes (hemoglobin A1c < 6.5%, without history of diabetes), controlled known diabetes (hemoglobin A1c < 6.5%, with documented history of diabetes), and uncontrolled known diabetes (hemoglobin A1c > 6.5%, with documented history of diabetes). None. A total of 15,737 patients had an hemoglobin A1c and medical record evaluable for the history of diabetes, and 5,635 patients had diabetes diagnosed by either medical history or an elevated hemoglobin A1c in the ICU. Of these, 1,460 patients had unknown diabetes, accounting for 26.0% of all patients with diabetes. This represented 41.0% of patients with an hemoglobin A1c > 6.5% and 9.3% of all ICU patients. Compared with patients without diabetes, patients with unknown diabetes had a higher likelihood of requiring an insulin infusion (44.3% vs 29.3%; p < 0.0001), a higher average blood glucose (172 vs 126 mg/dL; p < 0.0001), an increased percentage of hyperglycemia (19.7% vs 7.0%; blood glucose > 180 mg/dL; p < 0.0001) and hypoglycemia (8.9% vs 2.5%; blood glucose < 70 mg/dL; p < 0.0001), higher glycemic variability (55.6 vs 28.8, average of patient SD of glucose; p < 0.0001), and increased

  2. Fast grasping of unknown objects using cylinder searching on a single point cloud

    NASA Astrophysics Data System (ADS)

    Lei, Qujiang; Wisse, Martijn

    2017-03-01

    Grasping of unknown objects with neither appearance data nor object models given in advance is very important for robots that work in an unfamiliar environment. The goal of this paper is to quickly synthesize an executable grasp for one unknown object by using cylinder searching on a single point cloud. Specifically, a 3D camera is first used to obtain a partial point cloud of the target unknown object. An original method is then employed to do post treatment on the partial point cloud to minimize the uncertainty which may lead to grasp failure. In order to accelerate the grasp searching, surface normal of the target object is then used to constrain the synthetization of the cylinder grasp candidates. Operability analysis is then used to select out all executable grasp candidates followed by force balance optimization to choose the most reliable grasp as the final grasp execution. In order to verify the effectiveness of our algorithm, Simulations on a Universal Robot arm UR5 and an under-actuated Lacquey Fetch gripper are used to examine the performance of this algorithm, and successful results are obtained.

  3. Neurological autoantibodies in drug-resistant epilepsy of unknown cause.

    PubMed

    Tecellioglu, Mehmet; Kamisli, Ozden; Kamisli, Suat; Yucel, Fatma Ebru; Ozcan, Cemal

    2018-03-09

    Autoimmune epilepsy is a rarely diagnosed condition. Recognition of the underlying autoimmune condition is important, as these patients can be resistant to antiepileptic drugs. To determine the autoimmune and oncological antibodies in adult drug-resistant epilepsy of unknown cause and identify the clinical, radiological, and EEG findings associated with these antibodies according to data in the literature. Eighty-two patients with drug-resistant epilepsy of unknown cause were prospectively identified. Clinical features were recorded. The levels of anti-voltage-gated potassium channel complex (anti-VGKCc), anti-thyroid peroxidase (anti-TPO), anti-nuclear antibody (ANA), anti-glutamic acid decarboxylase (anti-GAD), anti-phospholipid IgG and IgM, anti-cardiolipin IgG and IgM, and onconeural antibodies were determined. Serum antibody positivity suggesting the potential role of autoimmunity in the aetiology was present in 17 patients with resistant epilepsy (22.0%). Multiple antibodies were found in two patients (2.6%). One of these patients (1.3%) had anti-VGKCc and ANA, whereas another (1.3%) had anti-VGKCc and anti-TPO. A single antibody was present in 15 patients (19.5%). Of the 77 patients finally included in the study, 4 had anti-TPO (5.2%), 1 had anti-GAD (1.3%), 4 had anti-VGKCc (5.2%) 8 had ANA (10.3%), and 2 had onconeural antibodies (2.6%) (1 patient had anti-Yo and 1 had anti-MA2/TA). The other antibodies investigated were not detected. EEG abnormality (focal), focal seizure incidence, and frequent seizures were more common in antibody-positive patients. Autoimmune factors may be aetiologically relevant in patients with drug-resistant epilepsy of unknown cause, especially if focal seizures are present together with focal EEG abnormality and frequent seizures.

  4. 7. Photographic copy of photograph, date unknown (original print in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Photographic copy of photograph, date unknown (original print in possession of James E. Zielinski Earth Tech, Huntsville, AL). Pan American World Airways, photographer. Aerial view (north to south) of missile launch area. Warhead handling building can be seen at the bottom center of the picture and the universal missile building in the middle right. In the distance can be seen the missile site control building and related structures - Stanley R. Mickelsen Safeguard Complex, Missile Launch Area, Within Exclusion Area, Nekoma, Cavalier County, ND

  5. Unknown beaked whale echolocation signals recorded off eastern New Zealand.

    PubMed

    Giorli, Giacomo; Goetz, Kimberly T; Delarue, Julien; Maxner, Emily; Kowarski, Katie A; Bruce Martin, Steven; McPherson, Craig

    2018-04-01

    The echolocation signals of most beaked whale species are still unknown. In fact, out of the 22 species comprising the family Ziphiidae, only the echolocation pulses for 7 species have been clearly described. This study describes two distinct beaked whale echolocation signals recorded in the Cook Strait region using passive acoustic technology. These signals differ from previously described Ziphiid species clicks. A description of the time-frequency characteristics of the two signals is provided. Understanding the characteristics of these signals is necessary to correctly identify species from their echolocation signals and enables future monitoring of beaked whales using passive acoustics techniques.

  6. Protein domains of unknown function are essential in bacteria.

    PubMed

    Goodacre, Norman F; Gerloff, Dietlind L; Uetz, Peter

    2013-12-31

    More than 20% of all protein domains are currently annotated as "domains of unknown function" (DUFs). About 2,700 DUFs are found in bacteria compared with just over 1,500 in eukaryotes. Over 800 DUFs are shared between bacteria and eukaryotes, and about 300 of these are also present in archaea. A total of 2,786 bacterial Pfam domains even occur in animals, including 320 DUFs. Evolutionary conservation suggests that many of these DUFs are important. Here we show that 355 essential proteins in 16 model bacterial species contain 238 DUFs, most of which represent single-domain proteins, clearly establishing the biological essentiality of DUFs. We suggest that experimental research should focus on conserved and essential DUFs (eDUFs) for functional analysis given their important function and wide taxonomic distribution, including bacterial pathogens. The functional units of proteins are domains. Typically, each domain has a distinct structure and function. Genomes encode thousands of domains, and many of the domains have no known function (domains of unknown function [DUFs]). They are often ignored as of little relevance, given that many of them are found in only a few genomes. Here we show that many DUFs are essential DUFs (eDUFs) based on their presence in essential proteins. We also show that eDUFs are often essential even if they are found in relatively few genomes. However, in general, more common DUFs are more often essential than rare DUFs.

  7. Atmospheric turbulence profiling with unknown power spectral density

    NASA Astrophysics Data System (ADS)

    Helin, Tapio; Kindermann, Stefan; Lehtonen, Jonatan; Ramlau, Ronny

    2018-04-01

    Adaptive optics (AO) is a technology in modern ground-based optical telescopes to compensate for the wavefront distortions caused by atmospheric turbulence. One method that allows to retrieve information about the atmosphere from telescope data is so-called SLODAR, where the atmospheric turbulence profile is estimated based on correlation data of Shack-Hartmann wavefront measurements. This approach relies on a layered Kolmogorov turbulence model. In this article, we propose a novel extension of the SLODAR concept by including a general non-Kolmogorov turbulence layer close to the ground with an unknown power spectral density. We prove that the joint estimation problem of the turbulence profile above ground simultaneously with the unknown power spectral density at the ground is ill-posed and propose three numerical reconstruction methods. We demonstrate by numerical simulations that our methods lead to substantial improvements in the turbulence profile reconstruction compared to the standard SLODAR-type approach. Also, our methods can accurately locate local perturbations in non-Kolmogorov power spectral densities.

  8. Fever of unknown origin: analysis of 71 consecutive cases.

    PubMed

    Colpan, Aylin; Onguru, Pinar; Erbay, Ayse; Akinci, Esragul; Cevik, Mustafa Aydin; Eren, Selim Sirri; Bodur, Hurrem

    2007-08-01

    Fever of unknown origin (FUO) is still an important problem in clinical practice. Evaluation of patient characteristics may clarify the utility of diagnostic tests and etiologies of FUO. Fever of unknown origin in 71 patients was investigated at Ankara Numune Education and Research Hospital in Turkey between February 2001 and December 2004. Mean hospital stay and fever duration was 20.5 days and 44 days, respectively. Etiologies of FUO were as follows: infections 32 (45.1%), collagen vascular disease 19 (26.8%), neoplasm 10 (14.1%), and miscellaneous diseases 4 (5.6%). Diagnosis remained obscure in 6 patients (8.5 %). Tuberculosis was found to be 40% of the infectious causes of FUO. Mean hospital stay and fever duration were prolonged in infectious cases. Female predominance was observed in collagen vascular diseases (P = 0.047). Splenomegaly and lymphadenopathy were common in the neoplasm group (P = 0.017, P = 0.017, respectively). Erythrocyte sedimentation rate, aspartate aminotransferase, alanine aminotransferase and lactate hydrogenase levels were elevated in patients with collagen vascular diseases. Nine (12.7%) patients died during the follow-up period. Hospital stay and fever duration were prolonged in the infectious group of FUO patients. Infectious diseases, particularly tuberculosis, were the most important cause of FUO in our series. Tuberculosis should be kept in mind as an important etiology of FUO countries where tuberculosis is endemic.

  9. Three-dimensional cinematography with control object of unknown shape.

    PubMed

    Dapena, J; Harman, E A; Miller, J A

    1982-01-01

    A technique for reconstruction of three-dimensional (3D) motion which involves a simple filming procedure but allows the deduction of coordinates in large object volumes was developed. Internal camera parameters are calculated from measurements of the film images of two calibrated crosses while external camera parameters are calculated from the film images of points in a control object of unknown shape but at least one known length. The control object, which includes the volume in which the activity is to take place, is formed by a series of poles placed at unknown locations, each carrying two targets. From the internal and external camera parameters, and from locations of the images of point in the films of the two cameras, 3D coordinates of the point can be calculated. Root mean square errors of the three coordinates of points in a large object volume (5m x 5m x 1.5m) were 15 mm, 13 mm, 13 mm and 6 mm, and relative errors in lengths averaged 0.5%, 0.7% and 0.5%, respectively.

  10. Group prioritisation with unknown expert weights in incomplete linguistic context

    NASA Astrophysics Data System (ADS)

    Cheng, Dong; Cheng, Faxin; Zhou, Zhili; Wang, Juan

    2017-09-01

    In this paper, we study a group prioritisation problem in situations when the expert weights are completely unknown and their judgement preferences are linguistic and incomplete. Starting from the theory of relative entropy (RE) and multiplicative consistency, an optimisation model is provided for deriving an individual priority vector without estimating the missing value(s) of an incomplete linguistic preference relation. In order to address the unknown expert weights in the group aggregating process, we define two new kinds of expert weight indicators based on RE: proximity entropy weight and similarity entropy weight. Furthermore, a dynamic-adjusting algorithm (DAA) is proposed to obtain an objective expert weight vector and capture the dynamic properties involved in it. Unlike the extant literature of group prioritisation, the proposed RE approach does not require pre-allocation of expert weights and can solve incomplete preference relations. An interesting finding is that once all the experts express their preference relations, the final expert weight vector derived from the DAA is fixed irrespective of the initial settings of expert weights. Finally, an application example is conducted to validate the effectiveness and robustness of the RE approach.

  11. On differential photometric reconstruction for unknown, isotropic BRDFs.

    PubMed

    Chandraker, Manmohan; Bai, Jiamin; Ramamoorthi, Ravi

    2013-12-01

    This paper presents a comprehensive theory of photometric surface reconstruction from image derivatives in the presence of a general, unknown isotropic BRDF. We derive precise topological classes up to which the surface may be determined and specify exact priors for a full geometric reconstruction. These results are the culmination of a series of fundamental observations. First, we exploit the linearity of chain rule differentiation to discover photometric invariants that relate image derivatives to the surface geometry, regardless of the form of isotropic BRDF. For the problem of shape-from-shading, we show that a reconstruction may be performed up to isocontours of constant magnitude of the gradient. For the problem of photometric stereo, we show that just two measurements of spatial and temporal image derivatives, from unknown light directions on a circle, suffice to recover surface information from the photometric invariant. Surprisingly, the form of the invariant bears a striking resemblance to optical flow; however, it does not suffer from the aperture problem. This photometric flow is shown to determine the surface up to isocontours of constant magnitude of the surface gradient, as well as isocontours of constant depth. Further, we prove that specification of the surface normal at a single point completely determines the surface depth from these isocontours. In addition, we propose practical algorithms that require additional initial or boundary information, but recover depth from lower order derivatives. Our theoretical results are illustrated with several examples on synthetic and real data.

  12. Chronic kidney disease of unknown etiology in agricultural communities.

    PubMed

    Almaguer, Miguel; Herrera, Raúl; Orantes, Carlos M

    2014-04-01

    In recent years, Central America, Egypt, India and Sri Lanka have reported a high prevalence of chronic kidney disease of unknown etiology in agricultural communities, predominantly among male farmworkers. This essay examines the disease's case definitions, epidemiology (disease burden, demographics, associated risk factors) and causal hypotheses, by reviewing published findings from El Salvador, Nicaragua, Costa Rica, Sri Lanka, Egypt and India. The range of confirmed chronic kidney disease prevalence was 17.9%-21.1%. Prevalence of reduced glomerular filtration (<60 mL/min/1.73 m2 body surface area) based on a single serum creatinine measurement was 0%-67% men and 0%-57% women. Prevalence was generally higher in male farmworkers aged 20-50 years, and varied by community economic activity and altitude. Cause was unknown in 57.4%-66.7% of patients. The dominant histopathological diagnosis was chronic tubulointerstitial nephritis. Associations were reported with agricultural work, agrochemical exposure, dehydration, hypertension, homemade alcohol use and family history of chronic kidney disease. There is no strong evidence for a single cause, and multiple environmental, occupational and social factors are probably involved. Further etiological research is needed, plus interventions to reduce preventable risk factors.

  13. Neurological Autoantibody Prevalence in Epilepsy of Unknown Etiology.

    PubMed

    Dubey, Divyanshu; Alqallaf, Abdulradha; Hays, Ryan; Freeman, Matthew; Chen, Kevin; Ding, Kan; Agostini, Mark; Vernino, Steven

    2017-04-01

    Autoimmune epilepsy is an underrecognized condition, and its true incidence is unknown. Identifying patients with an underlying autoimmune origin is critical because these patients' condition may remain refractory to conventional antiseizure medications but may respond to immunotherapy. To determine the prevalence of neurological autoantibodies (Abs) among adult patients with epilepsy of unknown etiology. Consecutive patients presenting to neurology services with new-onset epilepsy or established epilepsy of unknown etiology were identified. Serum samples were tested for autoimmune encephalitis Abs as well as thyroperoxidase (TPO) and glutamic acid decarboxylase 65 (GAD65) Abs. An antibody prevalence in epilepsy (APE) score based on clinical characteristics was assigned prospectively. Data were collected from June 1, 2015, to June 1, 2016. Presence of neurological Abs. A score based on clinical characteristics was assigned to estimate the probability of seropositivity prior to antibody test results. Good seizure outcome was estimated on the basis of significant reduction of seizure frequency at the first follow-up or seizure freedom. Of the 127 patients (68 males and 59 females) enrolled in the study, 15 were subsequently excluded after identification of an alternative diagnosis. Serum Abs suggesting a potential autoimmune etiology were detected in 39 (34.8%) cases. More than 1 Ab was detected in 7 patients (6.3%): 3 (2.7%) had TPO-Ab and voltage-gated potassium channel complex (VGKCc) Ab, 2 (1.8%) had GAD65-Ab and VGKCc-Ab, 1 had TPO-Ab and GAD65-Ab, and 1 had anti-Hu Ab and GAD65-Ab. Thirty-two patients (28.6%) had a single Ab marker. Among 112 patients included in the study, 15 (13.4%) had TPO-Ab, 14 (12.5%) had GAD65-Ab, 12 (10.7%) had VGKCc (4 of whom were positive for leucine-rich glioma-inactivated protein 1 [LGI1] Ab), and 4 (3.6%) had N-methyl-D-aspartate receptor (NMDAR) Ab. Even after excluding TPO-Ab and low-titer GAD65-Ab, Abs strongly suggesting an

  14. Biodiversity and global health—hubris, humility and the unknown

    NASA Astrophysics Data System (ADS)

    Stephens, Carolyn

    2012-03-01

    biodiversity and well-being; and the links of biodiversity to the green economy in the context of sustainable development and poverty alleviation. References [1] Schuiteman A et al 2011 Nocturne for an unknown pollinator: first description of a night-flowering orchid (Bulbophyllum nocturnum) Bot. J. Linean Soc. 167 344-50 [2] Kinver M and Gill V 2011 Botanists discover 'remarkable' night-flowering orchid BBC News Science and Environment (www.bbc.co.uk/news/science-environment-15818662) [3] Rudd M A 2011 Scientists' opinions on the global status and management of biological diversity Conserv. Biol. 25 1165-75 [4] Bottrill M C et al 2008 Is conservation triage just smart decision making? Trends Ecol. Evol. 23 649-54 [5] Parr M J et al 2009 Why we should aim for zero extinction Trends Ecol. Evol. 24 181 Bottrill M C et al 2009 Finite conservation funds mean triage is unavoidable Trends Ecol. Evol. 24 183-4 [6] Pushpangadan P and Behl H M 2005 Environment & Biodiversity: Agenda for Future (Lucknow: International Society of Environmental Botanists) (http://isebindia.com/icpep-3/icpep3-s-2.html) [7] Alves R and Rosa I 2007 Biodiversity, traditional medicine and public health: where do they meet? J. Ethnobiol. Ethnomed. 3 14 [8] Center for Biodiversity and Conservation 1997 Biodiversity and Human Health: A Guide for Policymakers (New York: American Museum of Natural History) [9] Chivian E 1997 Global environmental degradation and biodiversity loss: implications for human health Biodiversity and Human Health ed F Grifo and J Rosenthal (Washington, DC: Island) pp 7-38 [10] UNEP-WCMC 2011 Health and Well Being of Communities Directly Dependent on Ecosystem Goods and Services: An Indicator for the Convention on Biological Diversity (Cambridge: UNEP-World Conservation Monitoring Centre) [11] Nettleton C, Stephens C and Bristow F 2007 Utz Wachil: a study of indigenous perceptions of health and environment in five countries Ecohealth 4 461-772 [12] Jones G P et al 2004 Coral decline

  15. A learning-based semi-autonomous controller for robotic exploration of unknown disaster scenes while searching for victims.

    PubMed

    Doroodgar, Barzin; Liu, Yugang; Nejat, Goldie

    2014-12-01

    Semi-autonomous control schemes can address the limitations of both teleoperation and fully autonomous robotic control of rescue robots in disaster environments by allowing a human operator to cooperate and share such tasks with a rescue robot as navigation, exploration, and victim identification. In this paper, we present a unique hierarchical reinforcement learning-based semi-autonomous control architecture for rescue robots operating in cluttered and unknown urban search and rescue (USAR) environments. The aim of the controller is to enable a rescue robot to continuously learn from its own experiences in an environment in order to improve its overall performance in exploration of unknown disaster scenes. A direction-based exploration technique is integrated in the controller to expand the search area of the robot via the classification of regions and the rubble piles within these regions. Both simulations and physical experiments in USAR-like environments verify the robustness of the proposed HRL-based semi-autonomous controller to unknown cluttered scenes with different sizes and varying types of configurations.

  16. Fever of unknown origin (FUO): CMV infectious mononucleosis or lymphoma?

    PubMed

    Cunha, Burke A; Chawla, Karishma

    2018-07-01

    Fever of unknown origin (FUO) refers to fevers of > 101 °F that persist for > 3 weeks and remain undiagnosed after a focused inpatient or outpatient workup. FUO may be due to infectious, malignant/neoplastic, rheumatic/inflammatory, or miscellaneous disorders. The FUO category determines the focus of the diagnostic workup. In the case presented of an FUO in a young woman, there were clinical findings of both CMV infectious mononucleosis or a lymphoma, e.g., highly elevated ESR, elevated ferritin levels, and elevated ACE level, β-2 microglobulins. The indium scan showed intense splenic uptake. Lymph node biopsy, PET scan, and flow cytometry were negative for lymphoma. CMV infectious mononucleosis was the diagnosis, and she made a slow recovery.

  17. Parameter estimation of qubit states with unknown phase parameter

    NASA Astrophysics Data System (ADS)

    Suzuki, Jun

    2015-02-01

    We discuss a problem of parameter estimation for quantum two-level system, qubit system, in presence of unknown phase parameter. We analyze trade-off relations for mean square errors (MSEs) when estimating relevant parameters with separable measurements based on known precision bounds; the symmetric logarithmic derivative (SLD) Cramér-Rao (CR) bound and Hayashi-Gill-Massar (HGM) bound. We investigate the optimal measurement which attains the HGM bound and discuss its properties. We show that the HGM bound for relevant parameters can be attained asymptotically by using some fraction of given n quantum states to estimate the phase parameter. We also discuss the Holevo bound which can be attained asymptotically by a collective measurement.

  18. Zoonotic potential of emerging paramyxoviruses: knowns and unknowns

    PubMed Central

    Thibault, Patricia A; Watkinson, Ruth E; Moreira-Soto, Andres; Drexler, Jan Felix; Lee, Benhur

    2017-01-01

    The risk of spillover of enzootic paramyxoviruses, and the susceptibility of recipient human and domestic animal populations, are defined by a broad collection of ecological and molecular factors that interact in ways that are not yet fully understood. Nipah and Hendra viruses were the first highly-lethal zoonotic paramyxoviruses discovered in modern times, but other paramyxoviruses from multiple genera are present in bats and other reservoirs that have unknown potential to spill over into humans. We outline our current understanding of paramyxovirus reservoir hosts and the ecological factors that may drive spillover, and we explore the molecular barriers to spillover that emergent paramyxoviruses may encounter. By outlining what is known about enzootic paramyxovirus receptor usage, mechanisms of innate immune evasion, and other host-specific interactions, we highlight the breadth of unexplored avenues that may be important in understanding paramyxovirus emergence. PMID:28433050

  19. Distributed Synchronization Control of Multiagent Systems With Unknown Nonlinearities.

    PubMed

    Su, Shize; Lin, Zongli; Garcia, Alfredo

    2016-01-01

    This paper revisits the distributed adaptive control problem for synchronization of multiagent systems where the dynamics of the agents are nonlinear, nonidentical, unknown, and subject to external disturbances. Two communication topologies, represented, respectively, by a fixed strongly-connected directed graph and by a switching connected undirected graph, are considered. Under both of these communication topologies, we use distributed neural networks to approximate the uncertain dynamics. Decentralized adaptive control protocols are then constructed to solve the cooperative tracker problem, the problem of synchronization of all follower agents to a leader agent. In particular, we show that, under the proposed decentralized control protocols, the synchronization errors are ultimately bounded, and their ultimate bounds can be reduced arbitrarily by choosing the control parameter appropriately. Simulation study verifies the effectiveness of our proposed protocols.

  20. Distributed Multisensor Data Fusion under Unknown Correlation and Data Inconsistency

    PubMed Central

    Abu Bakr, Muhammad; Lee, Sukhan

    2017-01-01

    The paradigm of multisensor data fusion has been evolved from a centralized architecture to a decentralized or distributed architecture along with the advancement in sensor and communication technologies. These days, distributed state estimation and data fusion has been widely explored in diverse fields of engineering and control due to its superior performance over the centralized one in terms of flexibility, robustness to failure and cost effectiveness in infrastructure and communication. However, distributed multisensor data fusion is not without technical challenges to overcome: namely, dealing with cross-correlation and inconsistency among state estimates and sensor data. In this paper, we review the key theories and methodologies of distributed multisensor data fusion available to date with a specific focus on handling unknown correlation and data inconsistency. We aim at providing readers with a unifying view out of individual theories and methodologies by presenting a formal analysis of their implications. Finally, several directions of future research are highlighted. PMID:29077035

  1. Keratosis of unknown significance and leukoplakia: a preliminary study.

    PubMed

    Woo, Sook-Bin; Grammer, Rebecca L; Lerman, Mark A

    2014-12-01

    The objectives were to (1) determine the frequency of specific diagnoses in a series of white lesions, and (2) describe the nature of keratotic lesions that are neither reactive nor dysplastic. White lesions were analyzed and diagnosed as reactive keratoses, dysplastic/malignant, or keratoses of unknown significance (KUS). Of the 1251 specimens that were evaluated, 703 met criteria for inclusion, and approximately 75% were reactive, 10% dysplastic/malignant, and 14% KUS. Excluding reactive keratoses, 43% were dysplastic/malignant and 57% were KUS. Reactive keratoses were the most common white lesions followed by lichen planus. Dysplastic/malignant lesions constituted almost 50% of all true leukoplakias. KUS constituted the remaining cases and do not show typical reactive histopathology as well as clear dysplasia. They may represent evolving or devolving reactive keratoses but may also represent the very earliest dysplasia phenotype. Clinical findings may be helpful in differentiating the two. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. A 'range test' for determining scatterers with unknown physical properties

    NASA Astrophysics Data System (ADS)

    Potthast, Roland; Sylvester, John; Kusiak, Steven

    2003-06-01

    We describe a new scheme for determining the convex scattering support of an unknown scatterer when the physical properties of the scatterers are not known. The convex scattering support is a subset of the scatterer and provides information about its location and estimates for its shape. For convex polygonal scatterers the scattering support coincides with the scatterer and we obtain full shape reconstructions. The method will be formulated for the reconstruction of the scatterers from the far field pattern for one or a few incident waves. The method is non-iterative in nature and belongs to the type of recently derived generalized sampling schemes such as the 'no response test' of Luke-Potthast. The range test operates by testing whether it is possible to analytically continue a far field to the exterior of any test domain Omegatest. By intersecting the convex hulls of various test domains we can produce a minimal convex set, the convex scattering support of which must be contained in the convex hull of the support of any scatterer which produces that far field. The convex scattering support is calculated by testing the range of special integral operators for a sampling set of test domains. The numerical results can be used as an approximation for the support of the unknown scatterer. We prove convergence and regularity of the scheme and show numerical examples for sound-soft, sound-hard and medium scatterers. We can apply the range test to non-convex scatterers as well. We can conclude that an Omegatest which passes the range test has a non-empty intersection with the infinity-support (the complement of the unbounded component of the complement of the support) of the true scatterer, but cannot find a minimal set which must be contained therein.

  3. Altamira cave Paleolithic paintings harbor partly unknown bacterial communities.

    PubMed

    Schabereiter-Gurtner, Claudia; Saiz-Jimenez, Cesareo; Piñar, Guadalupe; Lubitz, Werner; Rölleke, Sabine

    2002-05-21

    Since it has been reported that microorganisms can affect painting pigments, Paleolithic painting microbiology deserves attention. The present study is the first report on the bacterial colonization of the valuable Paleolithic paintings in the famous Altamira cave (Spain). One sample taken from a painting area in the Polychromes Hall was analyzed culture-independently. This was the first time microbiologists were allowed to take sample material directly from Altamira paintings. Identification methods included PCR amplification of 16S rRNA genes (16S rDNA) and community fingerprinting by denaturing gradient gel electrophoresis (DGGE). The applied approach gave insight into a great bacterial taxonomic diversity, and allowed the detection of unexpected and unknown bacteria with potential effects on the conservation of the painting. Regarding the number of 29 visible DGGE bands in the community fingerprint, the numbers of analyzed clones described about 72% of the phylogenetic diversity present in the sample. Thirty-eight percent of the sequences analyzed were phylogenetically most closely related to cultivated bacteria, while the majority (62%) were most closely related to environmental 16S rDNA clones. Bacteria identified in Altamira were related with sequence similarities between 84.8 and 99.4% to members of the cosmopolitan Proteobacteria (52.3%), to members of the Acidobacterium division (23.8%), Cytophaga/Flexibacter/Bacteroides phylum (9.5%), green non-sulfur bacteria (4.8%), Planctomycetales (4.8%) and Actinobacteria (4.8%). The high number of clones most closely related to environmental 16S rDNA clones showed the broad spectrum of unknown and yet to be cultivated bacteria in Altamira cave.

  4. Bone metastases of unknown origin: epidemiology and principles of management.

    PubMed

    Piccioli, Andrea; Maccauro, Giulio; Spinelli, Maria Silvia; Biagini, Roberto; Rossi, Barbara

    2015-06-01

    Metastases are the most common malignancies involving bone; breast, prostate, lung and thyroid are the main sites of primary cancer. However, up to 30 % of patients present with bone metastases of unknown origin, where the site of the primary neoplasm cannot be identified at the time of diagnosis despite a thorough history, physical examination, appropriate laboratory testing and modern imaging technology (CT, MRI, PET). Sometimes only extensive histopathological investigations on bone specimens from biopsy can suggest the primary malignancy. At other times, a bone lesion can have such a highly undifferentiated histological appearance that a precise pathological classification on routine hematoxylin-eosin-stained section is not possible. The authors reviewed the relevant literature in an attempt to investigate the epidemiology of the histological primaries finally identified in patients with bone metastases from occult cancer, and a strategy of management and treatment of bone metastases from occult carcinomas is suggested. Lung, liver, pancreas and gastrointestinal tract are common sites for primary occult tumors. Adenocarcinoma is the main histological type, accounting for 70 % of all cases, while undifferentiated cancer accounts for 20 %. Over the past 30 years, lung cancer is the main causative occult primary for bone metastases and has a poor prognosis with an average survival of 4-8 months. Most relevant literature focuses on the need for standardized diagnostic workup, as surgery for bone lesions should be aggressive only when they are solitary and/or the occult primaries have a good prognosis; in these cases, identification of the primary tumor may be important and warrants special diagnostic efforts. However, in most cases, the primary site remains unknown, even after autopsy. Thus, orthopedic surgery has a mainly palliative role in preventing or stabilizing pathological fractures, relieving pain and facilitating the care of the patient in an attempt

  5. Smooth extrapolation of unknown anatomy via statistical shape models

    NASA Astrophysics Data System (ADS)

    Grupp, R. B.; Chiang, H.; Otake, Y.; Murphy, R. J.; Gordon, C. R.; Armand, M.; Taylor, R. H.

    2015-03-01

    Several methods to perform extrapolation of unknown anatomy were evaluated. The primary application is to enhance surgical procedures that may use partial medical images or medical images of incomplete anatomy. Le Fort-based, face-jaw-teeth transplant is one such procedure. From CT data of 36 skulls and 21 mandibles separate Statistical Shape Models of the anatomical surfaces were created. Using the Statistical Shape Models, incomplete surfaces were projected to obtain complete surface estimates. The surface estimates exhibit non-zero error in regions where the true surface is known; it is desirable to keep the true surface and seamlessly merge the estimated unknown surface. Existing extrapolation techniques produce non-smooth transitions from the true surface to the estimated surface, resulting in additional error and a less aesthetically pleasing result. The three extrapolation techniques evaluated were: copying and pasting of the surface estimate (non-smooth baseline), a feathering between the patient surface and surface estimate, and an estimate generated via a Thin Plate Spline trained from displacements between the surface estimate and corresponding vertices of the known patient surface. Feathering and Thin Plate Spline approaches both yielded smooth transitions. However, feathering corrupted known vertex values. Leave-one-out analyses were conducted, with 5% to 50% of known anatomy removed from the left-out patient and estimated via the proposed approaches. The Thin Plate Spline approach yielded smaller errors than the other two approaches, with an average vertex error improvement of 1.46 mm and 1.38 mm for the skull and mandible respectively, over the baseline approach.

  6. Decentralized adaptive control of interconnected nonlinear systems with unknown control directions.

    PubMed

    Huang, Jiangshuai; Wang, Qing-Guo

    2018-03-01

    In this paper, we propose a decentralized adaptive control scheme for a class of interconnected strict-feedback nonlinear systems without a priori knowledge of subsystems' control directions. To address this problem, a novel Nussbaum-type function is proposed and a key theorem is drawn which involves quantifying the interconnections of multiple Nussbaum-type functions of the subsystems with different control directions in a single inequality. Global stability of the closed-loop system and asymptotic stabilization of subsystems' output are proved and a simulation example is given to illustrate the effectiveness of the proposed control scheme. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  7. The Protein Interactome of Mycobacteriophage Giles Predicts Functions for Unknown Proteins.

    PubMed

    Mehla, Jitender; Dedrick, Rebekah M; Caufield, J Harry; Siefring, Rachel; Mair, Megan; Johnson, Allison; Hatfull, Graham F; Uetz, Peter

    2015-08-01

    Mycobacteriophages are viruses that infect mycobacterial hosts and are prevalent in the environment. Nearly 700 mycobacteriophage genomes have been completely sequenced, revealing considerable diversity and genetic novelty. Here, we have determined the protein complement of mycobacteriophage Giles by mass spectrometry and mapped its genome-wide protein interactome to help elucidate the roles of its 77 predicted proteins, 50% of which have no known function. About 22,000 individual yeast two-hybrid (Y2H) tests with four different Y2H vectors, followed by filtering and retest screens, resulted in 324 reproducible protein-protein interactions, including 171 (136 nonredundant) high-confidence interactions. The complete set of high-confidence interactions among Giles proteins reveals new mechanistic details and predicts functions for unknown proteins. The Giles interactome is the first for any mycobacteriophage and one of just five known phage interactomes so far. Our results will help in understanding mycobacteriophage biology and aid in development of new genetic and therapeutic tools to understand Mycobacterium tuberculosis. Mycobacterium tuberculosis causes over 9 million new cases of tuberculosis each year. Mycobacteriophages, viruses of mycobacterial hosts, hold considerable potential to understand phage diversity, evolution, and mycobacterial biology, aiding in the development of therapeutic tools to control mycobacterial infections. The mycobacteriophage Giles protein-protein interaction network allows us to predict functions for unknown proteins and shed light on major biological processes in phage biology. For example, Giles gp76, a protein of unknown function, is found to associate with phage packaging and maturation. The functions of mycobacteriophage-derived proteins may suggest novel therapeutic approaches for tuberculosis. Our ORFeome clone set of Giles proteins and the interactome data will be useful resources for phage interactomics. Copyright © 2015

  8. Kriging with Unknown Variance Components for Regional Ionospheric Reconstruction

    PubMed Central

    Huang, Ling; Zhang, Hongping; Xu, Peiliang; Geng, Jianghui; Wang, Cheng; Liu, Jingnan

    2017-01-01

    Ionospheric delay effect is a critical issue that limits the accuracy of precise Global Navigation Satellite System (GNSS) positioning and navigation for single-frequency users, especially in mid- and low-latitude regions where variations in the ionosphere are larger. Kriging spatial interpolation techniques have been recently introduced to model the spatial correlation and variability of ionosphere, which intrinsically assume that the ionosphere field is stochastically stationary but does not take the random observational errors into account. In this paper, by treating the spatial statistical information on ionosphere as prior knowledge and based on Total Electron Content (TEC) semivariogram analysis, we use Kriging techniques to spatially interpolate TEC values. By assuming that the stochastic models of both the ionospheric signals and measurement errors are only known up to some unknown factors, we propose a new Kriging spatial interpolation method with unknown variance components for both the signals of ionosphere and TEC measurements. Variance component estimation has been integrated with Kriging to reconstruct regional ionospheric delays. The method has been applied to data from the Crustal Movement Observation Network of China (CMONOC) and compared with the ordinary Kriging and polynomial interpolations with spherical cap harmonic functions, polynomial functions and low-degree spherical harmonic functions. The statistics of results indicate that the daily ionospheric variations during the experimental period characterized by the proposed approach have good agreement with the other methods, ranging from 10 to 80 TEC Unit (TECU, 1 TECU = 1 × 1016 electrons/m2) with an overall mean of 28.2 TECU. The proposed method can produce more appropriate estimations whose general TEC level is as smooth as the ordinary Kriging but with a smaller standard deviation around 3 TECU than others. The residual results show that the interpolation precision of the new proposed

  9. Kriging with Unknown Variance Components for Regional Ionospheric Reconstruction.

    PubMed

    Huang, Ling; Zhang, Hongping; Xu, Peiliang; Geng, Jianghui; Wang, Cheng; Liu, Jingnan

    2017-02-27

    Ionospheric delay effect is a critical issue that limits the accuracy of precise Global Navigation Satellite System (GNSS) positioning and navigation for single-frequency users, especially in mid- and low-latitude regions where variations in the ionosphere are larger. Kriging spatial interpolation techniques have been recently introduced to model the spatial correlation and variability of ionosphere, which intrinsically assume that the ionosphere field is stochastically stationary but does not take the random observational errors into account. In this paper, by treating the spatial statistical information on ionosphere as prior knowledge and based on Total Electron Content (TEC) semivariogram analysis, we use Kriging techniques to spatially interpolate TEC values. By assuming that the stochastic models of both the ionospheric signals and measurement errors are only known up to some unknown factors, we propose a new Kriging spatial interpolation method with unknown variance components for both the signals of ionosphere and TEC measurements. Variance component estimation has been integrated with Kriging to reconstruct regional ionospheric delays. The method has been applied to data from the Crustal Movement Observation Network of China (CMONOC) and compared with the ordinary Kriging and polynomial interpolations with spherical cap harmonic functions, polynomial functions and low-degree spherical harmonic functions. The statistics of results indicate that the daily ionospheric variations during the experimental period characterized by the proposed approach have good agreement with the other methods, ranging from 10 to 80 TEC Unit (TECU, 1 TECU = 1 × 10 16 electrons/m²) with an overall mean of 28.2 TECU. The proposed method can produce more appropriate estimations whose general TEC level is as smooth as the ordinary Kriging but with a smaller standard deviation around 3 TECU than others. The residual results show that the interpolation precision of the new proposed

  10. Saliency-Guided Detection of Unknown Objects in RGB-D Indoor Scenes

    PubMed Central

    Bao, Jiatong; Jia, Yunyi; Cheng, Yu; Xi, Ning

    2015-01-01

    This paper studies the problem of detecting unknown objects within indoor environments in an active and natural manner. The visual saliency scheme utilizing both color and depth cues is proposed to arouse the interests of the machine system for detecting unknown objects at salient positions in a 3D scene. The 3D points at the salient positions are selected as seed points for generating object hypotheses using the 3D shape. We perform multi-class labeling on a Markov random field (MRF) over the voxels of the 3D scene, combining cues from object hypotheses and 3D shape. The results from MRF are further refined by merging the labeled objects, which are spatially connected and have high correlation between color histograms. Quantitative and qualitative evaluations on two benchmark RGB-D datasets illustrate the advantages of the proposed method. The experiments of object detection and manipulation performed on a mobile manipulator validate its effectiveness and practicability in robotic applications. PMID:26343656

  11. Some news from the unknown soldier, the Peyer's patch macrophage.

    PubMed

    Wagner, Camille; Bonnardel, Johnny; Da Silva, Clément; Martens, Liesbet; Gorvel, Jean-Pierre; Lelouard, Hugues

    2018-01-31

    In mammals, macrophages (MF) are present in virtually all tissues where they serve many different functions linked primarily to the maintenance of homeostasis, innate defense against pathogens, tissue repair and metabolism. Although some of these functions appear common to all tissues, others are specific to the homing tissue. Thus, MF become adapted to perform particular functions in a given tissue. Accordingly, MF express common markers but also sets of tissue-specific markers linked to dedicated functions. One of the largest pool of MF in the body lines up the wall of the gut. Located in the small intestine, Peyer's patches (PP) are primary antigen sampling and mucosal immune response inductive sites. Surprisingly, although markers of intestinal MF, such as F4/80, have been identified more than 30 years ago, MF of PP escaped any kind of phenotypic description and remained "unknown" for decades. In absence of MF identification, the characterization of the PP mononuclear phagocyte system (MPS) functions has been impaired. However, taking into account that PP are privileged sites of entry for pathogens, it is important to understand how the latter are handled by and/or escape the PP MPS, especially MF, which role in killing invaders is well known. This review focuses on recent advances on the PP MPS, which have allowed, through new criteria of PP phagocyte subset identification, the characterization of PP MF origin, diversity, specificity, location and functions. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Developing Probabilistic Safety Performance Margins for Unknown and Underappreciated Risks

    NASA Technical Reports Server (NTRS)

    Benjamin, Allan; Dezfuli, Homayoon; Everett, Chris

    2015-01-01

    Probabilistic safety requirements currently formulated or proposed for space systems, nuclear reactor systems, nuclear weapon systems, and other types of systems that have a low-probability potential for high-consequence accidents depend on showing that the probability of such accidents is below a specified safety threshold or goal. Verification of compliance depends heavily upon synthetic modeling techniques such as PRA. To determine whether or not a system meets its probabilistic requirements, it is necessary to consider whether there are significant risks that are not fully considered in the PRA either because they are not known at the time or because their importance is not fully understood. The ultimate objective is to establish a reasonable margin to account for the difference between known risks and actual risks in attempting to validate compliance with a probabilistic safety threshold or goal. In this paper, we examine data accumulated over the past 60 years from the space program, from nuclear reactor experience, from aircraft systems, and from human reliability experience to formulate guidelines for estimating probabilistic margins to account for risks that are initially unknown or underappreciated. The formulation includes a review of the safety literature to identify the principal causes of such risks.

  13. A community of unknown, endophytic fungi in western white pine.

    PubMed

    Ganley, Rebecca J; Brunsfeld, Steven J; Newcombe, George

    2004-07-06

    The endophytic fungi of woody plants may be diverse as often claimed, and likewise, they may be functionally novel as demonstrated in a few studies. However, the endophyte taxa that are most frequently reported tend to belong to fungal groups composed of morphologically similar endophytes and parasites. Thus, it is plausible that endophytes are known (i.e., described) parasites in a latent phase within the host. If this null hypothesis were true, endophytes would represent neither additional fungal diversity distinct from parasite diversity nor a symbiont community likely to be novel ecologically. To be synonymous with parasites of the host, endophytes should at least be most closely related to those same parasites. Here we report that seven distinct parasites of Pinus monticola do not occur as endophytes. The majority of endophytes of P. monticola (90% of 2,019 cultures) belonged to one fungal family, the Rhytismataceae. However, not a single rhytismataceous endophyte was found to be most closely related by sequence homology to the three known rhytismataceous parasites of P. monticola. Similarly, neither endophytic Mycosphaerella nor endophytic Rhizosphaera isolates were most closely related to known parasites of P. monticola. Morphologically, the endophytes of P. monticola can be confounded with the parasites of the same host. However, they are actually most closely related to, but distinct from, parasites of other species of Pinus. If endophytes are generally unknown species, then estimates of 1 million endophytes (i.e., approximately 1 in 14 of all species of life) seem reasonable.

  14. [Claude Perrault, famous architect, unknown physician, untiring researcher].

    PubMed

    Hazard, Jean

    2007-01-01

    As a famous architect Charles Perrault persuaded Colbert to appoint a committee of the "Bâtiments du Roi" made up of three persons: Le Vau, Le Brun and one of his brothers Claude whose Louis XIV chose the plan. While Le Vau was busy in Versailles Perrault's influence became dominating. Although he was an unknown medical practitioner he managed to be allowed to practise and to teach medicine and to be a member of theses' jury for twenty five years. He was highly regarded by his colleagues who did not hesitate to hold a consultation. His trip in Bordeaux was consecrated to look after his brother but because of his numerous occupations he gave up practising medicine and he only treated the members of his family, his friends and some poor. He was a tireless researcher and at the "Académie des Sciences" he looked after the "Histoire naturelle des animaux" (Natural History of the Animals). In "Les Essais de Physique" he tackled numerous problems of physiology such as elasticity and contractility of arteries, studied the sense organs and did some experiments about blood transfusion. As an exceptional man he could practise the three of the occupations.

  15. Impedance spectroscopy for the detection and identification of unknown toxins

    NASA Astrophysics Data System (ADS)

    Riggs, B. C.; Plopper, G. E.; Paluh, J. L.; Phamduy, T. B.; Corr, D. T.; Chrisey, D. B.

    2012-06-01

    Advancements in biological and chemical warfare has allowed for the creation of novel toxins necessitating a universal, real-time sensor. We have used a function-based biosensor employing impedance spectroscopy using a low current density AC signal over a range of frequencies (62.5 Hz-64 kHz) to measure the electrical impedance of a confluent epithelial cell monolayer at 120 sec intervals. Madin Darby canine kidney (MDCK) epithelial cells were grown to confluence on thin film interdigitated gold electrodes. A stable impedance measurement of 2200 Ω was found after 24 hrs of growth. After exposure to cytotoxins anthrax lethal toxin and etoposide, the impedance decreased in a linear fashion resulting in a 50% drop in impedance over 50hrs showing significant difference from the control sample (~20% decrease). Immunofluorescent imaging showed that apoptosis was induced through the addition of toxins. Similarities of the impedance signal shows that the mechanism of cellular death was the same between ALT and etoposide. A revised equivalent circuit model was employed in order to quantify morphological changes in the cell monolayer such as tight junction integrity and cell surface area coverage. This model showed a faster response to cytotoxin (2 hrs) compared to raw measurements (20 hrs). We demonstrate that herein that impedance spectroscopy of epithelial monolayers serves as a real-time non-destructive sensor for unknown pathogens.

  16. PMS2 monoallelic mutation carriers: the known unknown

    PubMed Central

    Goodenberger, McKinsey L.; Thomas, Brittany C.; Riegert-Johnson, Douglas; Boland, C. Richard; Plon, Sharon E.; Clendenning, Mark; Ko Win, Aung; Senter, Leigha; Lipkin, Steven M.; Stadler, Zsofia K.; Macrae, Finlay A.; Lynch, Henry T.; Weitzel, Jeffrey N.; de la Chapelle, Albert; Syngal, Sapna; Lynch, Patrick; Parry, Susan; Jenkins, Mark A.; Gallinger, Steven; Holter, Spring; Aronson, Melyssa; Newcomb, Polly A.; Burnett, Terrilea; Le Marchand, Loïc; Pichurin, Pavel; Hampel, Heather; Terdiman, Jonathan P.; Lu, Karen H.; Thibodeau, Stephen; Lindor, Noralane M.

    2016-01-01

    Germline mutations in MLH1, MSH2, MSH6 and PMS2 have been shown to cause Lynch syndrome. The penetrance for cancer and tumor spectrum has been repeatedly studied and multiple professional societies have proposed clinical management guidelines for affected individuals. Several studies have demonstrated a reduced penetrance for monoallelic carriers of PMS2 mutations compared to the other mismatch repair (MMR) genes, but clinical management guidelines have largely proposed the same screening recommendations for all MMR gene carriers. The authors considered whether enough evidence existed to propose new screening guidelines specific to PMS2 mutation carriers with regard to age of onset and frequency of colonic screening. Published reports of PMS2 germline mutations were combined with unpublished cases from the authors’ research registries and clinical practices, and a discussion of potential modification of cancer screening guidelines was pursued. A total of 234 monoallelic PMS2 mutation carriers from 170 families were included. Approximately 8% of those with CRC were diagnosed under age 30 and each of these tumors presented on the left-side of the colon. As it is currently unknown what causes the early-onset of CRC in some families with monoallelic PMS2 germline mutations, the authors recommend against reducing cancer surveillance guidelines in families found having monoallelic PMS2 mutations in spite of the documented reduced penetrance. PMID:25856668

  17. PMS2 monoallelic mutation carriers: the known unknown.

    PubMed

    Goodenberger, McKinsey L; Thomas, Brittany C; Riegert-Johnson, Douglas; Boland, C Richard; Plon, Sharon E; Clendenning, Mark; Win, Aung Ko; Senter, Leigha; Lipkin, Steven M; Stadler, Zsofia K; Macrae, Finlay A; Lynch, Henry T; Weitzel, Jeffrey N; de la Chapelle, Albert; Syngal, Sapna; Lynch, Patrick; Parry, Susan; Jenkins, Mark A; Gallinger, Steven; Holter, Spring; Aronson, Melyssa; Newcomb, Polly A; Burnett, Terrilea; Le Marchand, Loïc; Pichurin, Pavel; Hampel, Heather; Terdiman, Jonathan P; Lu, Karen H; Thibodeau, Stephen; Lindor, Noralane M

    2016-01-01

    Germ-line mutations in MLH1, MSH2, MSH6, and PMS2 have been shown to cause Lynch syndrome. The penetrance of the cancer and tumor spectrum has been repeatedly studied, and multiple professional societies have proposed clinical management guidelines for affected individuals. Several studies have demonstrated a reduced penetrance for monoallelic carriers of PMS2 mutations compared with the other mismatch repair (MMR) genes, but clinical management guidelines have largely proposed the same screening recommendations for all MMR gene carriers. The authors considered whether enough evidence existed to propose new screening guidelines specific to PMS2 mutation carriers with regard to age at onset and frequency of colonic screening. Published reports of PMS2 germ-line mutations were combined with unpublished cases from the authors' research registries and clinical practices, and a discussion of potential modification of cancer screening guidelines was pursued. A total of 234 monoallelic PMS2 mutation carriers from 170 families were included. Approximately 8% of those with colorectal cancer (CRC) were diagnosed before age 30, and each of these tumors presented on the left side of the colon. As it is currently unknown what causes the early onset of CRC in some families with monoallelic PMS2 germline mutations, the authors recommend against reducing cancer surveillance guidelines in families found having monoallelic PMS2 mutations in spite of the reduced penetrance.Genet Med 18 1, 13-19.

  18. Viral Diseases in Zebrafish: What Is Known and Unknown

    PubMed Central

    Crim, Marcus J.; Riley, Lela K.

    2013-01-01

    Naturally occurring viral infections have the potential to introduce confounding variability that leads to invalid and misinterpreted data. Whereas the viral diseases of research rodents are well characterized and closely monitored, no naturally occurring viral infections have been characterized for the laboratory zebrafish (Danio rerio), an increasingly important biomedical research model. Despite the ignorance about naturally occurring zebrafish viruses, zebrafish models are rapidly expanding in areas of biomedical research where the confounding effects of unknown infectious agents present a serious concern. In addition, many zebrafish research colonies remain linked to the ornamental (pet) zebrafish trade, which can contribute to the introduction of new pathogens into research colonies, whereas mice used for research are purpose bred, with no introduction of new mice from the pet industry. Identification, characterization, and monitoring of naturally occurring viruses in zebrafish are crucial to the improvement of zebrafish health, the reduction of unwanted variability, and the continued development of the zebrafish as a model organism. This article addresses the importance of identifying and characterizing the viral diseases of zebrafish as the scope of zebrafish models expands into new research areas and also briefly addresses zebrafish susceptibility to experimental viral infection and the utility of the zebrafish as an infection and immunology model. PMID:23382345

  19. Ulysses operations at Jupiter - Planning for the unknown

    NASA Technical Reports Server (NTRS)

    Angold, N.; Beech, P.; Garcia-Perez, R.; Mcgarry, A.; Standley, S.

    1992-01-01

    The operational preparations for the Ulysses encounter with Jupiter are described with particular attention given to requirements for survival in the Jovian environment, ground-segment planning, a deep-space network, and encounter activities. It is concluded that the successful operation of the Ulysses spacecraft at Jupiter was the culmination of many years of activity, from spacecraft design and mission planning to the coordination of the encounter activities and production of the detailed timeline.

  20. Mapping of unknown industrial plant using ROS-based navigation mobile robot

    NASA Astrophysics Data System (ADS)

    Priyandoko, G.; Ming, T. Y.; Achmad, M. S. H.

    2017-10-01

    This research examines how humans work with teleoperated unmanned mobile robot inspection in industrial plant area resulting 2D/3D map for further critical evaluation. This experiment focuses on two parts, the way human-robot doing remote interactions using robust method and the way robot perceives the environment surround as a 2D/3D perspective map. ROS (robot operating system) as a tool was utilized in the development and implementation during the research which comes up with robust data communication method in the form of messages and topics. RGBD SLAM performs the visual mapping function to construct 2D/3D map using Kinect sensor. The results showed that the mobile robot-based teleoperated system are successful to extend human perspective in term of remote surveillance in large area of industrial plant. It was concluded that the proposed work is robust solution for large mapping within an unknown construction building.

  1. CUP Syndrome-Metastatic Malignancy with Unknown Primary Tumor.

    PubMed

    Zaun, Gregor; Schuler, Martin; Herrmann, Ken; Tannapfel, Andrea

    2018-03-09

    2-4% of newly diagnosed cases of malignant disease involve cancer of unknown primary (CUP). This mixed entity is one of the 6 most common types of malignant disease in Germany. Highly refined treatment strategies can now be offered to patients with CUP. This review is based on pertinent publications retrieved by a selective search in PubMed with an emphasis on articles from the past decade. The current guidelines and recommendations of specialty societies were also considered in the evaluation. CUP most commonly manifests itself as metastases to the lymph nodes, lungs, liver, or bones. With the aid of imaging studies, including functional hybrid imaging and further medical examination, a primary tumor can be discovered in up to 40% of patients initially diagnosed with CUP. Immunohistochemistry guided by histomorphology often enables precise characterization of the lesion and can be supplemented, in selected cases, by molecular-genetic diagnostic evaluation. The most commonly detected types of primary tumor are cancers of the lung, pancreas, liver, and biliary system. For patients with local metastases, surgical resection or radiotherapy with curative intent is usually indicated, sometimes in the framework of a multimodal treatment concept. The median 2-year survival of patients with disseminated CUP is only 20%. For such patients, specific types of systemic therapy are recommended on the basis of the diagnostic characterization of the disease. Immune-modulatory antibodies can be effective, particularly in the treatment of CUP that has been characterized with biomarkers, but should still be considered experimental at present. A combination of conventional and innovative diagnostic methods enables the provision of highly refined therapeutic strategies to patients with CUP who are undergoing treatment in interdisciplinary cancer centers.

  2. Known unknowns: indirect energy effects of information and communication technology

    DOE PAGES

    Horner, Nathaniel C.; Shehabi, Arman; Azevedo, Ines L.

    2016-10-05

    There has been sustained and growing interest in characterizing the net energy impact of information and communication technology (ICT), which results from indirect effects offsetting (or amplifying) the energy directly consumed by ICT equipment. These indirect effects may be either positive or negative, and there is considerable disagreement as to the direction of this sign as well as the effect magnitude. Literature in this area ranges from studies focused on a single service (such as e-commerce versus traditional retail) to macroeconomic studies attempting to characterize the overall impact of ICT. Methods. We review the literature on the indirect energy effectmore » of ICT found via Google Scholar, our own research, and input from other researchers in the field. The various studies are linked to an effect taxonomy, which is synthesized from several different hierarchies present in the literature. References are further grouped according to ICT service (e.g., e-commerce, telework) and summarized by scope, method, and quantitative and qualitative findings. Review results. Uncertainty persists in understanding the net energy effects of ICT. Results of indirect energy effect studies are highly sensitive to scoping decisions and assumptions made by the analyst. Uncertainty increases as the impact scope broadens, due to complex and interconnected effects. However, there is general agreement that ICT has large energy savings potential, but that the realization of this potential is highly dependent on deployment details and user behavior. Discussion. While the overall net effect of ICT is likely to remain unknown, this review suggests several guidelines for improving research quality in this area, including increased data collection, enhancing traditional modeling studies with sensitivity analysis, greater care in scoping, less confidence in characterizing aggregate impacts, more effort on understanding user behavior, and more contextual integration across the

  3. Glory on Venus and selection among the unknown UV absorbers

    NASA Astrophysics Data System (ADS)

    Petrova, Elena V.

    2018-05-01

    The comparison of the phase profiles of glories observed on the cloud top of Venus by the Venus Monitoring Camera (Venus Express) and the light-scattering characteristics of sulfuric acid droplets, containing admixtures with a high refractive index, makes it easier to choose between some candidates for the so-called unknown UV absorber in the Venus clouds. Since among the candidates there are materials wetted and not wetted by sulfuric acid, we analyze whether small submicron particles adhered to or embedded into the 1-μm H2SO4 droplets may actually change the glory pattern normally produced by homogeneous spherical particles and what the conditions are, under which the composite particles formed in heterogeneous nucleation may still produce a glory feature. We have found that one of the most frequently considered candidates, sulfur, can hardly be responsible for the contrasts observed at 0.365 μm on the upper clouds, since it is not wetted by sulfuric acid and submicron sulfur particles, serving as condensation nuclei for sulfuric acid, can only adhere to the H2SO4 droplets rather than be enveloped by them. Such droplets decorated by sulfur blobs substantially distort the glory feature characteristic of the scattering by spherical particles or even smooth it at all, while a glory pattern is practically always seen in the images of Venus taken at small phase angles. At the same time, the grains of the other UV absorbers that can be embedded in H2SO4 droplets, e.g., the widely discussed ferric chloride, pose no problem in terms of interpretation of the observations of glory.

  4. Data Series Subtraction with Unknown and Unmodeled Background Noise

    NASA Technical Reports Server (NTRS)

    Vitale, Stefano; Congedo, Giuseppe; Dolesi, Rita; Ferroni, Valerio; Hueller, Mauro; Vetrugno, Daniele; Weber, William Joseph; Audley, Heather; Danzmann, Karsten; Diepholz, Ingo; hide

    2014-01-01

    LISA Pathfinder (LPF), the precursor mission to a gravitational wave observatory of the European Space Agency, will measure the degree to which two test masses can be put into free fall, aiming to demonstrate a suppression of disturbance forces corresponding to a residual relative acceleration with a power spectral density (PSD) below (30 fm/sq s/Hz)(sup 2) around 1 mHz. In LPF data analysis, the disturbance forces are obtained as the difference between the acceleration data and a linear combination of other measured data series. In many circumstances, the coefficients for this linear combination are obtained by fitting these data series to the acceleration, and the disturbance forces appear then as the data series of the residuals of the fit. Thus the background noise or, more precisely, its PSD, whose knowledge is needed to build up the likelihood function in ordinary maximum likelihood fitting, is here unknown, and its estimate constitutes instead one of the goals of the fit. In this paper we present a fitting method that does not require the knowledge of the PSD of the background noise. The method is based on the analytical marginalization of the posterior parameter probability density with respect to the background noise PSD, and returns an estimate both for the fitting parameters and for the PSD. We show that both these estimates are unbiased, and that, when using averaged Welchs periodograms for the residuals, the estimate of the PSD is consistent, as its error tends to zero with the inverse square root of the number of averaged periodograms. Additionally, we find that the method is equivalent to some implementations of iteratively reweighted least-squares fitting. We have tested the method both on simulated data of known PSD and on data from several experiments performed with the LISA Pathfinder end-to-end mission simulator.

  5. Known unknowns: indirect energy effects of information and communication technology

    SciTech Connect

    Horner, Nathaniel C.; Shehabi, Arman; Azevedo, Ines L.

    There has been sustained and growing interest in characterizing the net energy impact of information and communication technology (ICT), which results from indirect effects offsetting (or amplifying) the energy directly consumed by ICT equipment. These indirect effects may be either positive or negative, and there is considerable disagreement as to the direction of this sign as well as the effect magnitude. Literature in this area ranges from studies focused on a single service (such as e-commerce versus traditional retail) to macroeconomic studies attempting to characterize the overall impact of ICT. Methods. We review the literature on the indirect energy effectmore » of ICT found via Google Scholar, our own research, and input from other researchers in the field. The various studies are linked to an effect taxonomy, which is synthesized from several different hierarchies present in the literature. References are further grouped according to ICT service (e.g., e-commerce, telework) and summarized by scope, method, and quantitative and qualitative findings. Review results. Uncertainty persists in understanding the net energy effects of ICT. Results of indirect energy effect studies are highly sensitive to scoping decisions and assumptions made by the analyst. Uncertainty increases as the impact scope broadens, due to complex and interconnected effects. However, there is general agreement that ICT has large energy savings potential, but that the realization of this potential is highly dependent on deployment details and user behavior. Discussion. While the overall net effect of ICT is likely to remain unknown, this review suggests several guidelines for improving research quality in this area, including increased data collection, enhancing traditional modeling studies with sensitivity analysis, greater care in scoping, less confidence in characterizing aggregate impacts, more effort on understanding user behavior, and more contextual integration across the

  6. Known unknowns: indirect energy effects of information and communication technology

    NASA Astrophysics Data System (ADS)

    Horner, Nathaniel C.; Shehabi, Arman; Azevedo, Inês L.

    2016-10-01

    Background. There has been sustained and growing interest in characterizing the net energy impact of information and communication technology (ICT), which results from indirect effects offsetting (or amplifying) the energy directly consumed by ICT equipment. These indirect effects may be either positive or negative, and there is considerable disagreement as to the direction of this sign as well as the effect magnitude. Literature in this area ranges from studies focused on a single service (such as e-commerce versus traditional retail) to macroeconomic studies attempting to characterize the overall impact of ICT. Methods. We review the literature on the indirect energy effect of ICT found via Google Scholar, our own research, and input from other researchers in the field. The various studies are linked to an effect taxonomy, which is synthesized from several different hierarchies present in the literature. References are further grouped according to ICT service (e.g., e-commerce, telework) and summarized by scope, method, and quantitative and qualitative findings. Review results. Uncertainty persists in understanding the net energy effects of ICT. Results of indirect energy effect studies are highly sensitive to scoping decisions and assumptions made by the analyst. Uncertainty increases as the impact scope broadens, due to complex and interconnected effects. However, there is general agreement that ICT has large energy savings potential, but that the realization of this potential is highly dependent on deployment details and user behavior. Discussion. While the overall net effect of ICT is likely to remain unknown, this review suggests several guidelines for improving research quality in this area, including increased data collection, enhancing traditional modeling studies with sensitivity analysis, greater care in scoping, less confidence in characterizing aggregate impacts, more effort on understanding user behavior, and more contextual integration across the

  7. Knowns and unknowns of plasma membrane protein degradation in plants.

    PubMed

    Liu, Chuanliang; Shen, Wenjin; Yang, Chao; Zeng, Lizhang; Gao, Caiji

    2018-07-01

    Plasma membrane (PM) not only creates a physical barrier to enclose the intracellular compartments but also mediates the direct communication between plants and the ever-changing environment. A tight control of PM protein homeostasis by selective degradation is thus crucial for proper plant development and plant-environment interactions. Accumulated evidences have shown that a number of plant PM proteins undergo clathrin-dependent or membrane microdomain-associated endocytic routes to vacuole for degradation in a cargo-ubiquitination dependent or independent manner. Besides, several trans-acting determinants involved in the regulation of endocytosis, recycling and multivesicular body-mediated vacuolar sorting have been identified in plants. More interestingly, recent findings have uncovered the participation of selective autophagy in PM protein turnover in plants. Although great progresses have been made to identify the PM proteins that undergo dynamic changes in subcellular localizations and to explore the factors that control the membrane protein trafficking, several questions remain to be answered regarding the molecular mechanisms of PM protein degradation in plants. In this short review article, we briefly summarize recent progress in our understanding of the internalization, sorting and degradation of plant PM proteins. More specifically, we focus on discussing the elusive aspects underlying the pathways of PM protein degradation in plants. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Charting the Unknown: A Hunt in the Dark

    NASA Astrophysics Data System (ADS)

    Mohlabeng, Gopolang Mokoka

    Astrophysical and cosmological observations have pointed strongly to the existence of dark matter in the Universe, yet its nature remains elusive. It may be hidden in a vast unknown parameter space in which exhaustively searching for a signal is not feasible. We are, therefore, compelled to consider a robust program based on a wide range of new theoretical ideas and complementary strategies for detection. The aim of this dissertation is to investigate the phenomenology of diverse dark sectors with the objective of understanding and characterizing dark matter. We do so by exploring dark matter phenomenology under three main frameworks of study: (I) the model dependent approach, (II) model independent approach and (III) considering simplified models. In each framework we focus on unexplored and well motivated dark matter scenarios as well as their prospects of detection at current and future experiments. First, we concentrate on the model dependent method where we consider minimal dark matter in the form of mixed fermionic stable states in a gauge extension of the standard model. In particular, we incorporate the fermion mixings governed by gauge invariant interactions with the heavier degrees of freedom. We find that the manner of mixing has an impact on the detectability of the dark matter at experiments. Pursuing this model dependent direction, we explore a space-time extension of the standard model which houses a vector dark matter candidate. We incorporate boundary terms arising from the topology of the model and find that these control the way dark matter may interact with baryonic matter. Next we investigate the model independent approach in which we examine a non-minimal dark sector in the form of boosted dark matter. In this study, we consider an effective field theory involving two stable fermionic states. We probe the sensitivity of this type of dark matter coming from the galactic center and the center of the Sun, and investigate its detection prospects

  9. Urine biomarkers of kidney injury among adolescents in Nicaragua, a region affected by an epidemic of chronic kidney disease of unknown aetiology

    PubMed Central

    Ramírez-Rubio, Oriana; Amador, Juan José; Kaufman, James S.; Weiner, Daniel E.; Parikh, Chirag R.; Khan, Usman; McClean, Michael D.; Laws, Rebecca L.; López-Pilarte, Damaris; Friedman, David J.; Kupferman, Joseph; Brooks, Daniel R.

    2016-01-01

    Background An epidemic of chronic kidney disease (CKD) of non-traditional aetiology has been recently recognized by health authorities as a public health priority in Central America. Previous studies have identified strenuous manual work, agricultural activities and residence at low altitude as potential risk factors; however, the aetiology remains unknown. Because individuals are frequently diagnosed with CKD in early adulthood, we measured biomarkers of kidney injury among adolescents in different regions of Nicaragua to assess whether kidney damage might be initiated during childhood. Methods Participants include 200 adolescents aged 12–18 years with no prior work history from four different schools in Nicaragua. The location of the school served as a proxy for environmental exposures and geographic locations were selected to represent a range of factors that have been associated with CKD in adults (e.g. altitude, primary industry and CKD mortality rates). Questionnaires, urine dipsticks and kidney injury biomarkers [interleukin-18, N-acetyl-d-glucosaminidase (NAG), neutrophil gelatinase-associated lipocalin (NGAL) and albumin–creatinine ratio] were assessed. Biomarker concentrations were compared by school using linear regression models. Results Protein (3.5%) and glucose (1%) in urine measured by dipstick were rare and did not differ by school. Urine biomarkers of tubular kidney damage, particularly NGAL and NAG, showed higher concentrations in those schools and regions within Nicaragua that were defined a priori as having increased CKD risk. Painful urination was a frequent self-reported symptom. Conclusions Although interpretation of these urine biomarkers is limited because of the lack of population reference values, results suggest the possibility of early kidney damage prior to occupational exposures in these adolescents. PMID:26311057

  10. Reaching Into the Unknown: Actions, Goal Hierarchies, and Explorative Agency

    PubMed Central

    Gozli, Davood G.; Dolcini, Nevia

    2018-01-01

    Action is widely characterized as possessing a teleological dimension. The dominant way of describing goal-directed action and agency is in terms of exploitation, i.e., pursuing pre-specified goals using existing strategies. Recent theoretical developments emphasize the place of exploration, i.e., discovering new goals or acquiring new strategies. The exploitation-exploration distinction poses questions with regard to goals and agency: Should exploration, as some authors have suggested, be regarded as acting without a goal? We argue that recognizing the hierarchical nature of goals is crucial in distinguishing the two kinds of activity, because this recognition prevents the claim that exploration is goal-free, while allowing for a homogeneous account of both exploitative and explorative actions. An action typically causes relatively low-level/proximal (i.e., sensorimotor, immediate) and relatively high-level/distal (i.e., in the environment, at a wider timescale) outcomes. In exploitation, one relies on existing associations between low- and high-level states, whereas in exploration one does not have the ability or intention to control high-level/distal states. We argue that explorative action entails the capacity to exercise control within the low-level/proximal states, which enables the pursuit of indeterminate goals at the higher levels of a goal hierarchy, and the possibility of acquiring new goals and reorganization of goal hierarchies. We consider how the dominant models of agency might accommodate this capacity for explorative action. PMID:29563888

  11. The knowns and unknowns of human milk banking.

    PubMed

    Simmer, Karen

    2011-01-01

    The provision of donor human milk instead of formula is an important contribution to the nutrition and protection from infections for preterm infants. Systematic reviews suggest a lower risk of necrotizing enterocolitis with pasteurized donor human milk (PDHM) as opposed to artificial formula, although evidence supporting PDHM use from randomized control trials is limited. Human milk banks (HMBs) must have a risk management system to maintain a safe product especially as many operate in an unregulated environment. To ensure safety, the HMB in Australia has committed to meet the appropriate standards recommended in the Code of Good Manufacturing Practices (Blood and Tissues) and models risk management during processing on Codex HACCP (Hazard Analysis Critical Control Point) requirements. There is scope to continually reevaluate the screening of donors and quality standards recommended during HMB. This will be most effective if strong networks of HMBs are developed with regional reference laboratories to encourage compliance with safety guidelines. Further research and development is needed to refine technology for treating donor milk such as thermal ultrasound and ultraviolet light, aimed at the retention of full bioactivity. HMB networks will facilitate collection of evidence for refining HMB practice which should translate to improved outcomes for preterm and sick infants. Cost effectiveness is most likely when HMBs are associated with large neonatal intensive care units. Copyright © 2011 S. Karger AG, Basel.

  12. Some Unknown Pages of the Living Organisms' First Orbital Flight

    NASA Astrophysics Data System (ADS)

    Malashenkov, D. C.

    2002-01-01

    were developed. 10 dogs successfully finished complete course of training and experiments were also selected. Three dogs were selected for flight: Albina, Layka and Mushka. Albina flied on a rockets twice before, and it was decided to continue observation over it. The decision therefore was accepted to send Layka in flight. Albina was a double, and Mushka was a "technological dog" - all the equipment and life-support systems of the satellite were tested on it. The flight of the second artificial satellite of the Earth with Layka dog was held on November 3, 1957. All resources of life- support system were designed for 7 days of flight. The analysis of the data of the parameters of the environment of the cabin has shown, that the content of oxygen during flight was sufficient. The fact, that pressure in the cabin was not reduced, proved its reliable tightness. It was very important, as the satellite passed through areas of meteoric flows. Normalization of parameters of breath and blood circulation of Layka during orbital flight has allowed to make a conclusion, that the long weightlessness does not cause essential changes in a status of animal organisms. During flight the gradual increase of temperature and humidity in the cabin was registered via telemetric channels. Approximately in 5 - 7 hours of flight there was a failure of telemetry system. It was not possible to detect a status of the dog since the fourth circuit. During the ground simulation of this flight's conditions, the conclusion was made, that Layka should be lost because of overheating on 3d or 4-th circuit of flight. It turned out that it was practically impossible to create a reliable temperature control system in such limited time constraints. The biological research, which has been carried out on second satellite, has complimented a material obtained during vertical launches of rockets. The received experimental data have confirmed the initial assumption, that the conditions of space flight will not

  13. Assembly of Robust Bacterial Microcompartment Shells Using Building Blocks from an Organelle of Unknown Function

    SciTech Connect

    Lassila, JK; Bernstein, SL; Kinney, JN

    Bacterial microconnpartnnents (BMCs) sequester enzymes from the cytoplasmic environment by encapsulation inside a selectively permeable protein shell. Bioinformatic analyses indicate that many bacteria encode BMC clusters of unknown function and with diverse combinations of shell proteins. The genome of the halophilic myxobacterium Haliangium ochraceum encodes one of the most atypical sets of shell proteins in terms of composition and primary structure. We found that microconnpartnnent shells could be purified in high yield when all seven H. ochraceum BMC shell genes were expressed from a synthetic operon in Escherichia coll. These shells differ substantially from previously isolated shell systems in thatmore » they are considerably smaller and more homogeneous, with measured diameters of 39 2 nm. The size and nearly uniform geometry allowed the development of a structural model for the shells composed of 260 hexagonal units and 13 hexagons per icosahedral face. We found that new proteins could be recruited to the shells by fusion to a predicted targeting peptide sequence, setting the stage for the use of these remarkably homogeneous shells for applications such as three-dimensional scaffolding and the construction of synthetic BMCs. Our results demonstrate the value of selecting from the diversity of BMC shell building blocks found in genomic sequence data for the construction of novel compartments. (C) 2014 Elsevier Ltd. All rights reserved.« less

  14. Lonely GPFUTV-the movement of water under the action of unknown vacuum

    NASA Astrophysics Data System (ADS)

    Lin, Weiyi

    2013-11-01

    In this paper, firstly, the experiment on the flow resistance of the aerated pipe flow is introduced. The experimental research on comparison between different volumes of air entrained is presented. Secondly, the characteristics of gravity pipe flow under the action of Torricelli's vacuum, shortly called as GPFUTV are dissertated, including creative and functional design, fundamental principle, etc. Under the joint action of an unknown vacuum energy and the formation of non-aerated flow the water flow is full-pipe and continuous, high-speed and non-rotational as distinguished from turbulent flow. Thirdly, an appeal in relation to the experimental research, the applied studies and basic theory research is given. For instance, experimental study of Torricelli's experiment phenomenon in the vacuum environment, applied study of the potential for GPFUTV to be developed for deep seawater suction technology and lifting technology for deep ocean mining, theoretical study of flow stability and flow resistance under GPFUTV condition, etc. At last, the famous GPFUTV project is illustrated. 12 years of rigorous and independent survey research.

  15. Direct Position Determination of Unknown Signals in the Presence of Multipath Propagation.

    PubMed

    Du, Jianping; Wang, Ding; Yu, Wanting; Yu, Hongyi

    2018-03-17

    A novel geolocation architecture, termed "Multiple Transponders and Multiple Receivers for Multiple Emitters Positioning System (MTRE)" is proposed in this paper. Existing Direct Position Determination (DPD) methods take advantage of a rather simple channel assumption (line of sight channels with complex path attenuations) and a simplified MUltiple SIgnal Classification (MUSIC) algorithm cost function to avoid the high dimension searching. We point out that the simplified assumption and cost function reduce the positioning accuracy because of the singularity of the array manifold in a multi-path environment. We present a DPD model for unknown signals in the presence of Multi-path Propagation (MP-DPD) in this paper. MP-DPD adds non-negative real path attenuation constraints to avoid the mistake caused by the singularity of the array manifold. The Multi-path Propagation MUSIC (MP-MUSIC) method and the Active Set Algorithm (ASA) are designed to reduce the dimension of searching. A Multi-path Propagation Maximum Likelihood (MP-ML) method is proposed in addition to overcome the limitation of MP-MUSIC in the sense of a time-sensitive application. An iterative algorithm and an approach of initial value setting are given to make the MP-ML time consumption acceptable. Numerical results validate the performances improvement of MP-MUSIC and MP-ML. A closed form of the Cramér-Rao Lower Bound (CRLB) is derived as a benchmark to evaluate the performances of MP-MUSIC and MP-ML.

  16. Off-Policy Actor-Critic Structure for Optimal Control of Unknown Systems With Disturbances.

    PubMed

    Song, Ruizhuo; Lewis, Frank L; Wei, Qinglai; Zhang, Huaguang

    2016-05-01

    An optimal control method is developed for unknown continuous-time systems with unknown disturbances in this paper. The integral reinforcement learning (IRL) algorithm is presented to obtain the iterative control. Off-policy learning is used to allow the dynamics to be completely unknown. Neural networks are used to construct critic and action networks. It is shown that if there are unknown disturbances, off-policy IRL may not converge or may be biased. For reducing the influence of unknown disturbances, a disturbances compensation controller is added. It is proven that the weight errors are uniformly ultimately bounded based on Lyapunov techniques. Convergence of the Hamiltonian function is also proven. The simulation study demonstrates the effectiveness of the proposed optimal control method for unknown systems with disturbances.

  17. A Novel Method of Combining Blood Oxygenation and Blood Flow Sensitive Magnetic Resonance Imaging Techniques to Measure the Cerebral Blood Flow and Oxygen Metabolism Responses to an Unknown Neural Stimulus

    PubMed Central

    Simon, Aaron B.; Griffeth, Valerie E. M.; Wong, Eric C.; Buxton, Richard B.

    2013-01-01

    Simultaneous implementation of magnetic resonance imaging methods for Arterial Spin Labeling (ASL) and Blood Oxygenation Level Dependent (BOLD) imaging makes it possible to quantitatively measure the changes in cerebral blood flow (CBF) and cerebral oxygen metabolism (CMRO2) that occur in response to neural stimuli. To date, however, the range of neural stimuli amenable to quantitative analysis is limited to those that may be presented in a simple block or event related design such that measurements may be repeated and averaged to improve precision. Here we examined the feasibility of using the relationship between cerebral blood flow and the BOLD signal to improve dynamic estimates of blood flow fluctuations as well as to estimate metabolic-hemodynamic coupling under conditions where a stimulus pattern is unknown. We found that by combining the information contained in simultaneously acquired BOLD and ASL signals through a method we term BOLD Constrained Perfusion (BCP) estimation, we could significantly improve the precision of our estimates of the hemodynamic response to a visual stimulus and, under the conditions of a calibrated BOLD experiment, accurately determine the ratio of the oxygen metabolic response to the hemodynamic response. Importantly we were able to accomplish this without utilizing a priori knowledge of the temporal nature of the neural stimulus, suggesting that BOLD Constrained Perfusion estimation may make it feasible to quantitatively study the cerebral metabolic and hemodynamic responses to more natural stimuli that cannot be easily repeated or averaged. PMID:23382977

  18. Clinical characteristics of children with mental retardation of unknown etiology in Korea.

    PubMed Central

    Yim, S. Y.; Lee, I. Y.

    1999-01-01

    The purpose of this study was to investigate the clinical characteristics of children with mental retardation (MR) of unknown etiology for early recognition and intervention. In this study, we defined children with MR of unknown etiology as those without clear etiologies for MR despite extensive evaluation and were not associated with pathological behavioral problems such as pervasive developmental disorders and attention-deficit/hyperactivity disorder. The clinical characteristics of children with MR of unknown etiology were as follows. 1) MR of unknown etiology was 48.8% of all MR. 2) MR of unknown etiology was more common in males. 3) Delayed language development was a leading factor that made the parents of children with MR of unknown etiology seek help from physicians. However, most of the children with MR of unknown etiology showed a relatively uniform delay in several areas of development. 4) Most children with MR of unknown etiology were delayed walkers. 5) Most children with MR of unknown etiology were mild cases. PMID:10331556

  19. Contemporary group estimates adjusted for climatic effects provide a finer definition of the unknown environmental challenges experienced by growing pigs.

    PubMed

    Guy, S Z Y; Li, L; Thomson, P C; Hermesch, S

    2017-12-01

    Environmental descriptors derived from mean performances of contemporary groups (CGs) are assumed to capture any known and unknown environmental challenges. The objective of this paper was to obtain a finer definition of the unknown challenges, by adjusting CG estimates for the known climatic effects of monthly maximum air temperature (MaxT), minimum air temperature (MinT) and monthly rainfall (Rain). As the unknown component could include infection challenges, these refined descriptors may help to better model varying responses of sire progeny to environmental infection challenges for the definition of disease resilience. Data were recorded from 1999 to 2013 at a piggery in south-east Queensland, Australia (n = 31,230). Firstly, CG estimates of average daily gain (ADG) and backfat (BF) were adjusted for MaxT, MinT and Rain, which were fitted as splines. In the models used to derive CG estimates for ADG, MaxT and MinT were significant variables. The models that contained these significant climatic variables had CG estimates with a lower variance compared to models without significant climatic variables. Variance component estimates were similar across all models, suggesting that these significant climatic variables accounted for some known environmental variation captured in CG estimates. No climatic variables were significant in the models used to derive the CG estimates for BF. These CG estimates were used to categorize environments. There was no observable sire by environment interaction (Sire×E) for ADG when using the environmental descriptors based on CG estimates on BF. For the environmental descriptors based on CG estimates of ADG, there was significant Sire×E only when MinT was included in the model (p = .01). Therefore, this new definition of the environment, preadjusted by MinT, increased the ability to detect Sire×E. While the unknown challenges captured in refined CG estimates need verification for infection challenges, this may provide a

  20. Race Unknown

    ERIC Educational Resources Information Center

    Gray, Katti

    2011-01-01

    Bryan Lee, a senior at the University of California, Irvine, has noticed that some of his classmates adamantly declare their multiracial heritage while others choose not to identify themselves as being any particular ethnicity. The half-Korean, half-White biomedical engineering major is co-president of the university's Mixed Students Organization…

  1. Destination Unknown.

    ERIC Educational Resources Information Center

    Brownstein, Andrew; Hoover, Eric

    2001-01-01

    Explores how, for college students, the events of September 11, 2001, have changed everything; the new directions they have taken vary as much as they do. Presents profiles of several students with differing perspectives. (EV)

  2. Unknown genius

    NASA Astrophysics Data System (ADS)

    Weaire, Denis; Donegan, John F.; Florides, Petros S.

    2012-12-01

    A visionary who saw far ahead of his contemporaries, Edward Hutchinson Synge has been largely overlooked by the academic world, from which he worked in isolation before he was confined to a mental hospital at the age of 46. Denis Weaire, John F Donegan and Petros S Florides uncover his remarkable story.

  3. Optimal Strategy for Integrated Dynamic Inventory Control and Supplier Selection in Unknown Environment via Stochastic Dynamic Programming

    NASA Astrophysics Data System (ADS)

    Sutrisno; Widowati; Solikhin

    2016-06-01

    In this paper, we propose a mathematical model in stochastic dynamic optimization form to determine the optimal strategy for an integrated single product inventory control problem and supplier selection problem where the demand and purchasing cost parameters are random. For each time period, by using the proposed model, we decide the optimal supplier and calculate the optimal product volume purchased from the optimal supplier so that the inventory level will be located at some point as close as possible to the reference point with minimal cost. We use stochastic dynamic programming to solve this problem and give several numerical experiments to evaluate the model. From the results, for each time period, the proposed model was generated the optimal supplier and the inventory level was tracked the reference point well.

  4. 48 CFR 52.222-49 - Service Contract Act-Place of Performance Unknown.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Service Contract Act-Place... Provisions and Clauses 52.222-49 Service Contract Act—Place of Performance Unknown. As prescribed in 22.1006(f), insert the following clause: Service Contract Act—Place of Performance Unknown (MAY 1989) (a...

  5. 39 CFR 946.4 - Disposition of property of unknown owners.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... DISPOSITION OF STOLEN MAIL MATTER AND PROPERTY ACQUIRED BY THE POSTAL INSPECTION SERVICE FOR USE AS EVIDENCE § 946.4 Disposition of property of unknown owners. (a) Where no apparent owner of property subject to... 39 Postal Service 1 2010-07-01 2010-07-01 false Disposition of property of unknown owners. 946.4...

  6. 39 CFR 946.4 - Disposition of property of unknown owners.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... DISPOSITION OF STOLEN MAIL MATTER AND PROPERTY ACQUIRED BY THE POSTAL INSPECTION SERVICE FOR USE AS EVIDENCE § 946.4 Disposition of property of unknown owners. (a) Where no apparent owner of property subject to... 39 Postal Service 1 2011-07-01 2011-07-01 false Disposition of property of unknown owners. 946.4...

  7. A Simulation Study Comparison of Bayesian Estimation with Conventional Methods for Estimating Unknown Change Points

    ERIC Educational Resources Information Center

    Wang, Lijuan; McArdle, John J.

    2008-01-01

    The main purpose of this research is to evaluate the performance of a Bayesian approach for estimating unknown change points using Monte Carlo simulations. The univariate and bivariate unknown change point mixed models were presented and the basic idea of the Bayesian approach for estimating the models was discussed. The performance of Bayesian…

  8. Classification and authentication of unknown water samples using machine learning algorithms.

    PubMed

    Kundu, Palash K; Panchariya, P C; Kundu, Madhusree

    2011-07-01

    This paper proposes the development of water sample classification and authentication, in real life which is based on machine learning algorithms. The proposed techniques used experimental measurements from a pulse voltametry method which is based on an electronic tongue (E-tongue) instrumentation system with silver and platinum electrodes. E-tongue include arrays of solid state ion sensors, transducers even of different types, data collectors and data analysis tools, all oriented to the classification of liquid samples and authentication of unknown liquid samples. The time series signal and the corresponding raw data represent the measurement from a multi-sensor system. The E-tongue system, implemented in a laboratory environment for 6 numbers of different ISI (Bureau of Indian standard) certified water samples (Aquafina, Bisleri, Kingfisher, Oasis, Dolphin, and McDowell) was the data source for developing two types of machine learning algorithms like classification and regression. A water data set consisting of 6 numbers of sample classes containing 4402 numbers of features were considered. A PCA (principal component analysis) based classification and authentication tool was developed in this study as the machine learning component of the E-tongue system. A proposed partial least squares (PLS) based classifier, which was dedicated as well; to authenticate a specific category of water sample evolved out as an integral part of the E-tongue instrumentation system. The developed PCA and PLS based E-tongue system emancipated an overall encouraging authentication percentage accuracy with their excellent performances for the aforesaid categories of water samples. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

  9. Direct Position Determination of Unknown Signals in the Presence of Multipath Propagation

    PubMed Central

    Yu, Hongyi

    2018-01-01

    A novel geolocation architecture, termed “Multiple Transponders and Multiple Receivers for Multiple Emitters Positioning System (MTRE)” is proposed in this paper. Existing Direct Position Determination (DPD) methods take advantage of a rather simple channel assumption (line of sight channels with complex path attenuations) and a simplified MUltiple SIgnal Classification (MUSIC) algorithm cost function to avoid the high dimension searching. We point out that the simplified assumption and cost function reduce the positioning accuracy because of the singularity of the array manifold in a multi-path environment. We present a DPD model for unknown signals in the presence of Multi-path Propagation (MP-DPD) in this paper. MP-DPD adds non-negative real path attenuation constraints to avoid the mistake caused by the singularity of the array manifold. The Multi-path Propagation MUSIC (MP-MUSIC) method and the Active Set Algorithm (ASA) are designed to reduce the dimension of searching. A Multi-path Propagation Maximum Likelihood (MP-ML) method is proposed in addition to overcome the limitation of MP-MUSIC in the sense of a time-sensitive application. An iterative algorithm and an approach of initial value setting are given to make the MP-ML time consumption acceptable. Numerical results validate the performances improvement of MP-MUSIC and MP-ML. A closed form of the Cramér–Rao Lower Bound (CRLB) is derived as a benchmark to evaluate the performances of MP-MUSIC and MP-ML. PMID:29562601

  10. The dilemma in prioritizing chemicals for environmental analysis: known versus unknown hazards.

    PubMed

    Anna, Sobek; Sofia, Bejgarn; Christina, Rudén; Magnus, Breitholtz

    2016-08-10

    A major challenge for society is to manage the risks posed by the many chemicals continuously emitted to the environment. All chemicals in production and use cannot be monitored and science-based strategies for prioritization are essential. In this study we review available data to investigate which substances are included in environmental monitoring programs and published research studies reporting analyses of chemicals in Baltic Sea fish between 2000 and 2012. Our aim is to contribute to the discussion of priority settings in environmental chemical monitoring and research, which is closely linked to chemical management. In total, 105 different substances or substance groups were analyzed in Baltic Sea fish. Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) were the most studied substances or substance groups. The majority, 87%, of all analyses comprised 20% of the substances or substance groups, whereas 46 substance groups (44%) were analyzed only once. Almost three quarters of all analyses regarded a POP-substance (persistent organic pollutant). These results demonstrate that the majority of analyses on environmental contaminants in Baltic Sea fish concern a small number of already regulated chemicals. Legacy pollutants such as POPs pose a high risk to the Baltic Sea due to their hazardous properties. Yet, there may be a risk that prioritizations for chemical analyses are biased based on the knowns of the past. Such biases may lead to society failing in identifying risks posed by yet unknown hazardous chemicals. Alternative and complementary ways to identify priority chemicals are needed. More transparent communication between risk assessments performed as part of the risk assessment process within REACH and monitoring programs, and information on chemicals contained in consumer articles, would offer ways to identify chemicals for environmental analysis.

  11. Magnetic resonance appearance of monoclonal gammopathies of unknown significance and multiple myeloma. The GRI Study Group.

    PubMed

    Bellaïche, L; Laredo, J D; Lioté, F; Koeger, A C; Hamze, B; Ziza, J M; Pertuiset, E; Bardin, T; Tubiana, J M

    1997-11-01

    A prospective multicenter study. To evaluate the use of magnetic resonance imaging, in the differentiation between monoclonal gammopathies of unknown significance and multiple myeloma. Although multiple myeloma has been studied extensively with magnetic resonance imaging, to the authors' knowledge, no study has evaluated the clinical interest of magnetic resonance imaging in the differentiation between monoclonal gammopathies of unknown significance and multiple myeloma. The magnetic resonance examinations of the thoracolumbar spine in 24 patients with newly diagnosed monoclonal gammopathies of unknown significance were compared with those performed in 44 patients with newly diagnosed nontreated multiple myeloma. All findings on magnetic resonance examination performed in patients with monoclonal gammopathies of unknown significance were normal, whereas findings on 38 (86%) of the 44 magnetic resonance examinations performed in patients with multiple myeloma were abnormal. Magnetic resonance imaging can be considered as an additional diagnostic tool in differentiating between monoclonal gammopathies of unknown significance and multiple myeloma, which may be helpful when routine criteria are not sufficient. An abnormal finding on magnetic resonance examination in a patient with monoclonal gammopathies of unknown significance should suggest the diagnosis of multiple myeloma after other causes of marrow signal abnormalities are excluded. Magnetic resonance imaging also may be proposed in the long-term follow-up of monoclonal gammopathies of unknown significance when a new biologic or clinical event suggests the diagnosis of malignant monoclonal gammopathy.

  12. Impact of Accurate 30-Day Status on Operative Mortality: Wanted Dead or Alive, Not Unknown.

    PubMed

    Ring, W Steves; Edgerton, James R; Herbert, Morley; Prince, Syma; Knoff, Cathy; Jenkins, Kristin M; Jessen, Michael E; Hamman, Baron L

    2017-12-01

    Risk-adjusted operative mortality is the most important quality metric in cardiac surgery for determining The Society of Thoracic Surgeons (STS) Composite Score for star ratings. Accurate 30-day status is required to determine STS operative mortality. The goal of this study was to determine the effect of unknown or missing 30-day status on risk-adjusted operative mortality in a regional STS Adult Cardiac Surgery Database cooperative and demonstrate the ability to correct these deficiencies by matching with an administrative database. STS Adult Cardiac Surgery Database data were submitted by 27 hospitals from five hospital systems to the Texas Quality Initiative (TQI), a regional quality collaborative. TQI data were matched with a regional hospital claims database to resolve unknown 30-day status. The risk-adjusted operative mortality observed-to-expected (O/E) ratio was determined before and after matching to determine the effect of unknown status on the operative mortality O/E. TQI found an excessive (22%) unknown 30-day status for STS isolated coronary artery bypass grafting cases. Matching the TQI data to the administrative claims database reduced the unknowns to 7%. The STS process of imputing unknown 30-day status as alive underestimates the true operative mortality O/E (1.27 before vs 1.30 after match), while excluding unknowns overestimates the operative mortality O/E (1.57 before vs 1.37 after match) for isolated coronary artery bypass grafting. The current STS algorithm of imputing unknown 30-day status as alive and a strategy of excluding cases with unknown 30-day status both result in erroneous calculation of operative mortality and operative mortality O/E. However, external validation by matching with an administrative database can improve the accuracy of clinical databases such as the STS Adult Cardiac Surgery Database. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  13. Discrete-time switching periodic adaptive control for time-varying parameters with unknown periodicity

    NASA Astrophysics Data System (ADS)

    Yu, Miao; Huang, Deqing; Yang, Wanqiu

    2018-06-01

    In this paper, we address the problem of unknown periodicity for a class of discrete-time nonlinear parametric systems without assuming any growth conditions on the nonlinearities. The unknown periodicity hides in the parametric uncertainties, which is difficult to estimate with existing techniques. By incorporating a logic-based switching mechanism, we identify the period and bound of unknown parameter simultaneously. Lyapunov-based analysis is given to demonstrate that a finite number of switchings can guarantee the asymptotic tracking for the nonlinear parametric systems. The simulation result also shows the efficacy of the proposed switching periodic adaptive control approach.

  14. Sudden suffocation with cancer of unknown primary: a case report and review of diagnostic approach.

    PubMed

    Tehrani, Omid S; Ahmad, Omar; Vypritskaya, Ekaterina; Chen, Emily; Hasan, Saba

    2012-10-01

    A case of a 31-year-old woman with sudden respiratory distress is presented. Preliminary evaluations and imaging studies did not reveal the underlying cause. Workup during hospital stay showed advanced metastatic cancer of unknown primary origin. This is an unusual presentation of cancer of an unknown primary involving the thyroid with sudden suffocation. It suggests that malignancies involving the thyroid gland should be considered in patients with abrupt onset of respiratory distress. Also, this case shows the application of fine needle aspiration in diffuse thyroid enlargements mimicking thyroiditis without nodules. Diagnostic approach to cancer of unknown primary origin (CUP) is reviewed in further detail.

  15. Matrix- and tensor-based recommender systems for the discovery of currently unknown inorganic compounds

    NASA Astrophysics Data System (ADS)

    Seko, Atsuto; Hayashi, Hiroyuki; Kashima, Hisashi; Tanaka, Isao

    2018-01-01

    Chemically relevant compositions (CRCs) and atomic arrangements of inorganic compounds have been collected as inorganic crystal structure databases. Machine learning is a unique approach to search for currently unknown CRCs from vast candidates. Herein we propose matrix- and tensor-based recommender system approaches to predict currently unknown CRCs from database entries of CRCs. Firstly, the performance of the recommender system approaches to discover currently unknown CRCs is examined. A Tucker decomposition recommender system shows the best discovery rate of CRCs as the majority of the top 100 recommended ternary and quaternary compositions correspond to CRCs. Secondly, systematic density functional theory (DFT) calculations are performed to investigate the phase stability of the recommended compositions. The phase stability of the 27 compositions reveals that 23 currently unknown compounds are newly found to be stable. These results indicate that the recommender system has great potential to accelerate the discovery of new compounds.

  16. Rendezvous with connectivity preservation for multi-robot systems with an unknown leader

    NASA Astrophysics Data System (ADS)

    Dong, Yi

    2018-02-01

    This paper studies the leader-following rendezvous problem with connectivity preservation for multi-agent systems composed of uncertain multi-robot systems subject to external disturbances and an unknown leader, both of which are generated by a so-called exosystem with parametric uncertainty. By combining internal model design, potential function technique and adaptive control, two distributed control strategies are proposed to maintain the connectivity of the communication network, to achieve the asymptotic tracking of all the followers to the output of the unknown leader system, as well as to reject unknown external disturbances. It is also worth to mention that the uncertain parameters in the multi-robot systems and exosystem are further allowed to belong to unknown and unbounded sets when applying the second fully distributed control law containing a dynamic gain inspired by high-gain adaptive control or self-tuning regulator.

  17. Application of non-destructive testing to evaluate unknown foundations for Pennsylvania bridges.

    DOT National Transportation Integrated Search

    2013-08-01

    Unknown bridge foundations present a unique challenge to Departments of Transportation (DOT) across the country since : foundation characteristics are a necessary input to assess scour vulnerability and to develop appropriate scour countermeasures. :...

  18. 18. AERIAL VIEW OF PRISON COMPLEX, CIRCA 1930s Photographer unknown; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. AERIAL VIEW OF PRISON COMPLEX, CIRCA 1930s Photographer unknown; National Archives and Records Administration photograph No. 18-AN-31716. - New Jersey State Prison, Second & Federal Streets, Trenton, Mercer County, NJ

  19. Decentralised output feedback control of Markovian jump interconnected systems with unknown interconnections

    NASA Astrophysics Data System (ADS)

    Li, Li-Wei; Yang, Guang-Hong

    2017-07-01

    The problem of decentralised output feedback control is addressed for Markovian jump interconnected systems with unknown interconnections and general transition rates (TRs) allowed to be unknown or known with uncertainties. A class of decentralised dynamic output feedback controllers are constructed, and a cyclic-small-gain condition is exploited to dispose the unknown interconnections so that the resultant closed-loop system is stochastically stable and satisfies an H∞ performance. With slack matrices to cope with the nonlinearities incurred by unknown and uncertain TRs in control synthesis, a novel controller design condition is developed in linear matrix inequality formalism. Compared with the existing works, the proposed approach leads to less conservatism. Finally, two examples are used to illustrate the effectiveness of the new results.

  20. Unknown sequence amplification: Application to in vitro genome walking in Chlamydia trachomatis L2

    SciTech Connect

    Copley, C.G.; Boot, C.; Bundell, K.

    1991-01-01

    A recently described technique, Chemical Genetics' unknown sequence amplification method, which requires only one specific oligonucleotide, has broadened the applicability of the polymerase chain reaction to DNA of unknown sequence. The authors have adapted this technique to the study of the genome of Chlamydia trachomatis, an obligate intracellular bacterium, and describe modifications that significantly improve the utility of this approach. These techniques allow for rapid genomic analysis entirely in vitro, using DNA of limited quantity of purity.