Science.gov

Sample records for aided target recognition

  1. Tracker-aided adaptive multi-frame recognition of a specific target

    NASA Astrophysics Data System (ADS)

    Mahalanobis, Abhijit

    2016-05-01

    We consider the problem of recognizing a particular target of interest (i.e. the "correct" target) while rejecting other targets and background clutter. In such instances, the probability of recognizing the correct target (PCT) is a suitable metric for assessing the performance of the target recognition algorithm. We present a definition for PCT and illustrate how it differs from conventional metrics for target recognition by means of an example. It is further shown that an adaptive target recognition algorithm, which relies on track position to obtain multiple looks at the target, can significantly improve PCT while reducing the track uncertainty.

  2. User acceptance of intelligent avionics: A study of automatic-aided target recognition

    NASA Technical Reports Server (NTRS)

    Becker, Curtis A.; Hayes, Brian C.; Gorman, Patrick C.

    1991-01-01

    User acceptance of new support systems typically was evaluated after the systems were specified, designed, and built. The current study attempts to assess user acceptance of an Automatic-Aided Target Recognition (ATR) system using an emulation of such a proposed system. The detection accuracy and false alarm level of the ATR system were varied systematically, and subjects rated the tactical value of systems exhibiting different performance levels. Both detection accuracy and false alarm level affected the subjects' ratings. The data from two experiments suggest a cut-off point in ATR performance below which the subjects saw little tactical value in the system. An ATR system seems to have obvious tactical value only if it functions at a correct detection rate of 0.7 or better with a false alarm level of 0.167 false alarms per square degree or fewer.

  3. Aided targeting system simulation evaluation

    NASA Technical Reports Server (NTRS)

    Demaio, Joe; Becker, Curtis

    1994-01-01

    Simulation research was conducted at the Crew Station Research and Development Facility on the effectiveness and ease of use of three targeting systems. A manual system required the aviator to scan a target array area with a simulated second generation forward looking infrared (FLIR) sensor, locate and categorize targets, and construct a target hand-off list. The interface between the aviator and the system was like that of an advanced scout helicopter (manual mode). Two aided systems detected and categorized targets automatically. One system used only the FLIR sensor and the second used FLIR fused with Longbow radar. The interface for both was like that of an advanced scout helicopter aided mode. Exposure time while performing the task was reduced substantially with the aided systems, with no loss of target hand-off list accuracy. The fused sensor system showed lower time to construct the target hand-off list and a slightly lower false alarm rate than the other systems. A number of issues regarding system sensitivity and criterion, and operator interface design are discussed.

  4. Target Recognition Using Neural Networks for Model Deformation Measurements

    NASA Technical Reports Server (NTRS)

    Ross, Richard W.; Hibler, David L.

    1999-01-01

    Optical measurements provide a non-invasive method for measuring deformation of wind tunnel models. Model deformation systems use targets mounted or painted on the surface of the model to identify known positions, and photogrammetric methods are used to calculate 3-D positions of the targets on the model from digital 2-D images. Under ideal conditions, the reflective targets are placed against a dark background and provide high-contrast images, aiding in target recognition. However, glints of light reflecting from the model surface, or reduced contrast caused by light source or model smoothness constraints, can compromise accurate target determination using current algorithmic methods. This paper describes a technique using a neural network and image processing technologies which increases the reliability of target recognition systems. Unlike algorithmic methods, the neural network can be trained to identify the characteristic patterns that distinguish targets from other objects of similar size and appearance and can adapt to changes in lighting and environmental conditions.

  5. Recognition of Hits in a Target

    NASA Astrophysics Data System (ADS)

    Semerak, Vojtech; Drahansky, Martin

    This paper describes two possible ways of hit recognition in a target. First method is based on frame differencing with use of a stabilization algorithm to eliminate movements of a target. Second method uses flood fill with random seed point definition to find hits in the target scene.

  6. System integration of pattern recognition, adaptive aided, upper limb prostheses

    NASA Technical Reports Server (NTRS)

    Lyman, J.; Freedy, A.; Solomonow, M.

    1975-01-01

    The requirements for successful integration of a computer aided control system for multi degree of freedom artificial arms are discussed. Specifications are established for a system which shares control between a human amputee and an automatic control subsystem. The approach integrates the following subsystems: (1) myoelectric pattern recognition, (2) adaptive computer aiding; (3) local reflex control; (4) prosthetic sensory feedback; and (5) externally energized arm with the functions of prehension, wrist rotation, elbow extension and flexion and humeral rotation.

  7. Extended target recognition in cognitive radar networks.

    PubMed

    Wei, Yimin; Meng, Huadong; Liu, Yimin; Wang, Xiqin

    2010-01-01

    We address the problem of adaptive waveform design for extended target recognition in cognitive radar networks. A closed-loop active target recognition radar system is extended to the case of a centralized cognitive radar network, in which a generalized likelihood ratio (GLR) based sequential hypothesis testing (SHT) framework is employed. Using Doppler velocities measured by multiple radars, the target aspect angle for each radar is calculated. The joint probability of each target hypothesis is then updated using observations from different radar line of sights (LOS). Based on these probabilities, a minimum correlation algorithm is proposed to adaptively design the transmit waveform for each radar in an amplitude fluctuation situation. Simulation results demonstrate performance improvements due to the cognitive radar network and adaptive waveform design. Our minimum correlation algorithm outperforms the eigen-waveform solution and other non-cognitive waveform design approaches.

  8. AID targeting: old mysteries and new challenges.

    PubMed

    Chandra, Vivek; Bortnick, Alexandra; Murre, Cornelis

    2015-09-01

    Activation-induced cytidine deaminase (AID) mediates cytosine deamination and underlies two central processes in antibody diversification: somatic hypermutation and class-switch recombination. AID deamination is not exclusive to immunoglobulin loci; it can instigate DNA lesions in non-immunoglobulin genes and thus stringent checks are in place to constrain and restrict its activity. Recent findings have provided new insights into the mechanisms that target AID activity to specific genomic regions, revealing an involvement for noncoding RNAs associated with polymerase pausing and with enhancer transcription as well as genomic architecture. We review these findings and integrate them into a model for multilevel regulation of AID expression and targeting in immunoglobulin and non-immunoglobulin loci. Within this framework we discuss gaps in understanding, and outline important areas of further research. PMID:26254147

  9. An Introduction to Neural Networks for Hearing Aid Noise Recognition.

    ERIC Educational Resources Information Center

    Kim, Jun W.; Tyler, Richard S.

    1995-01-01

    This article introduces the use of multilayered artificial neural networks in hearing aid noise recognition. It reviews basic principles of neural networks, and offers an example of an application in which a neural network is used to identify the presence or absence of noise in speech. The ability of neural networks to "learn" the characteristics…

  10. Laser range profiling for small target recognition

    NASA Astrophysics Data System (ADS)

    Steinvall, Ove; Tulldahl, Michael

    2016-05-01

    The detection and classification of small surface and airborne targets at long ranges is a growing need for naval security. Long range ID or ID at closer range of small targets has its limitations in imaging due to the demand on very high transverse sensor resolution. It is therefore motivated to look for 1D laser techniques for target ID. These include vibrometry, and laser range profiling. Vibrometry can give good results but is also sensitive to certain vibrating parts on the target being in the field of view. Laser range profiling is attractive because the maximum range can be substantial, especially for a small laser beam width. A range profiler can also be used in a scanning mode to detect targets within a certain sector. The same laser can also be used for active imaging when the target comes closer and is angular resolved. The present paper will show both experimental and simulated results for laser range profiling of small boats out to 6-7 km range and a UAV mockup at close range (1.3 km). We obtained good results with the profiling system both for target detection and recognition. Comparison of experimental and simulated range waveforms based on CAD models of the target support the idea of having a profiling system as a first recognition sensor and thus narrowing the search space for the automatic target recognition based on imaging at close ranges. The naval experiments took place in the Baltic Sea with many other active and passive EO sensors beside the profiling system. Discussion of data fusion between laser profiling and imaging systems will be given. The UAV experiments were made from the rooftop laboratory at FOI.

  11. Protein-targeted corona phase molecular recognition.

    PubMed

    Bisker, Gili; Dong, Juyao; Park, Hoyoung D; Iverson, Nicole M; Ahn, Jiyoung; Nelson, Justin T; Landry, Markita P; Kruss, Sebastian; Strano, Michael S

    2016-01-01

    Corona phase molecular recognition (CoPhMoRe) uses a heteropolymer adsorbed onto and templated by a nanoparticle surface to recognize a specific target analyte. This method has not yet been extended to macromolecular analytes, including proteins. Herein we develop a variant of a CoPhMoRe screening procedure of single-walled carbon nanotubes (SWCNT) and use it against a panel of human blood proteins, revealing a specific corona phase that recognizes fibrinogen with high selectivity. In response to fibrinogen binding, SWCNT fluorescence decreases by >80% at saturation. Sequential binding of the three fibrinogen nodules is suggested by selective fluorescence quenching by isolated sub-domains and validated by the quenching kinetics. The fibrinogen recognition also occurs in serum environment, at the clinically relevant fibrinogen concentrations in the human blood. These results open new avenues for synthetic, non-biological antibody analogues that recognize biological macromolecules, and hold great promise for medical and clinical applications. PMID:26742890

  12. Protein-targeted corona phase molecular recognition

    PubMed Central

    Bisker, Gili; Dong, Juyao; Park, Hoyoung D.; Iverson, Nicole M.; Ahn, Jiyoung; Nelson, Justin T.; Landry, Markita P.; Kruss, Sebastian; Strano, Michael S.

    2016-01-01

    Corona phase molecular recognition (CoPhMoRe) uses a heteropolymer adsorbed onto and templated by a nanoparticle surface to recognize a specific target analyte. This method has not yet been extended to macromolecular analytes, including proteins. Herein we develop a variant of a CoPhMoRe screening procedure of single-walled carbon nanotubes (SWCNT) and use it against a panel of human blood proteins, revealing a specific corona phase that recognizes fibrinogen with high selectivity. In response to fibrinogen binding, SWCNT fluorescence decreases by >80% at saturation. Sequential binding of the three fibrinogen nodules is suggested by selective fluorescence quenching by isolated sub-domains and validated by the quenching kinetics. The fibrinogen recognition also occurs in serum environment, at the clinically relevant fibrinogen concentrations in the human blood. These results open new avenues for synthetic, non-biological antibody analogues that recognize biological macromolecules, and hold great promise for medical and clinical applications. PMID:26742890

  13. Photonics: From target recognition to lesion detection

    NASA Technical Reports Server (NTRS)

    Henry, E. Michael

    1994-01-01

    Since 1989, Martin Marietta has invested in the development of an innovative concept for robust real-time pattern recognition for any two-dimensioanal sensor. This concept has been tested in simulation, and in laboratory and field hardware, for a number of DOD and commercial uses from automatic target recognition to manufacturing inspection. We have now joined Rose Health Care Systems in developing its use for medical diagnostics. The concept is based on determining regions of interest by using optical Fourier bandpassing as a scene segmentation technique, enhancing those regions using wavelet filters, passing the enhanced regions to a neural network for analysis and initial pattern identification, and following this initial identification with confirmation by optical correlation. The optical scene segmentation and pattern confirmation are performed by the same optical module. The neural network is a recursive error minimization network with a small number of connections and nodes that rapidly converges to a global minimum.

  14. Testing Saliency Parameters for Automatic Target Recognition

    NASA Technical Reports Server (NTRS)

    Pandya, Sagar

    2012-01-01

    A bottom-up visual attention model (the saliency model) is tested to enhance the performance of Automated Target Recognition (ATR). JPL has developed an ATR system that identifies regions of interest (ROI) using a trained OT-MACH filter, and then classifies potential targets as true- or false-positives using machine-learning techniques. In this project, saliency is used as a pre-processing step to reduce the space for performing OT-MACH filtering. Saliency parameters, such as output level and orientation weight, are tuned to detect known target features. Preliminary results are promising and future work entails a rigrous and parameter-based search to gain maximum insight about this method.

  15. Software for Partly Automated Recognition of Targets

    NASA Technical Reports Server (NTRS)

    Opitz, David; Blundell, Stuart; Bain, William; Morris, Matthew; Carlson, Ian; Mangrich, Mark

    2003-01-01

    The Feature Analyst is a computer program for assisted (partially automated) recognition of targets in images. This program was developed to accelerate the processing of high-resolution satellite image data for incorporation into geographic information systems (GIS). This program creates an advanced user interface that embeds proprietary machine-learning algorithms in commercial image-processing and GIS software. A human analyst provides samples of target features from multiple sets of data, then the software develops a data-fusion model that automatically extracts the remaining features from selected sets of data. The program thus leverages the natural ability of humans to recognize objects in complex scenes, without requiring the user to explain the human visual recognition process by means of lengthy software. Two major subprograms are the reactive agent and the thinking agent. The reactive agent strives to quickly learn the user s tendencies while the user is selecting targets and to increase the user s productivity by immediately suggesting the next set of pixels that the user may wish to select. The thinking agent utilizes all available resources, taking as much time as needed, to produce the most accurate autonomous feature-extraction model possible.

  16. Image understanding research for automatic target recognition

    SciTech Connect

    Bhanu, B. ); Jones, T.L. )

    1993-10-01

    Automatic Target Recognition (ATR) is an extremely important capability for defense applications. Many aspects of Image Understanding (IU) research are traditionally used to solve ATR problems. In this paper, the authors discuss ATR applications and problems in developing real-world ATR systems, and present the status of technology for these systems. They identify several IU problems that need to be resolved in order to enhance the effectiveness of ATR-based weapon systems. Finally, they conclude that technological gains in developing robust ATR systems will also lead to significant advances in many other areas of applications of image understanding.

  17. Feature Extraction and Selection Strategies for Automated Target Recognition

    NASA Technical Reports Server (NTRS)

    Greene, W. Nicholas; Zhang, Yuhan; Lu, Thomas T.; Chao, Tien-Hsin

    2010-01-01

    Several feature extraction and selection methods for an existing automatic target recognition (ATR) system using JPLs Grayscale Optical Correlator (GOC) and Optimal Trade-Off Maximum Average Correlation Height (OT-MACH) filter were tested using MATLAB. The ATR system is composed of three stages: a cursory region of-interest (ROI) search using the GOC and OT-MACH filter, a feature extraction and selection stage, and a final classification stage. Feature extraction and selection concerns transforming potential target data into more useful forms as well as selecting important subsets of that data which may aide in detection and classification. The strategies tested were built around two popular extraction methods: Principal Component Analysis (PCA) and Independent Component Analysis (ICA). Performance was measured based on the classification accuracy and free-response receiver operating characteristic (FROC) output of a support vector machine(SVM) and a neural net (NN) classifier.

  18. A real-time optical automatic target recognition system

    NASA Astrophysics Data System (ADS)

    Chen, Huaixin; Nan, Jianshe; Li, Xiaosun; Wei, Honggang

    2004-04-01

    Automatic target recognition (ATR) technique has been applied in both civil and military. In this paper, we present a new optical pattern recognition system for target recognition. This system includes synthetic discriminate function (SDF) based practical optimized filters for the 3-D targets, the Reference Filter Libs for high correlation SNR, the mapping between the input (object regions) and the output (correlation peaks), and neural networks (ANN) for final decision making. The Real-time optical target recognition is realized by temporal multiplexing technique with electronic addressing spatial light modulator. The experiment results show that the proposed OPR system is efficient and reliable.

  19. Remote weapon station for automatic target recognition system demand analysis

    NASA Astrophysics Data System (ADS)

    Lei, Zhang; Li, Sheng-cai; Shi, Cai

    2015-08-01

    Introduces a remote weapon station basic composition and the main advantage, analysis of target based on image automatic recognition system for remote weapon station of practical significance, the system elaborated the image based automatic target recognition system in the photoelectric stabilized technology, multi-sensor image fusion technology, integrated control target image enhancement, target behavior risk analysis technology, intelligent based on the character of the image automatic target recognition algorithm research, micro sensor technology as the key technology of the development in the field of demand.

  20. A universal entropy-driven mechanism for thioredoxin-target recognition.

    PubMed

    Palde, Prakash B; Carroll, Kate S

    2015-06-30

    Cysteine residues in cytosolic proteins are maintained in their reduced state, but can undergo oxidation owing to posttranslational modification during redox signaling or under conditions of oxidative stress. In large part, the reduction of oxidized protein cysteines is mediated by a small 12-kDa thiol oxidoreductase, thioredoxin (Trx). Trx provides reducing equivalents for central metabolic enzymes and is implicated in redox regulation of a wide number of target proteins, including transcription factors. Despite its importance in cellular redox homeostasis, the precise mechanism by which Trx recognizes target proteins, especially in the absence of any apparent signature binding sequence or motif, remains unknown. Knowledge of the forces associated with the molecular recognition that governs Trx-protein interactions is fundamental to our understanding of target specificity. To gain insight into Trx-target recognition, we have thermodynamically characterized the noncovalent interactions between Trx and target proteins before S-S reduction using isothermal titration calorimetry (ITC). Our findings indicate that Trx recognizes the oxidized form of its target proteins with exquisite selectivity, compared with their reduced counterparts. Furthermore, we show that recognition is dependent on the conformational restriction inherent to oxidized targets. Significantly, the thermodynamic signatures for multiple Trx targets reveal favorable entropic contributions as the major recognition force dictating these protein-protein interactions. Taken together, our data afford significant new insight into the molecular forces responsible for Trx-target recognition and should aid the design of new strategies for thiol oxidoreductase inhibition. PMID:26080424

  1. Automatic target recognition apparatus and method

    DOEpatents

    Baumgart, Chris W.; Ciarcia, Christopher A.

    2000-01-01

    An automatic target recognition apparatus (10) is provided, having a video camera/digitizer (12) for producing a digitized image signal (20) representing an image containing therein objects which objects are to be recognized if they meet predefined criteria. The digitized image signal (20) is processed within a video analysis subroutine (22) residing in a computer (14) in a plurality of parallel analysis chains such that the objects are presumed to be lighter in shading than the background in the image in three of the chains and further such that the objects are presumed to be darker than the background in the other three chains. In two of the chains the objects are defined by surface texture analysis using texture filter operations. In another two of the chains the objects are defined by background subtraction operations. In yet another two of the chains the objects are defined by edge enhancement processes. In each of the analysis chains a calculation operation independently determines an error factor relating to the probability that the objects are of the type which should be recognized, and a probability calculation operation combines the results of the analysis chains.

  2. A proposal for combining mapping, localization and target recognition

    NASA Astrophysics Data System (ADS)

    Grönwall, Christina; Hendeby, Gustaf; Sinivaara, Kristian

    2015-10-01

    Simultaneous localization and mapping (SLAM) is a well-known positioning approach in GPS-denied environments such as urban canyons and inside buildings. Autonomous/aided target detection and recognition (ATR) is commonly used in military application to detect threats and targets in outdoor environments. This papers present approaches to combine SLAM with ATR in ways that compensate for the drawbacks in each method. The methods use physical objects that are recognizable by ATR as unambiguous features in SLAM, while SLAM provides the ATR with better position estimates. Landmarks in the form of 3D point features based on normal aligned radial features (NARF) are used in conjunction with identified objects and 3D object models that replace landmarks when possible. This leads to a more compact map representation with fewer landmarks, which partly compensates for the introduced cost of the ATR. We analyze three approaches to combine SLAM and 3D-data; point-point matching ignoring NARF features, point-point matching using the set of points that are selected by NARF feature analysis, and matching of NARF features using nearest neighbor analysis. The first two approaches are is similar to the common iterative closest point (ICP). We propose an algorithm that combines EKF-SLAM and ATR based on rectangle estimation. The intended application is to improve the positioning of a first responder moving through an indoor environment, where the map offers localization and simultaneously helps locate people, furniture and potentially dangerous objects such as gas canisters.

  3. Local sequence targeting in the AID/APOBEC family differentially impacts retroviral restriction and antibody diversification.

    PubMed

    Kohli, Rahul M; Maul, Robert W; Guminski, Amy F; McClure, Rhonda L; Gajula, Kiran S; Saribasak, Huseyin; McMahon, Moira A; Siliciano, Robert F; Gearhart, Patricia J; Stivers, James T

    2010-12-24

    Nucleic acid cytidine deaminases of the activation-induced deaminase (AID)/APOBEC family are critical players in active and innate immune responses, playing roles as target-directed, purposeful mutators. AID specifically deaminates the host immunoglobulin (Ig) locus to evolve antibody specificity, whereas its close relative, APOBEC3G (A3G), lethally mutates the genomes of retroviral pathogens such as HIV. Understanding the basis for the target-specific action of these enzymes is essential, as mistargeting poses significant risks, potentially promoting oncogenesis (AID) or fostering drug resistance (A3G). AID prefers to deaminate cytosine in WRC (W = A/T, R = A/G) motifs, whereas A3G favors deamination of CCC motifs. This specificity is largely dictated by a single, divergent protein loop in the enzyme family that recognizes the DNA sequence. Through grafting of this substrate-recognition loop, we have created enzyme variants of A3G and AID with altered local targeting to directly evaluate the role of sequence specificity on immune function. We find that grafted loops placed in the A3G scaffold all produced efficient restriction of HIV but that foreign loops in the AID scaffold compromised hypermutation and class switch recombination. Local targeting, therefore, appears alterable for innate defense against retroviruses by A3G but important for adaptive antibody maturation catalyzed by AID. Notably, AID targeting within the Ig locus is proportionally correlated to its in vitro ability to target WRC sequences rather than non-WRC sequences. Although other mechanisms may also contribute, our results suggest that local sequence targeting by AID/APOBEC3 enzymes represents an elegant example of co-evolution of enzyme specificity with its target DNA sequence.

  4. Radar target recognition using non-cooperative scatterer matching game

    NASA Astrophysics Data System (ADS)

    Jouny, Ismail

    2012-05-01

    This paper utilizes game-theoretic principles in the automatic recognition of unknown radar targets. This study uses a non-cooperative matching game where pure strategies are associated with specific items to be matched, and agreement between possible hypotheses represents the payoff gained when playing a certain strategy against an opponent who is playing another strategy. The target recognition approach attempts to match scattering centers of an unknown target with those of library targets as competing strategies. The algorithm is tested using real radar data representing scattering from commercial aircraft models. Radar data of library targets at various azimuth positions are matched against an unknown radar target signature at a specific aspect angle. Computer simulations provide an estimate of the error rates in scenarios of additive Gaussian noise corrupting target signatures.

  5. Target recognition using HRR profile-based incoherent SAR (InSAR) image formation

    NASA Astrophysics Data System (ADS)

    O'Donoughue, Nicholas A.; Kuklinski, Walter S.; Arabadjis, Constantine

    2008-04-01

    Feature-aided target verification is a challenging field of research, with the potential to yield significant increases in the confidence of re-established target tracks after kinematic confusion events. Using appropriate control algorithms airborne multi-mode radars can acquire a library of HRR (High Range Resolution) profiles for targets as they are tracked. When a kinematic confusion event occurs, such as a vehicle dropping below MDV (Minimum Detectable Velocity) for some period of time, or two target tracks crossing, it is necessary to utilize feature-aided tracking methods to correctly associate post-confusion tracks with pre-confusion tracks. Many current HRR profile target recognition methods focus on statistical characteristics of either individual profiles or sets of profiles taken over limited viewing angles. These methods have not proven to be very effective when the pre- and post- confusion libraries do not overlap in azimuth angle. To address this issue we propose a new approach to target recognition from HRR profiles. We present an algorithm that generates 2-D imagery of targets from the pre- and post-confusion libraries. These images are subsequently used as the input to a target recognition/classifier process. Since, center-aligned HRR Profiles, while ideal for processing, are not easily computed in field systems, as they require the airborne platform's center of rotation to line up with the geometric center of the moving target (this is impossible when multiple targets are being tracked), our algorithm is designed to work with HRR profiles that are aligned to the leading edge (the first detection above a threshold, commonly referred to as Edge-Aligned HRR profiles). Our simulated results demonstrate the effectiveness of this method for classifying target vehicles based on simulations using both overlapping and non-overlapping HRR profile sets. The algorithm was tested on several test cases using an input set of .28 m resolution XPATCH generated HRR

  6. Parallel algorithm for target recognition using a multiclass hash database

    NASA Astrophysics Data System (ADS)

    Uddin, Mosleh; Myler, Harley R.

    1998-07-01

    A method for recognition of unknown targets using large databases of model targets is discussed. Our approach is based on parallel processing of multi-class hash databases that are generated off-line. A geometric hashing technique is used on feature points of model targets to create each class database. Bit level coding is then performed to represent the models in an image format. Parallelism is achieved during the recognition phase. Feature points of an unknown target are passed to parallel processors each accessing an individual class database. Each processor reads a particular class of hash data base and indexes feature points of the unknown target. A simple voting technique is applied to determine the best match model with the unknown. The paper discusses our technique and the results from testing with unknown FLIR targets.

  7. Targeting of AID-mediated sequence diversification to immunoglobulin genes.

    PubMed

    Kothapalli, Naga Rama; Fugmann, Sebastian D

    2011-04-01

    Activation-induced cytidine deaminase (AID) is a key enzyme for antibody-mediated immune responses. Antibodies are encoded by the immunoglobulin genes and AID acts as a transcription-dependent DNA mutator on these genes to improve antibody affinity and effector functions. An emerging theme in field is that many transcribed genes are potential targets of AID, presenting an obvious danger to genomic integrity. Thus there are mechanisms in place to ensure that mutagenic outcomes of AID activity are specifically restricted to the immunoglobulin loci. Cis-regulatory targeting elements mediate this effect and their mode of action is probably a combination of immunoglobulin gene specific activation of AID and a perversion of faithful DNA repair towards error-prone outcomes.

  8. Composite Wavelet Filters for Enhanced Automated Target Recognition

    NASA Technical Reports Server (NTRS)

    Chiang, Jeffrey N.; Zhang, Yuhan; Lu, Thomas T.; Chao, Tien-Hsin

    2012-01-01

    Automated Target Recognition (ATR) systems aim to automate target detection, recognition, and tracking. The current project applies a JPL ATR system to low-resolution sonar and camera videos taken from unmanned vehicles. These sonar images are inherently noisy and difficult to interpret, and pictures taken underwater are unreliable due to murkiness and inconsistent lighting. The ATR system breaks target recognition into three stages: 1) Videos of both sonar and camera footage are broken into frames and preprocessed to enhance images and detect Regions of Interest (ROIs). 2) Features are extracted from these ROIs in preparation for classification. 3) ROIs are classified as true or false positives using a standard Neural Network based on the extracted features. Several preprocessing, feature extraction, and training methods are tested and discussed in this paper.

  9. Composite wavelet filters for enhanced automated target recognition

    NASA Astrophysics Data System (ADS)

    Chiang, Jeffrey N.; Zhang, Yuhan; Lu, Thomas T.; Chao, Tien-Hsin

    2012-04-01

    Automated Target Recognition (ATR) systems aim to automate target detection, recognition, and tracking. The current project applies a JPL ATR system to low-resolution sonar and camera videos taken from unmanned vehicles. These sonar images are inherently noisy and difficult to interpret, and pictures taken underwater were unreliable due to murkiness and inconsistent lighting. The ATR system breaks target recognition into three stages: 1) Videos of both sonar and camera footage are broken into frames and preprocessed to enhance images and detect Regions of Interest (ROIs). 2) Features are extracted from these ROIs in preparation for classification. 3) ROIs are classified as true or false positives using a standard Neural Network based on the extracted features. Several preprocessing, feature extraction, and training methods are tested and discussed in this report.

  10. A computer aided treatment event recognition system in radiation therapy

    SciTech Connect

    Xia, Junyi Mart, Christopher; Bayouth, John

    2014-01-15

    Purpose: To develop an automated system to safeguard radiation therapy treatments by analyzing electronic treatment records and reporting treatment events. Methods: CATERS (Computer Aided Treatment Event Recognition System) was developed to detect treatment events by retrieving and analyzing electronic treatment records. CATERS is designed to make the treatment monitoring process more efficient by automating the search of the electronic record for possible deviations from physician's intention, such as logical inconsistencies as well as aberrant treatment parameters (e.g., beam energy, dose, table position, prescription change, treatment overrides, etc). Over a 5 month period (July 2012–November 2012), physicists were assisted by the CATERS software in conducting normal weekly chart checks with the aims of (a) determining the relative frequency of particular events in the authors’ clinic and (b) incorporating these checks into the CATERS. During this study period, 491 patients were treated at the University of Iowa Hospitals and Clinics for a total of 7692 fractions. Results: All treatment records from the 5 month analysis period were evaluated using all the checks incorporated into CATERS after the training period. About 553 events were detected as being exceptions, although none of them had significant dosimetric impact on patient treatments. These events included every known event type that was discovered during the trial period. A frequency analysis of the events showed that the top three types of detected events were couch position override (3.2%), extra cone beam imaging (1.85%), and significant couch position deviation (1.31%). The significant couch deviation is defined as the number of treatments where couch vertical exceeded two times standard deviation of all couch verticals, or couch lateral/longitudinal exceeded three times standard deviation of all couch laterals and longitudinals. On average, the application takes about 1 s per patient when

  11. Method on camouflaged target recognition using the angle of ellipsometry

    NASA Astrophysics Data System (ADS)

    Zhuansun, Xiao-bo; Wu, Wen-Yuan; Huang, Yan-hua; Li, Zhao-zhao

    2015-10-01

    Using polarimetric information of the camouflaged target surface to identify camouflage has been a hot research area in camouflage detecting. The main method is to use the difference in the degree of polarization(DOP) between background and target to add the contrast ratio of them. The measurement of the DOP has some requirements on the intensity of reflected radiation. In case of low reflected radiation intensity, the difference in the DOP for different materials is not so distinguishable. In addition, the linear degree of polarization is largely under the effects of detection angle and surface roughness, so it is hard to differentiate the degree of polarization when the targets with similar surface roughness are detected at the same detection angle. By analyzing the elements affecting the reflected electromagnetic radiation amplitudes and phase on the camouflaged target surface, this article makes a research on the polarization character of reflected radiation A method on camouflaged target recognition directly or indirectly by taking the angle of ellipsometry (AOE) imaging under the linear polarized light. The function model of the angle of incidence, complex refractive index and AOE was modeled, then the model was simulated by MATLAB and the results showed it can describe the distribution properties of AOE. A new thought for the approach of identifying camouflaged target recognition by detecting polarimetric information was proposed, and it has a deep theoretical and practical significance in camouflaged target recognition.

  12. Wavelet-based learning vector quantization for automatic target recognition

    NASA Astrophysics Data System (ADS)

    Chan, Lipchen A.; Nasrabadi, Nasser M.; Mirelli, Vincent

    1996-06-01

    An automatic target recognition classifier is constructed that uses a set of dedicated vector quantizers (VQs). The background pixels in each input image are properly clipped out by a set of aspect windows. The extracted target area for each aspect window is then enlarged to a fixed size, after which a wavelet decomposition splits the enlarged extraction into several subbands. A dedicated VQ codebook is generated for each subband of a particular target class at a specific range of aspects. Thus, each codebook consists of a set of feature templates that are iteratively adapted to represent a particular subband of a given target class at a specific range of aspects. These templates are then further trained by a modified learning vector quantization (LVQ) algorithm that enhances their discriminatory characteristics. A recognition rate of 69.0 percent is achieved on a highly cluttered test set.

  13. Automated target recognition and tracking using an optical pattern recognition neural network

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin

    1991-01-01

    The on-going development of an automatic target recognition and tracking system at the Jet Propulsion Laboratory is presented. This system is an optical pattern recognition neural network (OPRNN) that is an integration of an innovative optical parallel processor and a feature extraction based neural net training algorithm. The parallel optical processor provides high speed and vast parallelism as well as full shift invariance. The neural network algorithm enables simultaneous discrimination of multiple noisy targets in spite of their scales, rotations, perspectives, and various deformations. This fully developed OPRNN system can be effectively utilized for the automated spacecraft recognition and tracking that will lead to success in the Automated Rendezvous and Capture (AR&C) of the unmanned Cargo Transfer Vehicle (CTV). One of the most powerful optical parallel processors for automatic target recognition is the multichannel correlator. With the inherent advantages of parallel processing capability and shift invariance, multiple objects can be simultaneously recognized and tracked using this multichannel correlator. This target tracking capability can be greatly enhanced by utilizing a powerful feature extraction based neural network training algorithm such as the neocognitron. The OPRNN, currently under investigation at JPL, is constructed with an optical multichannel correlator where holographic filters have been prepared using the neocognitron training algorithm. The computation speed of the neocognitron-type OPRNN is up to 10(exp 14) analog connections/sec that enabling the OPRNN to outperform its state-of-the-art electronics counterpart by at least two orders of magnitude.

  14. Automatic target recognition using group-structured sparse representation

    NASA Astrophysics Data System (ADS)

    Sun, Bo; Wu, Xuewen; He, Jun; Zhu, Xiaoming; Chen, Chao

    2014-06-01

    Sparse representation classification method has been increasingly used in the fields of computer vision and pattern analysis, due to its high recognition rate, little dependence on the features, robustness to corruption and occlusion, and etc. However, most of these existing methods aim to find the sparsest representations of the test sample y in an overcomplete dictionary, which do not particularly consider the relevant structure between the atoms in the dictionary. Moreover, sufficient training samples are always required by the sparse representation method for effective recognition. In this paper we formulate the classification as a group-structured sparse representation problem using a sparsity-inducing norm minimization optimization and propose a novel sparse representation-based automatic target recognition (ATR) framework for the practical applications in which the training samples are drawn from the simulation models of real targets. The experimental results show that the proposed approach improves the recognition rate of standard sparse models, and our system can effectively and efficiently recognize targets under real environments, especially, where the good characteristics of the sparse representation based classification method are kept.

  15. Bayesian multi-target tracking and sequential object recognition

    NASA Astrophysics Data System (ADS)

    Armbruster, Walter

    2008-04-01

    The paper considers the following problem: given a 3D model of a reference target and a sequence of images of a 3D scene, identify the object in the scene most likely to be the reference target and determine its current pose. Finding the best match in each frame independently of previous decisions is not optimal, since past information is ignored. Our solution concept uses a novel Bayesian framework for multi target tracking and object recognition to define and sequentially update the probability that the reference target is any one of the tracked objects. The approach is applied to problems of automatic lock-on and missile guidance using a laser radar seeker. Field trials have resulted in high target hit probabilities despite low resolution imagery and temporarily highly occluded targets.

  16. Automatic target recognition using vector quantization and neural networks

    NASA Astrophysics Data System (ADS)

    Chan, Lipchen A.; Nasrabadi, Nasser M.

    1999-12-01

    We propose an automatic target recognition (ATR) algorithm that uses a set of dedicated vector quantizers (VQs) and multilayer perceptrons (MLPs). For each target class at a specific range of aspects, the background pixels of an input image are first removed. The extracted target area is then subdivided into several subimages. A dedicated VQ codebook is constructed for each of the resulting subimages. Using the K-means algorithm, each VQ codebook learns a set of patterns representing the local features of a particular target for a specific range of aspects. The resulting codebooks are further trained by a modified learning vector quantization algorithm, which enhances the discriminatory power of the codebooks. Each final codebook is expected to give the lowest mean squared error (MSE) for its correct target class and range of aspects. These MSEs are then input to an array of window-level MLPs (WMLPs), where each WMLP is specialized in recognizing its intended target class for a specific range of aspects. The outputs of these WMLPs are manipulated and passed to a target-level MLP, which produces the final recognition results. We trained and tested the proposed ATR algorithm on large and realistic data sets and obtained impressive results using the wavelet-based adaptive produce VQs configuration.

  17. Advanced automatic target recognition for police helicopter missions

    NASA Astrophysics Data System (ADS)

    Stahl, Christoph; Schoppmann, Paul

    2000-08-01

    The results of a case study about the application of an advanced method for automatic target recognition to infrared imagery taken from police helicopter missions are presented. The method consists of the following steps: preprocessing, classification, fusion, postprocessing and tracking, and combines the three paradigms image pyramids, neural networks and bayesian nets. The technology has been developed using a variety of different scenes typical for military aircraft missions. Infrared cameras have been in use for several years at the Bavarian police helicopter forces and are highly valuable for night missions. Several object classes like 'persons' or 'vehicles' are tested and the possible discrimination between persons and animals is shown. The analysis of complex scenes with hidden objects and clutter shows the potentials and limitations of automatic target recognition for real-world tasks. Several display concepts illustrate the achievable improvement of the situation awareness. The similarities and differences between various mission types concerning object variability, time constraints, consequences of false alarms, etc. are discussed. Typical police actions like searching for missing persons or runaway criminals illustrate the advantages of automatic target recognition. The results demonstrate the possible operational benefits for the helicopter crew. Future work will include performance evaluation issues and a system integration concept for the target platform.

  18. Automated Target Acquisition, Recognition and Tracking (ATTRACT). Phase 1

    NASA Technical Reports Server (NTRS)

    Abdallah, Mahmoud A.

    1995-01-01

    The primary objective of phase 1 of this research project is to conduct multidisciplinary research that will contribute to fundamental scientific knowledge in several of the USAF critical technology areas. Specifically, neural networks, signal processing techniques, and electro-optic capabilities are utilized to solve problems associated with automated target acquisition, recognition, and tracking. To accomplish the stated objective, several tasks have been identified and were executed.

  19. How does susceptibility to proactive interference relate to speech recognition in aided and unaided conditions?

    PubMed Central

    Ellis, Rachel J.; Rönnberg, Jerker

    2015-01-01

    Proactive interference (PI) is the capacity to resist interference to the acquisition of new memories from information stored in the long-term memory. Previous research has shown that PI correlates significantly with the speech-in-noise recognition scores of younger adults with normal hearing. In this study, we report the results of an experiment designed to investigate the extent to which tests of visual PI relate to the speech-in-noise recognition scores of older adults with hearing loss, in aided and unaided conditions. The results suggest that measures of PI correlate significantly with speech-in-noise recognition only in the unaided condition. Furthermore the relation between PI and speech-in-noise recognition differs to that observed in younger listeners without hearing loss. The findings suggest that the relation between PI tests and the speech-in-noise recognition scores of older adults with hearing loss relates to capability of the test to index cognitive flexibility. PMID:26283981

  20. Practical target recognition in infrared imagery using a neural network

    NASA Astrophysics Data System (ADS)

    Crowe, Alistair A.; Patel, A.; Wright, William A.; Green, Michael A.; Hughes, Andrew D.

    1992-07-01

    This paper describes work undertaken by British Aerospace (BAe) on the development of a neural network classifier for automatic recognition of land based targets in infrared imagery. The classifier used a histogram segmentation process to extract regions from the infrared imagery. A set of features were calculated for each region to form a feature vector describing the region. These feature vectors were then used as the input to the neural classifier. Two neural classifiers were investigated based upon the multi-layer perceptron and radial basis function networks. In order to assess the merits of a neural network approach, the neural classifiers were compared with a conventional classifier originally developed by British Aerospace (Systems and Equipment) Ltd., under contract to RARDE (Chertsey), for the purpose of infrared target recognition. This conventional system was based upon a Schurman classifier which operates on data transformed using a Hotelling Trace Transform. The ability of the classifiers to perform practical recognition of real-world targets was evaluated by training and testing the classifiers on real imagery obtained from mock land battles and military vehicle trials.

  1. Automated target recognition using passive radar and coordinated flight models

    NASA Astrophysics Data System (ADS)

    Ehrman, Lisa M.; Lanterman, Aaron D.

    2003-09-01

    Rather than emitting pulses, passive radar systems rely on illuminators of opportunity, such as TV and FM radio, to illuminate potential targets. These systems are particularly attractive since they allow receivers to operate without emitting energy, rendering them covert. Many existing passive radar systems estimate the locations and velocities of targets. This paper focuses on adding an automatic target recognition (ATR) component to such systems. Our approach to ATR compares the Radar Cross Section (RCS) of targets detected by a passive radar system to the simulated RCS of known targets. To make the comparison as accurate as possible, the received signal model accounts for aircraft position and orientation, propagation losses, and antenna gain patterns. The estimated positions become inputs for an algorithm that uses a coordinated flight model to compute probable aircraft orientation angles. The Fast Illinois Solver Code (FISC) simulates the RCS of several potential target classes as they execute the estimated maneuvers. The RCS is then scaled by the Advanced Refractive Effects Prediction System (AREPS) code to account for propagation losses that occur as functions of altitude and range. The Numerical Electromagnetic Code (NEC2) computes the antenna gain pattern, so that the RCS can be further scaled. The Rician model compares the RCS of the illuminated aircraft with those of the potential targets. This comparison results in target identification.

  2. Automatic air-to-ground target recognition using LWIR FPAs

    NASA Astrophysics Data System (ADS)

    Amadieu, Jean-Louis; Fraysse, Vincent

    1996-06-01

    The theoretical potential of optical sensors in terms of geometrical resolution makes them the ideal solution for achieving the terminal precision guidance of today's missiles. This paper describes such a sensor, working in the 8 to 12 micrometer spectral domain by using a 64 by 64 IRCCD focal plane array, and whose main mission is to recognize various types of armored vehicles within complex scenes that possibly include other vehicles of similar nature. The target recognition process is based upon a Bayesian approach and can be briefly described as follows: after a classical processing stage that performs the filtering and the multi- thresholding, the target recognition algorithm evaluates a similarity level between the objects, including the target, seen in the IR scene and the 'theoretical' target whose some mean, generic features have been implemented in a database. The surroundings of the target and its orientation in the IR scene are 'a priori' unknown. The similarity level is based on calculation of the Mahalanobis distance between the object features vector and the mean features vector of the model; this calculation involves a covariance matrix which is significant of the errors affecting the measured features and that in particular stem form the limited spatial resolution of the sensor, the detector noise and the sensor- to-target range estimation error. With respect to the sensor hardware, its main opto-mechanical characteristics as well as some electro-optics data are indicates; some examples of target acquisition in complex scenes involving different kinds of IR counter measures are also presented.

  3. Embedded knowledge-based system for automatic target recognition

    NASA Astrophysics Data System (ADS)

    Aboutalib, A. O.

    1990-10-01

    The development of a reliable Automatic Target Recognition (ATE) system is considered a very critical and challenging problem. Existing ATE Systems have inherent limitations in terms of recognition performance and the ability to learn and adapt. Artificial Intelligence Techniques have the potential to improve the performance of ATh Systems. In this paper, we presented a novel Knowledge-Engineering tool, termed, the Automatic Reasoning Process (ARP) , that can be used to automatically develop and maintain a Knowledge-Base (K-B) for the ATR Systems. In its learning mode, the ARP utilizes Learning samples to automatically develop the ATR K-B, which consists of minimum size sets of necessary and sufficient conditions for each target class. In its operational mode, the ARP infers the target class from sensor data using the ATh K-B System. The ARP also has the capability to reason under uncertainty, and can support both statistical and model-based approaches for ATR development. The capabilities of the ARP are compared and contrasted to those of another Knowledge-Engineering tool, termed, the Automatic Rule Induction (ARI) which is based on maximizing the mutual information. The AR? has been implemented in LISP on a VAX-GPX workstation.

  4. Infrared target recognition based on improved joint local ternary pattern

    NASA Astrophysics Data System (ADS)

    Sun, Junding; Wu, Xiaosheng

    2016-05-01

    This paper presents a simple, efficient, yet robust approach, named joint orthogonal combination of local ternary pattern, for automatic forward-looking infrared target recognition. It gives more advantages to describe the macroscopic textures and microscopic textures by fusing variety of scales than the traditional LBP-based methods. In addition, it can effectively reduce the feature dimensionality. Further, the rotation invariant and uniform scheme, the robust LTP, and soft concave-convex partition are introduced to enhance its discriminative power. Experimental results demonstrate that the proposed method can achieve competitive results compared with the state-of-the-art methods.

  5. Feature-aided multiple target tracking in the image plane

    NASA Astrophysics Data System (ADS)

    Brown, Andrew P.; Sullivan, Kevin J.; Miller, David J.

    2006-05-01

    Vast quantities of EO and IR data are collected on airborne platforms (manned and unmanned) and terrestrial platforms (including fixed installations, e.g., at street intersections), and can be exploited to aid in the global war on terrorism. However, intelligent preprocessing is required to enable operator efficiency and to provide commanders with actionable target information. To this end, we have developed an image plane tracker which automatically detects and tracks multiple targets in image sequences using both motion and feature information. The effects of platform and camera motion are compensated via image registration, and a novel change detection algorithm is applied for accurate moving target detection. The contiguous pixel blob on each moving target is segmented for use in target feature extraction and model learning. Feature-based target location measurements are used for tracking through move-stop-move maneuvers, close target spacing, and occlusion. Effective clutter suppression is achieved using joint probabilistic data association (JPDA), and confirmed target tracks are indicated for further processing or operator review. In this paper we describe the algorithms implemented in the image plane tracker and present performance results obtained with video clips from the DARPA VIVID program data collection and from a miniature unmanned aerial vehicle (UAV) flight.

  6. Aided speech recognition abilities of adults with a severe or severe-to-profound hearing loss.

    PubMed

    Flynn, M C; Dowell, R C; Clark, G M

    1998-04-01

    Adults with severe or severe-to-profound hearing losses constitute between 11% and 13.5% of the hearing-impaired population. A detailed investigation of the speech recognition of adults with severe (n = 20) or severe-to-profound (n = 14) hearing loss was conducted at The University of Melbourne. Each participant took part in a series of speech recognition tasks while wearing his or her currently fitted hearing aid(s). The assessments included closed-set tests of consonant recognition and vowel recognition, combined with open-set tests of monosyllabic word recognition and sentence recognition. Sentences were presented in quiet and in noise at +10 dB SNR to replicate an environment more typical of everyday listening conditions. Although the results demonstrated wide variability in performance, some general trends were observed. As expected vowels were generally well perceived compared with consonants. Monosyllabic word recognition scores for both the adults with a severe hearing impairment (M = 67.2%) and the adults with a severe-to-profound hearing impairment (M = 38.6%) could be predicted from the segmental tests, with an allowance for lexical effects. Scores for sentences presented in quiet showed additional linguistic effects and a significant decrease in performance with the addition of background noise (from 82.9% to 74.1% for adults with a severe hearing loss and from 55.8% to 34.2% for adults with a severe-to-profound hearing loss). Comparisons were made between the participants and a group of adults using a multiple-channel cochlear implant. This comparison indicated that some adults with a severe or severe-to-profound hearing loss may benefit from the use of a cochlear implant. The results of this study support the contention that cochlear implant candidacy should not rely solely on audiometric thresholds. PMID:9570583

  7. Novel automatic target recognition approach for multispectral data

    NASA Astrophysics Data System (ADS)

    Salazar, Jose S.; Koch, Mark W.; Yocky, David A.

    2002-11-01

    Automating the detection and identification of significant threats using multispectral (MS) imagery is a critical issue in remote sensing. Unlike previous multispectral target recognition approaches, we utilize a three-stage process that not only takes into account the spectral content, but also the spatial information. The first stage applies a matched filter to the calibrated MS data. Here, the matched filter is tuned to the spectral components of a given target and produces an image intensity map of where the best matches occur. The second stage represents a novel detection algorithm, known as the focus of attention (FOA) stage. The FOA performs an initial screening of the data based on intensity and size checks on the matched filter output. Next, using the target's pure components, the third stage performs constrained linear unmixing on MS pixels within the FOA detected regions. Knowledge sources derived from this process are combined using a sequential probability ratio test (SPRT). The SPRT can fuse contaminated, uncertain and disparate information from multiple sources. We demonstrate our approach on identifying a specific target using actual data collected in ideal conditions and also use approximately 35 square kilometers of urban clutter as false alarm data.

  8. Assessing the performance of a covert automatic target recognition algorithm

    NASA Astrophysics Data System (ADS)

    Ehrman, Lisa M.; Lanterman, Aaron D.

    2005-05-01

    Passive radar systems exploit illuminators of opportunity, such as TV and FM radio, to illuminate potential targets. Doing so allows them to operate covertly and inexpensively. Our research seeks to enhance passive radar systems by adding automatic target recognition (ATR) capabilities. In previous papers we proposed conducting ATR by comparing the radar cross section (RCS) of aircraft detected by a passive radar system to the precomputed RCS of aircraft in the target class. To effectively model the low-frequency setting, the comparison is made via a Rician likelihood model. Monte Carlo simulations indicate that the approach is viable. This paper builds on that work by developing a method for quickly assessing the potential performance of the ATR algorithm without using exhaustive Monte Carlo trials. This method exploits the relation between the probability of error in a binary hypothesis test under the Bayesian framework to the Chernoff information. Since the data are well-modeled as Rician, we begin by deriving a closed-form approximation for the Chernoff information between two Rician densities. This leads to an approximation for the probability of error in the classification algorithm that is a function of the number of available measurements. We conclude with an application that would be particularly cumbersome to accomplish via Monte Carlo trials, but that can be quickly addressed using the Chernoff information approach. This application evaluates the length of time that an aircraft must be tracked before the probability of error in the ATR algorithm drops below a desired threshold.

  9. Dynamic relation between working memory capacity and speech recognition in noise during the first 6 months of hearing aid use.

    PubMed

    Ng, Elaine H N; Classon, Elisabet; Larsby, Birgitta; Arlinger, Stig; Lunner, Thomas; Rudner, Mary; Rönnberg, Jerker

    2014-01-01

    The present study aimed to investigate the changing relationship between aided speech recognition and cognitive function during the first 6 months of hearing aid use. Twenty-seven first-time hearing aid users with symmetrical mild to moderate sensorineural hearing loss were recruited. Aided speech recognition thresholds in noise were obtained in the hearing aid fitting session as well as at 3 and 6 months postfitting. Cognitive abilities were assessed using a reading span test, which is a measure of working memory capacity, and a cognitive test battery. Results showed a significant correlation between reading span and speech reception threshold during the hearing aid fitting session. This relation was significantly weakened over the first 6 months of hearing aid use. Multiple regression analysis showed that reading span was the main predictor of speech recognition thresholds in noise when hearing aids were first fitted, but that the pure-tone average hearing threshold was the main predictor 6 months later. One way of explaining the results is that working memory capacity plays a more important role in speech recognition in noise initially rather than after 6 months of use. We propose that new hearing aid users engage working memory capacity to recognize unfamiliar processed speech signals because the phonological form of these signals cannot be automatically matched to phonological representations in long-term memory. As familiarization proceeds, the mismatch effect is alleviated, and the engagement of working memory capacity is reduced. PMID:25421088

  10. Dynamic relation between working memory capacity and speech recognition in noise during the first 6 months of hearing aid use.

    PubMed

    Ng, Elaine H N; Classon, Elisabet; Larsby, Birgitta; Arlinger, Stig; Lunner, Thomas; Rudner, Mary; Rönnberg, Jerker

    2014-11-23

    The present study aimed to investigate the changing relationship between aided speech recognition and cognitive function during the first 6 months of hearing aid use. Twenty-seven first-time hearing aid users with symmetrical mild to moderate sensorineural hearing loss were recruited. Aided speech recognition thresholds in noise were obtained in the hearing aid fitting session as well as at 3 and 6 months postfitting. Cognitive abilities were assessed using a reading span test, which is a measure of working memory capacity, and a cognitive test battery. Results showed a significant correlation between reading span and speech reception threshold during the hearing aid fitting session. This relation was significantly weakened over the first 6 months of hearing aid use. Multiple regression analysis showed that reading span was the main predictor of speech recognition thresholds in noise when hearing aids were first fitted, but that the pure-tone average hearing threshold was the main predictor 6 months later. One way of explaining the results is that working memory capacity plays a more important role in speech recognition in noise initially rather than after 6 months of use. We propose that new hearing aid users engage working memory capacity to recognize unfamiliar processed speech signals because the phonological form of these signals cannot be automatically matched to phonological representations in long-term memory. As familiarization proceeds, the mismatch effect is alleviated, and the engagement of working memory capacity is reduced.

  11. Dynamic Relation Between Working Memory Capacity and Speech Recognition in Noise During the First 6 Months of Hearing Aid Use

    PubMed Central

    Classon, Elisabet; Larsby, Birgitta; Arlinger, Stig; Lunner, Thomas; Rudner, Mary; Rönnberg, Jerker

    2014-01-01

    The present study aimed to investigate the changing relationship between aided speech recognition and cognitive function during the first 6 months of hearing aid use. Twenty-seven first-time hearing aid users with symmetrical mild to moderate sensorineural hearing loss were recruited. Aided speech recognition thresholds in noise were obtained in the hearing aid fitting session as well as at 3 and 6 months postfitting. Cognitive abilities were assessed using a reading span test, which is a measure of working memory capacity, and a cognitive test battery. Results showed a significant correlation between reading span and speech reception threshold during the hearing aid fitting session. This relation was significantly weakened over the first 6 months of hearing aid use. Multiple regression analysis showed that reading span was the main predictor of speech recognition thresholds in noise when hearing aids were first fitted, but that the pure-tone average hearing threshold was the main predictor 6 months later. One way of explaining the results is that working memory capacity plays a more important role in speech recognition in noise initially rather than after 6 months of use. We propose that new hearing aid users engage working memory capacity to recognize unfamiliar processed speech signals because the phonological form of these signals cannot be automatically matched to phonological representations in long-term memory. As familiarization proceeds, the mismatch effect is alleviated, and the engagement of working memory capacity is reduced. PMID:25421088

  12. Multi-Stage System for Automatic Target Recognition

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin; Lu, Thomas T.; Ye, David; Edens, Weston; Johnson, Oliver

    2010-01-01

    A multi-stage automated target recognition (ATR) system has been designed to perform computer vision tasks with adequate proficiency in mimicking human vision. The system is able to detect, identify, and track targets of interest. Potential regions of interest (ROIs) are first identified by the detection stage using an Optimum Trade-off Maximum Average Correlation Height (OT-MACH) filter combined with a wavelet transform. False positives are then eliminated by the verification stage using feature extraction methods in conjunction with neural networks. Feature extraction transforms the ROIs using filtering and binning algorithms to create feature vectors. A feedforward back-propagation neural network (NN) is then trained to classify each feature vector and to remove false positives. The system parameter optimizations process has been developed to adapt to various targets and datasets. The objective was to design an efficient computer vision system that can learn to detect multiple targets in large images with unknown backgrounds. Because the target size is small relative to the image size in this problem, there are many regions of the image that could potentially contain the target. A cursory analysis of every region can be computationally efficient, but may yield too many false positives. On the other hand, a detailed analysis of every region can yield better results, but may be computationally inefficient. The multi-stage ATR system was designed to achieve an optimal balance between accuracy and computational efficiency by incorporating both models. The detection stage first identifies potential ROIs where the target may be present by performing a fast Fourier domain OT-MACH filter-based correlation. Because threshold for this stage is chosen with the goal of detecting all true positives, a number of false positives are also detected as ROIs. The verification stage then transforms the regions of interest into feature space, and eliminates false positives using an

  13. Target detection and recognition improvements by use of spatiotemporal fusion.

    PubMed

    Chen, Hai-Wen; Sutha, Surachai; Olson, Teresa

    2004-01-10

    We developed spatiotemporal fusion techniques for improving target detection and automatic target recognition. We also investigated real IR (infrared) sensor clutter noise. The sensor noise was collected by an IR (256 x 256) sensor looking at various scenes (trees, grass, roads, buildings, etc.). More than 95% of the sensor pixels showed near-stationary sensor clutter noise that was uncorrelated between pixels as well as across time frames. However, in a few pixels (covering the grass near the road) the sensor noise showed nonstationary properties (with increasing or decreasing mean across time frames). The natural noise extracted from the IR sensor, as well as the computer-generated noise with Gaussian and Rayleigh distributions, was used to test and compare different spatiotemporal fusion strategies. Finally, we proposed two advanced detection schemes: the double-thresholding the reverse-thresholding techniques. These techniques may be applied to complicated clutter situations (e.g., very-high clutter or nonstationary clutter situations) where the traditional constant-false-alarm-ratio technique may fail. PMID:14735959

  14. Computer-Aided Drug Discovery and Design Targeting Ion Channels.

    PubMed

    Zhang, Qiansen; Gao, Zhaobing; Yang, Huaiyu

    2016-01-01

    Ion channels are widely expressed in living cells and play critical roles in various cellular biological functions. Dysfunctional ion channels can cause a variety of diseases, making ion channels attractive targets for drug discovery. Computational approaches, such as molecular docking and molecular dynamic simulations, provide economic and efficient tools for finding modulators of ion channels and for elucidating the action mechanisms of small molecules. In this review, we focus primarily on four types of ion channels (voltage-gated, ligand-gated, acid-sensing, and virus matrix 2 ion channels). The current advancements in computer-aided drug discovery and design targeting ion channels are summarized. First, ligand-based studies for drug design are briefly outlined. Then, we focus on the structurebased studies targeting pore domains, endogenous binding sites and allosteric sites of ion channels. Moreover, we also review the contribution of computational methods to the field of ligand binding and unbinding pathways of ion channels. Finally, we propose future developments for the field. PMID:26975507

  15. A Pathogenic Nematode Targets Recognition Proteins to Avoid Insect Defenses

    PubMed Central

    Toubarro, Duarte; Avila, Mónica Martinez; Montiel, Rafael; Simões, Nelson

    2013-01-01

    Steinernemacarpocapsae is a nematode pathogenic in a wide variety of insect species. The great pathogenicity of this nematode has been ascribed to its ability to overcome the host immune response; however, little is known about the mechanisms involved in this process. The analysis of an expressed sequence tags (EST) library in the nematode during the infective phase was performed and a highly abundant contig homologous to serine protease inhibitors was identified. In this work, we show that this contig is part of a 641-bp cDNA that encodes a BPTI-Kunitz family inhibitor (Sc-KU-4), which is up-regulated in the parasite during invasion and installation. Recombinant Sc-KU-4 protein was produced in Escherichia coli and shown to inhibit chymotrypsin and elastase activities in a dose-dependent manner by a competitive mechanism with Ki values of 1.8 nM and 2.6 nM, respectively. Sc-KU-4 also inhibited trypsin and thrombin activities to a lesser extent. Studies of the mode of action of Sc-KU-4 and its effects on insect defenses suggest that although Sc-KU-4 did not inhibit the activation of hemocytes or the formation of clotting fibers, it did inhibit hemocyte aggregation and the entrapment of foreign particles by fibers. Moreover, Sc-KU-4 avoided encapsulation and the deposition of clotting materials, which usually occurs in response to foreign particles. We show by protein-protein interaction that Sc-KU-4 targets recognition proteins of insect immune system such as masquerade-like and serine protease-like homologs. The interaction of Sc-KU-4 with these proteins explains the ability of the nematode to overcome host reactions and its large pathogenic spectrum, once these immune proteins are well conserved in insects. The discovery of this inhibitor targeting insect recognition proteins opens new avenues for the development of S. carpocapsae as a biological control agent and provides a new tool to study host-pathogen interactions. PMID:24098715

  16. A pathogenic nematode targets recognition proteins to avoid insect defenses.

    PubMed

    Toubarro, Duarte; Avila, Mónica Martinez; Montiel, Rafael; Simões, Nelson

    2013-01-01

    Steinernemacarpocapsae is a nematode pathogenic in a wide variety of insect species. The great pathogenicity of this nematode has been ascribed to its ability to overcome the host immune response; however, little is known about the mechanisms involved in this process. The analysis of an expressed sequence tags (EST) library in the nematode during the infective phase was performed and a highly abundant contig homologous to serine protease inhibitors was identified. In this work, we show that this contig is part of a 641-bp cDNA that encodes a BPTI-Kunitz family inhibitor (Sc-KU-4), which is up-regulated in the parasite during invasion and installation. Recombinant Sc-KU-4 protein was produced in Escherichia coli and shown to inhibit chymotrypsin and elastase activities in a dose-dependent manner by a competitive mechanism with Ki values of 1.8 nM and 2.6 nM, respectively. Sc-KU-4 also inhibited trypsin and thrombin activities to a lesser extent. Studies of the mode of action of Sc-KU-4 and its effects on insect defenses suggest that although Sc-KU-4 did not inhibit the activation of hemocytes or the formation of clotting fibers, it did inhibit hemocyte aggregation and the entrapment of foreign particles by fibers. Moreover, Sc-KU-4 avoided encapsulation and the deposition of clotting materials, which usually occurs in response to foreign particles. We show by protein-protein interaction that Sc-KU-4 targets recognition proteins of insect immune system such as masquerade-like and serine protease-like homologs. The interaction of Sc-KU-4 with these proteins explains the ability of the nematode to overcome host reactions and its large pathogenic spectrum, once these immune proteins are well conserved in insects. The discovery of this inhibitor targeting insect recognition proteins opens new avenues for the development of S. carpocapsae as a biological control agent and provides a new tool to study host-pathogen interactions.

  17. Activation of p53 Facilitates the Target Search in DNA by Enhancing the Target Recognition Probability.

    PubMed

    Itoh, Yuji; Murata, Agato; Sakamoto, Seiji; Nanatani, Kei; Wada, Takehiko; Takahashi, Satoshi; Kamagata, Kiyoto

    2016-07-17

    Tumor suppressor p53 binds to the target in a genome and regulates the expression of downstream genes. p53 searches for the target by combining three-dimensional diffusion and one-dimensional sliding along the DNA. To examine the regulation mechanism of the target binding, we constructed the pseudo-wild type (pseudo-WT), activated (S392E), and inactive (R248Q) mutants of p53 and observed their target binding in long DNA using single-molecule fluorescence imaging. The pseudo-WT sliding along the DNA showed many pass events over the target and possessed target recognition probability (TRP) of 7±2%. The TRP increased to 18±2% for the activated mutant but decreased to 0% for the inactive mutant. Furthermore, the fraction of the target binding by the one-dimensional sliding among the total binding events increased from 63±9% for the pseudo-WT to 87±2% for the activated mutant. Control of TRP upon activation, as demonstrated here for p53, might be a general activation mechanism of transcription factors.

  18. Computer-aided recognition of dental implants in X-ray images

    NASA Astrophysics Data System (ADS)

    Morais, Pedro; Queirós, Sandro; Moreira, António H. J.; Ferreira, Adriano; Ferreira, Ernesto; Duque, Duarte; Rodrigues, Nuno F.; Vilaça, João. L.

    2015-03-01

    Dental implant recognition in patients without available records is a time-consuming and not straightforward task. The traditional method is a complete user-dependent process, where the expert compares a 2D X-ray image of the dental implant with a generic database. Due to the high number of implants available and the similarity between them, automatic/semi-automatic frameworks to aide implant model detection are essential. In this study, a novel computer-aided framework for dental implant recognition is suggested. The proposed method relies on image processing concepts, namely: (i) a segmentation strategy for semi-automatic implant delineation; and (ii) a machine learning approach for implant model recognition. Although the segmentation technique is the main focus of the current study, preliminary details of the machine learning approach are also reported. Two different scenarios are used to validate the framework: (1) comparison of the semi-automatic contours against implant's manual contours of 125 X-ray images; and (2) classification of 11 known implants using a large reference database of 601 implants. Regarding experiment 1, 0.97±0.01, 2.24±0.85 pixels and 11.12±6 pixels of dice metric, mean absolute distance and Hausdorff distance were obtained, respectively. In experiment 2, 91% of the implants were successfully recognized while reducing the reference database to 5% of its original size. Overall, the segmentation technique achieved accurate implant contours. Although the preliminary classification results prove the concept of the current work, more features and an extended database should be used in a future work.

  19. Targeting of AIDS related encephalopathy using phenylalanine anchored lipidic nanocarrier.

    PubMed

    Vyas, Anil; Jain, Ankit; Hurkat, Pooja; Jain, Ashish; Jain, Sanjay K

    2015-07-01

    Transport of the anti-HIV agents across the blood-brain barrier (BBB) is a prerequisite to treat acquired immunodeficiency syndrome (AIDS) related encephalopathy. In the present study, we explored facilitated transport of efavirenz (EFV, a non-nucleoside reverse transcriptase inhibitor) across BBB using phenylalanine anchored solid lipid nanoparticles (PA-SLN). PA (amino acid micro-nutrient) was used as a ligand which facilitated carrier mediated transport (CMT) via l-amino acid transporter i.e. LAT1 to traverse BBB. PA was coupled to SLN via amide linkage using carbodiimide chemistry and coupling was confirmed by comparative infrared spectroscopic analysis. SLNs (SLN and PA-SLN) were nanometric in size (around 150nm) and possessed good entrapment efficiency (around 70%). In vitro drug release revealed controlled release pattern for more than 24h. In vivo studies showed 2-3-folds and 7-8-folds accumulation of PA-SLN in brain as compared to SLN and EFV, respectively. Further, transcytosis studies confirmed capability of PA-SLN to cross BBB i.e. 10-fold higher transcytosis potential as compared to EFV. Fluorescence microscopic imaging reassured enhanced brain localization of PA-SLN. Thus, PA-SLN improved the EFV bioavailability and maintained therapeutic levels in the brain for an extended period of time that can result in significant eradication of the viral load therein. Such nutrient mediated drug targeting could bring forth advances in biocompatible and biodegradable drug delivery systems. PMID:25988279

  20. Target recognition for ladar range image using slice image

    NASA Astrophysics Data System (ADS)

    Xia, Wenze; Han, Shaokun; Wang, Liang

    2015-12-01

    A shape descriptor and a complete shape-based recognition system using slice images as geometric feature descriptor for ladar range images are introduced. A slice image is a two-dimensional image generated by three-dimensional Hough transform and the corresponding mathematical transformation. The system consists of two processes, the model library construction and recognition. In the model library construction process, a series of range images are obtained after the model object is sampled at preset attitude angles. Then, all the range images are converted into slice images. The number of slice images is reduced by clustering analysis and finding a representation to reduce the size of the model library. In the recognition process, the slice image of the scene is compared with the slice image in the model library. The recognition results depend on the comparison. Simulated ladar range images are used to analyze the recognition and misjudgment rates, and comparison between the slice image representation method and moment invariants representation method is performed. The experimental results show that whether in conditions without noise or with ladar noise, the system has a high recognition rate and low misjudgment rate. The comparison experiment demonstrates that the slice image has better representation ability than moment invariants.

  1. Scene segmentation from motion in multispectral imagery to aid automatic human gait recognition

    NASA Astrophysics Data System (ADS)

    Pearce, Daniel; Harvey, Christophe; Day, Simon; Goffredo, Michela

    2007-10-01

    Primarily focused at military and security environments where there is a need to identify humans covertly and remotely; this paper outlines how recovering human gait biometrics from a multi-spectral imaging system can overcome the failings of traditional biometrics to fulfil those needs. With the intention of aiding single camera human gait recognition, an algorithm was developed to accurately segment a walking human from multi-spectral imagery. 16-band imagery from the image replicating imaging spectrometer (IRIS) camera system is used to overcome some of the common problems associated with standard change detection techniques. Fusing the concepts of scene segmentation by spectral characterisation and background subtraction by image differencing gives a uniquely robust approach. This paper presents the results of real trials with human subjects and a prototype IRIS camera system, and compares performance to typical broadband camera systems.

  2. Cognition and aided speech recognition in noise: specific role for cognitive factors following nine-week experience with adjusted compression settings in hearing aids.

    PubMed

    Rudner, Mary; Foo, Catharina; Rönnberg, Jerker; Lunner, Thomas

    2009-10-01

    The working memory model for Ease of Language Understanding (ELU) proposes that language understanding under taxing conditions is related to explicit cognitive capacity. We refer to this as the mismatch hypothesis, since phonological representations based on the processing of speech under established conditions may not be accessed so readily when input conditions change and a match becomes problematic. Then, cognitive capacity requirements may differ from those used for processing speech hitherto. In the present study, we tested this hypothesis by investigating the relationship between aided speech recognition in noise and cognitive capacity in experienced hearing aid users when there was either a match or mismatch between processed speech input and established phonological representations. The settings in the existing digital hearing aids of the participants were adjusted to one of two different compression settings which processed the speech signal in qualitatively different ways ("fast" or "slow"). Testing took place after a 9-week period of experience with the new setting. Speech recognition was tested under different noise conditions and with match or mismatch (i.e. alternative compression setting) manipulations of the input signal. Individual cognitive capacity was measured using a reading span test and a letter monitoring test. Reading span, a reliable measure of explicit cognitive capacity, predicted speech recognition performance under mismatch conditions when processed input was incongruent with recently established phonological representations, due to the specific hearing aid setting. Cognitive measures were not main predictors of performance under match conditions. These findings are in line with the ELU model.

  3. Dual Function of NRP1 in Axon Guidance and Subcellular Target Recognition in Cerebellum.

    PubMed

    Telley, Ludovic; Cadilhac, Christelle; Cioni, Jean-Michel; Saywell, Veronique; Jahannault-Talignani, Céline; Huettl, Rosa E; Sarrailh-Faivre, Catherine; Dayer, Alexandre; Huber, Andrea B; Ango, Fabrice

    2016-09-21

    Subcellular target recognition in the CNS is the culmination of a multiple-step program including axon guidance, target recognition, and synaptogenesis. In cerebellum, basket cells (BCs) innervate the soma and axon initial segment (AIS) of Purkinje cells (PCs) to form the pinceau synapse, but the underlying mechanisms remain incompletely understood. Here, we demonstrate that neuropilin-1 (NRP1), a Semaphorin receptor expressed in BCs, controls both axonal guidance and subcellular target recognition. We show that loss of Semaphorin 3A function or specific deletion of NRP1 in BCs alters the stereotyped organization of BC axon and impairs pinceau synapse formation. Further, we identified NRP1 as a trans-synaptic binding partner of the cell adhesion molecule neurofascin-186 (NF186) expressed in the PC AIS during pinceau synapse formation. These findings identify a dual function of NRP1 in both axon guidance and subcellular target recognition in the construction of GABAergic circuitry. PMID:27618676

  4. Nonimmunoglobulin target loci of activation-induced cytidine deaminase (AID) share unique features with immunoglobulin genes

    PubMed Central

    Kato, Lucia; Begum, Nasim A.; Burroughs, A. Maxwell; Doi, Tomomitsu; Kawai, Jun; Daub, Carsten O.; Kawaguchi, Takahisa; Matsuda, Fumihiko; Hayashizaki, Yoshihide; Honjo, Tasuku

    2012-01-01

    Activation-induced cytidine deaminase (AID) is required for both somatic hypermutation and class-switch recombination in activated B cells. AID is also known to target nonimmunoglobulin genes and introduce mutations or chromosomal translocations, eventually causing tumors. To identify as-yet-unknown AID targets, we screened early AID-induced DNA breaks by using two independent genome-wide approaches. Along with known AID targets, this screen identified a set of unique genes (SNHG3, MALAT1, BCL7A, and CUX1) and confirmed that these loci accumulated mutations as frequently as Ig locus after AID activation. Moreover, these genes share three important characteristics with the Ig gene: translocations in tumors, repetitive sequences, and the epigenetic modification of chromatin by H3K4 trimethylation in the vicinity of cleavage sites. PMID:22308462

  5. Nonimmunoglobulin target loci of activation-induced cytidine deaminase (AID) share unique features with immunoglobulin genes.

    PubMed

    Kato, Lucia; Begum, Nasim A; Burroughs, A Maxwell; Doi, Tomomitsu; Kawai, Jun; Daub, Carsten O; Kawaguchi, Takahisa; Matsuda, Fumihiko; Hayashizaki, Yoshihide; Honjo, Tasuku

    2012-02-14

    Activation-induced cytidine deaminase (AID) is required for both somatic hypermutation and class-switch recombination in activated B cells. AID is also known to target nonimmunoglobulin genes and introduce mutations or chromosomal translocations, eventually causing tumors. To identify as-yet-unknown AID targets, we screened early AID-induced DNA breaks by using two independent genome-wide approaches. Along with known AID targets, this screen identified a set of unique genes (SNHG3, MALAT1, BCL7A, and CUX1) and confirmed that these loci accumulated mutations as frequently as Ig locus after AID activation. Moreover, these genes share three important characteristics with the Ig gene: translocations in tumors, repetitive sequences, and the epigenetic modification of chromatin by H3K4 trimethylation in the vicinity of cleavage sites.

  6. Immune recognition of AIDS virus antigens by human and murine cytotoxic T lymphocytes.

    PubMed

    Langlade-Demoyen, P; Michel, F; Hoffenbach, A; Vilmer, E; Dadaglio, G; Garicia-Pons, F; Mayaud, C; Autran, B; Wain-Hobson, S; Plata, F

    1988-09-15

    The CTL response to HIV was analyzed in humans and in mice. By using a novel and strictly autologous lymphocyte culture system, human CTL lines were established with PBL from seropositive asymptomatic donors and from patients suffering from AIDS or presenting AIDS-related complex. CTL from HLA-A2 donors recognize and kill murine P815 mastocytoma cells doubly transfected with the human HLA-A2 gene and the HIV env gene; they also kill HLA-compatible human macrophages infected with HIV. CTL specific for the HIV env Ag were also generated in BALB/c mice by immunization with syngeneic murine cells transfected with the HIV env gene. Human and murine HIV-immune CTL populations belong to the CD8 subset of T lymphocytes and are restricted by class I HLA or H-2 transplantation Ag, respectively, in the recognition of HIV env Ag. The two different experimental systems presented here can be used to study CD8 lymphocyte immunity against HIV. The murine model of CTL immunity offers the additional advantage of avoiding the manipulation of infectious virus isolates.

  7. Struggling with AIDS in South Africa: the space of the everyday as a field of recognition.

    PubMed

    Le Marcis, Frédéric

    2012-12-01

    The space of volunteering is often seen as a place for rebuilding a world for individuals for whom life has been destroyed by the discovery of AIDS infection. People living with AIDS get involved in HIV support groups, become volunteers, and take care for each other. Without denying the reality of these processes leading to a "positive life" this article questions narratives of the transformation of the self-implied in the "caring for other" logic and argues that other spheres of life, less discernable because inscribed in the ordinary and in the intimacy of domestic life are at least as important as the involvement in biomedical care. The limits of voluntary work is highlighted and contrasted with a presentation of how life, love and affection is reconfigured within everyday life, leading to a consideration of people's struggles to build spaces of recognition. The argument of this article is built on a three year ethnography (2001-04) carried out in Soweto and Alexandra townships (South Africa). PMID:23361881

  8. Shape-and-motion-fused multiple flying target recognition and tracking

    NASA Astrophysics Data System (ADS)

    Kovács, Levente; Utasi, Ákos

    2010-04-01

    This paper presents an automatic approach for camera/image based detection, recognition and tracking of flying objects (planes, missiles, etc.). The method detects appearing objects, and recognizes re-appearing targets. It uses a feature-based statistical modeling approach (e.g. HMM) for motion-based recognition, and an image feature (e.g. shape) based indexed database of pre-trained object classes, suitable for recognition on known and alerting on unknown objects. The method can be used for detection of flying objects, recognition of the same object category through multiple views/cameras and signal on unusual motions and shape appearances.

  9. A Comparison of Two Flashcard Drill Methods Targeting Word Recognition

    ERIC Educational Resources Information Center

    Volpe, Robert J.; Mule, Christina M.; Briesch, Amy M.; Joseph, Laurice M.; Burns, Matthew K.

    2011-01-01

    Traditional drill and practice (TD) and incremental rehearsal (IR) are two flashcard drill instructional methods previously noted to improve word recognition. The current study sought to compare the effectiveness and efficiency of these two methods, as assessed by next day retention assessments, under 2 conditions (i.e., opportunities to respond…

  10. The effect of hearing aid bandwidth on speech recognition performance of listeners using a cochlear implant and contralateral hearing aid (bimodal hearing)

    PubMed Central

    Neuman, Arlene C.; Svirsky, Mario A.

    2013-01-01

    Objectives The purpose of this study was to determine how the bandwidth of the hearing aid (HA) fitting affects bimodal speech recognition of listeners with a cochlear implant (CI) in one ear and severe-to-profound hearing loss in the unimplanted ear (but with residual hearing sufficient for wideband amplification using NAL-RP prescriptive guidelines; unaided thresholds no poorer than 95 dB HL through 2000 Hz). Design Recognition of sentence material in quiet and in noise was measured with the CI alone and with CI plus HA as the amplification provided by the hearing aid in the high and mid-frequency regions was systematically reduced from the wideband condition (NAL-RP prescription). Modified bandwidths included upper frequency cutoffs of 2,000, 1,000 or 500 Hz. Results On average, significant bimodal benefit was obtained when the hearing aid provided amplification at all frequencies with aidable residual hearing. Limiting the hearing aid bandwidth to only low frequency amplification (below 1000 Hz) did not yield significant improvements in performance over listening with the CI alone. Conclusion These data suggest the importance of providing amplification across as wide a frequency region as permitted by audiometric thresholds in the hearing aid used by bimodal users. PMID:23632973

  11. Kernel sparse coding method for automatic target recognition in infrared imagery using covariance descriptor

    NASA Astrophysics Data System (ADS)

    Yang, Chunwei; Yao, Junping; Sun, Dawei; Wang, Shicheng; Liu, Huaping

    2016-05-01

    Automatic target recognition in infrared imagery is a challenging problem. In this paper, a kernel sparse coding method for infrared target recognition using covariance descriptor is proposed. First, covariance descriptor combining gray intensity and gradient information of the infrared target is extracted as a feature representation. Then, due to the reason that covariance descriptor lies in non-Euclidean manifold, kernel sparse coding theory is used to solve this problem. We verify the efficacy of the proposed algorithm in terms of the confusion matrices on the real images consisting of seven categories of infrared vehicle targets.

  12. Combining synthetic image generation and AI to aid automatic target recognizers

    NASA Astrophysics Data System (ADS)

    Keller, R.; Juarez, J.; Prater, M.; Balaban, T.

    1987-01-01

    The user-friendly, Band-Independent Signature Prediction (BISP) model has been developed for the recognition of real-world targets in complex backgrounds and under variable environmental conditions and operating states, through the use of a signature-prediction capability that can be used in conjunction with a natural language description of the recognition context to determine both the features and the feature strengths for the specified context. BISP's signature-prediction capability can be used to design a context-adaptive target recognizer that is based on either classical pattern recognition principles or on more advanced but less mature learning networks akin to those of emerging 'neurocomputers'.

  13. Fearful contextual expression impairs the encoding and recognition of target faces: an ERP study

    PubMed Central

    Lin, Huiyan; Schulz, Claudia; Straube, Thomas

    2015-01-01

    Previous event-related potential (ERP) studies have shown that the N170 to faces is modulated by the emotion of the face and its context. However, it is unclear how the encoding of emotional target faces as reflected in the N170 is modulated by the preceding contextual facial expression when temporal onset and identity of target faces are unpredictable. In addition, no study as yet has investigated whether contextual facial expression modulates later recognition of target faces. To address these issues, participants in the present study were asked to identify target faces (fearful or neutral) that were presented after a sequence of fearful or neutral contextual faces. The number of sequential contextual faces was random and contextual and target faces were of different identities so that temporal onset and identity of target faces were unpredictable. Electroencephalography (EEG) data was recorded during the encoding phase. Subsequently, participants had to perform an unexpected old/new recognition task in which target face identities were presented in either the encoded or the non-encoded expression. ERP data showed a reduced N170 to target faces in fearful as compared to neutral context regardless of target facial expression. In the later recognition phase, recognition rates were reduced for target faces in the encoded expression when they had been encountered in fearful as compared to neutral context. The present findings suggest that fearful compared to neutral contextual faces reduce the allocation of attentional resources towards target faces, which results in limited encoding and recognition of target faces. PMID:26388751

  14. Targeting the audience for AIDS messages by actual and perceived risk.

    PubMed

    Snyder, L B; Rouse, R A

    1992-01-01

    Since there are many ways to segment an audience into target groups, we suggest that a productive strategy for AIDS education is to divide the audience by their actual and perceived risk. We provide an example in which we segmented an urban U.S. sample and make suggestions as to how messages appropriate for each group can be constructed. In our sample, the "unthreatened" accurately assessed their low risk of AIDS, and showed high knowledge and tolerance rates. The "panicked," who included more women and Hispanics, inaccurately thought themselves at high risk because of misunderstandings about the causes of AIDS, and showed more intolerance of people with AIDS. "Deniers" continued to have multiple sexual partners and take precautions irregularly, despite seeing AIDS as a social problem and having more education and AIDS knowledge. In contrast, "gamblers" recognized their higher risk of AIDS and were most likely to have taken some action, although not enough to prevent sexual transmission of the HIV virus.

  15. Modern prescription theory and application: realistic expectations for speech recognition with hearing AIDS.

    PubMed

    Johnson, Earl E

    2013-01-01

    A major decision at the time of hearing aid fitting and dispensing is the amount of amplification to provide listeners (both adult and pediatric populations) for the appropriate compensation of sensorineural hearing impairment across a range of frequencies (e.g., 160-10000 Hz) and input levels (e.g., 50-75 dB sound pressure level). This article describes modern prescription theory for hearing aids within the context of a risk versus return trade-off and efficient frontier analyses. The expected return of amplification recommendations (i.e., generic prescriptions such as National Acoustic Laboratories-Non-Linear 2, NAL-NL2, and Desired Sensation Level Multiple Input/Output, DSL m[i/o]) for the Speech Intelligibility Index (SII) and high-frequency audibility were traded against a potential risk (i.e., loudness). The modeled performance of each prescription was compared one with another and with the efficient frontier of normal hearing sensitivity (i.e., a reference point for the most return with the least risk). For the pediatric population, NAL-NL2 was more efficient for SII, while DSL m[i/o] was more efficient for high-frequency audibility. For the adult population, NAL-NL2 was more efficient for SII, while the two prescriptions were similar with regard to high-frequency audibility. In terms of absolute return (i.e., not considering the risk of loudness), however, DSL m[i/o] prescribed more outright high-frequency audibility than NAL-NL2 for either aged population, particularly, as hearing loss increased. Given the principles and demonstrated accuracy of desensitization (reduced utility of audibility with increasing hearing loss) observed at the group level, additional high-frequency audibility beyond that of NAL-NL2 is not expected to make further contributions to speech intelligibility (recognition) for the average listener. PMID:24253361

  16. Modern Prescription Theory and Application: Realistic Expectations for Speech Recognition With Hearing Aids

    PubMed Central

    2013-01-01

    A major decision at the time of hearing aid fitting and dispensing is the amount of amplification to provide listeners (both adult and pediatric populations) for the appropriate compensation of sensorineural hearing impairment across a range of frequencies (e.g., 160–10000 Hz) and input levels (e.g., 50–75 dB sound pressure level). This article describes modern prescription theory for hearing aids within the context of a risk versus return trade-off and efficient frontier analyses. The expected return of amplification recommendations (i.e., generic prescriptions such as National Acoustic Laboratories—Non-Linear 2, NAL-NL2, and Desired Sensation Level Multiple Input/Output, DSL m[i/o]) for the Speech Intelligibility Index (SII) and high-frequency audibility were traded against a potential risk (i.e., loudness). The modeled performance of each prescription was compared one with another and with the efficient frontier of normal hearing sensitivity (i.e., a reference point for the most return with the least risk). For the pediatric population, NAL-NL2 was more efficient for SII, while DSL m[i/o] was more efficient for high-frequency audibility. For the adult population, NAL-NL2 was more efficient for SII, while the two prescriptions were similar with regard to high-frequency audibility. In terms of absolute return (i.e., not considering the risk of loudness), however, DSL m[i/o] prescribed more outright high-frequency audibility than NAL-NL2 for either aged population, particularly, as hearing loss increased. Given the principles and demonstrated accuracy of desensitization (reduced utility of audibility with increasing hearing loss) observed at the group level, additional high-frequency audibility beyond that of NAL-NL2 is not expected to make further contributions to speech intelligibility (recognition) for the average listener. PMID:24253361

  17. Efficient AID targeting of switch regions is not sufficient for optimal class switch recombination.

    PubMed

    Bonaud, Amélie; Lechouane, Fabien; Le Noir, Sandrine; Monestier, Olivier; Cogné, Michel; Sirac, Christophe

    2015-07-06

    Antibody affinity maturation relies on activation-induced cytidine deaminase (AID)-dependent somatic hypermutation (SHM) of immunoglobulin (Ig) loci. Class switch recombination (CSR) can in parallel occur between AID-targeted, transcribed, spliced and repetitive switch (S) regions. AID thus initiates not only mutations but also double-strand breaks (DSBs). What governs the choice between those two outcomes remains uncertain. Here we explore whether insertion of transcribed intronic S regions in a locus (Igκ) strongly recruiting AID is sufficient for efficient CSR. Although strongly targeted by AID and carrying internal deletions, the knocked-in S regions only undergo rare CSR-like events. This model confirms S regions as exquisite SHM targets, extending AID activity far from transcription initiation sites, and shows that such spliced and repetitive AID targets are not sufficient by themselves for CSR. Beyond transcription and AID recruitment, additional IgH elements are thus needed for CSR, restricting this hazardous gene remodelling to IgH loci.

  18. Interplay between Target Sequences and Repair Pathways Determines Distinct Outcomes of AID-Initiated Lesions.

    PubMed

    Chen, Zhangguo; Eder, Maxwell D; Elos, Mihret T; Viboolsittiseri, Sawanee S; Chen, Xiaomi; Wang, Jing H

    2016-03-01

    Activation-induced deaminase (AID) functions by deaminating cytosines and causing U:G mismatches, a rate-limiting step of Ab gene diversification. However, precise mechanisms regulating AID deamination frequency remain incompletely understood. Moreover, it is not known whether different sequence contexts influence the preferential access of mismatch repair or uracil glycosylase (UNG) to AID-initiated U:G mismatches. In this study, we employed two knock-in models to directly compare the mutability of core Sμ and VDJ exon sequences and their ability to regulate AID deamination and subsequent repair process. We find that the switch (S) region is a much more efficient AID deamination target than the V region. Igh locus AID-initiated lesions are processed by error-free and error-prone repair. S region U:G mismatches are preferentially accessed by UNG, leading to more UNG-dependent deletions, enhanced by mismatch repair deficiency. V region mutation hotspots are largely determined by AID deamination. Recurrent and conserved S region motifs potentially function as spacers between AID deamination hotspots. We conclude that the pattern of mutation hotspots and DNA break generation is influenced by sequence-intrinsic properties, which regulate AID deamination and affect the preferential access of downstream repair. Our studies reveal an evolutionarily conserved role for substrate sequences in regulating Ab gene diversity and AID targeting specificity.

  19. Convergent transcription at intragenic super-enhancers targets AID-initiated genomic instability.

    PubMed

    Meng, Fei-Long; Du, Zhou; Federation, Alexander; Hu, Jiazhi; Wang, Qiao; Kieffer-Kwon, Kyong-Rim; Meyers, Robin M; Amor, Corina; Wasserman, Caitlyn R; Neuberg, Donna; Casellas, Rafael; Nussenzweig, Michel C; Bradner, James E; Liu, X Shirley; Alt, Frederick W

    2014-12-18

    Activation-induced cytidine deaminase (AID) initiates both somatic hypermutation (SHM) for antibody affinity maturation and DNA breakage for antibody class switch recombination (CSR) via transcription-dependent cytidine deamination of single-stranded DNA targets. Though largely specific for immunoglobulin genes, AID also acts on a limited set of off-targets, generating oncogenic translocations and mutations that contribute to B cell lymphoma. How AID is recruited to off-targets has been a long-standing mystery. Based on deep GRO-seq studies of mouse and human B lineage cells activated for CSR or SHM, we report that most robust AID off-target translocations occur within highly focal regions of target genes in which sense and antisense transcription converge. Moreover, we found that such AID-targeting "convergent" transcription arises from antisense transcription that emanates from super-enhancers within sense transcribed gene bodies. Our findings provide an explanation for AID off-targeting to a small subset of mostly lineage-specific genes in activated B cells.

  20. Properdin: New roles in pattern recognition and target clearance

    PubMed Central

    Kemper, Claudia; Hourcade, Dennis E.

    2008-01-01

    Properdin was first described over 50 years ago by Louis Pillemer and his collaborators as a vital component of an antibody-independent complement activation pathway. In the 1970’s properdin was shown to be a stabilizing component of the alternative pathway convertases, the central enzymes of the complement cascade. Recently we have reported that properdin can also bind to target cells and microbes, provide a platform for convertase assembly and function, and promote target phagocytosis. Evidence is emerging that suggests that properdin interacts with a network of target ligands, phagocyte receptors, and serum regulators. Here we review the new findings and their possible implications. PMID:18692243

  1. Structural basis of diverse membrane target recognitions by ankyrins.

    PubMed

    Wang, Chao; Wei, Zhiyi; Chen, Keyu; Ye, Fei; Yu, Cong; Bennett, Vann; Zhang, Mingjie

    2014-01-01

    Ankyrin adaptors together with their spectrin partners coordinate diverse ion channels and cell adhesion molecules within plasma membrane domains and thereby promote physiological activities including fast signaling in the heart and nervous system. Ankyrins specifically bind to numerous membrane targets through their 24 ankyrin repeats (ANK repeats), although the mechanism for the facile and independent evolution of these interactions has not been resolved. Here we report the structures of ANK repeats in complex with an inhibitory segment from the C-terminal regulatory domain and with a sodium channel Nav1.2 peptide, respectively, showing that the extended, extremely conserved inner groove spanning the entire ANK repeat solenoid contains multiple target binding sites capable of accommodating target proteins with very diverse sequences via combinatorial usage of these sites. These structures establish a framework for understanding the evolution of ankyrins' membrane targets, with implications for other proteins containing extended ANK repeat domains. PMID:25383926

  2. Advances in Doppler recognition for ground moving target indication

    NASA Astrophysics Data System (ADS)

    Kealey, Paul G.; Jahangir, Mohammed

    2006-05-01

    Ground Moving Target Indication (GMTI) radar provides a day/night, all-weather, wide-area surveillance capability to detect moving vehicles and personnel. Current GMTI radar sensors are limited to only detecting and tracking targets. The exploitation of GMTI data would be greatly enhanced by a capability to recognize accurately the detections as significant classes of target. Doppler classification exploits the differential internal motion of targets, e.g. due to the tracks, limbs and rotors. Recently, the QinetiQ Bayesian Doppler classifier has been extended to include a helicopter class in addition to wheeled, tracked and personnel classes. This paper presents the performance for these four classes using a traditional low-resolution GMTI surveillance waveform with an experimental radar system. We have determined the utility of an "unknown output decision" for enhancing the accuracy of the declared target classes. A confidence method has been derived, using a threshold of the difference in certainties, to assign uncertain classifications into an "unknown class". The trade-off between fraction of targets declared and accuracy of the classifier has been measured. To determine the operating envelope of a Doppler classification algorithm requires a detailed understanding of the Signal-to-Noise Ratio (SNR) performance of the algorithm. In this study the SNR dependence of the QinetiQ classifier has been determined.

  3. Based on momentum method BP neural network in the target recognition research and application

    NASA Astrophysics Data System (ADS)

    Zhang, Xue-feng; Gao, Yu-bin

    2011-08-01

    Target recognition is measured by treating target existing knowledge to judge, analyze, and thus the process of target identification. Using anti-vibration lateral shearing interferometer to get the interference fringe for the spectrum information of measurement target, and the system can get the target by spectrum identification algorithm. By the condition that interferometer's length isn't changed, the system was optimized by momentum BP Neural Network algorithm in the separating mixed spectrum process, therefore it could improve the probability of camouflage target recognition. The spectrum information was calculated by the fringes, to getting the mixed spectrum data. The absorption spectrum was in the hidden layer, and the system obtained every kinds of characteristic spectrum from mixed spectrum by the momentum BP Neural Network. Experiments showed that it collected mixed spectrum of background form different distances and different surface, and made them to the initial spectrum information. The test target was a board that it's surface was made to four kinds, and there was no paint (A), brushing camouflage paint of military green (B), brushing camouflage paint of irregular shape (C) and brushing camouflage paint of irregular box (D). The mixed spectrum was obtained from the anti-vibration lateral shearing interferometer, while the recognition probability for non-camouflage target were above 90.0% by the traditional algorithm and the momentum BP neural network algorithm, but the recognition probability for camouflage target was 85.6% by momentum BP neural network algorithm, better than 41.5% by the traditional algorithm, so it proved that the algorithm could improve the recognition probability for camouflage target effectively.

  4. Target recognitions in multiple-camera closed-circuit television using color constancy

    NASA Astrophysics Data System (ADS)

    Soori, Umair; Yuen, Peter; Han, Ji Wen; Ibrahim, Izzati; Chen, Wentao; Hong, Kan; Merfort, Christian; James, David; Richardson, Mark

    2013-04-01

    People tracking in crowded scenes from closed-circuit television (CCTV) footage has been a popular and challenging task in computer vision. Due to the limited spatial resolution in the CCTV footage, the color of people's dress may offer an alternative feature for their recognition and tracking. However, there are many factors, such as variable illumination conditions, viewing angles, and camera calibration, that may induce illusive modification of intrinsic color signatures of the target. Our objective is to recognize and track targets in multiple camera views using color as the detection feature, and to understand if a color constancy (CC) approach may help to reduce these color illusions due to illumination and camera artifacts and thereby improve target recognition performance. We have tested a number of CC algorithms using various color descriptors to assess the efficiency of target recognition from a real multicamera Imagery Library for Intelligent Detection Systems (i-LIDS) data set. Various classifiers have been used for target detection, and the figure of merit to assess the efficiency of target recognition is achieved through the area under the receiver operating characteristics (AUROC). We have proposed two modifications of luminance-based CC algorithms: one with a color transfer mechanism and the other using a pixel-wise sigmoid function for an adaptive dynamic range compression, a method termed enhanced luminance reflectance CC (ELRCC). We found that both algorithms improve the efficiency of target recognitions substantially better than that of the raw data without CC treatment, and in some cases the ELRCC improves target tracking by over 100% within the AUROC assessment metric. The performance of the ELRCC has been assessed over 10 selected targets from three different camera views of the i-LIDS footage, and the averaged target recognition efficiency over all these targets is found to be improved by about 54% in AUROC after the data are processed by

  5. Pattern-Recognition System for Approaching a Known Target

    NASA Technical Reports Server (NTRS)

    Huntsberger, Terrance; Cheng, Yang

    2008-01-01

    A closed-loop pattern-recognition system is designed to provide guidance for maneuvering a small exploratory robotic vehicle (rover) on Mars to return to a landed spacecraft to deliver soil and rock samples that the spacecraft would subsequently bring back to Earth. The system could be adapted to terrestrial use in guiding mobile robots to approach known structures that humans could not approach safely, for such purposes as reconnaissance in military or law-enforcement applications, terrestrial scientific exploration, and removal of explosive or other hazardous items. The system has been demonstrated in experiments in which the Field Integrated Design and Operations (FIDO) rover (a prototype Mars rover equipped with a video camera for guidance) is made to return to a mockup of Mars-lander spacecraft. The FIDO rover camera autonomously acquires an image of the lander from a distance of 125 m in an outdoor environment. Then under guidance by an algorithm that performs fusion of multiple line and texture features in digitized images acquired by the camera, the rover traverses the intervening terrain, using features derived from images of the lander truss structure. Then by use of precise pattern matching for determining the position and orientation of the rover relative to the lander, the rover aligns itself with the bottom of ramps extending from the lander, in preparation for climbing the ramps to deliver samples to the lander. The most innovative aspect of the system is a set of pattern-recognition algorithms that govern a three-phase visual-guidance sequence for approaching the lander. During the first phase, a multifeature fusion algorithm integrates the outputs of a horizontal-line-detection algorithm and a wavelet-transform-based visual-area-of-interest algorithm for detecting the lander from a significant distance. The horizontal-line-detection algorithm is used to determine candidate lander locations based on detection of a horizontal deck that is part of the

  6. Target recognition in passive terahertz image of human body

    NASA Astrophysics Data System (ADS)

    Zhao, Ran; Zhao, Yuan-meng; Deng, Chao; Zhang, Cun-lin; Li, Yue

    2014-11-01

    THz radiation can penetrate through many nonpolar dielectric materials and can be used for nondestructive/noninvasive sensing and imaging of targets under nonpolar, nonmetallic covers or containers. Thus using THz systems to "see through" concealing barriers (i.e. packaging, corrugated cardboard, clothing) has been proposed as a new security screening method. Objects that can be detected by THz include concealed weapons, explosives, and chemical agents under clothing. Passive THz imaging system can detect THz wave from human body without transmit any electromagnetic wave, and the suspicious objects will become visible because the THz wave is blocked by this items. We can find out whether or not someone is carrying dangerous objects through this image. In this paper, the THz image enhancement, segmentation and contour extraction algorithms were studied to achieve effective target image detection. First, the terahertz images are enhanced and their grayscales are stretched. Then we apply global threshold segmentation to extract the target, and finally the targets are marked on the image. Experimental results showed that the algorithm proposed in this paper can extract and mark targets effectively, so that people can identify suspicious objects under clothing quickly. The algorithm can significantly improve the usefulness of the terahertz security apparatus.

  7. Testing of a Composite Wavelet Filter to Enhance Automated Target Recognition in SONAR

    NASA Technical Reports Server (NTRS)

    Chiang, Jeffrey N.

    2011-01-01

    Automated Target Recognition (ATR) systems aim to automate target detection, recognition, and tracking. The current project applies a JPL ATR system to low resolution SONAR and camera videos taken from Unmanned Underwater Vehicles (UUVs). These SONAR images are inherently noisy and difficult to interpret, and pictures taken underwater are unreliable due to murkiness and inconsistent lighting. The ATR system breaks target recognition into three stages: 1) Videos of both SONAR and camera footage are broken into frames and preprocessed to enhance images and detect Regions of Interest (ROIs). 2) Features are extracted from these ROIs in preparation for classification. 3) ROIs are classified as true or false positives using a standard Neural Network based on the extracted features. Several preprocessing, feature extraction, and training methods are tested and discussed in this report.

  8. Field testing of a 3D automatic target recognition and pose estimation algorithm

    NASA Astrophysics Data System (ADS)

    Ruel, Stephane; English, Chad E.; Melo, Len; Berube, Andrew; Aikman, Doug; Deslauriers, Adam M.; Church, Philip M.; Maheux, Jean

    2004-09-01

    Neptec Design Group Ltd. has developed a 3D Automatic Target Recognition (ATR) and pose estimation technology demonstrator in partnership with the Canadian DND. The system prototype was deployed for field testing at Defence Research and Development Canada (DRDC)-Valcartier. This paper discusses the performance of the developed algorithm using 3D scans acquired with an imaging LIDAR. 3D models of civilian and military vehicles were built using scans acquired with a triangulation laser scanner. The models were then used to generate a knowledge base for the recognition algorithm. A commercial imaging LIDAR was used to acquire test scans of the target vehicles with varying range, pose and degree of occlusion. Recognition and pose estimation results are presented for at least 4 different poses of each vehicle at each test range. Results obtained with targets partially occluded by an artificial plane, vegetation and military camouflage netting are also presented. Finally, future operational considerations are discussed.

  9. Structural basis of diverse membrane target recognitions by ankyrins

    PubMed Central

    Wang, Chao; Wei, Zhiyi; Chen, Keyu; Ye, Fei; Yu, Cong; Bennett, Vann; Zhang, Mingjie

    2014-01-01

    Ankyrin adaptors together with their spectrin partners coordinate diverse ion channels and cell adhesion molecules within plasma membrane domains and thereby promote physiological activities including fast signaling in the heart and nervous system. Ankyrins specifically bind to numerous membrane targets through their 24 ankyrin repeats (ANK repeats), although the mechanism for the facile and independent evolution of these interactions has not been resolved. Here we report the structures of ANK repeats in complex with an inhibitory segment from the C-terminal regulatory domain and with a sodium channel Nav1.2 peptide, respectively, showing that the extended, extremely conserved inner groove spanning the entire ANK repeat solenoid contains multiple target binding sites capable of accommodating target proteins with very diverse sequences via combinatorial usage of these sites. These structures establish a framework for understanding the evolution of ankyrins' membrane targets, with implications for other proteins containing extended ANK repeat domains. DOI: http://dx.doi.org/10.7554/eLife.04353.001 PMID:25383926

  10. Target Site Recognition by a Diversity-Generating Retroelement

    PubMed Central

    Guo, Huatao; Tse, Longping V.; Nieh, Angela W.; Czornyj, Elizabeth; Williams, Steven; Oukil, Sabrina; Liu, Vincent B.; Miller, Jeff F.

    2011-01-01

    Diversity-generating retroelements (DGRs) are in vivo sequence diversification machines that are widely distributed in bacterial, phage, and plasmid genomes. They function to introduce vast amounts of targeted diversity into protein-encoding DNA sequences via mutagenic homing. Adenine residues are converted to random nucleotides in a retrotransposition process from a donor template repeat (TR) to a recipient variable repeat (VR). Using the Bordetella bacteriophage BPP-1 element as a prototype, we have characterized requirements for DGR target site function. Although sequences upstream of VR are dispensable, a 24 bp sequence immediately downstream of VR, which contains short inverted repeats, is required for efficient retrohoming. The inverted repeats form a hairpin or cruciform structure and mutational analysis demonstrated that, while the structure of the stem is important, its sequence can vary. In contrast, the loop has a sequence-dependent function. Structure-specific nuclease digestion confirmed the existence of a DNA hairpin/cruciform, and marker coconversion assays demonstrated that it influences the efficiency, but not the site of cDNA integration. Comparisons with other phage DGRs suggested that similar structures are a conserved feature of target sequences. Using a kanamycin resistance determinant as a reporter, we found that transplantation of the IMH and hairpin/cruciform-forming region was sufficient to target the DGR diversification machinery to a heterologous gene. In addition to furthering our understanding of DGR retrohoming, our results suggest that DGRs may provide unique tools for directed protein evolution via in vivo DNA diversification. PMID:22194701

  11. Target site recognition by a diversity-generating retroelement.

    PubMed

    Guo, Huatao; Tse, Longping V; Nieh, Angela W; Czornyj, Elizabeth; Williams, Steven; Oukil, Sabrina; Liu, Vincent B; Miller, Jeff F

    2011-12-01

    Diversity-generating retroelements (DGRs) are in vivo sequence diversification machines that are widely distributed in bacterial, phage, and plasmid genomes. They function to introduce vast amounts of targeted diversity into protein-encoding DNA sequences via mutagenic homing. Adenine residues are converted to random nucleotides in a retrotransposition process from a donor template repeat (TR) to a recipient variable repeat (VR). Using the Bordetella bacteriophage BPP-1 element as a prototype, we have characterized requirements for DGR target site function. Although sequences upstream of VR are dispensable, a 24 bp sequence immediately downstream of VR, which contains short inverted repeats, is required for efficient retrohoming. The inverted repeats form a hairpin or cruciform structure and mutational analysis demonstrated that, while the structure of the stem is important, its sequence can vary. In contrast, the loop has a sequence-dependent function. Structure-specific nuclease digestion confirmed the existence of a DNA hairpin/cruciform, and marker coconversion assays demonstrated that it influences the efficiency, but not the site of cDNA integration. Comparisons with other phage DGRs suggested that similar structures are a conserved feature of target sequences. Using a kanamycin resistance determinant as a reporter, we found that transplantation of the IMH and hairpin/cruciform-forming region was sufficient to target the DGR diversification machinery to a heterologous gene. In addition to furthering our understanding of DGR retrohoming, our results suggest that DGRs may provide unique tools for directed protein evolution via in vivo DNA diversification.

  12. Shadow and feature recognition aids for rapid image geo-registration in UAV vision system architectures

    NASA Astrophysics Data System (ADS)

    Baer, Wolfgang; Kölsch, Mathias

    2009-05-01

    The problem of real-time image geo-referencing is encountered in all vision based cognitive systems. In this paper we present a model-image feedback approach to this problem and show how it can be applied to image exploitation from Unmanned Arial Vehicle (UAV) vision systems. By calculating reference images from a known terrain database, using a novel ray trace algorithm, we are able to eliminate foreshortening, elevation, and lighting distortions, introduce registration aids and reduce the geo-referencing problem to a linear transformation search over the two dimensional image space. A method for shadow calculation that maintains real-time performance is also presented. The paper then discusses the implementation of our model-image feedback approach in the Perspective View Nascent Technology (PVNT) software package and provides sample results from UAV mission control and target mensuration experiments conducted at China Lake and Camp Roberts, California.

  13. An improved cortex-like neuromorphic system for target recognitions

    NASA Astrophysics Data System (ADS)

    Tsitiridis, Aristeidis; Yuen, Peter; Hong, Kan; Chen, Tong; Ibrahim, Izzati; Jackman, James; James, David; Richardson, Mark

    2010-10-01

    This paper reports on the enhancement of biologically-inspired machine vision through a rotation invariance mechanism. Research over the years has suggested that rotation invariance is one of the fundamental generic elements of object constancy, a known generic visual ability of the human brain. Cortex-like vision unlike conventional pixel based machine vision is achieved by mimicking neuromorphic mechanisms of the primates' brain. In this preliminary study, rotation invariance is implemented through histograms from Gabor features of an object. The performance of rotation invariance in the neuromorphic algorithm is assessed by the classification accuracies of a test data set which consists of image objects in five different orientations. It is found that a much more consistent classification result over these five different oriented data sets has been achieved by the integrated rotation invariance neuromorphic algorithm compared to the one without. In addition, the issue of varying aspect ratios of input images to these models is also addressed, in an attempt to create a robust algorithm against a wider variability of input data. The extension of the present achievement is to improve the recognition accuracies while incorporating it to a series of different real-world scenarios which would challenge the approach accordingly.

  14. Automatic target recognition algorithm based on statistical dispersion of infrared multispectral image

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Cao, Le-lin; Wu, Chun-feng; Hou, Qing-yu

    2009-07-01

    A novel automatic target recognition algorithm based on statistical dispersion of infrared multispectral images(SDOIMI) is proposed. Firstly, infrared multispectral characteristic matrix of the scenario is constructed based on infrared multispectral characteristic information (such as radiation intensity and spectral distribution etc.) of targets, background and decoys. Then the infrared multispectral characteristic matrix of targets is reconstructed after segmenting image by maximum distance method and fusing spatial and spectral information. Finally, an statistical dispersion of infrared multispectral images(SDOIMI) recognition criteria is formulated in terms of spectral radiation difference of interesting targets. In simulation, nine sub-bands multispectral images of real ship target and shipborne aerosol infrared decoy modulated by laser simulating ship geometry appearance are obtained via using spectral radiation curves. Digital simulation experiment result verifies that the algorithm is effective and feasible.

  15. Application of support vector machine and quantum genetic algorithm in infrared target recognition

    NASA Astrophysics Data System (ADS)

    Wang, Hongliang; Huang, Yangwen; Ding, Haifei

    2010-08-01

    In this paper, a kind of classifier based on support vector machine (SVM) is designed for infrared target recognition. In allusion to the problem how to choose kernel parameter and error penalty factor, quantum genetic algorithm (QGA) is used to optimize the parameters of SVM model, it overcomes the shortcoming of determining its parameters after trial and error in the past. Classification experiments of infrared target features extracted by this method show that the convergence speed is fast and the rate of accurate recognition is high.

  16. Optimization of OT-MACH Filter Generation for Target Recognition

    NASA Technical Reports Server (NTRS)

    Johnson, Oliver C.; Edens, Weston; Lu, Thomas T.; Chao, Tien-Hsin

    2009-01-01

    An automatic Optimum Trade-off Maximum Average Correlation Height (OT-MACH) filter generator for use in a gray-scale optical correlator (GOC) has been developed for improved target detection at JPL. While the OT-MACH filter has been shown to be an optimal filter for target detection, actually solving for the optimum is too computationally intensive for multiple targets. Instead, an adaptive step gradient descent method was tested to iteratively optimize the three OT-MACH parameters, alpha, beta, and gamma. The feedback for the gradient descent method was a composite of the performance measures, correlation peak height and peak to side lobe ratio. The automated method generated and tested multiple filters in order to approach the optimal filter quicker and more reliably than the current manual method. Initial usage and testing has shown preliminary success at finding an approximation of the optimal filter, in terms of alpha, beta, gamma values. This corresponded to a substantial improvement in detection performance where the true positive rate increased for the same average false positives per image.

  17. Relating hearing loss and executive functions to hearing aid users' preference for, and speech recognition with, different combinations of binaural noise reduction and microphone directionality

    PubMed Central

    Neher, Tobias

    2014-01-01

    Knowledge of how executive functions relate to preferred hearing aid (HA) processing is sparse and seemingly inconsistent with related knowledge for speech recognition outcomes. This study thus aimed to find out if (1) performance on a measure of reading span (RS) is related to preferred binaural noise reduction (NR) strength, (2) similar relations exist for two different, non-verbal measures of executive function, (3) pure-tone average hearing loss (PTA), signal-to-noise ratio (SNR), and microphone directionality (DIR) also influence preferred NR strength, and (4) preference and speech recognition outcomes are similar. Sixty elderly HA users took part. Six HA conditions consisting of omnidirectional or cardioid microphones followed by inactive, moderate, or strong binaural NR as well as linear amplification were tested. Outcome was assessed at fixed SNRs using headphone simulations of a frontal target talker in a busy cafeteria. Analyses showed positive effects of active NR and DIR on preference, and negative and positive effects of, respectively, strong NR and DIR on speech recognition. Also, while moderate NR was the most preferred NR setting overall, preference for strong NR increased with SNR. No relation between RS and preference was found. However, larger PTA was related to weaker preference for inactive NR and stronger preference for strong NR for both microphone modes. Equivalent (but weaker) relations between worse performance on one non-verbal measure of executive function and the HA conditions without DIR were found. For speech recognition, there were relations between HA condition, PTA, and RS, but their pattern differed from that for preference. Altogether, these results indicate that, while moderate NR works well in general, a notable proportion of HA users prefer stronger NR. Furthermore, PTA and executive functions can account for some of the variability in preference for, and speech recognition with, different binaural NR and DIR settings. PMID

  18. Pattern recognition control outperforms conventional myoelectric control in upper limb patients with targeted muscle reinnervation.

    PubMed

    Hargrove, Levi J; Lock, Blair A; Simon, Ann M

    2013-01-01

    Pattern recognition myoelectric control shows great promise as an alternative to conventional amplitude based control to control multiple degree of freedom prosthetic limbs. Many studies have reported pattern recognition classification error performances of less than 10% during offline tests; however, it remains unclear how this translates to real-time control performance. In this contribution, we compare the real-time control performances between pattern recognition and direct myoelectric control (a popular form of conventional amplitude control) for participants who had received targeted muscle reinnervation. The real-time performance was evaluated during three tasks; 1) a box and blocks task, 2) a clothespin relocation task, and 3) a block stacking task. Our results found that pattern recognition significantly outperformed direct control for all three performance tasks. Furthermore, it was found that pattern recognition was configured much quicker. The classification error of the pattern recognition systems used by the patients was found to be 16% ±(1.6%) suggesting that systems with this error rate may still provide excellent control. Finally, patients qualitatively preferred using pattern recognition control and reported the resulting control to be smoother and more consistent.

  19. Anodal tDCS targeting the right orbitofrontal cortex enhances facial expression recognition.

    PubMed

    Willis, Megan L; Murphy, Jillian M; Ridley, Nicole J; Vercammen, Ans

    2015-12-01

    The orbitofrontal cortex (OFC) has been implicated in the capacity to accurately recognise facial expressions. The aim of the current study was to determine if anodal transcranial direct current stimulation (tDCS) targeting the right OFC in healthy adults would enhance facial expression recognition, compared with a sham condition. Across two counterbalanced sessions of tDCS (i.e. anodal and sham), 20 undergraduate participants (18 female) completed a facial expression labelling task comprising angry, disgusted, fearful, happy, sad and neutral expressions, and a control (social judgement) task comprising the same expressions. Responses on the labelling task were scored for accuracy, median reaction time and overall efficiency (i.e. combined accuracy and reaction time). Anodal tDCS targeting the right OFC enhanced facial expression recognition, reflected in greater efficiency and speed of recognition across emotions, relative to the sham condition. In contrast, there was no effect of tDCS to responses on the control task. This is the first study to demonstrate that anodal tDCS targeting the right OFC boosts facial expression recognition. This finding provides a solid foundation for future research to examine the efficacy of this technique as a means to treat facial expression recognition deficits, particularly in individuals with OFC damage or dysfunction.

  20. [Research on Multi-Spectral Target Recognition System Based on the Magneto-Optical Modulation].

    PubMed

    Yan, Xiao-yan; Qin, Jian-min; Qiao, Ji-pin

    2016-03-01

    The technology of target recognition based on characteristic multi-spectrum has many advantages, such as strong detection capability and discriminating capability of target species. But there are some problems, it requires that you obtain the background spectrum as a priori knowledge, and it requires that the change of background spectrum is small with time. Thereby its application of real-time object recognition is limited in the new environment, or the complex environment. Based on magneto-optical modulation and characteristic multi-spectrum the method is designed, and the target is identified without prior access to the background spectrum. In order to achieve the function of the target information in the one acquisition time for tested, compared to conventional methods in terms of target detection, it's adaptability is better than before on the battlefield, and it is of more practical significance. Meanwhile, the magneto-optical modulator is used to suppress the interference of stray light background, thereby improving the probability of target recognition. Since the magneto-optical modulation provides incremental iterative target spectral information, therefore, even if the unknown background spectrum or background spectrum change is large, it can significantly improve the recognition accuracy of information through an iterative target spectrum. Different test targets back shimmering light intensity and background intensity values were analyzed during experiments, results showed that three targets for linearly polarized reflectance modulation is significantly stronger than the background. And it was of great influence to visible imaging target identification when measured target used camouflage color, but the system of polarization modulation type can still recognize target well. On this basis, the target range within 0.5 km x 2 km multi-wavelength characteristics of the target species were identified. When using three characteristic wavelengths, the

  1. [Research on Multi-Spectral Target Recognition System Based on the Magneto-Optical Modulation].

    PubMed

    Yan, Xiao-yan; Qin, Jian-min; Qiao, Ji-pin

    2016-03-01

    The technology of target recognition based on characteristic multi-spectrum has many advantages, such as strong detection capability and discriminating capability of target species. But there are some problems, it requires that you obtain the background spectrum as a priori knowledge, and it requires that the change of background spectrum is small with time. Thereby its application of real-time object recognition is limited in the new environment, or the complex environment. Based on magneto-optical modulation and characteristic multi-spectrum the method is designed, and the target is identified without prior access to the background spectrum. In order to achieve the function of the target information in the one acquisition time for tested, compared to conventional methods in terms of target detection, it's adaptability is better than before on the battlefield, and it is of more practical significance. Meanwhile, the magneto-optical modulator is used to suppress the interference of stray light background, thereby improving the probability of target recognition. Since the magneto-optical modulation provides incremental iterative target spectral information, therefore, even if the unknown background spectrum or background spectrum change is large, it can significantly improve the recognition accuracy of information through an iterative target spectrum. Different test targets back shimmering light intensity and background intensity values were analyzed during experiments, results showed that three targets for linearly polarized reflectance modulation is significantly stronger than the background. And it was of great influence to visible imaging target identification when measured target used camouflage color, but the system of polarization modulation type can still recognize target well. On this basis, the target range within 0.5 km x 2 km multi-wavelength characteristics of the target species were identified. When using three characteristic wavelengths, the

  2. Autonomous space target recognition and tracking approach using star sensors based on a Kalman filter.

    PubMed

    Ye, Tao; Zhou, Fuqiang

    2015-04-10

    When imaged by detectors, space targets (including satellites and debris) and background stars have similar point-spread functions, and both objects appear to change as detectors track targets. Therefore, traditional tracking methods cannot separate targets from stars and cannot directly recognize targets in 2D images. Consequently, we propose an autonomous space target recognition and tracking approach using a star sensor technique and a Kalman filter (KF). A two-step method for subpixel-scale detection of star objects (including stars and targets) is developed, and the combination of the star sensor technique and a KF is used to track targets. The experimental results show that the proposed method is adequate for autonomously recognizing and tracking space targets.

  3. In situ recognition of cell-surface glycans and targeted imaging of cancer cells

    PubMed Central

    Xu, Xiao-Ding; Cheng, Han; Chen, Wei-Hai; Cheng, Si-Xue; Zhuo, Ren-Xi; Zhang, Xian-Zheng

    2013-01-01

    Fluorescent sensors capable of recognizing cancer-associated glycans, such as sialyl Lewis X (sLex) tetrasaccharide, have great potential for cancer diagnosis and therapy. Studies on water-soluble and biocompatible sensors for in situ recognition of cancer-associated glycans in live cells and targeted imaging of cancer cells are very limited at present. Here we report boronic acid-functionalized peptide-based fluorescent sensors (BPFSs) for in situ recognition and differentiation of cancer-associated glycans, as well as targeted imaging of cancer cells. By screening BPFSs with different structures, it was demonstrated that BPFS1 with a FRGDF peptide could recognize cell-surface glycan of sLex with high specificity and thereafter fluorescently label and discriminate cancer cells through the cooperation with the specific recognition between RGD and integrins. The newly developed peptide-based sensor will find great potential as a fluorescent probe for cancer diagnosis. PMID:24042097

  4. Pattern recognition receptors as potential therapeutic targets in inflammatory rheumatic disease.

    PubMed

    Mullen, Lisa M; Chamberlain, Giselle; Sacre, Sandra

    2015-05-15

    The pattern recognition receptors of the innate immune system are part of the first line of defence against pathogens. However, they also have the ability to respond to danger signals that are frequently elevated during tissue damage and at sites of inflammation. Inadvertent activation of pattern recognition receptors has been proposed to contribute to the pathogenesis of many conditions including inflammatory rheumatic diseases. Prolonged inflammation most often results in pain and damage to tissues. In particular, the Toll-like receptors and nucleotide-binding oligomerisation domain-like receptors that form inflammasomes have been postulated as key contributors to the inflammation observed in rheumatoid arthritis, osteoarthritis, gout and systemic lupus erythematosus. As such, there is increasing interest in targeting these receptors for therapeutic treatment in the clinic. Here the role of pattern recognition receptors in the pathogenesis of these diseases is discussed, with an update on the development of interventions to modulate the activity of these potential therapeutic targets.

  5. Lys63-linked ubiquitin chain adopts multiple conformational states for specific target recognition.

    PubMed

    Liu, Zhu; Gong, Zhou; Jiang, Wen-Xue; Yang, Ju; Zhu, Wen-Kai; Guo, Da-Chuan; Zhang, Wei-Ping; Liu, Mai-Li; Tang, Chun

    2015-01-01

    A polyubiquitin comprises multiple covalently linked ubiquitins and recognizes myriad targets. Free or bound to ligands, polyubiquitins are found in different arrangements of ubiquitin subunits. To understand the structural basis for polyubiquitin quaternary plasticity and to explore the target recognition mechanism, we characterize the conformational space of Lys63-linked diubiquitin (K63-Ub2). Refining against inter-subunit paramagnetic NMR data, we show that free K63-Ub2 exists as a dynamic ensemble comprising multiple closed and open quaternary states. The quaternary dynamics enables K63-Ub2 to be specifically recognized in a variety of signaling pathways. When binding to a target protein, one of the preexisting quaternary states is selected and stabilized. A point mutation that shifts the equilibrium between the different states modulates the binding affinities towards K63-Ub2 ligands. This conformational selection mechanism at the quaternary level may be used by polyubiquitins of different lengths and linkages for target recognition. PMID:26090905

  6. An alternative mode of microRNA target recognition

    PubMed Central

    Chi, Sung Wook; Hannon, Gregory J.; Darnell, Robert B.

    2012-01-01

    MicroRNAs (miRNAs) regulate mRNA targets through perfect pairing with their seed region (position 2-7). Recently, a precise genome-wide map of miRNA interaction sites in mouse brain was generated by high-throughput sequencing of clusters of ~50 nucleotide RNA tags associated with Argonaute (Ago HITS-CLIP). By analyzing Ago HITS-CLIP “orphan clusters” – Ago binding regions from HITS-CLIP that cannot be explained by canonical seed matches – we have identified an alternative binding mode used by miRNAs. Specifically, G-bulge sites (position 5-6) are often bound and regulated by miR-124 in brain. More generally, bulged sites comprise ≥ 15% (≥ 1441 sites) of all Ago-miRNA interactions in mouse brain and are evolutionally conserved. We have termed position 6 the “pivot” nucleotide and suggest a model in which a transitional “nucleation-bulge” leads to functional bulge mRNA-miRNA interactions, expanding the number of potential miRNA regulatory sites. PMID:22343717

  7. Regulating the on-surface LNA probe density for the highest target recognition efficiency.

    PubMed

    Mishra, Sourav; Ghosh, Srabani; Mukhopadhyay, Rupa

    2014-09-01

    The recent emergence of on-surface LNA-based assays as potentially better alternatives over DNA-based approaches, due to enhanced sensitivity and target specificity, raises the need for the precise identification of the factors that control the performance of these assays. In this work, we investigated whether the probe density of fully modified ssLNA probes on the gold(111) surface could influence the target recognition capacity of the LNA sensing layer and illustrated simple means to control it, primarily by adjusting the salt concentration, nature of the cation, and pH of the immobilization buffer. It was observed that monovalent Na(+) could more effectively control the sensor probe density compared to bivalent Mg(2+), leading to better target recognition. Interestingly, unlike in the case of ssDNA sensor probes, the target recognition efficiency of the LNA layer at the optimum probe density was found to be almost spacer-independent, probably due to the rigidity of the LNA backbone. The optimized LNA sensor layer could discriminate single base mismatches, detect a minimum target DNA concentration of 5 nM, and sense a significant level of hybridization within a time scale of a few minutes. To our knowledge, for the first time, we identify the factors that control the on-surface LNA probe density for maximizing the performance of the LNA sensing layer.

  8. The research of multi-frame target recognition based on laser active imaging

    NASA Astrophysics Data System (ADS)

    Wang, Can-jin; Sun, Tao; Wang, Tin-feng; Chen, Juan

    2013-09-01

    Laser active imaging is fit to conditions such as no difference in temperature between target and background, pitch-black night, bad visibility. Also it can be used to detect a faint target in long range or small target in deep space, which has advantage of high definition and good contrast. In one word, it is immune to environment. However, due to the affect of long distance, limited laser energy and atmospheric backscatter, it is impossible to illuminate the whole scene at the same time. It means that the target in every single frame is unevenly or partly illuminated, which make the recognition more difficult. At the same time the speckle noise which is common in laser active imaging blurs the images . In this paper we do some research on laser active imaging and propose a new target recognition method based on multi-frame images . Firstly, multi pulses of laser is used to obtain sub-images for different parts of scene. A denoising method combined homomorphic filter with wavelet domain SURE is used to suppress speckle noise. And blind deconvolution is introduced to obtain low-noise and clear sub-images. Then these sub-images are registered and stitched to combine a completely and uniformly illuminated scene image. After that, a new target recognition method based on contour moments is proposed. Firstly, canny operator is used to obtain contours. For each contour, seven invariant Hu moments are calculated to generate the feature vectors. At last the feature vectors are input into double hidden layers BP neural network for classification . Experiments results indicate that the proposed algorithm could achieve a high recognition rate and satisfactory real-time performance for laser active imaging.

  9. Targeting the audience for AIDS messages by actual and perceived risk.

    PubMed

    Snyder, L B; Rouse, R A

    1992-01-01

    Since there are many ways to segment an audience into target groups, we suggest that a productive strategy for AIDS education is to divide the audience by their actual and perceived risk. We provide an example in which we segmented an urban U.S. sample and make suggestions as to how messages appropriate for each group can be constructed. In our sample, the "unthreatened" accurately assessed their low risk of AIDS, and showed high knowledge and tolerance rates. The "panicked," who included more women and Hispanics, inaccurately thought themselves at high risk because of misunderstandings about the causes of AIDS, and showed more intolerance of people with AIDS. "Deniers" continued to have multiple sexual partners and take precautions irregularly, despite seeing AIDS as a social problem and having more education and AIDS knowledge. In contrast, "gamblers" recognized their higher risk of AIDS and were most likely to have taken some action, although not enough to prevent sexual transmission of the HIV virus. PMID:1642959

  10. A biological cortex like target recognition and tracking in cluttered background

    NASA Astrophysics Data System (ADS)

    Tsitiridis, Aristeidis; Yuen, Peter; Hong, Kan; Chen, Tong; Kam, Firmin; Jackman, James; James, David; Richardson, Mark

    2009-09-01

    This paper reports how objects in street scenes, such as pedestrians and cars, can be spotted, recognised and then subsequently tracked in cluttered background using a cortex like vision approach. Unlike the conventional pixel based machine vision, tracking is achieved by recognition of the target implemented in neuromorphic ways. In this preliminary study the region of interest (ROI) of the image is spotted according to the salience and relevance of the scene and subsequently target recognition and tracking of the object in the ROI have been performed using a mixture of feed forward cortex like neuromorphic algorithms together with statistical classifier & tracker. Object recognitions for four categories (bike, people, car & background) using only one set of ventral visual like features have achieved a max of ~70% accuracy and the present system is quite effective for tracking prominent objects relatively independent of background types. The extension of the present achievement to improve the recognition accuracy as well as the identification of occluded objects from a crowd formulates the next stage of work.

  11. A fast recognition method of warhead target in boost phase using kinematic features

    NASA Astrophysics Data System (ADS)

    Chen, Jian; Xu, Shiyou; Tian, Biao; Wu, Jianhua; Chen, Zengping

    2015-12-01

    The radar targets number increases from one to more when the ballistic missile is in the process of separating the lower stage rocket or casting covers or other components. It is vital to identify the warhead target quickly among these multiple targets for radar tracking. A fast recognition method of the warhead target is proposed to solve this problem by using kinematic features, utilizing fuzzy comprehensive method and information fusion method. In order to weaken the influence of radar measurement noise, an extended Kalman filter with constant jerk model (CJEKF) is applied to obtain more accurate target's motion information. The simulation shows the validity of the algorithm and the effects of the radar measurement precision upon the algorithm's performance.

  12. MicroRNA Target Recognition: Insights from Transcriptome-Wide Non-Canonical Interactions

    PubMed Central

    Seok, Heeyoung; Ham, Juyoung; Jang, Eun-Sook; Chi, Sung Wook

    2016-01-01

    MicroRNAs (miRNAs) are small non-coding RNAs (∼22 nucleotides) regulating gene expression at the post-transcriptional level. By directing the RNA-induced silencing complex (RISC) to bind specific target mRNAs, miRNA can repress target genes and affect various biological phenotypes. Functional miRNA target recognition is known to majorly attribute specificity to consecutive pairing with seed region (position 2–8) of miRNA. Recent advances in a transcriptome-wide method of mapping miRNA binding sites (Ago HITS-CLIP) elucidated that a large portion of miRNA-target interactions in vivo are mediated not only through the canonical “seed sites” but also via non-canonical sites (∼15–80%), setting the stage to expand and determine their properties. Here we focus on recent findings from transcriptome-wide non-canonical miRNA-target interactions, specifically regarding “nucleation bulges” and “seed-like motifs”. We also discuss insights from Ago HITS-CLIP data alongside structural and biochemical studies, which highlight putative mechanisms of miRNA target recognition, and the biological significance of these non-canonical sites mediating marginal repression. PMID:27117456

  13. High-resolution crystal structure reveals molecular details of target recognition by bacitracin

    PubMed Central

    Economou, Nicoleta J.; Cocklin, Simon; Loll, Patrick J.

    2013-01-01

    Bacitracin is a metalloantibiotic agent that is widely used as a medicine and feed additive. It interferes with bacterial cell-wall biosynthesis by binding undecaprenyl-pyrophosphate, a lipid carrier that serves as a critical intermediate in cell wall production. Despite bacitracin’s broad use, the molecular details of its target recognition have not been elucidated. Here we report a crystal structure for the ternary complex of bacitracin A, zinc, and a geranyl-pyrophosphate ligand at a resolution of 1.1 Å. The antibiotic forms a compact structure that completely envelopes the ligand’s pyrophosphate group, together with flanking zinc and sodium ions. The complex adopts a highly amphipathic conformation that offers clues to antibiotic function in the context of bacterial membranes. Bacitracin’s efficient sequestration of its target represents a previously unseen mode for the recognition of lipid pyrophosphates, and suggests new directions for the design of next-generation antimicrobial agents. PMID:23940351

  14. Enhanced target recognition of nanoparticles by cocktail PEGylation with chains of varying lengths.

    PubMed

    Ishii, Takehiko; Miyata, Kanjiro; Anraku, Yasutaka; Naito, Mitsuru; Yi, Yu; Jinbo, Takao; Takae, Seiji; Fukusato, Yu; Hori, Mao; Osada, Kensuke; Kataoka, Kazunori

    2016-01-25

    Monodispersed gold nanoparticles (AuNPs) were simultaneously decorated with lactosylated and non-modified shorter poly(ethylene glycol)s (PEGs) to enhance their target recognition. The decoration with sufficiently shorter PEGs dramatically enhanced the multivalent binding ability of lactosylated AuNPs to the lectin-fixed surface, possibly due to the enhanced mobility of the ligands via the spacer effect generated by the shorter PEG chains. PMID:26658952

  15. Classification on the monogenic scale space: application to target recognition in SAR image.

    PubMed

    Ganggang Dong; Gangyao Kuang

    2015-08-01

    This paper introduces a novel classification strategy based on the monogenic scale space for target recognition in Synthetic Aperture Radar (SAR) image. The proposed method exploits monogenic signal theory, a multidimensional generalization of the analytic signal, to capture the characteristics of SAR image, e.g., broad spectral information and simultaneous spatial localization. The components derived from the monogenic signal at different scales are then applied into a recently developed framework, sparse representation-based classification (SRC). Moreover, to deal with the data set, whose target classes are not linearly separable, the classification via kernel combination is proposed, where the multiple components of the monogenic signal are jointly considered into a unifying framework for target recognition. The novelty of this paper comes from: the development of monogenic feature via uniformly downsampling, normalization, and concatenation of the components at various scales; the development of score-level fusion for SRCs; and the development of composite kernel learning for classification. In particular, the comparative experimental studies under nonliteral operating conditions, e.g., structural modifications, random noise corruption, and variations in depression angle, are performed. The comparative experimental studies of various algorithms, including the linear support vector machine and the kernel version, the SRC and the variants, kernel SRC, kernel linear representation, and sparse representation of monogenic signal, are performed too. The feasibility of the proposed method has been successfully verified using Moving and Stationary Target Acquiration and Recognition database. The experimental results demonstrate that significant improvement for recognition accuracy can be achieved by the proposed method in comparison with the baseline algorithms.

  16. An algorithm for automatic target recognition using passive radar and an EKF for estimating aircraft orientation

    NASA Astrophysics Data System (ADS)

    Ehrman, Lisa M.

    2005-07-01

    Rather than emitting pulses, passive radar systems rely on "illuminators of opportunity," such as TV and FM radio, to illuminate potential targets. These systems are attractive since they allow receivers to operate without emitting energy, rendering them covert. Until recently, most of the research regarding passive radar has focused on detecting and tracking targets. This dissertation focuses on extending the capabilities of passive radar systems to include automatic target recognition. The target recognition algorithm described in this dissertation uses the radar cross section (RCS) of potential targets, collected over a short period of time, as the key information for target recognition. To make the simulated RCS as accurate as possible, the received signal model accounts for aircraft position and orientation, propagation losses, and antenna gain patterns. An extended Kalman filter (EKF) estimates the target's orientation (and uncertainty in the estimate) from velocity measurements obtained from the passive radar tracker. Coupling the aircraft orientation and state with the known antenna locations permits computation of the incident and observed azimuth and elevation angles. The Fast Illinois Solver Code (FISC) simulates the RCS of potential target classes as a function of these angles. Thus, the approximated incident and observed angles allow the appropriate RCS to be extracted from a database of FISC results. Using this process, the RCS of each aircraft in the target class is simulated as though each is executing the same maneuver as the target detected by the system. Two additional scaling processes are required to transform the RCS into a power profile (magnitude only) simulating the signal in the receiver. First, the RCS is scaled by the Advanced Refractive Effects Prediction System (AREPS) code to account for propagation losses that occur as functions of altitude and range. Then, the Numerical Electromagnetic Code (NEC2) computes the antenna gain pattern

  17. Model-based automatic target recognition using hierarchical foveal machine vision

    NASA Astrophysics Data System (ADS)

    McKee, Douglas C.; Bandera, Cesar; Ghosal, Sugata; Rauss, Patrick J.

    1996-06-01

    This paper presents a target detection and interrogation techniques for a foveal automatic target recognition (ATR) system based on the hierarchical scale-space processing of imagery from a rectilinear tessellated multiacuity retinotopology. Conventional machine vision captures imagery and applies early vision techniques with uniform resolution throughout the field-of-view (FOV). In contrast, foveal active vision features graded acuity imagers and processing coupled with context sensitive gaze control, analogous to that prevalent throughout vertebrate vision. Foveal vision can operate more efficiently in dynamic scenarios with localized relevance than uniform acuity vision because resolution is treated as a dynamically allocable resource. Foveal ATR exploits the difference between detection and recognition resolution requirements and sacrifices peripheral acuity to achieve a wider FOV (e.g. faster search), greater localized resolution where needed (e.g., more confident recognition at the fovea), and faster frame rates (e.g., more reliable tracking and navigation) without increasing processing requirements. The rectilinearity of the retinotopology supports a data structure that is a subset of the image pyramid. This structure lends itself to multiresolution and conventional 2-D algorithms, and features a shift invariance of perceived target shape that tolerates sensor pointing errors and supports multiresolution model-based techniques. The detection technique described in this paper searches for regions-of- interest (ROIs) using the foveal sensor's wide FOV peripheral vision. ROIs are initially detected using anisotropic diffusion filtering and expansion template matching to a multiscale Zernike polynomial-based target model. Each ROI is then interrogated to filter out false target ROIs by sequentially pointing a higher acuity region of the sensor at each ROI centroid and conducting a fractal dimension test that distinguishes targets from structured clutter.

  18. Structural basis for the recognition of guide RNA and target DNA heteroduplex by Argonaute

    PubMed Central

    Miyoshi, Tomohiro; Ito, Kosuke; Murakami, Ryo; Uchiumi, Toshio

    2016-01-01

    Argonaute proteins are key players in the gene silencing mechanisms mediated by small nucleic acids in all domains of life from bacteria to eukaryotes. However, little is known about the Argonaute protein that recognizes guide RNA/target DNA. Here, we determine the 2 Å crystal structure of Rhodobacter sphaeroides Argonaute (RsAgo) in a complex with 18-nucleotide guide RNA and its complementary target DNA. The heteroduplex maintains Watson–Crick base-pairing even in the 3′-region of the guide RNA between the N-terminal and PIWI domains, suggesting a recognition mode by RsAgo for stable interaction with the target strand. In addition, the MID/PIWI interface of RsAgo has a system that specifically recognizes the 5′ base-U of the guide RNA, and the duplex-recognition loop of the PAZ domain is important for the DNA silencing activity. Furthermore, we show that Argonaute discriminates the nucleic acid type (RNA/DNA) by recognition of the duplex structure of the seed region. PMID:27325485

  19. ARTMAP neural networks for information fusion and data mining: map production and target recognition methodologies.

    PubMed

    Parsons, Olga; Carpenter, Gail A

    2003-09-01

    The Sensor Exploitation Group of MIT Lincoln Laboratory incorporated an early version of the ARTMAP neural network as the recognition engine of a hierarchical system for fusion and data mining of registered geospatial images. The Lincoln Lab system has been successfully fielded, but is limited to target/non-target identifications and does not produce whole maps. Procedures defined here extend these capabilities by means of a mapping method that learns to identify and distribute arbitrarily many target classes. This new spatial data mining system is designed particularly to cope with the highly skewed class distributions of typical mapping problems. Specification of canonical algorithms and a benchmark testbed has enabled the evaluation of candidate recognition networks as well as pre- and post-processing and feature selection options. The resulting mapping methodology sets a standard for a variety of spatial data mining tasks. In particular, training pixels are drawn from a region that is spatially distinct from the mapped region, which could feature an output class mix that is substantially different from that of the training set. The system recognition component, default ARTMAP, with its fully specified set of canonical parameter values, has become the a priori system of choice among this family of neural networks for a wide variety of applications.

  20. [High-speed target recognition positioning system based on multi-spectral radiation characteristics].

    PubMed

    Li, Jian-Min; Wang, Gao

    2014-11-01

    In order to achieve quick recognition and positioning of the high-speed target, using multi-spectral radiation combined with acoustic positioning technology, in the passive state, the blast wave spectral characteristics and acoustic characteristics of the measured target were rapidly obtained, thus analysis was performed to determine the type, location and other important parameters. Multi-spectral radiation detection target recognition formula was deduced. The accuracy of the optical path length and the logical integration time was calculated by shock acoustic positioning method. Experiments used 5.56 mm NATO bullets, 7.62 mm 56-rifle bullets, 12.7 mm 54 type machine-gun bullets as a target identified projectile. Interference fringes were collected by the static Fourier transform interferometer system and ICX387AL type CCD, and the peak of sound pressure was collected using 2209 pulse sound pressure meter made by B & K Company from Denmark Experimental results show that for the 5.56 mm NATO bullets, the three characteristic wavelengths position amplitudes are close to each other, with the maximum amplitude at 966 nm; For the 7.62 mm 56-rifle bullets, 935 nm is the maximum amplitude position, while for 966 and 997 nm position the magnitudes are sunukar; For 12.7 mm 54 type machine-gun bullets, the three wavelengths show a ladder-like distribution. With the increase in the detection distance spectral radiation energy decreased. Meanwhile, with the decrease in the total radiation spectrum, the spectrum of target was affected strongly by background noise, and the SNR of system was decreased. But the spectral characteristics of different target still exist, the target species can be identified by the system with the ratio algorithm of characteristic peaks. Through spectral calibration and characteristic wavelengths extraction, the target can successfully identify the type of projectile and target position, and it meets the design requirements. PMID:25752076

  1. Research on target recognition techniques of radar networking based on fuzzy mathematics

    NASA Astrophysics Data System (ADS)

    Guan, Chengbin; Wang, Guohong; Guan, Chengzhun; Pan, Jinshan

    2007-11-01

    Nowadays there are more and more targets, so it is more difficult for radar networking to track the important targets. To reduce the pressure on radar networking and the waste of ammunition, it is very necessary for radar networking to recognize the targets. Two target recognition approaches of radar networking based on fuzzy mathematics are proposed in this paper, which are multi-level fuzzy synthetical evaluation technique and lattice approaching degree technique. By analyzing the principles, the application techniques are given, the merits and shortcomings are also analyzed, and applying environments are advised. Another emphasis is the compare between the multiple mono-level fuzzy synthetical evaluation and the multi-level fuzzy synthetical evaluation, an instance is carried out to illuminate the problem, then the results are analyzed in theory, the conclusions are gotten which can be instructions for application in engineering.

  2. Facial Expression Recognition: Can Preschoolers with Cochlear Implants and Hearing Aids Catch It?

    ERIC Educational Resources Information Center

    Wang, Yifang; Su, Yanjie; Fang, Ping; Zhou, Qingxia

    2011-01-01

    Tager-Flusberg and Sullivan (2000) presented a cognitive model of theory of mind (ToM), in which they thought ToM included two components--a social-perceptual component and a social-cognitive component. Facial expression recognition (FER) is an ability tapping the social-perceptual component. Previous findings suggested that normal hearing…

  3. Synthesis of Common Arabic Handwritings to Aid Optical Character Recognition Research.

    PubMed

    Dinges, Laslo; Al-Hamadi, Ayoub; Elzobi, Moftah; El-Etriby, Sherif

    2016-01-01

    Document analysis tasks such as pattern recognition, word spotting or segmentation, require comprehensive databases for training and validation. Not only variations in writing style but also the used list of words is of importance in the case that training samples should reflect the input of a specific area of application. However, generation of training samples is expensive in the sense of manpower and time, particularly if complete text pages including complex ground truth are required. This is why there is a lack of such databases, especially for Arabic, the second most popular language. However, Arabic handwriting recognition involves different preprocessing, segmentation and recognition methods. Each requires particular ground truth or samples to enable optimal training and validation, which are often not covered by the currently available databases. To overcome this issue, we propose a system that synthesizes Arabic handwritten words and text pages and generates corresponding detailed ground truth. We use these syntheses to validate a new, segmentation based system that recognizes handwritten Arabic words. We found that a modification of an Active Shape Model based character classifiers-that we proposed earlier-improves the word recognition accuracy. Further improvements are achieved, by using a vocabulary of the 50,000 most common Arabic words for error correction. PMID:26978368

  4. Synthesis of Common Arabic Handwritings to Aid Optical Character Recognition Research

    PubMed Central

    Dinges, Laslo; Al-Hamadi, Ayoub; Elzobi, Moftah; El-etriby, Sherif

    2016-01-01

    Document analysis tasks such as pattern recognition, word spotting or segmentation, require comprehensive databases for training and validation. Not only variations in writing style but also the used list of words is of importance in the case that training samples should reflect the input of a specific area of application. However, generation of training samples is expensive in the sense of manpower and time, particularly if complete text pages including complex ground truth are required. This is why there is a lack of such databases, especially for Arabic, the second most popular language. However, Arabic handwriting recognition involves different preprocessing, segmentation and recognition methods. Each requires particular ground truth or samples to enable optimal training and validation, which are often not covered by the currently available databases. To overcome this issue, we propose a system that synthesizes Arabic handwritten words and text pages and generates corresponding detailed ground truth. We use these syntheses to validate a new, segmentation based system that recognizes handwritten Arabic words. We found that a modification of an Active Shape Model based character classifiers—that we proposed earlier—improves the word recognition accuracy. Further improvements are achieved, by using a vocabulary of the 50,000 most common Arabic words for error correction. PMID:26978368

  5. Pose recognition of articulated target based on ladar range image with elastic shape analysis

    NASA Astrophysics Data System (ADS)

    Liu, Zheng-Jun; Li, Qi; Wang, Qi

    2014-10-01

    Elastic shape analysis is introduced for pose recognition of articulated target which is based on small samples of ladar range images. Shape deformations caused by poses changes represented as closed elastic curves given by the square-root velocity function geodesics are used to quantify shape differences and the Karcher mean is used to build a model library. Three kinds of moments - Hu moment invariants, affine moment invariants, and Zernike moment invariants based on support vector machines (SVMs) - are applied to evaluate this approach. The experiment results show that no matter what the azimuth angles of the testing samples are, this approach is capable of achieving a high recognition rate using only 3 model samples with different carrier to noise ratios (CNR); the performance of this approach is much better than that of three kinds of moments based on SVM, especially under high noise conditions.

  6. A new technique of recognition for coded targets in optical 3D measurement

    NASA Astrophysics Data System (ADS)

    Guo, Changye; Cheng, Xiaosheng; Cui, Haihua; Dai, Ning; Weng, Jinping

    2014-11-01

    A new technique for coded targets recognition in optical 3D-measurement application is proposed in this paper. Traditionally, point cloud registration is based on homologous features, such as the curvature, which is time-consuming and not reliable. For this, we paste some coded targets onto the surface of the object to be measured to improve the optimum target location and accurate correspondence among multi-source images. Circular coded targets are used, and an algorithm to automatically detecting them is proposed. This algorithm extracts targets with intensive bimodal histogram features from complex background, and filters noise according to their size, shape and intensity. In addition, the coded targets' identification is conducted out by their ring codes. We affine them around the circle inversely, set foreground and background respectively as 1 and 0 to constitute a binary number, and finally shift one bit every time to calculate a decimal one of the binary number to determine a minimum decimal number as its code. In this 3Dmeasurement application, we build a mutual relationship between different viewpoints containing three or more coded targets with different codes. Experiments show that it is of efficiency to obtain global surface data of an object to be measured and is robust to the projection angles and noise.

  7. Water-mediated recognition of t1-adenosine anchors Argonaute2 to microRNA targets

    PubMed Central

    Schirle, Nicole T; Sheu-Gruttadauria, Jessica; Chandradoss, Stanley D; Joo, Chirlmin; MacRae, Ian J

    2015-01-01

    MicroRNAs (miRNAs) direct post-transcriptional regulation of human genes by guiding Argonaute proteins to complementary sites in messenger RNAs (mRNAs) targeted for repression. An enigmatic feature of many conserved mammalian miRNA target sites is that an adenosine (A) nucleotide opposite miRNA nucleotide-1 confers enhanced target repression independently of base pairing potential to the miRNA. In this study, we show that human Argonaute2 (Ago2) possesses a solvated surface pocket that specifically binds adenine nucleobases in the 1 position (t1) of target RNAs. t1A nucleotides are recognized indirectly through a hydrogen-bonding network of water molecules that preferentially interacts with the N6 amine on adenine. t1A nucleotides are not utilized during the initial binding of Ago2 to its target, but instead function by increasing the dwell time on target RNA. We also show that N6 adenosine methylation blocks t1A recognition, revealing a possible mechanism for modulation of miRNA target site potency. DOI: http://dx.doi.org/10.7554/eLife.07646.001 PMID:26359634

  8. The research of edge extraction and target recognition based on inherent feature of objects

    NASA Astrophysics Data System (ADS)

    Xie, Yu-chan; Lin, Yu-chi; Huang, Yin-guo

    2008-03-01

    Current research on computer vision often needs specific techniques for particular problems. Little use has been made of high-level aspects of computer vision, such as three-dimensional (3D) object recognition, that are appropriate for large classes of problems and situations. In particular, high-level vision often focuses mainly on the extraction of symbolic descriptions, and pays little attention to the speed of processing. In order to extract and recognize target intelligently and rapidly, in this paper we developed a new 3D target recognition method based on inherent feature of objects in which cuboid was taken as model. On the basis of analysis cuboid nature contour and greyhound distributing characteristics, overall fuzzy evaluating technique was utilized to recognize and segment the target. Then Hough transform was used to extract and match model's main edges, we reconstruct aim edges by stereo technology in the end. There are three major contributions in this paper. Firstly, the corresponding relations between the parameters of cuboid model's straight edges lines in an image field and in the transform field were summed up. By those, the aimless computations and searches in Hough transform processing can be reduced greatly and the efficiency is improved. Secondly, as the priori knowledge about cuboids contour's geometry character known already, the intersections of the component extracted edges are taken, and assess the geometry of candidate edges matches based on the intersections, rather than the extracted edges. Therefore the outlines are enhanced and the noise is depressed. Finally, a 3-D target recognition method is proposed. Compared with other recognition methods, this new method has a quick response time and can be achieved with high-level computer vision. The method present here can be used widely in vision-guide techniques to strengthen its intelligence and generalization, which can also play an important role in object tracking, port AGV, robots

  9. Acute adrenal insufficiency: an aide-memoire of the critical importance of its recognition and prevention.

    PubMed

    Gargya, A; Chua, E; Hetherington, J; Sommer, K; Cooper, M

    2016-03-01

    Adrenal crisis is a life-threatening emergency that causes significant excess mortality in patients with adrenal insufficiency. Delayed recognition by medical staff of an impending adrenal crisis and failure to give timely hydrocortisone therapy within the emergency department continue to be commonly encountered, even in metropolitan teaching hospitals. Within the authors' institutions, several cases of poorly handled adrenal crises have occurred over the last 2 years. Anecdotal accounts from members of the Addison's support group suggest that these issues are common in Australia. This manuscript is a timely reminder for clinical staff on the critical importance of the recognition, treatment and prevention of adrenal crisis. The manuscript: (i) outlines a case and the clinical outcome of sub-optimally managed adrenal crisis, (ii) summarises the clinical features and acute management of adrenal crisis, (iii) provides recommendations on the prevention of adrenal crisis and (iv) provides guidance on the management of 'sick days' in patients with adrenal insufficiency.

  10. Do orthographic cues aid language recognition? A laterality study with French-English bilinguals.

    PubMed

    Vaid, Jyotsna; Frenck-Mestre, Cheryl

    2002-07-01

    Sixteen French-English late bilinguals performed a speeded language recognition task on lateralized words that were either marked or unmarked for language on the basis of digram frequency. Response latencies were faster to orthographically marked than unmarked words, particularly in the second language (English). Furthermore, L2 marked words were responded to faster than L1 marked words. These effects were especially prominent for words presented in the left visual field. It is suggested that subjects made use of different strategies in performing the task of language recognition task, with a perceptual search strategy deployed to identify orthographically marked words, resulting in an L2 advantage for such words, and a lexical search strategy deployed for unmarked words, resulting in an L1 advantage for such words.

  11. Two-step, PCR-free telomerase detection by using exonuclease III-aided target recycling.

    PubMed

    Zuo, Xiaolei; Xia, Fan; Patterson, Adriana; Soh, H Tom; Xiao, Yi; Plaxco, Kevin W

    2011-12-16

    We report the sensitive detection of telomerase activity by using exonuclease III-aided target recycling to amplify the signal produced by a chimeric LNA-DNA molecular beacon. We demonstrate the specific detection of as few as 30 telomerase-positive breast cancer cells in a single-measurement fluorescence assay that avoids the problematic PCR and gel analysis of the current "gold-standard" assay.

  12. Design and recognition of three dimensional calibration target based on coded marker

    NASA Astrophysics Data System (ADS)

    Zhai, You; Xiong, Wei; Zeng, Luan; Gu, Dalong

    2015-08-01

    Traditional three-dimensional (3D) calibration targets consist of two or three mutual orthogonal planes (each of the planes contains several control points constituted by corners or circular points) that cannot be captured simultaneously by cameras in front view. Therefore, large perspective distortions exist in the images of the calibration targets resulting in inaccurate image coordinate detection of the control points. Besides, in order to eliminate mismatches, recognition of the control points usually needs manual intervention consuming large amount of time. A new design of 3D calibration target is presented for automatic and accurate camera calibration. The target employs two parallel planes instead of orthogonal planes to reduce perspective distortion, which can be captured simultaneously by cameras in front view. Control points of the target are constituted by carefully designed circular coded markers, which can be used to realize automatic recognition without manual intervention. Due to perspective projection, projections of the circular coded markers' centers deviate from the centers of their corresponding imaging ellipses. Colinearity of the control points is used to correct perspective distortions of the imaging ellipses. Experiment results show that the calibration target can be automatically and correctly recognized under large illumination and viewpoint change. The image extraction errors of the control points are under 0.1 pixels. When applied to binocular cameras calibration, the mean reprojection errors are less than 0.15 pixels and the 3D measurement errors are less than 0.2mm in x and y axis and 0.5mm in z axis respectively.

  13. Three-dimensional transformation for automatic target recognition using lidar data

    NASA Astrophysics Data System (ADS)

    Nieves, Ruben D.; Reynolds, William D., Jr.

    2010-04-01

    The three-dimensional (3-D) nature and the unorganized structure of topographic LIDAR data pose several challenges for target recognition tasks. In the past, several approaches have applied two-dimensional transformations such as spinimages or Digital Elevation Maps (DEMs) as an intermediate step for analyzing the 3-D data with two-dimensional (2-D) methods. However, these techniques are computationally intensive and often sacrifice some of the overall geometrical relationship of the target points. In this paper, we present a simple and efficient 3-D spatial transformation that preserves the geometrical attributes of the LIDAR data in all its dimensions. This transformation permits the utilization of well established statistical and shapebased descriptors for the implementation of an automatic target recognition algorithm. We evaluate our transformation and analysis technique on a set of simulated LIDAR point clouds of ground vehicles with varied obstructions and noise levels. Classification results demonstrate that our approach is efficient, tolerant to scale, rotation, and robust to noise and other degradations.

  14. Role for the propofol hydroxyl in anesthetic protein target molecular recognition.

    PubMed

    Woll, Kellie A; Weiser, Brian P; Liang, Qiansheng; Meng, Tao; McKinstry-Wu, Andrew; Pinch, Benika; Dailey, William P; Gao, Wei Dong; Covarrubias, Manuel; Eckenhoff, Roderic G

    2015-06-17

    Propofol is a widely used intravenous general anesthetic. We synthesized 2-fluoro-1,3-diisopropylbenzene, a compound that we call "fropofol", to directly assess the significance of the propofol 1-hydroxyl for pharmacologically relevant molecular recognition in vitro and for anesthetic efficacy in vivo. Compared to propofol, fropofol had a similar molecular volume and only a small increase in hydrophobicity. Isothermal titration calorimetry and competition assays revealed that fropofol had higher affinity for a protein site governed largely by van der Waals interactions. Within another protein model containing hydrogen bond interactions, propofol demonstrated higher affinity. In vivo, fropofol demonstrated no anesthetic efficacy, but at high concentrations produced excitatory activity in tadpoles and mice; fropofol also antagonized propofol-induced hypnosis. In a propofol protein target that contributes to hypnosis, α1β2γ2L GABAA receptors, fropofol demonstrated no significant effect alone or on propofol positive allosteric modulation of the ion channel, suggesting an additional requirement for the 1-hydroxyl within synaptic GABAA receptor site(s). However, fropofol caused similar adverse cardiovascular effects as propofol by a dose-dependent depression of myocardial contractility. Our results directly implicate the propofol 1-hydroxyl as contributing to molecular recognition within protein targets leading to hypnosis, but not necessarily within protein targets leading to side effects of the drug.

  15. Infrared zoom lens design based on target correlation recognition and tracking

    NASA Astrophysics Data System (ADS)

    Zhang, Su; Duan, Jin; Fu, Qiang; Wang, Wen-sheng

    2015-10-01

    To expand the infrared (IR) target detection scope of tank, according to the requirements of real-time recognition and tracking for target with joint transform correlator (JTC) a set of infrared (IR) continuous zoom optical system with 8-12 μm long-wave-band was designed, which applied long-wave 384× 288 element uncooled thermal IR focal plane array detector. In this system, the zoom ratio is 8× , the range of the focal length is 30mm-240mm, F number is 2 and during the zoom process the relative aperture is invariant. This system used the mechanical compensation method, after designed and optimized, it can be composed of 6 spherical lenses with Ge and ZnS only. The design results show that when the cutoff frequency is 14lp/mm, in the whole range of the focal length the MTF curves are all above 0.52 which all approach to the diffraction limit curves. And the spot size is smaller than the pixel size of the receiver. It can meet the requirement of long IR target recognition and tracking in the practical application.

  16. Nonlinear techniques in optical synthetic aperture radar image generation and target recognition.

    PubMed

    Weaver, S; Wagner, K

    1995-07-10

    One of the most successful optical signal-processing applications to date has been the use of optical processors to convert synthetic aperture radar (SAR) data into images of the radar reflectivity of the ground. We have demonstrated real-time input to a high-space-bandwidth optical SAR imagegeneration system by using a dynamic organic holographic recording medium and SAR phase-history data. Real-time speckle reduction in optically processed SAR imagery has been accomplished by the use of multilook averaging to achieve nonlinear modulus-squared accumulation of subaperture images. We designed and assembled an all-optical system that accomplished real-time target recognition in SAR imagery. This system employed a simple square-law nonlinearity in the form of an optically addressed spatial light modulator at the SAR image plane to remove the effects of speckle phase profiles returned from complex SAR targets. The detection stage enabled the creation of an optical SAR automatic target recognition system as a nonlinear cascade of an optical SAR image generator and an optical correlator.

  17. Vigilante: Ultrafast Smart Sensor for Target Recognition and Precision Tracking in a Simulated CMD Scenario

    NASA Technical Reports Server (NTRS)

    Uldomkesmalee, Suraphol; Suddarth, Steven C.

    1997-01-01

    VIGILANTE is an ultrafast smart sensor testbed for generic Automatic Target Recognition (ATR) applications with a series of capability demonstration focussed on cruise missile defense (CMD). VIGILANTE's sensor/processor architecture is based on next-generation UV/visible/IR sensors and a tera-operations per second sugar-cube processor, as well as supporting airborne vehicle. Excellent results of efficient ATR methodologies that use an eigenvectors/neural network combination and feature-based precision tracking have been demonstrated in the laboratory environment.

  18. Optical implementation of a feature-based neural network with application to automatic target recognition

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin; Stoner, William W.

    1993-01-01

    An optical neural network based on the neocognitron paradigm is introduced. A novel aspect of the architecture design is shift-invariant multichannel Fourier optical correlation within each processing layer. Multilayer processing is achieved by feeding back the ouput of the feature correlator interatively to the input spatial light modulator and by updating the Fourier filters. By training the neural net with characteristic features extracted from the target images, successful pattern recognition with intraclass fault tolerance and interclass discrimination is achieved. A detailed system description is provided. Experimental demonstrations of a two-layer neural network for space-object discrimination is also presented.

  19. Automatic target recognition using a feature-based optical neural network

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin

    1992-01-01

    An optical neural network based upon the Neocognitron paradigm (K. Fukushima et al. 1983) is introduced. A novel aspect of the architectural design is shift-invariant multichannel Fourier optical correlation within each processing layer. Multilayer processing is achieved by iteratively feeding back the output of the feature correlator to the input spatial light modulator and updating the Fourier filters. By training the neural net with characteristic features extracted from the target images, successful pattern recognition with intra-class fault tolerance and inter-class discrimination is achieved. A detailed system description is provided. Experimental demonstration of a two-layer neural network for space objects discrimination is also presented.

  20. Pattern recognition of the targets with help of polarization properties of the signal

    NASA Astrophysics Data System (ADS)

    Ponomaryov, Volodymyr I.; de Rivera, Luis N.; Castellanos, Aldo B.; Popov, Anatoly V.

    1999-10-01

    We proposed to use the possibility of recognition of the targets on background of the scattering from the surface, weather objects with the help of polarimetric 3-cm radar. It has been investigated such polarization characteristics: the amplitudes of the polarization matrix elements; an anisotropy coefficient; depolarization coefficient; asymmetry coefficient; the energy section was less than 1 dB at ranges up to 15 km and less than 1.5 dB at ranges up to 100 km. During the experiments urban objects and 6 various ships of small displacement having the closest values of the backscattering cross-section were used. The analysis has shown: the factor of the polarization selection for anisotropy objects and weather objects had the values about 0.02-0.08 Isotropy had the values of polarimetric correlation factor for hydrometers about 0.7-0.8, for earth surface about 0.8-0.9, for sea surface - from 0.33 to 0.7. The results of the work of recognition algorithm of a class 'concrete objects', and 'metal objects' are submitted as example in the paper. The result of experiments have shown that the probability of correct recognition of the identified objects was in the limits from 0.93 to 0.97.

  1. Advances in image compression and automatic target recognition; Proceedings of the Meeting, Orlando, FL, Mar. 30, 31, 1989

    NASA Technical Reports Server (NTRS)

    Tescher, Andrew G. (Editor)

    1989-01-01

    Various papers on image compression and automatic target recognition are presented. Individual topics addressed include: target cluster detection in cluttered SAR imagery, model-based target recognition using laser radar imagery, Smart Sensor front-end processor for feature extraction of images, object attitude estimation and tracking from a single video sensor, symmetry detection in human vision, analysis of high resolution aerial images for object detection, obscured object recognition for an ATR application, neural networks for adaptive shape tracking, statistical mechanics and pattern recognition, detection of cylinders in aerial range images, moving object tracking using local windows, new transform method for image data compression, quad-tree product vector quantization of images, predictive trellis encoding of imagery, reduced generalized chain code for contour description, compact architecture for a real-time vision system, use of human visibility functions in segmentation coding, color texture analysis and synthesis using Gibbs random fields.

  2. Versatile TPR domains accommodate different modes of target protein recognition and function.

    PubMed

    Allan, Rudi Kenneth; Ratajczak, Thomas

    2011-07-01

    The tetratricopeptide repeat (TPR) motif is one of many repeat motifs that form structural domains in proteins that can act as interaction scaffolds in the formation of multi-protein complexes involved in numerous cellular processes such as transcription, the cell cycle, protein translocation, protein degradation and host defence against invading pathogens. The crystal structures of many TPR domain-containing proteins have been determined, showing TPR motifs as two anti-parallel α-helices packed in tandem arrays to form a structure with an amphipathic groove which can bind a target peptide. This is however not the only mode of target recognition by TPR domains, with short amino acid insertions and alternative TPR motif conformations also shown to contribute to protein interactions, highlighting diversity in TPR domains and the versatility of this structure in mediating biological events.

  3. Automatic target recognition and tracking using an acousto-optic image correlator

    SciTech Connect

    Molley, P.A.; Kast, B.A. )

    1992-05-01

    This paper discusses a hybrid electro-optic image processor, developed for automatic target recognition and tracking using an acousto-optic correlator and digital electronics. The optical system performs the computationally intensive correlation operation on the large 2-D input scenes. The electronics provide the decision-making capability and also perform part of the postprocessing needed for increasing the peak-to-clutter ratio in cluttered scenes. The system is able to analyze each correlation plane and apply a real-time template selection algorithm to accommodate scale or rotation changes of the target. A demonstration of the current system capabilities is presented using a terrain board with several different types of stationary and moving model vehicles.

  4. Automatic target recognition using both measurements from identity sensors and motion information from tracking sensors

    NASA Astrophysics Data System (ADS)

    Copsey, Keith D.

    2005-05-01

    The majority of automatic target recognition (ATR) studies are formulated as a traditional classification problem. Specifically, using a training set of target exemplars, a classifier is developed for application to isolated measurements of targets. Performance is assessed using a test set of target exemplars. Unfortunately, this is a simplification of the ATR problem. Often, the operating conditions differ from those prevailing at the time of training data collection, which can have severe effects on the obtained performance. It is therefore becoming increasingly recognised that development of robust ATR systems requires more than just consideration of the traditional classification problem. In particular, one should make use of any extra information or data that is available. The example in this paper focuses on a hybrid ATR system being designed to utilise both measurements from identity sensors (such as radar profiles) and motion information from tracking sensors to classify targets. The first-stage of the system uses mixture-model classifiers to classify targets into generic classes based upon data from (long range) tracking sensors. Where the generic classes are related to platform types (e.g. fast-jets, heavy bombers and commercial aircraft), the initial classifications can be used to assist the military commander's early decision making. The second-stage of the system uses measurements from (closer-range) identity sensors to classify the targets into individual target types, while taking into account the (uncertain) outputs from the first-stage. A Bayesian classifier is proposed for the second-stage, so that the first-stage outputs can be incorporated into the second-stage prior class probabilities.

  5. The TCF C-clamp DNA binding domain expands the Wnt transcriptome via alternative target recognition

    PubMed Central

    Hoverter, Nate P.; Zeller, Michael D.; McQuade, Miriam M.; Garibaldi, Angela; Busch, Anke; Selwan, Elizabeth M.; Hertel, Klemens J.; Baldi, Pierre; Waterman, Marian L.

    2014-01-01

    LEF/TCFs direct the final step in Wnt/β-catenin signalling by recruiting β-catenin to genes for activation of transcription. Ancient, non-vertebrate TCFs contain two DNA binding domains, a High Mobility Group box for recognition of the Wnt Response Element (WRE; 5′-CTTTGWWS-3′) and the C-clamp domain for recognition of the GC-rich Helper motif (5′-RCCGCC-3′). Two vertebrate TCFs (TCF-1/TCF7 and TCF-4/TCF7L2) use the C-clamp as an alternatively spliced domain to regulate cell-cycle progression, but how the C-clamp influences TCF binding and activity genome-wide is not known. Here, we used a doxycycline inducible system with ChIP-seq to assess how the C-clamp influences human TCF1 binding genome-wide. Metabolic pulse-labeling of nascent RNA with 4′Thiouridine was used with RNA-seq to connect binding to the Wnt transcriptome. We find that the C-clamp enables targeting to a greater number of gene loci for stronger occupancy and transcription regulation. The C-clamp uses Helper sites concurrently with WREs for gene targeting, but it also targets TCF1 to sites that do not have readily identifiable canonical WREs. The coupled ChIP-seq/4′Thiouridine-seq analysis identified new Wnt target genes, including additional regulators of cell proliferation. Thus, C-clamp containing isoforms of TCFs are potent transcriptional regulators with an expanded transcriptome directed by C-clamp-Helper site interactions. PMID:25414359

  6. Joint Infrared Target Recognition and Segmentation Using a Shape Manifold-Aware Level Set

    PubMed Central

    Yu, Liangjiang; Fan, Guoliang; Gong, Jiulu; Havlicek, Joseph P.

    2015-01-01

    We propose new techniques for joint recognition, segmentation and pose estimation of infrared (IR) targets. The problem is formulated in a probabilistic level set framework where a shape constrained generative model is used to provide a multi-class and multi-view shape prior and where the shape model involves a couplet of view and identity manifolds (CVIM). A level set energy function is then iteratively optimized under the shape constraints provided by the CVIM. Since both the view and identity variables are expressed explicitly in the objective function, this approach naturally accomplishes recognition, segmentation and pose estimation as joint products of the optimization process. For realistic target chips, we solve the resulting multi-modal optimization problem by adopting a particle swarm optimization (PSO) algorithm and then improve the computational efficiency by implementing a gradient-boosted PSO (GB-PSO). Evaluation was performed using the Military Sensing Information Analysis Center (SENSIAC) ATR database, and experimental results show that both of the PSO algorithms reduce the cost of shape matching during CVIM-based shape inference. Particularly, GB-PSO outperforms other recent ATR algorithms, which require intensive shape matching, either explicitly (with pre-segmentation) or implicitly (without pre-segmentation). PMID:25938202

  7. Activation of wingless targets requires bipartite recognition of DNA by TCF.

    PubMed

    Chang, Mikyung V; Chang, Jinhee L; Gangopadhyay, Anu; Shearer, Andrew; Cadigan, Ken M

    2008-12-01

    Specific recognition of DNA by transcription factors is essential for precise gene regulation. In Wingless (Wg) signaling in Drosophila, target gene regulation is controlled by T cell factor (TCF), which binds to specific DNA sequences through a high mobility group (HMG) domain. However, there is considerable variability in TCF binding sites, raising the possibility that they are not sufficient for target location. Some isoforms of human TCF contain a domain, termed the C-clamp, that mediates binding to an extended sequence in vitro. However, the significance of this extended sequence for the function of Wnt response elements (WREs) is unclear. In this report, we identify a cis-regulatory element that, to our knowledge, was previously unpublished. The element, named the TCF Helper site (Helper site), is essential for the activation of several WREs. This motif greatly augments the ability of TCF binding sites to respond to Wg signaling. Drosophila TCF contains a C-clamp that enhances in vitro binding to TCF-Helper site pairs and is required for transcriptional activation of WREs containing Helper sites. A genome-wide search for clusters of TCF and Helper sites identified two new WREs. Our data suggest that DNA recognition by fly TCF occurs through a bipartite mechanism, involving both the HMG domain and the C-clamp, which enables TCF to locate and activate WREs in the nucleus. PMID:19062282

  8. Non-polymeric nano-carriers in HIV/AIDS drug delivery and targeting.

    PubMed

    Gupta, Umesh; Jain, Narendra K

    2010-03-18

    Development of an effective drug delivery approach for the treatment of HIV/AIDS is a global challenge. The conventional drug delivery approaches including Highly Active Anti Retroviral Therapy (HAART) have increased the life span of the HIV/AIDS patient. However, the eradication of HIV is still not possible with these approaches due to some limitations. Emergence of polymeric and non-polymeric nanotechnological approaches can be opportunistic in this direction. Polymeric carriers like, dendrimers and nanoparticles have been reported for the targeting of anti HIV drugs. The synthetic pathways as well polymeric framework create some hurdles in their successful formulation development as well as in the possible drug delivery approaches. In the present article, we have discussed the general physiological aspects of the infection along with the relevance of non-polymeric nanocarriers like liposomes, solid lipid nanoparticles (SLN), ethosomes, etc. in the treatment of this disastrous disease. PMID:19913579

  9. Increase in Speech Recognition Due to Linguistic Mismatch between Target and Masker Speech: Monolingual and Simultaneous Bilingual Performance

    ERIC Educational Resources Information Center

    Calandruccio, Lauren; Zhou, Haibo

    2014-01-01

    Purpose: To examine whether improved speech recognition during linguistically mismatched target-masker experiments is due to linguistic unfamiliarity of the masker speech or linguistic dissimilarity between the target and masker speech. Method: Monolingual English speakers (n = 20) and English-Greek simultaneous bilinguals (n = 20) listened to…

  10. Earth Science Data and Models for Improved Targeting of Humanitarian Aid

    NASA Technical Reports Server (NTRS)

    Brown, Molly E.

    2011-01-01

    Humanitarian assistance to developing countries has long focused on countries that have political, economic and strategic interest to the United States. Recent changes in global security concerns have heightened the perception that humanitarian action is becoming increasingly politicized. This is seen to be largely driven by the 'global war on terror' along with a push by donors and the United Nations for closer integration between humanitarian action and diplomatic, military and other spheres of engagement in conflict and crisis-affected states (HPG 2010). As we enter an era of rising commodity prices and increasing uncertainty in global food production due to a changing climate, scientific data and analysis will be increasingly important to improve the targeting of humanitarian assistance. Earth science data enables appropriate humanitarian response to complex food emergencies that arise in regions outside the areas of current strategic and security focus. As the climate changes, new places will become vulnerable to food insecurity and will need emergency assistance. Earth science data and multidisciplinary models will enable an information-based comparison of need that goes beyond strategic and political considerations to identify new hotspots of food insecurity as they emerge. These analyses will improve aid targeting and timeliness while reducing strategic risk by highlighting new regions at risk of crisis in a rapidly changing world. Improved targeting with respect to timing and location could reduce cost while increasing the likelihood that those who need aid get it.

  11. Broadening Staphylococcus aureus Cas9 Targeting Range by Modifying PAM Recognition

    PubMed Central

    Kleinstiver, Benjamin P.; Prew, Michelle S.; Tsai, Shengdar Q.; Nguyen, Nhu T.; Topkar, Ved V.; Zheng, Zongli; Joung, J. Keith

    2015-01-01

    CRISPR-Cas9 nucleases are primarily guided by RNA-DNA interactions but also require Cas9-mediated recognition of a protospacer adjacent motif (PAM). While potentially advantageous for specificity, extended PAM sequences limit the targeting range of Cas9 orthologues for genome editing. One possible strategy to relieve this restriction is to relax specificities for certain positions within the PAM. Here we used molecular evolution to modify the NNGRRT PAM specificity of Staphylococcus aureus Cas9 (SaCas9). One variant we identified, referred to as KKH SaCas9, shows robust genome editing activities at endogenous human target sites with NNNRRT PAMs. Importantly, using GUIDE-seq, we show that both wild-type and KKH SaCas9 induce comparable numbers of off-target effects in human cells. KKH SaCas9 increased the targeting range of SaCas9 by nearly two- to four-fold. Our molecular evolution strategy does not require structural information and therefore should be applicable to a wide range of Cas9 orthologues. PMID:26524662

  12. Regulation of Structural Dynamics within a Signal Recognition Particle Promotes Binding of Protein Targeting Substrates*

    PubMed Central

    Gao, Feng; Kight, Alicia D.; Henderson, Rory; Jayanthi, Srinivas; Patel, Parth; Murchison, Marissa; Sharma, Priyanka; Goforth, Robyn L.; Kumar, Thallapuranam Krishnaswamy Suresh; Henry, Ralph L.; Heyes, Colin D.

    2015-01-01

    Protein targeting is critical in all living organisms and involves a signal recognition particle (SRP), an SRP receptor, and a translocase. In co-translational targeting, interactions among these proteins are mediated by the ribosome. In chloroplasts, the light-harvesting chlorophyll-binding protein (LHCP) in the thylakoid membrane is targeted post-translationally without a ribosome. A multidomain chloroplast-specific subunit of the SRP, cpSRP43, is proposed to take on the role of coordinating the sequence of targeting events. Here, we demonstrate that cpSRP43 exhibits significant interdomain dynamics that are reduced upon binding its SRP binding partner, cpSRP54. We showed that the affinity of cpSRP43 for the binding motif of LHCP (L18) increases when cpSRP43 is complexed to the binding motif of cpSRP54 (cpSRP54pep). These results support the conclusion that substrate binding to the chloroplast SRP is modulated by protein structural dynamics in which a major role of cpSRP54 is to improve substrate binding efficiency to the cpSRP. PMID:25918165

  13. Real-time imaging systems' combination of methods to achieve automatic target recognition

    NASA Astrophysics Data System (ADS)

    Maraviglia, Carlos G.; Williams, Elmer F.; Pezzulich, Alan Z.

    1998-03-01

    Using a combination of strategies real time imaging weapons systems are achieving their goals of detecting their intended targets. The demands of acquiring a target in a cluttered environment in a timely manner with a high degree of confidence demands compromise be made as to having a truly automatic system. A combination of techniques such as dedicated image processing hardware, real time operating systems, mixes of algorithmic methods, and multi-sensor detectors are a forbearance of the unleashed potential of future weapons system and their incorporation in truly autonomous target acquisition. Elements such as position information, sensor gain controls, way marks for mid course correction, and augmentation with different imaging spectrums as well as future capabilities such as neural net expert systems and decision processors over seeing a fusion matrix architecture may be considered tools for a weapon system's achievement of its ultimate goal. Currently, acquiring a target in a cluttered environment in a timely manner with a high degree of confidence demands compromises be made as to having a truly automatic system. It is now necessary to include a human in the track decision loop, a system feature that may be long lived. Automatic Track Recognition will still be the desired goal in future systems due to the variability of military missions and desirability of an expendable asset. Furthermore, with the increasing incorporation of multi-sensor information into the track decision the human element's real time contribution must be carefully engineered.

  14. Canonical Signal Recognition Particle Components Can Be Bypassed for Posttranslational Protein Targeting in Chloroplasts[W

    PubMed Central

    Tzvetkova-Chevolleau, Tzvetelina; Hutin, Claire; Noël, Laurent D.; Goforth, Robyn; Carde, Jean-Pierre; Caffarri, Stephano; Sinning, Irmgard; Groves, Matthew; Teulon, Jean-Marie; Hoffman, Neil E.; Henry, Ralph; Havaux, Michel; Nussaume, Laurent

    2007-01-01

    The chloroplast signal recognition particle (cpSRP) and its receptor (cpFtsY) target proteins both cotranslationally and posttranslationally to the thylakoids. This dual function enables cpSRP to utilize its posttranslational activities for targeting a family of nucleus-encoded light-harvesting chlorophyll binding proteins (LHCPs), the most abundant membrane proteins in plants. Previous in vitro experiments indicated an absolute requirement for all cpSRP pathway soluble components. In agreement, a cpFtsY mutant in Arabidopsis thaliana exhibits a severe chlorotic phenotype resulting from a massive loss of LHCPs. Surprisingly, a double mutant, cpftsy cpsrp54, recovers to a great extent from the chlorotic cpftsy phenotype. This establishes that in plants, a new alternative pathway exists that can bypass cpSRP posttranslational targeting activities. Using a mutant form of cpSRP43 that is unable to assemble with cpSRP54, we complemented the cpSRP43-deficient mutant and found that this subunit is required for the alternative pathway. Along with the ability of cpSRP43 alone to bind the ALBINO3 translocase required for LHCP integration, our results indicate that cpSRP43 has developed features to function independently of cpSRP54/cpFtsY in targeting LHCPs to the thylakoid membranes. PMID:17513500

  15. Act-Up, other AIDS groups targeted for FBI surveillance. Federal Bureau of Investigations.

    PubMed

    1995-06-01

    Documents obtained by a civil rights group, the Center for Constitutional Rights, showed that the Federal Bureau of Investigations (FBI) monitored the activities of Act-Up, Gay Men's Health Crisis (GMHC), the Coalition for Lesbian and Gay Rights, and Senior Action in a Gay Environment. Act-Up was the main target from 1988 through 1992, the years it staged its most conspicuous demonstrations against the Federal government's policy on AIDS. According to one of the documents, George Bush, then president, complained about Act-Up holding protests and tossing condoms outside his summer home in Maine in 1992. The documents showed that the organization posed little threat of harm.

  16. A Compact Methodology to Understand, Evaluate, and Predict the Performance of Automatic Target Recognition

    PubMed Central

    Li, Yanpeng; Li, Xiang; Wang, Hongqiang; Chen, Yiping; Zhuang, Zhaowen; Cheng, Yongqiang; Deng, Bin; Wang, Liandong; Zeng, Yonghu; Gao, Lei

    2014-01-01

    This paper offers a compacted mechanism to carry out the performance evaluation work for an automatic target recognition (ATR) system: (a) a standard description of the ATR system's output is suggested, a quantity to indicate the operating condition is presented based on the principle of feature extraction in pattern recognition, and a series of indexes to assess the output in different aspects are developed with the application of statistics; (b) performance of the ATR system is interpreted by a quality factor based on knowledge of engineering mathematics; (c) through a novel utility called “context-probability” estimation proposed based on probability, performance prediction for an ATR system is realized. The simulation result shows that the performance of an ATR system can be accounted for and forecasted by the above-mentioned measures. Compared to existing technologies, the novel method can offer more objective performance conclusions for an ATR system. These conclusions may be helpful in knowing the practical capability of the tested ATR system. At the same time, the generalization performance of the proposed method is good. PMID:24967605

  17. Structural Code for DNA Recognition Revealed in Crystal Structures of Papillomavirus E2-DNA Targets

    NASA Astrophysics Data System (ADS)

    Rozenberg, Haim; Rabinovich, Dov; Frolow, Felix; Hegde, Rashmi S.; Shakked, Zippora

    1998-12-01

    Transcriptional regulation in papillomaviruses depends on sequence-specific binding of the regulatory protein E2 to several sites in the viral genome. Crystal structures of bovine papillomavirus E2 DNA targets reveal a conformational variant of B-DNA characterized by a roll-induced writhe and helical repeat of 10.5 bp per turn. A comparison between the free and the protein-bound DNA demonstrates that the intrinsic structure of the DNA regions contacted directly by the protein and the deformability of the DNA region that is not contacted by the protein are critical for sequence-specific protein/DNA recognition and hence for gene-regulatory signals in the viral system. We show that the selection of dinucleotide or longer segments with appropriate conformational characteristics, when positioned at correct intervals along the DNA helix, can constitute a structural code for DNA recognition by regulatory proteins. This structural code facilitates the formation of a complementary protein-DNA interface that can be further specified by hydrogen bonds and nonpolar interactions between the protein amino acids and the DNA bases.

  18. Targeting HIV clinical training with maps: lessons from the Pacific AIDS Education and Training Center.

    PubMed

    Myers, Janet; Bernstein, Mona; Morin, Stephen F; Reyes, Michael

    2007-12-01

    Public health providers are increasingly called on to do more with fewer resources. Aiming to help HIV clinical training providers in 15 local sites to better target their efforts, the Pacific AIDS Education and Training Center (PAETC) implemented a method for integrating disparate information, such as program-level evaluation and publicly available health services data, into one combined and useful format. The resulting local area profiles were distributed to each training site and were updated annually for 2 years. As a result, local training teams adopted data-based approaches to doing their work. Training managers and faculty reported that data presented in spatial formats (i.e., maps) were most helpful for targeting their outreach and training. In addition to achieving the aim of supporting better programs, the project increased capacity for using data to support all aspects of training and education, from grant writing to strategic planning.

  19. A distributed automatic target recognition system using multiple low resolution sensors

    NASA Astrophysics Data System (ADS)

    Yue, Zhanfeng; Lakshmi Narasimha, Pramod; Topiwala, Pankaj

    2008-04-01

    In this paper, we propose a multi-agent system which uses swarming techniques to perform high accuracy Automatic Target Recognition (ATR) in a distributed manner. The proposed system can co-operatively share the information from low-resolution images of different looks and use this information to perform high accuracy ATR. An advanced, multiple-agent Unmanned Aerial Vehicle (UAV) systems-based approach is proposed which integrates the processing capabilities, combines detection reporting with live video exchange, and swarm behavior modalities that dramatically surpass individual sensor system performance levels. We employ real-time block-based motion analysis and compensation scheme for efficient estimation and correction of camera jitter, global motion of the camera/scene and the effects of atmospheric turbulence. Our optimized Partition Weighted Sum (PWS) approach requires only bitshifts and additions, yet achieves a stunning 16X pixel resolution enhancement, which is moreover parallizable. We develop advanced, adaptive particle-filtering based algorithms to robustly track multiple mobile targets by adaptively changing the appearance model of the selected targets. The collaborative ATR system utilizes the homographies between the sensors induced by the ground plane to overlap the local observation with the received images from other UAVs. The motion of the UAVs distorts estimated homography frame to frame. A robust dynamic homography estimation algorithm is proposed to address this, by using the homography decomposition and the ground plane surface estimation.

  20. Dynamic Data Driven Applications Systems (DDDAS) modeling for automatic target recognition

    NASA Astrophysics Data System (ADS)

    Blasch, Erik; Seetharaman, Guna; Darema, Frederica

    2013-05-01

    The Dynamic Data Driven Applications System (DDDAS) concept uses applications modeling, mathematical algorithms, and measurement systems to work with dynamic systems. A dynamic systems such as Automatic Target Recognition (ATR) is subject to sensor, target, and the environment variations over space and time. We use the DDDAS concept to develop an ATR methodology for multiscale-multimodal analysis that seeks to integrated sensing, processing, and exploitation. In the analysis, we use computer vision techniques to explore the capabilities and analogies that DDDAS has with information fusion. The key attribute of coordination is the use of sensor management as a data driven techniques to improve performance. In addition, DDDAS supports the need for modeling from which uncertainty and variations are used within the dynamic models for advanced performance. As an example, we use a Wide-Area Motion Imagery (WAMI) application to draw parallels and contrasts between ATR and DDDAS systems that warrants an integrated perspective. This elementary work is aimed at triggering a sequence of deeper insightful research towards exploiting sparsely sampled piecewise dense WAMI measurements - an application where the challenges of big-data with regards to mathematical fusion relationships and high-performance computations remain significant and will persist. Dynamic data-driven adaptive computations are required to effectively handle the challenges with exponentially increasing data volume for advanced information fusion systems solutions such as simultaneous target tracking and ATR.

  1. A robust algorithm for automated target recognition using precomputed radar cross sections

    NASA Astrophysics Data System (ADS)

    Ehrman, Lisa M.; Lanterman, Aaron D.

    2004-09-01

    Passive radar is an emerging technology that offers a number of unique benefits, including covert operation. Many such systems are already capable of detecting and tracking aircraft. The goal of this work is to develop a robust algorithm for adding automated target recognition (ATR) capabilities to existing passive radar systems. In previous papers, we proposed conducting ATR by comparing the precomputed RCS of known targets to that of detected targets. To make the precomputed RCS as accurate as possible, a coordinated flight model is used to estimate aircraft orientation. Once the aircraft's position and orientation are known, it is possible to determine the incident and observed angles on the aircraft, relative to the transmitter and receiver. This makes it possible to extract the appropriate radar cross section (RCS) from our simulated database. This RCS is then scaled to account for propagation losses and the receiver's antenna gain. A Rician likelihood model compares these expected signals from different targets to the received target profile. We have previously employed Monte Carlo runs to gauge the probability of error in the ATR algorithm; however, generation of a statistically significant set of Monte Carlo runs is computationally intensive. As an alternative to Monte Carlo runs, we derive the relative entropy (also known as Kullback-Liebler distance) between two Rician distributions. Since the probability of Type II error in our hypothesis testing problem can be expressed as a function of the relative entropy via Stein's Lemma, this provides us with a computationally efficient method for determining an upper bound on our algorithm's performance. It also provides great insight into the types of classification errors we can expect from our algorithm. This paper compares the numerically approximated probability of Type II error with the results obtained from a set of Monte Carlo runs.

  2. Electrochemical aptameric recognition system for a sensitive protein assay based on specific target binding-induced rolling circle amplification.

    PubMed

    Wu, Zai-Sheng; Zhou, Hui; Zhang, Songbai; Shen, Guoli; Yu, Ruqin

    2010-03-15

    A reusable aptameric recognition system was described for the electrochemical detection of the protein PDGF-BB based on the target binding-induced rolling circle amplification (RCA). A complementary DNA (CDNA), linear padlock probe, and primer probe were utilized to introduce a RCA process into the aptamer-target binding event while a new aptamer was elegantly designed via lengthening the original aptamer by the complement to the CDNA. The aptameric sensing system facilitates the integration of multiple functional elements into a signaling scheme: a unique electrochemical technique, an attractive RCA process, reversible DNA hybridization, and desirable aptameric target recognition. This RCA-based electrochemical recognition system not only exhibits excellent performance (e.g., a detection limit of 6.3 x 10(-11) M, a linear dynamic range of 2 orders of magnitude, high specificity, and satisfactory repeatability) but also overcomes the limitations associated with conventional aptameric biosensors (e.g., dependence of signaling target binding on specific aptamer sequence or requirement of sandwich assays for two or more binding sites per target molecule). A recovery test demonstrated the feasibility of the developed target protein assay. Given the attractive characteristics, this aptameric recognition platform is expected to be a candidate for the detection of proteins and other ligands of interest in both fundamental and applied research.

  3. Computer-aided Molecular Design of Compounds Targeting Histone Modifying Enzymes

    PubMed Central

    Andreoli, Federico; Del Rio, Alberto

    2015-01-01

    Growing evidences show that epigenetic mechanisms play crucial roles in the genesis and progression of many physiopathological processes. As a result, research in epigenetic grew at a fast pace in the last decade. In particular, the study of histone post-translational modifications encountered an extraordinary progression and many modifications have been characterized and associated to fundamental biological processes and pathological conditions. Histone modifications are the catalytic result of a large set of enzyme families that operate covalent modifications on specific residues at the histone tails. Taken together, these modifications elicit a complex and concerted processing that greatly contribute to the chromatin remodeling and may drive different pathological conditions, especially cancer. For this reason, several epigenetic targets are currently under validation for drug discovery purposes and different academic and industrial programs have been already launched to produce the first pre-clinical and clinical outcomes. In this scenario, computer-aided molecular design techniques are offering important tools, mainly as a consequence of the increasing structural information available for these targets. In this mini-review we will briefly discuss the most common types of known histone modifications and the corresponding operating enzymes by emphasizing the computer-aided molecular design approaches that can be of use to speed-up the efforts to generate new pharmaceutically relevant compounds. PMID:26082827

  4. Computer-aided Molecular Design of Compounds Targeting Histone Modifying Enzymes.

    PubMed

    Andreoli, Federico; Del Rio, Alberto

    2015-01-01

    Growing evidences show that epigenetic mechanisms play crucial roles in the genesis and progression of many physiopathological processes. As a result, research in epigenetic grew at a fast pace in the last decade. In particular, the study of histone post-translational modifications encountered an extraordinary progression and many modifications have been characterized and associated to fundamental biological processes and pathological conditions. Histone modifications are the catalytic result of a large set of enzyme families that operate covalent modifications on specific residues at the histone tails. Taken together, these modifications elicit a complex and concerted processing that greatly contribute to the chromatin remodeling and may drive different pathological conditions, especially cancer. For this reason, several epigenetic targets are currently under validation for drug discovery purposes and different academic and industrial programs have been already launched to produce the first pre-clinical and clinical outcomes. In this scenario, computer-aided molecular design techniques are offering important tools, mainly as a consequence of the increasing structural information available for these targets. In this mini-review we will briefly discuss the most common types of known histone modifications and the corresponding operating enzymes by emphasizing the computer-aided molecular design approaches that can be of use to speed-up the efforts to generate new pharmaceutically relevant compounds.

  5. Structural Insights Into the Recognition of Peroxisomal Targeting Signal 1 By Trypanosoma Brucei Peroxin 5

    SciTech Connect

    Sampathkumar, P.; Roach, C.; Michels, P.A.M.; Hol, W.G.J.

    2009-05-27

    Glycosomes are peroxisome-like organelles essential for trypanosomatid parasites. Glycosome biogenesis is mediated by proteins called 'peroxins,' which are considered to be promising drug targets in pathogenic Trypanosomatidae. The first step during protein translocation across the glycosomal membrane of peroxisomal targeting signal 1 (PTS1)-harboring proteins is signal recognition by the cytosolic receptor peroxin 5 (PEX5). The C-terminal PTS1 motifs interact with the PTS1 binding domain (P1BD) of PEX5, which is made up of seven tetratricopeptide repeats. Obtaining diffraction-quality crystals of the P1BD of Trypanosoma brucei PEX5 (TbPEX5) required surface entropy reduction mutagenesis. Each of the seven tetratricopeptide repeats appears to have a residue in the alpha(L) conformation in the loop connecting helices A and B. Five crystal structures of the P1BD of TbPEX5 were determined, each in complex with a hepta- or decapeptide corresponding to a natural or nonnatural PTS1 sequence. The PTS1 peptides are bound between the two subdomains of the P1BD. These structures indicate precise recognition of the C-terminal Leu of the PTS1 motif and important interactions between the PTS1 peptide main chain and up to five invariant Asn side chains of PEX5. The TbPEX5 structures reported here reveal a unique hydrophobic pocket in the subdomain interface that might be explored to obtain compounds that prevent relative motions of the subdomains and interfere selectively with PTS1 motif binding or release in trypanosomatids, and would therefore disrupt glycosome biogenesis and prevent parasite growth.

  6. Computer-aided lung nodule recognition by SVM classifier based on combination of random undersampling and SMOTE.

    PubMed

    Sui, Yuan; Wei, Ying; Zhao, Dazhe

    2015-01-01

    In lung cancer computer-aided detection/diagnosis (CAD) systems, classification of regions of interest (ROI) is often used to detect/diagnose lung nodule accurately. However, problems of unbalanced datasets often have detrimental effects on the performance of classification. In this paper, both minority and majority classes are resampled to increase the generalization ability. We propose a novel SVM classifier combined with random undersampling (RU) and SMOTE for lung nodule recognition. The combinations of the two resampling methods not only achieve a balanced training samples but also remove noise and duplicate information in the training sample and retain useful information to improve the effective data utilization, hence improving performance of SVM algorithm for pulmonary nodules classification under the unbalanced data. Eight features including 2D and 3D features are extracted for training and classification. Experimental results show that for different sizes of training datasets our RU-SMOTE-SVM classifier gets the highest classification accuracy among the four kinds of classifiers, and the average classification accuracy is more than 92.94%. PMID:25977704

  7. Computer-Aided Lung Nodule Recognition by SVM Classifier Based on Combination of Random Undersampling and SMOTE

    PubMed Central

    Sui, Yuan; Wei, Ying; Zhao, Dazhe

    2015-01-01

    In lung cancer computer-aided detection/diagnosis (CAD) systems, classification of regions of interest (ROI) is often used to detect/diagnose lung nodule accurately. However, problems of unbalanced datasets often have detrimental effects on the performance of classification. In this paper, both minority and majority classes are resampled to increase the generalization ability. We propose a novel SVM classifier combined with random undersampling (RU) and SMOTE for lung nodule recognition. The combinations of the two resampling methods not only achieve a balanced training samples but also remove noise and duplicate information in the training sample and retain useful information to improve the effective data utilization, hence improving performance of SVM algorithm for pulmonary nodules classification under the unbalanced data. Eight features including 2D and 3D features are extracted for training and classification. Experimental results show that for different sizes of training datasets our RU-SMOTE-SVM classifier gets the highest classification accuracy among the four kinds of classifiers, and the average classification accuracy is more than 92.94%. PMID:25977704

  8. Basaltic Magma-Water Interaction on Earth: Recognition Criteria To Aid Planetary Mapping on Mars (Invited)

    NASA Astrophysics Data System (ADS)

    Skilling, I. P.; Graettinger, A. H.; Mercurio, E.; McGarvie, D.; Edwards, B. R.

    2013-12-01

    The interaction of basaltic magma with frozen/liquid water or wet sediment is a very common process on Earth, resulting in a wide array of explosively and non-explosively generated products at the micron to kilometre scale. A variety of products and edifices on Mars have also been interpreted as having formed by such interaction, but with the exception of rootless cones, such interpretations are rarely unequivocal. This talk focuses on terrestrial process recognition criteria at a scale, orientation (vertical) and erosion level that is relevant to Mars geological mapping. In this context, we emphasise intrusions with peperite margins and wide hydrothermal haloes, steep margins of ice-contact lava flows, subaerial-subaqueous lava delta transitions, lava domains with distinctive water-cooled jointing, edifices that are dominated by slumped and rotated beds, and the presence of surrounding fluvial deposits and erosion. The most common products of magma-water interaction on Earth are subaqueously emplaced lava flows, which are dominated by pillow lavas. Though pillows are not easy to distinguish from subaerial pahoehoe toes at the resolution of most remote imagery, they are commonly associated with distinctively jointed lava domains, which are usually on a larger scale, including areas of water-cooled jointing (curvicolumnar, blocky etc), lava-filled tubes, which often display radial jointing, and steep talus deposits of joint-block breccia. Subaqueous basaltic lavas emplaced in an ice-confined environment may also display near-vertical ice-contact margins, draped by curtains of elongate pillows or cavities formed from melting of included ice-blocks. Subaerial lava flows that transition into water also develop large-scale foreset-bedding close to the angle of repose, which should be easily visible, at least in oblique imagery. As the majority of the Martian surface is more deeply eroded than most areas of terrestrial basaltic volcanism, it is important to discuss

  9. Comparison of optimization-algorithm based feature extraction from time data or time-frequency data for target recognition purposes

    NASA Astrophysics Data System (ADS)

    Strifors, H. C.; Abrahamson, S.; Andersson, T.; Gaunaurd, G. C.

    2006-05-01

    Ultra-wideband ground penetrating radar (GPR) systems have proved useful for extracting and displaying information for target recognition purposes. Target signatures whether in the time, frequency, or joint time-frequency domains, will substantially depend on the target's burial conditions such as the type of soil, burial depth, and the soil's moisture content. That dependence can be utilized for target recognition purposes as we have demonstrated previously. The signature template of each target was computed in the time-frequency domain from the returned echo when the target was buried at a known depth in the soil with a known moisture content. Then, for any returned echo the relative difference between the similarly computed target signature and a selected signature template was computed. A global optimization method together with our (approximate) target translation method (TTM) that signature difference, chosen as object function, was minimized by adjusting the depth and moisture content, now taken to be unknown parameters. The template that gave the smallest value of the minimized object function for the returned echo was taken as target classification and the corresponding values of the depth and moisture parameters as estimates of the target's burial conditions. This optimization technique can also be applied to time-series data, avoiding the need for time-frequency analysis. It is then of interest to evaluate the relative merits of time data and time-frequency data for target recognition. Such a comparison is here preformed using signals returned from dummy mines buried underground. The results of the analysis serve to assess the intrinsic worth of data in the time domain and in the time-frequency domain for identifying subsurface targets using a GPR. The targets are buried in a test field at the Swedish Explosive Ordnance Disposal and Demining Center (SWEDEC) at Eksjo, Sweden.

  10. Efficacy of social cognition remediation programs targeting facial affect recognition deficits in schizophrenia: a review and consideration of high-risk samples and sex differences.

    PubMed

    Statucka, Marta; Walder, Deborah J

    2013-04-30

    Schizophrenia patients suffer from significant social functioning deficits. Social cognition, particularly facial affect recognition (FAR), is an important predictor of functional outcome. Recently, investigators developed numerous social cognition remediation programs targeting FAR deficits with the goal of improving social functioning and quality of life in schizophrenia patients. This article builds on Horan et al.'s (2008) comprehensive review and Kurtz and Richardson's (2012) meta-analysis of a broad range of social cognition remediations, by systematically reviewing efficacy of empirically based remediations in schizophrenia specifically targeting FAR (across 23 studies), and their potential functional benefits. We describe each FAR-based social cognition remediation program, which may aid clinical scientists and clinicians in selecting programs for further study and practice. We critically evaluate limitations of FAR remediation programs and applications. Our review concludes FAR remediation programs are strongly efficacious in improving FAR performance and functional status in schizophrenia. Importantly, we provide rationale for and recommend that future research consider (as yet underexplored) sexual dimorphisms in FAR remediation effects, and examine FAR remediation in clinical high-risk for psychosis populations. The goal is to mitigate deficits, perhaps hinder illness onset, and individually tailor treatments across the psychosis continuum in a way that maximally aids those in greatest need.

  11. A novel molecular beacon-based method for isothermal detection of sequence-specific DNA via T7 RNA polymerase-aided target regeneration.

    PubMed

    Yin, Bin-Cheng; Wu, Shan; Ma, Jin-Liang; Ye, Bang-Ce

    2015-06-15

    Developing molecular beacon (MB)-based method for DNA detection has been of great interest to many researchers because of its intrinsic advantages of simplicity, rapidity, and specificity. In this work, we have developed a novel MB-based method for isothermal detection of sequence-specific DNA via T7 RNA polymerase-aided target regeneration strategy. The proposed method involves three primary processes of target-mediated ligation by T4 DNA ligase, transcription reaction by T7 RNA polymerase, and MB switch for signal output. Upon the hybridization with DNA target, a rationally designed MB and a pair of primers encoded with T7 promoter sequence were ligated via the formation of a phosphodiester bond by T4 DNA ligase. The resultant joint fragment acted as template to initiate T7 RNA polymerase-mediated transcription reaction. Correspondingly, a great amount of RNA strands complementary to MB and partial primers were transcribed to initiate new cyclic reactions of MB switch, ligation, and transcription. With such signal amplification strategy of the regeneration of target-like RNA fragments, our proposed assay achieved a detection limit as low as ∼10 pM, which was ∼3 orders of magnitude lower than the traditional MB-based method with a recognition mechanism in 1:1 stoichiometric ratio between MB and target molecule.

  12. Mechanism of CRISPR-RNA guided recognition of DNA targets in Escherichia coli.

    PubMed

    van Erp, Paul B G; Jackson, Ryan N; Carter, Joshua; Golden, Sarah M; Bailey, Scott; Wiedenheft, Blake

    2015-09-30

    In bacteria and archaea, short fragments of foreign DNA are integrated into Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR) loci, providing a molecular memory of previous encounters with foreign genetic elements. In Escherichia coli, short CRISPR-derived RNAs are incorporated into a multi-subunit surveillance complex called Cascade (CRISPR-associated complex for antiviral defense). Recent structures of Cascade capture snapshots of this seahorse-shaped RNA-guided surveillance complex before and after binding to a DNA target. Here we determine a 3.2 Å x-ray crystal structure of Cascade in a new crystal form that provides insight into the mechanism of double-stranded DNA binding. Molecular dynamic simulations performed using available structures reveal functional roles for residues in the tail, backbone and belly subunits of Cascade that are critical for binding double-stranded DNA. Structural comparisons are used to make functional predictions and these predictions are tested in vivo and in vitro. Collectively, the results in this study reveal underlying mechanisms involved in target-induced conformational changes and highlight residues important in DNA binding and protospacer adjacent motif recognition.

  13. Study on the recognition of camouflage targets with hyper-spectral detection

    NASA Astrophysics Data System (ADS)

    Wang, Jia-chun; Wang, Qi-chao; Lin, Zhi-dan; Zhao, Da-peng; Shi, Jia-ming; Chen, Zong-sheng

    2015-10-01

    In order to acquire more information of the scene to improve the veracity of recognition of camouflage targets, an electrically tunable hyper-spectral detection system, which is based on acousto-optic tunable filter (AOTF), was designed. The system includes collimated optical system, AOTF and its controller, imaging lens, CCD sensor and so on. The system has a property of being fast and electronically tunable, so a quick scan of spectrum over the waveband of 550 nm ~ 900nm can be realized. A series of hyper-spectral imaging experiments about a camouflage aluminum plane, coated with three typical camouflage pigments (dark green, light green and khaki) within a complex meadow environment were accomplished at specific wavelengths from 580 nm to 840 nm with 10 nm spectral resolution. The hyper-spectral characteristics of three pigments and various backgrounds were acquired to deduce the intensity contrast information between them. The experimental results demonstrated that the reflex characteristic of three typical camouflage pigments were different from that of natural background. The several wavelengths or wave bands, which were used to detect and recognize the man-made targets placed in typical woodland environment, were obtained by analyzing the experimental data.

  14. Mechanism of CRISPR-RNA guided recognition of DNA targets in Escherichia coli

    PubMed Central

    van Erp, Paul B.G.; Jackson, Ryan N.; Carter, Joshua; Golden, Sarah M.; Bailey, Scott; Wiedenheft, Blake

    2015-01-01

    In bacteria and archaea, short fragments of foreign DNA are integrated into Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR) loci, providing a molecular memory of previous encounters with foreign genetic elements. In Escherichia coli, short CRISPR-derived RNAs are incorporated into a multi-subunit surveillance complex called Cascade (CRISPR-associated complex for antiviral defense). Recent structures of Cascade capture snapshots of this seahorse-shaped RNA-guided surveillance complex before and after binding to a DNA target. Here we determine a 3.2 Å x-ray crystal structure of Cascade in a new crystal form that provides insight into the mechanism of double-stranded DNA binding. Molecular dynamic simulations performed using available structures reveal functional roles for residues in the tail, backbone and belly subunits of Cascade that are critical for binding double-stranded DNA. Structural comparisons are used to make functional predictions and these predictions are tested in vivo and in vitro. Collectively, the results in this study reveal underlying mechanisms involved in target-induced conformational changes and highlight residues important in DNA binding and protospacer adjacent motif recognition. PMID:26243775

  15. Chemiresistive and Gravimetric Dual-Mode Gas Sensor toward Target Recognition and Differentiation.

    PubMed

    Chen, Yan; Zhang, Hao; Feng, Zhihong; Zhang, Hongxiang; Zhang, Rui; Yu, Yuanyuan; Tao, Jin; Zhao, Hongyuan; Guo, Wenlan; Pang, Wei; Duan, Xuexin; Liu, Jing; Zhang, Daihua

    2016-08-24

    We demonstrate a dual-mode gas sensor for simultaneous and independent acquisition of electrical and mechanical signals from the same gas adsorption event. The device integrates a graphene field-effect transistor (FET) with a piezoelectric resonator in a seamless manner by leveraging multiple structural and functional synergies. Dual signals resulting from independent physical processes, i.e., mass attachment and charge transfer can reflect intrinsic properties of gas molecules and potentially enable target recognition and quantification at the same time. Fabrication of the device is based on standard Integrated Circuit (IC) foundry processes and fully compatible with system-on-a-chip (SoC) integration to achieve extremely small form factors. In addition, the ability of simultaneous measurements of mass adsorption and charge transfer guides us to a more precise understanding of the interactions between graphene and various gas molecules. Besides its practical functions, the device serves as an effective tool to quantitatively investigate the physical processes and sensing mechanisms for a large library of sensing materials and target analytes. PMID:27455947

  16. Computational integral-imaging reconstruction-based 3-D volumetric target object recognition by using a 3-D reference object.

    PubMed

    Kim, Seung-Cheol; Park, Seok-Chan; Kim, Eun-Soo

    2009-12-01

    In this paper, we propose a novel computational integral-imaging reconstruction (CIIR)-based three-dimensional (3-D) image correlator system for the recognition of 3-D volumetric objects by employing a 3-D reference object. That is, a number of plane object images (POIs) computationally reconstructed from the 3-D reference object are used for the 3-D volumetric target recognition. In other words, simultaneous 3-D image correlations between two sets of target and reference POIs, which are depth-dependently reconstructed by using the CIIR method, are performed for effective recognition of 3-D volumetric objects in the proposed system. Successful experiments with this CIIR-based 3-D image correlator confirmed the feasibility of the proposed method.

  17. Target-context unitization effect on the familiarity-related FN400: a face recognition exclusion task.

    PubMed

    Guillaume, Fabrice; Etienne, Yann

    2015-03-01

    Using two exclusion tasks, the present study examined how the ERP correlates of face recognition are affected by the nature of the information to be retrieved. Intrinsic (facial expression) and extrinsic (background scene) visual information were paired with face identity and constituted the exclusion criterion at test time. Although perceptual information had to be taken into account in both situations, the FN400 old-new effect was observed only for old target faces on the expression-exclusion task, whereas it was found for both old target and old non-target faces in the background-exclusion situation. These results reveal that the FN400, which is generally interpreted as a correlate of familiarity, was modulated by the retrieval of intra-item and intrinsic face information, but not by the retrieval of extrinsic information. The observed effects on the FN400 depended on the nature of the information to be retrieved and its relationship (unitization) to the recognition target. On the other hand, the parietal old-new effect (generally described as an ERP correlate of recollection) reflected the retrieval of both types of contextual features equivalently. The current findings are discussed in relation to recent controversies about the nature of the recognition processes reflected by the ERP correlates of face recognition.

  18. Investigation of measureable parameters that correlate with automatic target recognition performance in synthetic aperture sonar

    NASA Astrophysics Data System (ADS)

    Gazagnaire, Julia; Cobb, J. T.; Isaacs, Jason

    2015-05-01

    There is a desire in the Mine Counter Measure community to develop a systematic method to predict and/or estimate the performance of Automatic Target Recognition (ATR) algorithms that are detecting and classifying mine-like objects within sonar data. Ideally, parameters exist that can be measured directly from the sonar data that correlate with ATR performance. In this effort, two metrics were analyzed for their predictive potential using high frequency synthetic aperture sonar (SAS) images. The first parameter is a measure of contrast. It is essentially the variance in pixel intensity over a fixed partition of relatively small size. An analysis was performed to determine the optimum block size for this contrast calculation. These blocks were then overlapped in the horizontal and vertical direction over the entire image. The second parameter is the one-dimensional K-shape parameter. The K-distribution is commonly used to describe sonar backscatter return from range cells that contain a finite number of scatterers. An Ada-Boosted Decision Tree classifier was used to calculate the probability of classification (Pc) and false alarm rate (FAR) for several types of targets in SAS images from three different data sets. ROC curves as a function of the measured parameters were generated and the correlation between the measured parameters in the vicinity of each of the contacts and the ATR performance was investigated. The contrast and K-shape parameters were considered separately. Additionally, the contrast and K-shape parameter were associated with background texture types using previously labeled high frequency SAS images.

  19. Synthetic heterovalent inhibitors targeting recognition E3 components of the N-end rule pathway.

    PubMed

    Lee, Min Jae; Pal, Krishnendu; Tasaki, Takafumi; Roy, Sayantani; Jiang, Yonghua; An, Jee Young; Banerjee, Rajkumar; Kwon, Yong Tae

    2008-01-01

    Multivalent binding allows high selectivity and affinity in a ligand-protein interaction. The N-end rule pathway is a ubiquitin (Ub)-dependent proteolytic system in which specific E3s, called N-recognins, mediate ubiquitylation through the recognition of types 1 and 2, destabilizing N-terminal residues of substrates. We recently identified a set of E3 Ub ligases (named UBR1-UBR7) containing the 70-residue UBR box, and we demonstrated that UBR1, UBR2, UBR4, and UBR5 can bind to destabilizing N-terminal residues. To explore a model of heterovalent interaction to the N-recognin family, we synthesized the small-molecule compound RF-C11, which bears two heterovalent ligands designed to target N-recognins, together with control molecules with two homovalent ligands. We demonstrate that heterovalent ligands of RF-C11 selectively and cooperatively bind cognate-binding sites of multiple N-recognins and thereby inhibit both types 1 and 2 N-end rule activities. Furthermore, the efficacy of heterovalent RF-C11 was substantially higher than homovalent inhibitors, which can target either a type 1 or type 2 site, providing the molecular basis of designing multivalent inhibitors for the control of specific intracellular pathways. In addition, RF-C11 exhibited higher efficacy and stability, compared with dipeptides bearing destabilizing N-terminal residues, which are known competitive inhibitors of the pathway. We also used the heterovalent compound to study the function of N-recognins in cardiac signaling. Using mouse and rat cardiomyocytes, we demonstrate that the N-end rule pathway has a cell-autonomous function in cardiac proliferation and hypertrophy, explaining our earlier results implicating the pathway in cardiac development and proteolysis of multiple cardiovascular regulators. PMID:18162545

  20. Proposed docking interface between peptidoglycan and the target recognition domain of zoocin A

    SciTech Connect

    Chen, Yinghua; Simmonds, Robin S.; Timkovich, Russell

    2013-11-15

    Highlights: •Peptidoglycan added to zoocin rTRD perturbs NMR resonances around W115. •Simulations predict docking to a shallow surface groove near W115. •The docking interface is similar to mammalian antibody–antigen sites. •EDTA binds to a distinct surface site. -- Abstract: A docking model is proposed for the target recognition domain of the lytic exoenzyme zoocin A with the peptidoglycan on the outer cell surface of sensitive bacterial strains. Solubilized fragments from such peptidoglycans perturb specific backbone and side chain amide resonances in the recombinant form of the domain designated rTRD as detected in two-dimensional {sup 1}H–{sup 15}N correlation NMR spectra. The affected residues comprise a shallow surface cleft on the protein surface near W115, N53, N117, and Q105 among others, which interacts with the peptide portion of the peptidoglycan. Calculations with AutoDock Vina provide models of the docking interface. There is approximate homology between the rTDR-peptidoglycan docking site and the antigen binding site of Fab antibodies with the immunoglobin fold. EDTA was also found to bind to rTRD, but at a site distinct from the proposed peptidoglycan docking site.

  1. Contextual action recognition and target localization with an active allocation of attention on a humanoid robot.

    PubMed

    Ognibene, Dimitri; Chinellato, Eris; Sarabia, Miguel; Demiris, Yiannis

    2013-09-01

    Exploratory gaze movements are fundamental for gathering the most relevant information regarding the partner during social interactions. Inspired by the cognitive mechanisms underlying human social behaviour, we have designed and implemented a system for a dynamic attention allocation which is able to actively control gaze movements during a visual action recognition task exploiting its own action execution predictions. Our humanoid robot is able, during the observation of a partner's reaching movement, to contextually estimate the goal position of the partner's hand and the location in space of the candidate targets. This is done while actively gazing around the environment, with the purpose of optimizing the gathering of information relevant for the task. Experimental results on a simulated environment show that active gaze control, based on the internal simulation of actions, provides a relevant advantage with respect to other action perception approaches, both in terms of estimation precision and of time required to recognize an action. Moreover, our model reproduces and extends some experimental results on human attention during an action perception.

  2. Non-Cooperative Target Recognition by Means of Singular Value Decomposition Applied to Radar High Resolution Range Profiles †

    PubMed Central

    López-Rodríguez, Patricia; Escot-Bocanegra, David; Fernández-Recio, Raúl; Bravo, Ignacio

    2015-01-01

    Radar high resolution range profiles are widely used among the target recognition community for the detection and identification of flying targets. In this paper, singular value decomposition is applied to extract the relevant information and to model each aircraft as a subspace. The identification algorithm is based on angle between subspaces and takes place in a transformed domain. In order to have a wide database of radar signatures and evaluate the performance, simulated range profiles are used as the recognition database while the test samples comprise data of actual range profiles collected in a measurement campaign. Thanks to the modeling of aircraft as subspaces only the valuable information of each target is used in the recognition process. Thus, one of the main advantages of using singular value decomposition, is that it helps to overcome the notable dissimilarities found in the shape and signal-to-noise ratio between actual and simulated profiles due to their difference in nature. Despite these differences, the recognition rates obtained with the algorithm are quite promising. PMID:25551484

  3. Targeting AIDS through information, education, and communications programs: implications for Africa and the Caribbean.

    PubMed

    Ward, W B

    1989-01-01

    IEC campaigns targeted at acquired immunodeficiency syndrome (AIDS) must seek to achieve the maximum impact within a contest of extremely limited resources. This implies a careful assessment of population groups and behaviors that carry the highest risk. Rather than expending large sums of money on mass media campaigns, the approach should be to target IEC activities at the social networks of those most at risk. This may include, for example, prostitutes, homosexual men, hotel and tourist employees, students, and military personnel. Once epidemiologic studies have identified the at-risk population, volunteers form these groups should be recruited and trained to reach their peers through the networks available to them. This education component of IEC work takes priority. The second step involves information diffusion to health providers who are likely to come into contact with human immunodeficiency virus (HIV)-infected individuals, especially those who have access to pregnant women and mothers. Some of these providers are not aware of the risks involved in the reuse of immunization needles. The third step--communication with the general public--is aimed at making the population aware of the factors that place people at risk of HIV infection. Radio seems to be the media capable of reaching the greatest numbers, although traditional means of communication should not be neglected. The IEC effort should consider options at the community, institutional, and individual levels and address those factors that enable, reinforce, and predispose appropriate health behaviors.

  4. Comparison of an 'intuitive' NHS hearing aid prescription method with DSL 4.1 targets for amplification.

    PubMed

    Parsons, Jonathan O; Clark, Charles R

    2002-09-01

    This study aimed to evaluate current practice in a National Health Service Trust in setting hearing aid output to meet amplification targets prescribed by desired sensation level (DSL) using a range of NHS hearing aids. A consecutive sample of 33 patients was drawn from the hearing aid waiting list of the Royal Devon & Exeter Hospital (RD&E). The age range was 33-83 years. Patients not giving written consent and those with complex hearing losses were excluded. At review, pure-tone audiogram, uncomfortable loudness levels, real-ear coupler difference, user gain and maximum output were recorded. Data were entered into DSL 4.1 prescription software. Wilcoxon tests were used to compare the measured user gain and maximum output with DSL 4.1-generated targets. The results demonstrate significant differences (p<0.05) at 0.25, 0.5, 0.75, 1.5, 2, 3, 4 and 6 kHz between target and measured values for user gain. This study reveals that the routine intuitive method for prescribing hearing aids at the RD&E is not effective in meeting targets for amplified speech as prescribed by DSL.

  5. Understanding the structural basis of substrate recognition by Plasmodium falciparum plasmepsin V to aid in the design of potent inhibitors.

    PubMed

    Bedi, Rajiv K; Patel, Chandan; Mishra, Vandana; Xiao, Huogen; Yada, Rickey Y; Bhaumik, Prasenjit

    2016-01-01

    Plasmodium falciparum plasmepsin V (PfPMV) is an essential aspartic protease required for parasite survival, thus, considered as a potential drug target. This study reports the first detailed structural analysis and molecular dynamics simulation of PfPMV as an apoenzyme and its complexes with the substrate PEXEL as well as with the inhibitor saquinavir. The presence of pro-peptide in PfPMV may not structurally hinder the formation of a functionally competent catalytic active site. The structure of PfPMV-PEXEL complex shows that the unique positions of Glu179 and Gln222 are responsible for providing the specificity of PEXEL substrate with arginine at P3 position. The structural analysis also reveals that the S4 binding pocket in PfPMV is occupied by Ile94, Ala98, Phe370 and Tyr472, and therefore, does not allow binding of pepstatin, a potent inhibitor of most pepsin-like aspartic proteases. Among the screened inhibitors, the HIV-1 protease inhibitors and KNI compounds have higher binding affinities for PfPMV with saquinavir having the highest value. The presence of a flexible group at P2 and a bulky hydrophobic group at P3 position of the inhibitor is preferred in the PfPMV substrate binding pocket. Results from the present study will aid in the design of potent inhibitors of PMV. PMID:27531685

  6. Understanding the structural basis of substrate recognition by Plasmodium falciparum plasmepsin V to aid in the design of potent inhibitors

    PubMed Central

    Bedi, Rajiv K.; Patel, Chandan; Mishra, Vandana; Xiao, Huogen; Yada, Rickey Y.; Bhaumik, Prasenjit

    2016-01-01

    Plasmodium falciparum plasmepsin V (PfPMV) is an essential aspartic protease required for parasite survival, thus, considered as a potential drug target. This study reports the first detailed structural analysis and molecular dynamics simulation of PfPMV as an apoenzyme and its complexes with the substrate PEXEL as well as with the inhibitor saquinavir. The presence of pro-peptide in PfPMV may not structurally hinder the formation of a functionally competent catalytic active site. The structure of PfPMV-PEXEL complex shows that the unique positions of Glu179 and Gln222 are responsible for providing the specificity of PEXEL substrate with arginine at P3 position. The structural analysis also reveals that the S4 binding pocket in PfPMV is occupied by Ile94, Ala98, Phe370 and Tyr472, and therefore, does not allow binding of pepstatin, a potent inhibitor of most pepsin-like aspartic proteases. Among the screened inhibitors, the HIV-1 protease inhibitors and KNI compounds have higher binding affinities for PfPMV with saquinavir having the highest value. The presence of a flexible group at P2 and a bulky hydrophobic group at P3 position of the inhibitor is preferred in the PfPMV substrate binding pocket. Results from the present study will aid in the design of potent inhibitors of PMV. PMID:27531685

  7. Integrate knowledge acquisition with target recognition through closed-loop ATR

    NASA Astrophysics Data System (ADS)

    Yu, Ssu-Hsin; McLaughlin, Pat; Zatezalo, Aleksandar; Hsiao, Kai-yuh; Boskovic, Jovan

    2015-05-01

    Automatic Target Recognition (ATR) algorithm performance is highly dependent on the sensing conditions under which the input data is collected. Open-loop fly-bys often produce poor results due to less than ideal measurement conditions. In addition, ATR algorithms must be extremely complicated to handle the diverse range of inputs with a resulting reduction in overall performance and increase in complexity. Our approach, closed-loop ATR (CL-ATR), focuses on improving the quality of information input to the ATR algorithms by optimizing motion, sensor settings and team (vehicle-vehicle-human) collaboration to dramatically improve classification accuracy. By managing the data collection guided by predicted ATR performance gain, we increase the information content of the data and thus dramatically improve ATR performance with existing ATR algorithms. CL-ATR has two major functions; first, an ATR utility function, which represents the performance sensitivity of ATR produced classification labels as a function of parameters that correlate to vehicle/sensor states. This utility function is developed off-line and is often available from the original ATR study as a confusion matrix, or it can be derived through simulation without direct access to the inner working of the ATR algorithm. The utility function is inserted into our CLATR framework to autonomously control the vehicle/sensor. Second, an on-board planner maps the utility function into vehicle position and sensor collection plans. Because we only require the utility function on-board, we can activate any ATR algorithm onto a unmanned aerial vehicle (UAV) platform no matter how complex. This pairing of ATR performance profiles with vehicle/sensor controls creates a unique and powerful active perception behavior.

  8. Human Exportin-1 is a Target for Combined Therapy of HIV and AIDS Related Lymphoma

    PubMed Central

    Boons, Eline; Vanstreels, Els; Jacquemyn, Maarten; Nogueira, Tatiane C.; Neggers, Jasper E.; Vercruysse, Thomas; van den Oord, Joost; Tamir, Sharon; Shacham, Sharon; Landesman, Yosef; Snoeck, Robert; Pannecouque, Christophe; Andrei, Graciela; Daelemans, Dirk

    2015-01-01

    Infection with HIV ultimately leads to advanced immunodeficiency resulting in an increased incidence of cancer. For example primary effusion lymphoma (PEL) is an aggressive non-Hodgkin lymphoma with very poor prognosis that typically affects HIV infected individuals in advanced stages of immunodeficiency. Here we report on the dual anti-HIV and anti-PEL effect of targeting a single process common in both diseases. Inhibition of the exportin-1 (XPO1) mediated nuclear transport by clinical stage orally bioavailable small molecule inhibitors (SINE) prevented the nuclear export of the late intron-containing HIV RNA species and consequently potently suppressed viral replication. In contrast, in CRISPR-Cas9 genome edited cells expressing mutant C528S XPO1, viral replication was unaffected upon treatment, clearly demonstrating the anti-XPO1 mechanism of action. At the same time, SINE caused the nuclear accumulation of p53 tumor suppressor protein as well as inhibition of NF-κB activity in PEL cells resulting in cell cycle arrest and effective apoptosis induction. In vivo, oral administration arrested PEL tumor growth in engrafted mice. Our findings provide strong rationale for inhibiting XPO1 as an innovative strategy for the combined anti-retroviral and anti-neoplastic treatment of HIV and PEL and offer perspectives for the treatment of other AIDS-associated cancers and potentially other virus-related malignancies. PMID:26501108

  9. Using a targeting metric to predict the utility of an EO imager as a pilotage aid

    NASA Astrophysics Data System (ADS)

    Vollmerhausen, Richard H.; Bui, Trang

    2006-05-01

    Army aviators use both image intensified goggles and thermal imagers as night vision aids when flying helicopters at night. The Targeting Task Performance (TTP) metric can be used to predict how well these imagers support the pilotage task under different illumination and thermal contrast conditions. The TTP metric predicts the field performance of the Aviator's Night Vision Imaging System, the Apache Helicopter Pilot's Night Vision System, and the Advanced Helicopter Pilotage system. These three systems represent diverse technologies: image intensified goggles, a first generation thermal imager, and a second-generation thermal imager. The ability of the TTP metric to predict the behavior of these diverse systems is evidence of its suitability as a pilotage metric. This paper discusses the application of the TTP metric to helicopter pilotage. Data from field surveys of Army aviators are used to validate the use of the TTP metric to predict pilotage system performance. Since knowledge of scene contrast is necessary to make sensor design trades using the TTP metric, a discussion of the terrain thermal contrast available in the mid-wave and long-wave infrared is also provided.

  10. Human Exportin-1 is a Target for Combined Therapy of HIV and AIDS Related Lymphoma.

    PubMed

    Boons, Eline; Vanstreels, Els; Jacquemyn, Maarten; Nogueira, Tatiane C; Neggers, Jasper E; Vercruysse, Thomas; van den Oord, Joost; Tamir, Sharon; Shacham, Sharon; Landesman, Yosef; Snoeck, Robert; Pannecouque, Christophe; Andrei, Graciela; Daelemans, Dirk

    2015-09-01

    Infection with HIV ultimately leads to advanced immunodeficiency resulting in an increased incidence of cancer. For example primary effusion lymphoma (PEL) is an aggressive non-Hodgkin lymphoma with very poor prognosis that typically affects HIV infected individuals in advanced stages of immunodeficiency. Here we report on the dual anti-HIV and anti-PEL effect of targeting a single process common in both diseases. Inhibition of the exportin-1 (XPO1) mediated nuclear transport by clinical stage orally bioavailable small molecule inhibitors (SINE) prevented the nuclear export of the late intron-containing HIV RNA species and consequently potently suppressed viral replication. In contrast, in CRISPR-Cas9 genome edited cells expressing mutant C528S XPO1, viral replication was unaffected upon treatment, clearly demonstrating the anti-XPO1 mechanism of action. At the same time, SINE caused the nuclear accumulation of p53 tumor suppressor protein as well as inhibition of NF-κB activity in PEL cells resulting in cell cycle arrest and effective apoptosis induction. In vivo, oral administration arrested PEL tumor growth in engrafted mice. Our findings provide strong rationale for inhibiting XPO1 as an innovative strategy for the combined anti-retroviral and anti-neoplastic treatment of HIV and PEL and offer perspectives for the treatment of other AIDS-associated cancers and potentially other virus-related malignancies.

  11. Computer aided screening of natural compounds targeting the E6 protein of HPV using molecular docking

    PubMed Central

    Mamgain, Saril; Sharma, Pushpendra; Pathak, Rajesh Kumar; Baunthiyal, Mamta

    2015-01-01

    The cancer profile in the Indian state of Uttarakhand reveals that the breast cancer is the most prevalent type of cancers in females followed by cervical and ovarian type. Literature survey shows that the E6 protein of Human Papilloma Virus-16 (HPV-16) is responsible for causing several forms of cancer in human. Therefore, it is of interest to screen HPV-16 E6 target protein with known natural compounds using computer aided molecular modeling and docking tools. The complete structure of E6 is unknown. Hence, the E6 structure model was constructed using different online servers followed by molecular docking of Colchine, Curcumin, Daphnoretin, Ellipticine and Epigallocatechin-3-gallate; five known natural compounds with best E6 protein model predicted by Phyre2 server. The screening exercise shows that Daphnoretin (with binding free energy of -8.3 kcal/mol), a natural compound derived from Wikstroemia indica has the top binding properties. Thus, it is of interest to consider the compound for further validation. PMID:26124567

  12. Using artificial bat sonar neural networks for complex pattern recognition: recognizing faces and the speed of a moving target.

    PubMed

    Dror, I E; Florer, F L; Rios, D; Zagaeski, M

    1996-04-01

    Two sets of studies examined the viability of using bat-like sonar input for artificial neural networks in complex pattern recognition tasks. In the first set of studies, a sonar neural network was required to perform two face recognition tasks. In the first task, the network was trained to recognize different faces regardless of facial expressions. Following training, the network was tested on its ability to generalize and correctly recognize faces using echoes of novel facial expressions that were not included in the training set. The neural network was able to recognize novel echoes of faces almost perfectly (above 96% accuracy) when it was required to recognize up to five faces. In the second face recognition task, a sonar neural network was trained to recognize the sex of 16 faces (eight males and eight females). After training, the network was able to correctly recognize novel echoes of those faces as 'male' or as 'female' faces with accuracy levels of 88%. However, the network was not able to recognize novel faces as 'male' or 'female' faces. In the second set of studies, a sonar neural network was required to learn to recognize the speed of a target that was moving towards the viewer. During training, the target was presented in a variety of orientations, and the network's performance was evaluated when the target was presented in novel orientations that were not included in the training set. The different orientations dramatically affected the amplitude and the frequency composition of the echoes. The neural network was able to learn and recognize the speed of a moving target, and to generalize to new orientations of the target. However, the network was not able to generalize to new speeds that were not included in the training set. The potential and limitations of using bat-like sonar as input for artifical neural networks are discussed.

  13. Complexity and Targeting in Federal Student Aid: A Quantitative Analysis. NBER Working Paper No. 13801

    ERIC Educational Resources Information Center

    Dynarski, Susan; Scott-Clayton, Judith E.

    2008-01-01

    A growing body of empirical evidence shows that some financial aid programs increase college enrollment. Puzzlingly, there is little compelling evidence that Pell Grants and Stafford Loans, the primary federal student aid programs, are effective in achieving this goal. In this paper, we provide an in-depth review of this evidence, which taken as a…

  14. Increase in Speech Recognition due to Linguistic Mismatch Between Target and Masker Speech: Monolingual and Simultaneous Bilingual Performance

    PubMed Central

    Calandruccio, Lauren; Zhou, Haibo

    2014-01-01

    Purpose To examine whether improved speech recognition during linguistically mismatched target–masker experiments is due to linguistic unfamiliarity of the masker speech or linguistic dissimilarity between the target and masker speech. Method Monolingual English speakers (n = 20) and English–Greek simultaneous bilinguals (n = 20) listened to English sentences in the presence of competing English and Greek speech. Data were analyzed using mixed-effects regression models to determine differences in English recogition performance between the 2 groups and 2 masker conditions. Results Results indicated that English sentence recognition for monolinguals and simultaneous English–Greek bilinguals improved when the masker speech changed from competing English to competing Greek speech. Conclusion The improvement in speech recognition that has been observed for linguistically mismatched target–masker experiments cannot be simply explained by the masker language being linguistically unknown or unfamiliar to the listeners. Listeners can improve their speech recognition in linguistically mismatched target–masker experiments even when the listener is able to obtain meaningful linguistic information from the masker speech. PMID:24167230

  15. FERM-dependent E3 ligase recognition is a conserved mechanism for targeted degradation of lipoprotein receptors.

    PubMed

    Calkin, Anna C; Goult, Benjamin T; Zhang, Li; Fairall, Louise; Hong, Cynthia; Schwabe, John W R; Tontonoz, Peter

    2011-12-13

    The E3 ubiquitin ligase IDOL (inducible degrader of the LDL receptor) regulates LDL receptor (LDLR)-dependent cholesterol uptake, but its mechanism of action, including the molecular basis for its stringent specificity, is poorly understood. Here we show that IDOL uses a singular strategy among E3 ligases for target recognition. The IDOL FERM domain binds directly to a recognition sequence in the cytoplasmic tails of lipoprotein receptors. This physical interaction is independent of IDOL's really interesting new gene (RING) domain E3 ligase activity and its capacity for autoubiquitination. Furthermore, IDOL controls its own stability through autoubiquitination of a unique FERM subdomain fold not present in other FERM proteins. Key residues defining the IDOL-LDLR interaction and IDOL autoubiquitination are functionally conserved in their insect homologs. Finally, we demonstrate that target recognition by IDOL involves a tripartite interaction between the FERM domain, membrane phospholipids, and the lipoprotein receptor tail. Our data identify the IDOL-LDLR interaction as an evolutionarily conserved mechanism for the regulation of lipid uptake and suggest that this interaction could potentially be exploited for the pharmacologic modulation of lipid metabolism.

  16. FERM-dependent E3 ligase recognition is a conserved mechanism for targeted degradation of lipoprotein receptors

    PubMed Central

    Calkin, Anna C.; Goult, Benjamin T.; Zhang, Li; Fairall, Louise; Hong, Cynthia; Schwabe, John W. R.; Tontonoz, Peter

    2011-01-01

    The E3 ubiquitin ligase IDOL (inducible degrader of the LDL receptor) regulates LDL receptor (LDLR)-dependent cholesterol uptake, but its mechanism of action, including the molecular basis for its stringent specificity, is poorly understood. Here we show that IDOL uses a singular strategy among E3 ligases for target recognition. The IDOL FERM domain binds directly to a recognition sequence in the cytoplasmic tails of lipoprotein receptors. This physical interaction is independent of IDOL's really interesting new gene (RING) domain E3 ligase activity and its capacity for autoubiquitination. Furthermore, IDOL controls its own stability through autoubiquitination of a unique FERM subdomain fold not present in other FERM proteins. Key residues defining the IDOL–LDLR interaction and IDOL autoubiquitination are functionally conserved in their insect homologs. Finally, we demonstrate that target recognition by IDOL involves a tripartite interaction between the FERM domain, membrane phospholipids, and the lipoprotein receptor tail. Our data identify the IDOL–LDLR interaction as an evolutionarily conserved mechanism for the regulation of lipid uptake and suggest that this interaction could potentially be exploited for the pharmacologic modulation of lipid metabolism. PMID:22109552

  17. Target Achievement Control Test: evaluating real-time myoelectric pattern-recognition control of multifunctional upper-limb prostheses.

    PubMed

    Simon, Ann M; Hargrove, Levi J; Lock, Blair A; Kuiken, Todd A

    2011-01-01

    Despite high classification accuracies (~95%) of myoelectric control systems based on pattern recognition, how well offline measures translate to real-time closed-loop control is unclear. Recently, a real-time virtual test analyzed how well subjects completed arm motions using a multiple-degree of freedom (DOF) classifier. Although this test provided real-time performance metrics, the required task was oversimplified: motion speeds were normalized and unintended movements were ignored. We included these considerations in a new, more challenging virtual test called the Target Achievement Control Test (TAC Test). Five subjects with transradial amputation attempted to move a virtual arm into a target posture using myoelectric pattern recognition, performing the test with various classifier (1- vs 3-DOF) and task complexities (one vs three required motions per posture). We found no significant difference in classification accuracy between the 1- and 3-DOF classifiers (97.2% +/- 2.0% and 94.1% +/- 3.1%, respectively; p = 0.14). Subjects completed 31% fewer trials in significantly more time using the 3-DOF classifier and took 3.6 +/- 0.8 times longer to reach a three-motion posture compared with a one-motion posture. These results highlight the need for closed-loop performance measures and demonstrate that the TAC Test is a useful and more challenging tool to test real-time pattern-recognition performance.

  18. Orthodenticle Is Required for the Expression of Principal Recognition Molecules That Control Axon Targeting in the Drosophila Retina.

    PubMed

    Mencarelli, Chiara; Pichaud, Franck

    2015-06-01

    Parallel processing of neuronal inputs relies on assembling neural circuits into distinct synaptic-columns and layers. This is orchestrated by matching recognition molecules between afferent growth cones and target areas. Controlling the expression of these molecules during development is crucial but not well understood. The developing Drosophila visual system is a powerful genetic model for addressing this question. In this model system, the achromatic R1-6 photoreceptors project their axons in the lamina while the R7 and R8 photoreceptors, which are involved in colour detection, project their axons to two distinct synaptic-layers in the medulla. Here we show that the conserved homeodomain transcription factor Orthodenticle (Otd), which in the eye is a main regulator of rhodopsin expression, is also required for R1-6 photoreceptor synaptic-column specific innervation of the lamina. Our data indicate that otd function in these photoreceptors is largely mediated by the recognition molecules flamingo (fmi) and golden goal (gogo). In addition, we find that otd regulates synaptic-layer targeting of R8. We demonstrate that during this process, otd and the R8-specific transcription factor senseless/Gfi1 (sens) function as independent transcriptional inputs that are required for the expression of fmi, gogo and the adhesion molecule capricious (caps), which govern R8 synaptic-layer targeting. Our work therefore demonstrates that otd is a main component of the gene regulatory network that regulates synaptic-column and layer targeting in the fly visual system. PMID:26114289

  19. Colorimetric and fluorogenic recognition of Hg2+ and Cr3+ in acetonitrile and their test paper recognition in aqueous media with the aid of rhodamine based sensors.

    PubMed

    Patidar, Rajesh; Rebary, Babulal; Paul, Parimal

    2015-03-01

    Two new rhodamine derivatives (L1 and L2) were synthesized, characterized and their ion recognition property has been investigated. Both of the ionophores exhibit colorimetric and fluorogenic response for Hg(2+) and Cr(3+) ions among large number of alkali, alkaline earth and transition metal ions tested in acetonitrile. Detail studies on determination of binding constant, binding mode, reversibility of binding, lower detection limit have been carried out. Detection of metal ions in aqueous media has also been demonstrated by preparation of simple, convenient and disposable test paper sensors with two approaches viz. filter paper and membrane filter loaded with these ionophores. Both of these methods responded sharply to both the metal ions (Hg(2+) and Cr(3+)) in aqueous solution, detectable by bared-eye. For better sensing at low concentration of metal ions, reprecipitation followed by filtration enrichment of ligands on membrane filter was employed. PMID:25666715

  20. A Tumor-specific MicroRNA Recognition System Facilitates the Accurate Targeting to Tumor Cells by Magnetic Nanoparticles

    PubMed Central

    Yu, Yingting; Yao, Yi; Yan, Hao; Wang, Rui; Zhang, Zhenming; Sun, Xiaodan; Zhao, Lingyun; Ao, Xiang; Xie, Zhen; Wu, Qiong

    2016-01-01

    Targeted therapy for cancer is a research area of great interest, and magnetic nanoparticles (MNPs) show great potential as targeted carriers for therapeutics. One important class of cancer biomarkers is microRNAs (miRNAs), which play a significant role in tumor initiation and progression. In this study, a cascade recognition system containing multiple plasmids, including a Tet activator, a lacI repressor gene driven by the TetOn promoter, and a reporter gene repressed by the lacI repressor and influenced by multiple endogenous miRNAs, was used to recognize cells that display miRNA signals that are characteristic of cancer. For this purpose, three types of signal miRNAs with high proliferation and metastasis abilities were chosen (miR-21, miR-145, and miR-9). The response of this system to the human breast cancer MCF-7 cell line was 3.2-fold higher than that to the human breast epithelial HBL100 cell line and almost 7.5-fold higher than that to human embryonic kidney HEK293T cells. In combination with polyethyleneimine-modified MNPs, this recognition system targeted the tumor location in situ in an animal model, and an ~42% repression of tumor growth was achieved. Our study provides a new combination of magnetic nanocarrier and gene therapy based on miRNAs that are active in vivo, which has potential for use in future cancer therapies. PMID:27138178

  1. Computer-Aided Targeting of the PI3K/Akt/mTOR Pathway: Toxicity Reduction and Therapeutic Opportunities

    PubMed Central

    Li, Tan; Wang, Guanyu

    2014-01-01

    The PI3K/Akt/mTOR pathway plays an essential role in a wide range of biological functions, including metabolism, macromolecular synthesis, cell growth, proliferation and survival. Its versatility, however, makes it a conspicuous target of many pathogens; and the consequential deregulations of this pathway often lead to complications, such as tumorigenesis, type 2 diabetes and cardiovascular diseases. Molecular targeted therapy, aimed at modulating the deregulated pathway, holds great promise for controlling these diseases, though side effects may be inevitable, given the ubiquity of the pathway in cell functions. Here, we review a variety of factors found to modulate the PI3K/Akt/mTOR pathway, including gene mutations, certain metabolites, inflammatory factors, chemical toxicants, drugs found to rectify the pathway, as well as viruses that hijack the pathway for their own synthetic purposes. Furthermore, this evidence of PI3K/Akt/mTOR pathway alteration and related pathogenesis has inspired the exploration of computer-aided targeting of this pathway to optimize therapeutic strategies. Herein, we discuss several possible options, using computer-aided targeting, to reduce the toxicity of molecularly-targeted therapy, including mathematical modeling, to reveal system-level control mechanisms and to confer a low-dosage combination therapy, the potential of PP2A as a therapeutic target, the formulation of parameters to identify patients who would most benefit from specific targeted therapies and molecular dynamics simulations and docking studies to discover drugs that are isoform specific or mutation selective so as to avoid undesired broad inhibitions. We hope this review will stimulate novel ideas for pharmaceutical discovery and deepen our understanding of curability and toxicity by targeting the PI3K/Akt/mTOR pathway. PMID:25334061

  2. EduSpeak[R]: A Speech Recognition and Pronunciation Scoring Toolkit for Computer-Aided Language Learning Applications

    ERIC Educational Resources Information Center

    Franco, Horacio; Bratt, Harry; Rossier, Romain; Rao Gadde, Venkata; Shriberg, Elizabeth; Abrash, Victor; Precoda, Kristin

    2010-01-01

    SRI International's EduSpeak[R] system is a software development toolkit that enables developers of interactive language education software to use state-of-the-art speech recognition and pronunciation scoring technology. Automatic pronunciation scoring allows the computer to provide feedback on the overall quality of pronunciation and to point to…

  3. Interstitial branch formation within the red nucleus by deep cerebellar nuclei-derived commissural axons during target recognition.

    PubMed

    Hara, Satoshi; Kaneyama, Takeshi; Inamata, Yasuyuki; Onodera, Ryota; Shirasaki, Ryuichi

    2016-04-01

    Target recognition by developing axons is one of the fundamental steps for establishing the proper pattern of neuronal connectivity during development. However, knowledge of the mechanisms that underlie this critical event is still limited. In this study, to examine how commissural axons in vertebrates recognize their targets after crossing the midline, we analyzed in detail the behavior of postcrossing commissural axons derived from the deep cerebellar nuclei (DCN) in the developing mouse cerebellum. For this, we employed a cell-type-specific genetic labeling approach to selectively visualize DCN axons during the time when these axons project to the red nucleus (RN), one of the well-characterized targets of DCN axons. We found that, when DCN axons initially entered the RN at its caudal end, these axons continued to grow rostrally through the RN without showing noticeable morphological signs of axon branching. Interestingly, after a delay, DCN axons started forming interstitial branches from the portion of the axon shaft selectively within the RN. Because commissural axons acquire responsiveness to several guidance cues when they cross the midline, we further addressed whether midline crossing is a prerequisite for subsequent targeting by using a Robo3 knockdown strategy. We found that DCN axons were still capable of forming interstitial branches within the RN even in the absence of midline crossing. These results therefore suggest that the mechanism of RN recognition by DCN axons involves a delayed interstitial branching, and that these axons possess an intrinsic ability to respond to the target-derived cues irrespective of midline crossing.

  4. Targeting HIV reverse transcriptase for anti-AIDS drug design: structural and biological considerations for chemotherapeutic strategies.

    PubMed

    Arnold, E; Das, K; Ding, J; Yadav, P N; Hsiou, Y; Boyer, P L; Hughes, S H

    1996-04-01

    The reverse transcriptase of HIV is a key target for the antiviral treatment of AIDS. Numerous potent inhibitors of RT have been described including all of the drugs that have been currently licensed for the treatment of AIDS, but their efficacy has been limited by the emergence of drug-resistant HIV variants. Extensive biochemical, genetic, and clinical data about HIV RT enzymatic mechanisms, inhibition, and drug resistance have been reported. This information, taken together with structural data from crystallographic studies of HIV-1 RT, has set the stage for structure-based design of improved inhibitors of this essential viral enzyme. Comparisons of the different crystal structures of HIV-1 RT shows that the enzyme has great conformational flexibility, providing additional possibilities for drug targeting. Recent clinical and virological data suggest that HIV-1 RT enzymes that carry drug-resistance mutations can be substantially impaired and that combinations of RT inhibitors can produce significant clinical benefit in the treatment of AIDS. An immediate goal is to use the available information to design specific inhibitors or combination therapies that will select for relatively less fit HIV variants.

  5. Road-Aided Ground Slowly Moving Target 2D Motion Estimation for Single-Channel Synthetic Aperture Radar.

    PubMed

    Wang, Zhirui; Xu, Jia; Huang, Zuzhen; Zhang, Xudong; Xia, Xiang-Gen; Long, Teng; Bao, Qian

    2016-03-16

    To detect and estimate ground slowly moving targets in airborne single-channel synthetic aperture radar (SAR), a road-aided ground moving target indication (GMTI) algorithm is proposed in this paper. First, the road area is extracted from a focused SAR image based on radar vision. Second, after stationary clutter suppression in the range-Doppler domain, a moving target is detected and located in the image domain via the watershed method. The target's position on the road as well as its radial velocity can be determined according to the target's offset distance and traffic rules. Furthermore, the target's azimuth velocity is estimated based on the road slope obtained via polynomial fitting. Compared with the traditional algorithms, the proposed method can effectively cope with slowly moving targets partly submerged in a stationary clutter spectrum. In addition, the proposed method can be easily extended to a multi-channel system to further improve the performance of clutter suppression and motion estimation. Finally, the results of numerical experiments are provided to demonstrate the effectiveness of the proposed algorithm.

  6. Road-Aided Ground Slowly Moving Target 2D Motion Estimation for Single-Channel Synthetic Aperture Radar.

    PubMed

    Wang, Zhirui; Xu, Jia; Huang, Zuzhen; Zhang, Xudong; Xia, Xiang-Gen; Long, Teng; Bao, Qian

    2016-01-01

    To detect and estimate ground slowly moving targets in airborne single-channel synthetic aperture radar (SAR), a road-aided ground moving target indication (GMTI) algorithm is proposed in this paper. First, the road area is extracted from a focused SAR image based on radar vision. Second, after stationary clutter suppression in the range-Doppler domain, a moving target is detected and located in the image domain via the watershed method. The target's position on the road as well as its radial velocity can be determined according to the target's offset distance and traffic rules. Furthermore, the target's azimuth velocity is estimated based on the road slope obtained via polynomial fitting. Compared with the traditional algorithms, the proposed method can effectively cope with slowly moving targets partly submerged in a stationary clutter spectrum. In addition, the proposed method can be easily extended to a multi-channel system to further improve the performance of clutter suppression and motion estimation. Finally, the results of numerical experiments are provided to demonstrate the effectiveness of the proposed algorithm. PMID:26999140

  7. Interaction of periodate-oxidized target cells and cytolytic T lymphocytes: a model system of "polyclonal MHC recognition".

    PubMed

    Keren, Z; Berke, G

    1986-09-01

    In oxidation-dependent cytotoxicity (ODCC), cytolytic T lymphocytes (CTL) non-specifically recognize, bind to and lyse oxidized target cells (O-TC) but the precise mechanism whereby CTL react with O-TC is far from clear (Berke, G., Immunol. Rev. 1983. 72:5). Here we present evidence that CTL/O-TC interactions are blocked by aldehyde-reactive reagents such as hydroxylamine, adipic acid dihydrazide and thiocarbohydrazide and that preformed CTL/O-TC conjugates dissociate upon reduction with NaBH4, suggesting that active aldehyde groups of O-TC rather than intercellular Schiff bases are involved in the recognition and lysis of O-TC by CTL in ODCC. The aldehydes are bound to trypsin-sensitive, non-H-2 glycoproteins that appear to be different and unique in the three different target cell lines so far examined (EL4, L1210, R1.1). In view of these and previous findings we would like to suggest that in ODCC, active aldehydes react with adjacent major histocompatibility complex and perhaps other cell-surface molecules to create a multitude of modified conformations, responsible for the "polyclonal" (nonspecific) MHC recognition and lysis of O-TC by CTL, as well as for an altered pattern of H-2 antibody binding to O-TC. PMID:3019706

  8. Scarcity of HIV-AIDS Risk-Reduction Materials Targeting the Needs of Older Adults among State Departments of Public Health

    ERIC Educational Resources Information Center

    Orel, Nancy A.; Wright, Jeanne M.; Wagner, Jennifer

    2004-01-01

    This study investigated the availability of printed human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) education/prevention materials from state departments of public health within the United States, which specifically targeted the older adult population. Information on HIV/AIDS from public health departments in each of…

  9. Evaluation of a targeted AIDS prevention intervention to increase condom use among prostitutes in Ghana.

    PubMed

    Asamoah-Adu, A; Weir, S; Pappoe, M; Kanlisi, N; Neequaye, A; Lamptey, P

    1994-02-01

    Findings of a prospective study of condom use among prostitutes in Ghana provided support for acquired immunodeficiency syndrome (AIDS) prevention educational interventions with this high risk populating and evidence of informal program diffusion. 382 self-identified prostitutes voluntarily entered the study in three waves (a pilot group of 72 recruited in June 1987, another 176 prostitutes who were admitted at their request in January 1988, and 106 who entered in September 1991). From this group, selected prostitutes were trained to educate their peers about AIDS risk factors through meetings and printed materials and to distribute free condoms. Self-reported condom use in 1991 was correlated with contact with these peer educators. During the 6-month pilot study, the proportion of prostitutes who always used condom increased from 6% at baseline to 71%. 48% of prostitutes entering the study in January 1988 were already always using condoms, suggesting a diffusion effect. In 1991, consistent condom use was reported by 56% of women from the pilot group available for follow-up and 66% of those interviewed from the 1988 wave; however, these rates were not appreciably higher than the 55% rate reported at baseline by the 1991 wave of recruits. (This convergence is assumed to reflect both suspension of the educational program in 1988-91 and increased social acceptance of condom use given the spread of AIDS.) Of the 107 women from the pilot and expanded groups available for interview in 1991, 24% identified peer outreach workers as their source of AIDS information. Women who had contact with staff were 2.63 times more likely than non-exposed women to report consistent condom use. The interaction model revealed that women who maintained contact with project staff were 3.17 times more likely to be consistent users, those who knew that healthy appearing men could transmit AIDS were 2.68 times more likely to fall into this use category, and prostitutes who had clients who

  10. Multi-source feature extraction and target recognition in wireless sensor networks based on adaptive distributed wavelet compression algorithms

    NASA Astrophysics Data System (ADS)

    Hortos, William S.

    2008-04-01

    Proposed distributed wavelet-based algorithms are a means to compress sensor data received at the nodes forming a wireless sensor network (WSN) by exchanging information between neighboring sensor nodes. Local collaboration among nodes compacts the measurements, yielding a reduced fused set with equivalent information at far fewer nodes. Nodes may be equipped with multiple sensor types, each capable of sensing distinct phenomena: thermal, humidity, chemical, voltage, or image signals with low or no frequency content as well as audio, seismic or video signals within defined frequency ranges. Compression of the multi-source data through wavelet-based methods, distributed at active nodes, reduces downstream processing and storage requirements along the paths to sink nodes; it also enables noise suppression and more energy-efficient query routing within the WSN. Targets are first detected by the multiple sensors; then wavelet compression and data fusion are applied to the target returns, followed by feature extraction from the reduced data; feature data are input to target recognition/classification routines; targets are tracked during their sojourns through the area monitored by the WSN. Algorithms to perform these tasks are implemented in a distributed manner, based on a partition of the WSN into clusters of nodes. In this work, a scheme of collaborative processing is applied for hierarchical data aggregation and decorrelation, based on the sensor data itself and any redundant information, enabled by a distributed, in-cluster wavelet transform with lifting that allows multiple levels of resolution. The wavelet-based compression algorithm significantly decreases RF bandwidth and other resource use in target processing tasks. Following wavelet compression, features are extracted. The objective of feature extraction is to maximize the probabilities of correct target classification based on multi-source sensor measurements, while minimizing the resource expenditures at

  11. Cardiac-Oxidized Antigens Are Targets of Immune Recognition by Antibodies and Potential Molecular Determinants in Chagas Disease Pathogenesis

    PubMed Central

    Dhiman, Monisha; Zago, Maria Paola; Nunez, Sonia; Amoroso, Alejandro; Rementeria, Hugo; Dousset, Pierre; Burgos, Federico Nunez; Garg, Nisha Jain

    2012-01-01

    Trypanosoma cruzi elicits reactive oxygen species (ROS) of inflammatory and mitochondrial origin in infected hosts. In this study, we examined ROS-induced oxidative modifications in the heart and determined whether the resultant oxidized cardiac proteins are targets of immune response and of pathological significance in Chagas disease. Heart biopsies from chagasic mice, rats and human patients exhibited, when compared to those from normal controls, a substantial increase in protein 4-hydroxynonenal (4-HNE), malondialdehyde (MDA), carbonyl, and 3-nitrotyrosine (3-NT) adducts. To evaluate whether oxidized proteins gain antigenic properties, heart homogenates or isolated cardiomyocytes were oxidized in vitro and one- or two-dimensional gel electrophoresis (2D-GE)/Western blotting (WB) was performed to investigate the proteomic oxidative changes and recognition of oxidized proteins by sera antibodies in chagasic rodents (mice, rats) and human patients. Human cardiomyocytes exhibited LD50 sensitivity to 30 µM 4-HNE and 100 µM H2O2 at 6 h and 12 h, respectively. In vitro oxidation with 4-HNE or H2O2 resulted in a substantial increase in 4-HNE- and carbonyl-modified proteins that correlated with increased recognition of cardiac (cardiomyocytes) proteins by sera antibodies of chagasic rodents and human patients. 2D-GE/Western blotting followed by MALDI-TOF-MS/MS analysis to identify cardiac proteins that were oxidized and recognized by human chagasic sera yielded 82 unique proteins. We validated the 2D-GE results by enzyme-linked immunosorbent assay (ELISA) and WB and demonstrated that oxidation of recombinant titin enhanced its immunogenicity and recognition by sera antibodies from chagasic hosts (rats and humans). Treatment of infected rats with phenyl-α-tert-butyl nitrone (PBN, antioxidant) resulted in normalized immune detection of cardiac proteins associated with control of cardiac pathology and preservation of heart contractile function in chagasic rats. We

  12. Recognition of a Functional Peroxisome Type 1 Target by the Dynamic Import Receptor Pex5p

    PubMed Central

    Stanley, Will A.; Filipp, Fabian V.; Kursula, Petri; Schüller, Nicole; Erdmann, Ralf; Schliebs, Wolfgang; Sattler, Michael; Wilmanns, Matthias

    2016-01-01

    Summary Peroxisomes require the translocation of folded and functional target proteins of various sizes across the peroxisomal membrane. We have investigated the structure and function of the principal import receptor Pex5p, which recognizes targets bearing a C-terminal peroxisomal targeting signal type 1. Crystal structures of the receptor in the presence and absence of a peroxisomal target, sterol carrier protein 2, reveal major structural changes from an open, snail-like conformation into a closed, circular conformation. These changes are caused by a long loop C terminal to the 7-fold tetratricopeptide repeat segments. Mutations in residues of this loop lead to defects in peroxisomal import in human fibroblasts. The structure of the receptor/cargo complex demonstrates that the primary receptor-binding site of the cargo is structurally and topologically autonomous, enabling the cargo to retain its native structure and function. PMID:17157249

  13. Tracking and Recognition of Multiple Human Targets Moving in a Wireless Pyroelectric Infrared Sensor Network

    PubMed Central

    Xiong, Ji; Li, Fangmin; Zhao, Ning; Jiang, Na

    2014-01-01

    With characteristics of low-cost and easy deployment, the distributed wireless pyroelectric infrared sensor network has attracted extensive interest, which aims to make it an alternate infrared video sensor in thermal biometric applications for tracking and identifying human targets. In these applications, effectively processing signals collected from sensors and extracting the features of different human targets has become crucial. This paper proposes the application of empirical mode decomposition and the Hilbert-Huang transform to extract features of moving human targets both in the time domain and the frequency domain. Moreover, the support vector machine is selected as the classifier. The experimental results demonstrate that by using this method the identification rates of multiple moving human targets are around 90%. PMID:24759117

  14. Structural and sequencing analysis of local target DNA recognition by MLV integrase

    PubMed Central

    Aiyer, Sriram; Rossi, Paolo; Malani, Nirav; Schneider, William M.; Chandar, Ashwin; Bushman, Frederic D.; Montelione, Gaetano T.; Roth, Monica J.

    2015-01-01

    Target-site selection by retroviral integrase (IN) proteins profoundly affects viral pathogenesis. We describe the solution nuclear magnetic resonance structure of the Moloney murine leukemia virus IN (M-MLV) C-terminal domain (CTD) and a structural homology model of the catalytic core domain (CCD). In solution, the isolated MLV IN CTD adopts an SH3 domain fold flanked by a C-terminal unstructured tail. We generated a concordant MLV IN CCD structural model using SWISS-MODEL, MMM-tree and I-TASSER. Using the X-ray crystal structure of the prototype foamy virus IN target capture complex together with our MLV domain structures, residues within the CCD α2 helical region and the CTD β1-β2 loop were predicted to bind target DNA. The role of these residues was analyzed in vivo through point mutants and motif interchanges. Viable viruses with substitutions at the IN CCD α2 helical region and the CTD β1-β2 loop were tested for effects on integration target site selection. Next-generation sequencing and analysis of integration target sequences indicate that the CCD α2 helical region, in particular P187, interacts with the sequences distal to the scissile bonds whereas the CTD β1-β2 loop binds to residues proximal to it. These findings validate our structural model and disclose IN-DNA interactions relevant to target site selection. PMID:25969444

  15. Structural and sequencing analysis of local target DNA recognition by MLV integrase.

    PubMed

    Aiyer, Sriram; Rossi, Paolo; Malani, Nirav; Schneider, William M; Chandar, Ashwin; Bushman, Frederic D; Montelione, Gaetano T; Roth, Monica J

    2015-06-23

    Target-site selection by retroviral integrase (IN) proteins profoundly affects viral pathogenesis. We describe the solution nuclear magnetic resonance structure of the Moloney murine leukemia virus IN (M-MLV) C-terminal domain (CTD) and a structural homology model of the catalytic core domain (CCD). In solution, the isolated MLV IN CTD adopts an SH3 domain fold flanked by a C-terminal unstructured tail. We generated a concordant MLV IN CCD structural model using SWISS-MODEL, MMM-tree and I-TASSER. Using the X-ray crystal structure of the prototype foamy virus IN target capture complex together with our MLV domain structures, residues within the CCD α2 helical region and the CTD β1-β2 loop were predicted to bind target DNA. The role of these residues was analyzed in vivo through point mutants and motif interchanges. Viable viruses with substitutions at the IN CCD α2 helical region and the CTD β1-β2 loop were tested for effects on integration target site selection. Next-generation sequencing and analysis of integration target sequences indicate that the CCD α2 helical region, in particular P187, interacts with the sequences distal to the scissile bonds whereas the CTD β1-β2 loop binds to residues proximal to it. These findings validate our structural model and disclose IN-DNA interactions relevant to target site selection. PMID:25969444

  16. Mechanism of intermediate filament recognition by plakin repeat domains revealed by envoplakin targeting of vimentin

    PubMed Central

    Fogl, Claudia; Mohammed, Fiyaz; Al-Jassar, Caezar; Jeeves, Mark; Knowles, Timothy J.; Rodriguez-Zamora, Penelope; White, Scott A.; Odintsova, Elena; Overduin, Michael; Chidgey, Martyn

    2016-01-01

    Plakin proteins form critical connections between cell junctions and the cytoskeleton; their disruption within epithelial and cardiac muscle cells cause skin-blistering diseases and cardiomyopathies. Envoplakin has a single plakin repeat domain (PRD) which recognizes intermediate filaments through an unresolved mechanism. Herein we report the crystal structure of envoplakin's complete PRD fold, revealing binding determinants within its electropositive binding groove. Four of its five internal repeats recognize negatively charged patches within vimentin via five basic determinants that are identified by nuclear magnetic resonance spectroscopy. Mutations of the Lys1901 or Arg1914 binding determinants delocalize heterodimeric envoplakin from intracellular vimentin and keratin filaments in cultured cells. Recognition of vimentin is abolished when its residues Asp112 or Asp119 are mutated. The latter slot intermediate filament rods into basic PRD domain grooves through electrosteric complementarity in a widely applicable mechanism. Together this reveals how plakin family members form dynamic linkages with cytoskeletal frameworks. PMID:26935805

  17. Mechanism of intermediate filament recognition by plakin repeat domains revealed by envoplakin targeting of vimentin.

    PubMed

    Fogl, Claudia; Mohammed, Fiyaz; Al-Jassar, Caezar; Jeeves, Mark; Knowles, Timothy J; Rodriguez-Zamora, Penelope; White, Scott A; Odintsova, Elena; Overduin, Michael; Chidgey, Martyn

    2016-01-01

    Plakin proteins form critical connections between cell junctions and the cytoskeleton; their disruption within epithelial and cardiac muscle cells cause skin-blistering diseases and cardiomyopathies. Envoplakin has a single plakin repeat domain (PRD) which recognizes intermediate filaments through an unresolved mechanism. Herein we report the crystal structure of envoplakin's complete PRD fold, revealing binding determinants within its electropositive binding groove. Four of its five internal repeats recognize negatively charged patches within vimentin via five basic determinants that are identified by nuclear magnetic resonance spectroscopy. Mutations of the Lys1901 or Arg1914 binding determinants delocalize heterodimeric envoplakin from intracellular vimentin and keratin filaments in cultured cells. Recognition of vimentin is abolished when its residues Asp112 or Asp119 are mutated. The latter slot intermediate filament rods into basic PRD domain grooves through electrosteric complementarity in a widely applicable mechanism. Together this reveals how plakin family members form dynamic linkages with cytoskeletal frameworks. PMID:26935805

  18. Mechanism of intermediate filament recognition by plakin repeat domains revealed by envoplakin targeting of vimentin

    NASA Astrophysics Data System (ADS)

    Fogl, Claudia; Mohammed, Fiyaz; Al-Jassar, Caezar; Jeeves, Mark; Knowles, Timothy J.; Rodriguez-Zamora, Penelope; White, Scott A.; Odintsova, Elena; Overduin, Michael; Chidgey, Martyn

    2016-03-01

    Plakin proteins form critical connections between cell junctions and the cytoskeleton; their disruption within epithelial and cardiac muscle cells cause skin-blistering diseases and cardiomyopathies. Envoplakin has a single plakin repeat domain (PRD) which recognizes intermediate filaments through an unresolved mechanism. Herein we report the crystal structure of envoplakin's complete PRD fold, revealing binding determinants within its electropositive binding groove. Four of its five internal repeats recognize negatively charged patches within vimentin via five basic determinants that are identified by nuclear magnetic resonance spectroscopy. Mutations of the Lys1901 or Arg1914 binding determinants delocalize heterodimeric envoplakin from intracellular vimentin and keratin filaments in cultured cells. Recognition of vimentin is abolished when its residues Asp112 or Asp119 are mutated. The latter slot intermediate filament rods into basic PRD domain grooves through electrosteric complementarity in a widely applicable mechanism. Together this reveals how plakin family members form dynamic linkages with cytoskeletal frameworks.

  19. Mechanism of intermediate filament recognition by plakin repeat domains revealed by envoplakin targeting of vimentin.

    PubMed

    Fogl, Claudia; Mohammed, Fiyaz; Al-Jassar, Caezar; Jeeves, Mark; Knowles, Timothy J; Rodriguez-Zamora, Penelope; White, Scott A; Odintsova, Elena; Overduin, Michael; Chidgey, Martyn

    2016-01-01

    Plakin proteins form critical connections between cell junctions and the cytoskeleton; their disruption within epithelial and cardiac muscle cells cause skin-blistering diseases and cardiomyopathies. Envoplakin has a single plakin repeat domain (PRD) which recognizes intermediate filaments through an unresolved mechanism. Herein we report the crystal structure of envoplakin's complete PRD fold, revealing binding determinants within its electropositive binding groove. Four of its five internal repeats recognize negatively charged patches within vimentin via five basic determinants that are identified by nuclear magnetic resonance spectroscopy. Mutations of the Lys1901 or Arg1914 binding determinants delocalize heterodimeric envoplakin from intracellular vimentin and keratin filaments in cultured cells. Recognition of vimentin is abolished when its residues Asp112 or Asp119 are mutated. The latter slot intermediate filament rods into basic PRD domain grooves through electrosteric complementarity in a widely applicable mechanism. Together this reveals how plakin family members form dynamic linkages with cytoskeletal frameworks.

  20. Deconstructing the portrayals of HIV/AIDS among campaign planners targeting tribal populations in Koraput, India: a culture-centered interrogation.

    PubMed

    Acharya, Lalatendu; Dutta, Mohan Jyoti

    2012-01-01

    This article deconstructs the portrayal of HIV/AIDS in the tribal dominated district of Koraput, India, among program planners, service delivery personnel, nongovernmental organizations (NGOs), etc. who plan, implement, and evaluate HIV/AIDS interventions targeting tribal communities in the region. Drawing upon postcolonial and subaltern studies approaches, we critically examine the ideological assumptions that circulate in the dominant discursive spaces among campaign planners and implementers who target HIV/AIDS among the tribal population in Koraput, India. Based on our critical examination, we suggest guidelines for engaging with program planners and implementers through health communication pedagogy informed by the culture-centered approach. PMID:22128880

  1. Translational control and target recognition by Escherichia coli small RNAs in vivo

    PubMed Central

    Urban, Johannes H.; Vogel, Jörg

    2007-01-01

    Small non-coding RNAs (sRNAs) are an emerging class of regulators of bacterial gene expression. Most of the regulatory Escherichia coli sRNAs known to date modulate translation of trans-encoded target mRNAs. We studied the specificity of sRNA target interactions using gene fusions to green fluorescent protein (GFP) as a novel reporter of translational control by bacterial sRNAs in vivo. Target sequences were selected from both monocistronic and polycistronic mRNAs. Upon expression of the cognate sRNA (DsrA, GcvB, MicA, MicC, MicF, RprA, RyhB, SgrS and Spot42), we observed highly specific translation repression/activation of target fusions under various growth conditions. Target regulation was also tested in mutants that lacked Hfq or RNase III, or which expressed a truncated RNase E (rne701). We found that translational regulation by these sRNAs was largely independent of full-length RNase E, e.g. despite the fact that ompA fusion mRNA decay could no longer be promoted by MicA. This is the first study in which multiple well-defined E.coli sRNA target pairs have been studied in a uniform manner in vivo. We expect our GFP fusion approach to be applicable to sRNA targets of other bacteria, and also demonstrate that Vibrio RyhB sRNA represses a Vibrio sodB fusion when co-expressed in E.coli. PMID:17264113

  2. Early recognition of lung cancer by integrin targeted imaging in K-ras mouse model.

    PubMed

    Ermolayev, Vladimir; Mohajerani, Pouyan; Ale, Angelique; Sarantopoulos, Athanasios; Aichler, Michaela; Kayser, Gian; Walch, Axel; Ntziachristos, Vasilis

    2015-09-01

    Non-small cell lung cancer is characterized by slow progression and high heterogeneity of tumors. Integrins play an important role in lung cancer development and metastasis and were suggested as a tumor marker; however their role in anticancer therapy remains controversial. In this work, we demonstrate the potential of integrin-targeted imaging to recognize early lesions in transgenic mouse model of lung cancer based on spontaneous introduction of mutated human gene bearing K-ras mutation. We conducted ex vivo and fluorescence molecular tomography-X-ray computed tomography (FMT-XCT) in vivo imaging and analysis for specific targeting of early lung lesions and tumors in rodent preclinical model for lung cancer. The lesions and tumors were characterized by histology, immunofluorescence and immunohistochemistry using a panel of cancer markers. Ex vivo, the integrin-targeted fluorescent signal significantly differed between wild type lung tissue and K-ras pulmonary lesions (PL) at all ages studied. The panel of immunofluorescence experiments demonstrated that PL, which only partially show cancer cell features were detected by αvβ3-integrin targeted imaging. Human patient material analysis confirmed the specificity of target localization in different lung cancer types. Most importantly, small tumors in the lungs of 4-week-old animals could be noninvasively detected in vivo on the fluorescence channel of FMT-XCT. Our findings demonstrated αvβ3-integrin targeted fluorescent imaging to specifically detect premalignant pleural lesions in K-ras mice. Integrin targeted imaging may find application areas in preclinical research and clinical practice, such as early lung cancer diagnostics, intraoperative assistance or therapy monitoring.

  3. Nbs1 ChIP-Seq Identifies Off-Target DNA Double-Strand Breaks Induced by AID in Activated Splenic B Cells.

    PubMed

    Khair, Lyne; Baker, Richard E; Linehan, Erin K; Schrader, Carol E; Stavnezer, Janet

    2015-08-01

    Activation-induced cytidine deaminase (AID) is required for initiation of Ig class switch recombination (CSR) and somatic hypermutation (SHM) of antibody genes during immune responses. AID has also been shown to induce chromosomal translocations, mutations, and DNA double-strand breaks (DSBs) involving non-Ig genes in activated B cells. To determine what makes a DNA site a target for AID-induced DSBs, we identify off-target DSBs induced by AID by performing chromatin immunoprecipitation (ChIP) for Nbs1, a protein that binds DSBs, followed by deep sequencing (ChIP-Seq). We detect and characterize hundreds of off-target AID-dependent DSBs. Two types of tandem repeats are highly enriched within the Nbs1-binding sites: long CA repeats, which can form Z-DNA, and tandem pentamers containing the AID target hotspot WGCW. These tandem repeats are not nearly as enriched at AID-independent DSBs, which we also identified. Msh2, a component of the mismatch repair pathway and important for genome stability, increases off-target DSBs, similar to its effect on Ig switch region DSBs, which are required intermediates during CSR. Most of the off-target DSBs are two-ended, consistent with generation during G1 phase, similar to DSBs in Ig switch regions. However, a minority are one-ended, presumably due to conversion of single-strand breaks to DSBs during replication. One-ended DSBs are repaired by processes involving homologous recombination, including break-induced replication repair, which can lead to genome instability. Off-target DSBs, especially those present during S phase, can lead to chromosomal translocations, deletions and gene amplifications, resulting in the high frequency of B cell lymphomas derived from cells that express or have expressed AID.

  4. Cultural targeting and tailoring of shared decision making technology: a theoretical framework for improving the effectiveness of patient decision aids in culturally diverse groups.

    PubMed

    Alden, Dana L; Friend, John; Schapira, Marilyn; Stiggelbout, Anne

    2014-03-01

    Patient decision aids are known to positively impact outcomes critical to shared decision making (SDM), such as gist knowledge and decision preparedness. However, research on the potential improvement of these and other important outcomes through cultural targeting and tailoring of decision aids is very limited. This is the case despite extensive evidence supporting use of cultural targeting and tailoring to improve the effectiveness of health communications. Building on prominent psychological theory, we propose a two-stage framework incorporating cultural concepts into the design process for screening and treatment decision aids. The first phase recommends use of cultural constructs, such as collectivism and individualism, to differentially target patients whose cultures are known to vary on these dimensions. Decision aid targeting is operationalized through use of symbols and values that appeal to members of the given culture. Content dimensions within decision aids that appear particularly appropriate for targeting include surface level visual characteristics, language, beliefs, attitudes and values. The second phase of the framework is based on evidence that individuals vary in terms of how strongly cultural norms influence their approach to problem solving and decision making. In particular, the framework hypothesizes that differences in terms of access to cultural mindsets (e.g., access to interdependent versus independent self) can be measured up front and used to tailor decision aids. Thus, the second phase in the framework emphasizes the importance of not only targeting decision aid content, but also tailoring the information to the individual based on measurement of how strongly he/she is connected to dominant cultural mindsets. Overall, the framework provides a theory-based guide for researchers and practitioners who are interested in using cultural targeting and tailoring to develop and test decision aids that move beyond a "one-size fits all" approach

  5. Cultural targeting and tailoring of shared decision making technology: a theoretical framework for improving the effectiveness of patient decision aids in culturally diverse groups.

    PubMed

    Alden, Dana L; Friend, John; Schapira, Marilyn; Stiggelbout, Anne

    2014-03-01

    Patient decision aids are known to positively impact outcomes critical to shared decision making (SDM), such as gist knowledge and decision preparedness. However, research on the potential improvement of these and other important outcomes through cultural targeting and tailoring of decision aids is very limited. This is the case despite extensive evidence supporting use of cultural targeting and tailoring to improve the effectiveness of health communications. Building on prominent psychological theory, we propose a two-stage framework incorporating cultural concepts into the design process for screening and treatment decision aids. The first phase recommends use of cultural constructs, such as collectivism and individualism, to differentially target patients whose cultures are known to vary on these dimensions. Decision aid targeting is operationalized through use of symbols and values that appeal to members of the given culture. Content dimensions within decision aids that appear particularly appropriate for targeting include surface level visual characteristics, language, beliefs, attitudes and values. The second phase of the framework is based on evidence that individuals vary in terms of how strongly cultural norms influence their approach to problem solving and decision making. In particular, the framework hypothesizes that differences in terms of access to cultural mindsets (e.g., access to interdependent versus independent self) can be measured up front and used to tailor decision aids. Thus, the second phase in the framework emphasizes the importance of not only targeting decision aid content, but also tailoring the information to the individual based on measurement of how strongly he/she is connected to dominant cultural mindsets. Overall, the framework provides a theory-based guide for researchers and practitioners who are interested in using cultural targeting and tailoring to develop and test decision aids that move beyond a "one-size fits all" approach

  6. CRISPR-Cas9 nuclear dynamics and target recognition in living cells.

    PubMed

    Ma, Hanhui; Tu, Li-Chun; Naseri, Ardalan; Huisman, Maximiliaan; Zhang, Shaojie; Grunwald, David; Pederson, Thoru

    2016-08-29

    The bacterial CRISPR-Cas9 system has been repurposed for genome engineering, transcription modulation, and chromosome imaging in eukaryotic cells. However, the nuclear dynamics of clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (Cas9) guide RNAs and target interrogation are not well defined in living cells. Here, we deployed a dual-color CRISPR system to directly measure the stability of both Cas9 and guide RNA. We found that Cas9 is essential for guide RNA stability and that the nuclear Cas9-guide RNA complex levels limit the targeting efficiency. Fluorescence recovery after photobleaching measurements revealed that single mismatches in the guide RNA seed sequence reduce the target residence time from >3 h to as low as <2 min in a nucleotide identity- and position-dependent manner. We further show that the duration of target residence correlates with cleavage activity. These results reveal that CRISPR discriminates between genuine versus mismatched targets for genome editing via radical alterations in residence time.

  7. CRISPR-Cas9 nuclear dynamics and target recognition in living cells.

    PubMed

    Ma, Hanhui; Tu, Li-Chun; Naseri, Ardalan; Huisman, Maximiliaan; Zhang, Shaojie; Grunwald, David; Pederson, Thoru

    2016-08-29

    The bacterial CRISPR-Cas9 system has been repurposed for genome engineering, transcription modulation, and chromosome imaging in eukaryotic cells. However, the nuclear dynamics of clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (Cas9) guide RNAs and target interrogation are not well defined in living cells. Here, we deployed a dual-color CRISPR system to directly measure the stability of both Cas9 and guide RNA. We found that Cas9 is essential for guide RNA stability and that the nuclear Cas9-guide RNA complex levels limit the targeting efficiency. Fluorescence recovery after photobleaching measurements revealed that single mismatches in the guide RNA seed sequence reduce the target residence time from >3 h to as low as <2 min in a nucleotide identity- and position-dependent manner. We further show that the duration of target residence correlates with cleavage activity. These results reveal that CRISPR discriminates between genuine versus mismatched targets for genome editing via radical alterations in residence time. PMID:27551060

  8. Recognition and sensing of low-epitope targets via ternary complexes with oligonucleotides and synthetic receptors

    NASA Astrophysics Data System (ADS)

    Yang, Kyung-Ae; Barbu, Mihaela; Halim, Marlin; Pallavi, Payal; Kim, Benjamin; Kolpashchikov, Dmitry M.; Pecic, Stevan; Taylor, Steven; Worgall, Tilla S.; Stojanovic, Milan N.

    2014-11-01

    Oligonucleotide-based receptors or aptamers can interact with small molecules, but the ability to achieve high-affinity and specificity of these interactions depends strongly on functional groups or epitopes displayed by the binding targets. Some classes of targets are particularly challenging: for example, monosaccharides have scarce functionalities and no aptamers have been reported to recognize, let alone distinguish from each other, glucose and other hexoses. Here we report aptamers that differentiate low-epitope targets such as glucose, fructose or galactose by forming ternary complexes with high-epitope organic receptors for monosaccharides. In a follow-up example, we expand this method to isolate high-affinity oligonucleotides against aromatic amino acids complexed in situ with a nonspecific organometallic receptor. The method is general and enables broad clinical use of aptamers for the detection of small molecules in mix-and-measure assays, as demonstrated by monitoring postprandial waves of phenylalanine in human subjects.

  9. Recognition and sensing of low-epitope targets via ternary complexes with oligonucleotides and synthetic receptors.

    PubMed

    Yang, Kyung-Ae; Barbu, Mihaela; Halim, Marlin; Pallavi, Payal; Kim, Benjamin; Kolpashchikov, Dmitry M; Pecic, Stevan; Taylor, Steven; Worgall, Tilla S; Stojanovic, Milan N

    2014-11-01

    Oligonucleotide-based receptors or aptamers can interact with small molecules, but the ability to achieve high-affinity and specificity of these interactions depends strongly on functional groups or epitopes displayed by the binding targets. Some classes of targets are particularly challenging: for example, monosaccharides have scarce functionalities and no aptamers have been reported to recognize, let alone distinguish from each other, glucose and other hexoses. Here we report aptamers that differentiate low-epitope targets such as glucose, fructose or galactose by forming ternary complexes with high-epitope organic receptors for monosaccharides. In a follow-up example, we expand this method to isolate high-affinity oligonucleotides against aromatic amino acids complexed in situ with a nonspecific organometallic receptor. The method is general and enables broad clinical use of aptamers for the detection of small molecules in mix-and-measure assays, as demonstrated by monitoring postprandial waves of phenylalanine in human subjects. PMID:25343606

  10. Recognition and Sensing of Low-Epitope Targets via Ternary Complexes with Oligonucleotides and Synthetic Receptors

    PubMed Central

    Yang, Kyung-Ae; Barbu, Michaela; Halim, Marlin; Pallavi, Payal; Kim, Benjamin; Kolpashchikov, Dmitry; Pecic, Stevan; Taylor, Steven; Worgall, Tilla S.; Stojanovic, Milan N.

    2015-01-01

    Oligonucleotide-based receptors or aptamers can interact with small molecules, but the ability to achieve high-affinity and selectivity of these interactions depends strongly on functional groups or epitopes displayed by the binding targets. Some classes of targets are particularly challenging: for example, monosaccharides have scarce functionalities and no aptamers have been reported to recognize, let alone distinguish from each other, glucose and other hexoses. Here we report aptamers that differentiate low-epitope targets such as glucose, fructose, or galactose by forming ternary complexes with high-epitope organic receptors for monosaccharides. In a follow-up example, we expand this method to isolate high-affinity oligonucleotides against aromatic amino acids complexed in situ with a non-specific organometallic receptor. The method is general and enables broad clinical use of aptamers for detection of small molecules in mix-and-measure assays, as demonstrated by monitoring postprandial waves of phenylalanine in human subjects. PMID:25343606

  11. Evaluation of Waveform Structure Features on Time Domain Target Recognition under Cross Polarization

    NASA Astrophysics Data System (ADS)

    Selver, M. A.; Seçmen, M.; Zoral, E. Y.

    2016-08-01

    Classification of aircraft targets from scattered electromagnetic waves is a challenging application, which suffers from aspect angle dependency. In order to eliminate the adverse effects of aspect angle, various strategies were developed including the techniques that rely on extraction of several features and design of suitable classification systems to process them. Recently, a hierarchical method, which uses features that take advantage of waveform structure of the scattered signals, is introduced and shown to have effective results. However, this approach has been applied to the special cases that consider only a single planar component of electric field that cause no-cross polarization at the observation point. In this study, two small scale aircraft models, Boeing-747 and DC-10, are selected as the targets and various polarizations are used to analyse the cross-polarization effects on system performance of the aforementioned method. The results reveal the advantages and the shortcomings of using waveform structures in time-domain target identification.

  12. A bio-recognition device developed onto nano-crystals of carbonate apatite for cell-targeted gene delivery.

    PubMed

    Chowdhury, E H; Akaike, Toshihiro

    2005-05-20

    The DNA delivery to mammalian cells is an essential tool for analyzing gene structure, regulation, and function. The approach holds great promise for the further development of gene therapy techniques and DNA vaccination strategies to treat and control diseases. Here, we report on the establishment of a cell-specific gene delivery and expression system by physical adsorption of a cell-recognition molecule on the nano-crystal surface of carbonate apatite. As a model, DNA/nano-particles were successfully coated with asialofetuin to facilitate uptake by hepatocyte-derived cell lines through the asialoglycoprotein receptor (ASGPr) and albumin to prevent non-specific interactions of the particles with cell-surface. The resulting composite particles with dual surface properties could accelerate DNA uptake and enhance expression to a notable extent. Nano-particles coated with transferrin in the same manner dramatically enhanced transgene expression in the corresponding receptor-bearing cells and thus our newly developed strategy represents a universal phenomenon for anchoring a bio-recognition macromolecule on the apatite crystal surface for targeted gene delivery, having immediate applications in basic research laboratories and great promise for gene therapy.

  13. General Metropolis-Hastings jump diffusions for automatic target recognition in infrared scenes

    NASA Astrophysics Data System (ADS)

    Lanterman, Aaron D.; Miller, Michael I.; Snyder, Donald L.

    1997-04-01

    To locate and recognize ground-based targets in forward- looking IR (FLIR) images, 3D faceted models with associated pose parameters are formulated to accommodate the variability found in FLIR imagery. Taking a Bayesian approach, scenes are simulated from the emissive characteristics of the CAD models and compared with the collected data by a likelihood function based on sensor statistics. This likelihood is combined with a prior distribution defined over the set of possible scenes to form a posterior distribution. To accommodate scenes with variable numbers of targets, the posterior distribution is defined over parameter vectors of varying dimension. An inference algorithm based on Metropolis-Hastings jump- diffusion processes empirically samples from the posterior distribution, generating configurations of templates and transformations that match the collected sensor data with high probability. The jumps accommodate the addition and deletion of targets and the estimation of target identities; diffusions refine the hypotheses by drifting along the gradient of the posterior distribution with respect to the orientation and position parameters. Previous results on jumps strategies analogous to the Metropolis acceptance/rejection algorithm, with proposals drawn from the prior and accepted based on the likelihood, are extended to encompass general Metropolis-Hastings proposal densities. In particular, the algorithm proposes moves by drawing from the posterior distribution over computationally tractible subsets of the parameter space. The algorithm is illustrated by an implementation on a Silicon Graphics Onyx/Reality Engine.

  14. Recognition of dual targets by a molecular beacon-based sensor: subtyping of influenza A virus.

    PubMed

    Lee, Chun-Ching; Liao, Yu-Chieh; Lai, Yu-Hsuan; Lee, Chang-Chun David; Chuang, Min-Chieh

    2015-01-01

    A molecular beacon (MB)-based sensor to offer a decisive answer in combination with information originated from dual-target inputs is designed. The system harnesses an assistant strand and thermodynamically favored designation of unpaired nucleotides (UNs) to process the binary targets in "AND-gate" format and report fluorescence in "off-on" mechanism via a formation of a DNA four-way junction (4WJ). By manipulating composition of the UNs, the dynamic fluorescence difference between the binary targets-coexisting circumstance and any other scenario was maximized. Characteristic equilibrium constant (K), change of entropy (ΔS), and association rate constant (k) between the association ("on") and dissociation ("off") states of the 4WJ were evaluated to understand unfolding behavior of MB in connection to its sensing capability. Favorable MB and UNs were furthermore designed toward analysis of genuine genetic sequences of hemagglutinin (HA) and neuraminidase (NA) in an influenza A H5N2 isolate. The MB-based sensor was demonstrated to yield a linear calibration range from 1.2 to 240 nM and detection limit of 120 pM. Furthermore, high-fidelity subtyping of influenza virus was implemented in a sample of unpurified amplicons. The strategy opens an alternative avenue of MB-based sensors for dual targets toward applications in clinical diagnosis.

  15. Contributions of Qualitative Research in Informing HIV/AIDS Interventions Targeting Black MSM in the United States.

    PubMed

    Wilson, Patrick A; Valera, Pamela; Martos, Alexander J; Wittlin, Natalie M; Muñoz-Laboy, Miguel A; Parker, Richard G

    2016-01-01

    This article presents a systematic review of qualitative studies focusing on human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) among Black men who have sex with men (BMSM) in the United States. We reviewed studies that were published between 1980 and 2014. Qualitative methods employed in the studies reviewed include in-depth interviews, focus groups, participant observation, and ethnography. We searched several databases (PubMed, PsychINFO, JSTOR, ERIC, Sociological Abstracts, and Google Scholar) for relevant articles using the following broad terms: "Black men" "Black gay/bisexual" or "Black men who have sex with men," and "qualitative" and/or "ethnography." We include 70 studies in this review. The key themes observed across studies were (1) heterogeneity, (2) layered stigma and intersectionality, (3) risk behaviors, (4) mental health, (5) resilience, and (6) community engagement. The review suggests that sexual behavior and HIV-status disclosure, sexual risk taking, substance use, and psychological well-being were contextually situated. Interventions occurring at multiple levels and within multiple contexts are needed to reduce stigma within the Black community. Similarly, structural interventions targeting religious groups, schools, and health care systems are needed to improve the health outcomes among BMSM. Community engagement and using community-based participatory research methods may facilitate the development and implementation of culturally appropriate HIV/AIDS interventions targeting BMSM. PMID:26241373

  16. Contributions of Qualitative Research in Informing HIV/AIDS Interventions Targeting Black MSM in the United States.

    PubMed

    Wilson, Patrick A; Valera, Pamela; Martos, Alexander J; Wittlin, Natalie M; Muñoz-Laboy, Miguel A; Parker, Richard G

    2016-01-01

    This article presents a systematic review of qualitative studies focusing on human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) among Black men who have sex with men (BMSM) in the United States. We reviewed studies that were published between 1980 and 2014. Qualitative methods employed in the studies reviewed include in-depth interviews, focus groups, participant observation, and ethnography. We searched several databases (PubMed, PsychINFO, JSTOR, ERIC, Sociological Abstracts, and Google Scholar) for relevant articles using the following broad terms: "Black men" "Black gay/bisexual" or "Black men who have sex with men," and "qualitative" and/or "ethnography." We include 70 studies in this review. The key themes observed across studies were (1) heterogeneity, (2) layered stigma and intersectionality, (3) risk behaviors, (4) mental health, (5) resilience, and (6) community engagement. The review suggests that sexual behavior and HIV-status disclosure, sexual risk taking, substance use, and psychological well-being were contextually situated. Interventions occurring at multiple levels and within multiple contexts are needed to reduce stigma within the Black community. Similarly, structural interventions targeting religious groups, schools, and health care systems are needed to improve the health outcomes among BMSM. Community engagement and using community-based participatory research methods may facilitate the development and implementation of culturally appropriate HIV/AIDS interventions targeting BMSM.

  17. Contributions of Qualitative Research in Informing HIV/AIDS Interventions Targeting Black MSM in the United States

    PubMed Central

    Wilson, Patrick A.; Valera, Pamela; Martos, Alexander J.; Wittlin, Natalie M.; Muñoz-Laboy, Miguel A.; Parker, Richard G.

    2015-01-01

    This article presents a systematic review of qualitative studies focusing on the Human Immunodeficiency Virus (HIV) and Acquired Immune Deficiency Syndrome (AIDS) among Black men who have sex with men (BMSM) in the United States. We reviewed studies that were published between 1980-2014. Qualitative methods employed in the studies reviewed include: in-depth interviews, focus groups, participant observation, and ethnography. We searched the following databases: PubMed, PsychINFO, JSTOR, ERIC, Sociological Abstracts, and Google Scholar for relevant articles using the following broad terms: “Black men” and/or “BMSM,” and “qualitative” and/or “ethnography.” Seventy studies were included in this review. The key themes observed across studies were: (1) heterogeneity, (2) layered stigma and intersectionality, (3) risk behaviors, (4) mental health, (5) resilience, and (6) community engagement. The review suggests that sexual behavior and HIV-status disclosure, sexual risk-taking, substance use, and psychological well-being were contextually situated. Interventions occurring at multiple levels and within multiple contexts are needed to reduce stigma within the Black community. Similarly, structural interventions targeting religious groups, schools, and health care systems are needed to improve the health outcomes among BMSM. Community engagement and using community-based participatory research methods may facilitate the development and implementation of culturally appropriate HIV/AIDS interventions targeting BMSM. PMID:26241373

  18. Information theoretic partitioning and confidence based weight assignment for multi-classifier decision level fusion in hyperspectral target recognition applications

    NASA Astrophysics Data System (ADS)

    Prasad, S.; Bruce, L. M.

    2007-04-01

    There is a growing interest in using multiple sources for automatic target recognition (ATR) applications. One approach is to take multiple, independent observations of a phenomenon and perform a feature level or a decision level fusion for ATR. This paper proposes a method to utilize these types of multi-source fusion techniques to exploit hyperspectral data when only a small number of training pixels are available. Conventional hyperspectral image based ATR techniques project the high dimensional reflectance signature onto a lower dimensional subspace using techniques such as Principal Components Analysis (PCA), Fisher's linear discriminant analysis (LDA), subspace LDA and stepwise LDA. While some of these techniques attempt to solve the curse of dimensionality, or small sample size problem, these are not necessarily optimal projections. In this paper, we present a divide and conquer approach to address the small sample size problem. The hyperspectral space is partitioned into contiguous subspaces such that the discriminative information within each subspace is maximized, and the statistical dependence between subspaces is minimized. We then treat each subspace as a separate source in a multi-source multi-classifier setup and test various decision fusion schemes to determine their efficacy. Unlike previous approaches which use correlation between variables for band grouping, we study the efficacy of higher order statistical information (using average mutual information) for a bottom up band grouping. We also propose a confidence measure based decision fusion technique, where the weights associated with various classifiers are based on their confidence in recognizing the training data. To this end, training accuracies of all classifiers are used for weight assignment in the fusion process of test pixels. The proposed methods are tested using hyperspectral data with known ground truth, such that the efficacy can be quantitatively measured in terms of target

  19. Global identification of target recognition and cleavage by the Microprocessor in human ES cells.

    PubMed

    Seong, Youngmo; Lim, Do-Hwan; Kim, Augustine; Seo, Jae Hong; Lee, Young Sik; Song, Hoseok; Kwon, Young-Soo

    2014-11-10

    The Microprocessor plays an essential role in canonical miRNA biogenesis by facilitating cleavage of stem-loop structures in primary transcripts to yield pre-miRNAs. Although miRNA biogenesis has been extensively studied through biochemical and molecular genetic approaches, it has yet to be addressed to what extent the current miRNA biogenesis models hold true in intact cells. To address the issues of in vivo recognition and cleavage by the Microprocessor, we investigate RNAs that are associated with DGCR8 and Drosha by using immunoprecipitation coupled with next-generation sequencing. Here, we present global protein-RNA interactions with unprecedented sensitivity and specificity. Our data indicate that precursors of canonical miRNAs and miRNA-like hairpins are the major substrates of the Microprocessor. As a result of specific enrichment of nascent cleavage products, we are able to pinpoint the Microprocessor-mediated cleavage sites per se at single-nucleotide resolution. Unexpectedly, a 2-nt 3' overhang invariably exists at the ends of cleaved bases instead of nascent pre-miRNAs. Besides canonical miRNA precursors, we find that two novel miRNA-like structures embedded in mRNAs are cleaved to yield pre-miRNA-like hairpins, uncoupled from miRNA maturation. Our data provide a framework for in vivo Microprocessor-mediated cleavage and a foundation for experimental and computational studies on miRNA biogenesis in living cells.

  20. Sequence-specific recognition of colicin E5, a tRNA-targeting ribonuclease

    PubMed Central

    Ogawa, Tetsuhiro; Inoue, Sakura; Yajima, Shunsuke; Hidaka, Makoto; Masaki, Haruhiko

    2006-01-01

    Colicin E5 is a novel Escherichia coli ribonuclease that specifically cleaves the anticodons of tRNATyr, tRNAHis, tRNAAsn and tRNAAsp. Since this activity is confined to its 115 amino acid long C-terminal domain (CRD), the recognition mechanism of E5-CRD is of great interest. The four tRNA substrates share the unique sequence UQU within their anticodon loops, and are cleaved between Q (modified base of G) and 3′ U. Synthetic minihelix RNAs corresponding to the substrate tRNAs were completely susceptible to E5-CRD and were cleaved in the same manner as the authentic tRNAs. The specificity determinant for E5-CRD was YGUN at −1 to +3 of the ‘anticodon’. The YGU is absolutely required and the extent of susceptibility of minihelices depends on N (third letter of the anticodon) in the order A > C > G > U accounting for the order of susceptibility tRNATyr > tRNAAsp > tRNAHis, tRNAAsn. Contrastingly, we showed that GpUp is the minimal substrate strictly retaining specificity to E5-CRD. The effect of contiguous nucleotides is inconsistent between the loop and linear RNAs, suggesting that nucleotide extension on each side of GpUp introduces a structural constraint, which is reduced by a specific loop structure formation that includes a 5′ pyrimidine and 3′ A. PMID:16963495

  1. Structural basis for specific recognition of multiple mRNA targets by a PUF regulatory protein

    SciTech Connect

    Wang, Yeming; Opperman, Laura; Wickens, Marvin; Tanaka Hall, Traci M.

    2011-11-02

    Caenorhabditis elegans fem-3 binding factor (FBF) is a founding member of the PUMILIO/FBF (PUF) family of mRNA regulatory proteins. It regulates multiple mRNAs critical for stem cell maintenance and germline development. Here, we report crystal structures of FBF in complex with 6 different 9-nt RNA sequences, including elements from 4 natural mRNAs. These structures reveal that FBF binds to conserved bases at positions 1-3 and 7-8. The key specificity determinant of FBF vs. other PUF proteins lies in positions 4-6. In FBF/RNA complexes, these bases stack directly with one another and turn away from the RNA-binding surface. A short region of FBF is sufficient to impart its unique specificity and lies directly opposite the flipped bases. We suggest that this region imposes a flattened curvature on the protein; hence, the requirement for the additional nucleotide. The principles of FBF/RNA recognition suggest a general mechanism by which PUF proteins recognize distinct families of RNAs yet exploit very nearly identical atomic contacts in doing so.

  2. Interaction with WDR5 Promotes Target Gene Recognition and Tumorigenesis by MYC

    PubMed Central

    Thomas, Lance R.; Wang, Qingguo; Grieb, Brian C.; Phan, Jason; Foshage, Audra M.; Sun, Qi; Olejniczak, Edward T.; Clark, Travis; Dey, Soumyadeep; Lorey, Shelly; Alicie, Bethany; Howard, Gregory C.; Cawthon, Bryan; Ess, Kevin C.; Eischen, Christine M.; Zhao, Zhongming; Fesik, Stephen W.; Tansey, William P.

    2015-01-01

    SUMMARY MYC is an oncoprotein transcription factor that is overexpressed in the majority of malignancies. The oncogenic potential of MYC stems from its ability to bind regulatory sequences in thousands of target genes, which depends on interaction of MYC with its obligate partner, MAX. Here, we show that broad association of MYC with chromatin also depends on interaction with the WD40-repeat protein WDR5. MYC binds WDR5 via an evolutionarily conserved “MYC box IIIb” motif that engages a shallow, hydrophobic, cleft on the surface of WDR5. Structure-guided mutations in MYC that disrupt interaction with WDR5 attenuate binding of MYC to ~80% of its chromosomal locations and disable its ability to promote induced pluripotent stem cell formation and drive tumorigenesis. Our data reveal WDR5 as a key determinant for MYC recruitment to chromatin and uncover a tractable target for the discovery of anti-cancer therapies against MYC-driven tumors. PMID:25818646

  3. Joint tracking, pose estimation, and target recognition using HRRR and track data: new results

    NASA Astrophysics Data System (ADS)

    Zajic, Tim; Rago, Constantino; Mahler, Ronald P. S.; Huff, Melvyn; Noviskey, Michael J.

    2001-08-01

    The work presented here is a continuation of research first reported in Mahler, et. Al. Our goal is a generalization of Bayesian filtering and estimation theory to the problem of multisensor, multitarget, multi-evidence unified joint detection, tracking and target identification. Our earlier efforts were focused on integrating the Statistical Features algorithm with a Bayesian nonlinear filter, allowing simultaneous determination of target position, velocity, pose and type via maximum a posteriori estimation. In this paper we continue to address the problem of target classification based on high range resolution radar signatures. While we continue to consider feature based techniques, as in StaF and our earlier work, instead of considering the location and magnitude of peaks in a signature as our features, we consider three alternative features. The features arise from applying either a Wavelet Decomposition, Principal Component Analysis or Linear Discriminant Analysis to the signature. We discuss briefly also, in the wavelet decomposition setting, the challenge of assigning a measure of uncertainty with a classification decision.

  4. Recognition and targeting mechanisms by chaperones in flagellum assembly and operation.

    PubMed

    Khanra, Nandish; Rossi, Paolo; Economou, Anastassios; Kalodimos, Charalampos G

    2016-08-30

    The flagellum is a complex bacterial nanomachine that requires the proper assembly of several different proteins for its function. Dedicated chaperones are central in preventing aggregation or undesired interactions of flagellar proteins, including their targeting to the export gate. FliT is a key flagellar chaperone that binds to several flagellar proteins in the cytoplasm, including its cognate filament-capping protein FliD. We have determined the solution structure of the FliT chaperone in the free state and in complex with FliD and the flagellar ATPase FliI. FliT adopts a four-helix bundle and uses a hydrophobic surface formed by the first three helices to recognize its substrate proteins. We show that the fourth helix constitutes the binding site for FlhA, a membrane protein at the export gate. In the absence of a substrate protein FliT adopts an autoinhibited structure wherein both the binding sites for substrates and FlhA are occluded. Substrate binding to FliT activates the complex for FlhA binding and thus targeting of the chaperone-substrate complex to the export gate. The activation and targeting mechanisms reported for FliT appear to be shared among the other flagellar chaperones. PMID:27528687

  5. Road-Aided Ground Slowly Moving Target 2D Motion Estimation for Single-Channel Synthetic Aperture Radar

    PubMed Central

    Wang, Zhirui; Xu, Jia; Huang, Zuzhen; Zhang, Xudong; Xia, Xiang-Gen; Long, Teng; Bao, Qian

    2016-01-01

    To detect and estimate ground slowly moving targets in airborne single-channel synthetic aperture radar (SAR), a road-aided ground moving target indication (GMTI) algorithm is proposed in this paper. First, the road area is extracted from a focused SAR image based on radar vision. Second, after stationary clutter suppression in the range-Doppler domain, a moving target is detected and located in the image domain via the watershed method. The target’s position on the road as well as its radial velocity can be determined according to the target’s offset distance and traffic rules. Furthermore, the target’s azimuth velocity is estimated based on the road slope obtained via polynomial fitting. Compared with the traditional algorithms, the proposed method can effectively cope with slowly moving targets partly submerged in a stationary clutter spectrum. In addition, the proposed method can be easily extended to a multi-channel system to further improve the performance of clutter suppression and motion estimation. Finally, the results of numerical experiments are provided to demonstrate the effectiveness of the proposed algorithm. PMID:26999140

  6. Molecular mechanisms of target recognition by lipid GPCRs: relevance for cancer.

    PubMed

    van Jaarsveld, M T M; Houthuijzen, J M; Voest, E E

    2016-08-01

    Over the past decade the importance of lipids for cancer cell metabolism and cancer-related processes such as proliferation, metastasis and chemotherapy resistance has become more apparent. The mechanisms by which lipid signals are transduced are poorly understood, but frequently involve G-protein Coupled Receptors (GPCRs), which can be explored as druggable targets. Here, we discuss how GPCRs recognize four classes of cancer-relevant lipids (lysophospholipids, phospholipids, fatty acids and eicosanoids). We compare the ligand-binding properties of >50 lipid receptors, we examine how their dysregulation contributes to tumorigenesis and how they may be therapeutically exploited. PMID:26640151

  7. The Importance and Use of Targeted Content Knowledge with Scaffolding Aid in Educational Simulation Games

    ERIC Educational Resources Information Center

    Tsai, Fu-Hsing; Kinzer, Charles; Hung, Kuo-Hsun; Chen, Cheng-Ling Alice; Hsu, I-Ying

    2013-01-01

    While most current educational simulation games provide learners with gameplay experience to motivate learning, there is often a lack of focus on ensuring that the desired content knowledge is actually learned. Students may focus on completing game activities without learning the targeted content knowledge, thus negating the desired learning…

  8. Sensitive and selective amplified fluorescence DNA detection based on exonuclease III-aided target recycling.

    PubMed

    Zuo, Xiaolei; Xia, Fan; Xiao, Yi; Plaxco, Kevin W

    2010-02-17

    A limitation of many traditional approaches to the detection of specific oligonucleotide sequences, such as molecular beacons, is that each target strand hybridizes with (and thus activates) only a single copy of the relevant probe sequence. This 1:1 hybridization ratio limits the gain of most approaches and thus their sensitivity. Here we demonstrate a nuclease-amplified DNA detection scheme in which exonuclease III is used to "recycle" target molecules, thus leading to greatly improved sensitivity relative to, for example, traditional molecular beacons without any significant restriction in the choice of target sequences. The exonuclease-amplified assay can detect target DNA at concentrations as low as 10 pM when performed at 37 degrees C, which represents a significant improvement over the equivalent molecular beacon alone. Moreover, at 4 degrees C we can obtain a detection limit as low as 20 aM, albeit at the cost of a 24 h incubation period. Finally, our assay can be easily interrogated with the naked eye and is thus amenable to deployment in the developing world, where fluorometric detection is more problematic.

  9. Engineering self-contained DNA circuit for proximity recognition and localized signal amplification of target biomolecules

    PubMed Central

    Ang, Yan Shan; Yung, Lin-Yue Lanry

    2014-01-01

    Biomolecular interactions have important cellular implications, however, a simple method for the sensing of such proximal events is lacking in the current molecular toolbox. We designed a dynamic DNA circuit capable of recognizing targets in close proximity to initiate a pre-programmed signal transduction process resulting in localized signal amplification. The entire circuit was engineered to be self-contained, i.e. it can self-assemble onto individual target molecules autonomously and form localized signal with minimal cross-talk. α-thrombin was used as a model protein to evaluate the performance of the individual modules and the overall circuit for proximity interaction under physiologically relevant buffer condition. The circuit achieved good selectivity in presence of non-specific protein and interfering serum matrix and successfully detected for physiologically relevant α-thrombin concentration (50 nM–5 μM) in a single mixing step without any further washing. The formation of localized signal at the interaction site can be enhanced kinetically through the control of temperature and probe concentration. This work provides a basic general framework from which other circuit modules can be adapted for the sensing of other biomolecular or cellular interaction of interest. PMID:25056307

  10. Cancer cell-selective promoter recognition accompanies antitumor effect by glucocorticoid receptor-targeted gold nanoparticle.

    PubMed

    Sau, Samaresh; Agarwalla, Pritha; Mukherjee, Sudip; Bag, Indira; Sreedhar, Bojja; Pal-Bhadra, Manika; Patra, Chitta Ranjan; Banerjee, Rajkumar

    2014-06-21

    Nanoparticles, such as gold nanoparticles (GNP), upon convenient modifications perform multi tasks catering to many biomedical applications. However, GNP or any other type of nanoparticles is yet to achieve the feat of intracellular regulation of endogenous genes of choice such as through manipulation of a gene-promoter in a chromosome. As for gene modulation and delivery, GNP (or other nanoparticles) showed only limited gene therapy potential, which relied on the delivery of 'exogenous' genes invoking gene knockdown or replacement. Practically, there are no instances for the nanoparticle-mediated promoter regulation of 'endogenous' genes, more so, as a cancer selective phenomenon. In this regard, we report the development of a simple, easily modifiable GNP-formulation, which promoted/up-regulated the expression of a specific category of 'endogenous' genes, the glucocorticoid responsive genes. This genetic up-regulation was induced in only cancer cells by modified GNP-mediated transcriptional activation of its cytoplasmic receptor, glucocorticoid receptor (GR). Normal cells and their GR remained primarily unperturbed by this GNP-formulation. The most potent gene up-regulating GNP-formulation down-regulated a cancer-specific proliferative signal, phospho-Akt in cancer cells, which accompanied retardation of tumor growth in the murine melanoma model. We show that GR-targeted GNPs may find potential use in the targeting and modulation of genetic information in cancer towards developing novel anticancer therapeutics.

  11. Communication target object recognition for D2D connection with feature size limit

    NASA Astrophysics Data System (ADS)

    Ok, Jiheon; Kim, Soochang; Kim, Young-hoon; Lee, Chulhee

    2015-03-01

    Recently, a new concept of device-to-device (D2D) communication, which is called "point-and-link communication" has attracted great attentions due to its intuitive and simple operation. This approach enables user to communicate with target devices without any pre-identification information such as SSIDs, MAC addresses by selecting the target image displayed on the user's own device. In this paper, we present an efficient object matching algorithm that can be applied to look(point)-and-link communications for mobile services. Due to the limited channel bandwidth and low computational power of mobile terminals, the matching algorithm should satisfy low-complexity, low-memory and realtime requirements. To meet these requirements, we propose fast and robust feature extraction by considering the descriptor size and processing time. The proposed algorithm utilizes a HSV color histogram, SIFT (Scale Invariant Feature Transform) features and object aspect ratios. To reduce the descriptor size under 300 bytes, a limited number of SIFT key points were chosen as feature points and histograms were binarized while maintaining required performance. Experimental results show the robustness and the efficiency of the proposed algorithm.

  12. Targeting CLEC9A delivers antigen to human CD141+ DC for CD4+ and CD8+T cell recognition

    PubMed Central

    Tullett, Kirsteen M.; Leal Rojas, Ingrid M.; Minoda, Yoshihito; Tan, Peck S.; Zhang, Jian-Guo; Smith, Corey; Shortman, Ken; Caminschi, Irina; Lahoud, Mireille H.; Radford, Kristen J.

    2016-01-01

    DC-based vaccines that initiate T cell responses are well tolerated and have demonstrated efficacy for tumor immunotherapy, with the potential to be combined with other therapies. Targeting vaccine antigens (Ag) directly to the DCs in vivo is more effective than cell-based therapies in mouse models and is therefore a promising strategy to translate to humans. The human CD141+ DCs are considered the most clinically relevant for initiating CD8+ T cell responses critical for killing tumors or infected cells, and they specifically express the C-type lectin-like receptor CLEC9A that facilitates presentation of Ag by these DCs. We have therefore developed a human chimeric Ab that specifically targets CLEC9A on CD141+ DCs in vitro and in vivo. These human chimeric Abs are highly effective at delivering Ag to DCs for recognition by both CD4+ and CD8+ T cells. Given the importance of these cellular responses for antitumor or antiviral immunity, and the superior specificity of anti-CLEC9A Abs for this DC subset, this approach warrants further development for vaccines.

  13. Structures of the Signal Recognition Particle Receptor From the Archaeon Pyrococcus Furiosus: Implications for the Targeting Step at the Membrane

    SciTech Connect

    Egea, P.F.; Tsuruta, H.; Leon, G.P.de; Napetschnig, J.; Walter, P.; Stroud, R.M.

    2009-05-18

    In all organisms, a ribonucleoprotein called the signal recognition particle (SRP) and its receptor (SR) target nascent proteins from the ribosome to the translocon for secretion or membrane insertion. We present the first X-ray structures of an archeal FtsY, the receptor from the hyper-thermophile Pyrococcus furiosus (Pfu), in its free and GDP {center_dot} magnesium-bound forms. The highly charged N-terminal domain of Pfu-FtsY is distinguished by a long N-terminal helix. The basic charges on the surface of this helix are likely to regulate interactions at the membrane. A peripheral GDP bound near a regulatory motif could indicate a site of interaction between the receptor and ribosomal or SRP RNAs. Small angle X-ray scattering and analytical ultracentrifugation indicate that the crystal structure of Pfu-FtsY correlates well with the average conformation in solution. Based on previous structures of two sub-complexes, we propose a model of the core of archeal and eukaryotic SRP {center_dot} SR targeting complexes.

  14. Structures of the Signal Recognition Particle Receptor from the Archaeon Pyrococcus furiosus: Implications for the Targeting Step at the Membrane

    PubMed Central

    Egea, Pascal F.; Tsuruta, Hiro; de Leon, Gladys P.; Napetschnig, Johanna; Walter, Peter; Stroud, Robert M.

    2008-01-01

    In all organisms, a ribonucleoprotein called the signal recognition particle (SRP) and its receptor (SR) target nascent proteins from the ribosome to the translocon for secretion or membrane insertion. We present the first X-ray structures of an archeal FtsY, the receptor from the hyper-thermophile Pyrococcus furiosus (Pfu), in its free and GDP•magnesium-bound forms. The highly charged N-terminal domain of Pfu-FtsY is distinguished by a long N-terminal helix. The basic charges on the surface of this helix are likely to regulate interactions at the membrane. A peripheral GDP bound near a regulatory motif could indicate a site of interaction between the receptor and ribosomal or SRP RNAs. Small angle X-ray scattering and analytical ultracentrifugation indicate that the crystal structure of Pfu-FtsY correlates well with the average conformation in solution. Based on previous structures of two sub-complexes, we propose a model of the core of archeal and eukaryotic SRP•SR targeting complexes. PMID:18978942

  15. Targeting CLEC9A delivers antigen to human CD141+ DC for CD4+ and CD8+T cell recognition

    PubMed Central

    Tullett, Kirsteen M.; Leal Rojas, Ingrid M.; Minoda, Yoshihito; Tan, Peck S.; Zhang, Jian-Guo; Smith, Corey; Shortman, Ken; Caminschi, Irina; Lahoud, Mireille H.; Radford, Kristen J.

    2016-01-01

    DC-based vaccines that initiate T cell responses are well tolerated and have demonstrated efficacy for tumor immunotherapy, with the potential to be combined with other therapies. Targeting vaccine antigens (Ag) directly to the DCs in vivo is more effective than cell-based therapies in mouse models and is therefore a promising strategy to translate to humans. The human CD141+ DCs are considered the most clinically relevant for initiating CD8+ T cell responses critical for killing tumors or infected cells, and they specifically express the C-type lectin-like receptor CLEC9A that facilitates presentation of Ag by these DCs. We have therefore developed a human chimeric Ab that specifically targets CLEC9A on CD141+ DCs in vitro and in vivo. These human chimeric Abs are highly effective at delivering Ag to DCs for recognition by both CD4+ and CD8+ T cells. Given the importance of these cellular responses for antitumor or antiviral immunity, and the superior specificity of anti-CLEC9A Abs for this DC subset, this approach warrants further development for vaccines. PMID:27699265

  16. Functional Analysis of Semi-conserved Transit Peptide Motifs and Mechanistic Implications in Precursor Targeting and Recognition.

    PubMed

    Holbrook, Kristen; Subramanian, Chitra; Chotewutmontri, Prakitchai; Reddick, L Evan; Wright, Sarah; Zhang, Huixia; Moncrief, Lily; Bruce, Barry D

    2016-09-01

    Over 95% of plastid proteins are nuclear-encoded as their precursors containing an N-terminal extension known as the transit peptide (TP). Although highly variable, TPs direct the precursors through a conserved, posttranslational mechanism involving translocons in the outer (TOC) and inner envelope (TOC). The organelle import specificity is mediated by one or more components of the Toc complex. However, the high TP diversity creates a paradox on how the sequences can be specifically recognized. An emerging model of TP design is that they contain multiple loosely conserved motifs that are recognized at different steps in the targeting and transport process. Bioinformatics has demonstrated that many TPs contain semi-conserved physicochemical motifs, termed FGLK. In order to characterize FGLK motifs in TP recognition and import, we have analyzed two well-studied TPs from the precursor of RuBisCO small subunit (SStp) and ferredoxin (Fdtp). Both SStp and Fdtp contain two FGLK motifs. Analysis of large set mutations (∼85) in these two motifs using in vitro, in organello, and in vivo approaches support a model in which the FGLK domains mediate interaction with TOC34 and possibly other TOC components. In vivo import analysis suggests that multiple FGLK motifs are functionally redundant. Furthermore, we discuss how FGLK motifs are required for efficient precursor protein import and how these elements may permit a convergent function of this highly variable class of targeting sequences. PMID:27378725

  17. Cancer cell-selective promoter recognition accompanies antitumor effect by glucocorticoid receptor-targeted gold nanoparticle

    NASA Astrophysics Data System (ADS)

    Sau, Samaresh; Agarwalla, Pritha; Mukherjee, Sudip; Bag, Indira; Sreedhar, Bojja; Pal-Bhadra, Manika; Patra, Chitta Ranjan; Banerjee, Rajkumar

    2014-05-01

    Nanoparticles, such as gold nanoparticles (GNP), upon convenient modifications perform multi tasks catering to many biomedical applications. However, GNP or any other type of nanoparticles is yet to achieve the feat of intracellular regulation of endogenous genes of choice such as through manipulation of a gene-promoter in a chromosome. As for gene modulation and delivery, GNP (or other nanoparticles) showed only limited gene therapy potential, which relied on the delivery of `exogenous' genes invoking gene knockdown or replacement. Practically, there are no instances for the nanoparticle-mediated promoter regulation of `endogenous' genes, more so, as a cancer selective phenomenon. In this regard, we report the development of a simple, easily modifiable GNP-formulation, which promoted/up-regulated the expression of a specific category of `endogenous' genes, the glucocorticoid responsive genes. This genetic up-regulation was induced in only cancer cells by modified GNP-mediated transcriptional activation of its cytoplasmic receptor, glucocorticoid receptor (GR). Normal cells and their GR remained primarily unperturbed by this GNP-formulation. The most potent gene up-regulating GNP-formulation down-regulated a cancer-specific proliferative signal, phospho-Akt in cancer cells, which accompanied retardation of tumor growth in the murine melanoma model. We show that GR-targeted GNPs may find potential use in the targeting and modulation of genetic information in cancer towards developing novel anticancer therapeutics.Nanoparticles, such as gold nanoparticles (GNP), upon convenient modifications perform multi tasks catering to many biomedical applications. However, GNP or any other type of nanoparticles is yet to achieve the feat of intracellular regulation of endogenous genes of choice such as through manipulation of a gene-promoter in a chromosome. As for gene modulation and delivery, GNP (or other nanoparticles) showed only limited gene therapy potential, which relied

  18. Cellular recognition and macropinocytosis-like internalization of nanoparticles targeted to integrin α2β1

    NASA Astrophysics Data System (ADS)

    Kankaanpää, P.; Tiitta, S.; Bergman, L.; Puranen, A.-B.; von Haartman, E.; Lindén, M.; Heino, J.

    2015-10-01

    Targeting nanoparticles to desired intracellular compartments is a major challenge. Integrin-type adhesion receptors are connected to different endocytosis routes in a receptor-specific manner. According to our previous observations, the internalization of an α2β1-integrin-echovirus-1 complex takes place via a macropinocytosis-like mechanism, suggesting that the receptor could be used to target nanoparticles to this specific entry route. Here, silica-based nanoparticles, carrying monoclonal antibodies against the α2β1 integrin as address labels, were synthesized. Studies with flow cytometry, atomic force microscopy and confocal microscopy showed the particles to attach to the cell surface via the α2β1 integrin. Furthermore, quantitative analysis of nanoparticle trafficking inside the cell performed with the BioImageXD software indicated that the particles enter cells via a macropinocytosis-like process and end up in caveolin-1 positive structures. Thus, we suggest that different integrins can guide particles to distinct endocytosis routes and, subsequently, also to specific intracellular compartments. In addition, we show that with the BioImageXD software it is possible to conduct sensitive and complex analyses of the behavior of small fluorescent particles inside cells, using basic confocal microscopy images.Targeting nanoparticles to desired intracellular compartments is a major challenge. Integrin-type adhesion receptors are connected to different endocytosis routes in a receptor-specific manner. According to our previous observations, the internalization of an α2β1-integrin-echovirus-1 complex takes place via a macropinocytosis-like mechanism, suggesting that the receptor could be used to target nanoparticles to this specific entry route. Here, silica-based nanoparticles, carrying monoclonal antibodies against the α2β1 integrin as address labels, were synthesized. Studies with flow cytometry, atomic force microscopy and confocal microscopy showed the

  19. Single cell molecular recognition of migrating and invading tumor cells using a targeted fluorescent probe to receptor PTPmu.

    PubMed

    Burden-Gulley, Susan M; Qutaish, Mohammed Q; Sullivant, Kristin E; Tan, Mingqian; Craig, Sonya E L; Basilion, James P; Lu, Zheng-Rong; Wilson, David L; Brady-Kalnay, Susann M

    2013-04-01

    Detection of an extracellular cleaved fragment of a cell-cell adhesion molecule represents a new paradigm in molecular recognition and imaging of tumors. We previously demonstrated that probes that recognize the cleaved extracellular domain of receptor protein tyrosine phosphatase mu (PTPmu) label human glioblastoma brain tumor sections and the main tumor mass of intracranial xenograft gliomas. In this article, we examine whether one of these probes, SBK2, can label dispersed glioma cells that are no longer connected to the main tumor mass. Live mice with highly dispersive glioma tumors were injected intravenously with the fluorescent PTPmu probe to test the ability of the probe to label the dispersive glioma cells in vivo. Analysis was performed using a unique three-dimensional (3D) cryo-imaging technique to reveal highly migratory and invasive glioma cell dispersal within the brain and the extent of colabeling by the PTPmu probe. The PTPmu probe labeled the main tumor site and dispersed cells up to 3.5 mm away. The cryo-images of tumors labeled with the PTPmu probe provide a novel, high-resolution view of molecular tumor recognition, with excellent 3D detail regarding the pathways of tumor cell migration. Our data demonstrate that the PTPmu probe recognizes distant tumor cells even in parts of the brain where the blood-brain barrier is likely intact. The PTPmu probe has potential translational significance for recognizing tumor cells to facilitate molecular imaging, a more complete tumor resection and to serve as a molecular targeting agent to deliver chemotherapeutics to the main tumor mass and distant dispersive tumor cells.

  20. Targeted reengineering of protein geranylgeranyltransferase type I selectivity functionally implicates active-site residues in protein-substrate recognition.

    PubMed

    Gangopadhyay, Soumyashree A; Losito, Erica L; Hougland, James L

    2014-01-21

    Posttranslational modifications are vital for the function of many proteins. Prenylation is one such modification, wherein protein geranylgeranyltransferase type I (GGTase-I) or protein farnesyltransferase (FTase) modify proteins by attaching a 20- or 15-carbon isoprenoid group, respectively, to a cysteine residue near the C-terminus of a target protein. These enzymes require a C-terminal Ca1a2X sequence on their substrates, with the a1, a2, and X residues serving as substrate-recognition elements for FTase and/or GGTase-I. While crystallographic structures of rat GGTase-I show a tightly packed and hydrophobic a2 residue binding pocket, consistent with a preference for moderately sized a2 residues in GGTase-I substrates, the functional impact of enzyme-substrate contacts within this active site remains to be determined. Using site-directed mutagenesis and peptide substrate structure-activity studies, we have identified specific active-site residues within rat GGTase-I involved in substrate recognition and developed novel GGTase-I variants with expanded/altered substrate selectivity. The ability to drastically alter GGTase-I selectivity mirrors similar behavior observed in FTase but employs mutation of a distinct set of structurally homologous active-site residues. Our work demonstrates that tunable selectivity may be a general phenomenon among multispecific enzymes involved in posttranslational modification and raises the possibility of variable substrate selectivity among GGTase-I orthologues from different organisms. Furthermore, the GGTase-I variants developed herein can serve as tools for studying GGTase-I substrate selectivity and the effects of prenylation pathway modifications on specific proteins. PMID:24344934

  1. Single cell molecular recognition of migrating and invading tumor cells using a targeted fluorescent probe to receptor PTPmu.

    PubMed

    Burden-Gulley, Susan M; Qutaish, Mohammed Q; Sullivant, Kristin E; Tan, Mingqian; Craig, Sonya E L; Basilion, James P; Lu, Zheng-Rong; Wilson, David L; Brady-Kalnay, Susann M

    2013-04-01

    Detection of an extracellular cleaved fragment of a cell-cell adhesion molecule represents a new paradigm in molecular recognition and imaging of tumors. We previously demonstrated that probes that recognize the cleaved extracellular domain of receptor protein tyrosine phosphatase mu (PTPmu) label human glioblastoma brain tumor sections and the main tumor mass of intracranial xenograft gliomas. In this article, we examine whether one of these probes, SBK2, can label dispersed glioma cells that are no longer connected to the main tumor mass. Live mice with highly dispersive glioma tumors were injected intravenously with the fluorescent PTPmu probe to test the ability of the probe to label the dispersive glioma cells in vivo. Analysis was performed using a unique three-dimensional (3D) cryo-imaging technique to reveal highly migratory and invasive glioma cell dispersal within the brain and the extent of colabeling by the PTPmu probe. The PTPmu probe labeled the main tumor site and dispersed cells up to 3.5 mm away. The cryo-images of tumors labeled with the PTPmu probe provide a novel, high-resolution view of molecular tumor recognition, with excellent 3D detail regarding the pathways of tumor cell migration. Our data demonstrate that the PTPmu probe recognizes distant tumor cells even in parts of the brain where the blood-brain barrier is likely intact. The PTPmu probe has potential translational significance for recognizing tumor cells to facilitate molecular imaging, a more complete tumor resection and to serve as a molecular targeting agent to deliver chemotherapeutics to the main tumor mass and distant dispersive tumor cells. PMID:22987116

  2. Active RNAP pre-initiation sites are highly mutated by cytidine deaminases in yeast, with AID targeting small RNA genes

    PubMed Central

    Taylor, Benjamin JM; Wu, Yee Ling; Rada, Cristina

    2014-01-01

    Cytidine deaminases are single stranded DNA mutators diversifying antibodies and restricting viral infection. Improper access to the genome leads to translocations and mutations in B cells and contributes to the mutation landscape in cancer, such as kataegis. It remains unclear how deaminases access double stranded genomes and whether off-target mutations favor certain loci, although transcription and opportunistic access during DNA repair are thought to play a role. In yeast, AID and the catalytic domain of APOBEC3G preferentially mutate transcriptionally active genes within narrow regions, 110 base pairs in width, fixed at RNA polymerase initiation sites. Unlike APOBEC3G, AID shows enhanced mutational preference for small RNA genes (tRNAs, snoRNAs and snRNAs) suggesting a putative role for RNA in its recruitment. We uncover the high affinity of the deaminases for the single stranded DNA exposed by initiating RNA polymerases (a DNA configuration reproduced at stalled polymerases) without a requirement for specific cofactors. DOI: http://dx.doi.org/10.7554/eLife.03553.001 PMID:25237741

  3. Chiral recognition of doxazosin enantiomers in 3 targets for therapy as well as adverse drug reactions in animal experiments.

    PubMed

    Zhao, Ding; Duan, Li-Hua; Wang, Feng-Yu; Wang, Miao; Lu, Hai-Gang; Wu, Zhi-Gang; Wang, Xue; Ren, Lei-Ming

    2012-12-01

    Doxazosin used in benign prostatic hyperplasia has the side effects of causing hypotension and the risk of heart failure. The 3 targets of α(1A)-adrenoceptors (in the prostate), α(1D)-adrenoceptors (in the aorta), and an unknown mechanism (in the heart) are involved, respectively. We hypothesized that there is a chiral recognition of doxazosin enantiomers in the 3 targets. Using isolated rat aorta (α(1D)-adrenoceptors) and rabbit prostate (α(1A)-adrenoceptors), we examined pA(2) and pK(B) values of doxazosin enantiomers. We observed chronotropic and inotropic effects of doxazosin enantiomers in isolated rat and rabbit heart tissues. (-)Doxazosin and (+)doxazosin produced a shift to the right of concentration-contraction curves for noradrenalin (aorta) and phenylephrine (prostate smooth muscle). The pA(2) value of (-)doxazosin (8.625 ± 0.053) was smaller than (+)doxazosin (9.503 ± 0.051) in rat aorta, but their pK(B) values in rabbit prostate were the same. In rat and rabbit heart tissues, (+)doxazosin (3-30 µmol·L(-1)) significantly decreased atrial rate, and produced negative inotropic effects; however, (-)doxazosin did not affect the atrial rate, and produced positive inotropic effects in the atria. Thus, the chiral carbon atom of doxazosin does not affect its activity at the therapeutic target of α(1A)-adrenoceptors in the prostate, but significantly changes its blocking activity against α(1D)-adrenoceptors in the aorta, and produces opposite inotropic effects in the atria via an α(1)-adrenoceptor-independent mechanism.

  4. New detection targets for amyloid-reactive probes: spectroscopic recognition of bacterial spores

    NASA Astrophysics Data System (ADS)

    Jones, Guilford, II; Landsman, Pavel

    2005-05-01

    We report characteristic changes in fluorescence of amyloid-binding dyes Thioflavin T (TfT), pinacyanol (PIN) and related dyes, caused by their interaction with suspended Bacillus spore cultures (B. subtilis, B thuringiensis). The gain in TfT emission in the presence of spores allowed their immediate detection in aqueous suspensions, with a sensitivity limit of < 105 spores per ml. The spectroscopic signatures are consistent with a large number of binding sites for the two dyes on spore coats. The possible structural relationship of these dye binding loci with characteristic motifs (β-stacks) of amyloid deposits and other misfolded protein formations suggests new designs for probing biocontamination and also for clinical studies of non-microbial human pathogens (e.g., amyloid-related protein aggregates in prion-related transmissible encephalopathies or in Alzheimer's disease). Also reported is a special screening technique that was designed and used herein for calibration of new detection probes and assays for spore detection. It employed spectroscopic interactions between the candidate amyloid stains and poly(vinylpyrrolidone)-coated colloid silica (Percoll) nanoparticles that also display remarkable parallelism with the corresponding dye-amyloid and dye-spore reactivities. Percoll may thus find new applications as a convenient non-biological structural model mimicking the putative probe-targeted motifs in both classes of bioanalytes. These findings are important in the design of new probes and assays for important human pathogens (i.e. bacterial spores and amyloidogenic protein aggregates).

  5. A multispectral automatic target recognition application for maritime surveillance, search, and rescue

    NASA Astrophysics Data System (ADS)

    Schoonmaker, Jon; Reed, Scott; Podobna, Yuliya; Vazquez, Jose; Boucher, Cynthia

    2010-04-01

    Due to increased security concerns, the commitment to monitor and maintain security in the maritime environment is increasingly a priority. A country's coast is the most vulnerable area for the incursion of illegal immigrants, terrorists and contraband. This work illustrates the ability of a low-cost, light-weight, multi-spectral, multi-channel imaging system to handle the environment and see under difficult marine conditions. The system and its implemented detecting and tracking technologies should be organic to the maritime homeland security community for search and rescue, fisheries, defense, and law enforcement. It is tailored for airborne and ship based platforms to detect, track and monitor suspected objects (such as semi-submerged targets like marine mammals, vessels in distress, and drug smugglers). In this system, automated detection and tracking technology is used to detect, classify and localize potential threats or objects of interest within the imagery provided by the multi-spectral system. These algorithms process the sensor data in real time, thereby providing immediate feedback when features of interest have been detected. A supervised detection system based on Haar features and Cascade Classifiers is presented and results are provided on real data. The system is shown to be extendable and reusable for a variety of different applications.

  6. Computer-aided identification of novel protein targets of bisphenol A.

    PubMed

    Montes-Grajales, Diana; Olivero-Verbel, Jesus

    2013-10-01

    The xenoestrogen bisphenol A (2,2-bis-(p-hydroxyphenyl)-2-propane, BPA) is a known endocrine-disrupting chemical used in the fabrication of plastics, resins and flame retardants, that can be found throughout the environment and in numerous every day products. Human exposure to this chemical is extensive and generally occurs via oral route because it leaches from the food and beverage containers that contain it. Although most of the effects related to BPA exposure have been linked to the activation of the estrogen receptor (ER), the mechanisms of the interaction of BPA with protein targets different from ER are still unknown. Therefore, the objective of this work was to use a bioinformatics approach to identify possible new targets for BPA. Docking studies were performed between the optimized structure of BPA and 271 proteins related to different biochemical processes, as selected by text-mining. Refinement docking experiments and conformational analyses were carried out using LigandScout 3.0 for the proteins selected through the affinity ranking (lower than -8.0kcal/mol). Several proteins including ERR gamma (-9.9kcal/mol), and dual specificity protein kinases CLK-4 (-9.5kcal/mol), CLK-1 (-9.1kcal/mol) and CLK-2 (-9.0kcal/mol) presented great in silico binding affinities for BPA. The interactions between those proteins and BPA were mostly hydrophobic with the presence of some hydrogen bonds formed by leucine and asparagine residues. Therefore, this study suggests that this endocrine disruptor may have other targets different from the ER. PMID:23973438

  7. Conformational characterization of the intrinsically disordered protein Chibby: Interplay between structural elements in target recognition.

    PubMed

    Killoran, Ryan C; Sowole, Modupeola A; Halim, Mohammad A; Konermann, Lars; Choy, Wing-Yiu

    2016-08-01

    The protein Chibby (Cby) is an antagonist of the Wnt signaling pathway, where it inhibits the binding between the transcriptional coactivator β-catenin and the Tcf/Lef transcription factors. The 126 residue Cby is partially disordered; its N-terminal half is unstructured while its C-terminal half comprises a coiled-coil domain. Previous structural analyses of Cby using NMR spectroscopy suffered from severe line broadening for residues within the protein's C-terminal half, hindering detailed characterization of the coiled-coil domain. Here, we use hydrogen/deuterium exchange-mass spectrometry (HDX-MS) to examine Cby's C-terminal half. Results reveal that Cby is divided into three structural elements: a disordered N-terminal half, a coiled-coil domain, and a C-terminal unstructured extension consisting of the last ∼ 25 residues (which we term C-terminal extension). A series of truncation constructs were designed to assess the roles of individual structural elements in protein stability and Cby binding to TC-1, a positive regulator of the Wnt signaling pathway. CD and NMR data show that Cby maintains coiled-coil structure upon deletion of either disordered region. NMR and ITC binding experiments between Cby and TC-1 illustrate that the interaction is retained upon deletion of either Cby's N-terminal half or its C-terminal extension. Intriguingly, Cby's C-terminal half alone binds to TC-1 with significantly greater affinity compared to full-length Cby, implying that target binding of the coiled-coil domain is affected by the flanking disordered regions. PMID:27082063

  8. Image-aided Suicide Gene Therapy Utilizing Multifunctional hTERT-targeting Adenovirus for Clinical Translation in Hepatocellular Carcinoma

    PubMed Central

    Kim, Yun-Hee; Kim, Kyung Tae; Lee, Sang-Jin; Hong, Seung-Hee; Moon, Ju Young; Yoon, Eun Kyung; Kim, Sukyoung; Kim, Eun Ok; Kang, Se Hun; Kim, Seok Ki; Choi, Sun Il; Goh, Sung Ho; Kim, Daehong; Lee, Seong-Wook; Ju, Mi Ha; Jeong, Jin Sook; Kim, In-Hoo

    2016-01-01

    Trans-splicing ribozyme enables to sense and reprogram target RNA into therapeutic transgene and thereby becomes a good sensing device for detection of cancer cells, judging from transgene expression. Previously we proposed PEPCK-Rz-HSVtk (PRT), hTERT targeting trans-splicing ribozyme (Rz) driven by liver-specific promoter phosphoenolpyruvate carboxykinase (PEPCK) with downstream suicide gene, herpes simplex virus thymidine kinase (HSVtk) for hepatocellular carcinoma (HCC) gene therapy. Here, we describe success of a re-engineered adenoviral vector harboring PRT in obtaining greater antitumor activity with less off-target effect for clinical application as a theranostics. We introduced liver-selective apolipoprotein E (ApoE) enhancer to the distal region of PRT unit to augment activity and liver selectivity of PEPCK promoter, and achieved better transduction into liver cancer cells by replacement of serotype 35 fiber knob on additional E4orf1-4 deletion of E1&E3-deleted serotype 5 back bone. We demonstrated that our refined adenovirus harboring PEPCK/ApoE-Rz-HSVtk (Ad-PRT-E) achieved great anti-tumor efficacy and improved ability to specifically target HCC without damaging normal hepatocytes. We also showed noninvasive imaging modalities were successfully employed to monitor both how well a therapeutic gene (HSVtk) was expressed inside tumor and how effectively a gene therapy took an action in terms of tumor growth. Collectively, this study suggests that the advanced therapeutic adenoviruses Ad-PRT-E and its image-aided evaluation system may lead to the powerful strategy for successful clinical translation and the development of clinical protocols for HCC therapy. PMID:26909111

  9. AID-targeting and hypermutation of non-immunoglobulin genes does not correlate with proximity to immunoglobulin genes in germinal center B cells.

    PubMed

    Gramlich, Hillary Selle; Reisbig, Tara; Schatz, David G

    2012-01-01

    Upon activation, B cells divide, form a germinal center, and express the activation induced deaminase (AID), an enzyme that triggers somatic hypermutation of the variable regions of immunoglobulin (Ig) loci. Recent evidence indicates that at least 25% of expressed genes in germinal center B cells are mutated or deaminated by AID. One of the most deaminated genes, c-Myc, frequently appears as a translocation partner with the Ig heavy chain gene (Igh) in mouse plasmacytomas and human Burkitt's lymphomas. This indicates that the two genes or their double-strand break ends come into close proximity at a biologically relevant frequency. However, the proximity of c-Myc and Igh has never been measured in germinal center B cells, where many such translocations are thought to occur. We hypothesized that in germinal center B cells, not only is c-Myc near Igh, but other mutating non-Ig genes are deaminated by AID because they are near Ig genes, the primary targets of AID. We tested this "collateral damage" model using 3D-fluorescence in situ hybridization (3D-FISH) to measure the distance from non-Ig genes to Ig genes in germinal center B cells. We also made mice transgenic for human MYC and measured expression and mutation of the transgenes. We found that there is no correlation between proximity to Ig genes and levels of AID targeting or gene mutation, and that c-Myc was not closer to Igh than were other non-Ig genes. In addition, the human MYC transgenes did not accumulate mutations and were not deaminated by AID. We conclude that proximity to Ig loci is unlikely to be a major determinant of AID targeting or mutation of non-Ig genes, and that the MYC transgenes are either missing important regulatory elements that allow mutation or are unable to mutate because their new nuclear position is not conducive to AID deamination.

  10. Identification and analysis of potential targets in Streptococcus sanguinis using computer aided protein data analysis

    PubMed Central

    Chowdhury, Md Rabiul Hossain; Bhuiyan, Md IqbalKaiser; Saha, Ayan; Mosleh, Ivan MHAI; Mondol, Sobuj; Ahmed, C M Sabbir

    2014-01-01

    Purpose Streptococcus sanguinis is a Gram-positive, facultative aerobic bacterium that is a member of the viridans streptococcus group. It is found in human mouths in dental plaque, which accounts for both dental cavities and bacterial endocarditis, and which entails a mortality rate of 25%. Although a range of remedial mediators have been found to control this organism, the effectiveness of agents such as penicillin, amoxicillin, trimethoprim–sulfamethoxazole, and erythromycin, was observed. The emphasis of this investigation was on finding substitute and efficient remedial approaches for the total destruction of this bacterium. Materials and methods In this computational study, various databases and online software were used to ascertain some specific targets of S. sanguinis. Particularly, the Kyoto Encyclopedia of Genes and Genomes databases were applied to determine human nonhomologous proteins, as well as the metabolic pathways involved with those proteins. Different software such as Phyre2, CastP, DoGSiteScorer, the Protein Function Predictor server, and STRING were utilized to evaluate the probable active drug binding site with its known function and protein–protein interaction. Results In this study, among 218 essential proteins of this pathogenic bacterium, 81 nonhomologous proteins were accrued, and 15 proteins that are unique in several metabolic pathways of S. sanguinis were isolated through metabolic pathway analysis. Furthermore, four essentially membrane-bound unique proteins that are involved in distinct metabolic pathways were revealed by this research. Active sites and druggable pockets of these selected proteins were investigated with bioinformatic techniques. In addition, this study also mentions the activity of those proteins, as well as their interactions with the other proteins. Conclusion Our findings helped to identify the type of protein to be considered as an efficient drug target. This study will pave the way for researchers to

  11. Associating Drugs, Targets and Clinical Outcomes into an Integrated Network Affords a New Platform for Computer-Aided Drug Repurposing

    PubMed Central

    Oprea, Tudor I.; Nielsen, Sonny Kim; Ursu, Oleg; Yang, Jeremy J.; Taboureau, Olivier; Mathias, Stephen L.; Kouskoumvekaki, lrene; Sklar, Larry A.; Bologa, Cristian G.

    2012-01-01

    Finding new uses for old drugs is a strategy embraced by the pharmaceutical industry, with increasing participation from the academic sector. Drug repurposing efforts focus on identifying novel modes of action, but not in a systematic manner. With intensive data mining and curation, we aim to apply bio- and cheminformatics tools using the DRUGS database, containing 3,837 unique small molecules annotated on 1,750 proteins. These are likely to serve as drug targets and antitargets (i.e., associated with side effects, SE). The academic community, the pharmaceutical sector and clinicians alike could benefit from an integrated, semantic-web compliant computer-aided drug repurposing (CADR) effort, one that would enable deep data mining of associations between approved drugs (D), targets (T), clinical outcomes (CO) and SE. We report preliminary results from text mining and multivariate statistics, based on 7,684 approved drug labels, ADL (Dailymed) via text mining. From the ADL corresponding to 988 unique drugs, the “adverse reactions” section was mapped onto 174 SE, then clustered via principal component analysis into a 5x5 self-organizing map that was integrated into a Cytoscape network of SE-D-T-CO. This type of data can be used to streamline drug repurposing and may result in novel insights that can lead to the identification of novel drug actions. PMID:22287994

  12. Targeted therapies to treat Non-AIDS Defining Cancers in patients with HIV on HAART therapy – treatment considerations and research outlook

    PubMed Central

    Deeken, John F.; Pantanowitz, Liron; Dezube, Bruce J.

    2012-01-01

    Purpose of review Highly active antiretroviral therapy (HAART) has led to a dramatic improvement in the prognosis of patients diagnosed with HIV and AIDS. This includes a significant decline in the rates of AIDS-related cancers, including Kaposi Sarcoma and Non-Hodgkin's Lymphoma. Unfortunately, rates of Non-AIDS Defining Cancers (NADCs) are on the rise, and now exceed the rates of AIDS-related cancers in patients with HIV. Treating NADCs in patients who are on HAART therapy is an open and complicated clinical question. Recent findings Newer targeted therapies are now available to treat cancers which were historically refractory to traditional cytotoxic chemotherapy. HAART agents are notorious for causing drug-drug interactions. The co-administration of targeted chemotherapies with HAART could well impede the efficacy or increase the toxicity of these targeted therapies. Unfortunately little is known about possible drug-drug interactions because HIV patients are typically excluded from clinical trials. Summary We highlight what is known about how and why HAART agents can affect drug metabolism. We then present the clinical and pharmacological data for nine recently approved targeted therapies – imatinib, dasatinib, nilotinib, erlotinib, sunitinib, lapatinib, bortezomib, sorafenib, and temsirolimus. We conclude with considerations on how to use these new agents to treat NADCs, and discuss a future research agenda to better understand and predict potential HAART-targeted therapy interactions. PMID:19606034

  13. Middle East respiratory syndrome coronavirus: transmission, virology and therapeutic targeting to aid in outbreak control

    PubMed Central

    Durai, Prasannavenkatesh; Batool, Maria; Shah, Masaud; Choi, Sangdun

    2015-01-01

    Middle East respiratory syndrome coronavirus (MERS-CoV) causes high fever, cough, acute respiratory tract infection and multiorgan dysfunction that may eventually lead to the death of the infected individuals. MERS-CoV is thought to be transmitted to humans through dromedary camels. The occurrence of the virus was first reported in the Middle East and it subsequently spread to several parts of the world. Since 2012, about 1368 infections, including ~487 deaths, have been reported worldwide. Notably, the recent human-to-human ‘superspreading' of MERS-CoV in hospitals in South Korea has raised a major global health concern. The fatality rate in MERS-CoV infection is four times higher compared with that of the closely related severe acute respiratory syndrome coronavirus infection. Currently, no drug has been clinically approved to control MERS-CoV infection. In this study, we highlight the potential drug targets that can be used to develop anti-MERS-CoV therapeutics. PMID:26315600

  14. Using queuing models to aid design and guide research effort for multimodality buried target detection systems

    NASA Astrophysics Data System (ADS)

    Malof, Jordan M.; Collins, Leslie M.

    2016-05-01

    Many remote sensing modalities have been developed for buried target detection (BTD), each one offering relative advantages over the others. There has been interest in combining several modalities into a single BTD system that benefits from the advantages of each constituent sensor. Recently an approach was developed, called multi-state management (MSM), that aims to achieve this goal by separating BTD system operation into discrete states, each with different sensor activity and system velocity. Additionally, a modeling approach, called Q-MSM, was developed to quickly analyze multi-modality BTD systems operating with MSM. This work extends previous work by demonstrating how Q-MSM modeling can be used to design BTD systems operating with MSM, and to guide research to yield the most performance benefits. In this work an MSM system is considered that combines a forward-looking infrared (FLIR) camera and a ground penetrating radar (GPR). Experiments are conducted using a dataset of real, field-collected, data which demonstrates how the Q-MSM model can be used to evaluate performance benefits of altering, or improving via research investment, various characteristics of the GPR and FLIR systems. Q-MSM permits fast analysis that can determine where system improvements will have the greatest impact, and can therefore help guide BTD research.

  15. Effects of Response Bias and Judgment Framing on Operator Use of an Automated Aid in a Target Detection Task

    ERIC Educational Resources Information Center

    Rice, Stephen; McCarley, Jason S.

    2011-01-01

    Automated diagnostic aids prone to false alarms often produce poorer human performance in signal detection tasks than equally reliable miss-prone aids. However, it is not yet clear whether this is attributable to differences in the perceptual salience of the automated aids' misses and false alarms or is the result of inherent differences in…

  16. Automated pattern recognition to support geological mapping and exploration target generation - A case study from southern Namibia

    NASA Astrophysics Data System (ADS)

    Eberle, Detlef; Hutchins, David; Das, Sonali; Majumdar, Anandamayee; Paasche, Hendrik

    2015-06-01

    to the result obtained from unsupervised fuzzy clustering. Furthermore, a comparison of the aposterior probability of class assignment with the trustworthiness values provided by fuzzy clustering also indicates only slight differences. These observed differences can be explained by the exponential class probability term which tends to deliver either fairly high or low probability values. The methodology and results presented here demonstrate that automated objective pattern recognition can essentially contribute to geological mapping of large study areas and mineral exploration target generation. This methodology is considered well suited to a number of African countries whose large territories have recently been covered by high resolution airborne geophysical data, but where existing geological mapping is poor, incomplete or outdated.

  17. Mutations, kataegis, and translocations in B lymphocytes: towards a mechanistic understanding of AID promiscuous activity

    PubMed Central

    Casellas, Rafael; Basu, Uttiya; Yewdell, William T.; Chaudhuri, Jayanta; Robbiani, Davide F.; Di Noia, Javier M.

    2016-01-01

    As B cells engage in the immune response they express the deaminase AID to initiate the hypermutation and recombination of immunoglobulin genes, which are crucial processes for the efficient recognition and disposal of pathogens, However, AID must be tightly controlled in B cells to minimize off-targeting mutations, which can drive chromosomal translocations and the development of B cell malignancies, such as lymphomas. Recent genomic and biochemical analyses have begun to unravel the crucial question of how AID-mediated deamination is targeted outside immunoglobulin genes. Here, we discuss the transcriptional and topological features that are emerging as key drivers of AID promiscuous activity. PMID:26898111

  18. ERP Correlates of Target-Distracter Differentiation in Repeated Runs of a Continuous Recognition Task with Emotional and Neutral Faces

    ERIC Educational Resources Information Center

    Treese, Anne-Cecile; Johansson, Mikael; Lindgren, Magnus

    2010-01-01

    The emotional salience of faces has previously been shown to induce memory distortions in recognition memory tasks. This event-related potential (ERP) study used repeated runs of a continuous recognition task with emotional and neutral faces to investigate emotion-induced memory distortions. In the second and third runs, participants made more…

  19. Adoption of workplaces and reach of employees for a multi-faceted intervention targeting low back pain among nurses’ aides

    PubMed Central

    2014-01-01

    Background Workplace adoption and reach of health promotion are important, but generally poorly reported. The aim of this study is therefore to evaluate the adoption of workplaces (organizational level) and reach of employees (individual level) of a multi-faceted workplace health promotion and work environment intervention targeting low back pain among nurses’ aides in elderly care. Methods Percentage of adopters was calculated among eligible workplaces and differences between adopters and non-adopters were evaluated through workplace registrations and manager questionnaires from all eligible workplaces. From the adopted workplaces reach was calculated among eligible employees as the percentage who responded on a questionnaire. Responders were compared with non-responders using data from company registrations. Among responders, comparisons based on questionnaire data were performed between those consenting to participate in the intervention (consenters) and those not consenting to participate in the intervention (non-consenters). Comparisons were done using Student's t-test for the continuous variables, Fisher's exact test for dichotomous variables and the Pearson’s chi2 for categorical variables. Moreover odds ratios for non-responding and non-consenting were investigated with binary logistic regression analyses. Results The project was adopted by 44% of the offered workplaces. The main differences between adopters and non-adopters were that workplaces adopting the intervention had a more stable organization as well as a management with positive beliefs of the intervention’s potential benefits. Of eligible employees, 71% responded on the questionnaire and 57% consented to participate. Non-responders and non-consenters did not differ from the responders and consenters on demographic factors and health. However, more non-responders and non-consenters were low skilled, worked less than 30 hours pr. week, and worked evening and nightshift compared to responders

  20. Sensory Aids for the Blind.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC. Committee on Prosthetics Research and Development.

    The problems of providing sensory aids for the blind are presented and a report on the present status of aids discusses direct translation and recognition reading machines as well as mobility aids. Aspects of required research considered are the following: assessment of needs; vision, audition, taction, and multimodal communication; reading aids,…

  1. Interleukin-4 receptor expression on AIDS-associated Kaposi's sarcoma cells and their targeting by a chimeric protein comprised of circularly permuted interleukin-4 and Pseudomonas exotoxin.

    PubMed Central

    Husain, S. R.; Gill, P.; Kreitman, R. J.; Pastan, I.; Puri, R. K.

    1997-01-01

    BACKGROUND: AIDS-associated Kaposi's sarcoma (AIDS-KS) represents one of the most common malignancies associated with human immunodeficiency virus infection. To target effective therapeutic agents to AIDS-KS, we have identified a new target in the form of interleukin-4 receptors (IL-4R). MATERIALS AND METHODS: The expression of IL-4R on AIDS-KS cells and their subunit structure was determined by radioligand receptor binding, cross-linking and Northern and RT-PCR analyses. The in vitro effect of IL-4 and recombinant fusion protein made up of circularly permuted IL-4 and a mutated form of Pseudomonas exotoxin, IL-4(38-37)-PE38KDEL, was examined by clonogenic and protein synthesis inhibition assays. RESULTS: Five AIDS-KS cell lines expressed high-affinity IL-4R with a Kd of 23.5-219 pM. IL-4 appeared to cross-link to one major protein corresponding to 140 kDa and a broad band corresponding to 60-70 kDa. Both cross-linked proteins were immunoprecipitated with an antibody to human IL-4R beta chain. AIDS-KS cells exhibited IL-4R beta-specific mRNA. IL-4 caused a modest inhibition (31-34%) of colony formation in two AIDS-KS cell lines tested. IL-4(38-37)-PE38KDEL was found to be highly effective in inhibiting the protein synthesis in all five AIDS-KS examined. The IC50 ranged from 32 to 1225 pM. The cytotoxic action of IL-4 toxin was blocked by an excess of IL-4, exhibiting the specificity of IL-4(38-37)-PE38KDEL. The cytotoxicity of IL-4 toxin observed by a clonogenic assay corroborated well with the IC50 obtained by protein synthesis inhibition assay. Normal human endothelial cells expressed a negligible number of IL-4R (< 50 sites/cell) and were less sensitive or not sensitive to IL-4(38-37)-PE38KDEL. CONCLUSION: The presence of a new plasma membrane protein in the form of IL-4R on AIDS-KS cells may be targeted by IL-4(38-37)-PE38KDEL for its potential implication in the treatment of AIDS-KS. Images FIG. 3 FIG. 4 FIG. 6 PMID:9205948

  2. Effects of response bias and judgment framing on operator use of an automated aid in a target detection task.

    PubMed

    Rice, Stephen; McCarley, Jason S

    2011-12-01

    Automated diagnostic aids prone to false alarms often produce poorer human performance in signal detection tasks than equally reliable miss-prone aids. However, it is not yet clear whether this is attributable to differences in the perceptual salience of the automated aids' misses and false alarms or is the result of inherent differences in operators' cognitive responses to different forms of automation error. The present experiments therefore examined the effects of automation false alarms and misses on human performance under conditions in which the different forms of error were matched in their perceptual characteristics. Young adult participants performed a simulated baggage x-ray screening task while assisted by an automated diagnostic aid. Judgments from the aid were rendered as text messages presented at the onset of each trial, and every trial was followed by a second text message providing response feedback. Thus, misses and false alarms from the aid were matched for their perceptual salience. Experiment 1 found that even under these conditions, false alarms from the aid produced poorer human performance and engendered lower automation use than misses from the aid. Experiment 2, however, found that the asymmetry between misses and false alarms was reduced when the aid's false alarms were framed as neutral messages rather than explicit misjudgments. Results suggest that automation false alarms and misses differ in their inherent cognitive salience and imply that changes in diagnosis framing may allow designers to encourage better use of imperfectly reliable automated aids.

  3. Identification of the RNA recognition element of the RBPMS family of RNA-binding proteins and their transcriptome-wide mRNA targets.

    PubMed

    Farazi, Thalia A; Leonhardt, Carl S; Mukherjee, Neelanjan; Mihailovic, Aleksandra; Li, Song; Max, Klaas E A; Meyer, Cindy; Yamaji, Masashi; Cekan, Pavol; Jacobs, Nicholas C; Gerstberger, Stefanie; Bognanni, Claudia; Larsson, Erik; Ohler, Uwe; Tuschl, Thomas

    2014-07-01

    Recent studies implicated the RNA-binding protein with multiple splicing (RBPMS) family of proteins in oocyte, retinal ganglion cell, heart, and gastrointestinal smooth muscle development. These RNA-binding proteins contain a single RNA recognition motif (RRM), and their targets and molecular function have not yet been identified. We defined transcriptome-wide RNA targets using photoactivatable-ribonucleoside-enhanced crosslinking and immunoprecipitation (PAR-CLIP) in HEK293 cells, revealing exonic mature and intronic pre-mRNA binding sites, in agreement with the nuclear and cytoplasmic localization of the proteins. Computational and biochemical approaches defined the RNA recognition element (RRE) as a tandem CAC trinucleotide motif separated by a variable spacer region. Similar to other mRNA-binding proteins, RBPMS family of proteins relocalized to cytoplasmic stress granules under oxidative stress conditions suggestive of a support function for mRNA localization in large and/or multinucleated cells where it is preferentially expressed.

  4. Dynamic Conformational Change Regulates the Protein-DNA Recognition: An Investigation on Binding of a Y-Family Polymerase to Its Target DNA

    PubMed Central

    Chu, Xiakun; Liu, Fei; Maxwell, Brian A.; Wang, Yong; Suo, Zucai; Wang, Haijun; Han, Wei; Wang, Jin

    2014-01-01

    Protein-DNA recognition is a central biological process that governs the life of cells. A protein will often undergo a conformational transition to form the functional complex with its target DNA. The protein conformational dynamics are expected to contribute to the stability and specificity of DNA recognition and therefore may control the functional activity of the protein-DNA complex. Understanding how the conformational dynamics influences the protein-DNA recognition is still challenging. Here, we developed a two-basin structure-based model to explore functional dynamics in Sulfolobus solfataricus DNA Y-family polymerase IV (DPO4) during its binding to DNA. With explicit consideration of non-specific and specific interactions between DPO4 and DNA, we found that DPO4-DNA recognition is comprised of first 3D diffusion, then a short-range adjustment sliding on DNA and finally specific binding. Interestingly, we found that DPO4 is under a conformational equilibrium between multiple states during the binding process and the distributions of the conformations vary at different binding stages. By modulating the strength of the electrostatic interactions, the flexibility of the linker, and the conformational dynamics in DPO4, we drew a clear picture on how DPO4 dynamically regulates the DNA recognition. We argue that the unique features of flexibility and conformational dynamics in DPO4-DNA recognition have direct implications for low-fidelity translesion DNA synthesis, most of which is found to be accomplished by the Y-family DNA polymerases. Our results help complete the description of the DNA synthesis process for the Y-family polymerases. Furthermore, the methods developed here can be widely applied for future investigations on how various proteins recognize and bind specific DNA substrates. PMID:25188490

  5. Real-time and offline performance of pattern recognition myoelectric control using a generic electrode grid with targeted muscle reinnervation patients.

    PubMed

    Tkach, Dennis C; Young, Aaron J; Smith, Lauren H; Rouse, Elliott J; Hargrove, Levi J

    2014-07-01

    Targeted muscle reinnervation (TMR) is a surgical technique that creates myoelectric prosthesis control sites for high-level amputees. The electromyographic (EMG) signal patterns provided by the reinnervated muscles are well-suited for pattern recognition control. Pattern recognition allows for control of a greater number of degrees of freedom (DOF) than the conventional, EMG amplitude-based approach. Previous pattern recognition studies have shown benefit in placing electrodes directly over the reinnervated muscles. Localizing the optimal TMR locations is inconvenient and time consuming. In this contribution, we demonstrate that a clinically practical grid arrangement of electrodes yields real-time control performance that is equivalent to, or better than, the site-specific electrode placement for simultaneous control of multiple DOFs using pattern recognition. Additional findings indicate that grid-like electrode arrangement yields significantly lower classification errors for classifiers with a large number of movement classes ( > 9). These findings suggest that a grid electrode arrangement can be effectively used to control a multi-DOF upper limb prosthesis while reducing the time and effort associated with fitting the prosthesis due to clinical localization of control sites on amputee patients.

  6. HIV/AIDS and Alcohol

    MedlinePlus

    ... Psychiatric Disorders Other Substance Abuse HIV/AIDS HIV/AIDS Human immunodeficiency virus (HIV) targets the body’s immune ... and often leads to acquired immune deficiency syndrome (AIDS). Each year in the United States, between 55, ...

  7. Sequence-specific recognition of double-stranded DNA with molecular beacon with the aid of Ag(+) under neutral pH environment.

    PubMed

    Xiao, Zhiyou; Guo, Xiaoting; Ling, Liansheng

    2013-05-01

    A sensitive fluorescent sensor for sequence-specific recognition of dsDNA was established with a molecular beacon (MB) based upon the formation of parallel triplex DNA in the presence of Ag(+) under neutral pH environment.

  8. Pre-Experimental Familiarization Increases Hippocampal Activity for Both Targets and Lures in Recognition Memory: An fMRI Study

    ERIC Educational Resources Information Center

    de Zubicaray, Greig I.; McMahon, Katie L.; Hayward, Lydia; Dunn, John C.

    2011-01-01

    In the present study, items pre-exposed in a familiarization series were included in a list discrimination task to manipulate memory strength. At test, participants were required to discriminate strong targets and strong lures from weak targets and new lures. This resulted in a concordant pattern of increased "old" responses to strong targets and…

  9. Target deconvolution strategies in drug discovery.

    PubMed

    Terstappen, Georg C; Schlüpen, Christina; Raggiaschi, Roberto; Gaviraghi, Giovanni

    2007-11-01

    Recognition of some of the limitations of target-based drug discovery has recently led to the renaissance of a more holistic approach in which complex biological systems are investigated for phenotypic changes upon exposure to small molecules. The subsequent identification of the molecular targets that underlie an observed phenotypic response--termed target deconvolution--is an important aspect of current drug discovery, as knowledge of the molecular targets will greatly aid drug development. Here, the broad panel of experimental strategies that can be applied to target deconvolution is critically reviewed.

  10. An Exquisitely Specific PDZ/Target Recognition Revealed by the Structure of INAD PDZ3 in Complex with TRP Channel Tail.

    PubMed

    Ye, Fei; Liu, Wei; Shang, Yuan; Zhang, Mingjie

    2016-03-01

    The vast majority of PDZ domains are known to bind to a few C-terminal tail residues of target proteins with modest binding affinities and specificities. Such promiscuous PDZ/target interactions are not compatible with highly specific physiological functions of PDZ domain proteins and their targets. Here, we report an unexpected PDZ/target binding occurring between the scaffold protein inactivation no afterpotential D (INAD) and transient receptor potential (TRP) channel in Drosophila photoreceptors. The C-terminal 15 residues of TRP are required for the specific interaction with INAD PDZ3. The INAD PDZ3/TRP peptide complex structure reveals that only the extreme C-terminal Leu of TRP binds to the canonical αB/βB groove of INAD PDZ3. The rest of the TRP peptide, by forming a β hairpin structure, binds to a surface away from the αB/βB groove of PDZ3 and contributes to the majority of the binding energy. Thus, the INAD PDZ3/TRP channel interaction is exquisitely specific and represents a new mode of PDZ/target recognitions.

  11. Automatic parameter adjustment of difference of Gaussian (DoG) filter to improve OT-MACH filter performance for target recognition applications

    NASA Astrophysics Data System (ADS)

    Alkandri, Ahmad; Gardezi, Akber; Bangalore, Nagachetan; Birch, Philip; Young, Rupert; Chatwin, Chris

    2011-11-01

    A wavelet-modified frequency domain Optimal Trade-off Maximum Average Correlation Height (OT-MACH) filter has been trained using 3D CAD models and tested on real target images acquired from a Forward Looking Infra Red (FLIR) sensor. The OT-MACH filter can be used to detect and discriminate predefined targets from a cluttered background. The FLIR sensor extends the filter's ability by increasing the range of detection by exploiting the heat signature differences between the target and the background. A Difference of Gaussians (DoG) based wavelet filter has been use to improve the OT-MACH filter discrimination ability and distortion tolerance. Choosing the right standard deviation values of the two Gaussians comprising the filter is critical. In this paper we present a new technique for auto adjustment of the DoG filter parameters driven by the expected target size. Tests were carried on images acquired by the Apache AH-64 helicopter mounted FLIR sensor, results showing an overall improvement in the recognition of target objects present within the IR images.

  12. Targeting Pathogenic Post-Ischemic Self-Recognition by Natural IgM to Protect Against Post-Transplant Cardiac Reperfusion Injury

    PubMed Central

    Atkinson, Carl; Qiao, Fei; Yang, Xiaofeng; Zhu, Peng; Reaves, Nicholas; Kulik, Liudmila; Goddard, Martin; Holers, V. Michael; Tomlinson, Stephen

    2015-01-01

    Background Natural IgM antibodies represent a class of innate pattern recognition receptors that recognize danger associated molecular patterns expressed on stressed or dying cells. They play important roles in tissue homeostasis by disposing of pre-necrotic cells and suppressing inflammation. However, ischemic insult leads to a pathogenic level of IgM binding and complement activation, resulting in inflammation and injury. We investigate the role of self-reactive IgM in the unique setting of transplantation, where the donor organ undergoes both cold and warm ischemia, and global ischemic insult. Methods and Results By transplanting hearts from wild-type donor mice into antibody-deficient mice reconstituted with specific self-reactive IgM mAbs, we identified neoepitopes expressed post-transplant, and demonstrated a key role for IgM recognition of these epitopes in graft injury. With this information, we developed and characterized a therapeutic strategy that exploited the post-ischemia recognition system of natural antibodies. Based on neoepitope identification, we constructed an anti-annexin-IV single chain antibody (scFv) and an scFv linked to Crry, an inhibitor of C3 activation (scFv-Crry). In an allograft transplant model, in which recipients contain a full natural antibody repertoire, both constructs blocked graft IgM binding and complement activation, and significantly reduced graft inflammation and injury. Furthermore, scFv-Crry specifically targeted to the transplanted heart and, unlike complement deficiency, did not affect immunity to infection, an important consideration for immunosuppressed transplant recipients. Conclusions We identified pathophysiologically important epitopes expressed within the heart post-transplant, and describe a novel translatable strategy for targeted complement inhibition that has several advantages over currently available approaches. PMID:25825397

  13. Implant-Assisted Intrathecal Magnetic Drug Targeting to Aid in Therapeutic Nanoparticle Localization for Potential Treatment of Central Nervous System Disorders.

    PubMed

    Lueshen, Eric; Venugopal, Indu; Soni, Tejen; Alaraj, Ali; Linninger, Andreas

    2015-02-01

    There is an ongoing struggle to develop efficient drug delivery and targeting methods within the central nervous system. One technique known as intrathecal drug delivery, involves direct drug infusion into the spinal canal and has become standard practice for treating many central nervous system diseases due to reduced systemic toxicity from the drug bypassing the blood-brain barrier. Although intrathecal drug delivery boasts the advantage of reduced systemic toxicity compared to oral and intravenous drug delivery techniques, current intrathecal delivery protocols lack a means of sufficient drug targeting at specific locations of interest within the central nervous system. We previously proposed the method of intrathecal magnetic drug targeting in order to overcome the limited targeting capabilities of standard intrathecal drug delivery protocols, while simultaneously reducing the systemic toxicity as well as the amount of drug required to produce a therapeutic effect. Building off of our previous work, this paper presents the concept of implant-assisted intrathecal magnetic drug targeting. Ferritic stainless steel implants were incorporated within the subarachnoid space of our in vitro human spine model, and the targeting magnet was placed at a physiological distance away from the model and implant to mimic the distance between the epidermis and spinal canal. Computer simulations were performed to optimize implant design for generating high gradient magnetic fields and to study how these fields may aid in therapeutic nanoparticle localization. Experiments aiming to determine the effects of different magnetically-susceptible implants placed within an external magnetic field on the targeting efficiency of gold-coated magnetite nanoparticles were then performed on our in vitro human spine model. Our results indicate that implant-assisted intrathecal magnetic drug targeting is an excellent supplementary technique to further enhance the targeting capabilities of our

  14. Writing with Voice: An Investigation of the Use of a Voice Recognition System as a Writing Aid for a Man with Aphasia

    ERIC Educational Resources Information Center

    Bruce, Carolyn; Edmundson, Anne; Coleman, Michael

    2003-01-01

    Background: People with aphasia may experience difficulties that prevent them from demonstrating in writing what they know and can produce orally. Voice recognition systems that allow the user to speak into a microphone and see their words appear on a computer screen have the potential to assist written communication. Aim: This study investigated…

  15. Bipartite recognition of target RNAs activates DNA cleavage by the Type III-B CRISPR–Cas system

    PubMed Central

    Elmore, Joshua R.; Sheppard, Nolan F.; Ramia, Nancy; Deighan, Trace; Li, Hong; Terns, Rebecca M.; Terns, Michael P.

    2016-01-01

    CRISPR–Cas systems eliminate nucleic acid invaders in bacteria and archaea. The effector complex of the Type III-B Cmr system cleaves invader RNAs recognized by the CRISPR RNA (crRNA ) of the complex. Here we show that invader RNAs also activate the Cmr complex to cleave DNA. As has been observed for other Type III systems, Cmr eliminates plasmid invaders in Pyrococcus furiosus by a mechanism that depends on transcription of the crRNA target sequence within the plasmid. Notably, we found that the target RNA per se induces DNA cleavage by the Cmr complex in vitro. DNA cleavage activity does not depend on cleavage of the target RNA but notably does require the presence of a short sequence adjacent to the target sequence within the activating target RNA (rPAM [RNA protospacer-adjacent motif]). The activated complex does not require a target sequence (or a PAM) in the DNA substrate. Plasmid elimination by the P. furiosus Cmr system also does not require the Csx1 (CRISPR-associated Rossman fold [CARF] superfamily) protein. Plasmid silencing depends on the HD nuclease and Palm domains of the Cmr2 (Cas10 superfamily) protein. The results establish the Cmr complex as a novel DNA nuclease activated by invader RNAs containing a crRNA target sequence and a rPAM. PMID:26848045

  16. Divine targets: youth at the centre of Catholic and Pentecostal responses to HIV and AIDS in Brazil

    PubMed Central

    Muñoz-Laboy, Miguel; Murray, Laura; Wittlin, Natalie; Parker, Richard

    2011-01-01

    This study explored the focus on youth in Catholic and Evangelical Pentecostal discussions about and responses to HIV and AIDS in Brazil. Key informant, oral history, and in-depth interviews revealed a disconnect between young people’s views of themselves as leaders in their religious institutions’ responses to HIV and other social problems and adult religious leaders’ views of youth as vulnerable and in need of being saved. Religious leaders presented young people as institutional commodities, emphasizing their symbolic value as signs of the health and future of their churches. We explore the unofficial exchange between religious institutions and young people, who benefited from the leadership opportunities and communities provided by their churches and youth groups.We discuss the political economy of youth in religious institutions’ responses to HIV and AIDS within the context of Brazil’s high levels of religious mobility as well as the broader, global commodification of spirituality and religion. PMID:21516533

  17. Insights into the Recognition, Binding and Reactivity of Catalytic Metallodrugs Targeting Stem Loop IIb of Hepatitis C IRES RNA

    PubMed Central

    Bradford, Seth S.; Ross, Martin James; Fidai, Insiya; Cowan, J. A.

    2014-01-01

    Complex Cu-GGHYrFK-amide (1-Cu) was previously reported as a novel metallotherapeutic that catalytically inactivates stem loop IIb of the Hepatitis C Virus (HCV) Internal Ribosomal Entry Site (IRES) RNA and demonstrates significant antiviral activity in a cellular HCV replicon assay. Herein are described additional studies focused on understanding the cleavage mechanism, as well as the relationship of catalyst configuration to structural recognition and site-selective cleavage of the structured RNA motif. These are advanced by use of a combination of MALDI-TOF mass spectrometry, melting temperature determination, and computational analysis to develop a structural model for binding and reactivity toward SLIIb of the IRES RNA. In addition, the binding, reactivity, and structural chemistry of the all d-amino acid form of this metallopeptide, complex 2-Cu, is reported and compared to complex 1-Cu. In vitro RNA binding and cleavage assays for complex 2-Cu show a KD of 76 ± 3 nM, and Michaelis-Menten parameters of kcat of 0.14 ± 0.01 min−1 and KM of 7.9 ± 1.2 µM, with a turnover number exceeding 40. In a luciferase-based cellular replicon assay Cu-GGhyrfk-amide shows activity similar to the parent peptide, complex 1-Cu, with IC50 of 1.9 ± 0.4 µM and cytotoxicity exceeding 100 µM. RT-PCR experiments confirm a significant reduction in HCV RNA levels in replicon assays for up to nine days when treated with complex 1-Cu in three day dosing increments. This study shows the influence that the α-carbon stereocenter has for this the new class of compounds, while detailed mass spectrometry and computational analysis provide new insights into the mechanisms of recognition, binding, and reactivity. PMID:24756921

  18. [Multi-Target Recognition of Internal and External Defects of Potato by Semi-Transmission Hyperspectral Imaging and Manifold Learning Algorithm].

    PubMed

    Huang, Tao; Li, Xiao-yu; Jin, Rui; Ku, Jing; Xu, Sen-miao; Xu, Meng-ling; Wu, Zhen-zhong; Kong, De-guo

    2015-04-01

    The present paper put forward a non-destructive detection method which combines semi-transmission hyperspectral imaging technology with manifold learning dimension reduction algorithm and least squares support vector machine (LSSVM) to recognize internal and external defects in potatoes simultaneously. Three hundred fifteen potatoes were bought in farmers market as research object, and semi-transmission hyperspectral image acquisition system was constructed to acquire the hyperspectral images of normal external defects (bud and green rind) and internal defect (hollow heart) potatoes. In order to conform to the actual production, defect part is randomly put right, side and back to the acquisition probe when the hyperspectral images of external defects potatoes are acquired. The average spectrums (390-1,040 nm) were extracted from the region of interests for spectral preprocessing. Then three kinds of manifold learning algorithm were respectively utilized to reduce the dimension of spectrum data, including supervised locally linear embedding (SLLE), locally linear embedding (LLE) and isometric mapping (ISOMAP), the low-dimensional data gotten by manifold learning algorithms is used as model input, Error Correcting Output Code (ECOC) and LSSVM were combined to develop the multi-target classification model. By comparing and analyzing results of the three models, we concluded that SLLE is the optimal manifold learning dimension reduction algorithm, and the SLLE-LSSVM model is determined to get the best recognition rate for recognizing internal and external defects potatoes. For test set data, the single recognition rate of normal, bud, green rind and hollow heart potato reached 96.83%, 86.96%, 86.96% and 95% respectively, and he hybrid recognition rate was 93.02%. The results indicate that combining the semi-transmission hyperspectral imaging technology with SLLE-LSSVM is a feasible qualitative analytical method which can simultaneously recognize the internal and

  19. Selective recognition and stabilization of new ligands targeting the potassium form of the human telomeric G-quadruplex DNA

    PubMed Central

    Lin, Yi-Hwa; Chuang, Show-Mei; Wu, Pei-Ching; Chen, Chun-Liang; Jeyachandran, Sivakamavalli; Lo, Shou-Chen; Huang, Hsu-Shan; Hou, Ming-Hon

    2016-01-01

    The development of a ligand that is capable of distinguishing among the wide variety of G-quadruplex structures and targeting telomeres to treat cancer is particularly challenging. In this study, the ability of two anthraquinone telomerase inhibitors (NSC749235 and NSC764638) to target telomeric G-quadruplex DNA was probed. We found that these ligands specifically target the potassium form of telomeric G-quadruplex DNA over the DNA counterpart. The characteristic interaction with the telomeric G-quadruplex DNA and the anticancer activities of these ligands were also explored. The results of this present work emphasize our understanding of the binding selectivity of anthraquinone derivatives to G-quadruplex DNA and assists in future drug development for G-quadruplex-specific ligands. PMID:27511133

  20. Selective recognition and stabilization of new ligands targeting the potassium form of the human telomeric G-quadruplex DNA

    NASA Astrophysics Data System (ADS)

    Lin, Yi-Hwa; Chuang, Show-Mei; Wu, Pei-Ching; Chen, Chun-Liang; Jeyachandran, Sivakamavalli; Lo, Shou-Chen; Huang, Hsu-Shan; Hou, Ming-Hon

    2016-08-01

    The development of a ligand that is capable of distinguishing among the wide variety of G-quadruplex structures and targeting telomeres to treat cancer is particularly challenging. In this study, the ability of two anthraquinone telomerase inhibitors (NSC749235 and NSC764638) to target telomeric G-quadruplex DNA was probed. We found that these ligands specifically target the potassium form of telomeric G-quadruplex DNA over the DNA counterpart. The characteristic interaction with the telomeric G-quadruplex DNA and the anticancer activities of these ligands were also explored. The results of this present work emphasize our understanding of the binding selectivity of anthraquinone derivatives to G-quadruplex DNA and assists in future drug development for G-quadruplex-specific ligands.

  1. miR-152 as a tumor suppressor microRNA: Target recognition and regulation in cancer

    PubMed Central

    LIU, XUEXIANG; LI, JINWAN; QIN, FENGXIAN; DAI, SHENGMING

    2016-01-01

    MicroRNAs (miRNAs or miRs) are endogenous translation repressors of protein-coding genes that act by binding to the 3′-untranslated region of their target genes, and may contribute to tumorigenesis by functioning as oncogenes or tumor suppressor genes. miR-152, a member of the miR-148/152 family, is aberrantly expressed in various diseases, including various types of cancer. A growing body of evidence has demonstrated that miR-152 may act as a tumor suppressor gene by regulating its target genes, which are associated with cell proliferation, migration and invasion in human cancer. In the present review, the gene structure and functions of miR-152 are discussed, and in particular, its regulatory mechanism, experimentally validated targets and tumor suppressor role in cancer, are highlighted. PMID:27313716

  2. [Recognition of the potential SF-1 binding sites by SiteGA method, their experimental verification and search for new SF-1 target genes].

    PubMed

    Klimova, N V; Levitskiĭ, V G; Ignat'eva, E V; Vasil'ev, G V; Kobzev, V F; Busygina, T V; Merkulova, T I; Kolchanov, N A

    2006-01-01

    The SF-1 (Steroidogenic Factor-1) is a transcription factor known as a key regulator of the steroidogenic gene expression. SF-1 is required for the development and functioning at all levels of the hypothalamic-pituitary-gonadal and adrenal axis. Also it plays an essential role in sex determination. SF-1 is a member of the nuclear receptor superfamily and it activates gene expression by binding to DNA in a monomeric form. Here, we report the results of potential SF-1 binding sites identification by using the SiteGA recognition method. The SiteGA method was implemented using a genetic algorithm (GA) involving a iterative discriminant analyses of local dinucleotide context characteristics. These characteristics were compiled not only over the core binding sites region but over its flanks as well. Developed SiteGA method is characterized by considerably better recognition accuracy when compared to that for the weight matrix method. The experimental tests demonstrated that 83% of the sites recognized by the SiteGA method in the regulatory regions of steroidogenic genes, indeed, interact with the SF-1 factor. We also estimated the density of predicted sites in regulatory region of genes, the members of different functional groups and developed the criterion to search for new SF-1 target genes in genome sequences.

  3. Innate Invariant NKT Cell Recognition of HIV-1–Infected Dendritic Cells Is an Early Detection Mechanism Targeted by Viral Immune Evasion

    PubMed Central

    Paquin-Proulx, Dominic; Gibbs, Anna; Bächle, Susanna M.; Checa, Antonio; Introini, Andrea; Leeansyah, Edwin; Wheelock, Craig E.; Nixon, Douglas F.; Broliden, Kristina; Tjernlund, Annelie; Moll, Markus

    2016-01-01

    Invariant NKT (iNKT) cells are innate-like T cells that respond rapidly with a broad range of effector functions upon recognition of glycolipid Ags presented by CD1d. HIV-1 carries Nef- and Vpu-dependent mechanisms to interfere with CD1d surface expression, indirectly suggesting a role for iNKT cells in control of HIV-1 infection. In this study, we investigated whether iNKT cells can participate in the innate cell–mediated immune response to HIV-1. Infection of dendritic cells (DCs) with Nef- and Vpu-deficient HIV-1 induced upregulation of CD1d in a TLR7-dependent manner. Infection of DCs caused modulation of enzymes in the sphingolipid pathway and enhanced expression of the endogenous glucosylceramide Ag. Importantly, iNKT cells responded specifically to rare DCs productively infected with Nef- and Vpu-defective HIV-1. Transmitted founder viral isolates differed in their CD1d downregulation capacity, suggesting that diverse strains may be differentially successful in inhibiting this pathway. Furthermore, both iNKT cells and DCs expressing CD1d and HIV receptors resided in the female genital mucosa, a site where HIV-1 transmission occurs. Taken together, these findings suggest that innate iNKT cell sensing of HIV-1 infection in DCs is an early immune detection mechanism, which is independent of priming and adaptive recognition of viral Ag, and is actively targeted by Nef- and Vpu-dependent viral immune evasion mechanisms. PMID:27481843

  4. Innate Invariant NKT Cell Recognition of HIV-1-Infected Dendritic Cells Is an Early Detection Mechanism Targeted by Viral Immune Evasion.

    PubMed

    Paquin-Proulx, Dominic; Gibbs, Anna; Bächle, Susanna M; Checa, Antonio; Introini, Andrea; Leeansyah, Edwin; Wheelock, Craig E; Nixon, Douglas F; Broliden, Kristina; Tjernlund, Annelie; Moll, Markus; Sandberg, Johan K

    2016-09-01

    Invariant NKT (iNKT) cells are innate-like T cells that respond rapidly with a broad range of effector functions upon recognition of glycolipid Ags presented by CD1d. HIV-1 carries Nef- and Vpu-dependent mechanisms to interfere with CD1d surface expression, indirectly suggesting a role for iNKT cells in control of HIV-1 infection. In this study, we investigated whether iNKT cells can participate in the innate cell-mediated immune response to HIV-1. Infection of dendritic cells (DCs) with Nef- and Vpu-deficient HIV-1 induced upregulation of CD1d in a TLR7-dependent manner. Infection of DCs caused modulation of enzymes in the sphingolipid pathway and enhanced expression of the endogenous glucosylceramide Ag. Importantly, iNKT cells responded specifically to rare DCs productively infected with Nef- and Vpu-defective HIV-1. Transmitted founder viral isolates differed in their CD1d downregulation capacity, suggesting that diverse strains may be differentially successful in inhibiting this pathway. Furthermore, both iNKT cells and DCs expressing CD1d and HIV receptors resided in the female genital mucosa, a site where HIV-1 transmission occurs. Taken together, these findings suggest that innate iNKT cell sensing of HIV-1 infection in DCs is an early immune detection mechanism, which is independent of priming and adaptive recognition of viral Ag, and is actively targeted by Nef- and Vpu-dependent viral immune evasion mechanisms.

  5. Spatiotemporal Control of Type III-A CRISPR-Cas Immunity: Coupling DNA Degradation with the Target RNA Recognition.

    PubMed

    Kazlauskiene, Migle; Tamulaitis, Gintautas; Kostiuk, Georgij; Venclovas, Česlovas; Siksnys, Virginijus

    2016-04-21

    Streptococcus thermophilus (St) type III-A CRISPR-Cas system restricts MS2 RNA phage and cuts RNA in vitro. However, the CRISPR array spacers match DNA phages, raising the question: does the St CRISPR-Cas system provide immunity by erasing phage mRNA or/and by eliminating invading DNA? We show that it does both. We find that (1) base-pairing between crRNA and target RNA activates single-stranded DNA (ssDNA) degradation by StCsm; (2) ssDNase activity is confined to the HD-domain of Cas10; (3) target RNA cleavage by the Csm3 RNase suppresses Cas10 DNase activity, ensuring temporal control of DNA degradation; and (4) base-pairing between crRNA 5'-handle and target RNA 3'-flanking sequence inhibits Cas10 ssDNase to prevent self-targeting. We propose that upon phage infection, crRNA-guided StCsm binding to the emerging transcript recruits Cas10 DNase to the actively transcribed phage DNA, resulting in degradation of both the transcript and phage DNA, but not the host DNA. PMID:27105119

  6. Spatiotemporal Control of Type III-A CRISPR-Cas Immunity: Coupling DNA Degradation with the Target RNA Recognition.

    PubMed

    Kazlauskiene, Migle; Tamulaitis, Gintautas; Kostiuk, Georgij; Venclovas, Česlovas; Siksnys, Virginijus

    2016-04-21

    Streptococcus thermophilus (St) type III-A CRISPR-Cas system restricts MS2 RNA phage and cuts RNA in vitro. However, the CRISPR array spacers match DNA phages, raising the question: does the St CRISPR-Cas system provide immunity by erasing phage mRNA or/and by eliminating invading DNA? We show that it does both. We find that (1) base-pairing between crRNA and target RNA activates single-stranded DNA (ssDNA) degradation by StCsm; (2) ssDNase activity is confined to the HD-domain of Cas10; (3) target RNA cleavage by the Csm3 RNase suppresses Cas10 DNase activity, ensuring temporal control of DNA degradation; and (4) base-pairing between crRNA 5'-handle and target RNA 3'-flanking sequence inhibits Cas10 ssDNase to prevent self-targeting. We propose that upon phage infection, crRNA-guided StCsm binding to the emerging transcript recruits Cas10 DNase to the actively transcribed phage DNA, resulting in degradation of both the transcript and phage DNA, but not the host DNA.

  7. Tailored sensitivity reduction improves pattern recognition and information recovery with a higher tolerance to varied sample concentration for targeted urinary metabolomics.

    PubMed

    Yan, Zhixiang; Yan, Ru

    2016-04-22

    Variation in total metabolite concentration among different samples has been a major challenge for urinary metabolomics. Here we investigated the potential of tailored sensitivity reduction of high abundance metabolites for improved targeted urinary metabolomics. Two levels of sensitivity reduction of the 21 predominant urinary metabolites were assessed by employing less sensitive transition or collision energy with level 1 (reduced 1) and 2 (reduced 2) exhibiting 30-90% and 2-20% of the optimal sensitivity, respectively. Five postacquisition normalization methods were compared including no normalization, probabilistic quotient normalization, and normalization to sample median, creatinine intensity, and total intensity. Normalization to total intensity with reduced 2 gave the best pattern recognition and information recovery with a higher tolerance to varied sample concentration. Pareto scaling could improve the performance of tailored sensitivity reduction (reduced 2) for targeted urinary metabolomics while data transformation and autoscaling were susceptible to varied sample concentration. Using controlled spike-in experiments, we demonstrated that tailored sensitivity reduction revealed more differentially expressed markers with higher accuracy than did the conventional optimal sensitivity. This was particularly true when the differences between the sample groups are small. This work also served as an introductory guideline for handling targeted metabolomics data using the open-source software MetaboAnalyst.

  8. Stochastic and reversible assembly of a multiprotein DNA repair complex ensures accurate target site recognition and efficient repair

    PubMed Central

    Luijsterburg, Martijn S.; von Bornstaedt, Gesa; Gourdin, Audrey M.; Politi, Antonio Z.; Moné, Martijn J.; Warmerdam, Daniël O.; Goedhart, Joachim; Vermeulen, Wim

    2010-01-01

    To understand how multiprotein complexes assemble and function on chromatin, we combined quantitative analysis of the mammalian nucleotide excision DNA repair (NER) machinery in living cells with computational modeling. We found that individual NER components exchange within tens of seconds between the bound state in repair complexes and the diffusive state in the nucleoplasm, whereas their net accumulation at repair sites evolves over several hours. Based on these in vivo data, we developed a predictive kinetic model for the assembly and function of repair complexes. DNA repair is orchestrated by the interplay of reversible protein-binding events and progressive enzymatic modifications of the chromatin substrate. We demonstrate that faithful recognition of DNA lesions is time consuming, whereas subsequently, repair complexes form rapidly through random and reversible assembly of NER proteins. Our kinetic analysis of the NER system reveals a fundamental conflict between specificity and efficiency of chromatin-associated protein machineries and shows how a trade off is negotiated through reversibility of protein binding. PMID:20439997

  9. Stochastic and reversible assembly of a multiprotein DNA repair complex ensures accurate target site recognition and efficient repair.

    PubMed

    Luijsterburg, Martijn S; von Bornstaedt, Gesa; Gourdin, Audrey M; Politi, Antonio Z; Moné, Martijn J; Warmerdam, Daniël O; Goedhart, Joachim; Vermeulen, Wim; van Driel, Roel; Höfer, Thomas

    2010-05-01

    To understand how multiprotein complexes assemble and function on chromatin, we combined quantitative analysis of the mammalian nucleotide excision DNA repair (NER) machinery in living cells with computational modeling. We found that individual NER components exchange within tens of seconds between the bound state in repair complexes and the diffusive state in the nucleoplasm, whereas their net accumulation at repair sites evolves over several hours. Based on these in vivo data, we developed a predictive kinetic model for the assembly and function of repair complexes. DNA repair is orchestrated by the interplay of reversible protein-binding events and progressive enzymatic modifications of the chromatin substrate. We demonstrate that faithful recognition of DNA lesions is time consuming, whereas subsequently, repair complexes form rapidly through random and reversible assembly of NER proteins. Our kinetic analysis of the NER system reveals a fundamental conflict between specificity and efficiency of chromatin-associated protein machineries and shows how a trade off is negotiated through reversibility of protein binding. PMID:20439997

  10. Identification of putative drug targets in Vancomycin-resistant Staphylococcus aureus (VRSA) using computer aided protein data analysis.

    PubMed

    Hasan, Md Anayet; Khan, Md Arif; Sharmin, Tahmina; Hasan Mazumder, Md Habibul; Chowdhury, Afrin Sultana

    2016-01-01

    Vancomycin-resistant Staphylococcus aureus (VRSA) is a Gram-positive, facultative aerobic bacterium which is evolved from the extensive exposure of Vancomycin to Methicillin resistant S. aureus (MRSA) that had become the most common cause of hospital and community-acquired infections. Due to the emergence of different antibiotic resistance strains, there is an exigency to develop novel drug targets to address the provocation of multidrug-resistant bacteria. In this study, in-silico genome subtraction methodology was used to design potential and pathogen specific drug targets against VRSA. Our study divulged 1987 proteins from the proteome of 34,549 proteins, which have no homologues in human genome after sequential analysis through CD-HIT and BLASTp. The high stringency analysis of the remaining proteins against database of essential genes (DEG) resulted in 169 proteins which are essential for S. aureus. Metabolic pathway analysis of human host and pathogen by KAAS at the KEGG server sorted out 19 proteins involved in unique metabolic pathways. 26 human non-homologous membrane-bound essential proteins including 4 which were also involved in unique metabolic pathway were deduced through PSORTb, CELLO v.2.5, ngLOC. Functional classification of uncharacterized proteins through SVMprot derived 7 human non-homologous membrane-bound hypothetical essential proteins. Study of potential drug target against Drug Bank revealed pbpA-penicillin-binding protein 1 and hypothetical protein MQW_01796 as the best drug target candidate. 2D structure was predicted by PRED-TMBB, 3D structure and functional analysis was also performed. Protein-protein interaction network of potential drug target proteins was analyzed by using STRING. The identified drug targets are expected to have great potential for designing novel drugs against VRSA infections and further screening of the compounds against these new targets may result in the discovery of novel therapeutic compounds that can be

  11. Genome-Wide Targets Regulated by the OsMADS1 Transcription Factor Reveals Its DNA Recognition Properties1[OPEN

    PubMed Central

    Khanday, Imtiyaz; Das, Sanjukta; Chongloi, Grace L; Vijayraghavan, Usha

    2016-01-01

    OsMADS1 controls rice (Oryza sativa) floral fate and organ development. Yet, its genome-wide targets and the mechanisms underlying its role as a transcription regulator controlling developmental gene expression are unknown. We identify 3112 gene-associated OsMADS1-bound sites in the floret genome. These occur in the vicinity of transcription start sites, within gene bodies, and in intergenic regions. Majority of the bound DNA contained CArG motif variants or, in several cases, only A-tracts. Sequences flanking the binding peak had a higher AT nucleotide content, implying that broader DNA structural features may define in planta binding. Sequences for binding by other transcription factor families like MYC, AP2/ERF, bZIP, etc. are enriched in OsMADS1-bound DNAs. Target genes implicated in transcription, chromatin remodeling, cellular processes, and hormone metabolism were enriched. Combining expression data from OsMADS1 knockdown florets with these DNA binding data, a snapshot of a gene regulatory network was deduced where targets, such as AP2/ERF and bHLH transcription factors and chromatin remodelers form nodes. We show that the expression status of these nodal factors can be altered by inducing the OsMADS1-GR fusion protein and present a model for a regulatory cascade where the direct targets of OsMADS1, OsbHLH108/SPT, OsERF034, and OsHSF24, in turn control genes such as OsMADS32 and OsYABBY5. This cascade, with other similar relationships, cumulatively contributes to floral organ development. Overall, OsMADS1 binds to several regulatory genes and, probably in combination with other factors, controls a gene regulatory network that ensures rice floret development. PMID:27457124

  12. Genome-Wide Targets Regulated by the OsMADS1 Transcription Factor Reveals Its DNA Recognition Properties.

    PubMed

    Khanday, Imtiyaz; Das, Sanjukta; Chongloi, Grace L; Bansal, Manju; Grossniklaus, Ueli; Vijayraghavan, Usha

    2016-09-01

    OsMADS1 controls rice (Oryza sativa) floral fate and organ development. Yet, its genome-wide targets and the mechanisms underlying its role as a transcription regulator controlling developmental gene expression are unknown. We identify 3112 gene-associated OsMADS1-bound sites in the floret genome. These occur in the vicinity of transcription start sites, within gene bodies, and in intergenic regions. Majority of the bound DNA contained CArG motif variants or, in several cases, only A-tracts. Sequences flanking the binding peak had a higher AT nucleotide content, implying that broader DNA structural features may define in planta binding. Sequences for binding by other transcription factor families like MYC, AP2/ERF, bZIP, etc. are enriched in OsMADS1-bound DNAs. Target genes implicated in transcription, chromatin remodeling, cellular processes, and hormone metabolism were enriched. Combining expression data from OsMADS1 knockdown florets with these DNA binding data, a snapshot of a gene regulatory network was deduced where targets, such as AP2/ERF and bHLH transcription factors and chromatin remodelers form nodes. We show that the expression status of these nodal factors can be altered by inducing the OsMADS1-GR fusion protein and present a model for a regulatory cascade where the direct targets of OsMADS1, OsbHLH108/SPT, OsERF034, and OsHSF24, in turn control genes such as OsMADS32 and OsYABBY5 This cascade, with other similar relationships, cumulatively contributes to floral organ development. Overall, OsMADS1 binds to several regulatory genes and, probably in combination with other factors, controls a gene regulatory network that ensures rice floret development. PMID:27457124

  13. Targeted complement inhibition by C3d recognition ameliorates tissue injury without apparent increase in susceptibility to infection.

    PubMed

    Atkinson, Carl; Song, Hongbin; Lu, Bo; Qiao, Fei; Burns, Tara A; Holers, V Michael; Tsokos, George C; Tomlinson, Stephen

    2005-09-01

    Previous studies indicate a pivotal role for complement in mediating both local and remote injury following ischemia and reperfusion of the intestine. Here, we report on the use of a mouse model of intestinal ischemia/reperfusion injury to investigate the strategy of targeting complement inhibition to sites of complement activation by linking an iC3b/C3dg-binding fragment of mouse complement receptor 2 (CR2) to a mouse complement-inhibitory protein, Crry. We show that the novel CR2-Crry fusion protein targets sites of local and remote (lung) complement activation following intestinal ischemia and reperfusion injury and that CR2-Crry requires a 10-fold lower dose than its systemic counterpart, Crry-Ig, to provide equivalent protection from both local and remote injury. CR2-Crry has a significantly shorter serum half-life than Crry-Ig and, unlike Crry-Ig, had no significant effect on serum complement activity at minimum effective therapeutic doses. Furthermore, the minimum effective dose of Crry-Ig significantly enhanced susceptibility to infection in a mouse model of acute septic peritonitis, whereas the effect of CR2-Crry on susceptibility to infection was indistinguishable from that of PBS control. Thus, compared with systemic inhibition, CR2-mediated targeting of a complement inhibitor of activation improved bioavailability, significantly enhanced efficacy, and maintained host resistance to infection.

  14. RNA editing of microRNA prevents RNA-induced silencing complex recognition of target mRNA

    PubMed Central

    Cui, Yalei; Huang, Tianzhi; Zhang, Xiaobo

    2015-01-01

    MicroRNAs (miRNAs) integrate with Argonaut (Ago) to create the RNA-induced silencing complex, and regulate gene expression by silencing target mRNAs. RNA editing of miRNA may affect miRNA processing, assembly of the Ago complex and target mRNA binding. However, the function of edited miRNA, assembled within the Ago complex, has not been extensively investigated. In this study, sequence analysis of the Ago complex of Marsupenaeus japonicus shrimp infected with white spot syndrome virus (WSSV) revealed that host ADAR (adenosine deaminase acting on RNA) catalysed A-to-I RNA editing of a viral miRNA (WSSV-miR-N12) at the +16 site. This editing of the non-seed sequence did not affect association of the edited miRNA with the Ago protein, but inhibited interaction between the miRNA and its target gene (wsv399). The WSSV early gene wsv399 inhibited WSSV infection. As a result, the RNA editing of miRNA caused virus latency. Our results highlight a novel example of miRNA editing in the miRNA-induced silencing complex. PMID:26674414

  15. Targeted complement inhibition by C3d recognition ameliorates tissue injury without apparent increase in susceptibility to infection.

    PubMed

    Atkinson, Carl; Song, Hongbin; Lu, Bo; Qiao, Fei; Burns, Tara A; Holers, V Michael; Tsokos, George C; Tomlinson, Stephen

    2005-09-01

    Previous studies indicate a pivotal role for complement in mediating both local and remote injury following ischemia and reperfusion of the intestine. Here, we report on the use of a mouse model of intestinal ischemia/reperfusion injury to investigate the strategy of targeting complement inhibition to sites of complement activation by linking an iC3b/C3dg-binding fragment of mouse complement receptor 2 (CR2) to a mouse complement-inhibitory protein, Crry. We show that the novel CR2-Crry fusion protein targets sites of local and remote (lung) complement activation following intestinal ischemia and reperfusion injury and that CR2-Crry requires a 10-fold lower dose than its systemic counterpart, Crry-Ig, to provide equivalent protection from both local and remote injury. CR2-Crry has a significantly shorter serum half-life than Crry-Ig and, unlike Crry-Ig, had no significant effect on serum complement activity at minimum effective therapeutic doses. Furthermore, the minimum effective dose of Crry-Ig significantly enhanced susceptibility to infection in a mouse model of acute septic peritonitis, whereas the effect of CR2-Crry on susceptibility to infection was indistinguishable from that of PBS control. Thus, compared with systemic inhibition, CR2-mediated targeting of a complement inhibitor of activation improved bioavailability, significantly enhanced efficacy, and maintained host resistance to infection. PMID:16127466

  16. RNA editing of microRNA prevents RNA-induced silencing complex recognition of target mRNA.

    PubMed

    Cui, Yalei; Huang, Tianzhi; Zhang, Xiaobo

    2015-12-01

    MicroRNAs (miRNAs) integrate with Argonaut (Ago) to create the RNA-induced silencing complex, and regulate gene expression by silencing target mRNAs. RNA editing of miRNA may affect miRNA processing, assembly of the Ago complex and target mRNA binding. However, the function of edited miRNA, assembled within the Ago complex, has not been extensively investigated. In this study, sequence analysis of the Ago complex of Marsupenaeus japonicus shrimp infected with white spot syndrome virus (WSSV) revealed that host ADAR (adenosine deaminase acting on RNA) catalysed A-to-I RNA editing of a viral miRNA (WSSV-miR-N12) at the +16 site. This editing of the non-seed sequence did not affect association of the edited miRNA with the Ago protein, but inhibited interaction between the miRNA and its target gene (wsv399). The WSSV early gene wsv399 inhibited WSSV infection. As a result, the RNA editing of miRNA caused virus latency. Our results highlight a novel example of miRNA editing in the miRNA-induced silencing complex.

  17. Digital fast pattern recognizer for autonomous target recognition and tracking for advanced missile guidance and UAV reconnaissance

    NASA Astrophysics Data System (ADS)

    Hastbacka, Albin A.

    2003-08-01

    A digital Fast Pattern Processor (DFPP) system under development for the Naval Air Warfare Center, is funded under a SBIR, Phase III contract. It is an automatic target recognizer and tracker candidate for supersonic missile guidance and unmanned air vehicle (UAV) reconnaissance to meet the U.S. navy's time-critical strike objectives. The former application requires rapid processing of moderate size, real time image arrays, versus large real time image arrays for the latter case. The DFPP correlates operator selected target filters against observed imagery at 1500 correlations per second as currently implemented with programmable logic devices (PLD's) - equivalent to thirty Pentium III (1 GHz) PC's. High performance and low weight, power, size, cost of the current version make it ideal for on-board image data processing in UAV's and cruise missiles or for ground station processing. Conversion to application specific integrated circuit (ASIC) technology provides scalable performance to meet future ATR/ATT needs. The Sanders proprietary DFPP technology embodies a Power-FFT, which is the fastest digital fast Fourier transform (DFTT) in the world with performance exceeding supercomputers, at a small fraction of the cost, size, weight, and power. The DFPP operates under control of Sanders Correlation Image Processor (SCIP) program and enables correlation against a plethora of stored target filters (templates).

  18. Quantification of susceptibility change at high-concentrated SPIO-labeled target by characteristic phase gradient recognition.

    PubMed

    Zhu, Haitao; Nie, Binbin; Liu, Hua; Guo, Hua; Demachi, Kazuyuki; Sekino, Masaki; Shan, Baoci

    2016-05-01

    Phase map cross-correlation detection and quantification may produce highlighted signal at superparamagnetic iron oxide nanoparticles, and distinguish them from other hypointensities. The method may quantify susceptibility change by performing least squares analysis between a theoretically generated magnetic field template and an experimentally scanned phase image. Because characteristic phase recognition requires the removal of phase wrap and phase background, additional steps of phase unwrapping and filtering may increase the chance of computing error and enlarge the inconsistence among algorithms. To solve problem, phase gradient cross-correlation and quantification method is developed by recognizing characteristic phase gradient pattern instead of phase image because phase gradient operation inherently includes unwrapping and filtering functions. However, few studies have mentioned the detectable limit of currently used phase gradient calculation algorithms. The limit may lead to an underestimation of large magnetic susceptibility change caused by high-concentrated iron accumulation. In this study, mathematical derivation points out the value of maximum detectable phase gradient calculated by differential chain algorithm in both spatial and Fourier domain. To break through the limit, a modified quantification method is proposed by using unwrapped forward differentiation for phase gradient generation. The method enlarges the detectable range of phase gradient measurement and avoids the underestimation of magnetic susceptibility. Simulation and phantom experiments were used to quantitatively compare different methods. In vivo application performs MRI scanning on nude mice implanted by iron-labeled human cancer cells. Results validate the limit of detectable phase gradient and the consequent susceptibility underestimation. Results also demonstrate the advantage of unwrapped forward differentiation compared with differential chain algorithms for susceptibility

  19. Early T Cell Recognition of B Cells following Epstein-Barr Virus Infection: Identifying Potential Targets for Prophylactic Vaccination

    PubMed Central

    Brooks, Jill M.; Long, Heather M.; Tierney, Rose J.; Shannon-Lowe, Claire; Leese, Alison M.; Fitzpatrick, Martin; Taylor, Graham S.; Rickinson, Alan B.

    2016-01-01

    Epstein-Barr virus, a B-lymphotropic herpesvirus, is the cause of infectious mononucleosis, has strong aetiologic links with several malignancies and has been implicated in certain autoimmune diseases. Efforts to develop a prophylactic vaccine to prevent or reduce EBV-associated disease have, to date, focused on the induction of neutralising antibody responses. However, such vaccines might be further improved by inducing T cell responses capable of recognising and killing recently-infected B cells. In that context, EBNA2, EBNA-LP and BHRF1 are the first viral antigens expressed during the initial stage of B cell growth transformation, yet have been poorly characterised as CD8+ T cell targets. Here we describe CD8+ T cell responses against each of these three “first wave” proteins, identifying target epitopes and HLA restricting alleles. While EBNA-LP and BHRF1 each contained one strong CD8 epitope, epitopes within EBNA2 induced immunodominant responses through several less common HLA class I alleles (e.g. B*3801 and B*5501), as well as subdominant responses through common class I alleles (e.g. B7 and C*0304). Importantly, such EBNA2-specific CD8+ T cells recognised B cells within the first day post-infection, prior to CD8+ T cells against well-characterised latent target antigens such as EBNA3B or LMP2, and effectively inhibited outgrowth of EBV-transformed B cell lines. We infer that “first wave” antigens of the growth-transforming infection, especially EBNA2, constitute potential CD8+ T cell immunogens for inclusion in prophylactic EBV vaccine design. PMID:27096949

  20. EBV latent membrane proteins (LMPs) 1 and 2 as immunotherapeutic targets: LMP-specific CD4+ cytotoxic T cell recognition of EBV-transformed B cell lines.

    PubMed

    Haigh, Tracey A; Lin, Xiaorong; Jia, Hui; Hui, Edwin P; Chan, Anthony T C; Rickinson, Alan B; Taylor, Graham S

    2008-02-01

    The EBV-latent membrane proteins (LMPs) 1 and 2 are among only three viral proteins expressed in EBV-associated Hodgkin's lymphoma and nasopharyngeal carcinoma. Since these tumors are HLA class I and class II-positive, the LMPs could serve as both CD8+ and CD4+ T cell targets. In contrast to CD8 responses, very little is known about CD4 responses to LMPs. In this study, we describe CD4+ T cell clones defining four LMP1- and three LMP2-derived peptide epitopes and their restricting alleles. All clones produced Th1-like cytokines in response to peptide and most killed peptide-loaded target cells by perforin-mediated lysis. Although clones to different epitopes showed different functional avidities in peptide titration assays, avidity per se was a poor predictor of the ability to recognize naturally infected B lymphoblastoid cell lines (LCLs) expressing LMPs at physiologic levels. Some epitopes, particularly within LMP1, consistently mediated strong LCL recognition detectable in cytokine release, cytotoxicity, and outgrowth inhibition assays. Using cyclosporin A to selectively block cytokine release, we found that CD4+ T cell cytotoxicity is the key effector of LCL outgrowth control. We therefore infer that cytotoxic CD4+ T cells to a subset of LMP epitopes could have therapeutic potential against LMP-expressing tumors.

  1. CTLs are targeted to kill β cells in patients with type 1 diabetes through recognition of a glucose-regulated preproinsulin epitope

    PubMed Central

    Skowera, Ania; Ellis, Richard J.; Varela-Calviño, Ruben; Arif, Sefina; Huang, Guo Cai; Van-Krinks, Cassie; Zaremba, Anna; Rackham, Chloe; Allen, Jennifer S.; Tree, Timothy I.M.; Zhao, Min; Dayan, Colin M.; Sewell, Andrew K.; Unger, Wendy; Drijfhout, Jan W.; Ossendorp, Ferry; Roep, Bart O.; Peakman, Mark

    2008-01-01

    The final pathway of β cell destruction leading to insulin deficiency, hyperglycemia, and clinical type 1 diabetes is unknown. Here we show that circulating CTLs can kill β cells via recognition of a glucose-regulated epitope. First, we identified 2 naturally processed epitopes from the human preproinsulin signal peptide by elution from HLA-A2 (specifically, the protein encoded by the A*0201 allele) molecules. Processing of these was unconventional, requiring neither the proteasome nor transporter associated with processing (TAP). However, both epitopes were major targets for circulating effector CD8+ T cells from HLA-A2+ patients with type 1 diabetes. Moreover, cloned preproinsulin signal peptide–specific CD8+ T cells killed human β cells in vitro. Critically, at high glucose concentration, β cell presentation of preproinsulin signal epitope increased, as did CTL killing. This study provides direct evidence that autoreactive CTLs are present in the circulation of patients with type 1 diabetes and that they can kill human β cells. These results also identify a mechanism of self-antigen presentation that is under pathophysiological regulation and could expose insulin-producing β cells to increasing cytotoxicity at the later stages of the development of clinical diabetes. Our findings suggest that autoreactive CTLs are important targets for immune-based interventions in type 1 diabetes and argue for early, aggressive insulin therapy to preserve remaining β cells. PMID:18802479

  2. CTLs are targeted to kill beta cells in patients with type 1 diabetes through recognition of a glucose-regulated preproinsulin epitope.

    PubMed

    Skowera, Ania; Ellis, Richard J; Varela-Calviño, Ruben; Arif, Sefina; Huang, Guo Cai; Van-Krinks, Cassie; Zaremba, Anna; Rackham, Chloe; Allen, Jennifer S; Tree, Timothy I M; Zhao, Min; Dayan, Colin M; Sewell, Andrew K; Unger, Wendy W; Unger, Wendy; Drijfhout, Jan W; Ossendorp, Ferry; Roep, Bart O; Peakman, Mark

    2008-10-01

    The final pathway of beta cell destruction leading to insulin deficiency, hyperglycemia, and clinical type 1 diabetes is unknown. Here we show that circulating CTLs can kill beta cells via recognition of a glucose-regulated epitope. First, we identified 2 naturally processed epitopes from the human preproinsulin signal peptide by elution from HLA-A2 (specifically, the protein encoded by the A*0201 allele) molecules. Processing of these was unconventional, requiring neither the proteasome nor transporter associated with processing (TAP). However, both epitopes were major targets for circulating effector CD8+ T cells from HLA-A2+ patients with type 1 diabetes. Moreover, cloned preproinsulin signal peptide-specific CD8+ T cells killed human beta cells in vitro. Critically, at high glucose concentration, beta cell presentation of preproinsulin signal epitope increased, as did CTL killing. This study provides direct evidence that autoreactive CTLs are present in the circulation of patients with type 1 diabetes and that they can kill human beta cells. These results also identify a mechanism of self-antigen presentation that is under pathophysiological regulation and could expose insulin-producing beta cells to increasing cytotoxicity at the later stages of the development of clinical diabetes. Our findings suggest that autoreactive CTLs are important targets for immune-based interventions in type 1 diabetes and argue for early, aggressive insulin therapy to preserve remaining beta cells.

  3. Project Roadmap: Reeducating Older Adults in Maintaining AIDS Prevention--A Secondary Intervention for Older HIV-Positive Adults

    ERIC Educational Resources Information Center

    Illa, Lourdes; Echenique, Marisa; Saint Jean, Gilbert; Bustamante-Avellaneda, Victoria; Metsch, Lisa; Mendez-Mulet, Luis; Eisdorfer, Carl; Sanchez-Martinez, Mario

    2010-01-01

    The number of older adults living with HIV/AIDS is larger than ever. Little is known about their sexual behaviors, although contrary to stereotypes, older adults desire and engage in sexual activity. Despite increased recognition of the need for prevention interventions targeting HIV-positive individuals, no secondary HIV prevention interventions…

  4. Testing of Haar-Like Feature in Region of Interest Detection for Automated Target Recognition (ATR) System

    NASA Technical Reports Server (NTRS)

    Zhang, Yuhan; Lu, Dr. Thomas

    2010-01-01

    The objectives of this project were to develop a ROI (Region of Interest) detector using Haar-like feature similar to the face detection in Intel's OpenCV library, implement it in Matlab code, and test the performance of the new ROI detector against the existing ROI detector that uses Optimal Trade-off Maximum Average Correlation Height filter (OTMACH). The ROI detector included 3 parts: 1, Automated Haar-like feature selection in finding a small set of the most relevant Haar-like features for detecting ROIs that contained a target. 2, Having the small set of Haar-like features from the last step, a neural network needed to be trained to recognize ROIs with targets by taking the Haar-like features as inputs. 3, using the trained neural network from the last step, a filtering method needed to be developed to process the neural network responses into a small set of regions of interests. This needed to be coded in Matlab. All the 3 parts needed to be coded in Matlab. The parameters in the detector needed to be trained by machine learning and tested with specific datasets. Since OpenCV library and Haar-like feature were not available in Matlab, the Haar-like feature calculation needed to be implemented in Matlab. The codes for Adaptive Boosting and max/min filters in Matlab could to be found from the Internet but needed to be integrated to serve the purpose of this project. The performance of the new detector was tested by comparing the accuracy and the speed of the new detector against the existing OTMACH detector. The speed was referred as the average speed to find the regions of interests in an image. The accuracy was measured by the number of false positives (false alarms) at the same detection rate between the two detectors.

  5. A prostate cancer computer-aided diagnosis system using multimodal magnetic resonance imaging and targeted biopsy labels

    NASA Astrophysics Data System (ADS)

    Liu, Peter; Wang, Shijun; Turkbey, Baris; Grant, Kinzya; Pinto, Peter; Choyke, Peter; Wood, Bradford J.; Summers, Ronald M.

    2013-02-01

    We propose a new method for prostate cancer classification based on supervised statistical learning methods by integrating T2-weighted, diffusion-weighted, and dynamic contrast-enhanced MRI images with targeted prostate biopsy results. In the first step of the method, all three imaging modalities are registered based on the image coordinates encoded in the DICOM images. In the second step, local statistical features are extracted in each imaging modality to capture intensity, shape, and texture information at every biopsy target. Finally, using support vector machines, supervised learning is conducted with the biopsy results to train a classification system that predicts the pathology of suspicious cancer lesions. The algorithm was tested with a dataset of 54 patients that underwent 164 targeted biopsies (58 positive, 106 negative). The proposed tri-modal MRI algorithm shows significant improvement over a similar approach that utilizes only T2-weighted MRI images (p= 0.048). The areas under the ROC curve for these methods were 0.82 (95% CI: [0.71, 0.93]) and 0.73 (95% CI: [0.55, 0.84]), respectively.

  6. Monoclonal antibodies toward different Tn-amino acid backbones display distinct recognition patterns on human cancer cells. Implications for effective immuno-targeting of cancer.

    PubMed

    Mazal, Daniel; Lo-Man, Richard; Bay, Sylvie; Pritsch, Otto; Dériaud, Edith; Ganneau, Christelle; Medeiros, Andrea; Ubillos, Luis; Obal, Gonzalo; Berois, Nora; Bollati-Fogolin, Mariela; Leclerc, Claude; Osinaga, Eduardo

    2013-06-01

    The Tn antigen (GalNAcα-O-Ser/Thr) is a well-established tumor-associated marker which represents a good target for the design of anti-tumor vaccines. Several studies have established that the binding of some anti-Tn antibodies could be affected by the density of Tn determinant or/and by the amino acid residues neighboring O-glycosylation sites. In the present study, using synthetic Tn-based vaccines, we have generated a panel of anti-Tn monoclonal antibodies. Analysis of their binding to various synthetic glycopeptides, modifying the amino acid carrier of the GalNAc(*) (Ser* vs Thr*), showed subtle differences in their fine specificities. We found that the recognition of these glycopeptides by some of these MAbs was strongly affected by the Tn backbone, such as a S*S*S* specific MAb (15G9) which failed to recognize a S*T*T* or a T*T*T* structure. Different binding patterns of these antibodies were also observed in FACS and Western blot analysis using three human cancer cell lines (MCF-7, LS174T and Jurkat). Importantly, an immunohistochemical analysis of human tumors (72 breast cancer and 44 colon cancer) showed the existence of different recognition profiles among the five antibodies evaluated, demonstrating that the aglyconic part of the Tn structure (Ser vs Thr) plays a key role in the anti-Tn specificity for breast and colon cancer detection. This new structural feature of the Tn antigen could be of important clinical value, notably due to the increasing interest of this antigen in anticancer vaccine design as well as for the development of anti-Tn antibodies for in vivo diagnostic and therapeutic strategies.

  7. Cerebrovascular Dilation via Selective Targeting of the Cholane Steroid-Recognition Site in the BK Channel β1-Subunit by a Novel Nonsteroidal Agent

    PubMed Central

    Bukiya, Anna N.; McMillan, Jacob E.; Fedinec, Alexander L.; Patil, Shivaputra A.; Miller, Duane D.; Leffler, Charles W.; Parrill, Abby L.

    2013-01-01

    The Ca2+/voltage-gated K+ large conductance (BK) channel β1 subunit is particularly abundant in vascular smooth muscle. By determining their phenotype, BK β1 allows the BK channels to reduce myogenic tone, facilitating vasodilation. The endogenous steroid lithocholic acid (LCA) dilates cerebral arteries via BK channel activation, which requires recognition by a BK β1 site that includes Thr169. Whether exogenous nonsteroidal agents can access this site to selectively activate β1-containing BK channels and evoke vasodilation remain unknown. We performed a chemical structure database similarity search using LCA as a template, along with a two-step reaction to generate sodium 3-hydroxyolean-12-en-30-oate (HENA). HENA activated the BK (cbv1 + β1) channels cloned from rat cerebral artery myocytes with a potency (EC50 = 53 μM) similar to and an efficacy (×2.5 potentiation) significantly greater than that of LCA. This HENA action was replicated on native channels in rat cerebral artery myocytes. HENA failed to activate the channels made of cbv1 + β2, β3, β4, or β1T169A, indicating that this drug selectively targets β1-containing BK channels via the BK β1 steroid-sensing site. HENA (3–45 μM) dilated the rat and C57BL/6 mouse pressurized cerebral arteries. Consistent with the electrophysiologic results, this effect was larger than that of LCA. HENA failed to dilate the arteries from the KCNMB1 knockout mouse, underscoring BK β1’s role in HENA action. Finally, carotid artery-infusion of HENA (45 μM) dilated the pial cerebral arterioles via selective BK-channel targeting. In conclusion, we have identified for the first time a nonsteroidal agent that selectively activates β1-containing BK channels by targeting the steroid-sensing site in BK β1, rendering vasodilation. PMID:23455312

  8. A Targeted “Capture” and “Removal” Scavenger toward Multiple Pollutants for Water Remediation based on Molecular Recognition

    PubMed Central

    Wang, Jie; Shen, Haijing; Hu, Xiaoxia; Li, Yan; Li, Zhihao; Xu, Jinfan; Song, Xiufeng; Zeng, Haibo

    2015-01-01

    For the water remediation techniques based on adsorption, the long‐standing contradictories between selectivity and multiple adsorbability, as well as between affinity and recyclability, have put it on weak defense amid more and more severe environment crisis. Here, a pollutant‐targeting hydrogel scavenger is reported for water remediation with both high selectivity and multiple adsorbability for several pollutants, and with strong affinity and good recyclability through rationally integrating the advantages of multiple functional materials. In the scavenger, aptamers fold into binding pockets to accommodate the molecular structure of pollutants to afford perfect selectivity, and Janus nanoparticles with antibacterial function as well as anisotropic surfaces to immobilize multiple aptamers allow for simultaneously handling different kinds of pollutants. The scavenger exhibits high efficiencies in removing pollutants from water and it can be easily recycled for many times without significant loss of loading capacities. Moreover, the residual concentrations of each contaminant are well below the drinking water standards. Thermodynamic behavior of the adsorption process is investigated and the rate‐controlling process is determined. Furthermore, a point of use device is constructed and it displays high efficiency in removing pollutants from environmental water. The scavenger exhibits great promise to be applied in the next generation of water purification systems.

  9. Stepwise phosphorylation of p65 promotes NF-κB activation and NK cell responses during target cell recognition

    PubMed Central

    Kwon, Hyung-Joon; Choi, Go-Eun; Ryu, Sangryeol; Kwon, Soon Jae; Kim, Sun Chang; Booth, Claire; Nichols, Kim E.; Kim, Hun Sik

    2016-01-01

    NF-κB is a key transcription factor that dictates the outcome of diverse immune responses. How NF-κB is regulated by multiple activating receptors that are engaged during natural killer (NK)-target cell contact remains undefined. Here we show that sole engagement of NKG2D, 2B4 or DNAM-1 is insufficient for NF-κB activation. Rather, cooperation between these receptors is required at the level of Vav1 for synergistic NF-κB activation. Vav1-dependent synergistic signalling requires a separate PI3K-Akt signal, primarily mediated by NKG2D or DNAM-1, for optimal p65 phosphorylation and NF-κB activation. Vav1 controls downstream p65 phosphorylation and NF-κB activation. Synergistic signalling is defective in X-linked lymphoproliferative disease (XLP1) NK cells entailing 2B4 dysfunction and required for p65 phosphorylation by PI3K-Akt signal, suggesting stepwise signalling checkpoint for NF-κB activation. Thus, our study provides a framework explaining how signals from different activating receptors are coordinated to determine specificity and magnitude of NF-κB activation and NK cell responses. PMID:27221592

  10. Requirement of the FATC domain of protein kinase Tel1 for localization to DNA ends and target protein recognition.

    PubMed

    Ogi, Hiroo; Goto, Greicy H; Ghosh, Avik; Zencir, Sevil; Henry, Everett; Sugimoto, Katsunori

    2015-10-01

    Two large phosphatidylinositol 3-kinase-related protein kinases (PIKKs), ATM and ATR, play a central role in the DNA damage response pathway. PIKKs contain a highly conserved extreme C-terminus called the FRAP-ATM-TRRAP-C-terminal (FATC) domain. In budding yeast, ATM and ATR correspond to Tel1 and Mec1, respectively. In this study, we characterized functions of the FATC domain of Tel1 by introducing substitution or truncation mutations. One substitution mutation, termed tel1-21, and a truncation mutation, called tel1-ΔC, did not significantly affect the expression level. The tel1-21 mutation impaired the cellular response to DNA damage and conferred moderate telomere maintenance defect. In contrast, the tel1-ΔC mutation behaved like a null mutation, conferring defects in both DNA damage response and telomere maintenance. Tel1-21 protein localized to DNA ends as effectively as wild-type Tel1 protein, whereas Tel1-ΔC protein failed. Introduction of a hyperactive TEL1-hy mutation suppressed the tel1-21 mutation but not the tel1-ΔC mutation. In vitro analyses revealed that both Tel1-21 and Tel1-ΔC proteins undergo efficient autophosphorylation but exhibit decreased kinase activities toward the exogenous substrate protein, Rad53. Our results show that the FATC domain of Tel1 mediates localization to DNA ends and contributes to phosphorylation of target proteins.

  11. Recognition Tunneling

    PubMed Central

    Lindsay, Stuart; He, Jin; Sankey, Otto; Hapala, Prokop; Jelinek, Pavel; Zhang, Peiming; Chang, Shuai; Huang, Shuo

    2010-01-01

    Single molecules in a tunnel junction can now be interrogated reliably using chemically-functionalized electrodes. Monitoring stochastic bonding fluctuations between a ligand bound to one electrode and its target bound to a second electrode (“tethered molecule-pair” configuration) gives insight into the nature of the intermolecular bonding at a single molecule-pair level, and defines the requirements for reproducible tunneling data. Simulations show that there is an instability in the tunnel gap at large currents, and this results in a multiplicity of contacts with a corresponding spread in the measured currents. At small currents (i.e. large gaps) the gap is stable, and functionalizing a pair of electrodes with recognition reagents (the “free analyte” configuration) can generate a distinct tunneling signal when an analyte molecule is trapped in the gap. This opens up a new interface between chemistry and electronics with immediate implications for rapid sequencing of single DNA molecules. PMID:20522930

  12. Human sterol 14α-demethylase as a target for anticancer chemotherapy: towards structure-aided drug design.

    PubMed

    Hargrove, Tatiana Y; Friggeri, Laura; Wawrzak, Zdzislaw; Sivakumaran, Suneethi; Yazlovitskaya, Eugenia M; Hiebert, Scott W; Guengerich, F Peter; Waterman, Michael R; Lepesheva, Galina I

    2016-08-01

    Rapidly multiplying cancer cells synthesize greater amounts of cholesterol to build their membranes. Cholesterol-lowering drugs (statins) are currently in clinical trials for anticancer chemotherapy. However, given at higher doses, statins cause serious side effects by inhibiting the formation of other biologically important molecules derived from mevalonate. Sterol 14α-demethylase (CYP51), which acts 10 steps downstream, is potentially a more specific drug target because this portion of the pathway is fully committed to cholesterol production. However, screening a variety of commercial and experimental inhibitors of microbial CYP51 orthologs revealed that most of them (including all clinical antifungals) weakly inhibit human CYP51 activity, even if they display high apparent spectral binding affinity. Only one relatively potent compound, (R)-N-(1-(3,4'-difluorobiphenyl-4-yl)-2-(1H-imidazol-1-yl)ethyl)-4-(5-phenyl-1,3,4-oxadiazol-2-yl)benzamide (VFV), was identified. VFV has been further tested in cellular experiments and found to decrease proliferation of different cancer cell types. The crystal structures of human CYP51-VFV complexes (2.0 and 2.5 Å) both display a 2:1 inhibitor/enzyme stoichiometry, provide molecular insights regarding a broader substrate profile, faster catalysis, and weaker susceptibility of human CYP51 to inhibition, and outline directions for the development of more potent inhibitors.

  13. Lexical and context effects in children's audiovisual speech recognition

    NASA Astrophysics Data System (ADS)

    Holt, Rachael; Kirk, Karen; Pisoni, David; Burckhartzmeyer, Lisa; Lin, Anna

    2005-09-01

    The Audiovisual Lexical Neighborhood Sentence Test (AVLNST), a new, recorded speech recognition test for children with sensory aids, was administered in multiple presentation modalities to children with normal hearing and vision. Each sentence consists of three key words whose lexical difficulty is controlled according to the Neighborhood Activation Model (NAM) of spoken word recognition. According to NAM, the recognition of spoken words is influenced by two lexical factors: the frequency of occurrence of individual words in a language, and how phonemically similar the target word is to other words in the listeners lexicon. These predictions are based on auditory similarity only, and thus do not take into account how visual information can influence the perception of speech. Data from the AVLNST, together with those from recorded audiovisual versions of isolated word recognition measures, the Lexical Neighborhood, and the Multisyllabic Lexical Neighborhood Tests, were used to examine the influence of visual information on speech perception in children. Further, the influence of top-down processing on speech recognition was examined by evaluating performance on the recognition of words in isolation versus words in sentences. [Work supported by the American Speech-Language-Hearing Foundation, the American Hearing Research Foundation, and the NIDCD, T32 DC00012 to Indiana University.

  14. Targeting the SAVA (Substance Abuse, Violence and AIDS) Syndemic among Women and Girls: A Global Review of Epidemiology and Integrated Interventions

    PubMed Central

    Gilbert, Louisa; Raj, Anita; Hien, Denise; Stockman, Jamila; Terlikbayeva, Assel; Wyatt, Gail

    2016-01-01

    Objectives Multiple pathways link gender-based violence (GBV) to HIV and other sexually transmitted infections (STIs) among women and girls who use or inject drugs. The aim of this paper is to synthesize global literature that examines associations among the synergistic epidemics of substance abuse, violence and HIV/AIDS, known as the SAVA syndemic. It also aims to identify a continuum of multi-level integrated interventions that target key SAVA syndemic mechanisms. Methods We conducted a selective search strategy, prioritizing use of meta-analytic epidemiological and intervention studies that address different aspects of the SAVA syndemic among women and girls who use drugs worldwide from 2000–2015 using PubMed, MEDLINE, and Google Scholar. Results Robust evidence from different countries suggests that GBV significantly increases the risk of HIV and other STIs among women and girls who use drugs. Multiple structural, biological and behavioral mechanisms link GBV and HIV among women and girls. Emerging research has identified a continuum of brief and extended multi-level GBV prevention and treatment interventions that may be integrated into a continuum of HIV prevention, testing, and treatment interventions to target key SAVA syndemic mechanisms among women and girls who use drugs. Conclusion There remain significant methodological and geographical gaps in epidemiological and intervention research on the SAVA syndemic, particularly in low and middle-income countries. This global review underscores the need to advance a continuum of multi-level integrated interventions that target salient mechanisms of the SAVA syndemic, especially for adolescent girls, young women and transgender women who use drugs. PMID:25978478

  15. Progress in fold recognition.

    PubMed

    Flöckner, H; Braxenthaler, M; Lackner, P; Jaritz, M; Ortner, M; Sippl, M J

    1995-11-01

    The prediction experiment reveals that fold recognition has become a powerful tool in structural biology. We applied our fold recognition technique to 13 target sequences. In two cases, replication terminating protein and prosequence of subtilisin, the predicted structures are very similar to the experimentally determined folds. For the first time, in a public blind test, the unknown structures of proteins have been predicted ahead of experiment to an accuracy approaching molecular detail. In two other cases the approximate folds have been predicted correctly. According to the assessors there were 12 recognizable folds among the target proteins. In our postprediction analysis we find that in 7 cases our fold recognition technique is successful. In several of the remaining cases the predicted folds have interesting features in common with the experimental results. We present our procedure, discuss the results, and comment on several fundamental and technical problems encountered in fold recognition.

  16. A decision aid regarding long-term tube feeding targeting substitute decision makers for cognitively impaired older persons in Japan: A small-scale before-and-after study

    PubMed Central

    2014-01-01

    Background In Japan, there is no decision-making guide regarding long-term tube feeding that specifically targets individuals making decisions on behalf of cognitively impaired older persons (substitute decision makers). The objective of this study was to describe the development and evaluation of such a decision aid. Methods In this before-and-after study, participants comprised substitute decision makers for 13 cognitively impaired inpatients aged 65 years and older who were being considered for placement of a percutaneous endoscopic gastrostomy tube in acute care hospitals and mixed-care hospitals in Japan. Questionnaires were used to compare substitute decision makers’ knowledge, decisional conflict, and predisposition regarding feeding tube placement before and after exposure to a decision aid. The acceptability of the decision aid was also assessed. Paired t-tests were used to compare participants’ knowledge and decisional conflict scores before and after using the decision aid. Results Substitute decision makers showed significantly increased knowledge (P < .001) and decreased decisional conflict (P < .01) regarding long-term tube feeding after using the decision aid. All substitute decision makers found the decision aid helpful and acceptable. Conclusions The decision aid facilitated the decision-making process of substitute decision makers by decreasing decisional conflict and increasing knowledge. PMID:24495735

  17. Drug targeting of HIV-1 RNA.DNA hybrid structures: thermodynamics of recognition and impact on reverse transcriptase-mediated ribonuclease H activity and viral replication.

    PubMed

    Li, Tsai-Kun; Barbieri, Christopher M; Lin, Hsin-Chin; Rabson, Arnold B; Yang, Gengcheng; Fan, Yupeng; Gaffney, Barbara L; Jones, Roger A; Pilch, Daniel S

    2004-08-01

    RNA degradation via the ribonuclease H (RNase H) activity of human immunodeficiency virus type I (HIV-1) reverse transcriptase (RT) is a critical component of the reverse transcription process. In this connection, mutations of RT that inactivate RNase H activity result in noninfectious virus particles. Thus, interfering with the RNase H activity of RT represents a potential vehicle for the inhibition of HIV-1 replication. Here, we demonstrate an approach for inhibiting the RNase H activity of HIV-1 RT by targeting its RNA.DNA hybrid substrates. Specifically, we show that the binding of the 4,5-disubstituted 2-deoxystreptamine aminoglycosides, neomycin, paromomycin, and ribostamycin, to two different chimeric RNA-DNA duplexes, which mimic two distinct intermediates in the reverse transcription process, inhibits specific RT-mediated RNase H cleavage, with this inhibition being competitive in nature. UV melting and isothermal titration calorimetry studies reveal a correlation between the relative binding affinities of the three drugs for each of the chimeric RNA-DNA host duplexes and the relative extents to which the drugs inhibit RT-mediated RNase H cleavage of the duplexes. Significantly, this correlation also extends to the relative efficacies with which the drugs inhibit HIV-1 replication. In the aggregate, our results highlight a potential strategy for AIDS chemotherapy that should not be compromised by the unusual genetic diversity of HIV-1.

  18. HIV / AIDS

    MedlinePlus

    ... Marketing Share this: Main Content Area Understanding HIV/AIDS AIDS was first reported in the United States in ... and has since become a major worldwide epidemic. AIDS is caused by the human immunodeficiency virus, or ...

  19. Clinical determination of target registration error of an image-guided otologic surgical system using patients with bone-anchored hearing aids

    NASA Astrophysics Data System (ADS)

    Balachandran, Ramya; Labadie, Robert F.; Fitzpatrick, J. Michael

    2007-03-01

    Image guidance in otologic surgery has been thwarted by the need for a non-invasive fiducial system with target registration error (TRE) at the inner ear below 1.5mm. We previously presented a fiducial frame for this purpose that attaches to the upper dentition via patient-specific bite blocks and demonstrated a TRE of 0.73mm (+/-0.23mm) on cadaveric skulls. In that study, TRE measurement depended upon placement of bone-implanted, intracranial target fiducials-clearly impossible to repeat clinically. Using cadaveric specimens, we recently presented a validation method based on an auditory implant system (BAHA System® Cochlear Corp., Denver, CO). That system requires a skull-implanted titanium screw behind the ear upon which a bone-anchored hearing aid (BAHA) is mounted. In our validation, we replace the BAHA with a fiducial marker to permit measurement of TRE. That TRE is then used to estimate TRE at an internal point. While the method can be used to determine accuracy at any point within the head, we focus in this study on the inner ear, in particular the cochlea, and we apply the method to patients (N=5). Physical localizations were performed after varying elapsed times since bite-block fabrication, and TRE at the cochlea was estimated. We found TRE to be 0.97mm at the cochlea within one month and 2.5mm after seven months. Thus, while accuracy deteriorates considerably with delays of seven months or more, if this frame is used within one month of the fabrication of the bite-block, it achieves the goal and in fact exhibits submillimetric accuracy.

  20. Abelson tyrosine-protein kinase 1 as principal target for drug discovery against leukemias. Role of the current computer-aided drug design methodologies.

    PubMed

    Speck-Planche, Alejandro; Luan, Feng; Cordeiro, M N D S

    2012-01-01

    The discovery of anti-cancer agents is an area which continues in accelerated expansion. Leukemias (Lkms) are among the most investigated cancers due to its high and dominant prevalence in children. Computer-aided drug design (CADD) methodologies have been extremely important for the discovery of potent anti-Lkms agents, providing essential insights about the molecular patterns which could be involved in the appearance and development of anti-Lkms activity. The present review is focused on the role of the current CADD methodologies for the discovery of anti-Lkms agents with strong emphasis on the in silico prediction of inhibitors against the primary protein associated with the appearance of Lkms: Abelson tyrosine-protein kinase 1 (TPK-ABL1). In order to make a contribution to the field, we also developed a unified ligand-based approach by exploring Quantitative-Structure Activity Relationships (QSAR) studies. Here, we focused on the construction of two multi-targets (mt) QSAR models by employing a large and heterogeneous database of compounds. These models exhibited excellent statistical quality and predictive power to classifying more than 92% of inhibitors/ no inhibitors against seven proteins associated with Lkms, in both training and prediction sets. By using our unified ligand-based approach we identified several fragments as responsible for the anti-Lkms activity through inhibition of proteins, and new molecules were suggested as versatile inhibitors of the seven proteins under study.

  1. The effect of benzyl isothiocyanate and its computer-aided design derivants targeting alkylglycerone phosphate synthase on the inhibition of human glioma U87MG cell line.

    PubMed

    Zhu, Yu; Liu, Anmin; Zhang, Xuebin; Qi, Lisha; Zhang, Ling; Xue, Jing; Liu, Yi; Yang, Ping

    2015-05-01

    Benzyl isothiocyanate (BITC) has been shown to have inhibitory potential for human glioma U87MG cells; however, the effect and mechanism were not fully clear. In the present study, we found that BITC could inhibit U87MG cell proliferation, adhesion, invasion, and vasculogenic mimicry (VM) formation potential and induce oxidative stress, apoptosis, and cell cycle arrest. We also found that the expression of proliferation, invasion, VM oxidative stress, apoptosis, and cell cycle-related gene and the activity of tumor-related signaling pathways, including protein kinase C (PKC) ζ and Akt/nuclear factor-kappa B (NF-κB) pathways, were suppressed by BITC treatment. We also explored the anti-tumor potential of BITC in vivo, and we found that BITC also could regulate the expression of tumor-related gene and angiogenesis in nude mice model. Finally, we optimized the BITC construction targeting alkylglycerone phosphate synthase (AGPS) by computer-aided design, and the derivants also showed anti-tumor potential in vitro.

  2. Solidarity and AIDS: introduction.

    PubMed

    Krieger, N

    1991-01-01

    Perhaps more than any other disease in recent history, AIDS has taught a cruel and crucial lesson: the constraints on our response to this epidemic are as deep as our denial, as entrenched as the inequities that permeate our society, as circumscribed as our knowledge, and as unlimited as our compassion and our commitment to human rights. Elaborating on these themes, the final three articles in this Special Section on AIDS consider three widely divergent yet intimately connected topics: AIDS in Cuba, AIDS in Brazil, and global AIDS prevention in the 1990s. Together, they caution that if we persist in treating AIDS as a problem only of "others," no country will be spared the social and economic devastation that promises to be the cost of our contempt and our folly. Solidarity is not an option; it is a necessity. Without conscious recognition of the worldwide relationship between health, human rights, and social inequalities, our attempts to abate the spread of AIDS--and to ease the suffering that follows in its wake--most surely will fall short of our goals. Finally, as we mourn our dead, we must take to heart the words of Mother Jones, and "fight like hell for living." This is the politics of survival.

  3. Face recognition performance with superresolution.

    PubMed

    Hu, Shuowen; Maschal, Robert; Young, S Susan; Hong, Tsai Hong; Phillips, P Jonathon

    2012-06-20

    With the prevalence of surveillance systems, face recognition is crucial to aiding the law enforcement community and homeland security in identifying suspects and suspicious individuals on watch lists. However, face recognition performance is severely affected by the low face resolution of individuals in typical surveillance footage, oftentimes due to the distance of individuals from the cameras as well as the small pixel count of low-cost surveillance systems. Superresolution image reconstruction has the potential to improve face recognition performance by using a sequence of low-resolution images of an individual's face in the same pose to reconstruct a more detailed high-resolution facial image. This work conducts an extensive performance evaluation of superresolution for a face recognition algorithm using a methodology and experimental setup consistent with real world settings at multiple subject-to-camera distances. Results show that superresolution image reconstruction improves face recognition performance considerably at the examined midrange and close range. PMID:22722306

  4. Face recognition performance with superresolution.

    PubMed

    Hu, Shuowen; Maschal, Robert; Young, S Susan; Hong, Tsai Hong; Phillips, P Jonathon

    2012-06-20

    With the prevalence of surveillance systems, face recognition is crucial to aiding the law enforcement community and homeland security in identifying suspects and suspicious individuals on watch lists. However, face recognition performance is severely affected by the low face resolution of individuals in typical surveillance footage, oftentimes due to the distance of individuals from the cameras as well as the small pixel count of low-cost surveillance systems. Superresolution image reconstruction has the potential to improve face recognition performance by using a sequence of low-resolution images of an individual's face in the same pose to reconstruct a more detailed high-resolution facial image. This work conducts an extensive performance evaluation of superresolution for a face recognition algorithm using a methodology and experimental setup consistent with real world settings at multiple subject-to-camera distances. Results show that superresolution image reconstruction improves face recognition performance considerably at the examined midrange and close range.

  5. Examining the Impact of a Highly Targeted State Administered Merit Aid Program on Brain Drain: Evidence from a Regression Discontinuity Analysis of Missouri's Bright Flight Program

    ERIC Educational Resources Information Center

    Harrington, James R.; Muñoz, José; Curs, Bradley R.; Ehlert, Mark

    2016-01-01

    The adoption of state-funded merit-based aid programs has become increasingly popular among policy-makers, particularly in the southeastern part of the United States. One of the primary rationales of state-funded merit-based aid is to provide scholarships to the best and brightest students as a means to retain high quality human capital in the…

  6. AIDS and the Newborn. Report on a WHO Consultation (Copenhagen, Denmark, April 9-10, 1987). Health for All 2000 Target 4.

    ERIC Educational Resources Information Center

    World Health Organization, Copenhagen (Denmark). Regional Office for Europe.

    Reflecting worldwide concern over the spread of the AIDS epidemic, the Sexuality and Family Planning Unit of the World Health Organization's Regional Office for Europe brought advisors from seven European countries and the United States together to engage in a discussion of AIDS and the newborn, and that consultation forms the basis of this…

  7. A Novel Molecular Recognition Motif Necessary for Targeting Photoactivated Phytochrome Signaling to Specific Basic Helix-Loop-Helix Transcription FactorsW⃞

    PubMed Central

    Khanna, Rajnish; Huq, Enamul; Kikis, Elise A.; Al-Sady, Bassem; Lanzatella, Christina; Quail, Peter H.

    2004-01-01

    The phytochrome (phy) family of sensory photoreceptors (phyA to phyE) in Arabidopsis thaliana control plant developmental transitions in response to informational light signals throughout the life cycle. The photoactivated conformer of the photoreceptor Pfr has been shown to translocate into the nucleus where it induces changes in gene expression by an unknown mechanism. Here, we have identified two basic helix-loop-helix (bHLH) transcription factors, designated PHYTOCHROME-INTERACTING FACTOR5 (PIF5) and PIF6, which interact specifically with the Pfr form of phyB. These two factors cluster tightly with PIF3 and two other phy-interacting bHLH proteins in a phylogenetic subfamily within the large Arabidopsis bHLH (AtbHLH) family. We have identified a novel sequence motif (designated the active phytochrome binding [APB] motif) that is conserved in these phy-interacting AtbHLHs but not in other noninteractors. Using the isolated domain and site-directed mutagenesis, we have shown that this motif is both necessary and sufficient for binding to phyB. Transgenic expression of the native APB-containing AtbHLH protein, PIF4, in a pif4 null mutant, rescued the photoresponse defect in this mutant, whereas mutated PIF4 constructs with site-directed substitutions in conserved APB residues did not. These data indicate that the APB motif is necessary for PIF4 function in light-regulated seedling development and suggest that conformer-specific binding of phyB to PIF4 via the APB motif is necessary for this function in vivo. Binding assays with the isolated APB domain detected interaction with phyB, but none of the other four Arabidopsis phys. Collectively, the data suggest that the APB domain provides a phyB-specific recognition module within the AtbHLH family, thereby conferring photoreceptor target specificity on a subset of these transcription factors and, thus, the potential for selective signal channeling to segments of the transcriptional network. PMID:15486100

  8. AIDS (image)

    MedlinePlus

    AIDS (acquired immune deficiency syndrome) is caused by HIV (human immunodeficiency virus), and is a syndrome that ... life-threatening illnesses. There is no cure for AIDS, but treatment with antiviral medicine can suppress symptoms. ...

  9. Hearing Aids

    MedlinePlus

    ... more in both quiet and noisy situations. Hearing aids help people who have hearing loss from damage ... your doctor. There are different kinds of hearing aids. They differ by size, their placement on or ...

  10. Hearing Aids

    MedlinePlus

    ... type and degree of loss. Are there different styles of hearing aids? Styles of hearing aids Source: NIH/NIDCD Behind-the- ... the ear canal and are available in two styles. The in-the-canal (ITC) hearing aid is ...

  11. Mandarin melody recognition by pediatric cochlear implant recipients.

    PubMed

    Hsiao, Feilin

    2008-01-01

    This study investigated the ability of children with implants who speak Mandarin Chinese, a tonal language, to recognize familiar melodies. It further examined the relative contributions of pitch, rhythm, and lyrics to melody recognition. Two groups of participants (ages 7-15; n = 20 for each group), those with cochlear implants and those with typical hearing, listened to 2 sets (traditional Mandarin children's songs and children's songs from Western cultures translated into Mandarin) of three melodies. These melodies were presented in 3 conditions: (a) melodic contour only (pitches in equal durations); (b) melodic contour with rhythmic patterns; and (c) melodic contour with rhythmic patterns and lyrics. The results indicated that pediatric cochlear implant recipients performed with greater accuracy in melody recognition when lyrics were available. Their scores were significantly lower when melodies containing only pitch features. Providing the rhythmic patterns aided participants' identification of the target melodies, but less so than the lyrics. Applications of findings to aural rehabilitation are discussed.

  12. Domain definition and target classification for CASP6.

    PubMed

    Tress, Michael; Tai, Chin-Hsien; Wang, Guoli; Ezkurdia, Iakes; López, Gonzalo; Valencia, Alfonso; Lee, Byungkook; Dunbrack, Roland L

    2005-01-01

    Assessment of structure predictions in CASP6 was based on single domains isolated from experimentally determined structures, which were categorized into comparative modeling, fold recognition, and new fold targets. Domain definitions were defined upon visual examination of the structures with the aid of automated domain-parsing programs. Domain categorization was determined by comparison of the target structures with those in the Protein Data Bank at the time each target expired and a variety of sequence and structure-based methods to determine potential homologous relationships. PMID:16187342

  13. Human serum albumin supported lipid patterns for the targeted recognition of microspheres coated by membrane based on ss-DNA hybridization

    SciTech Connect

    Zhang Xiaoming; He Qiang; Duan Li; Li Junbai . E-mail: jbli@iccas.ac.cn

    2006-10-27

    Human serum albumin (HSA) patterns have been successfully fabricated for the deposition of lipid bilayer, 1,2-dimyristoyl-sglycerophosphate (DMPA), by making use of the micro-contact printing ({mu}CP) technique and liposome fusion. Confocal laser scanning microscopy (CLSM) results indicate that lipid bilayer has been assembled in HSA patterns with a good stability. Such well-defined lipid patterns formed on HSA surface create possibility to incorporate specific components like channels or receptors for specific recognition. In view of this, microspheres coated with lipid membranes were immobilized in HSA-supported lipid patterns via the hybridization of complementary ss-DNAs. This procedure enables to transfer solid materials to a soft surface through a specific recognition.

  14. Differential cellular recognition pattern to M. tuberculosis targets defined by IFN-γ and IL-17 production in blood from TB + patients from Honduras as compared to health care workers: TB and immune responses in patients from Honduras

    PubMed Central

    2013-01-01

    Background A better understanding of the quality of cellular immune responses directed against molecularly defined targets will guide the development of TB diagnostics and identification of molecularly defined, clinically relevant M.tb vaccine candidates. Methods Recombinant proteins (n = 8) and peptide pools (n = 14) from M. tuberculosis (M.tb) targets were used to compare cellular immune responses defined by IFN-γ and IL-17 production using a Whole Blood Assay (WBA) in a cohort of 148 individuals, i.e. patients with TB + (n = 38), TB- individuals with other pulmonary diseases (n = 81) and individuals exposed to TB without evidence of clinical TB (health care workers, n = 29). Results M.tb antigens Rv2958c (glycosyltransferase), Rv2962c (mycolyltransferase), Rv1886c (Ag85B), Rv3804c (Ag85A), and the PPE family member Rv3347c were frequently recognized, defined by IFN-γ production, in blood from healthy individuals exposed to M.tb (health care workers). A different recognition pattern was found for IL-17 production in blood from M.tb exposed individuals responding to TB10.4 (Rv0288), Ag85B (Rv1886c) and the PPE family members Rv0978c and Rv1917c. Conclusions The pattern of immune target recognition is different in regard to IFN-γ and IL-17 production to defined molecular M.tb targets in PBMCs from individuals frequently exposed to M.tb. The data represent the first mapping of cellular immune responses against M.tb targets in TB patients from Honduras. PMID:23497342

  15. HIV / AIDS and tourism.

    PubMed

    Forsythe, S

    1999-01-01

    Since it tends to be significantly affected by HIV/AIDS, the tourism sector is a likely target for HIV/AIDS interventions in many countries. The tourist industry is at particular risk from the pandemic because of the mobility of the work force, the presence of sex tourists, and the heavy reliance of many countries upon tourism revenues. Indeed, tourism is one of the largest and fastest growing industries in many countries. Some people have speculated that potential tourists' fear of AIDS could discourage them from visiting certain countries, while others have even suggested that tourism should be discouraged because the industry contributes to the spread of HIV/AIDS. When traveling, tourists often take risks that they would not take at home. They tend to drink more, use drugs more, and be generally more adventurous while on holiday. Such adventures often include taking sexual risks. When tourists have sex with prostitutes, hotel staff, and others in the local population, a bridge can be created for HIV to cross back and forth between the tourist's home country and the tourist destination. The author reviews selected studies on the relationship between HIV/AIDS and tourism. Overall, the existing literature offers no definitive evidence that AIDS has had any lasting impact upon the tourism industry anywhere in the world. Rather, promoting a healthy tourism industry and HIV/AIDS prevention are likely complementary in many ways. PMID:12349153

  16. HIV / AIDS and tourism.

    PubMed

    Forsythe, S

    1999-01-01

    Since it tends to be significantly affected by HIV/AIDS, the tourism sector is a likely target for HIV/AIDS interventions in many countries. The tourist industry is at particular risk from the pandemic because of the mobility of the work force, the presence of sex tourists, and the heavy reliance of many countries upon tourism revenues. Indeed, tourism is one of the largest and fastest growing industries in many countries. Some people have speculated that potential tourists' fear of AIDS could discourage them from visiting certain countries, while others have even suggested that tourism should be discouraged because the industry contributes to the spread of HIV/AIDS. When traveling, tourists often take risks that they would not take at home. They tend to drink more, use drugs more, and be generally more adventurous while on holiday. Such adventures often include taking sexual risks. When tourists have sex with prostitutes, hotel staff, and others in the local population, a bridge can be created for HIV to cross back and forth between the tourist's home country and the tourist destination. The author reviews selected studies on the relationship between HIV/AIDS and tourism. Overall, the existing literature offers no definitive evidence that AIDS has had any lasting impact upon the tourism industry anywhere in the world. Rather, promoting a healthy tourism industry and HIV/AIDS prevention are likely complementary in many ways.

  17. Strategy of integrated evaluation on treatment of traditional Chinese medicine as 'interaction of system to system' and establishment of novel fuzzy target contribution recognition with herb-pairs, a case study on Astragali Radix-Fructus Corni.

    PubMed

    Duan, Yu; Pei, Ke; Cai, Hao; Tu, Sicong; Cheng, Xinwei; Zhang, Zhengwei; Fan, Kailei; Qiao, Fengxian; Qin, Kunming; Cai, Baochang

    2016-10-15

    To date, in the struggle against diseases and the development of TCM, what we lack is wisdom rather than knowledge. Studies on pharmacology of traditional Chinese medicine are facing critical challenges on how to select the proper parameters or targets to represent the pharmacological evaluation system. With seven steps of optimized modules established by ourselves, we can re-evaluate TCM in a panorama view with a proper pharmacological evaluation system. In this article, with the treatment of TCM as 'interaction of system to system', a novel and generally applicable approach called fuzzy target contribution recognition was established and agents from Astragali Radix-Fructus Corni in resisting diabetic nephropathy were successfully discovered for the first time. CG6, a promising agent from this herb-pair on the treatment of diabetic nephropathy, was finally acquired and its possible molecular mechanism was explored through a nuclear factor erythroid 2-Like 2 (NFE2L2) activation-dependent pathway.

  18. Children's Aid and the Schools.

    ERIC Educational Resources Information Center

    Bridgeland, William M.; Duane, Edward A.

    In Ontario, Canada, the agency which has the foremost obligation for the discovery and amelioration of child abuse and neglect is Children's Aid. Elementary schools are the target of much child-abuse detection. This article develops the perceptions of a representative group of 10 workers in Children's Aid on the schools relative to child abuse.…

  19. FLIR target screening

    NASA Technical Reports Server (NTRS)

    Aggarwal, R.

    1982-01-01

    Methods for the segmentation and recognition of individual targets sensed with forward looking infrared detectors are discussed. Particular attention is given to an adaptive multi-scenario target screener.

  20. Financial Aid.

    ERIC Educational Resources Information Center

    Graves, Mary A.

    This workbook assists college and vocational school bound American Indian students in determining their financial needs and in locating sources of financial aid. A checklist helps students assess the state of their knowledge of financial programs; a glossary defines terms pertinent to the realm of financial aid (i.e., graduate study programs,…

  1. Teaching AIDS.

    ERIC Educational Resources Information Center

    Tonks, Douglas

    This book presents a curriculum to educate students about the risk of AIDS and HIV infection. The opening chapters of the book presents a discussion of: how teachers can create an environment of support for an AIDS education program; the political and educational implications of winning principal, district, and parental support for an AIDS…

  2. Reader error, object recognition, and visual search

    NASA Astrophysics Data System (ADS)

    Kundel, Harold L.

    2004-05-01

    Small abnormalities such as hairline fractures, lung nodules and breast tumors are missed by competent radiologists with sufficient frequency to make them a matter of concern to the medical community; not only because they lead to litigation but also because they delay patient care. It is very easy to attribute misses to incompetence or inattention. To do so may be placing an unjustified stigma on the radiologists involved and may allow other radiologists to continue a false optimism that it can never happen to them. This review presents some of the fundamentals of visual system function that are relevant to understanding the search for and the recognition of small targets embedded in complicated but meaningful backgrounds like chests and mammograms. It presents a model for visual search that postulates a pre-attentive global analysis of the retinal image followed by foveal checking fixations and eventually discovery scanning. The model will be used to differentiate errors of search, recognition and decision making. The implications for computer aided diagnosis and for functional workstation design are discussed.

  3. Pattern recognition receptors in microbial keratitis.

    PubMed

    Taube, M-A; del Mar Cendra, M; Elsahn, A; Christodoulides, M; Hossain, P

    2015-11-01

    Microbial keratitis is a significant cause of global visual impairment and blindness. Corneal infection can be caused by a wide variety of pathogens, each of which exhibits a range of mechanisms by which the immune system is activated. The complexity of the immune response to corneal infection is only now beginning to be elucidated. Crucial to the cornea's defences are the pattern-recognition receptors: Toll-like and Nod-like receptors and the subsequent activation of inflammatory pathways. These inflammatory pathways include the inflammasome and can lead to significant tissue destruction and corneal damage, with the potential for resultant blindness. Understanding the immune mechanisms behind this tissue destruction may enable improved identification of therapeutic targets to aid development of more specific therapies for reducing corneal damage in infectious keratitis. This review summarises current knowledge of pattern-recognition receptors and their downstream pathways in response to the major keratitis-causing organisms and alludes to potential therapeutic approaches that could alleviate corneal blindness.

  4. Structural basis for the recognition of mycolic acid precursors by KasA, a condensing enzyme and drug target from Mycobacterium tuberculosis.

    PubMed

    Schiebel, Johannes; Kapilashrami, Kanishk; Fekete, Agnes; Bommineni, Gopal R; Schaefer, Christin M; Mueller, Martin J; Tonge, Peter J; Kisker, Caroline

    2013-11-22

    The survival of Mycobacterium tuberculosis depends on mycolic acids, very long α-alkyl-β-hydroxy fatty acids comprising 60-90 carbon atoms. However, despite considerable efforts, little is known about how enzymes involved in mycolic acid biosynthesis recognize and bind their hydrophobic fatty acyl substrates. The condensing enzyme KasA is pivotal for the synthesis of very long (C38-42) fatty acids, the precursors of mycolic acids. To probe the mechanism of substrate and inhibitor recognition by KasA, we determined the structure of this protein in complex with a mycobacterial phospholipid and with several thiolactomycin derivatives that were designed as substrate analogs. Our structures provide consecutive snapshots along the reaction coordinate for the enzyme-catalyzed reaction and support an induced fit mechanism in which a wide cavity is established through the concerted opening of three gatekeeping residues and several α-helices. The stepwise characterization of the binding process provides mechanistic insights into the induced fit recognition in this system and serves as an excellent foundation for the development of high affinity KasA inhibitors. PMID:24108128

  5. Structural Basis for the Recognition of Mycolic Acid Precursors by KasA, a Condensing Enzyme and Drug Target from Mycobacterium Tuberculosis *

    PubMed Central

    Schiebel, Johannes; Kapilashrami, Kanishk; Fekete, Agnes; Bommineni, Gopal R.; Schaefer, Christin M.; Mueller, Martin J.; Tonge, Peter J.; Kisker, Caroline

    2013-01-01

    The survival of Mycobacterium tuberculosis depends on mycolic acids, very long α-alkyl-β-hydroxy fatty acids comprising 60–90 carbon atoms. However, despite considerable efforts, little is known about how enzymes involved in mycolic acid biosynthesis recognize and bind their hydrophobic fatty acyl substrates. The condensing enzyme KasA is pivotal for the synthesis of very long (C38–42) fatty acids, the precursors of mycolic acids. To probe the mechanism of substrate and inhibitor recognition by KasA, we determined the structure of this protein in complex with a mycobacterial phospholipid and with several thiolactomycin derivatives that were designed as substrate analogs. Our structures provide consecutive snapshots along the reaction coordinate for the enzyme-catalyzed reaction and support an induced fit mechanism in which a wide cavity is established through the concerted opening of three gatekeeping residues and several α-helices. The stepwise characterization of the binding process provides mechanistic insights into the induced fit recognition in this system and serves as an excellent foundation for the development of high affinity KasA inhibitors. PMID:24108128

  6. Perceptions of Prostate Cancer Screening Controversy and Informed Decision Making: Implications for Development of a Targeted Decision Aid for Unaffected Male First-Degree Relatives

    PubMed Central

    Gwede, Clement K.; Davis, Stacy N.; Wilson, Shaenelle; Patel, Mitul; Vadaparampil, Susan T.; Meade, Cathy D.; Rivers, Brian M.; Yu, Daohai; Torres-Roca, Javier; Heysek, Randy; Spiess, Philippe E.; Pow-Sang, Julio; Jacobsen, Paul

    2014-01-01

    Purpose First-degree relatives (FDRs) of prostate cancer (PC) patients should consider multiple concurrent personal risk factors when engaging in informed decision making (IDM) about PC screening. This study assessed perceptions of IDM recommendations and risk-appropriate strategies for IDM among FDRs of varied race/ethnicity. Design A cross-sectional, qualitative Setting Study setting was a cancer center in southwest Florida. Participants The study comprised 44 participants (24 PC patients and 20 unaffected FDRs). Method Focus groups and individual interviews were conducted and analyzed using content analysis and constant comparison methods. Results Patients and FDRs found the PC screening debate and IDM recommendations to be complex and counterintuitive. They overwhelmingly believed screening saves lives and does not have associated harms. There was a strongly expressed need to improve communication between patients and FDRs. A single decision aid that addresses the needs of all FDRs, rather than separating by race/ethnicity, was recommended as sufficient by study participants. These perspectives guided the development of an innovative decision aid that deconstructs the screening controversy and IDM processes into simpler concepts and provides step-by-step strategies for FDRs to engage in IDM. Conclusion Implementing IDM among FDRs is challenging because the IDM paradigm departs from historical messages promoting routine screening. These contradictions should be recognized and addressed for men to participate effectively in IDM. A randomized pilot study evaluating outcomes of the resulting decision aid is underway. PMID:24968183

  7. Live-cell single-molecule tracking reveals co-recognition of H3K27me3 and DNA targets polycomb Cbx7-PRC1 to chromatin

    PubMed Central

    Zhen, Chao Yu; Tatavosian, Roubina; Huynh, Thao Ngoc; Duc, Huy Nguyen; Das, Raibatak; Kokotovic, Marko; Grimm, Jonathan B; Lavis, Luke D; Lee, Jun; Mejia, Frances J; Li, Yang; Yao, Tingting; Ren, Xiaojun

    2016-01-01

    The Polycomb PRC1 plays essential roles in development and disease pathogenesis. Targeting of PRC1 to chromatin is thought to be mediated by the Cbx family proteins (Cbx2/4/6/7/8) binding to histone H3 with a K27me3 modification (H3K27me3). Despite this prevailing view, the molecular mechanisms of targeting remain poorly understood. Here, by combining live-cell single-molecule tracking (SMT) and genetic engineering, we reveal that H3K27me3 contributes significantly to the targeting of Cbx7 and Cbx8 to chromatin, but less to Cbx2, Cbx4, and Cbx6. Genetic disruption of the complex formation of PRC1 facilitates the targeting of Cbx7 to chromatin. Biochemical analyses uncover that the CD and AT-hook-like (ATL) motif of Cbx7 constitute a functional DNA-binding unit. Live-cell SMT of Cbx7 mutants demonstrates that Cbx7 is targeted to chromatin by co-recognizing of H3K27me3 and DNA. Our data suggest a novel hierarchical cooperation mechanism by which histone modifications and DNA coordinate to target chromatin regulatory complexes. DOI: http://dx.doi.org/10.7554/eLife.17667.001 PMID:27723458

  8. Insight into the recognition, binding, and reactivity of catalytic metallodrugs targeting stem loop IIb of hepatitis C IRES RNA.

    PubMed

    Bradford, Seth S; Ross, Martin James; Fidai, Insiya; Cowan, James A

    2014-06-01

    The complex Cu-GGHYrFK-amide (1-Cu) was previously reported as a novel metallotherapeutic that catalytically inactivates stem loop IIb (SLIIb) of the hepatitis C virus (HCV) internal ribosomal entry site (IRES) RNA and demonstrates significant antiviral activity in a cellular HCV replicon assay. Herein we describe additional studies focused on understanding the cleavage mechanism as well as the relationship of catalyst configuration to structural recognition and site-selective cleavage of the structured RNA motif. These are advanced by use of a combination of MALDI-TOF mass spectrometry, melting temperature determinations, and computational analysis to develop a structural model for binding and reactivity toward SLIIb of the IRES RNA. In addition, the binding, reactivity, and structural chemistry of the all-D-amino acid form of this metallopeptide, complex 2-Cu, are reported and compared with those of complex 1-Cu. In vitro RNA binding and cleavage assays for complex 2-Cu show a KD value of 76 ± 3 nM, and Michaelis-Menten parameters of kcat =0.14 ± 0.01 min(-1) and KM =7.9 ± 1.2 μM, with a turnover number exceeding 40. In a luciferase-based cellular replicon assay Cu-GGhyrfk-amide shows activity similar to that of the 1-Cu parent peptide, with an IC50 value of 1.9 ± 0.4 μM and cytotoxicity exceeding 100 μM. RT-PCR experiments confirm a significant decrease in HCV RNA levels in replicon assays for up to nine days when treated with complex 1-Cu in three-day dosing increments. This study shows the influence that the α-carbon stereocenter has for this new class of compounds, while detailed mass spectrometry and computational analyses provide new insight into the mechanisms of recognition, binding, and reactivity.

  9. Insight into the recognition, binding, and reactivity of catalytic metallodrugs targeting stem loop IIb of hepatitis C IRES RNA.

    PubMed

    Bradford, Seth S; Ross, Martin James; Fidai, Insiya; Cowan, James A

    2014-06-01

    The complex Cu-GGHYrFK-amide (1-Cu) was previously reported as a novel metallotherapeutic that catalytically inactivates stem loop IIb (SLIIb) of the hepatitis C virus (HCV) internal ribosomal entry site (IRES) RNA and demonstrates significant antiviral activity in a cellular HCV replicon assay. Herein we describe additional studies focused on understanding the cleavage mechanism as well as the relationship of catalyst configuration to structural recognition and site-selective cleavage of the structured RNA motif. These are advanced by use of a combination of MALDI-TOF mass spectrometry, melting temperature determinations, and computational analysis to develop a structural model for binding and reactivity toward SLIIb of the IRES RNA. In addition, the binding, reactivity, and structural chemistry of the all-D-amino acid form of this metallopeptide, complex 2-Cu, are reported and compared with those of complex 1-Cu. In vitro RNA binding and cleavage assays for complex 2-Cu show a KD value of 76 ± 3 nM, and Michaelis-Menten parameters of kcat =0.14 ± 0.01 min(-1) and KM =7.9 ± 1.2 μM, with a turnover number exceeding 40. In a luciferase-based cellular replicon assay Cu-GGhyrfk-amide shows activity similar to that of the 1-Cu parent peptide, with an IC50 value of 1.9 ± 0.4 μM and cytotoxicity exceeding 100 μM. RT-PCR experiments confirm a significant decrease in HCV RNA levels in replicon assays for up to nine days when treated with complex 1-Cu in three-day dosing increments. This study shows the influence that the α-carbon stereocenter has for this new class of compounds, while detailed mass spectrometry and computational analyses provide new insight into the mechanisms of recognition, binding, and reactivity. PMID:24756921

  10. Hearing Aid

    MedlinePlus

    ... and Food and Drug Administration Staff FDA permits marketing of new laser-based hearing aid with potential ... feeds Follow FDA on Twitter Follow FDA on Facebook View FDA videos on YouTube View FDA photos ...

  11. Recognition of HLA-A2 mutant and variant target cells by an HLA-A2 allospecific human cytotoxic T lymphocyte line.

    PubMed

    Ware, C F; Krangel, M S; Pious, D; Burakoff, S J; Strominger, J L

    1983-09-01

    HLA-A2 specific human cytotoxic T lymphocytes (CTL) cell lines have been developed using T cell growth factor and coculture of peripheral blood lymphocytes with selected allogeneic target cell lines. The CTL-8 line showed specificity for human leukocyte antigens (HLA)-A2 bearing target cells after 5 weeks in culture when tested against a panel of 14 lymphoblastoid cell lines in a 51Chromium (51Cr) release assay. Purified anti-human leukocyte antigens (HLA) monoclonal antibodies W6/32 and PA2.1 inhibited cytolysis by 85% and 60%, respectively. The CTL-8 line lysed non-HLA-A2 target cells in the presence of lectins concanavalin A (Con A) or phytohemagglutinin-P lectin (PHA-P) indicating the specificity of cytolysis was not due to nonspecific resistance of target cells to the CTL-lytic mechanism. The T5-1 HLA-A2 mutant cell series were tested as targets for the CTL-8 line. Cell clones 8.18.1, 8.21.1 and 8.6.1, which express altered HLA-A2 molecules as determined by their decreased reactivity with allospecific monoclonal antibodies, were lysed by the CTL-8 line as efficiently as the T5-1 wild type. These cell lines also acted as efficient cold target competitors for a normal HLA-A2 target cell. The 8.14.1 cell clone expressed a lower amount of HLA-A2 alloantigen and showed a corresponding decreased reactivity with CTL-8 in direct cytolytic and cold target competitive inhibition assays. In contrast, the M7 and DK1 HLA-A2 variant cell lines, which express normal HLA-A2 serological determinants, were inefficiently lysed by CTL-8 and did not act as competitive inhibitors of normal HLA-A2 target cells. These results support the concept that the alloantigenic determinant(s) recognized by T cells and antibodies occur at separate regions on the HLA-A2 molecule. PMID:6193184

  12. Recognition of a common rDNA target site in archaea and eukarya by analogous LAGLIDADG and His-Cys box homing endonucleases.

    PubMed

    Nomura, Norimichi; Nomura, Yayoi; Sussman, Django; Klein, Daniel; Stoddard, Barry L

    2008-12-01

    The presence of a homing endonuclease gene (HEG) within a microbial intron or intein empowers the entire element with the ability to invade genomic targets. The persistence of a homing endonuclease lineage depends in part on conservation of its DNA target site. One such rDNA sequence has been invaded both in archaea and in eukarya, by LAGLIDADG and His-Cys box homing endonucleases, respectively. The bases encoded by this target include a universally conserved ribosomal structure, termed helix 69 (H69) in the large ribosomal subunit. This region forms the 'B2a' intersubunit bridge to the small ribosomal subunit, contacts bound tRNA in the A- and P-sites, and acts as a trigger for ribosome disassembly through its interactions with ribosome recycling factor. We have determined the DNA-bound structure and specificity profile of an archaeal LAGLIDADG homing endonuclease (I-Vdi141I) that recognizes this target site, and compared its specificity with the analogous eukaryal His-Cys box endonuclease I-PpoI. These homodimeric endonuclease scaffolds have arrived at similar specificity profiles across their common biological target and analogous solutions to the problem of accommodating conserved asymmetries within the DNA sequence, but with differences at individual base pairs that are fine-tuned to the sequence conservation of archaeal versus eukaryal ribosomes. PMID:18984620

  13. Antibody-Hapten Recognition at the Surface of Functionalized Liposomes Studied by SPR: Steric Hindrance of Pegylated Phospholipids in Stealth Liposomes Prepared for Targeted Radionuclide Delivery

    PubMed Central

    Botosoa, Eliot. P.; Maillasson, Mike; Mougin-Degraef, Marie; Remaud-Le Saëc, Patricia; Gestin, Jean-François; Jacques, Yannick; Barbet, Jacques; Faivre-Chauvet, Alain

    2011-01-01

    Targeted PEGylated liposomes could increase the amount of drugs or radionuclides delivered to tumor cells. They show favorable stability and pharmacokinetics, but steric hindrance of the PEG chains can block the binding of the targeting moiety. Here, specific interactions between an antihapten antibody (clone 734, specific for the DTPA-indium complex) and DTPA-indium-tagged liposomes were characterized by surface plasmon resonance (SPR). Non-PEGylated liposomes fused on CM5 chips whereas PEGylated liposomes did not. By contrast, both PEGylated and non-PEGylated liposomes attached to L1 chips without fusion. SPR binding kinetics showed that, in the absence of PEG, the antibody binds the hapten at the surface of lipid bilayers with the affinity of the soluble hapten. The incorporation of PEGylated lipids hinders antibody binding to extents depending on PEGylated lipid fraction and PEG molecular weight. SPR on immobilized liposomes thus appears as a useful technique to optimize formulations of liposomes for targeted therapy. PMID:21490749

  14. AIDS lymphomas.

    PubMed

    Middleton, G W; Lau, R K

    1992-01-01

    Chronically immunosuppressed individuals are susceptible to lymphoreticular tumors. Up to 15% of patients with congenital deficiencies such as ataxia=telangiectasia may develop malignancies, mainly high-grade B cell non=Hodgkin's lymphomas (NHLs). AIDS lymphomas are comprised of NHLs including Burkitt's lymphoma (BL) and primary cerebral lymphomas (PCLs). Almost 3% of all AIDS patients (2824 of 97,258 cases) developed NHL. Epstein-Barr virus (EBV) as a co-factor in AIDS lymphomagenesis has been studied: in 12 cases of 24 AIDS lymphomas EBV by DNA in situ hybridization was found. In an analysis of 6 primary cerebral lymphomas, .5 were positive for EBV DNA by Southern blotting. In Burkitt's lymphoma the characteristic genetic alteration affects the c-myc oncogene. In 1/3 of BL p53 mutations were found but none in the 43 NHLs suggesting that p53 mutations and c-myc activation act synergistically in the pathogenesis of these tumors. Cytotoxic agents dideoxyinosine, dideoxycytosine, and zidovudine may cause secondary neoplasia. 8 of 55 AIDS patients under zidovudine treatment developed high-grade lymphoma 23.8 months subsequently; recently doses were reduced. PCL was found in 21 of 90 patients. A 5.2 months survival was associated with combined treatment with cyclophosphamide, Oncovin (vincristine), methotrexate, etoposide, and cytosine arabinoside compared with 11.3 months with chemotherapy. Colony-stimulating factors (CSFs) alleviate drug-induced myelotoxicity and zidovudine-induced neutropenia, however, l8 of 11 patients receiving granulocyte-macrophage CSF developed hematological toxicity. Interleukine-2 produced by T-helper cells enhancing tumor cells cytotoxicity has been used in AIDS-associated cryptosporidial diarrhea and in 4 patients with AIDS lymphoma with modest response, but its stimulation of the HIV-infected substrate may increase viral proliferation.

  15. A Study of the Combined Use of a Hearing Aid and Tactual Aid in an Adult with Profound Hearing Loss

    ERIC Educational Resources Information Center

    Reed, Charlotte M.; Delhorne, Lorraine A.

    2006-01-01

    This study examined the benefits of the combined used of a hearing aid and tactual aid to supplement lip-reading in the reception of speech and for the recognition of environmental sounds in an adult with profound hearing loss. Speech conditions included lip-reading alone (L), lip-reading + tactual aid (L+TA) lip-reading + hearing aid (L+HA) and…

  16. Confronting AIDS.

    PubMed

    Squire, L

    1998-03-01

    By 2020, HIV/AIDS will be the leading infectious killer of young and middle-aged adults in the developing world. Past gains in life expectancy are already being eroded in some countries. Millions of lives can, however, be saved if developing country governments, the international community, and nongovernmental organizations act now. Although more than 11 million people have already died of AIDS, 2.3 billion people live in developing countries in which the disease has not yet spread beyond certain risk groups. If the spread of HIV is checked, the quality of care available to people who are infected with HIV will probably be better than it would be in the context of a full-blown AIDS epidemic. However, while governments need to respond urgently to HIV/AIDS, using resources to help people with AIDS will reduce the resources available for other investments, such as child education, providing safe drinking water, and building roads. Economics can help governments set priorities as they decide how best to allocate their available resources. Externalities, public goods, and redistribution are discussed. All countries will need to use some combination of preventive and coping measures. PMID:12293445

  17. ESEA Title I: Instructional Aides Program.

    ERIC Educational Resources Information Center

    Lile, Kurt; And Others

    The Title I Program in the Fremont Unified School District is located at two target schools. Currently there are 39 instructional aides employed. Aides were recruited through letters to parents and notices on shopping center bulletin boards in the target area. A committee including the principals of the two schools, the resource teachers, and a…

  18. "Value Added" Modern Languages Teaching in the Classroom: An Investigation into How Teachers' Use of Classroom Target Language Can Aid Pupils' Communication Skills

    ERIC Educational Resources Information Center

    Crichton, Hazel

    2009-01-01

    This paper presents some of the preliminary findings of a study into modern languages (ML) learning in five Scottish secondary schools. Five ML teachers were observed and audio-recorded over a period of several weeks while teaching their third-year classes (pupils aged 14-15 years). All the teachers used the target language extensively in their…

  19. On the use of double FLP recognition targets (FRTs) in the LTR of retroviruses for the construction of high producer cell lines.

    PubMed Central

    Karreman, S; Hauser, H; Karreman, C

    1996-01-01

    A pilot experiment for the construction of a hamster derived, high producer cell line using site specific recombination is described. In the experiment chromosomal loci with intrinsic high expression characteristics were sought via infection with a retroviral construct, containing double FRT sites and subsequent screening for overproduction of an encoded markergene. These sites were then targeted with a second vector, that recombined via the FLP/FRT system from Saccharomyces cerevisiae yielding cells that had the second construct at exactly the same position as the first. By using retroviral vectors with double and single FRT sites, respectively, stable clones can be created that can no longer be excised with FLP. PMID:8649977

  20. Rat pristanoyl-CoA oxidase. cDNA cloning and recognition of its C-terminal (SQL) by the peroxisomal-targeting signal 1 receptor.

    PubMed

    Vanhooren, J C; Fransen, M; de Béthune, B; Baumgart, E; Baes, M; Torrekens, S; Van Leuven, F; Mannaerts, G P; Van Veldhoven, P P

    1996-07-15

    The composite pristanoyl-CoA oxidase cDNA sequence, derived from two overlapping clones from a rat liver cDNA library and a 5'-RACE (rapid amplification of cDNA ends) PCR fragment, consisted of 2600 bases and contained an open reading frame of 2100 bases, encoding a protein of 700 amino acids with a calculated molecular mass of 78445 Da. This value is somewhat larger than the reported molecular mass of 70 kDa as determined earlier by SDS-gel electrophoresis. The amino acid identity with rat palmitoyl-CoA oxidase was rather low (28%) and barely higher than that with the yeast acyl-CoA oxidases (20%), suggesting that the palmitoyl-CoA oxidase/pristanoyl-CoA oxidase duplication occurred early in evolution. The carboxy-terminal tripeptide of pristanoyl-CoA oxidase was SQL. In vitro studies with the bacterially expressed human peroxisomal-targeting signal-1 import receptor indicated that SQL functions as a peroxisome-targeting signal. Northern analysis of tissues from control and clofibrate treated rats demonstrated that the pristanoyl-CoA oxidase gene is transcribed in liver and extrahepatic tissues and that transcription is not enhanced by treatment of rats with peroxisome proliferators. No mRNA could be detected by northern analysis of human tissues, suggesting that the human pristanoyl-CoA oxidase gene, if present, is only poorly or not transcribed.

  1. Classroom Aids

    ERIC Educational Resources Information Center

    Science Activities: Classroom Projects and Curriculum Ideas, 2007

    2007-01-01

    This article describes 6 aids for science instruction, including (1) the use of fudge to represent lava; (2) the "Living by Chemistry" program, designed to make high school chemistry more accessible to a diverse pool of students without sacrificing content; (3) NOAA and NSTA's online coral reef teaching tool, a new web-based "science toolbox" for…

  2. Dietitian Aide.

    ERIC Educational Resources Information Center

    Texas Tech. Univ., Lubbock. School of Home Economics.

    This course of study for the dietitian aide is one of a series available for use by teacher-coordinators and students in Grade 11 and 12 home economics cooperative education programs. Based on job analysis interviews with health care facilities personnel, this course was prepared by teachers and Instructional Materials Center staff, field-tested,…

  3. Floriculture Aide.

    ERIC Educational Resources Information Center

    Martin, Joyce; Looney, Era

    Designed for use in a self-paced, open-entry/open-exit vocational training program for a floriculture aide, this program guide is one of six for teachers of adult women offenders from a correctional institution. Module topic outlines and sample lesson plans are presented on eleven topics: occupational opportunities in the retail florist industry;…

  4. Visibility aids for pedestrians and cyclists: a systematic review of randomised controlled trials.

    PubMed

    Kwan, Irene; Mapstone, James

    2004-05-01

    This study aims to quantify the effect of visibility aids on the occurrence of pedestrian and cyclist-motor vehicle collisions and injuries, and drivers' responses in detection and recognition. Trial reports were systematically reviewed according to predefined eligibility criteria, including randomised controlled trials or controlled before-and-after trials comparing visibility aids and no visibility aids, and of different visibility aids on pedestrian and cyclist safety, and drivers' responses in detection and recognition. This included trials in which the order of interventions was randomised, or balanced using a Latin square design. Two reviewers independently assessed validity of trials and abstracted data. The main outcome measures were pedestrian and cyclist-motor vehicle collisions and injuries, and drivers'/observers' responses in the detection and recognition time, distance and frequency. No trials which assessed the effect of visibility aids on pedestrian and cyclist-motor vehicle collisions and injuries were identified. Twelve trials examined the effectiveness of daytime visibility aids and 25 trials on night time visibility aids, including 882 participants. Drivers' and observers' detection and recognition improved with visibility aids. For daytime, fluorescent materials in yellow, red and orange colours enhanced detection and recognition. "Biomotion" markings enhanced recognition. Substantial heterogeneity between the trials limits the possibility for meta-analysis. Visibility aids have the potential to improve detection and recognition and would merit further development to gain public acceptance. However, the impact of visibility aids on pedestrian and cyclist safety is unknown and needs to be determined. PMID:15003574

  5. Improved design of hammerhead ribozyme for selective digestion of target RNA through recognition of site-specific adenosine-to-inosine RNA editing

    PubMed Central

    Fukuda, Masatora; Kurihara, Kei; Yamaguchi, Shota; Oyama, Yui; Deshimaru, Masanobu

    2014-01-01

    Adenosine-to-inosine (A-to-I) RNA editing is an endogenous regulatory mechanism involved in various biological processes. Site-specific, editing-state–dependent degradation of target RNA may be a powerful tool both for analyzing the mechanism of RNA editing and for regulating biological processes. Previously, we designed an artificial hammerhead ribozyme (HHR) for selective, site-specific RNA cleavage dependent on the A-to-I RNA editing state. In the present work, we developed an improved strategy for constructing a trans-acting HHR that specifically cleaves target editing sites in the adenosine but not the inosine state. Specificity for unedited sites was achieved by utilizing a sequence encoding the intrinsic cleavage specificity of a natural HHR. We used in vitro selection methods in an HHR library to select for an extended HHR containing a tertiary stabilization motif that facilitates HHR folding into an active conformation. By using this method, we successfully constructed highly active HHRs with unedited-specific cleavage. Moreover, using HHR cleavage followed by direct sequencing, we demonstrated that this ribozyme could cleave serotonin 2C receptor (HTR2C) mRNA extracted from mouse brain, depending on the site-specific editing state. This unedited-specific cleavage also enabled us to analyze the effect of editing state at the E and C sites on editing at other sites by using direct sequencing for the simultaneous quantification of the editing ratio at multiple sites. Our approach has the potential to elucidate the mechanism underlying the interdependencies of different editing states in substrate RNA with multiple editing sites. PMID:24448449

  6. Improved design of hammerhead ribozyme for selective digestion of target RNA through recognition of site-specific adenosine-to-inosine RNA editing.

    PubMed

    Fukuda, Masatora; Kurihara, Kei; Yamaguchi, Shota; Oyama, Yui; Deshimaru, Masanobu

    2014-03-01

    Adenosine-to-inosine (A-to-I) RNA editing is an endogenous regulatory mechanism involved in various biological processes. Site-specific, editing-state-dependent degradation of target RNA may be a powerful tool both for analyzing the mechanism of RNA editing and for regulating biological processes. Previously, we designed an artificial hammerhead ribozyme (HHR) for selective, site-specific RNA cleavage dependent on the A-to-I RNA editing state. In the present work, we developed an improved strategy for constructing a trans-acting HHR that specifically cleaves target editing sites in the adenosine but not the inosine state. Specificity for unedited sites was achieved by utilizing a sequence encoding the intrinsic cleavage specificity of a natural HHR. We used in vitro selection methods in an HHR library to select for an extended HHR containing a tertiary stabilization motif that facilitates HHR folding into an active conformation. By using this method, we successfully constructed highly active HHRs with unedited-specific cleavage. Moreover, using HHR cleavage followed by direct sequencing, we demonstrated that this ribozyme could cleave serotonin 2C receptor (HTR2C) mRNA extracted from mouse brain, depending on the site-specific editing state. This unedited-specific cleavage also enabled us to analyze the effect of editing state at the E and C sites on editing at other sites by using direct sequencing for the simultaneous quantification of the editing ratio at multiple sites. Our approach has the potential to elucidate the mechanism underlying the interdependencies of different editing states in substrate RNA with multiple editing sites.

  7. Emotion Recognition in Children and Adolescents with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Kuusikko, Sanna; Haapsamo, Helena; Jansson-Verkasalo, Eira; Hurtig, Tuula; Mattila, Marja-Leena; Ebeling, Hanna; Jussila, Katja; Bolte, Sven; Moilanen, Irma

    2009-01-01

    We examined upper facial basic emotion recognition in 57 subjects with autism spectrum disorders (ASD) (M = 13.5 years) and 33 typically developing controls (M = 14.3 years) by using a standardized computer-aided measure (The Frankfurt Test and Training of Facial Affect Recognition, FEFA). The ASD group scored lower than controls on the total…

  8. Suggested Curriculum for Distance Vision Training with Optical Aids.

    ERIC Educational Resources Information Center

    Wiener, William; Vopata, Alvin

    1980-01-01

    The article describes a sequential training curriculum in the use of telescopic visual aids. The curriculum covers 29 topics, including aid maintenance, holding aid properly, focusing, scanning, target location, tracking, aid use for city bus travel, in a shopping center, and in a fast food type restaurant. (Author/SBH)

  9. Targeted versus tailored multimedia patient engagement to enhance depression recognition and treatment in primary care: randomized controlled trial protocol for the AMEP2 study

    PubMed Central

    2013-01-01

    Background Depression in primary care is common, yet this costly and disabling condition remains underdiagnosed and undertreated. Persisting gaps in the primary care of depression are due in part to patients’ reluctance to bring depressive symptoms to the attention of their primary care clinician and, when depression is diagnosed, to accept initial treatment for the condition. Both targeted and tailored communication strategies offer promise for fomenting discussion and reducing barriers to appropriate initial treatment of depression. Methods/design The Activating Messages to Enhance Primary Care Practice (AMEP2) Study is a stratified randomized controlled trial comparing two computerized multimedia patient interventions --- one targeted (to patient gender and income level) and one tailored (to level of depressive symptoms, visit agenda, treatment preferences, depression causal attributions, communication self-efficacy and stigma)--- and an attention control. AMEP2 consists of two linked sub-studies, one focusing on patients with significant depressive symptoms (Patient Health Questionnaire-9 [PHQ-9] scores ≥ 5), the other on patients with few or no depressive symptoms (PHQ-9 < 5). The first sub-study examined effectiveness of the interventions; key outcomes included delivery of components of initial depression care (antidepressant prescription or mental health referral). The second sub-study tracked potential hazards (clinical distraction and overtreatment). A telephone interview screening procedure assessed patients for eligibility and oversampled patients with significant depressive symptoms. Sampled, consenting patients used computers to answer survey questions, be randomized, and view assigned interventions just before scheduled primary care office visits. Patient surveys were also collected immediately post-visit and 12 weeks later. Physicians completed brief reporting forms after each patient’s index visit. Additional data were obtained from

  10. A novel polydopamine-based chemiluminescence resonance energy transfer method for microRNA detection coupling duplex-specific nuclease-aided target recycling strategy.

    PubMed

    Wang, Qian; Yin, Bin-Cheng; Ye, Bang-Ce

    2016-06-15

    MicroRNAs (miRNAs), functioning as oncogenes or tumor suppressors, play significant regulatory roles in regulating gene expression and become as biomarkers for disease diagnostics and therapeutics. In this work, we have coupled a polydopamine (PDA) nanosphere-assisted chemiluminescence resonance energy transfer (CRET) platform and a duplex-specific nuclease (DSN)-assisted signal amplification strategy to develop a novel method for specific miRNA detection. With the assistance of hemin, luminol, and H2O2, the horseradish peroxidase (HRP)-mimicking G-rich sequence in the sensing probe produces chemiluminescence, which is quickly quenched by the CRET effect between PDA as energy acceptor and excited luminol as energy donor. The target miRNA triggers DSN to partially degrade the sensing probe in the DNA-miRNA heteroduplex to repeatedly release G-quadruplex formed by G-rich sequence from PDA for the production of chemiluminescence. The method allows quantitative detection of target miRNA in the range of 80 pM-50 nM with a detection limit of 49.6 pM. The method also shows excellent specificity to discriminate single-base differences, and can accurately quantify miRNA in biological samples, with good agreement with the result from a commercial miRNA detection kit. The procedure requires no organic dyes or labels, and is a simple and cost-effective method for miRNA detection for early clinical diagnosis. PMID:26866561

  11. Rapid Discrimination for Traditional Complex Herbal Medicines from Different Parts, Collection Time, and Origins Using High-Performance Liquid Chromatography and Near-Infrared Spectral Fingerprints with Aid of Pattern Recognition Methods

    PubMed Central

    Fu, Haiyan; Fan, Yao; Zhang, Xu; Lan, Hanyue; Yang, Tianming; Shao, Mei; Li, Sihan

    2015-01-01

    As an effective method, the fingerprint technique, which emphasized the whole compositions of samples, has already been used in various fields, especially in identifying and assessing the quality of herbal medicines. High-performance liquid chromatography (HPLC) and near-infrared (NIR), with their unique characteristics of reliability, versatility, precision, and simple measurement, played an important role among all the fingerprint techniques. In this paper, a supervised pattern recognition method based on PLSDA algorithm by HPLC and NIR has been established to identify the information of Hibiscus mutabilis L. and Berberidis radix, two common kinds of herbal medicines. By comparing component analysis (PCA), linear discriminant analysis (LDA), and particularly partial least squares discriminant analysis (PLSDA) with different fingerprint preprocessing of NIR spectra variables, PLSDA model showed perfect functions on the analysis of samples as well as chromatograms. Most important, this pattern recognition method by HPLC and NIR can be used to identify different collection parts, collection time, and different origins or various species belonging to the same genera of herbal medicines which proved to be a promising approach for the identification of complex information of herbal medicines. PMID:26345990

  12. Rapid Discrimination for Traditional Complex Herbal Medicines from Different Parts, Collection Time, and Origins Using High-Performance Liquid Chromatography and Near-Infrared Spectral Fingerprints with Aid of Pattern Recognition Methods.

    PubMed

    Fu, Haiyan; Fan, Yao; Zhang, Xu; Lan, Hanyue; Yang, Tianming; Shao, Mei; Li, Sihan

    2015-01-01

    As an effective method, the fingerprint technique, which emphasized the whole compositions of samples, has already been used in various fields, especially in identifying and assessing the quality of herbal medicines. High-performance liquid chromatography (HPLC) and near-infrared (NIR), with their unique characteristics of reliability, versatility, precision, and simple measurement, played an important role among all the fingerprint techniques. In this paper, a supervised pattern recognition method based on PLSDA algorithm by HPLC and NIR has been established to identify the information of Hibiscus mutabilis L. and Berberidis radix, two common kinds of herbal medicines. By comparing component analysis (PCA), linear discriminant analysis (LDA), and particularly partial least squares discriminant analysis (PLSDA) with different fingerprint preprocessing of NIR spectra variables, PLSDA model showed perfect functions on the analysis of samples as well as chromatograms. Most important, this pattern recognition method by HPLC and NIR can be used to identify different collection parts, collection time, and different origins or various species belonging to the same genera of herbal medicines which proved to be a promising approach for the identification of complex information of herbal medicines. PMID:26345990

  13. 38 CFR 17.190 - Recognition of a State home.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... home. 17.190 Section 17.190 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Aid to States for Care of Veterans in State Homes § 17.190 Recognition of a State home. A State... the Secretary as a State home before Federal aid payments can be made for the care of such...

  14. 38 CFR 17.190 - Recognition of a State home.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... home. 17.190 Section 17.190 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Aid to States for Care of Veterans in State Homes § 17.190 Recognition of a State home. A State... the Secretary as a State home before Federal aid payments can be made for the care of such...

  15. Local ICA for the Most Wanted face recognition

    NASA Astrophysics Data System (ADS)

    Guan, Xin; Szu, Harold H.; Markowitz, Zvi

    2000-04-01

    Facial disguises of FBI Most Wanted criminals are inevitable and anticipated in our design of automatic/aided target recognition (ATR) imaging systems. For example, man's facial hairs may hide his mouth and chin but not necessarily the nose and eyes. Sunglasses will cover the eyes but not the nose, mouth, and chins. This fact motivates us to build sets of the independent component analyses bases separately for each facial region of the entire alleged criminal group. Then, given an alleged criminal face, collective votes are obtained from all facial regions in terms of 'yes, no, abstain' and are tallied for a potential alarm. Moreover, and innocent outside shall fall below the alarm threshold and is allowed to pass the checkpoint. Such a PD versus FAR called ROC curve is obtained.

  16. Recognition of core-derived epitopes from a novel HBV-targeted immunotherapeutic by T-cells from patients infected by different viral genotypes.

    PubMed

    Godon, Ophelie; Evlachev, Alexei; Bourgine, Maryline; Meritet, Jean-François; Martin, Perrine; Inchauspe, Genevieve; Michel, Marie-Louise

    2015-08-26

    Hepatitis B virus (HBV) infects millions of people worldwide and is a leading cause of liver cirrhosis and hepatocellular carcinoma. Current therapies based on nucleos(t)ide analogs or pegylated-interferon-α lead to control of viral replication in most patients but rarely achieve cure. A potential strategy to control chronic hepatitis B is to restore or induce functional anti-HBV T-cell immune responses using HBV-specific immunotherapeutics. However, viral diversity is a challenge to the development of this class of products as HBV genotypes display a sequence diversity of up to 8%. We have developed a novel HBV-targeted immunotherapeutic, TG1050, based on a non-replicative Adenovirus vector encoding a unique and large fusion protein composed of multiple antigenic regions derived from a HBV genotype D sequence. Using peripheral blood mononuclear cells from 23 patients chronically infected by five distinct genotypes (gt A, B, C, D and E) and various sets of peptides encompassing conserved versus divergent regions of HBV core we have measured ability of TG1050 genotype D core-derived peptides to be recognized by T-cells from patients infected by various genotypes. Overall, PBMCs from 78% of genotype B or C- and 100% genotype A or E-infected patients lead to detection of HBV core-specific T-cells recognizing genotype D antigenic domains located both in conserved and variable regions. This proof-of-concept study supports the clinical development of TG1050 in large patient populations independently of infecting genotypes.

  17. A novel target recognition revealed by calmodulin in complex with the basic helix--loop--helix transcription factor SEF2-1/E2-2.

    PubMed

    Larsson, G; Schleucher, J; Onions, J; Hermann, S; Grundström, T; Wijmenga, S S

    2001-01-01

    Calmodulin is the predominant intracellular receptor for Ca(2+) signals, mediating the regulation of numerous cellular processes. It can inhibit the DNA binding of basic helix--loop--helix transcription factors by a direct interaction of a novel type. To structurally characterize this novel calmodulin-target interaction, we decided to study the complex of calmodulin with a dimeric peptide corresponding to the DNA-binding domains of the dimeric basic helix-loop-helix transcription factor SEF2-1 (SEF2-1mp) using NMR. Here, we report that the stoichiometry of the calmodulin:SEF2-1mp complex is one dimeric peptide binding two calmodulin molecules. We also report the 1H, 13C, and 15N resonance assignments and the secondary structure of calmodulin in this for NMR large (approximately 38 kD) complex, as well as the 1H assignments and secondary structure of SEF2-1mp. In addition, we determined the amide proton exchange rates of calmodulin and measured intermolecular calmodulin:SEF2-1mp and calmodulin:calmodulin NOE contacts. The isotope-filtered experiments show a large number of SEF2-1mp to calmodulin NOE contacts indicating that a tight complex is formed, which is confirmed by an intermolecular calmodulin:calmodulin NOE contact. The secondary structure and amide proton exchange data show that the binding does not occur via the classical wraparound binding mode. Instead, the data indicate that calmodulin interacts with SEF2-1mp in a more open conformation, although the hydrophobic surfaces of the N- and C-terminal domains still form the main interaction sites. Interactions involving charged residues are also identified in agreement with the known relatively high sensitivity of the binding to ionic strength. Finally, the peptide does not form an alpha-helix as in the classical wraparound binding mode. PMID:11266605

  18. An Evaluation of Two Signal-Processing Hearing Aids.

    ERIC Educational Resources Information Center

    Dempsey, James J.; Linzalone, Tanya G.

    1991-01-01

    This study, involving 15 older adults with hearing impairments, investigated the relationship between sentence recognition ability and two types of signal processing in hearing aids. Results indicated a significant improvement in sentence recognition when employing an instrument with adaptive compression versus an instrument with an adaptive…

  19. HIV/AIDS Basics

    MedlinePlus

    ... Enter ZIP code or city Follow Act Against AIDS Act Against AIDS @talkHIV Act Against AIDS Get Email Updates on AAA Anonymous Feedback HIV/AIDS Media Infographics Syndicated Content Podcasts Slide Sets HIV/ ...

  20. Food aid: pitfalls and potential.

    PubMed

    Stewart, F

    1986-11-01

    This article poses the question of whether it is possible to use food aid to meet short-run needs while supporting and not undermining the achievement of long-term goals of self-reliance at the household and national levels. Often either some degree of self-reliance is sacrificed or people will suffer malnutrition. Food aid may be used to generate employment for low income families (food-for-work schemes), to reduce food prices during shortages by increasing the supply, and it can be delivered to target groups as a direct entitlement. What happens to food after delivery is important: often it goes to family members not targeted. Other factors (e.g. measles) affect nutritional status. Food aid must often continue for long periods to avoid nutritional regression. The stage in distribution at which food is used is important; e.g. a measles epidemic might affect the consumption but not the supply of food, or poor targeting might benefit families who do not need it. Complementary actions may improve conditions; for example, if food is sold, increasing income improves the situation. A problem with provision of food is depression of local prices, reducing incentives to produce food locally. Most food aid does not increase demand, and in fact if the effect is to change tastes away from local products demand may be reduced. The effect on demand depends on the type of aid scheme, the timing and duration, and the locality of the project. Most objectives are better achieved by the use of cash aid, which promotes rather than weakens local food producers' incentives, reduces transport and storage, redistributes food, does not affect taste, and adds income by contributing to local decentralized transport. Food aid is a good temporary intervention, but cash aid should be used in the long term.

  1. The neuroecology of competitor recognition.

    PubMed

    Grether, Gregory F

    2011-11-01

    Territorial animals can be expected to distinguish among the types of competitors and noncompetitors that they encounter on a regular basis, including prospective mates and rivals of their own species, but they may not correctly classify individuals of other species. Closely related species often have similar phenotypes and this can cause confusion when formerly allopatric populations first come into contact. Errors in recognizing competitors can have important ecological and evolutionary effects. I review what is known about the mechanisms of competitor recognition in animals generally, focusing on cases in which the targets of recognition include other species. Case studies include damselflies, ants, skinks, salamanders, reef fishes, and birds. In general, recognition systems consist of a phenotypic cue (e.g., chemical, color, song), a neural template against which cues are compared, a motor response (e.g., aggression), and sensory integration circuits for context dependency of the response (if any). Little is known about how competitor recognition systems work at the neural level, but inferences about specificity of cues and about sensory integration can be drawn from the responses of territory residents to simulated intruders. Competitor recognition often involves multiple cues in the same, or different, sensory modalities. The same cues and templates are often, but not always, used for intraspecific and interspecific recognition. Experiments have shown that imprinting on local cues is common, which may enable templates to track evolved changes in cues automatically. The dependence of aggression and tolerance on context is important even in the simplest systems. Species in which mechanisms of competitor recognition are best known offer untapped opportunities to examine how competitor-recognition systems evolve (e.g., by comparing allopatric and sympatric populations). Cues that are gene products (peptides, proteins) may provide insights into rates of evolution

  2. AIDS in India: constructive chaos?

    PubMed

    Chatterjee, A

    1991-08-01

    Until recently, the only sustained AIDS activity in India has been alarmist media attention complemented by occasional messages calling for comfort and dignity. Public perception of the AIDS epidemic in India has been effectively shaped by mass media. Press reports have, however, bolstered awareness of the problem among literate elements of urban populations. In the absence of sustained guidance in the campaign against AIDS, responsibility has fallen to voluntary health activists who have become catalysts for community awareness and participation. This voluntary initiative, in effect, seems to be the only immediate avenue for constructive public action, and signals the gradual development of an AIDS network in India. Proceedings from a seminar in Ahmedabad are discussed, and include plans for an information and education program targeting sex workers, health and communication programs for 150 commercial blood donors and their agents, surveillance and awareness programs for safer blood and blood products, and dialogue with the business community and trade unions. Despite the lack of coordination among volunteers and activists, every major city in India now has an AIDS group. A controversial bill on AIDS has ben circulating through government ministries and committees since mid-1989, a national AIDS committee exists with the Secretary of Health as its director, and a 3-year medium-term national plan exists for the reduction of AIDS and HIV infection and morbidity. UNICEF programs target mothers and children for AIDS awareness, and blood testing facilities are expected to be expanded. The article considers the present chaos effectively productive in forcing the Indian population to face up to previously taboo issued of sexuality, sex education, and sexually transmitted disease.

  3. Automatic TLI recognition system, user`s guide

    SciTech Connect

    Lassahn, G.D.

    1997-02-01

    This report describes how to use an automatic target recognition system (version 14). In separate volumes are a general description of the ATR system, Automatic TLI Recognition System, General Description, and a programmer`s manual, Automatic TLI Recognition System, Programmer`s Guide.

  4. Group collaboration in recognition memory.

    PubMed

    Clark, S E; Hori, A; Putnam, A; Martin, T P

    2000-11-01

    Group collaboration was examined in item and associative recognition. The present study distinguishes between group effects versus collaborative processes and defines the latter as interactive information exchange among group members. By that definition, many group effects do not involve collaboration. For example, group performance can exceed individual performance by pooling the increased resources of the group. Specifically, a group advantage can be obtained by deferring to a majority vote or to the group's best member. For both item and associative recognition, a group advantage was obtained that could not be accounted for by resource pooling. Collaborative facilitation was shown reliably in recognizing targets but not for rejecting distractors. PMID:11185784

  5. Recognition Memory: A Review of the Critical Findings and an Integrated Theory for Relating Them

    ERIC Educational Resources Information Center

    Malmberg, Kenneth J.

    2008-01-01

    The development of formal models has aided theoretical progress in recognition memory research. Here, I review the findings that are critical for testing them, including behavioral and brain imaging results of single-item recognition, plurality discrimination, and associative recognition experiments under a variety of testing conditions. I also…

  6. Educating Brazilian workers about AIDS.

    PubMed

    1991-12-01

    This article contains a the script for a slide-tape presentation entitled Working Against AIDS, a presentation developed by the Brazil Family Planning Association (BEMFAM) which is designed to debunk common misconceptions about the disease. This audio-visual, which targets Brazilian workers, can be used during talks, seminars, and meetings. A discussion of the issues involved usually follows the presentation of Working Against AIDS. The presentation contains 30 illustrated slides (these are included in the article). The presentation begins by explaining that much of the information concerning AIDS is prejudicial and misleading. The next few slides point out some of the common misconceptions about AIDS, such as claims denying the existence of the disease, or suggestions that only homosexuals and prostitutes are at risk. The presentation then goes on to explain the ways in which the virus can and cannot be transmitted. Then it discusses how the virus destroys the body's natural defenses and explains the ensuing symptoms. Slides 14 and 15 point out that no cure yet exists for AIDS, making prevention essential. Slides 16-23 explain what actions are considered to be high risk and which ones do not entail risk. Noting that AIDS can be prevented, slide 24 says that the disease should not present an obstacle to spontaneous manifestations of human relations. The next slide explains that condoms should always be used when having sex with someone who could be infected with AIDS. Finally slides 26-30 demonstrate the proper way to use and dispose of a condom.

  7. Manufacturing Aids

    NASA Technical Reports Server (NTRS)

    1989-01-01

    During a research program, MMTC/Textron invented a computer-aided automatic robotic system for spraying hot plasma onto a turbine blade. The need to control the thickness of the plasma deposit led to the development of advanced optical gaging techniques to monitor and control plasma spray build-up on blade surfaces. The techniques led to computerized optical gages for inspecting aircraft, industrial turbine blades, etc. MMTC offers 10 standard commercial robotic gages. The system also generates two dimensional profiles for assessing status and specifying repairs to the electromechanical cathodes used to make the parts. It is capable of accuracies to a ten-thousandth of an inch. An expanded product line is currently marketed. The gages offer multiple improvements in quality control and significant savings.

  8. Smart pattern recognition

    NASA Astrophysics Data System (ADS)

    Alfalou, A.; Brosseau, C.; Alam, M. S.

    2013-03-01

    The purpose of this paper is to test correlation methods for pattern recognition applications. A broad overview of the main correlation architectures is first given. Many correlation data are compared with those obtained from standard pattern recognition methods. We used our simulations to predict improved decisional performance from correlation methods. More specifically, we are focused on the POF filter and composite filter family. We present an optimized composite correlation filter, called asymmetric segmented phase-only filter (ASPOF) for mobile target recognition applications. The main objective is to find a compromise between the number of references to be merged in the correlation filter and the time needed for making a decision. We suggest an all-numerical implementation of a VanderLugt (VLC) type composite filter. The aim of this all-numerical implementation is to take advantage of the benefits of the correlation methods and make the correlator easily reconfigurable for various scenarios. The use of numerical implementation of the optical Fourier transform improves the decisional performance of the correlator. Further, it renders the correlator less sensitive to the saturation phenomenon caused by the increased number of references used for fabricating the composite filter. Different tests are presented making use of the peak-to-correlation energy criterion and ROC curves. These tests confirm the validity ofour technique. Elderly fall detection and underwater mine detection are two applications which are considered for illustrating the benefits of our approach. The present work is motivated by the need for detailed discussions of the choice of the correlation architecture for these specific applications, pre-processing in the input plane and post processing in the output plane techniques for such analysis.

  9. Adolescents, AIDS and HIV. Resources.

    ERIC Educational Resources Information Center

    Resources for Educators, 1990

    1990-01-01

    This compilation of educational resources is designed for communities which have been either overlooked in Acquired Immune Deficiency Syndrome (AIDS) education efforts or disproportionately affected by Human Immunodeficiency Virus (HIV) infection. The materials listed target Blacks, Latinos, Asians and Pacific Islanders, Native Americans, young…

  10. TOPICAL REVIEW: Recognition tunneling

    NASA Astrophysics Data System (ADS)

    Lindsay, Stuart; He, Jin; Sankey, Otto; Hapala, Prokop; Jelinek, Pavel; Zhang, Peiming; Chang, Shuai; Huang, Shuo

    2010-07-01

    Single molecules in a tunnel junction can now be interrogated reliably using chemically functionalized electrodes. Monitoring stochastic bonding fluctuations between a ligand bound to one electrode and its target bound to a second electrode ('tethered molecule-pair' configuration) gives insight into the nature of the intermolecular bonding at a single molecule-pair level, and defines the requirements for reproducible tunneling data. Simulations show that there is an instability in the tunnel gap at large currents, and this results in a multiplicity of contacts with a corresponding spread in the measured currents. At small currents (i.e. large gaps) the gap is stable, and functionalizing a pair of electrodes with recognition reagents (the 'free-analyte' configuration) can generate a distinct tunneling signal when an analyte molecule is trapped in the gap. This opens up a new interface between chemistry and electronics with immediate implications for rapid sequencing of single DNA molecules.

  11. Exploring Biomolecular Recognition by Modeling and Simulation

    NASA Astrophysics Data System (ADS)

    Wade, Rebecca

    2007-12-01

    Biomolecular recognition is complex. The balance between the different molecular properties that contribute to molecular recognition, such as shape, electrostatics, dynamics and entropy, varies from case to case. This, along with the extent of experimental characterization, influences the choice of appropriate computational approaches to study biomolecular interactions. I will present computational studies in which we aim to make concerted use of bioinformatics, biochemical network modeling and molecular simulation techniques to study protein-protein and protein-small molecule interactions and to facilitate computer-aided drug design.

  12. Automatic TLI recognition system beta prototype testing

    SciTech Connect

    Lassahn, G.D.

    1996-06-01

    This report describes the beta prototype automatic target recognition system ATR3, and some performance tests done with this system. This is a fully operational system, with a high computational speed. It is useful for findings any kind of target in digitized image data, and as a general purpose image analysis tool.

  13. Collocation and Pattern Recognition Effects on System Failure Remediation

    NASA Technical Reports Server (NTRS)

    Trujillo, Anna C.; Press, Hayes N.

    2007-01-01

    Previous research found that operators prefer to have status, alerts, and controls located on the same screen. Unfortunately, that research was done with displays that were not designed specifically for collocation. In this experiment, twelve subjects evaluated two displays specifically designed for collocating system information against a baseline that consisted of dial status displays, a separate alert area, and a controls panel. These displays differed in the amount of collocation, pattern matching, and parameter movement compared to display size. During the data runs, subjects kept a randomly moving target centered on a display using a left-handed joystick and they scanned system displays to find a problem in order to correct it using the provided checklist. Results indicate that large parameter movement aided detection and then pattern recognition is needed for diagnosis but the collocated displays centralized all the information subjects needed, which reduced workload. Therefore, the collocated display with large parameter movement may be an acceptable display after familiarization because of the possible pattern recognition developed with training and its use.

  14. Crawling Aid

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The Institute for the Achievement of Human Potential developed a device known as the Vehicle for Initial Crawling (VIC); the acronym is a tribute to the crawler's inventor, Hubert "Vic" Vykukal; is an effective crawling aid. The VIC is used by brain injured children who are unable to crawl due to the problems of weight-bearing and friction, caused by gravity. It is a rounded plywood frame large enough to support the child's torso, leaving arms and legs free to move. On its underside are three aluminum discs through which air is pumped to create an air-bearing surface that has less friction than a film of oil. Upper side contains the connection to the air supply and a pair of straps which restrain the child and cause the device to move with him. VIC is used with the intent to recreate the normal neurological connection between brain and muscles. Over repetitive use of the device the child develops his arm and leg muscles as well as coordination. Children are given alternating therapy, with and without the VIC until eventually the device is no longer needed.

  15. Additive attacks on speaker recognition

    NASA Astrophysics Data System (ADS)

    Farrokh Baroughi, Alireza; Craver, Scott

    2014-02-01

    Speaker recognition is used to identify a speaker's voice from among a group of known speakers. A common method of speaker recognition is a classification based on cepstral coefficients of the speaker's voice, using a Gaussian mixture model (GMM) to model each speaker. In this paper we try to fool a speaker recognition system using additive noise such that an intruder is recognized as a target user. Our attack uses a mixture selected from a target user's GMM model, inverting the cepstral transformation to produce noise samples. In our 5 speaker data base, we achieve an attack success rate of 50% with a noise signal at 10dB SNR, and 95% by increasing noise power to 0dB SNR. The importance of this attack is its simplicity and flexibility: it can be employed in real time with no processing of an attacker's voice, and little computation is needed at the moment of detection, allowing the attack to be performed by a small portable device. For any target user, knowing that user's model or voice sample is sufficient to compute the attack signal, and it is enough that the intruder plays it while he/she is uttering to be classiffed as the victim.

  16. Pattern recognition and cellular immune responses to novel Mycobacterium tuberculosis-antigens in individuals from Belarus

    PubMed Central

    2012-01-01

    Background Tuberculosis (TB) is an enduring health problem worldwide and the emerging threat of multidrug resistant (MDR) TB and extensively drug resistant (XDR) TB is of particular concern. A better understanding of biomarkers associated with TB will aid to guide the development of better targets for TB diagnosis and for the development of improved TB vaccines. Methods Recombinant proteins (n = 7) and peptide pools (n = 14) from M. tuberculosis (M.tb) antigens associated with M.tb pathogenicity, modification of cell lipids or cellular metabolism, were used to compare T cell immune responses defined by IFN-γ production using a whole blood assay (WBA) from i) patients with TB, ii) individuals recovered from TB and iii) individuals exposed to TB without evidence of clinical TB infection from Minsk, Belarus. Results We identified differences in M.tb target peptide recognition between the test groups, i.e. a frequent recognition of antigens associated with lipid metabolism, e.g. cyclopropane fatty acyl phospholipid synthase. The pattern of peptide recognition was broader in blood from healthy individuals and those recovered from TB as compared to individuals suffering from pulmonary TB. Detection of biologically relevant M.tb targets was confirmed by staining for intracellular cytokines (IL-2, TNF-α and IFN-γ) in T cells from non-human primates (NHPs) after BCG vaccination. Conclusions PBMCs from healthy individuals and those recovered from TB recognized a broader spectrum of M.tb antigens as compared to patients with TB. The nature of the pattern recognition of a broad panel of M.tb antigens will devise better strategies to identify improved diagnostics gauging previous exposure to M.tb; it may also guide the development of improved TB-vaccines. PMID:22336002

  17. HIV-AIDS Connection

    MedlinePlus

    ... Marketing Share this: Main Content Area The HIV-AIDS Connection AIDS was first recognized in 1981 and ... is there overwhelming scientific consensus that HIV causes AIDS? Before HIV infection became widespread in the human ...

  18. Heart attack first aid

    MedlinePlus

    First aid - heart attack; First aid - cardiopulmonary arrest; First aid - cardiac arrest ... of patients with unstable angina/non-ST-elevation myocardial infarction (updating the 2007 guideline and replacing the 2011 ...

  19. Splinter, First Aid

    MedlinePlus

    ... and rashes clinical tools newsletter | contact Share | Splinter, First Aid A A A First Aid for Splinter: View ... wet, it makes the area prone to infection. First Aid Guide Self-care measures to remove a splinter ...

  20. Ergogenic aids.

    PubMed

    Coyle, E F

    1984-07-01

    The catabolism of bodily fuels provides the energy for muscular work. Work output can be limited by the size of fuel reserves, the rate of their catabolism, the build-up of by-products, or the neurologic activation of muscle. A substance that favorably affects a step that is normally limiting, and thus increases work output, can be considered an ergogenic aid. The maximal amount of muscular force generated during brief contractions can be acutely increased during hypnosis and with the ingestion of a placebo or psychomotor stimulant. This effect is most obvious in subjects under laboratory conditions and is less evident in athletes who are highly motivated prior to competition. Fatigue is associated with acidosis in the working musculature when attempts are made to maximize work output during a 4 to 15-minute period. Sodium bicarbonate ingestion may act to buffer the acid produced, provided that blood flow to the muscle is adequate. Prolonged intense exercise can be maintained for approximately two hours before carbohydrate stores become depleted. Carbohydrate feedings delay fatigue during prolonged exercise, especially in subjects who display a decline in blood glucose during exercise in the fasting state. Caffeine ingestion prior to an endurance bout has been reported to allow an individual to exercise somewhat more intensely than he or she would otherwise. Its effect may be mediated by augmenting fat metabolism or by altering the perception of effort. Amphetamines may act in a similar manner. Water ingestion during prolonged exercise that results in dehydration and hyperthermia can offset fluid losses and allow an individual to better maintain work output while substantially reducing the risk of heat-related injuries. PMID:6100848

  1. Building Group Recognition.

    ERIC Educational Resources Information Center

    Chartier, George

    1994-01-01

    Discusses the value of name recognition for theater companies. Describes steps toward identity and recognition, analyzing the group, the mission statement, symbolic logic, designing and identity, developing a communications plan, and meaningful activities. (SR)

  2. Speech recognition and understanding

    SciTech Connect

    Vintsyuk, T.K.

    1983-05-01

    This article discusses the automatic processing of speech signals with the aim of finding a sequence of works (speech recognition) or a concept (speech understanding) being transmitted by the speech signal. The goal of the research is to develop an automatic typewriter that will automatically edit and type text under voice control. A dynamic programming method is proposed in which all possible class signals are stored, after which the presented signal is compared to all the stored signals during the recognition phase. Topics considered include element-by-element recognition of words of speech, learning speech recognition, phoneme-by-phoneme speech recognition, the recognition of connected speech, understanding connected speech, and prospects for designing speech recognition and understanding systems. An application of the composition dynamic programming method for the solution of basic problems in the recognition and understanding of speech is presented.

  3. Profiles of Discourse Recognition

    ERIC Educational Resources Information Center

    Singer, Murray

    2013-01-01

    A discourse recognition theory derived from more general memory formulations would be broad in its psychological implications. This study compared discourse recognition with some established profiles of item recognition. Participants read 10 stories either once or twice each. They then rated their confidence in recognizing explicit, paraphrased,…

  4. AIDS in Africa: a political overview.

    PubMed

    Fredland, R A

    1989-01-01

    In examining the spread of AIDS throughout Africa, it is important to recognize the differential factors of geography, economics, politics and other sociodemographic factors. Many factors such as increased prostitution and the presence of socially sanctioned promiscuity in certain communities have helped to accelerate the spread of AIDS. Statistics show that the epidemic is affecting larger numbers and is demanding recognition by political and medical authorities. Between the years 1987 and 1988, the number of AIDS cases in Uganda quadrupled. A hospital in Zaire reported that 1/4 of all deaths recorded in its facility were AIDS related. In certain sections of Central and East Africa, 2-15% of pregnant women are HIV-positive. Poor coping systems and weakened economies have prevented countries from instituting expensive health education programs. Other countries hoping to combat the epidemic might replicate the efforts of Ugandans who have worked diligently to distribute 3 million leaflets of information and open 13 screening centers. It is recognized that the AIDS epidemic will negatively affect Africa's workforce, the combined economies of African nations, and social conditions. Research in the areas of population movements and social practices is crucial to forecast the patterns of the epidemic is needed. Western aid in research and educational activities is also important in Africa's battle against AIDS.

  5. Cross-domain human action recognition.

    PubMed

    Bian, Wei; Tao, Dacheng; Rui, Yong

    2012-04-01

    Conventional human action recognition algorithms cannot work well when the amount of training videos is insufficient. We solve this problem by proposing a transfer topic model (TTM), which utilizes information extracted from videos in the auxiliary domain to assist recognition tasks in the target domain. The TTM is well characterized by two aspects: 1) it uses the bag-of-words model trained from the auxiliary domain to represent videos in the target domain; and 2) it assumes each human action is a mixture of a set of topics and uses the topics learned from the auxiliary domain to regularize the topic estimation in the target domain, wherein the regularization is the summation of Kullback-Leibler divergences between topic pairs of the two domains. The utilization of the auxiliary domain knowledge improves the generalization ability of the learned topic model. Experiments on Weizmann and KTH human action databases suggest the effectiveness of the proposed TTM for cross-domain human action recognition.

  6. Who Benefits from Student Aid? The Economic Incidence of Tax-Based Federal Student Aid

    ERIC Educational Resources Information Center

    Turner, Nicholas

    2012-01-01

    Federal benefit programs, including federal student aid, are designed to aid targeted populations. Behavioral responses to these programs may alter the incidence of their benefits, a possibility that receives less attention in the literature compared to tax incidence. I demonstrate the importance of benefit incidence analysis by showing that the…

  7. Innate Immune Recognition of EBV.

    PubMed

    Lünemann, Anna; Rowe, Martin; Nadal, David

    2015-01-01

    The ability of Epstein-Barr virus (EBV) to establish latency despite specific immune responses and to successfully persist lifelong in the human host shows that EBV has developed powerful strategies and mechanisms to exploit, evade, abolish, or downsize otherwise effective immune responses to ensure its own survival. This chapter focuses on current knowledge on innate immune responses against EBV and its evasion strategies for own benefit and summarizes the questions that remain to be tackled. Innate immune reactions against EBV originate both from the main target cells of EBV and from nontarget cells, which are elements of the innate immune system. Thus, we structured our review accordingly but with a particular focus on the innate recognition of EBV in its two stages in its life cycle, latent state and lytic replication. Specifically, we discuss (I) innate sensing and resulting innate immune responses against EBV by its main target cells, focusing on (i) EBV transmission between epithelial cells and B cells and their life cycle stages; and (ii) elements of innate immunity in EBV's target cells. Further, we debate (II) the innate recognition and resulting innate immune responses against EBV by cells other than the main target cells, focusing on (iii) myeloid cells: dendritic cells, monocytes, macrophages, and neutrophil granulocytes; and (iv) natural killer cells. Finally, we address (III) how EBV counteracts or exploits innate immunity in its latent and lytic life cycle stages, concentrating on (v) TLRs; (vi) EBERs; and (vii) microRNAs. PMID:26428378

  8. The Master Hearing Aid

    PubMed Central

    Curran, James R.

    2013-01-01

    As early as the 1930s the term Master Hearing Aid (MHA) described a device used in the fitting of hearing aids. In their original form, the MHA was a desktop system that allowed for simulated or actual adjustment of hearing aid components that resulted in a changed hearing aid response. Over the years the MHA saw many embodiments and contributed to a number of rationales for the fitting of hearing aids. During these same years, the MHA was viewed by many as an inappropriate means of demonstrating hearing aids; the audio quality of the desktop systems was often superior to the hearing aids themselves. These opinions and the evolution of the MHA have molded the modern perception of hearing aids and the techniques used in the fitting of hearing aids. This article reports on a history of the MHA and its influence on the fitting of hearing aids. PMID:23686682

  9. Immune recognition of citrullinated epitopes.

    PubMed

    Nguyen, Hai; James, Eddie A

    2016-10-01

    Conversion of arginine into citrulline is a post-translational modification that is observed in normal physiological processes. However, abnormal citrullination can provoke autoimmunity by generating altered self-epitopes that are specifically targeted by autoantibodies and T cells. In this review we discuss the recognition of citrullinated antigens in human autoimmune diseases and the role that this modification plays in increasing antigenic diversity and circumventing tolerance mechanisms. Early published work demonstrated that citrullinated proteins are specifically targeted by autoantibodies in rheumatoid arthritis and that citrullinated peptides are more readily presented to T cells by arthritis-susceptible HLA class II 'shared epitope' proteins. Emerging data support the relevance of citrullinated epitopes in other autoimmune diseases, including type 1 diabetes and multiple sclerosis, whose susceptible HLA haplotypes also preferentially present citrullinated peptides. In these settings, autoimmune patients have been shown to have elevated responses to citrullinated epitopes derived from tissue-specific antigens. Contrasting evidence implicates autophagy or perforin and complement-mediated membrane attack as inducers of ectopic citrullination. In either case, the peptidyl deiminases responsible for citrullination are activated in response to inflammation or insult, providing a mechanistic link between this post-translational modification and interactions with the environment and infection. As such, it is likely that immune recognition of citrullinated epitopes also plays a role in pathogen clearance. Indeed, our recent data suggest that responses to citrullinated peptides facilitate recognition of novel influenza strains. Therefore, increased understanding of responses to citrullinated epitopes may provide important insights about the initiation of autoimmunity and recognition of heterologous viruses. PMID:27531825

  10. [Gender, human rights and socioeconomic impact of AIDS in Brazil].

    PubMed

    de Oliveira, Rosa Maria Rodrigues

    2006-04-01

    The paper critically analyzes, from the gender standpoint, official results presented in the Brazilian government report to the Joint United Nations Programme on HIV/AIDS (UNAIDS). Specifically, the fulfillment of 2003 targets set forth in the United Nations Declaration of Commitment on HIV/AIDS, under the category of Human Rights and Reduction of the Economic and Social Impact of AIDS, are evaluated. Key concepts are highlighted, including indicators and strategies that may help civilian society better monitor these targets until 2010.

  11. Recognition of movement object collision

    NASA Astrophysics Data System (ADS)

    Chang, Hsiao Tsu; Sun, Geng-tian; Zhang, Yan

    1991-03-01

    The paper explores the collision recognition of two objects in both crisscross and revolution motions A mathematical model has been established based on the continuation theory. The objects of any shape may be regarded as being built of many 3siniplexes or their convex hulls. Therefore the collision problem of two object in motion can be reduced to the collision of two corresponding 3siinplexes on two respective objects accordingly. Thus an optimized algorithm is developed for collision avoidance which is suitable for computer control and eliminating the need for vision aid. With this algorithm computation time has been reduced significantly. This algorithm is applicable to the path planning of mobile robots And also is applicable to collision avoidance of the anthropomorphic arms grasping two complicated shaped objects. The algorithm is realized using LISP language on a VAX8350 minicomputer.

  12. Methodology for target discrimination.

    PubMed

    McNolty, F; Clow, R

    1980-03-15

    The objective is to distinguish the true target from point-target imitators and from extended-target clutter in the exoatmospheric regime. Matched filters are carefully studied from the viewpoint of SNR enhancement and pulse recognition. The matched filter structure takes into account photon noise, modulation noise, generation-recombination (GR) noise, contact noise, and various thermal noise sources. A multicolor radiant-intensity structure for target discrimination is developed by analyzing the uncertainties in such target irradiance parameters as range, temperature, projected area, and emissivity. Bias terms, variances, and other statistical descriptors are derived. Certain statistical discrimination techniques are discussed that exploit the radiant-intensity format. Helstrom's method for processing radar signals is adapted to a fourchannel pulse-recognition system for which degradation due to arrival time delays and mismatched filters is discussed.

  13. Window Size Impact in Human Activity Recognition

    PubMed Central

    Banos, Oresti; Galvez, Juan-Manuel; Damas, Miguel; Pomares, Hector; Rojas, Ignacio

    2014-01-01

    Signal segmentation is a crucial stage in the activity recognition process; however, this has been rarely and vaguely characterized so far. Windowing approaches are normally used for segmentation, but no clear consensus exists on which window size should be preferably employed. In fact, most designs normally rely on figures used in previous works, but with no strict studies that support them. Intuitively, decreasing the window size allows for a faster activity detection, as well as reduced resources and energy needs. On the contrary, large data windows are normally considered for the recognition of complex activities. In this work, we present an extensive study to fairly characterize the windowing procedure, to determine its impact within the activity recognition process and to help clarify some of the habitual assumptions made during the recognition system design. To that end, some of the most widely used activity recognition procedures are evaluated for a wide range of window sizes and activities. From the evaluation, the interval 1–2 s proves to provide the best trade-off between recognition speed and accuracy. The study, specifically intended for on-body activity recognition systems, further provides designers with a set of guidelines devised to facilitate the system definition and configuration according to the particular application requirements and target activities. PMID:24721766

  14. Window size impact in human activity recognition.

    PubMed

    Banos, Oresti; Galvez, Juan-Manuel; Damas, Miguel; Pomares, Hector; Rojas, Ignacio

    2014-01-01

    Signal segmentation is a crucial stage in the activity recognition process; however, this has been rarely and vaguely characterized so far. Windowing approaches are normally used for segmentation, but no clear consensus exists on which window size should be preferably employed. In fact, most designs normally rely on figures used in previous works, but with no strict studies that support them. Intuitively, decreasing the window size allows for a faster activity detection, as well as reduced resources and energy needs. On the contrary, large data windows are normally considered for the recognition of complex activities. In this work, we present an extensive study to fairly characterize the windowing procedure, to determine its impact within the activity recognition process and to help clarify some of the habitual assumptions made during the recognition system design. To that end, some of the most widely used activity recognition procedures are evaluated for a wide range of window sizes and activities. From the evaluation, the interval 1-2 s proves to provide the best trade-off between recognition speed and accuracy. The study, specifically intended for on-body activity recognition systems, further provides designers with a set of guidelines devised to facilitate the system definition and configuration according to the particular application requirements and target activities. PMID:24721766

  15. Statistical-techniques-based computer-aided diagnosis (CAD) using texture feature analysis: application in computed tomography (CT) imaging to fatty liver disease

    NASA Astrophysics Data System (ADS)

    Chung, Woon-Kwan; Park, Hyong-Hu; Im, In-Chul; Lee, Jae-Seung; Goo, Eun-Hoe; Dong, Kyung-Rae

    2012-09-01

    This paper proposes a computer-aided diagnosis (CAD) system based on texture feature analysis and statistical wavelet transformation technology to diagnose fatty liver disease with computed tomography (CT) imaging. In the target image, a wavelet transformation was performed for each lesion area to set the region of analysis (ROA, window size: 50 × 50 pixels) and define the texture feature of a pixel. Based on the extracted texture feature values, six parameters (average gray level, average contrast, relative smoothness, skewness, uniformity, and entropy) were determined to calculate the recognition rate for a fatty liver. In addition, a multivariate analysis of the variance (MANOVA) method was used to perform a discriminant analysis to verify the significance of the extracted texture feature values and the recognition rate for a fatty liver. According to the results, each texture feature value was significant for a comparison of the recognition rate for a fatty liver ( p < 0.05). Furthermore, the F-value, which was used as a scale for the difference in recognition rates, was highest in the average gray level, relatively high in the skewness and the entropy, and relatively low in the uniformity, the relative smoothness and the average contrast. The recognition rate for a fatty liver had the same scale as that for the F-value, showing 100% (average gray level) at the maximum and 80% (average contrast) at the minimum. Therefore, the recognition rate is believed to be a useful clinical value for the automatic detection and computer-aided diagnosis (CAD) using the texture feature value. Nevertheless, further study on various diseases and singular diseases will be needed in the future.

  16. Automatic TLI recognition system, programmer`s guide

    SciTech Connect

    Lassahn, G.D.

    1997-02-01

    This report describes the software of an automatic target recognition system (version 14), from a programmer`s point of view. The intent is to provide information that will help people who wish to modify the software. In separate volumes are a general description of the ATR system, Automatic TLI Recognition System, General Description, and a user`s manual, Automatic TLI Recognition System, User`s Guide. 2 refs.

  17. Recognition without awareness: Encoding and retrieval factors.

    PubMed

    Craik, Fergus I M; Rose, Nathan S; Gopie, Nigel

    2015-09-01

    The article reports 4 experiments that explore the notion of recognition without awareness using words as the material. Previous work by Voss and associates has shown that complex visual patterns were correctly selected as targets in a 2-alternative forced-choice (2-AFC) recognition test although participants reported that they were guessing. The present experiments sought to extend this earlier work by having participants study words in different ways and then attempt to recognize the words later in a series of 4-alternative forced-choice (4-AFC) tests, some of which contained no target word. The data of interest are cases in which a target was present and participants stated that they were guessing, yet chose the correct item. This value was greater than p = .25 in all conditions of the 4 experiments, demonstrating the phenomenon of recognition without awareness. Whereas Voss and colleagues attributed their findings with kaleidoscope patterns to enhanced processing fluency of perceptual attributes, the main factor associated with different levels of recognition without awareness in the present studies was a variable criterion for the subjective state accompanying selection of the "guess" option, depending on the overall difficulty of the recognition test. We conclude by discussing some implications of the results for the distinction between implicit and explicit memory. PMID:26010824

  18. Automatic TLI recognition system, general description

    SciTech Connect

    Lassahn, G.D.

    1997-02-01

    This report is a general description of an automatic target recognition system developed at the Idaho National Engineering Laboratory for the Department of Energy. A user`s manual is a separate volume, Automatic TLI Recognition System, User`s Guide, and a programmer`s manual is Automatic TLI Recognition System, Programmer`s Guide. This system was designed as an automatic target recognition system for fast screening of large amounts of multi-sensor image data, based on low-cost parallel processors. This system naturally incorporates image data fusion, and it gives uncertainty estimates. It is relatively low cost, compact, and transportable. The software is easily enhanced to expand the system`s capabilities, and the hardware is easily expandable to increase the system`s speed. In addition to its primary function as a trainable target recognition system, this is also a versatile, general-purpose tool for image manipulation and analysis, which can be either keyboard-driven or script-driven. This report includes descriptions of three variants of the computer hardware, a description of the mathematical basis if the training process, and a description with examples of the system capabilities.

  19. Multimodal eye recognition

    NASA Astrophysics Data System (ADS)

    Zhou, Zhi; Du, Yingzi; Thomas, N. L.; Delp, Edward J., III

    2010-04-01

    Multimodal biometrics use more than one means of biometric identification to achieve higher recognition accuracy, since sometimes a unimodal biometric is not good enough used to do identification and classification. In this paper, we proposed a multimodal eye recognition system, which can obtain both iris and sclera patterns from one color eye image. Gabor filter and 1-D Log-Gabor filter algorithms have been applied as the iris recognition algorithms. In sclera recognition, we introduced automatic sclera segmentation, sclera pattern enhancement, sclera pattern template generation, and sclera pattern matching. We applied kernelbased matching score fusion to improve the performance of the eye recognition system. The experimental results show that the proposed eye recognition method can achieve better performance compared to unimodal biometric identification, and the accuracy of our proposed kernel-based matching score fusion method is higher than two classic linear matching score fusion methods: Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA).

  20. Kin Recognition in Bacteria.

    PubMed

    Wall, Daniel

    2016-09-01

    The ability of bacteria to recognize kin provides a means to form social groups. In turn these groups can lead to cooperative behaviors that surpass the ability of the individual. Kin recognition involves specific biochemical interactions between a receptor(s) and an identification molecule(s). Recognition specificity, ensuring that nonkin are excluded and kin are included, is critical and depends on the number of loci and polymorphisms involved. After recognition and biochemical perception, the common ensuing cooperative behaviors include biofilm formation, quorum responses, development, and swarming motility. Although kin recognition is a fundamental mechanism through which cells might interact, microbiologists are only beginning to explore the topic. This review considers both molecular and theoretical aspects of bacterial kin recognition. Consideration is also given to bacterial diversity, genetic relatedness, kin selection theory, and mechanisms of recognition. PMID:27359217

  1. Answering the AIDS denialists: is AIDS real?

    PubMed

    Mirken, B

    2000-12-01

    This article looks at theories that say AIDS does not exist, or is not a new disease but only a collection of old ones--and explains some of the history behind earlier changes in the official definition of AIDS in the U.S., changes which caused some public confusion. PMID:12171004

  2. Improving protein fold recognition by random forest

    PubMed Central

    2014-01-01

    Background Recognizing the correct structural fold among known template protein structures for a target protein (i.e. fold recognition) is essential for template-based protein structure modeling. Since the fold recognition problem can be defined as a binary classification problem of predicting whether or not the unknown fold of a target protein is similar to an already known template protein structure in a library, machine learning methods have been effectively applied to tackle this problem. In our work, we developed RF-Fold that uses random forest - one of the most powerful and scalable machine learning classification methods - to recognize protein folds. Results RF-Fold consists of hundreds of decision trees that can be trained efficiently on very large datasets to make accurate predictions on a highly imbalanced dataset. We evaluated RF-Fold on the standard Lindahl's benchmark dataset comprised of 976 × 975 target-template protein pairs through cross-validation. Compared with 17 different fold recognition methods, the performance of RF-Fold is generally comparable to the best performance in fold recognition of different difficulty ranging from the easiest family level, the medium-hard superfamily level, and to the hardest fold level. Based on the top-one template protein ranked by RF-Fold, the correct recognition rate is 84.5%, 63.4%, and 40.8% at family, superfamily, and fold levels, respectively. Based on the top-five template protein folds ranked by RF-Fold, the correct recognition rate increases to 91.5%, 79.3% and 58.3% at family, superfamily, and fold levels. Conclusions The good performance achieved by the RF-Fold demonstrates the random forest's effectiveness for protein fold recognition. PMID:25350499

  3. Diagnostic odor recognition

    PubMed

    Rosenblatt; Phan; Desandre; Lobon; Hsu

    2000-10-01

    Many diseases, toxic ingestions, and intoxications have characteristic odors. These odors may provide diagnostic clues that affect rapid treatment long before laboratory confirmation or clinical deterioration. Odor recognition skills, similar to auscultation and palpation skills, require teaching and practical exposure. Dr. Goldfrank and colleagues recognized the importance of teaching odor recognition to emergency service providers. They proposed the "sniffing bar" method for odor recognition training. OBJECTIVES: (1) To identify the recognition rates of medically important odors among emergency care providers. (2) To investigate the effectiveness of teaching odor recognition. Hypothesis: The recognition rates of medically important odors will increase after teaching exposure. METHODS: The study exposed emergency care providers to 11 tubes of odors. Identifications of each substance were recorded. After corrective feedback, subjects were re-tested on their ability to identify the odors. Analysis of odor recognition improvement after teaching was done via chi-square test. RESULTS: Improvement in identification after teaching was seen in all odors. However, the improvement was significant only in the lesscommon substances because their initial recognition was especially low. Significant changes may improve with a larger sample size. Subjects often confuse the odors of alcohol with acetone, and wintergreen with camphor. CONCLUSIONS: The recognition rates are higher for the more-common odors, and lower for the less-common odors. Teaching exposures to the less well-known odors are effective and can significantly improve the recognition rate of these substances. Because odor recognition may affect rapid diagnosis and treatment of certain medical emergencies such as toxic ingestion, future studies should investigate the correlation between odor recognition and the ability to identify corresponding medical emergencies.

  4. Focus on the Forms: Recognition Practice in Chinese Vocabulary Learning

    ERIC Educational Resources Information Center

    Harrington, Michael; Jiang, Wenying

    2013-01-01

    This study examines the effect of recognition-based retrieval practice on vocabulary learning in a university Chinese class. Students (N=26) were given practice retrieving new vocabulary (single or two-character words) in a series of simple form recognition tests administered over four weeks. The test sets consisted of target vocabulary that…

  5. Speech-in-Speech Recognition: A Training Study

    ERIC Educational Resources Information Center

    Van Engen, Kristin J.

    2012-01-01

    This study aims to identify aspects of speech-in-noise recognition that are susceptible to training, focusing on whether listeners can learn to adapt to target talkers ("tune in") and learn to better cope with various maskers ("tune out") after short-term training. Listeners received training on English sentence recognition in speech-shaped noise…

  6. HIV/AIDS in African Americans. National Minority AIDS Council.

    PubMed

    1998-06-01

    The National Minority AIDS Council (NMAC) answered the call of the Congressional Black Caucus by asking President Clinton to declare a state of emergency on HIV and AIDS among African-Americans. The Centers for Disease Control and Prevention (CDC) estimates that of the seven Americans infected with HIV every hour, three are African-Americans. NMAC is calling on Federal, State, and local government leaders to implement widespread public information and education campaigns that target African-Americans, and that address voluntary HIV testing, dispel the shame and stigma associated with HIV/AIDS, discuss the needs of gay African-American men, address the accessibility of appropriate resources for HIV treatment, coordinate the expansion of drug prevention and treatment programs, implement a national needle exchange policy, and allocate funds for researching HIV treatment in minority populations. Dr. Beny Primm, vice-chair of NMAC, states that efforts to fight HIV/AIDS must be integrated with other obstacles affecting the African-American community.

  7. How HIV Causes AIDS

    MedlinePlus

    ... Share this: Main Content Area How HIV Causes AIDS HIV destroys CD4 positive (CD4+) T cells, which ... and disease, ultimately resulting in the development of AIDS. Most people who are infected with HIV can ...

  8. AIDS Myths and Misunderstandings

    MedlinePlus

    ... 21, 2014 Select a Language: Fact Sheet 158 AIDS Myths and Misunderstandings WHY ARE THERE SO MANY ... support this belief. Myth: Current medications can cure AIDS. It’s no big deal if you get infected. ...

  9. HIV/AIDS

    MedlinePlus

    ... at risk for serious infections and certain cancers. AIDS stands for acquired immunodeficiency syndrome. It is the final stage of infection with HIV. Not everyone with HIV develops AIDS. HIV most often spreads through unprotected sex with ...

  10. Students with AIDS.

    ERIC Educational Resources Information Center

    Broadwell, Cathy Allen; Strope, John L., Jr.

    1989-01-01

    Addresses the law as it pertains to Acquired Immune Deficiency Syndrome (AIDS) in public elementary and secondary schools. Section 504 of the Rehabilitation Act of 1973 has been used successfully in the majority of the AIDS cases discussed. (MLF)

  11. Unconsciousness - first aid

    MedlinePlus

    Loss of consciousness - first aid; Coma - first aid; Mental status change; Altered mental status ... person is unconscious and: Does not return to consciousness quickly (within a minute) Has fallen down or ...

  12. Frostbite, First Aid

    MedlinePlus

    ... and rashes clinical tools newsletter | contact Share | Frostbite, First Aid A A A Severe frostbite can result in ... became frozen). Frostbite is often associated with hypothermia. First Aid Guide In the case of mild frostbite, the ...

  13. Heat Exhaustion, First Aid

    MedlinePlus

    ... rashes clinical tools newsletter | contact Share | Heat Exhaustion, First Aid A A A Heat exhaustion signs and symptoms ... specific to the other stages of heat illness. First Aid Guide Use a combination of the following measures ...

  14. Heat Cramps, First Aid

    MedlinePlus

    ... rashes clinical tools newsletter | contact Share | Heat Cramps, First Aid A A A Heat cramp signs and symptoms ... if later stages of heat illness are suspected. First Aid Guide Use a combination of the following measures, ...

  15. Heatstroke, First Aid

    MedlinePlus

    ... and rashes clinical tools newsletter | contact Share | Heatstroke, First Aid A A A Heatstroke signs and symptoms can ... specific to the earlier stages of heat illness. First Aid Guide When heatstroke is suspected, seek emergency medical ...

  16. Bruises, First Aid

    MedlinePlus

    ... and rashes clinical tools newsletter | contact Share | Bruises, First Aid A A A Bruises lighten and change color ... Bruises can be a sign of internal bleeding. First Aid Guide If there is external bleeding in addition ...

  17. Tick Bites, First Aid

    MedlinePlus

    ... rashes clinical tools newsletter | contact Share | Tick Bites, First Aid A A A It is important to inspect ... temporary paralysis in their host (called tick paralysis). First Aid Guide To remove an embedded tick: Wash your ...

  18. First Aid: Influenza (Flu)

    MedlinePlus

    ... to Know About Zika & Pregnancy First Aid: The Flu KidsHealth > For Parents > First Aid: The Flu Print ... tiredness What to Do If Your Child Has Flu Symptoms: Call your doctor. Encourage rest. Keep your ...

  19. Hearing-aid tester

    NASA Technical Reports Server (NTRS)

    Kessinger, R.; Polhemus, J. T.; Waring, J. G.

    1977-01-01

    Hearing aids are automatically checked by circuit that applies half-second test signal every thirty minutes. If hearing-aid output is distorted, too small, or if battery is too low, a warning lamp is activated. Test circuit is incorporated directly into hearing-aid package.

  20. HIV and AIDS

    MedlinePlus

    ... I Help a Friend Who Cuts? HIV and AIDS KidsHealth > For Teens > HIV and AIDS Print A A A Text Size What's in ... in human history. HIV causes a condition called acquired immunodeficiency syndrome — better known as AIDS . HIV destroys a type ...

  1. Designing State Aid Formulas

    ERIC Educational Resources Information Center

    Zhao, Bo; Bradbury, Katharine

    2009-01-01

    This paper designs a new equalization-aid formula based on fiscal gaps of local communities. When states are in transition to a new local aid formula, the issue of whether and how to hold existing aid harmless poses a challenge. The authors show that some previous studies and the formulas derived from them give differential weights to existing and…

  2. AIDS Education Curriculum Guide.

    ERIC Educational Resources Information Center

    Horry County Board of Education, Conway, SC.

    This curriculum guide was developed, based on sound principles of human growth and development, to present the most recently available information on AIDS (Acquired Immune Deficiency Syndrome). The curriculum presents information on the known facts about AIDS and the AIDS virus infection. It also addresses the potential for adolescents and adults…

  3. First Aid: Rashes

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy First Aid: Rashes KidsHealth > For Parents > First Aid: Rashes Print A A A Text Size Rashes ... For Kids For Parents MORE ON THIS TOPIC First Aid: Skin Infections Poison Ivy Erythema Multiforme Hives (Urticaria) ...

  4. First Aid: Burns

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy First Aid: Burns KidsHealth > For Parents > First Aid: Burns Print A A A Text Size Scald ... THIS TOPIC Kitchen: Household Safety Checklist Fireworks Safety First Aid: Sunburn Firesetting Fire Safety Burns Household Safety: Preventing ...

  5. First Aid: Croup

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy First Aid: Croup KidsHealth > For Parents > First Aid: Croup Print A A A Text Size Croup ... For Kids For Parents MORE ON THIS TOPIC First Aid: Coughing X-Ray Exam: Neck Why Is Hand ...

  6. First Aid: Falls

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy First Aid: Falls KidsHealth > For Parents > First Aid: Falls Print A A A Text Size en ... Floors, Doors & Windows, Furniture, Stairways: Household Safety Checklist First Aid: Broken Bones Head Injuries Preventing Children's Sports Injuries ...

  7. First Aid: Choking

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy First Aid: Choking KidsHealth > For Parents > First Aid: Choking Print A A A Text Size Choking ... usually are taught as part of any basic first-aid course. Reviewed by: Steven Dowshen, MD Date reviewed: ...

  8. First Aid: Dehydration

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy First Aid: Dehydration KidsHealth > For Parents > First Aid: Dehydration Print A A A Text Size Dehydration ... MORE ON THIS TOPIC Summer Safety Heat Illness First Aid: Heat Illness Sun Safety Dehydration Diarrhea Vomiting Word! ...

  9. First Aid: Animal Bites

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy First Aid: Animal Bites KidsHealth > For Parents > First Aid: Animal Bites Print A A A Text Size ... For Kids For Parents MORE ON THIS TOPIC First Aid & Safety Center Infections That Pets Carry Dealing With ...

  10. A Teaching Aids Exhibition.

    ERIC Educational Resources Information Center

    Mahanja, Salah

    1985-01-01

    Describes an exhibition for the benefit of teachers of English in Arab Primary Schools, which was prepared by third-year students at the Teachers College for Arab Teachers. The exhibition included games, songs, audiovisual aids, crossword puzzles, vocabulary, spelling booklets, preposition aids, and worksheet and lesson planning aids. (SED)

  11. Space Derived Health Aids (AID, Heart Monitor)

    NASA Technical Reports Server (NTRS)

    1981-01-01

    CPI's spinoff from miniaturized pace circuitry is the new heart-assist device, the AID implantable automatic pulse generator. AID pulse generator monitors the heart continuously, recognizes onset of fibrillation, then administers a corrective electrical shock. A mini- computer, a power source, and two electrodes which sense heart activity are included in the unit. An associated system was also developed. It includes an external recorder to be worn by AID patients and a physician's console to display the data stored by the recorder. System provides a record of fibrillation occurrences and the ensuing defibrillation.

  12. Moreland Recognition Program.

    ERIC Educational Resources Information Center

    Moreland Elementary School District, San Jose, CA.

    THE FOLLOWING IS THE FULL TEXT OF THIS DOCUMENT: Recognition for special effort and achievement has been noted as a component of effective schools. Schools in the Moreland School District have effectively improved standards of discipline and achievement by providing forty-six different ways for children to receive positive recognition. Good…

  13. Infant Visual Recognition Memory

    ERIC Educational Resources Information Center

    Rose, Susan A.; Feldman, Judith F.; Jankowski, Jeffery J.

    2004-01-01

    Visual recognition memory is a robust form of memory that is evident from early infancy, shows pronounced developmental change, and is influenced by many of the same factors that affect adult memory; it is surprisingly resistant to decay and interference. Infant visual recognition memory shows (a) modest reliability, (b) good discriminant…

  14. Aircraft recognition and tracking device

    NASA Astrophysics Data System (ADS)

    Filis, Dimitrios P.; Renios, Christos I.

    2011-11-01

    The technology of aircraft recognition and tracking has various applications in all areas of air navigation, be they civil or military, spanning from air traffic control and regulation at civilian airports to anti-aircraft weapon handling and guidance for military purposes.1, 18 The system presented in this thesis is an alternative implementation of identifying and tracking flying objects, which benefits from the optical spectrum by using an optical camera built into a servo motor (pan-tilt unit). More specifically, through the purpose-developed software, when a target (aircraft) enters the field of view of the camera18, it is both detected and identified.5, 22 Then the servo motor, being provided with data on target position and velocity, tracks the aircraft while it is in constant communication with the camera (Fig. 1). All the features are so designed as to operate under real time conditions.

  15. Regulation of Aicda expression and AID activity.

    PubMed

    Zan, Hong; Casali, Paolo

    2013-03-01

    Activation-induced cytidine deaminase (AID) is expressed in a B cell differentiation stage-specific fashion and is essential for immunoglobulin (Ig) gene class switch DNA recombination (CSR) and somatic hypermutation (SHM). CSR and SHM play a central role in the maturation of antibody and autoantibody responses. AID displays a mutagenic activity by catalyzing targeted deamination of deoxycytidine (dC) residues in DNA resulting in dU:dG mismatches, which are processed into point-mutations in SHM or double-strand breaks (DSBs) in CSR. Although AID specifically targets the Ig gene loci (IgH, Igκ and Igλ), it can also home into a wide array of non-Ig genes in B-and non-B-cell backgrounds. Aberrant expression of AID is associated with multiple diseases such as allergy, inflammation, autoimmunity and cancer. In autoimmune systemic lupus erythematosus, dysregulated AID expression underpins increased CSR, SHM and autoantibody production. As a potent mutator, AID is under stringent transcriptional, post-transcriptional and post-translational regulation. AID is also regulated in its targeting and enzymatic function. In resting naïve or memory B cells, AID transcripts and protein are undetectable. These, however, are readily and significantly up-regulated in B cells induced to undergo CSR and/or SHM. Transcription factors, such as HoxC4 and NF-κB, which are up-regulated in a B cell lineage-and/or differentiation stage-specific manner, regulate the induction of AID. HoxC4 induces AID expression by directly binding to the AID gene promoter through an evolutionarily conserved 5'-ATTT-3' motif. HoxC4 is induced by the same stimuli that induce AID and CSR. It is further up-regulated by estrogen through three estrogen responsive elements in its promoter region. The targeting of AID to switch (S) regions is mediated by 14-3-3 adaptor proteins, which specifically bind to 5'-AGCT-3' repeats that are exist at high frequency in S region cores. Like HoxC4, 14-3-3 adaptors are induced

  16. AIDS education -- theory and practice. AIDS education: getting the right message across.

    PubMed

    1990-01-01

    In the absence of a drug or vaccine to curtail the acquired immunodeficiency syndrome (AIDS) epidemic, health education offers the most productive approach. The majority of National AIDS Committees have established AIDS education programs aimed at reducing the high-risk behaviors associated with AIDS. The content of an AIDS educational program varies according to the educational level and cultural norms of the target audience, but is crucial to determining whether misconceptions and prejudices about the disease will be reinforced or dispelled. It is suggested that all AIDS-related materials should be examined in relation to the following factors: accuracy (correct statistics and factually true statements); current (the presentation of present trends and developments); appropriate to objectives (suitable for the purpose); appropriate to the level of the target audience (in terms of not only literacy level, but also emotional maturity and special sensitivities); adequate (sufficient information as to be useful); and objective and unbiased. Each subject covered in AIDS prevention materials--the natural history of the epidemic, the nature of infection with AIDS, signs and symptoms, modes of transmission, and preventive strategies--should be analyzed in relation to the above factors.

  17. Hearing Aid Assembly

    NASA Technical Reports Server (NTRS)

    Grugel, Richard N. (Inventor)

    2002-01-01

    Progress in hearing aids has come a long way. Yet despite such progress hearing aids are not the perfect answer to many hearing problems. Some adult ears cannot accommodate tightly fitting hearing aids. Mouth movements such as chewing, talking, and athletic or other active endeavors also lead to loosely fitting ear molds. It is well accepted that loosely fitting hearing aids are the cause of feedback noise. Since feedback noise is the most common complaint of hearing aid wearers it has been the subject of various patents. Herein a hearing aid assembly is provided eliminating feedback noise. The assembly includes the combination of a hearing aid with a headset developed to constrict feedback noise.

  18. HIV, AIDS, and the Future

    MedlinePlus

    ... Navigation Bar Home Current Issue Past Issues HIV / AIDS HIV, AIDS, and the Future Past Issues / Summer 2009 Table ... and your loved ones from HIV/AIDS. The AIDS Memorial Quilt In 1987, a total of 1, ...

  19. Anti-class II antibodies in AIDS patients and AIDS-risk groups.

    PubMed Central

    de la Barrera, S; Fainboim, L; Lugo, S; Picchio, G R; Muchinik, G R; de Bracco, M M

    1987-01-01

    The specificity of anti-lymphocyte antibodies was evaluated in AIDS patients and in individuals at risk of AIDS [R-AIDS: male homosexuals (Ho) and haemophiliacs (He)]. Antibodies capable of inducing antibody-dependent cell-mediated cytotoxicity (ADCC) against non-T cells and lymphoblastoid cell lines (P3HR-1K and Raji) were detected in AIDS patients and in R-AIDS with positive or negative human immune deficiency virus (HIV) serology. Anti-class II antigen specificity was revealed by experiments in which class II antigens on target cells were blocked with monoclonal anti-class II antibody (DA6,231) and the cytotoxic reaction induced by patient's sera was abolished. In contrast, ADCC was not impaired by preincubating the target cells with anti-class I monoclonal antibody (W6/32). Prevalence of antibodies to non-T cells was confirmed by standard C-mediated microlymphocytotoxicity. However, with this technique anti-T lymphocyte cytotoxicity was also observed in three AIDS patients with haemophilia. R-AIDS peripheral blood mononuclear cells (PBMC) were also cytotoxic against autologous non-T cells, and lysis was slightly increased by sensitization of the target cells with autologous serum. In addition to ADCC and C-mediated cytotoxicity, the specificity of anti-lymphocyte antibodies was assayed by their ability to interfere the binding of fluorescein-labelled anti-class II (HLA-DR) and anti-class I (W6/32) monoclonal antibodies to PBMC, non-T cells, P3HR-1K and Raji. Anti-class II specificity was confirmed, and antibody titres tended to be higher in Ho than in He R-AIDS, using non-T cells and Raji as targets. Higher titres of anti-class II antibodies in the Ho group could play a role in the different susceptibility of HIV-infected Ho when compared to HIV (+) He to develop AIDS. PMID:3501399

  20. Aspect-Aided Dynamic Non-Negative Sparse Representation-Based Microwave Image Classification.

    PubMed

    Zhang, Xinzheng; Yang, Qiuyue; Liu, Miaomiao; Jia, Yunjian; Liu, Shujun; Li, Guojun

    2016-01-01

    Classification of target microwave images is an important application in much areas such as security, surveillance, etc. With respect to the task of microwave image classification, a recognition algorithm based on aspect-aided dynamic non-negative least square (ADNNLS) sparse representation is proposed. Firstly, an aspect sector is determined, the center of which is the estimated aspect angle of the testing sample. The training samples in the aspect sector are divided into active atoms and inactive atoms by smooth self-representative learning. Secondly, for each testing sample, the corresponding active atoms are selected dynamically, thereby establishing dynamic dictionary. Thirdly, the testing sample is represented with ℓ 1 -regularized non-negative sparse representation under the corresponding dynamic dictionary. Finally, the class label of the testing sample is identified by use of the minimum reconstruction error. Verification of the proposed algorithm was conducted using the Moving and Stationary Target Acquisition and Recognition (MSTAR) database which was acquired by synthetic aperture radar. Experiment results validated that the proposed approach was able to capture the local aspect characteristics of microwave images effectively, thereby improving the classification performance. PMID:27598172

  1. Aspect-Aided Dynamic Non-Negative Sparse Representation-Based Microwave Image Classification

    PubMed Central

    Zhang, Xinzheng; Yang, Qiuyue; Liu, Miaomiao; Jia, Yunjian; Liu, Shujun; Li, Guojun

    2016-01-01

    Classification of target microwave images is an important application in much areas such as security, surveillance, etc. With respect to the task of microwave image classification, a recognition algorithm based on aspect-aided dynamic non-negative least square (ADNNLS) sparse representation is proposed. Firstly, an aspect sector is determined, the center of which is the estimated aspect angle of the testing sample. The training samples in the aspect sector are divided into active atoms and inactive atoms by smooth self-representative learning. Secondly, for each testing sample, the corresponding active atoms are selected dynamically, thereby establishing dynamic dictionary. Thirdly, the testing sample is represented with ℓ1-regularized non-negative sparse representation under the corresponding dynamic dictionary. Finally, the class label of the testing sample is identified by use of the minimum reconstruction error. Verification of the proposed algorithm was conducted using the Moving and Stationary Target Acquisition and Recognition (MSTAR) database which was acquired by synthetic aperture radar. Experiment results validated that the proposed approach was able to capture the local aspect characteristics of microwave images effectively, thereby improving the classification performance. PMID:27598172

  2. Progestogens’ effects and mechanisms for object recognition memory across the lifespan

    PubMed Central

    Walf, Alicia A.; Koonce, Carolyn J.; Frye, Cheryl A.

    2016-01-01

    This review explores the effects of female reproductive hormones, estrogens and progestogens, with a focus on progesterone and allopregnanolone, on object memory. Progesterone and its metabolites, in particular allopregnanolone, exert various effects on both cognitive and non-mnemonic functions in females. The well-known object recognition task is a valuable experimental paradigm that can be used to determine the effects and mechanisms of progestogens for mnemonic effects across the lifespan, which will be discussed herein. In this task there is little test-decay when different objects are used as targets and baseline valance for objects is controlled. This allows repeated testing, within-subjects designs, and longitudinal assessments, which aid understanding of changes in hormonal milieu. Objects are not aversive or food-based, which are hormone-sensitive factors. This review focuses on published data from our laboratory, and others, using the object recognition task in rodents to assess the role and mechanisms of progestogens throughout the lifespan. Improvements in object recognition performance of rodents are often associated with higher hormone levels in the hippocampus and prefrontal cortex during natural cycles, with hormone replacement following ovariectomy in young animals, or with aging. The capacity for reversal of age- and reproductive senescence-related decline in cognitive performance, and changes in neural plasticity that may be dissociated from peripheral effects with such decline, are discussed. The focus here will be on the effects of brain-derived factors, such as the neurosteroid, allopregnanolone, and other hormones, for enhancing object recognition across the lifespan. PMID:26235328

  3. Stereo vision with distance and gradient recognition

    NASA Astrophysics Data System (ADS)

    Kim, Soo-Hyun; Kang, Suk-Bum; Yang, Tae-Kyu

    2007-12-01

    Robot vision technology is needed for the stable walking, object recognition and the movement to the target spot. By some sensors which use infrared rays and ultrasonic, robot can overcome the urgent state or dangerous time. But stereo vision of three dimensional space would make robot have powerful artificial intelligence. In this paper we consider about the stereo vision for stable and correct movement of a biped robot. When a robot confront with an inclination plane or steps, particular algorithms are needed to go on without failure. This study developed the recognition algorithm of distance and gradient of environment by stereo matching process.

  4. PCA facial expression recognition

    NASA Astrophysics Data System (ADS)

    El-Hori, Inas H.; El-Momen, Zahraa K.; Ganoun, Ali

    2013-12-01

    This paper explores and compares techniques for automatically recognizing facial actions in sequences of images. The comparative study of Facial Expression Recognition (FER) techniques namely Principal Component's analysis (PCA) and PCA with Gabor filters (GF) is done. The objective of this research is to show that PCA with Gabor filters is superior to the first technique in terms of recognition rate. To test and evaluates their performance, experiments are performed using real database by both techniques. The universally accepted five principal emotions to be recognized are: Happy, Sad, Disgust and Angry along with Neutral. The recognition rates are obtained on all the facial expressions.

  5. Risk analysis. HIV / AIDS country profile: Senegal.

    PubMed

    1996-12-01

    Since the first acquired immunodeficiency syndrome (AIDS) case was confirmed in 1986, Senegal has conducted an aggressive prevention campaign. Senegal's National AIDS Committee has noted the contributions of poverty and migration to the spread of AIDS. By June 1994, 1297 AIDS cases had been reported and an estimated 500,000 people (1.4% of the population) were infected with human immunodeficiency virus (HIV)-1 and 2. The highest rate of HIV infection (14%) exists among commercial sex workers. At present, HIV/AIDS cases are concentrated in Dakar, Kaolack, the Matam region, and Ziguinchor; however, the growing importance of inter-regional trading is expected to spread HIV to the smaller towns and rural areas. Also salient is the recent devaluation by 50% of the CFA franc, which has reduced the public sector workforce and led many poor urban residents into commercial sex work. CFA devaluation has made Senegal attractive to tourists and business visitors--another factor responsible for growth of the legalized commercial sex industry. Although sex workers are instructed in condom use and tested annually for HIV, only 850 of the 2000 registered sex workers have reported for check-ups, and the majority of prostitutes are unregistered. Senegal's AIDS Plan for 1994-98 focuses on care of AIDS patients, pressures placed on family structures by HIV, and AIDS-related erosions in the status of women. Each health service region has its own local plan for AIDS/HIV and sexually transmitted diseases, supervised by a regional committee. Public education has involved outreach to religious leaders, promotion of affordable condoms, and distribution of over 75,000 leaflets to key target populations. About US $16 million of the $25,688,875-budget HIV/AIDS program for 1994-98 was pledged by external donors.

  6. RNA gymnastics in mammalian signal recognition particle assembly.

    PubMed

    Wild, Klemens; Sinning, Irmgard

    2014-01-01

    More than one third of the cellular proteome is destined for incorporation into cell membranes or export from the cell. In all domains of life, the signal recognition particle (SRP) delivers these proteins to the membrane and protein traffic falls apart without SRP logistics. With the aid of a topogenic transport signal, SRP retrieves its cargo right at the ribosome, from where they are sorted to the translocation channel. Mammalian SRP is a ribonucleoprotein complex consisting of an SRP RNA of 300 nucleotides and 6 proteins bound to it. Assembly occurs in a hierarchical manner mainly in the nucleolus and only SRP54, which recognizes the signal sequence and regulates the targeting process, is added as the last component in the cytosol. Here we present an update on recent insights in the structure, function and dynamics of SRP RNA in SRP assembly with focus on the S domain, and present SRP as an example for the complex biogenesis of a rather small ribonucleoprotein particle. PMID:25692231

  7. RNA gymnastics in mammalian signal recognition particle assembly

    PubMed Central

    Wild, Klemens; Sinning, Irmgard

    2014-01-01

    Abstract More than one third of the cellular proteome is destined for incorporation into cell membranes or export from the cell. In all domains of life, the signal recognition particle (SRP) delivers these proteins to the membrane and protein traffic falls apart without SRP logistics. With the aid of a topogenic transport signal, SRP retrieves its cargo right at the ribosome, from where they are sorted to the translocation channel. Mammalian SRP is a ribonucleoprotein complex consisting of an SRP RNA of 300 nucleotides and 6 proteins bound to it. Assembly occurs in a hierarchical manner mainly in the nucleolus and only SRP54, which recognizes the signal sequence and regulates the targeting process, is added as the last component in the cytosol. Here we present an update on recent insights in the structure, function and dynamics of SRP RNA in SRP assembly with focus on the S domain, and present SRP as an example for the complex biogenesis of a rather small ribonucleoprotein particle. PMID:25692231

  8. Pattern recognition technique

    NASA Technical Reports Server (NTRS)

    Hong, J. P.

    1971-01-01

    Technique operates regardless of pattern rotation, translation or magnification and successfully detects out-of-register patterns. It improves accuracy and reduces cost of various optical character recognition devices and page readers and provides data input to computer.

  9. Context based gait recognition

    NASA Astrophysics Data System (ADS)

    Bazazian, Shermin; Gavrilova, Marina

    2012-06-01

    Gait recognition has recently become a popular topic in the field of biometrics. However, the main hurdle is the insufficient recognition rate in the presence of low quality samples. The main focus of this paper is to investigate how the performance of a gait recognition system can be improved using additional information about behavioral patterns of users and the context in which samples have been taken. The obtained results show combining the context information with biometric data improves the performance of the system at a very low cost. The amount of improvement depends on the distinctiveness of the behavioral patterns and the quality of the gait samples. Using the appropriate distinctive behavioral models it is possible to achieve a 100% recognition rate.

  10. CASE Recognition Awards.

    ERIC Educational Resources Information Center

    Currents, 1985

    1985-01-01

    A total of 294 schools, colleges, and universities received prizes in this year's CASE Recognition program. Awards were given in: public relations programs, student recruitment, marketing, program pulications, news writing, fund raising, radio programming, school periodicals, etc. (MLW)

  11. AIDS in South Africa.

    PubMed

    Ijsselmuiden, C; Evian, C; Matjilla, J; Steinberg, M; Schneider, H

    1993-01-01

    The National AIDS Convention in South Africa (NACOSA) in October 1992 was the first real attempt to address HIV/AIDS. In Soweto, government, the African National Congress, nongovernmental organizations, and organized industry and labor representatives worked for 2 days to develop a national plan of action, but it did not result in a united effort to fight AIDS. The highest HIV infection rates in South Africa are among the KwaZulu in Natal, yet the Inkatha Freedom Party did not attend NACOSA. This episode exemplifies the key obstacles for South Africa to prevent and control AIDS. Inequality of access to health care may explain why health workers did not diagnose the first AIDS case in blacks until 1985. Migrant labor, Bantu education, and uprooted communities affect the epidemiology of HIV infection. Further, political and social polarization between blacks and whites contributes to a mindset that AIDS is limited to the other race which only diminishes the personal and collective sense of susceptibility and the volition and aptitude to act. The Department of National Health and Population Development's voluntary register of anonymously reported cases of AIDS specifies 1517 cumulative AIDS cases (October 1992), but this number is low. Seroprevalence studies show between 400,000-450,000 HIV positive cases. Public hospitals cannot give AIDS patients AZT and DDI. Few communities provided community-based care. Not all hospitals honor confidentiality and patients' need for autonomy. Even though HIV testing is not mandatory, it is required sometimes, e.g., HIV testing of immigrants. AIDS Training, Information and Counselling Centers are in urban areas, but not in poor areas where the need is most acute. The government just recently developed in AIDS education package for schools, but too many people consider it improper, so it is not being used. The poor quality education provided blacks would make it useless anyhow. Lifting of the academic boycott will allow South African

  12. Pediatric AIDS: psychosocial impact.

    PubMed

    Mangos, J A; Doran, T; Aranda-Naranjo, B; Rodriguez-Escobar, Y; Scott, A; Setzer, J R

    1990-06-01

    There is no question that the domain of the American family has been invaded by the HIV infection/AIDS epidemic. The disease, and particularly its form affecting children (pediatric AIDS), has had marked psychosocial impact on patients and families (intellectual/cognitive, emotional/behavioral, spiritual, and financial) and on our society in general (adverse or favorable). These impacts of pediatric AIDS are discussed in the present communication. PMID:2371699

  13. [Electrocardiograph beat pattern recognition].

    PubMed

    Zhou, Qunyi; Lu, Xudong; Duan, Huiling

    2005-02-01

    It is very important to recognize arrhythmia in clinical electrocardiography (ECG) analysis. The fundamental of beat pattern recognition is presented in this paper. Various prevalent methods for arrhythmia recognitiion are categorized and summarized, based on which the advantages and disadvantages among the methods are compared, and the main problems are discussed in depth. At last, the development trend of arrhythmia recognition technology is pointed out.

  14. Emotion recognition and regulation in anorexia nervosa.

    PubMed

    Harrison, Amy; Sullivan, Sarah; Tchanturia, Kate; Treasure, Janet

    2009-01-01

    It is recognized that emotional problems lie at the core of eating disorders (EDs) but scant attention has been paid to specific aspects such as emotional recognition, regulation and expression. This study aimed to investigate emotion recognition using the Reading the Mind in the Eyes (RME) task and emotion regulation using the Difficulties in Emotion Regulation Scale (DERS) in 20 women with anorexia nervosa (AN) and 20 female healthy controls (HCs). Women with AN had significantly lower scores on RME and reported significantly more difficulties with emotion regulation than HCs. There was a significant negative correlation between total DERS score and correct answers from the RME. These results suggest that women with AN have difficulties with emotional recognition and regulation. It is uncertain whether these deficits result from starvation and to what extent they might be reversed by weight gain alone. These deficits may need to be targeted in treatment.

  15. Music and Hearing Aids

    PubMed Central

    Moore, Brian C. J.

    2014-01-01

    The signal processing and fitting methods used for hearing aids have mainly been designed to optimize the intelligibility of speech. Little attention has been paid to the effectiveness of hearing aids for listening to music. Perhaps as a consequence, many hearing-aid users complain that they are not satisfied with their hearing aids when listening to music. This issue inspired the Internet-based survey presented here. The survey was designed to identify the nature and prevalence of problems associated with listening to live and reproduced music with hearing aids. Responses from 523 hearing-aid users to 21 multiple-choice questions are presented and analyzed, and the relationships between responses to questions regarding music and questions concerned with information about the respondents, their hearing aids, and their hearing loss are described. Large proportions of the respondents reported that they found their hearing aids to be helpful for listening to both live and reproduced music, although less so for the former. The survey also identified problems such as distortion, acoustic feedback, insufficient or excessive gain, unbalanced frequency response, and reduced tone quality. The results indicate that the enjoyment of listening to music with hearing aids could be improved by an increase of the input and output dynamic range, extension of the low-frequency response, and improvement of feedback cancellation and automatic gain control systems. PMID:25361601

  16. HIV / AIDS Network.

    PubMed

    1995-01-01

    The HIV/AIDS Network and the Philippines Department of Health (DOH) collaborated to produce the AIDS Candlelight Memorial at the Philippine International Convention Center (PICC), May 1995, and World AIDS Day activities on December 1, 1995. After the memorial, a fashion show, "Body Shots," provided a channel for information on acquired immunodeficiency syndrome (AIDS). On World AIDS Day, at the request of DOH, the Network provided speakers who lectured on human immunodeficiency virus (HIV) and AIDS in different government offices. Prior to World AIDS Day, the Network focused on strengthening its cohesiveness and building the capabilities of its member organizations through lectures and symposia during November. Network activities were coordinated by the Remedios AIDS Foundation with support from the other members of the Coordinating Council: Health Action Information Network (HAIN); Caritas; Kabalikat, Stop Trafficking of Pilopinos Foundation, Inc. (STOP);and the Library Foundation (TLF). The Coordinating Council elected for 1996 includes the Remedios AIDS Foundation, HAIN, Caritas, TLF, STOP, the Foundation for Adolescent Development (FAD), and the Salvation Army. PMID:12291699

  17. Music and hearing aids.

    PubMed

    Madsen, Sara M K; Moore, Brian C J

    2014-10-31

    The signal processing and fitting methods used for hearing aids have mainly been designed to optimize the intelligibility of speech. Little attention has been paid to the effectiveness of hearing aids for listening to music. Perhaps as a consequence, many hearing-aid users complain that they are not satisfied with their hearing aids when listening to music. This issue inspired the Internet-based survey presented here. The survey was designed to identify the nature and prevalence of problems associated with listening to live and reproduced music with hearing aids. Responses from 523 hearing-aid users to 21 multiple-choice questions are presented and analyzed, and the relationships between responses to questions regarding music and questions concerned with information about the respondents, their hearing aids, and their hearing loss are described. Large proportions of the respondents reported that they found their hearing aids to be helpful for listening to both live and reproduced music, although less so for the former. The survey also identified problems such as distortion, acoustic feedback, insufficient or excessive gain, unbalanced frequency response, and reduced tone quality. The results indicate that the enjoyment of listening to music with hearing aids could be improved by an increase of the input and output dynamic range, extension of the low-frequency response, and improvement of feedback cancellation and automatic gain control systems.

  18. AIDS and civil disobedience.

    PubMed

    Spiers, H R

    1989-01-01

    Members of groups such as ACT UP (AIDS Coalition to Unleash Power) risk arrest and criminal charges to protest laws and policies they view as unjust to persons with AIDS. Spiers, a founding member of ACT UP, discusses the rationale behind the tactics of civil disobedience employed by AIDS activists. He argues that civil disobedience is justified by American political and legal traditions, and by the federal government's lack of response to the needs of its citizens. Spiers warns that while AIDS protests have been nonviolent and characterized by conscientious planning and execution, violence cannot be ruled out as a "political act born of desperation."

  19. Music and hearing aids.

    PubMed

    Madsen, Sara M K; Moore, Brian C J

    2014-01-01

    The signal processing and fitting methods used for hearing aids have mainly been designed to optimize the intelligibility of speech. Little attention has been paid to the effectiveness of hearing aids for listening to music. Perhaps as a consequence, many hearing-aid users complain that they are not satisfied with their hearing aids when listening to music. This issue inspired the Internet-based survey presented here. The survey was designed to identify the nature and prevalence of problems associated with listening to live and reproduced music with hearing aids. Responses from 523 hearing-aid users to 21 multiple-choice questions are presented and analyzed, and the relationships between responses to questions regarding music and questions concerned with information about the respondents, their hearing aids, and their hearing loss are described. Large proportions of the respondents reported that they found their hearing aids to be helpful for listening to both live and reproduced music, although less so for the former. The survey also identified problems such as distortion, acoustic feedback, insufficient or excessive gain, unbalanced frequency response, and reduced tone quality. The results indicate that the enjoyment of listening to music with hearing aids could be improved by an increase of the input and output dynamic range, extension of the low-frequency response, and improvement of feedback cancellation and automatic gain control systems. PMID:25361601

  20. AIDS: Psychosocial Dimensions

    PubMed Central

    Stapleton, Dan

    1986-01-01

    In order to provide comprehensive care to patients who have AIDS, it is important for the family physician to understand the psychosocial elements of the disease. Homosexual men who have AIDS face particular problems, such as the disclosure of sexual orientation to family and friends. Issues discussed in this article include the reactions of the patient, family and friends to the diagnosis, the stigma of AIDS, the patient's support network, and preparations for disability and death. The facts about AIDS are discussed briefly, and the psychosocial implications of the illness for patients and their “significant others” are examined. The role of the family physician is highlighted. PMID:21267233