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Sample records for adaptive boosting adaboost

  1. Forward vehicle detection using cluster-based AdaBoost

    NASA Astrophysics Data System (ADS)

    Baek, Yeul-Min; Kim, Whoi-Yul

    2014-10-01

    A camera-based forward vehicle detection method with range estimation for forward collision warning system (FCWS) is presented. Previous vehicle detection methods that use conventional classifiers are not robust in a real driving environment because they lack the effectiveness of classifying vehicle samples with high intraclass variation and noise. Therefore, an improved AdaBoost, named cluster-based AdaBoost (C-AdaBoost), for classifying noisy samples along with a forward vehicle detection method are presented in this manuscript. The experiments performed consist of two parts: performance evaluations of C-AdaBoost and forward vehicle detection. The proposed C-AdaBoost shows better performance than conventional classification algorithms on the synthetic as well as various real-world datasets. In particular, when the dataset has more noisy samples, C-AdaBoost outperforms conventional classification algorithms. The proposed method is also tested with an experimental vehicle on a proving ground and on public roads, ˜62 km in length. The proposed method shows a 97% average detection rate and requires only 9.7 ms per frame. The results show the reliability of the proposed method FCWS in terms of both detection rate and processing time.

  2. The Spectrum Sensing Algorithm Based AdaBoost in Cognitive Radio

    NASA Astrophysics Data System (ADS)

    Tian, Deyong; Wang, Xin

    To solve the low detection rate of the primary user in the cognitive radio environment, we propose a spectrum sensing method based on AdaBoost in the case of low SNR. In this paper, a set of received signal spectrum features are first calculated and extracted the discriminant feature vector as training samples and testing samples for classification. Finally, we utilize the trained AdaBoost to detect the primary user. Test result shows that the proposed algorithm is not affected by uncertainty factors of noise and has high performance to classification detection compared with ANN, SVM and maximum-minimum eigenvalue (MME).

  3. Discrimination of Breast Tumors in Ultrasonic Images by Classifier Ensemble Trained with AdaBoost

    NASA Astrophysics Data System (ADS)

    Takemura, Atsushi; Shimizu, Akinobu; Hamamoto, Kazuhiko

    In this paper, we propose a novel method for acurate automated discrimination of breast tumors (carcinoma, fibroadenoma, and cyst). We defined 199 features related to diagnositic observations noticed when a doctor judges breast tumors, such as internal echo, shape, and boundary echo. These features included novel features based on a parameter of log-compressed K distribution, which reflect physical characteristics of ultrasonic B-mode imaging. Furthermore, we propose a discrimination method of breast tumors by using an ensemble classifier based on the multi-class AdaBoost algorithm with effective features selection. Verification by analyzing 200 carcinomas, 30 fibroadenomas and 30 cycts showed the usefulness of the newly defined features and the effectiveness of the discrimination by using an ensemble classifier trained by AdaBoost.

  4. Detection of coronal mass ejections using AdaBoost on grayscale statistic features

    NASA Astrophysics Data System (ADS)

    Zhang, Ling; Yin, Jian-qin; Lin, Jia-ben; Wang, Xiao-fan; Guo, Juan

    2016-10-01

    We present an automatic algorithm to detect coronal mass ejections (CMEs) in Large Angle Spectrometric Coronagraph (LASCO) C2 running difference images. The algorithm includes 3 steps: (1) split the running difference images into blocks according to slice size and analyze the grayscale statistics of the blocks from a set of images with and without CMEs; (2) select the optimal parameters for slice size, gray threshold and fraction of the bright points and (3) use AdaBoost to combine the weak classifiers designed according to the optimal parameters. Experimental results show that our method is effective and has a high accuracy rate.

  5. Classification of patterns for diffuse lung diseases in thoracic CT images by AdaBoost algorithm

    NASA Astrophysics Data System (ADS)

    Kuwahara, Masayuki; Kido, Shoji; Shouno, Hayaru

    2009-02-01

    CT images are considered as effective for differential diagnosis of diffuse lung diseases. However, the diagnosis of diffuse lung diseases is a difficult problem for the radiologists, because they show a variety of patterns on CT images. So, our purpose is to construct a computer-aided diagnosis (CAD) system for classification of patterns for diffuse lung diseases in thoracic CT images, which gives both quantitative and objective information as a second opinion, to decrease the burdens of radiologists. In this article, we propose a CAD system based on the conventional pattern recognition framework, which consists of two sub-systems; one is feature extraction part and the other is classification part. In the feature extraction part, we adopted a Gabor filter, which can extract patterns such like local edges and segments from input textures, as a feature extraction of CT images. In the recognition part, we used a boosting method. Boosting is a kind of voting method by several classifiers to improve decision precision. We applied AdaBoost algorithm for boosting method. At first, we evaluated each boosting component classifier, and we confirmed they had not enough performances in classification of patterns for diffuse lung diseases. Next, we evaluated the performance of boosting method. As a result, by use of our system, we could improve the classification rate of patterns for diffuse lung diseases.

  6. Domain adaptive boosting method and its applications

    NASA Astrophysics Data System (ADS)

    Geng, Jie; Miao, Zhenjiang

    2015-03-01

    Differences of data distributions widely exist among datasets, i.e., domains. For many pattern recognition, nature language processing, and content-based analysis systems, a decrease in performance caused by the domain differences between the training and testing datasets is still a notable problem. We propose a domain adaptation method called domain adaptive boosting (DAB). It is based on the AdaBoost approach with extensions to cover the domain differences between the source and target domains. Two main stages are contained in this approach: source-domain clustering and source-domain sample selection. By iteratively adding the selected training samples from the source domain, the discrimination model is able to achieve better domain adaptation performance based on a small validation set. The DAB algorithm is suitable for the domains with large scale samples and easy to extend for multisource adaptation. We implement this method on three computer vision systems: the skin detection model in single images, the video concept detection model, and the object classification model. In the experiments, we compare the performances of several commonly used methods and the proposed DAB. Under most situations, the DAB is superior.

  7. Region based stellate features combined with variable selection using AdaBoost learning in mammographic computer-aided detection.

    PubMed

    Kim, Dae Hoe; Choi, Jae Young; Ro, Yong Man

    2015-08-01

    In this paper, a new method is developed for extracting so-called region-based stellate features to correctly differentiate spiculated malignant masses from normal tissues on mammograms. In the proposed method, a given region of interest (ROI) for feature extraction is divided into three individual subregions, namely core, inner, and outer parts. The proposed region-based stellate features are then extracted to encode the different and complementary stellate pattern information by computing the statistical characteristics for each of the three different subregions. To further maximize classification performance, a novel variable selection algorithm based on AdaBoost learning is incorporated for choosing an optimal subset of variables of region-based stellate features. In particular, we develop a new variable selection metric (criteria) that effectively determines variable importance (ranking) within the conventional AdaBoost framework. Extensive and comparative experiments have been performed on the popular benchmark mammogram database (DB). Results show that our region-based stellate features (extracted from automatically segmented ROIs) considerably outperform other state-of-the-art features developed for mammographic spiculated mass detection or classification. Our results also indicate that combining region-based stellate features with the proposed variable selection strategy has an impressive effect on improving spiculated mass classification and detection.

  8. Geometric Feature-Based Facial Expression Recognition in Image Sequences Using Multi-Class AdaBoost and Support Vector Machines

    PubMed Central

    Ghimire, Deepak; Lee, Joonwhoan

    2013-01-01

    Facial expressions are widely used in the behavioral interpretation of emotions, cognitive science, and social interactions. In this paper, we present a novel method for fully automatic facial expression recognition in facial image sequences. As the facial expression evolves over time facial landmarks are automatically tracked in consecutive video frames, using displacements based on elastic bunch graph matching displacement estimation. Feature vectors from individual landmarks, as well as pairs of landmarks tracking results are extracted, and normalized, with respect to the first frame in the sequence. The prototypical expression sequence for each class of facial expression is formed, by taking the median of the landmark tracking results from the training facial expression sequences. Multi-class AdaBoost with dynamic time warping similarity distance between the feature vector of input facial expression and prototypical facial expression, is used as a weak classifier to select the subset of discriminative feature vectors. Finally, two methods for facial expression recognition are presented, either by using multi-class AdaBoost with dynamic time warping, or by using support vector machine on the boosted feature vectors. The results on the Cohn-Kanade (CK+) facial expression database show a recognition accuracy of 95.17% and 97.35% using multi-class AdaBoost and support vector machines, respectively. PMID:23771158

  9. Early breast cancer detection with digital mammograms using Haar-like features and AdaBoost algorithm

    NASA Astrophysics Data System (ADS)

    Zheng, Yufeng; Yang, Clifford; Merkulov, Alex; Bandari, Malavika

    2016-05-01

    The current computer-aided detection (CAD) methods are not sufficiently accurate in detecting masses, especially in dense breasts and/or small masses (typically at their early stages). A small mass may not be perceived when it is small and/or homogeneous with surrounding tissues. Possible reasons for the limited performance of existing CAD methods are lack of multiscale analysis and unification of variant masses. The speed of CAD analysis is important for field applications. We propose a new CAD model for mass detection, which extracts simple Haar-like features for fast detection, uses AdaBoost approach for feature selection and classifier training, applies cascading classifiers for reduction of false positives, and utilizes multiscale detection for variant sizes of masses. In addition to Haar features, local binary pattern (LBP) and histograms of oriented gradient (HOG) are extracted and applied to mass detection. The performance of a CAD system can be measured with true positive rate (TPR) and false positives per image (FPI). We are collecting our own digital mammograms for the proposed research. The proposed CAD model will be initially demonstrated with mass detection including architecture distortion.

  10. An AdaBoost Using a Weak-Learner Generating Several Weak-Hypotheses for Large Training Data of Natural Language Processing

    NASA Astrophysics Data System (ADS)

    Iwakura, Tomoya; Okamoto, Seishi; Asakawa, Kazuo

    AdaBoost is a method to create a final hypothesis by repeatedly generating a weak hypothesis in each training iteration with a given weak learner. AdaBoost-based algorithms are successfully applied to several tasks such as Natural Language Processing (NLP), OCR, and so on. However, learning on the training data consisting of large number of samples and features requires long training time. We propose a fast AdaBoost-based algorithm for learning rules represented by combination of features. Our algorithm constructs a final hypothesis by learning several weak-hypotheses at each iteration. We assign a confidence-rated value to each weak-hypothesis while ensuring a reduction in the theoretical upper bound of the training error of AdaBoost. We evaluate our methods with English POS tagging and text chunking. The experimental results show that the training speed of our algorithm are about 25 times faster than an AdaBoost-based learner, and about 50 times faster than Support Vector Machines with polynomial kernel on the average while maintaining state-of-the-art accuracy.

  11. Cost-sensitive AdaBoost algorithm for ordinal regression based on extreme learning machine.

    PubMed

    Riccardi, Annalisa; Fernández-Navarro, Francisco; Carloni, Sante

    2014-10-01

    In this paper, the well known stagewise additive modeling using a multiclass exponential (SAMME) boosting algorithm is extended to address problems where there exists a natural order in the targets using a cost-sensitive approach. The proposed ensemble model uses an extreme learning machine (ELM) model as a base classifier (with the Gaussian kernel and the additional regularization parameter). The closed form of the derived weighted least squares problem is provided, and it is employed to estimate analytically the parameters connecting the hidden layer to the output layer at each iteration of the boosting algorithm. Compared to the state-of-the-art boosting algorithms, in particular those using ELM as base classifier, the suggested technique does not require the generation of a new training dataset at each iteration. The adoption of the weighted least squares formulation of the problem has been presented as an unbiased and alternative approach to the already existing ELM boosting techniques. Moreover, the addition of a cost model for weighting the patterns, according to the order of the targets, enables the classifier to tackle ordinal regression problems further. The proposed method has been validated by an experimental study by comparing it with already existing ensemble methods and ELM techniques for ordinal regression, showing competitive results.

  12. Cost-sensitive AdaBoost algorithm for ordinal regression based on extreme learning machine.

    PubMed

    Riccardi, Annalisa; Fernández-Navarro, Francisco; Carloni, Sante

    2014-10-01

    In this paper, the well known stagewise additive modeling using a multiclass exponential (SAMME) boosting algorithm is extended to address problems where there exists a natural order in the targets using a cost-sensitive approach. The proposed ensemble model uses an extreme learning machine (ELM) model as a base classifier (with the Gaussian kernel and the additional regularization parameter). The closed form of the derived weighted least squares problem is provided, and it is employed to estimate analytically the parameters connecting the hidden layer to the output layer at each iteration of the boosting algorithm. Compared to the state-of-the-art boosting algorithms, in particular those using ELM as base classifier, the suggested technique does not require the generation of a new training dataset at each iteration. The adoption of the weighted least squares formulation of the problem has been presented as an unbiased and alternative approach to the already existing ELM boosting techniques. Moreover, the addition of a cost model for weighting the patterns, according to the order of the targets, enables the classifier to tackle ordinal regression problems further. The proposed method has been validated by an experimental study by comparing it with already existing ensemble methods and ELM techniques for ordinal regression, showing competitive results. PMID:25222730

  13. Combining multiple feature representations and AdaBoost ensemble learning for reducing false-positive detections in computer-aided detection of masses on mammograms.

    PubMed

    Choi, Jae Young; Kim, Dae Hoe; Plataniotis, Konstantinos N; Ro, Yong Man

    2012-01-01

    One of the drawbacks of current Computer-aided Detection (CADe) systems is a high number of false-positive (FP) detections, especially for detecting mass abnormalities. In a typical CADe system, classifier design is one of the key steps for determining FP detection rates. This paper presents the effective classifier ensemble system for tackling FP reduction problem in CADe. To construct ensemble consisting of correct classifiers while disagreeing with each other as much as possible, we develop a new ensemble construction solution that combines data resampling underpinning AdaBoost learning with the use of different feature representations. In addition, to cope with the limitation of weak classifiers in conventional AdaBoost, our method has an effective mechanism for tuning the level of weakness of base classifiers. Further, for combining multiple decision outputs of ensemble members, a weighted sum fusion strategy is used to maximize a complementary effect for correct classification. Comparative experiments have been conducted on benchmark mammogram dataset. Results show that the proposed classifier ensemble outperforms the best single classifier in terms of reducing the FP detections of masses.

  14. Object-Oriented Classification of Sugarcane Using Time-Series Middle-Resolution Remote Sensing Data Based on AdaBoost.

    PubMed

    Zhou, Zhen; Huang, Jingfeng; Wang, Jing; Zhang, Kangyu; Kuang, Zhaomin; Zhong, Shiquan; Song, Xiaodong

    2015-01-01

    Most areas planted with sugarcane are located in southern China. However, remote sensing of sugarcane has been limited because useable remote sensing data are limited due to the cloudy climate of this region during the growing season and severe spectral mixing with other crops. In this study, we developed a methodology for automatically mapping sugarcane over large areas using time-series middle-resolution remote sensing data. For this purpose, two major techniques were used, the object-oriented method (OOM) and data mining (DM). In addition, time-series Chinese HJ-1 CCD images were obtained during the sugarcane growing period. Image objects were generated using a multi-resolution segmentation algorithm, and DM was implemented using the AdaBoost algorithm, which generated the prediction model. The prediction model was applied to the HJ-1 CCD time-series image objects, and then a map of the sugarcane planting area was produced. The classification accuracy was evaluated using independent field survey sampling points. The confusion matrix analysis showed that the overall classification accuracy reached 93.6% and that the Kappa coefficient was 0.85. Thus, the results showed that this method is feasible, efficient, and applicable for extrapolating the classification of other crops in large areas where the application of high-resolution remote sensing data is impractical due to financial considerations or because qualified images are limited.

  15. Penalized linear discriminant analysis and Discrete AdaBoost to distinguish human hair metal profiles: The case of adolescents residing near Mt. Etna.

    PubMed

    Abbruzzo, A; Tamburo, E; Varrica, D; Dongarrà, G; Mineo, A

    2016-06-01

    The research focus of the present paper was twofold. First, we tried to document that human intake of trace elements is influenced by geological factors of the place of residence. Second, we showed that the elemental composition of human hair is a useful screening tool for assessing people's exposure to potentially toxic substances. For this purpose, we used samples of human hair from adolescents and applied two robust statistical approaches. Samples from two distinct geological and environmental sites were collected: the first one was characterized by the presence of the active volcano Mt. Etna (ETNA group) and the second one lithologically made up of sedimentary rocks (SIC group). Chemical data were statistically processed by Penalized Linear Discriminant Analysis (pLDA) and Discrete AdaBoost (DAB). The separation between the two groups turned out well, with few overlaps accounting for less than 5%. The chemical variables that better distinguished ETNA group from SIC group were As, Cd, Co, Li, Mo, Rb, Sr, U and V. Both pLDA and DAB allowed us to characterize the elements most closely related to the volcanic contribution (As, U and V) and those (Cd, Co, Li, Mo, Rb and Sr) prevalently influenced by the geology of the area where SIC samples were collected. We conclude that the geological characteristics of the area of residence constitute a key factor in influencing the potential exposure to trace elements. Hair analysis coupled with robust statistical methods can be effectively used as a screening procedure to identify areas at great environmental risk.

  16. Object-Oriented Classification of Sugarcane Using Time-Series Middle-Resolution Remote Sensing Data Based on AdaBoost.

    PubMed

    Zhou, Zhen; Huang, Jingfeng; Wang, Jing; Zhang, Kangyu; Kuang, Zhaomin; Zhong, Shiquan; Song, Xiaodong

    2015-01-01

    Most areas planted with sugarcane are located in southern China. However, remote sensing of sugarcane has been limited because useable remote sensing data are limited due to the cloudy climate of this region during the growing season and severe spectral mixing with other crops. In this study, we developed a methodology for automatically mapping sugarcane over large areas using time-series middle-resolution remote sensing data. For this purpose, two major techniques were used, the object-oriented method (OOM) and data mining (DM). In addition, time-series Chinese HJ-1 CCD images were obtained during the sugarcane growing period. Image objects were generated using a multi-resolution segmentation algorithm, and DM was implemented using the AdaBoost algorithm, which generated the prediction model. The prediction model was applied to the HJ-1 CCD time-series image objects, and then a map of the sugarcane planting area was produced. The classification accuracy was evaluated using independent field survey sampling points. The confusion matrix analysis showed that the overall classification accuracy reached 93.6% and that the Kappa coefficient was 0.85. Thus, the results showed that this method is feasible, efficient, and applicable for extrapolating the classification of other crops in large areas where the application of high-resolution remote sensing data is impractical due to financial considerations or because qualified images are limited. PMID:26528811

  17. Object-Oriented Classification of Sugarcane Using Time-Series Middle-Resolution Remote Sensing Data Based on AdaBoost

    PubMed Central

    Zhou, Zhen; Huang, Jingfeng; Wang, Jing; Zhang, Kangyu; Kuang, Zhaomin; Zhong, Shiquan; Song, Xiaodong

    2015-01-01

    Most areas planted with sugarcane are located in southern China. However, remote sensing of sugarcane has been limited because useable remote sensing data are limited due to the cloudy climate of this region during the growing season and severe spectral mixing with other crops. In this study, we developed a methodology for automatically mapping sugarcane over large areas using time-series middle-resolution remote sensing data. For this purpose, two major techniques were used, the object-oriented method (OOM) and data mining (DM). In addition, time-series Chinese HJ-1 CCD images were obtained during the sugarcane growing period. Image objects were generated using a multi-resolution segmentation algorithm, and DM was implemented using the AdaBoost algorithm, which generated the prediction model. The prediction model was applied to the HJ-1 CCD time-series image objects, and then a map of the sugarcane planting area was produced. The classification accuracy was evaluated using independent field survey sampling points. The confusion matrix analysis showed that the overall classification accuracy reached 93.6% and that the Kappa coefficient was 0.85. Thus, the results showed that this method is feasible, efficient, and applicable for extrapolating the classification of other crops in large areas where the application of high-resolution remote sensing data is impractical due to financial considerations or because qualified images are limited. PMID:26528811

  18. Penalized linear discriminant analysis and Discrete AdaBoost to distinguish human hair metal profiles: The case of adolescents residing near Mt. Etna.

    PubMed

    Abbruzzo, A; Tamburo, E; Varrica, D; Dongarrà, G; Mineo, A

    2016-06-01

    The research focus of the present paper was twofold. First, we tried to document that human intake of trace elements is influenced by geological factors of the place of residence. Second, we showed that the elemental composition of human hair is a useful screening tool for assessing people's exposure to potentially toxic substances. For this purpose, we used samples of human hair from adolescents and applied two robust statistical approaches. Samples from two distinct geological and environmental sites were collected: the first one was characterized by the presence of the active volcano Mt. Etna (ETNA group) and the second one lithologically made up of sedimentary rocks (SIC group). Chemical data were statistically processed by Penalized Linear Discriminant Analysis (pLDA) and Discrete AdaBoost (DAB). The separation between the two groups turned out well, with few overlaps accounting for less than 5%. The chemical variables that better distinguished ETNA group from SIC group were As, Cd, Co, Li, Mo, Rb, Sr, U and V. Both pLDA and DAB allowed us to characterize the elements most closely related to the volcanic contribution (As, U and V) and those (Cd, Co, Li, Mo, Rb and Sr) prevalently influenced by the geology of the area where SIC samples were collected. We conclude that the geological characteristics of the area of residence constitute a key factor in influencing the potential exposure to trace elements. Hair analysis coupled with robust statistical methods can be effectively used as a screening procedure to identify areas at great environmental risk. PMID:27015569

  19. Adaptive Replanning to Account for Lumpectomy Cavity Change in Sequential Boost After Whole-Breast Irradiation

    SciTech Connect

    Chen, Xiaojian; Qiao, Qiao; DeVries, Anthony; Li, Wenhui; Currey, Adam; Kelly, Tracy; Bergom, Carmen; Wilson, J. Frank; Li, X. Allen

    2014-12-01

    Purpose: To evaluate the efficiency of standard image-guided radiation therapy (IGRT) to account for lumpectomy cavity (LC) variation during whole-breast irradiation (WBI) and propose an adaptive strategy to improve dosimetry if IGRT fails to address the interfraction LC variations. Methods and Materials: Daily diagnostic-quality CT data acquired during IGRT in the boost stage using an in-room CT for 19 breast cancer patients treated with sequential boost after WBI in the prone position were retrospectively analyzed. Contours of the LC, treated breast, ipsilateral lung, and heart were generated by populating contours from planning CTs to boost fraction CTs using an auto-segmentation tool with manual editing. Three plans were generated on each fraction CT: (1) a repositioning plan by applying the original boost plan with the shift determined by IGRT; (2) an adaptive plan by modifying the original plan according to a fraction CT; and (3) a reoptimization plan by a full-scale optimization. Results: Significant variations were observed in LC. The change in LC volume at the first boost fraction ranged from a 70% decrease to a 50% increase of that on the planning CT. The adaptive and reoptimization plans were comparable. Compared with the repositioning plans, the adaptive plans led to an improvement in target coverage for an increased LC case (1 of 19, 7.5% increase in planning target volume evaluation volume V{sub 95%}), and breast tissue sparing for an LC decrease larger than 35% (3 of 19, 7.5% decrease in breast evaluation volume V{sub 50%}; P=.008). Conclusion: Significant changes in LC shape and volume at the time of boost that deviate from the original plan for WBI with sequential boost can be addressed by adaptive replanning at the first boost fraction.

  20. Online Adaboost-Based Parameterized Methods for Dynamic Distributed Network Intrusion Detection.

    PubMed

    Hu, Weiming; Gao, Jun; Wang, Yanguo; Wu, Ou; Maybank, Stephen

    2014-01-01

    Current network intrusion detection systems lack adaptability to the frequently changing network environments. Furthermore, intrusion detection in the new distributed architectures is now a major requirement. In this paper, we propose two online Adaboost-based intrusion detection algorithms. In the first algorithm, a traditional online Adaboost process is used where decision stumps are used as weak classifiers. In the second algorithm, an improved online Adaboost process is proposed, and online Gaussian mixture models (GMMs) are used as weak classifiers. We further propose a distributed intrusion detection framework, in which a local parameterized detection model is constructed in each node using the online Adaboost algorithm. A global detection model is constructed in each node by combining the local parametric models using a small number of samples in the node. This combination is achieved using an algorithm based on particle swarm optimization (PSO) and support vector machines. The global model in each node is used to detect intrusions. Experimental results show that the improved online Adaboost process with GMMs obtains a higher detection rate and a lower false alarm rate than the traditional online Adaboost process that uses decision stumps. Both the algorithms outperform existing intrusion detection algorithms. It is also shown that our PSO, and SVM-based algorithm effectively combines the local detection models into the global model in each node; the global model in a node can handle the intrusion types that are found in other nodes, without sharing the samples of these intrusion types. PMID:23757534

  1. Online boosting for vehicle detection.

    PubMed

    Chang, Wen-Chung; Cho, Chih-Wei

    2010-06-01

    This paper presents a real-time vision-based vehicle detection system employing an online boosting algorithm. It is an online AdaBoost approach for a cascade of strong classifiers instead of a single strong classifier. Most existing cascades of classifiers must be trained offline and cannot effectively be updated when online tuning is required. The idea is to develop a cascade of strong classifiers for vehicle detection that is capable of being online trained in response to changing traffic environments. To make the online algorithm tractable, the proposed system must efficiently tune parameters based on incoming images and up-to-date performance of each weak classifier. The proposed online boosting method can improve system adaptability and accuracy to deal with novel types of vehicles and unfamiliar environments, whereas existing offline methods rely much more on extensive training processes to reach comparable results and cannot further be updated online. Our approach has been successfully validated in real traffic environments by performing experiments with an onboard charge-coupled-device camera in a roadway vehicle.

  2. Stable detection of expanded target by the use of boosting random ferns

    NASA Astrophysics Data System (ADS)

    Deng, Li; Wang, Chunhong; Rao, Changhui

    2012-10-01

    This paper studies the problem of keypoints recognition of extended target which lacks of texture information, and introduces an approach of stable detection of these targets called boosting random ferns (BRF). As common descriptors in this circumstance do not work as well as usual cases, matching of keypoints is hence turned into classification task so as to make use of the trainable characteristic of classifier. The kernel of BRF is consisted of random ferns as the classifier and AdaBoost (Adaptive Boosting) as the frame so that accuracy of random ferns classifier can be boosted to a relatively high level. Experiments compare BRF with widely used SURF descriptor and single random ferns classifier. The result shows that BRF obtains higher recognition rate of keypoints. Besides, for image sequence, BRF provides stronger stability than SURF in target detection, which proves the efficiency of BRF aiming to extended target which lacks of texture information.

  3. Optimization of Adaboost Algorithm for Sonar Target Detection in a Multi-Stage ATR System

    NASA Technical Reports Server (NTRS)

    Lin, Tsung Han (Hank)

    2011-01-01

    JPL has developed a multi-stage Automated Target Recognition (ATR) system to locate objects in images. First, input images are preprocessed and sent to a Grayscale Optical Correlator (GOC) filter to identify possible regions-of-interest (ROIs). Second, feature extraction operations are performed using Texton filters and Principal Component Analysis (PCA). Finally, the features are fed to a classifier, to identify ROIs that contain the targets. Previous work used the Feed-forward Back-propagation Neural Network for classification. In this project we investigate a version of Adaboost as a classifier for comparison. The version we used is known as GentleBoost. We used the boosted decision tree as the weak classifier. We have tested our ATR system against real-world sonar images using the Adaboost approach. Results indicate an improvement in performance over a single Neural Network design.

  4. Deployment of spatial attention without moving the eyes is boosted by oculomotor adaptation

    PubMed Central

    Habchi, Ouazna; Rey, Elodie; Mathieu, Romain; Urquizar, Christian; Farnè, Alessandro; Pélisson, Denis

    2015-01-01

    Vertebrates developed sophisticated solutions to select environmental visual information, being capable of moving attention without moving the eyes. A large body of behavioral and neuroimaging studies indicate a tight coupling between eye movements and spatial attention. The nature of this link, however, remains highly debated. Here, we demonstrate that deployment of human covert attention, measured in stationary eye conditions, can be boosted across space by changing the size of ocular saccades to a single position via a specific adaptation paradigm. These findings indicate that spatial attention is more widely affected by oculomotor plasticity than previously thought. PMID:26300755

  5. Optimization of Prime-Boost Vaccination Strategies Against Mouse-Adapted Ebolavirus in a Short-Term Protection Study.

    PubMed

    Aviles, Jenna; Bello, Alexander; Wong, Gary; Fausther-Bovendo, Hugues; Qiu, Xiangguo; Kobinger, Gary

    2015-10-01

    In nonhuman primates, complete protection against an Ebola virus (EBOV) challenge has previously been achieved after a single injection with several vaccine platforms. However, long-term protection against EBOV after a single immunization has not been demonstrated to this date. Interestingly, prime-boost regimens have demonstrated longer protection against EBOV challenge, compared with single immunizations. Since prime-boost regimens have the potential to achieve long-term protection, determining optimal vector combinations is crucial. However, testing prime-boost efficiency in long-term protection studies is time consuming and resource demanding. Here, we investigated the optimal prime-boost combination, using DNA, porcine-derived adeno-associated virus serotype 6 (AAV-po6), and human adenovirus serotype 5 (Ad5) vector, in a short-term protection study in the mouse model of EBOV infection. In addition, we also investigated which immune parameters were indicative of a strong boost. Each vaccine platform was titrated in mice to identify which dose (single immunization) induced approximately 20% protection after challenge with a mouse-adapted EBOV. These doses were then used to determine the protection efficacy of various prime-boost combinations, using the same mouse model. In addition, humoral and cellular immune responses against EBOV glycoprotein were analyzed by an enzyme-linked immunosorbent assay, a neutralizing antibody assay, and an interferon γ-specific enzyme-linked immunospot assay. When DNA was used as a prime, Ad5 boost induced the best protection, which correlated with a higher cellular response. In contrast, when AAV-po6 or Ad5 were injected first, better protection was achieved after DNA boost, and this correlated with a higher total glycoprotein-specific immunoglobulin G titer. Prime-boost regimens using independent vaccine platforms may provide a useful strategy to induce long-term immune protection against filoviruses.

  6. Optimization of Prime-Boost Vaccination Strategies Against Mouse-Adapted Ebolavirus in a Short-Term Protection Study.

    PubMed

    Aviles, Jenna; Bello, Alexander; Wong, Gary; Fausther-Bovendo, Hugues; Qiu, Xiangguo; Kobinger, Gary

    2015-10-01

    In nonhuman primates, complete protection against an Ebola virus (EBOV) challenge has previously been achieved after a single injection with several vaccine platforms. However, long-term protection against EBOV after a single immunization has not been demonstrated to this date. Interestingly, prime-boost regimens have demonstrated longer protection against EBOV challenge, compared with single immunizations. Since prime-boost regimens have the potential to achieve long-term protection, determining optimal vector combinations is crucial. However, testing prime-boost efficiency in long-term protection studies is time consuming and resource demanding. Here, we investigated the optimal prime-boost combination, using DNA, porcine-derived adeno-associated virus serotype 6 (AAV-po6), and human adenovirus serotype 5 (Ad5) vector, in a short-term protection study in the mouse model of EBOV infection. In addition, we also investigated which immune parameters were indicative of a strong boost. Each vaccine platform was titrated in mice to identify which dose (single immunization) induced approximately 20% protection after challenge with a mouse-adapted EBOV. These doses were then used to determine the protection efficacy of various prime-boost combinations, using the same mouse model. In addition, humoral and cellular immune responses against EBOV glycoprotein were analyzed by an enzyme-linked immunosorbent assay, a neutralizing antibody assay, and an interferon γ-specific enzyme-linked immunospot assay. When DNA was used as a prime, Ad5 boost induced the best protection, which correlated with a higher cellular response. In contrast, when AAV-po6 or Ad5 were injected first, better protection was achieved after DNA boost, and this correlated with a higher total glycoprotein-specific immunoglobulin G titer. Prime-boost regimens using independent vaccine platforms may provide a useful strategy to induce long-term immune protection against filoviruses. PMID:26038398

  7. Dose Escalation for Locally Advanced Lung Cancer Using Adaptive Radiation Therapy With Simultaneous Integrated Volume-Adapted Boost

    SciTech Connect

    Weiss, Elisabeth; Fatyga, Mirek; Wu, Yan; Dogan, Nesrin; Balik, Salim; Sleeman, William; Hugo, Geoffrey

    2013-07-01

    Purpose: To test the feasibility of a planned phase 1 study of image-guided adaptive radiation therapy in locally advanced lung cancer. Methods and Materials: Weekly 4-dimensional fan beam computed tomographs (4D FBCT) of 10 lung cancer patients undergoing concurrent chemoradiation therapy were used to simulate adaptive radiation therapy: After an initial intensity modulated radiation therapy plan (0-30 Gy/2 Gy), adaptive replanning was performed on week 2 (30-50 Gy/2 Gy) and week 4 scans (50-66 Gy/2 Gy) to adjust for volume and shape changes of primary tumors and lymph nodes. Week 2 and 4 clinical target volumes (CTV) were deformably warped from the initial planning scan to adjust for anatomical changes. On the week 4 scan, a simultaneous integrated volume-adapted boost was created to the shrunken primary tumor with dose increases in 5 0.4-Gy steps from 66 Gy to 82 Gy in 2 scenarios: plan A, lung isotoxicity; plan B, normal tissue tolerance. Cumulative dose was assessed by deformably mapping and accumulating biologically equivalent dose normalized to 2 Gy-fractions (EQD2). Results: The 82-Gy level was achieved in 1 in 10 patients in scenario A, resulting in a 13.4-Gy EQD2 increase and a 22.1% increase in tumor control probability (TCP) compared to the 66-Gy plan. In scenario B, 2 patients reached the 82-Gy level with a 13.9 Gy EQD2 and 23.4% TCP increase. Conclusions: The tested image-guided adaptive radiation therapy strategy enabled relevant increases in EQD2 and TCP. Normal tissue was often dose limiting, indicating a need to modify the present study design before clinical implementation.

  8. Dose Escalation for Locally Advanced Lung Cancer using Adaptive Radiotherapy with Simultaneous Integrated Volume-Adapted Boost

    PubMed Central

    Weiss, Elisabeth; Fatyga, Mirek; Wu, Yan; Dogan, Nesrin; Balik, Salim; Sleeman, William; Hugo, Geoffrey

    2013-01-01

    Purpose Test the feasibility of a planned phase I study of image-guided adaptive radiotherapy in locally advanced lung cancer. Methods and Materials Weekly 4D FBCTs of ten lung cancer patients undergoing concurrent radiochemotherapy were used to simulate adaptive radiotherapy: After an initial IMRT plan (0–30 Gy/2 Gy), adaptive replanning was performed on week 2 (30 to 50 Gy/2 Gy) and week 4 scans (50 to 66 Gy/2 Gy) to adjust for volume and shape changes of primary tumors and lymph nodes. Week 2 and 4 clinical target volumes (CTV) were deformably warped from the initial planning scan to adjust for anatomical changes. On week 4 scan a simultaneous integrated volume-adapted boost was created to the shrunken PT with dose increases in five 0.4 Gy steps from 66 Gy to 82 Gy in two scenarios: Plan A. lung isotoxicity and B. normal tissue tolerance. Cumulative dose was assessed by deformably mapping and accumulating biologically equivalent dose normalized to 2 Gy-fractions (EQD2). Results The 82 Gy level was achieved in 1/10 patients in scenario A resulting in a 13.4 Gy EQD2 increase and a 22.1% increase in tumor control probability (TCP) compared to the 66 Gy plan. In scenario B, 2 patients reached the 82 Gy level with a 13.9 Gy EQD2 and 23.4% TCP increase. Conclusions The tested IGART strategy enabled relevant increases in EQD2 and TCP. Normal tissue was often dose limiting, indicating a need to modify the present study design prior to clinical implementation. PMID:23523321

  9. SU-F-BRF-07: Impact of Different Patient Setup Strategies in Adaptive Radiation Therapy with Simultaneous Integrated Volume-Adapted Boost of NSCLC

    SciTech Connect

    Balik, S; Weiss, E; Sleeman, W; Wu, Y; Hugo, G; Dogan, N; Fatyga, M

    2014-06-15

    Purpose: To evaluate the potential impact of several setup error correction strategies on a proposed image-guided adaptive radiotherapy strategy for locally advanced lung cancer. Methods: Daily 4D cone-beam CT and weekly 4D fan-beam CT images were acquired from 9 lung cancer patients undergoing concurrent chemoradiation therapy. Initial planning CT was deformably registered to daily CBCT images to generate synthetic treatment courses. An adaptive radiation therapy course was simulated using the weekly CT images with replanning twice and a hypofractionated, simultaneous integrated boost to a total dose of 66 Gy to the original PTV and either a 66 Gy (no boost) or 82 Gy (boost) dose to the boost PTV (ITV + 3mm) in 33 fractions with IMRT or VMAT. Lymph nodes (LN) were not boosted (prescribed to 66 Gy in both plans). Synthetic images were rigidly, bony (BN) or tumor and carina (TC), registered to the corresponding plan CT, dose was computed on these from adaptive replans (PLAN) and deformably accumulated back to the original planning CT. Cumulative D98% of CTV of PT (ITV for 82Gy) and LN, and normal tissue dose changes were analyzed. Results: Two patients were removed from the study due to large registration errors. For the remaining 7 patients, D98% for CTV-PT (ITV-PT for 82 Gy) and CTV-LN was within 1 Gy of PLAN for both 66 Gy and 82 Gy plans with both setup techniques. Overall, TC based setup provided better results, especially for LN coverage (p = 0.1 for 66Gy plan and p = 0.2 for 82 Gy plan, comparison of BN and TC), though not significant. Normal tissue dose constraints violated for some patients if constraint was barely achieved in PLAN. Conclusion: The hypofractionated adaptive strategy appears to be deliverable with soft tissue alignment for the evaluated margins and planning parameters. Research was supported by NIH P01CA116602.

  10. Reinforced adaboost face detector using support vector machine

    NASA Astrophysics Data System (ADS)

    Jang, Jaeyoon; Yunkoo, C.; Jaehong, K.; Yoon, Hosub

    2014-08-01

    We propose a novel face detection algorithm in order to improve higher detection rate of face-detector than conventional haar - adaboost face detector. Our purposed method not only improves detection rate of a face but decreases the number of false-positive component. In order to get improved detection ability, we merged two classifiers: adaboost and support vector machine. Because SVM and Adaboost use different feature, they are complementary each other. We can get 2~4% improved performance using proposed method than previous our detector that is not applied proposed method. This method makes improved detector that shows better performance without algorithm replacement.

  11. Visual tracking by separability-maximum boosting

    NASA Astrophysics Data System (ADS)

    Hou, Jie; Mao, Yao-bin; Sun, Jin-sheng

    2013-10-01

    Recently, visual tracking has been formulated as a classification problem whose task is to detect the object from the scene with a binary classifier. Boosting based online feature selection methods, which adopt the classifier to appearance changes by choosing the most discriminative features, have been demonstrated to be effective for visual tracking. A major problem of such online feature selection methods is that an inaccurate classifier may give imprecise tracking windows. Tracking error accumulates when the tracker trains the classifier with misaligned samples and finally leads to drifting. Separability-maximum boosting (SMBoost), an alternative form of AdaBoost which characterizes the separability between the object and the scene by their means and covariance matrices, is proposed. SMBoost only needs the means and covariance matrices during training and can be easily adopted to online learning problems by estimating the statistics incrementally. Experiment on UCI machine learning datasets shows that SMBoost is as accurate as offline AdaBoost, and significantly outperforms Oza's online boosting. Accurate classifier stabilizes the tracker on challenging video sequences. Empirical results also demonstrate improvements in term of tracking precision and speed, comparing ours to those state-of-the-art ones.

  12. Real-Time Road Sign Detection Using Fuzzy-Boosting

    NASA Astrophysics Data System (ADS)

    Yoon, Changyong; Lee, Heejin; Kim, Euntai; Park, Mignon

    This paper describes a vision-based and real-time system for detecting road signs from within a moving vehicle. The system architecture which is proposed in this paper consists of two parts, the learning and the detection part of road sign images. The proposed system has the standard architecture with adaboost algorithm. Adaboost is a popular algorithm which used to detect an object in real time. To improve the detection rate of adaboost algorithm, this paper proposes a new combination method of classifiers in every stage. In the case of detecting road signs in real environment, it can be ambiguous to decide to which class input images belong. To overcome this problem, we propose a method that applies fuzzy measure and fuzzy integral which use the importance and the evaluated values of classifiers within one stage. It is called fuzzy-boosting in this paper. Also, to improve the speed of a road sign detection algorithm using adaboost at the detection step, we propose a method which chooses several candidates by using MC generator. In this paper, as the sub-windows of chosen candidates pass classifiers which are made from fuzzy-boosting, we decide whether a road sign is detected or not. Using experiment result, we analyze and compare the detection speed and the classification error rate of the proposed algorithm applied to various environment and condition.

  13. Cost-Sensitive Boosting: Fitting an Additive Asymmetric Logistic Regression Model

    NASA Astrophysics Data System (ADS)

    Li, Qiu-Jie; Mao, Yao-Bin; Wang, Zhi-Quan; Xiang, Wen-Bo

    Conventional machine learning algorithms like boosting tend to equally treat misclassification errors that are not adequate to process certain cost-sensitive classification problems such as object detection. Although many cost-sensitive extensions of boosting by directly modifying the weighting strategy of correspond original algorithms have been proposed and reported, they are heuristic in nature and only proved effective by empirical results but lack sound theoretical analysis. This paper develops a framework from a statistical insight that can embody almost all existing cost-sensitive boosting algorithms: fitting an additive asymmetric logistic regression model by stage-wise optimization of certain criterions. Four cost-sensitive versions of boosting algorithms are derived, namely CSDA, CSRA, CSGA and CSLB which respectively correspond to Discrete AdaBoost, Real AdaBoost, Gentle AdaBoost and LogitBoost. Experimental results on the application of face detection have shown the effectiveness of the proposed learning framework in the reduction of the cumulative misclassification cost.

  14. Towards incorporating affective computing to virtual rehabilitation; surrogating attributed attention from posture for boosting therapy adaptation

    NASA Astrophysics Data System (ADS)

    Rivas, Jesús J.; Heyer, Patrick; Orihuela-Espina, Felipe; Sucar, Luis Enrique

    2015-01-01

    Virtual rehabilitation (VR) is a novel motor rehabilitation therapy in which the rehabilitation exercises occurs through interaction with bespoken virtual environments. These virtual environments dynamically adapt their activity to match the therapy progress. Adaptation should be guided by the cognitive and emotional state of the patient, none of which are directly observable. Here, we present our first steps towards inferring non-observable attentional state from unobtrusively observable seated posture, so that this knowledge can later be exploited by a VR platform to modulate its behaviour. The space of seated postures was discretized and 648 pictures of acted representations were exposed to crowd-evaluation to determine attributed state of attention. A semi-supervised classifier based on Na¨ıve Bayes with structural improvement was learnt to unfold a predictive relation between posture and attributed attention. Internal validity was established following a 2×5 cross-fold strategy. Following 4959 votes from crowd, classification accuracy reached a promissory 96.29% (µ±σ = 87.59±6.59) and F-measure reached 82.35% (µ ± σ = 69.72 ± 10.50). With the afforded rate of classification, we believe it is safe to claim posture as a reliable proxy for attributed attentional state. It follows that unobtrusively monitoring posture can be exploited for guiding an intelligent adaptation in a virtual rehabilitation platform. This study further helps to identify critical aspects of posture permitting inference of attention.

  15. Improving ensemble decision tree performance using Adaboost and Bagging

    NASA Astrophysics Data System (ADS)

    Hasan, Md. Rajib; Siraj, Fadzilah; Sainin, Mohd Shamrie

    2015-12-01

    Ensemble classifier systems are considered as one of the most promising in medical data classification and the performance of deceision tree classifier can be increased by the ensemble method as it is proven to be better than single classifiers. However, in a ensemble settings the performance depends on the selection of suitable base classifier. This research employed two prominent esemble s namely Adaboost and Bagging with base classifiers such as Random Forest, Random Tree, j48, j48grafts and Logistic Model Regression (LMT) that have been selected independently. The empirical study shows that the performance varries when different base classifiers are selected and even some places overfitting issue also been noted. The evidence shows that ensemble decision tree classfiers using Adaboost and Bagging improves the performance of selected medical data sets.

  16. Face detection in complex background based on Adaboost algorithm and YCbCr skin color model

    NASA Astrophysics Data System (ADS)

    Ge, Wei; Han, Chunling; Quan, Wei

    2015-12-01

    Face detection is a fundamental and important research theme in the topic of Pattern Recognition and Computer Vision. Now, remarkable fruits have been achieved. Among these methods, statistics based methods hold a dominant position. In this paper, Adaboost algorithm based on Haar-like features is used to detect faces in complex background. The method combining YCbCr skin model detection and Adaboost is researched, the skin detection method is used to validate the detection results obtained by Adaboost algorithm. It overcomes false detection problem by Adaboost. Experimental results show that nearly all non-face areas are removed, and improve the detection rate.

  17. AdaBoost-based algorithm for network intrusion detection.

    PubMed

    Hu, Weiming; Hu, Wei; Maybank, Steve

    2008-04-01

    Network intrusion detection aims at distinguishing the attacks on the Internet from normal use of the Internet. It is an indispensable part of the information security system. Due to the variety of network behaviors and the rapid development of attack fashions, it is necessary to develop fast machine-learning-based intrusion detection algorithms with high detection rates and low false-alarm rates. In this correspondence, we propose an intrusion detection algorithm based on the AdaBoost algorithm. In the algorithm, decision stumps are used as weak classifiers. The decision rules are provided for both categorical and continuous features. By combining the weak classifiers for continuous features and the weak classifiers for categorical features into a strong classifier, the relations between these two different types of features are handled naturally, without any forced conversions between continuous and categorical features. Adaptable initial weights and a simple strategy for avoiding overfitting are adopted to improve the performance of the algorithm. Experimental results show that our algorithm has low computational complexity and error rates, as compared with algorithms of higher computational complexity, as tested on the benchmark sample data. PMID:18348941

  18. Gentle Nearest Neighbors Boosting over Proper Scoring Rules.

    PubMed

    Nock, Richard; Ali, Wafa Bel Haj; D'Ambrosio, Roberto; Nielsen, Frank; Barlaud, Michel

    2015-01-01

    Tailoring nearest neighbors algorithms to boosting is an important problem. Recent papers study an approach, UNN, which provably minimizes particular convex surrogates under weak assumptions. However, numerical issues make it necessary to experimentally tweak parts of the UNN algorithm, at the possible expense of the algorithm's convergence and performance. In this paper, we propose a lightweight Newton-Raphson alternative optimizing proper scoring rules from a very broad set, and establish formal convergence rates under the boosting framework that compete with those known for UNN. To the best of our knowledge, no such boosting-compliant convergence rates were previously known in the popular Gentle Adaboost's lineage. We provide experiments on a dozen domains, including Caltech and SUN computer vision databases, comparing our approach to major families including support vector machines, (Ada)boosting and stochastic gradient descent. They support three major conclusions: (i) GNNB significantly outperforms UNN, in terms of convergence rate and quality of the outputs, (ii) GNNB performs on par with or better than computationally intensive large margin approaches, (iii) on large domains that rule out those latter approaches for computational reasons, GNNB provides a simple and competitive contender to stochastic gradient descent. Experiments include a divide-and-conquer improvement of GNNB exploiting the link with proper scoring rules optimization. PMID:26353210

  19. Feasibility of an Adaptive Strategy in Preoperative Radiochemotherapy for Rectal Cancer With Image-Guided Tomotherapy: Boosting the Dose to the Shrinking Tumor

    SciTech Connect

    Passoni, Paolo; Fiorino, Claudio; Slim, Najla; Ronzoni, Monica; Ricci, Vincenzo; Di Palo, Saverio; De Nardi, Paola; Orsenigo, Elena; Tamburini, Andrea; De Cobelli, Francesco; Losio, Claudio; Iacovelli, Nicola A.; Broggi, Sara; Staudacher, Carlo; Calandrino, Riccardo; Di Muzio, Nadia

    2013-09-01

    Purpose: To investigate the feasibility of preoperative adaptive radiochemotherapy by delivering a concomitant boost to the residual tumor during the last 6 fractions of treatment. Methods and Materials: Twenty-five patients with T3/T4N0 or N+ rectal cancer were enrolled. Concomitant chemotherapy consisted of oxaliplatin 100 mg/m{sup 2} on days −14, 0, and +14, and 5-fluorouracil 200 mg/m{sup 2}/d from day −14 to the end of radiation therapy (day 0 is the start of radiation therapy). Radiation therapy consisted of 41.4 Gy in 18 fractions (2.3 Gy per fraction) with Tomotherapy to the tumor and regional lymph nodes (planning target volume, PTV) defined on simulation CT and MRI. After 9 fractions simulation CT and MRI were repeated for the planning of the adaptive phase: PTV{sub adapt} was generated by adding a 5-mm margin to the residual tumor. In the last 6 fractions a boost of 3.0 Gy per fraction (in total 45.6 Gy in 18 fractions) was delivered to PTV{sub adapt} while concomitantly delivering 2.3 Gy per fraction to PTV outside PTV{sub adapt}. Results: Three patients experienced grade 3 gastrointestinal toxicity; 2 of 3 showed toxicity before the adaptive phase. Full dose of radiation therapy, oxaliplatin, and 5-fluorouracil was delivered in 96%, 96%, and 88% of patients, respectively. Two patients with clinical complete response (cCR) refused surgery and were still cCR at 17 and 29 months. For the remaining 23 resected patients, 15 of 23 (65%) showed tumor regression grade 3 response, and 7 of 23 (30%) had pathologic complete response; 8 (35%) and 12 (52%) tumor regression grade 3 patients had ≤5% and 10% residual viable cells, respectively. Conclusions: An adaptive boost strategy is feasible, with an acceptable grade 3 gastrointestinal toxicity rate and a very encouraging tumor response rate. The results suggest that there should still be room for further dose escalation of the residual tumor with the aim of increasing pathologic complete response and/or c

  20. Application of adaptive boosting to EP-derived multilayer feed-forward neural networks (MLFN) to improve benign/malignant breast cancer classification

    NASA Astrophysics Data System (ADS)

    Land, Walker H., Jr.; Masters, Timothy D.; Lo, Joseph Y.; McKee, Dan

    2001-07-01

    A new neural network technology was developed for improving the benign/malignant diagnosis of breast cancer using mammogram findings. A new paradigm, Adaptive Boosting (AB), uses a markedly different theory in solutioning Computational Intelligence (CI) problems. AB, a new machine learning paradigm, focuses on finding weak learning algorithm(s) that initially need to provide slightly better than random performance (i.e., approximately 55%) when processing a mammogram training set. Then, by successive development of additional architectures (using the mammogram training set), the adaptive boosting process improves the performance of the basic Evolutionary Programming derived neural network architectures. The results of these several EP-derived hybrid architectures are then intelligently combined and tested using a similar validation mammogram data set. Optimization focused on improving specificity and positive predictive value at very high sensitivities, where an analysis of the performance of the hybrid would be most meaningful. Using the DUKE mammogram database of 500 biopsy proven samples, on average this hybrid was able to achieve (under statistical 5-fold cross-validation) a specificity of 48.3% and a positive predictive value (PPV) of 51.8% while maintaining 100% sensitivity. At 97% sensitivity, a specificity of 56.6% and a PPV of 55.8% were obtained.

  1. Key-text spotting in documentary videos using Adaboost

    NASA Astrophysics Data System (ADS)

    Lalonde, M.; Gagnon, L.

    2006-02-01

    This paper presents a method for spotting key-text in videos, based on a cascade of classifiers trained with Adaboost. The video is first reduced to a set of key-frames. Each key-frame is then analyzed for its text content. Text spotting is performed by scanning the image with a variable-size window (to account for scale) within which simple features (mean/variance of grayscale values and x/y derivatives) are extracted in various sub-areas. Training builds classifiers using the most discriminant spatial combinations of features for text detection. The text-spotting module outputs a decision map of the size of the input key-frame showing regions of interest that may contain text suitable for recognition by an OCR system. Performance is measured against a dataset of 147 key-frames extracted from 22 documentary films of the National Film Board (NFB) of Canada. A detection rate of 97% is obtained with relatively few false alarms.

  2. A 0.04 mm (2) Buck-Boost DC-DC Converter for Biomedical Implants Using Adaptive Gain and Discrete Frequency Scaling Control.

    PubMed

    George, Libin; Gargiulo, Gaetano Dario; Lehmann, Torsten; Hamilton, Tara Julia

    2016-06-01

    This paper presents the design of a reconfigurable buck-boost switched-capacitor DC-DC converter suitable for use in a wide range of biomedical implants. The proposed converter has an extremely small footprint and uses a novel control method that allows coarse and fine control of the output voltage. The converter uses adaptive gain control, discrete frequency scaling and pulse-skipping schemes to regulate the power delivered to a range of output voltages and loads. Adaptive gain control is used to implement variable switching gain ratios from a reconfigurable power stage and thereby make coarse steps in output voltage. A discrete frequency scaling controller makes discrete changes in switching frequency to vary the power delivered to the load and perform fine tuning when the output voltage is within 10% of the target output voltage. The control architecture is predominately digital and it has been implemented as part of a fully-integrated switched-capacitor converter design using a standard bulk CMOS 0.18 μm process. Measured results show that the converter has an output voltage range of 1.0 to 2.2 V, can deliver up to 7.5 mW of load power and efficiency up to 75% using an active area of only 0.04 mm (2), which is significantly smaller than that of other designs. This low-area, low-complexity reconfigurable power converter can support low-power circuits in biomedical implant applications. PMID:26600247

  3. A 0.04 mm (2) Buck-Boost DC-DC Converter for Biomedical Implants Using Adaptive Gain and Discrete Frequency Scaling Control.

    PubMed

    George, Libin; Gargiulo, Gaetano Dario; Lehmann, Torsten; Hamilton, Tara Julia

    2016-06-01

    This paper presents the design of a reconfigurable buck-boost switched-capacitor DC-DC converter suitable for use in a wide range of biomedical implants. The proposed converter has an extremely small footprint and uses a novel control method that allows coarse and fine control of the output voltage. The converter uses adaptive gain control, discrete frequency scaling and pulse-skipping schemes to regulate the power delivered to a range of output voltages and loads. Adaptive gain control is used to implement variable switching gain ratios from a reconfigurable power stage and thereby make coarse steps in output voltage. A discrete frequency scaling controller makes discrete changes in switching frequency to vary the power delivered to the load and perform fine tuning when the output voltage is within 10% of the target output voltage. The control architecture is predominately digital and it has been implemented as part of a fully-integrated switched-capacitor converter design using a standard bulk CMOS 0.18 μm process. Measured results show that the converter has an output voltage range of 1.0 to 2.2 V, can deliver up to 7.5 mW of load power and efficiency up to 75% using an active area of only 0.04 mm (2), which is significantly smaller than that of other designs. This low-area, low-complexity reconfigurable power converter can support low-power circuits in biomedical implant applications.

  4. Automatic face detection and tracking based on Adaboost with camshift algorithm

    NASA Astrophysics Data System (ADS)

    Lin, Hui; Long, JianFeng

    2011-10-01

    With the development of information technology, video surveillance is widely used in security monitoring and identity recognition. For most of pure face tracking algorithms are hard to specify the initial location and scale of face automatically, this paper proposes a fast and robust method to detect and track face by combining adaboost with camshift algorithm. At first, the location and scale of face is specified by adaboost algorithm based on Haar-like features and it will be conveyed to the initial search window automatically. Then, we apply camshift algorithm to track face. The experimental results based on OpenCV software yield good results, even in some special circumstances, such as light changing and face rapid movement. Besides, by drawing out the tracking trajectory of face movement, some abnormal behavior events can be analyzed.

  5. Model Vestibular Nuclei Neurons Can Exhibit a Boosting Nonlinearity Due to an Adaptation Current Regulated by Spike-Triggered Calcium and Calcium-Activated Potassium Channels.

    PubMed

    Schneider, Adam D

    2016-01-01

    In vitro studies have previously found a class of vestibular nuclei neurons to exhibit a bidirectional afterhyperpolarization (AHP) in their membrane potential, due to calcium and calcium-activated potassium conductances. More recently in vivo studies of such vestibular neurons were found to exhibit a boosting nonlinearity in their input-output tuning curves. In this paper, a Hodgkin-Huxley (HH) type neuron model, originally developed to reproduce the in vitro AHP, is shown to produce a boosting nonlinearity similar to that seen in vivo for increased the calcium conductance. Indicative of a bifurcation, the HH model is reduced to a generalized integrate-and-fire (IF) model that preserves the bifurcation structure and boosting nonliearity. By then projecting the neuron model's phase space trajectories into 2D, the underlying geometric mechanism relating the AHP and boosting nonlinearity is revealed. Further simplifications and approximations are made to derive analytic expressions for the steady steady state firing rate as a function of bias current, μ, as well as the gain (i.e. its slope) and the position of its peak at μ = μ*. Finally, although the boosting nonlinearity has not yet been experimentally observed in vitro, testable predictions indicate how it might be found. PMID:27427914

  6. Model Vestibular Nuclei Neurons Can Exhibit a Boosting Nonlinearity Due to an Adaptation Current Regulated by Spike-Triggered Calcium and Calcium-Activated Potassium Channels

    PubMed Central

    Schneider, Adam D.

    2016-01-01

    In vitro studies have previously found a class of vestibular nuclei neurons to exhibit a bidirectional afterhyperpolarization (AHP) in their membrane potential, due to calcium and calcium-activated potassium conductances. More recently in vivo studies of such vestibular neurons were found to exhibit a boosting nonlinearity in their input-output tuning curves. In this paper, a Hodgkin-Huxley (HH) type neuron model, originally developed to reproduce the in vitro AHP, is shown to produce a boosting nonlinearity similar to that seen in vivo for increased the calcium conductance. Indicative of a bifurcation, the HH model is reduced to a generalized integrate-and-fire (IF) model that preserves the bifurcation structure and boosting nonliearity. By then projecting the neuron model’s phase space trajectories into 2D, the underlying geometric mechanism relating the AHP and boosting nonlinearity is revealed. Further simplifications and approximations are made to derive analytic expressions for the steady steady state firing rate as a function of bias current, μ, as well as the gain (i.e. its slope) and the position of its peak at μ = μ*. Finally, although the boosting nonlinearity has not yet been experimentally observed in vitro, testable predictions indicate how it might be found. PMID:27427914

  7. Joint sulcal detection on cortical surfaces with graphical models and boosted priors.

    PubMed

    Shi, Yonggang; Tu, Zhuowen; Reiss, Allan L; Dutton, Rebecca A; Lee, Agatha D; Galaburda, Albert M; Dinov, Ivo; Thompson, Paul M; Toga, Arthur W

    2009-03-01

    In this paper, we propose an automated approach for the joint detection of major sulci on cortical surfaces. By representing sulci as nodes in a graphical model, we incorporate Markovian relations between sulci and formulate their detection as a maximum a posteriori (MAP) estimation problem over the joint space of major sulci. To make the inference tractable, a sample space with a finite number of candidate curves is automatically generated at each node based on the Hamilton-Jacobi skeleton of sulcal regions. Using the AdaBoost algorithm, we learn both individual and pairwise shape priors of sulcal curves from training data, which are then used to define potential functions in the graphical model based on the connection between AdaBoost and logistic regression. Finally belief propagation is used to perform the MAP inference and select the joint detection results from the sample spaces of candidate curves. In our experiments, we quantitatively validate our algorithm with manually traced curves and demonstrate the automatically detected curves can capture the main body of sulci very accurately. A comparison with independently detected results is also conducted to illustrate the advantage of the joint detection approach. PMID:19244008

  8. An Adaboost-Backpropagation Neural Network for Automated Image Sentiment Classification

    PubMed Central

    Cao, Jianfang; Chen, Junjie; Li, Haifang

    2014-01-01

    The development of multimedia technology and the popularisation of image capture devices have resulted in the rapid growth of digital images. The reliance on advanced technology to extract and automatically classify the emotional semantics implicit in images has become a critical problem. We proposed an emotional semantic classification method for images based on the Adaboost-backpropagation (BP) neural network, using natural scenery images as examples. We described image emotions using the Ortony, Clore, and Collins emotion model and constructed a strong classifier by integrating 15 outputs of a BP neural network based on the Adaboost algorithm. The objective of the study was to improve the efficiency of emotional image classification. Using 600 natural scenery images downloaded from the Baidu photo channel to train and test the model, our experiments achieved results superior to the results obtained using the BP neural network method. The accuracy rate increased by approximately 15% compared with the method previously reported in the literature. The proposed method provides a foundation for the development of additional automatic sentiment image classification methods and demonstrates practical value. PMID:25162047

  9. Boosting Shift-Invariant Features

    NASA Astrophysics Data System (ADS)

    Hörnlein, Thomas; Jähne, Bernd

    This work presents a novel method for training shift-invariant features using a Boosting framework. Features performing local convolutions followed by subsampling are used to achieve shift-invariance. Other systems using this type of features, e.g. Convolutional Neural Networks, use complex feed-forward networks with multiple layers. In contrast, the proposed system adds features one at a time using smoothing spline base classifiers. Feature training optimizes base classifier costs. Boosting sample-reweighting ensures features to be both descriptive and independent. Our system has a lower number of design parameters as comparable systems, so adapting the system to new problems is simple. Also, the stage-wise training makes it very scalable. Experimental results show the competitiveness of our approach.

  10. A boosted optimal linear learner for retinal vessel segmentation

    NASA Astrophysics Data System (ADS)

    Poletti, E.; Grisan, E.

    2014-03-01

    Ocular fundus images provide important information about retinal degeneration, which may be related to acute pathologies or to early signs of systemic diseases. An automatic and quantitative assessment of vessel morphological features, such as diameters and tortuosity, can improve clinical diagnosis and evaluation of retinopathy. At variance with available methods, we propose a data-driven approach, in which the system learns a set of optimal discriminative convolution kernels (linear learner). The set is progressively built based on an ADA-boost sample weighting scheme, providing seamless integration between linear learner estimation and classification. In order to capture the vessel appearance changes at different scales, the kernels are estimated on a pyramidal decomposition of the training samples. The set is employed as a rotating bank of matched filters, whose response is used by the boosted linear classifier to provide a classification of each image pixel into the two classes of interest (vessel/background). We tested the approach fundus images available from the DRIVE dataset. We show that the segmentation performance yields an accuracy of 0.94.

  11. Face detection using beta wavelet filter and cascade classifier entrained with Adaboost

    NASA Astrophysics Data System (ADS)

    Afdhal, Rim; Bahar, Akram; Ejbali, Ridha; Zaied, Mourad

    2015-12-01

    Face detection has been one of the most studied topics in the computer vision literature due to its relevant role in applications such as video surveillance, human computer interface and face image database management. Here, we will present a face detection approach which contains two steps. The first step is training phase based on Adaboost algorithm. The second step is the detection phase. The proposed approach presents an enhancement of Viola and Jones' algorithm by replacing Haar descriptors with Beta wavelet. The obtained results have proved an excellent performance of detection not only when a face is in front of the camera but also when it is oriented towards the right or the left. Moreover, thanks to the start period needed for the detection, our approach can be applied during a real time experience.

  12. Robust Ground Target Detection by SAR and IR Sensor Fusion Using Adaboost-Based Feature Selection

    PubMed Central

    Kim, Sungho; Song, Woo-Jin; Kim, So-Hyun

    2016-01-01

    Long-range ground targets are difficult to detect in a noisy cluttered environment using either synthetic aperture radar (SAR) images or infrared (IR) images. SAR-based detectors can provide a high detection rate with a high false alarm rate to background scatter noise. IR-based approaches can detect hot targets but are affected strongly by the weather conditions. This paper proposes a novel target detection method by decision-level SAR and IR fusion using an Adaboost-based machine learning scheme to achieve a high detection rate and low false alarm rate. The proposed method consists of individual detection, registration, and fusion architecture. This paper presents a single framework of a SAR and IR target detection method using modified Boolean map visual theory (modBMVT) and feature-selection based fusion. Previous methods applied different algorithms to detect SAR and IR targets because of the different physical image characteristics. One method that is optimized for IR target detection produces unsuccessful results in SAR target detection. This study examined the image characteristics and proposed a unified SAR and IR target detection method by inserting a median local average filter (MLAF, pre-filter) and an asymmetric morphological closing filter (AMCF, post-filter) into the BMVT. The original BMVT was optimized to detect small infrared targets. The proposed modBMVT can remove the thermal and scatter noise by the MLAF and detect extended targets by attaching the AMCF after the BMVT. Heterogeneous SAR and IR images were registered automatically using the proposed RANdom SAmple Region Consensus (RANSARC)-based homography optimization after a brute-force correspondence search using the detected target centers and regions. The final targets were detected by feature-selection based sensor fusion using Adaboost. The proposed method showed good SAR and IR target detection performance through feature selection-based decision fusion on a synthetic database generated

  13. Robust Ground Target Detection by SAR and IR Sensor Fusion Using Adaboost-Based Feature Selection.

    PubMed

    Kim, Sungho; Song, Woo-Jin; Kim, So-Hyun

    2016-01-01

    Long-range ground targets are difficult to detect in a noisy cluttered environment using either synthetic aperture radar (SAR) images or infrared (IR) images. SAR-based detectors can provide a high detection rate with a high false alarm rate to background scatter noise. IR-based approaches can detect hot targets but are affected strongly by the weather conditions. This paper proposes a novel target detection method by decision-level SAR and IR fusion using an Adaboost-based machine learning scheme to achieve a high detection rate and low false alarm rate. The proposed method consists of individual detection, registration, and fusion architecture. This paper presents a single framework of a SAR and IR target detection method using modified Boolean map visual theory (modBMVT) and feature-selection based fusion. Previous methods applied different algorithms to detect SAR and IR targets because of the different physical image characteristics. One method that is optimized for IR target detection produces unsuccessful results in SAR target detection. This study examined the image characteristics and proposed a unified SAR and IR target detection method by inserting a median local average filter (MLAF, pre-filter) and an asymmetric morphological closing filter (AMCF, post-filter) into the BMVT. The original BMVT was optimized to detect small infrared targets. The proposed modBMVT can remove the thermal and scatter noise by the MLAF and detect extended targets by attaching the AMCF after the BMVT. Heterogeneous SAR and IR images were registered automatically using the proposed RANdom SAmple Region Consensus (RANSARC)-based homography optimization after a brute-force correspondence search using the detected target centers and regions. The final targets were detected by feature-selection based sensor fusion using Adaboost. The proposed method showed good SAR and IR target detection performance through feature selection-based decision fusion on a synthetic database generated

  14. Robust Ground Target Detection by SAR and IR Sensor Fusion Using Adaboost-Based Feature Selection.

    PubMed

    Kim, Sungho; Song, Woo-Jin; Kim, So-Hyun

    2016-07-19

    Long-range ground targets are difficult to detect in a noisy cluttered environment using either synthetic aperture radar (SAR) images or infrared (IR) images. SAR-based detectors can provide a high detection rate with a high false alarm rate to background scatter noise. IR-based approaches can detect hot targets but are affected strongly by the weather conditions. This paper proposes a novel target detection method by decision-level SAR and IR fusion using an Adaboost-based machine learning scheme to achieve a high detection rate and low false alarm rate. The proposed method consists of individual detection, registration, and fusion architecture. This paper presents a single framework of a SAR and IR target detection method using modified Boolean map visual theory (modBMVT) and feature-selection based fusion. Previous methods applied different algorithms to detect SAR and IR targets because of the different physical image characteristics. One method that is optimized for IR target detection produces unsuccessful results in SAR target detection. This study examined the image characteristics and proposed a unified SAR and IR target detection method by inserting a median local average filter (MLAF, pre-filter) and an asymmetric morphological closing filter (AMCF, post-filter) into the BMVT. The original BMVT was optimized to detect small infrared targets. The proposed modBMVT can remove the thermal and scatter noise by the MLAF and detect extended targets by attaching the AMCF after the BMVT. Heterogeneous SAR and IR images were registered automatically using the proposed RANdom SAmple Region Consensus (RANSARC)-based homography optimization after a brute-force correspondence search using the detected target centers and regions. The final targets were detected by feature-selection based sensor fusion using Adaboost. The proposed method showed good SAR and IR target detection performance through feature selection-based decision fusion on a synthetic database generated

  15. [State Recognition of Solid Fermentation Process Based on Near Infrared Spectroscopy with Adaboost and Spectral Regression Discriminant Analysis].

    PubMed

    Yu, Shuang; Liu, Guo-hai; Xia, Rong-sheng; Jiang, Hui

    2016-01-01

    In order to achieve the rapid monitoring of process state of solid state fermentation (SSF), this study attempted to qualitative identification of process state of SSF of feed protein by use of Fourier transform near infrared (FT-NIR) spectroscopy analysis technique. Even more specifically, the FT-NIR spectroscopy combined with Adaboost-SRDA-NN integrated learning algorithm as an ideal analysis tool was used to accurately and rapidly monitor chemical and physical changes in SSF of feed protein without the need for chemical analysis. Firstly, the raw spectra of all the 140 fermentation samples obtained were collected by use of Fourier transform near infrared spectrometer (Antaris II), and the raw spectra obtained were preprocessed by use of standard normal variate transformation (SNV) spectral preprocessing algorithm. Thereafter, the characteristic information of the preprocessed spectra was extracted by use of spectral regression discriminant analysis (SRDA). Finally, nearest neighbors (NN) algorithm as a basic classifier was selected and building state recognition model to identify different fermentation samples in the validation set. Experimental results showed as follows: the SRDA-NN model revealed its superior performance by compared with other two different NN models, which were developed by use of the feature information form principal component analysis (PCA) and linear discriminant analysis (LDA), and the correct recognition rate of SRDA-NN model achieved 94.28% in the validation set. In this work, in order to further improve the recognition accuracy of the final model, Adaboost-SRDA-NN ensemble learning algorithm was proposed by integrated the Adaboost and SRDA-NN methods, and the presented algorithm was used to construct the online monitoring model of process state of SSF of feed protein. Experimental results showed as follows: the prediction performance of SRDA-NN model has been further enhanced by use of Adaboost lifting algorithm, and the correct

  16. Performance Boosting Additive

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Mainstream Engineering Corporation was awarded Phase I and Phase II contracts from Goddard Space Flight Center's Small Business Innovation Research (SBIR) program in early 1990. With support from the SBIR program, Mainstream Engineering Corporation has developed a unique low cost additive, QwikBoost (TM), that increases the performance of air conditioners, heat pumps, refrigerators, and freezers. Because of the energy and environmental benefits of QwikBoost, Mainstream received the Tibbetts Award at a White House Ceremony on October 16, 1997. QwikBoost was introduced at the 1998 International Air Conditioning, Heating, and Refrigeration Exposition. QwikBoost is packaged in a handy 3-ounce can (pressurized with R-134a) and will be available for automotive air conditioning systems in summer 1998.

  17. Obscenity detection using haar-like features and Gentle Adaboost classifier.

    PubMed

    Mustafa, Rashed; Min, Yang; Zhu, Dingju

    2014-01-01

    Large exposure of skin area of an image is considered obscene. This only fact may lead to many false images having skin-like objects and may not detect those images which have partially exposed skin area but have exposed erotogenic human body parts. This paper presents a novel method for detecting nipples from pornographic image contents. Nipple is considered as an erotogenic organ to identify pornographic contents from images. In this research Gentle Adaboost (GAB) haar-cascade classifier and haar-like features used for ensuring detection accuracy. Skin filter prior to detection made the system more robust. The experiment showed that, considering accuracy, haar-cascade classifier performs well, but in order to satisfy detection time, train-cascade classifier is suitable. To validate the results, we used 1198 positive samples containing nipple objects and 1995 negative images. The detection rates for haar-cascade and train-cascade classifiers are 0.9875 and 0.8429, respectively. The detection time for haar-cascade is 0.162 seconds and is 0.127 seconds for train-cascade classifier. PMID:25003153

  18. Obscenity Detection Using Haar-Like Features and Gentle Adaboost Classifier

    PubMed Central

    Min, Yang; Zhu, Dingju

    2014-01-01

    Large exposure of skin area of an image is considered obscene. This only fact may lead to many false images having skin-like objects and may not detect those images which have partially exposed skin area but have exposed erotogenic human body parts. This paper presents a novel method for detecting nipples from pornographic image contents. Nipple is considered as an erotogenic organ to identify pornographic contents from images. In this research Gentle Adaboost (GAB) haar-cascade classifier and haar-like features used for ensuring detection accuracy. Skin filter prior to detection made the system more robust. The experiment showed that, considering accuracy, haar-cascade classifier performs well, but in order to satisfy detection time, train-cascade classifier is suitable. To validate the results, we used 1198 positive samples containing nipple objects and 1995 negative images. The detection rates for haar-cascade and train-cascade classifiers are 0.9875 and 0.8429, respectively. The detection time for haar-cascade is 0.162 seconds and is 0.127 seconds for train-cascade classifier. PMID:25003153

  19. Classification of 5-HT1A Receptor Ligands on the Basis of Their Binding Affinities by Using PSO-Adaboost-SVM

    PubMed Central

    Cheng, Zhengjun; Zhang, Yuntao; Zhou, Changhong; Zhang, Wenjun; Gao, Shibo

    2009-01-01

    In the present work, the support vector machine (SVM) and Adaboost-SVM have been used to develop a classification model as a potential screening mechanism for a novel series of 5-HT1A selective ligands. Each compound is represented by calculated structural descriptors that encode topological features. The particle swarm optimization (PSO) and the stepwise multiple linear regression (Stepwise-MLR) methods have been used to search descriptor space and select the descriptors which are responsible for the inhibitory activity of these compounds. The model containing seven descriptors found by Adaboost-SVM, has showed better predictive capability than the other models. The total accuracy in prediction for the training and test set is 100.0% and 95.0% for PSO-Adaboost-SVM, 99.1% and 92.5% for PSO-SVM, 99.1% and 82.5% for Stepwise-MLR-Adaboost-SVM, 99.1% and 77.5% for Stepwise-MLR-SVM, respectively. The results indicate that Adaboost-SVM can be used as a useful modeling tool for QSAR studies. PMID:20111683

  20. Online Bagging and Boosting

    NASA Technical Reports Server (NTRS)

    Oza, Nikunji C.

    2005-01-01

    Bagging and boosting are two of the most well-known ensemble learning methods due to their theoretical performance guarantees and strong experimental results. However, these algorithms have been used mainly in batch mode, i.e., they require the entire training set to be available at once and, in some cases, require random access to the data. In this paper, we present online versions of bagging and boosting that require only one pass through the training data. We build on previously presented work by presenting some theoretical results. We also compare the online and batch algorithms experimentally in terms of accuracy and running time.

  1. Octane boosting catalyst

    SciTech Connect

    Miller, J.G.; Pellet, R.J.; Shamshoun, E.S.; Rabo, J.A

    1989-02-07

    The invention provides petroleum cracking and octane boosting catalysts containing a composite of an intermediate pore NZMS in combination with another non-zeolitic molecular sieve having the same framework structure, and processes for cracking of petroleum for the purpose of enhancing the octane rating of the gasoline produced.

  2. Remote Sensing Data Binary Classification Using Boosting with Simple Classifiers

    NASA Astrophysics Data System (ADS)

    Nowakowski, Artur

    2015-10-01

    Boosting is a classification method which has been proven useful in non-satellite image processing while it is still new to satellite remote sensing. It is a meta-algorithm, which builds a strong classifier from many weak ones in iterative way. We adapt the AdaBoost.M1 boosting algorithm in a new land cover classification scenario based on utilization of very simple threshold classifiers employing spectral and contextual information. Thresholds for the classifiers are automatically calculated adaptively to data statistics. The proposed method is employed for the exemplary problem of artificial area identification. Classification of IKONOS multispectral data results in short computational time and overall accuracy of 94.4% comparing to 94.0% obtained by using AdaBoost.M1 with trees and 93.8% achieved using Random Forest. The influence of a manipulation of the final threshold of the strong classifier on classification results is reported.

  3. Adapt

    NASA Astrophysics Data System (ADS)

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  4. Learning object location predictors with boosting and grammar-guided feature extraction

    SciTech Connect

    Eads, Damian Ryan; Rosten, Edward; Helmbold, David

    2009-01-01

    The authors present BEAMER: a new spatially exploitative approach to learning object detectors which shows excellent results when applied to the task of detecting objects in greyscale aerial imagery in the presence of ambiguous and noisy data. There are four main contributions used to produce these results. First, they introduce a grammar-guided feature extraction system, enabling the exploration of a richer feature space while constraining the features to a useful subset. This is specified with a rule-based generative grammer crafted by a human expert. Second, they learn a classifier on this data using a newly proposed variant of AdaBoost which takes into account the spatially correlated nature of the data. Third, they perform another round of training to optimize the method of converting the pixel classifications generated by boosting into a high quality set of (x,y) locations. lastly, they carefully define three common problems in object detection and define two evaluation criteria that are tightly matched to these problems. Major strengths of this approach are: (1) a way of randomly searching a broad feature space, (2) its performance when evaluated on well-matched evaluation criteria, and (3) its use of the location prediction domain to learn object detectors as well as to generate detections that perform well on several tasks: object counting, tracking, and target detection. They demonstrate the efficacy of BEAMER with a comprehensive experimental evaluation on a challenging data set.

  5. Effect of training characteristics on object classification: An application using Boosted Decision Trees

    NASA Astrophysics Data System (ADS)

    Sevilla-Noarbe, I.; Etayo-Sotos, P.

    2015-06-01

    We present an application of a particular machine-learning method (Boosted Decision Trees, BDTs using AdaBoost) to separate stars and galaxies in photometric images using their catalog characteristics. BDTs are a well established machine learning technique used for classification purposes. They have been widely used specially in the field of particle and astroparticle physics, and we use them here in an optical astronomy application. This algorithm is able to improve from simple thresholding cuts on standard separation variables that may be affected by local effects such as blending, badly calculated background levels or which do not include information in other bands. The improvements are shown using the Sloan Digital Sky Survey Data Release 9, with respect to the type photometric classifier. We obtain an improvement in the impurity of the galaxy sample of a factor 2-4 for this particular dataset, adjusting for the same efficiency of the selection. Another main goal of this study is to verify the effects that different input vectors and training sets have on the classification performance, the results being of wider use to other machine learning techniques.

  6. Gradient boosting machines, a tutorial

    PubMed Central

    Natekin, Alexey; Knoll, Alois

    2013-01-01

    Gradient boosting machines are a family of powerful machine-learning techniques that have shown considerable success in a wide range of practical applications. They are highly customizable to the particular needs of the application, like being learned with respect to different loss functions. This article gives a tutorial introduction into the methodology of gradient boosting methods with a strong focus on machine learning aspects of modeling. A theoretical information is complemented with descriptive examples and illustrations which cover all the stages of the gradient boosting model design. Considerations on handling the model complexity are discussed. Three practical examples of gradient boosting applications are presented and comprehensively analyzed. PMID:24409142

  7. Analytic boosted boson discrimination

    NASA Astrophysics Data System (ADS)

    Larkoski, Andrew J.; Moult, Ian; Neill, Duff

    2016-05-01

    Observables which discriminate boosted topologies from massive QCD jets are of great importance for the success of the jet substructure program at the Large Hadron Collider. Such observables, while both widely and successfully used, have been studied almost exclusively with Monte Carlo simulations. In this paper we present the first all-orders factorization theorem for a two-prong discriminant based on a jet shape variable, D 2, valid for both signal and background jets. Our factorization theorem simultaneously describes the production of both collinear and soft subjets, and we introduce a novel zero-bin procedure to correctly describe the transition region between these limits. By proving an all orders factorization theorem, we enable a systematically improvable description, and allow for precision comparisons between data, Monte Carlo, and first principles QCD calculations for jet substructure observables. Using our factorization theorem, we present numerical results for the discrimination of a boosted Z boson from massive QCD background jets. We compare our results with Monte Carlo predictions which allows for a detailed understanding of the extent to which these generators accurately describe the formation of two-prong QCD jets, and informs their usage in substructure analyses. Our calculation also provides considerable insight into the discrimination power and calculability of jet substructure observables in general.

  8. Analytic boosted boson discrimination

    DOE PAGES

    Larkoski, Andrew J.; Moult, Ian; Neill, Duff

    2016-05-20

    Observables which discriminate boosted topologies from massive QCD jets are of great importance for the success of the jet substructure program at the Large Hadron Collider. Such observables, while both widely and successfully used, have been studied almost exclusively with Monte Carlo simulations. In this paper we present the first all-orders factorization theorem for a two-prong discriminant based on a jet shape variable, D2, valid for both signal and background jets. Our factorization theorem simultaneously describes the production of both collinear and soft subjets, and we introduce a novel zero-bin procedure to correctly describe the transition region between these limits.more » By proving an all orders factorization theorem, we enable a systematically improvable description, and allow for precision comparisons between data, Monte Carlo, and first principles QCD calculations for jet substructure observables. Using our factorization theorem, we present numerical results for the discrimination of a boosted Z boson from massive QCD background jets. We compare our results with Monte Carlo predictions which allows for a detailed understanding of the extent to which these generators accurately describe the formation of two-prong QCD jets, and informs their usage in substructure analyses. In conclusion, our calculation also provides considerable insight into the discrimination power and calculability of jet substructure observables in general.« less

  9. Bidirectional buck boost converter

    DOEpatents

    Esser, Albert Andreas Maria

    1998-03-31

    A bidirectional buck boost converter and method of operating the same allows regulation of power flow between first and second voltage sources in which the voltage level at each source is subject to change and power flow is independent of relative voltage levels. In one embodiment, the converter is designed for hard switching while another embodiment implements soft switching of the switching devices. In both embodiments, first and second switching devices are serially coupled between a relatively positive terminal and a relatively negative terminal of a first voltage source with third and fourth switching devices serially coupled between a relatively positive terminal and a relatively negative terminal of a second voltage source. A free-wheeling diode is coupled, respectively, in parallel opposition with respective ones of the switching devices. An inductor is coupled between a junction of the first and second switching devices and a junction of the third and fourth switching devices. Gating pulses supplied by a gating circuit selectively enable operation of the switching devices for transferring power between the voltage sources. In the second embodiment, each switching device is shunted by a capacitor and the switching devices are operated when voltage across the device is substantially zero.

  10. Bidirectional buck boost converter

    DOEpatents

    Esser, A.A.M.

    1998-03-31

    A bidirectional buck boost converter and method of operating the same allows regulation of power flow between first and second voltage sources in which the voltage level at each source is subject to change and power flow is independent of relative voltage levels. In one embodiment, the converter is designed for hard switching while another embodiment implements soft switching of the switching devices. In both embodiments, first and second switching devices are serially coupled between a relatively positive terminal and a relatively negative terminal of a first voltage source with third and fourth switching devices serially coupled between a relatively positive terminal and a relatively negative terminal of a second voltage source. A free-wheeling diode is coupled, respectively, in parallel opposition with respective ones of the switching devices. An inductor is coupled between a junction of the first and second switching devices and a junction of the third and fourth switching devices. Gating pulses supplied by a gating circuit selectively enable operation of the switching devices for transferring power between the voltage sources. In the second embodiment, each switching device is shunted by a capacitor and the switching devices are operated when voltage across the device is substantially zero. 20 figs.

  11. EEG classification for motor imagery and resting state in BCI applications using multi-class Adaboost extreme learning machine.

    PubMed

    Gao, Lin; Cheng, Wei; Zhang, Jinhua; Wang, Jue

    2016-08-01

    Brain-computer interface (BCI) systems provide an alternative communication and control approach for people with limited motor function. Therefore, the feature extraction and classification approach should differentiate the relative unusual state of motion intention from a common resting state. In this paper, we sought a novel approach for multi-class classification in BCI applications. We collected electroencephalographic (EEG) signals registered by electrodes placed over the scalp during left hand motor imagery, right hand motor imagery, and resting state for ten healthy human subjects. We proposed using the Kolmogorov complexity (Kc) for feature extraction and a multi-class Adaboost classifier with extreme learning machine as base classifier for classification, in order to classify the three-class EEG samples. An average classification accuracy of 79.5% was obtained for ten subjects, which greatly outperformed commonly used approaches. Thus, it is concluded that the proposed method could improve the performance for classification of motor imagery tasks for multi-class samples. It could be applied in further studies to generate the control commands to initiate the movement of a robotic exoskeleton or orthosis, which finally facilitates the rehabilitation of disabled people.

  12. EEG classification for motor imagery and resting state in BCI applications using multi-class Adaboost extreme learning machine

    NASA Astrophysics Data System (ADS)

    Gao, Lin; Cheng, Wei; Zhang, Jinhua; Wang, Jue

    2016-08-01

    Brain-computer interface (BCI) systems provide an alternative communication and control approach for people with limited motor function. Therefore, the feature extraction and classification approach should differentiate the relative unusual state of motion intention from a common resting state. In this paper, we sought a novel approach for multi-class classification in BCI applications. We collected electroencephalographic (EEG) signals registered by electrodes placed over the scalp during left hand motor imagery, right hand motor imagery, and resting state for ten healthy human subjects. We proposed using the Kolmogorov complexity (Kc) for feature extraction and a multi-class Adaboost classifier with extreme learning machine as base classifier for classification, in order to classify the three-class EEG samples. An average classification accuracy of 79.5% was obtained for ten subjects, which greatly outperformed commonly used approaches. Thus, it is concluded that the proposed method could improve the performance for classification of motor imagery tasks for multi-class samples. It could be applied in further studies to generate the control commands to initiate the movement of a robotic exoskeleton or orthosis, which finally facilitates the rehabilitation of disabled people.

  13. EEG classification for motor imagery and resting state in BCI applications using multi-class Adaboost extreme learning machine.

    PubMed

    Gao, Lin; Cheng, Wei; Zhang, Jinhua; Wang, Jue

    2016-08-01

    Brain-computer interface (BCI) systems provide an alternative communication and control approach for people with limited motor function. Therefore, the feature extraction and classification approach should differentiate the relative unusual state of motion intention from a common resting state. In this paper, we sought a novel approach for multi-class classification in BCI applications. We collected electroencephalographic (EEG) signals registered by electrodes placed over the scalp during left hand motor imagery, right hand motor imagery, and resting state for ten healthy human subjects. We proposed using the Kolmogorov complexity (Kc) for feature extraction and a multi-class Adaboost classifier with extreme learning machine as base classifier for classification, in order to classify the three-class EEG samples. An average classification accuracy of 79.5% was obtained for ten subjects, which greatly outperformed commonly used approaches. Thus, it is concluded that the proposed method could improve the performance for classification of motor imagery tasks for multi-class samples. It could be applied in further studies to generate the control commands to initiate the movement of a robotic exoskeleton or orthosis, which finally facilitates the rehabilitation of disabled people. PMID:27587163

  14. Representing Arbitrary Boosts for Undergraduates.

    ERIC Educational Resources Information Center

    Frahm, Charles P.

    1979-01-01

    Presented is a derivation for the matrix representation of an arbitrary boost, a Lorentz transformation without rotation, suitable for undergraduate students with modest backgrounds in mathematics and relativity. The derivation uses standard vector and matrix techniques along with the well-known form for a special Lorentz transformation. (BT)

  15. Interferometric resolution boosting for spectrographs

    SciTech Connect

    Erskine, D J; Edelstein, J

    2004-05-25

    Externally dispersed interferometry (EDI) is a technique for enhancing the performance of spectrographs for wide bandwidth high resolution spectroscopy and Doppler radial velocimetry. By placing a small angle-independent interferometer near the slit of a spectrograph, periodic fiducials are embedded on the recorded spectrum. The multiplication of the stellar spectrum times the sinusoidal fiducial net creates a moir{acute e} pattern, which manifests high detailed spectral information heterodyned down to detectably low spatial frequencies. The latter can more accurately survive the blurring, distortions and CCD Nyquist limitations of the spectrograph. Hence lower resolution spectrographs can be used to perform high resolution spectroscopy and radial velocimetry. Previous demonstrations of {approx}2.5x resolution boost used an interferometer having a single fixed delay. We report new data indicating {approx}6x Gaussian resolution boost (140,000 from a spectrograph with 25,000 native resolving power), taken by using multiple exposures at widely different interferometer delays.

  16. Risk-adaptive radiotherapy

    NASA Astrophysics Data System (ADS)

    Kim, Yusung

    Currently, there is great interest in integrating biological information into intensity-modulated radiotherapy (IMRT) treatment planning with the aim of boosting high-risk tumor subvolumes. Selective boosting of tumor subvolumes can be accomplished without violating normal tissue complication constraints using information from functional imaging. In this work we have developed a risk-adaptive optimization-framework that utilizes a nonlinear biological objective function. Employing risk-adaptive radiotherapy for prostate cancer, it is possible to increase the equivalent uniform dose (EUD) by up to 35.4 Gy in tumor subvolumes having the highest risk classification without increasing normal tissue complications. Subsequently, we have studied the impact of functional imaging accuracy, and found on the one hand that loss in sensitivity had a large impact on expected local tumor control, which was maximal when a low-risk classification for the remaining low risk PTV was chosen. While on the other hand loss in specificity appeared to have a minimal impact on normal tissue sparing. Therefore, it appears that in order to improve the therapeutic ratio a functional imaging technique with a high sensitivity, rather than specificity, is needed. Last but not least a comparison study between selective boosting IMRT strategies and uniform-boosting IMRT strategies yielding the same EUD to the overall PTV was carried out, and found that selective boosting IMRT considerably improves expected TCP compared to uniform-boosting IMRT, especially when lack of control of the high-risk tumor subvolumes is the cause of expected therapy failure. Furthermore, while selective boosting IMRT, using physical dose-volume objectives, did yield similar rectal and bladder sparing when compared its equivalent uniform-boosting IMRT plan, risk-adaptive radiotherapy, utilizing biological objective functions, did yield a 5.3% reduction in NTCP for the rectum. Hence, in risk-adaptive radiotherapy the

  17. Electric rockets get a boost

    SciTech Connect

    Ashley, S.

    1995-12-01

    This article reports that xenon-ion thrusters are expected to replace conventional chemical rockets in many nonlaunch propulsion tasks, such as controlling satellite orbits and sending space probes on long exploratory missions. The space age dawned some four decades ago with the arrival of powerful chemical rockets that could propel vehicles fast enough to escape the grasp of earth`s gravity. Today, chemical rocket engines still provide the only means to boost payloads into orbit and beyond. The less glamorous but equally important job of moving vessels around in space, however, may soon be assumed by a fundamentally different rocket engine technology that has been long in development--electric propulsion.

  18. Recursive bias estimation and L2 boosting

    SciTech Connect

    Hengartner, Nicolas W; Cornillon, Pierre - Andre; Matzner - Lober, Eric

    2009-01-01

    This paper presents a general iterative bias correction procedure for regression smoothers. This bias reduction schema is shown to correspond operationally to the L{sub 2} Boosting algorithm and provides a new statistical interpretation for L{sub 2} Boosting. We analyze the behavior of the Boosting algorithm applied to common smoothers S which we show depend on the spectrum of I - S. We present examples of common smoother for which Boosting generates a divergent sequence. The statistical interpretation suggest combining algorithm with an appropriate stopping rule for the iterative procedure. Finally we illustrate the practical finite sample performances of the iterative smoother via a simulation study.

  19. Exploiting tRNAs to Boost Virulence.

    PubMed

    Albers, Suki; Czech, Andreas

    2016-01-01

    Transfer RNAs (tRNAs) are powerful small RNA entities that are used to translate nucleotide language of genes into the amino acid language of proteins. Their near-uniform length and tertiary structure as well as their high nucleotide similarity and post-transcriptional modifications have made it difficult to characterize individual species quantitatively. However, due to the central role of the tRNA pool in protein biosynthesis as well as newly emerging roles played by tRNAs, their quantitative assessment yields important information, particularly relevant for virus research. Viruses which depend on the host protein expression machinery have evolved various strategies to optimize tRNA usage-either by adapting to the host codon usage or encoding their own tRNAs. Additionally, several viruses bear tRNA-like elements (TLE) in the 5'- and 3'-UTR of their mRNAs. There are different hypotheses concerning the manner in which such structures boost viral protein expression. Furthermore, retroviruses use special tRNAs for packaging and initiating reverse transcription of their genetic material. Since there is a strong specificity of different viruses towards certain tRNAs, different strategies for recruitment are employed. Interestingly, modifications on tRNAs strongly impact their functionality in viruses. Here, we review those intersection points between virus and tRNA research and describe methods for assessing the tRNA pool in terms of concentration, aminoacylation and modification. PMID:26797637

  20. Exploiting tRNAs to Boost Virulence

    PubMed Central

    Albers, Suki; Czech, Andreas

    2016-01-01

    Transfer RNAs (tRNAs) are powerful small RNA entities that are used to translate nucleotide language of genes into the amino acid language of proteins. Their near-uniform length and tertiary structure as well as their high nucleotide similarity and post-transcriptional modifications have made it difficult to characterize individual species quantitatively. However, due to the central role of the tRNA pool in protein biosynthesis as well as newly emerging roles played by tRNAs, their quantitative assessment yields important information, particularly relevant for virus research. Viruses which depend on the host protein expression machinery have evolved various strategies to optimize tRNA usage—either by adapting to the host codon usage or encoding their own tRNAs. Additionally, several viruses bear tRNA-like elements (TLE) in the 5′- and 3′-UTR of their mRNAs. There are different hypotheses concerning the manner in which such structures boost viral protein expression. Furthermore, retroviruses use special tRNAs for packaging and initiating reverse transcription of their genetic material. Since there is a strong specificity of different viruses towards certain tRNAs, different strategies for recruitment are employed. Interestingly, modifications on tRNAs strongly impact their functionality in viruses. Here, we review those intersection points between virus and tRNA research and describe methods for assessing the tRNA pool in terms of concentration, aminoacylation and modification. PMID:26797637

  1. Series Connected Buck-Boost Regulator

    NASA Technical Reports Server (NTRS)

    Birchenough, Arthur G. (Inventor)

    2006-01-01

    A Series Connected Buck-Boost Regulator (SCBBR) that switches only a fraction of the input power, resulting in relatively high efficiencies. The SCBBR has multiple operating modes including a buck, a boost, and a current limiting mode, so that an output voltage of the SCBBR ranges from below the source voltage to above the source voltage.

  2. Boosting naïve Bayesian learning on a large subset of MEDLINE.

    PubMed Central

    Wilbur, W. J.

    2000-01-01

    We are concerned with the rating of new documents that appear in a large database (MEDLINE) and are candidates for inclusion in a small specialty database (REBASE). The requirement is to rank the new documents as nearly in order of decreasing potential to be added to the smaller database as possible, so as to improve the coverage of the smaller database without increasing the effort of those who manage this specialty database. To perform this ranking task we have considered several machine learning approaches based on the naï ve Bayesian algorithm. We find that adaptive boosting outperforms naï ve Bayes, but that a new form of boosting which we term staged Bayesian retrieval outperforms adaptive boosting. Staged Bayesian retrieval involves two stages of Bayesian retrieval and we further find that if the second stage is replaced by a support vector machine we again obtain a significant improvement over the strictly Bayesian approach. PMID:11080018

  3. Bagging, boosting, and C4.5

    SciTech Connect

    Quinlan, J.R.

    1996-12-31

    Breiman`s bagging and Freund and Schapire`s boosting are recent methods for improving the predictive power of classifier learning systems. Both form a set of classifiers that are combined by voting, bagging by generating replicated bootstrap samples of the data, and boosting by adjusting the weights of training instances. This paper reports results of applying both techniques to a system that learns decision trees and testing on a representative collection of datasets. While both approaches substantially improve predictive accuracy, boosting shows the greater benefit. On the other hand, boosting also produces severe degradation on some datasets. A small change to the way that boosting combines the votes of learned classifiers reduces this downside and also leads to slightly better results on most of the datasets considered.

  4. Boosting human learning by hypnosis.

    PubMed

    Nemeth, Dezso; Janacsek, Karolina; Polner, Bertalan; Kovacs, Zoltan Ambrus

    2013-04-01

    Human learning and memory depend on multiple cognitive systems related to dissociable brain structures. These systems interact not only in cooperative but also sometimes competitive ways in optimizing performance. Previous studies showed that manipulations reducing the engagement of frontal lobe-mediated explicit attentional processes could lead to improved performance in striatum-related procedural learning. In our study, hypnosis was used as a tool to reduce the competition between these 2 systems. We compared learning in hypnosis and in the alert state and found that hypnosis boosted striatum-dependent sequence learning. Since frontal lobe-dependent processes are primarily affected by hypnosis, this finding could be attributed to the disruption of the explicit attentional processes. Our result sheds light not only on the competitive nature of brain systems in cognitive processes but also could have important implications for training and rehabilitation programs, especially for developing new methods to improve human learning and memory performance.

  5. Advanced Airfoils Boost Helicopter Performance

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Carson Helicopters Inc. licensed the Langley RC4 series of airfoils in 1993 to develop a replacement main rotor blade for their Sikorsky S-61 helicopters. The company's fleet of S-61 helicopters has been rebuilt to include Langley's patented airfoil design, and the helicopters are now able to carry heavier loads and fly faster and farther, and the main rotor blades have twice the previous service life. In aerial firefighting, the performance-boosting airfoils have helped the U.S. Department of Agriculture's Forest Service control the spread of wildfires. In 2003, Carson Helicopters signed a contract with Ducommun AeroStructures Inc., to manufacture the composite blades for Carson Helicopters to sell

  6. Boost-phase discrimination research

    NASA Technical Reports Server (NTRS)

    Langhoff, Stephen R.; Feiereisen, William J.

    1993-01-01

    The final report describes the combined work of the Computational Chemistry and Aerothermodynamics branches within the Thermosciences Division at NASA Ames Research Center directed at understanding the signatures of shock-heated air. Considerable progress was made in determining accurate transition probabilities for the important band systems of NO that account for much of the emission in the ultraviolet region. Research carried out under this project showed that in order to reproduce the observed radiation from the bow shock region of missiles in their boost phase it is necessary to include the Burnett terms in the constituent equation, account for the non-Boltzmann energy distribution, correctly model the NO formation and rotational excitation process, and use accurate transition probabilities for the NO band systems. This work resulted in significant improvements in the computer code NEQAIR that models both the radiation and fluid dynamics in the shock region.

  7. Riemann curvature of a boosted spacetime geometry

    NASA Astrophysics Data System (ADS)

    Battista, Emmanuele; Esposito, Giampiero; Scudellaro, Paolo; Tramontano, Francesco

    2016-10-01

    The ultrarelativistic boosting procedure had been applied in the literature to map the metric of Schwarzschild-de Sitter spacetime into a metric describing de Sitter spacetime plus a shock-wave singularity located on a null hypersurface. This paper evaluates the Riemann curvature tensor of the boosted Schwarzschild-de Sitter metric by means of numerical calculations, which make it possible to reach the ultrarelativistic regime gradually by letting the boost velocity approach the speed of light. Thus, for the first time in the literature, the singular limit of curvature, through Dirac’s δ distribution and its derivatives, is numerically evaluated for this class of spacetimes. Moreover, the analysis of the Kretschmann invariant and the geodesic equation shows that the spacetime possesses a “scalar curvature singularity” within a 3-sphere and it is possible to define what we here call “boosted horizon”, a sort of elastic wall where all particles are surprisingly pushed away, as numerical analysis demonstrates. This seems to suggest that such “boosted geometries” are ruled by a sort of “antigravity effect” since all geodesics seem to refuse to enter the “boosted horizon” and are “reflected” by it, even though their initial conditions are aimed at driving the particles toward the “boosted horizon” itself. Eventually, the equivalence with the coordinate shift method is invoked in order to demonstrate that all δ2 terms appearing in the Riemann curvature tensor give vanishing contribution in distributional sense.

  8. Boosting domain wall propagation by notches

    NASA Astrophysics Data System (ADS)

    Yuan, H. Y.; Wang, X. R.

    2015-08-01

    We report a counterintuitive finding that notches in an otherwise homogeneous magnetic nanowire can boost current-induced domain wall (DW) propagation. DW motion in notch-modulated wires can be classified into three phases: (1) A DW is pinned around a notch when the current density is below the depinning current density. (2) DW propagation velocity is boosted by notches above the depinning current density and when nonadiabatic spin-transfer torque strength β is smaller than the Gilbert damping constant α . The boost can be multifold. (3) DW propagation velocity is hindered when β >α . The results are explained by using the Thiele equation.

  9. Skip Dinner and Maybe Boost Your Metabolism

    MedlinePlus

    ... 161845.html Skip Dinner and Maybe Boost Your Metabolism But, study didn't show overall changes in ... has an internal clock, and many aspects of metabolism are working best in the morning, according to ...

  10. Old Drug Boosts Brain's Memory Centers

    MedlinePlus

    ... gov/news/fullstory_159605.html Old Drug Boosts Brain's Memory Centers But more research needed before recommending ... called methylene blue may rev up activity in brain regions involved in short-term memory and attention, ...

  11. Avoiding Anemia: Boost Your Red Blood Cells

    MedlinePlus

    ... link, please review our exit disclaimer . Subscribe Avoiding Anemia Boost Your Red Blood Cells If you’re ... and sluggish, you might have a condition called anemia. Anemia is a common blood disorder that many ...

  12. Tools to Boost Steam System Efficiency

    SciTech Connect

    2005-05-01

    The Steam System Scoping Tool quickly evaluates your entire steam system operation and spots the areas that are the best opportunities for improvement. The tool suggests a range of ways to save steam energy and boost productivity.

  13. Relativistic projection and boost of solitons

    SciTech Connect

    Wilets, L.

    1991-01-01

    This report discusses the following topics on the relativistic projection and boost of solitons: The center of mass problem; momentum eigenstates; variation after projection; and the nucleon as a composite. (LSP).

  14. Relativistic projection and boost of solitons

    SciTech Connect

    Wilets, L.

    1991-12-31

    This report discusses the following topics on the relativistic projection and boost of solitons: The center of mass problem; momentum eigenstates; variation after projection; and the nucleon as a composite. (LSP).

  15. Anemia Boosts Stroke Death Risk, Study Finds

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_160476.html Anemia Boosts Stroke Death Risk, Study Finds Blood condition ... 2016 (HealthDay News) -- Older stroke victims suffering from anemia -- a lack of red blood cells -- may have ...

  16. Centaur liquid oxygen boost pump vibration test

    NASA Technical Reports Server (NTRS)

    Tang, H. M.

    1975-01-01

    The Centaur LOX boost pump was subjected to both the simulated Titan Centaur proof flight and confidence demonstration vibration test levels. For each test level, both sinusoidal and random vibration tests were conducted along each of the three orthogonal axes of the pump and turbine assembly. In addition to these tests, low frequency longitudinal vibration tests for both levels were conducted. All tests were successfully completed without damage to the boost pump.

  17. Buckley-James Boosting for Survival Analysis with High-Dimensional Biomarker Data*

    PubMed Central

    Wang, Zhu; Wang, C.Y.

    2010-01-01

    There has been increasing interest in predicting patients’ survival after therapy by investigating gene expression microarray data. In the regression and classification models with high-dimensional genomic data, boosting has been successfully applied to build accurate predictive models and conduct variable selection simultaneously. We propose the Buckley-James boosting for the semiparametric accelerated failure time models with right censored survival data, which can be used to predict survival of future patients using the high-dimensional genomic data. In the spirit of adaptive LASSO, twin boosting is also incorporated to fit more sparse models. The proposed methods have a unified approach to fit linear models, non-linear effects models with possible interactions. The methods can perform variable selection and parameter estimation simultaneously. The proposed methods are evaluated by simulations and applied to a recent microarray gene expression data set for patients with diffuse large B-cell lymphoma under the current gold standard therapy. PMID:20597850

  18. FULL ELECTROMAGNETIC FEL SIMULATION VIA THE LORENTZ-BOOSTED FRAME TRANSFORMATION

    SciTech Connect

    Fawley, William; Vay, Jean-Luc

    2010-08-16

    Numerical electromagnetic simulation of some systems containing charged particles with highly relativistic directed motion can by speeded up by orders of magnitude by choice of the proper Lorentz-boosted frame. A particularly good application for calculation in a boosted frame isthat of short wavelength free-electron lasers (FELs) where a high energy electron beam with small fractional energy spread interacts with a static magnetic undulator. In the optimal boost frame (i.e., the ponderomotive rest frame), the red-shifted FEL radiation and blue-shifted undulator field have identical wavelengths and the number of required longitudinal grid cells and time-steps for fully electromagnetic simulation (relative to the laboratory frame) decrease by factors of gamma^2 each. In theory, boosted frame EM codes permit direct study of FEL problems for which the eikonal approximation for propagation of the radiation field and wiggler-period-averaging for the particle-field interaction may be suspect. We have adapted the WARP code to apply this method to several electromagnetic FEL problems including spontaneous emission, strong exponential gain in a seeded, single pass amplifier configuration, and emission from e-beams in undulators with multiple harmonic components. WARP has a standard relativistic macroparticle mover and a fully 3-D electromagnetic field solver. We discuss our boosted frame results and compare with those obtained using the ?standard? eikonal FEL simulation approach.

  19. Tracking down hyper-boosted top quarks

    SciTech Connect

    Larkoski, Andrew J.; Maltoni, Fabio; Selvaggi, Michele

    2015-06-05

    The identification of hadronically decaying heavy states, such as vector bosons, the Higgs, or the top quark, produced with large transverse boosts has been and will continue to be a central focus of the jet physics program at the Large Hadron Collider (LHC). At a future hadron collider working at an order-of-magnitude larger energy than the LHC, these heavy states would be easily produced with transverse boosts of several TeV. At these energies, their decay products will be separated by angular scales comparable to individual calorimeter cells, making the current jet substructure identification techniques for hadronic decay modes not directly employable. In addition, at the high energy and luminosity projected at a future hadron collider, there will be numerous sources for contamination including initial- and final-state radiation, underlying event, or pile-up which must be mitigated. We propose a simple strategy to tag such "hyper-boosted" objects that defines jets with radii that scale inversely proportional to their transverse boost and combines the standard calorimetric information with charged track-based observables. By means of a fast detector simulation, we apply it to top quark identification and demonstrate that our method efficiently discriminates hadronically decaying top quarks from light QCD jets up to transverse boosts of 20 TeV. Lastly, our results open the way to tagging heavy objects with energies in the multi-TeV range at present and future hadron colliders.

  20. Tracking down hyper-boosted top quarks

    DOE PAGES

    Larkoski, Andrew J.; Maltoni, Fabio; Selvaggi, Michele

    2015-06-05

    The identification of hadronically decaying heavy states, such as vector bosons, the Higgs, or the top quark, produced with large transverse boosts has been and will continue to be a central focus of the jet physics program at the Large Hadron Collider (LHC). At a future hadron collider working at an order-of-magnitude larger energy than the LHC, these heavy states would be easily produced with transverse boosts of several TeV. At these energies, their decay products will be separated by angular scales comparable to individual calorimeter cells, making the current jet substructure identification techniques for hadronic decay modes not directlymore » employable. In addition, at the high energy and luminosity projected at a future hadron collider, there will be numerous sources for contamination including initial- and final-state radiation, underlying event, or pile-up which must be mitigated. We propose a simple strategy to tag such "hyper-boosted" objects that defines jets with radii that scale inversely proportional to their transverse boost and combines the standard calorimetric information with charged track-based observables. By means of a fast detector simulation, we apply it to top quark identification and demonstrate that our method efficiently discriminates hadronically decaying top quarks from light QCD jets up to transverse boosts of 20 TeV. Lastly, our results open the way to tagging heavy objects with energies in the multi-TeV range at present and future hadron colliders.« less

  1. Tracking down hyper-boosted top quarks

    NASA Astrophysics Data System (ADS)

    Larkoski, Andrew J.; Maltoni, Fabio; Selvaggi, Michele

    2015-06-01

    The identification of hadronically decaying heavy states, such as vector bosons, the Higgs, or the top quark, produced with large transverse boosts has been and will continue to be a central focus of the jet physics program at the Large Hadron Collider (LHC). At a future hadron collider working at an order-of-magnitude larger energy than the LHC, these heavy states would be easily produced with transverse boosts of several TeV. At these energies, their decay products will be separated by angular scales comparable to individual calorimeter cells, making the current jet substructure identification techniques for hadronic decay modes not directly employable. In addition, at the high energy and luminosity projected at a future hadron collider, there will be numerous sources for contamination including initial- and final-state radiation, underlying event, or pile-up which must be mitigated. We propose a simple strategy to tag such "hyper-boosted" objects that defines jets with radii that scale inversely proportional to their transverse boost and combines the standard calorimetric information with charged track-based observables. By means of a fast detector simulation, we apply it to top quark identification and demonstrate that our method efficiently discriminates hadronically decaying top quarks from light QCD jets up to transverse boosts of 20 TeV. Our results open the way to tagging heavy objects with energies in the multi-TeV range at present and future hadron colliders.

  2. Centrifugal compressor design for electrically assisted boost

    NASA Astrophysics Data System (ADS)

    Y Yang, M.; Martinez-Botas, R. F.; Zhuge, W. L.; Qureshi, U.; Richards, B.

    2013-12-01

    Electrically assisted boost is a prominent method to solve the issues of transient lag in turbocharger and remains an optimized operation condition for a compressor due to decoupling from turbine. Usually a centrifugal compressor for gasoline engine boosting is operated at high rotational speed which is beyond the ability of an electric motor in market. In this paper a centrifugal compressor with rotational speed as 120k RPM and pressure ratio as 2.0 is specially developed for electrically assisted boost. A centrifugal compressor including the impeller, vaneless diffuser and the volute is designed by meanline method followed by 3D detailed design. Then CFD method is employed to predict as well as analyse the performance of the design compressor. The results show that the pressure ratio and efficiency at design point is 2.07 and 78% specifically.

  3. The Attentional Boost Effect and Context Memory

    ERIC Educational Resources Information Center

    Mulligan, Neil W.; Smith, S. Adam; Spataro, Pietro

    2016-01-01

    Stimuli co-occurring with targets in a detection task are better remembered than stimuli co-occurring with distractors--the attentional boost effect (ABE). The ABE is of interest because it is an exception to the usual finding that divided attention during encoding impairs memory. The effect has been demonstrated in tests of item memory but it is…

  4. Schools Enlisting Defense Industry to Boost STEM

    ERIC Educational Resources Information Center

    Trotter, Andrew

    2008-01-01

    Defense contractors Northrop Grumman Corp. and Lockheed Martin Corp. are joining forces in an innovative partnership to develop high-tech simulations to boost STEM--or science, technology, engineering, and mathematics--education in the Baltimore County schools. The Baltimore County partnership includes the local operations of two major military…

  5. Cleanouts boost Devonian shale gas flow

    SciTech Connect

    Not Available

    1991-02-04

    Cleaning shale debris from the well bores is an effective way to boost flow rates from old open hole Devonian shale gas wells, research on six West Virginia wells begun in 1985 has shown. Officials involved with the study say the Appalachian basin could see 20 year recoverable gas reserves hiked by 315 bcf if the process is used on a wide scale.

  6. Discussion of "the evolution of boosting algorithms" and "extending statistical boosting".

    PubMed

    Bühlmann, P; Gertheiss, J; Hieke, S; Kneib, T; Ma, S; Schumacher, M; Tutz, G; Wang, C-Y; Wang, Z; Ziegler, A

    2014-01-01

    This article is part of a For-Discussion-Section of Methods of Information in Medicine about the papers "The Evolution of Boosting Algorithms - From Machine Learning to Statistical Modelling" and "Extending Statistical Boosting - An Overview of Recent Methodological Developments", written by Andreas Mayr and co-authors. It is introduced by an editorial. This article contains the combined commentaries invited to independently comment on the Mayr et al. papers. In subsequent issues the discussion can continue through letters to the editor.

  7. Effect of TRMM boost on oceanic rain rate estimates based on microwave brightness temperature histograms

    NASA Astrophysics Data System (ADS)

    Chiu, L. S.; Shin, D.; Chokngamwong, R.

    2006-05-01

    A statistical emission-based passive microwave retrieval algorithm developed by Wilheit, Chang and Chiu (1991) has been used to estimate space/time oceanic rainfall. The algorithm has been applied to Special Sensor Microwave Imager (SSM/I) data taken on board the Defense Meteorological Satellite Program (DMSP) satellites to provide monthly oceanic rainfall over 2.5ºx2.5º and 5ºx5º latitude-longitude boxes by the Global Precipitation Climatology Project-Polar Satellite Precipitation Data Center (GPCP-PSPDC, URL: http://gpcp- pspdc.gmu.edu) as part of NASA's contribution to the GPCP. The algorithm has been adapted to the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) data to produce a TRMM Level 3 standard product (3A11) over 5ºx5º latitude/longitude boxes. To extend the TRMM mission, the TRMM satellite was boosted to a higher altitude thus changing the rain rate-brightness temperature relation and other rain rate parameters in the estimation procedure. Comparison with the SSM/I product showed a statistically significant difference between the pre and post boost TMI monthly rain rates. Our results showed that the difference can be reconciled in terms of the changes in earth's incidence angle of TMI, the freezing level height, and the beam-filling correction factor. After the incorporation of these changes for the post boost data, there is no significant difference between the pre and post-boost 3A11 data.

  8. Boosting Big National Lab Data

    SciTech Connect

    Kleese van Dam, Kerstin

    2013-02-21

    Introduction: Big data. Love it or hate it, solving the world’s most intractable problems requires the ability to make sense of huge and complex sets of data and do it quickly. Speeding up the process – from hours to minutes or from weeks to days – is key to our success. One major source of such big data are physical experiments. As many will know, these physical experiments are commonly used to solve challenges in fields such as energy security, manufacturing, medicine, pharmacology, environmental protection and national security. Experiments use different instruments and sensor types to research for example the validity of new drugs, the base cause for diseases, more efficient energy sources, new materials for every day goods, effective methods for environmental cleanup, the optimal ingredients composition for chocolate or determine how to preserve valuable antics. This is done by experimentally determining the structure, properties and processes that govern biological systems, chemical processes and materials. The speed and quality at which we can acquire new insights from experiments directly influences the rate of scientific progress, industrial innovation and competitiveness. And gaining new groundbreaking insights, faster, is key to the economic success of our nations. Recent years have seen incredible advances in sensor technologies, from house size detector systems in large experiments such as the Large Hadron Collider and the ‘Eye of Gaia’ billion pixel camera detector to high throughput genome sequencing. These developments have led to an exponential increase in data volumes, rates and variety produced by instruments used for experimental work. This increase is coinciding with a need to analyze the experimental results at the time they are collected. This speed is required to optimize the data taking and quality, and also to enable new adaptive experiments, where the sample is manipulated as it is observed, e.g. a substance is injected into a

  9. Bioactive Molecule Prediction Using Extreme Gradient Boosting.

    PubMed

    Babajide Mustapha, Ismail; Saeed, Faisal

    2016-01-01

    Following the explosive growth in chemical and biological data, the shift from traditional methods of drug discovery to computer-aided means has made data mining and machine learning methods integral parts of today's drug discovery process. In this paper, extreme gradient boosting (Xgboost), which is an ensemble of Classification and Regression Tree (CART) and a variant of the Gradient Boosting Machine, was investigated for the prediction of biological activity based on quantitative description of the compound's molecular structure. Seven datasets, well known in the literature were used in this paper and experimental results show that Xgboost can outperform machine learning algorithms like Random Forest (RF), Support Vector Machines (LSVM), Radial Basis Function Neural Network (RBFN) and Naïve Bayes (NB) for the prediction of biological activities. In addition to its ability to detect minority activity classes in highly imbalanced datasets, it showed remarkable performance on both high and low diversity datasets. PMID:27483216

  10. Voltage-Boosting Driver For Switching Regulator

    NASA Technical Reports Server (NTRS)

    Trump, Ronald C.

    1990-01-01

    Driver circuit assures availability of 10- to 15-V gate-to-source voltage needed to turn on n-channel metal oxide/semiconductor field-effect transistor (MOSFET) acting as switch in switching voltage regulator. Includes voltage-boosting circuit efficiently providing gate voltage 10 to 15 V above supply voltage. Contains no exotic parts and does not require additional power supply. Consists of NAND gate and dual voltage booster operating in conjunction with pulse-width modulator part of regulator.

  11. Image enhancement based on edge boosting algorithm

    NASA Astrophysics Data System (ADS)

    Ngernplubpla, Jaturon; Chitsobhuk, Orachat

    2015-12-01

    In this paper, a technique for image enhancement based on proposed edge boosting algorithm to reconstruct high quality image from a single low resolution image is described. The difficulty in single-image super-resolution is that the generic image priors resided in the low resolution input image may not be sufficient to generate the effective solutions. In order to achieve a success in super-resolution reconstruction, efficient prior knowledge should be estimated. The statistics of gradient priors in terms of priority map based on separable gradient estimation, maximum likelihood edge estimation, and local variance are introduced. The proposed edge boosting algorithm takes advantages of these gradient statistics to select the appropriate enhancement weights. The larger weights are applied to the higher frequency details while the low frequency details are smoothed. From the experimental results, the significant performance improvement quantitatively and perceptually is illustrated. It can be seen that the proposed edge boosting algorithm demonstrates high quality results with fewer artifacts, sharper edges, superior texture areas, and finer detail with low noise.

  12. Exposure fusion using boosting Laplacian pyramid.

    PubMed

    Shen, Jianbing; Zhao, Ying; Yan, Shuicheng; Li, Xuelong

    2014-09-01

    This paper proposes a new exposure fusion approach for producing a high quality image result from multiple exposure images. Based on the local weight and global weight by considering the exposure quality measurement between different exposure images, and the just noticeable distortion-based saliency weight, a novel hybrid exposure weight measurement is developed. This new hybrid weight is guided not only by a single image's exposure level but also by the relative exposure level between different exposure images. The core of the approach is our novel boosting Laplacian pyramid, which is based on the structure of boosting the detail and base signal, respectively, and the boosting process is guided by the proposed exposure weight. Our approach can effectively blend the multiple exposure images for static scenes while preserving both color appearance and texture structure. Our experimental results demonstrate that the proposed approach successfully produces visually pleasing exposure fusion images with better color appearance and more texture details than the existing exposure fusion techniques and tone mapping operators. PMID:25137687

  13. Attention modulates visual size adaptation.

    PubMed

    Kreutzer, Sylvia; Fink, Gereon R; Weidner, Ralph

    2015-01-01

    The current study determined in healthy subjects (n = 16) whether size adaptation occurs at early, i.e., preattentive, levels of processing or whether higher cognitive processes such as attention can modulate the illusion. To investigate this issue, bottom-up stimulation was kept constant across conditions by using a single adaptation display containing both small and large adapter stimuli. Subjects' attention was directed to either the large or small adapter stimulus by means of a luminance detection task. When attention was directed toward the small as compared to the large adapter, the perceived size of the subsequent target was significantly increased. Data suggest that different size adaptation effects can be induced by one and the same stimulus depending on the current allocation of attention. This indicates that size adaptation is subject to attentional modulation. These findings are in line with previous research showing that transient as well as sustained attention modulates visual features, such as contrast sensitivity and spatial frequency, and influences adaptation in other contexts, such as motion adaptation (Alais & Blake, 1999; Lankheet & Verstraten, 1995). Based on a recently suggested model (Pooresmaeili, Arrighi, Biagi, & Morrone, 2013), according to which perceptual adaptation is based on local excitation and inhibition in V1, we conclude that guiding attention can boost these local processes in one or the other direction by increasing the weight of the attended adapter. In sum, perceptual adaptation, although reflected in changes of neural activity at early levels (as shown in the aforementioned study), is nevertheless subject to higher-order modulation.

  14. Hybrid Recovery-less Method Soft Switching Boost Chopper Circuit

    NASA Astrophysics Data System (ADS)

    Yamamoto, Masayoshi; Toda, Hirotaka; Kawashima, Takahiro; Yoshida, Toshiyuki

    The conventional recovery-less boost type converter cannot achieve the soft switching operation in case of the turn off transition. In this paper, the novel hybrid recovery-less boost type converter, which can achieve the soft switching turn off transition, is proposed. Furthermore, the proposed hybrid recovery-less boost type converter has the switch function between the conventional recovery-less mode and the proposed soft switching mode. In general, the efficiency in the soft switching converter is less than the hard switching in case of the lower output power condition. However, using the switch function of the proposed boost type converter, the hybrid recovery-less boost type converter can achieve the high efficiency performance in the whole output power area in spite of the soft switching operation. The proposed hybrid recovery-less boost type converter is evaluated and discussed from experimental point of view.

  15. Boost matrix converters in clean energy systems

    NASA Astrophysics Data System (ADS)

    Karaman, Ekrem

    This dissertation describes an investigation of novel power electronic converters, based on the ultra-sparse matrix topology and characterized by the minimum number of semiconductor switches. The Z-source, Quasi Z-source, Series Z-source and Switched-inductor Z-source networks were originally proposed for boosting the output voltage of power electronic inverters. These ideas were extended here on three-phase to three-phase and three-phase to single-phase indirect matrix converters. For the three-phase to three-phase matrix converters, the Z-source networks are placed between the three-switch input rectifier stage and the output six-switch inverter stage. A brief shoot-through state produces the voltage boost. An optimal pulse width modulation technique was developed to achieve high boosting capability and minimum switching losses in the converter. For the three-phase to single-phase matrix converters, those networks are placed similarly. For control purposes, a new modulation technique has been developed. As an example application, the proposed converters constitute a viable alternative to the existing solutions in residential wind-energy systems, where a low-voltage variable-speed generator feeds power to the higher-voltage fixed-frequency grid. Comprehensive analytical derivations and simulation results were carried out to investigate the operation of the proposed converters. Performance of the proposed converters was then compared between each other as well as with conventional converters. The operation of the converters was experimentally validated using a laboratory prototype.

  16. Boosting family income to promote child development.

    PubMed

    Duncan, Greg J; Magnuson, Katherine; Votruba-Drzal, Elizabeth

    2014-01-01

    Families who live in poverty face disadvantages that can hinder their children's development in many ways, write Greg Duncan, Katherine Magnuson, and Elizabeth Votruba-Drzal. As they struggle to get by economically, and as they cope with substandard housing, unsafe neighborhoods, and inadequate schools, poor families experience more stress in their daily lives than more affluent families do, with a host of psychological and developmental consequences. Poor families also lack the resources to invest in things like high-quality child care and enriched learning experiences that give more affluent children a leg up. Often, poor parents also lack the time that wealthier parents have to invest in their children, because poor parents are more likely to be raising children alone or to work nonstandard hours and have inflexible work schedules. Can increasing poor parents' incomes, independent of any other sort of assistance, help their children succeed in school and in life? The theoretical case is strong, and Duncan, Magnuson, and Votruba-Drzal find solid evidence that the answer is yes--children from poor families that see a boost in income do better in school and complete more years of schooling, for example. But if boosting poor parents' incomes can help their children, a crucial question remains: Does it matter when in a child's life the additional income appears? Developmental neurobiology strongly suggests that increased income should have the greatest effect during children's early years, when their brains and other systems are developing rapidly, though we need more evidence to prove this conclusively. The authors offer examples of how policy makers could incorporate the findings they present to create more effective programs for families living in poverty. And they conclude with a warning: if a boost in income can help poor children, then a drop in income--for example, through cuts to social safety net programs like food stamps--can surely harm them.

  17. Boosting salt resistance of short antimicrobial peptides.

    PubMed

    Chu, Hung-Lun; Yu, Hui-Yuan; Yip, Bak-Sau; Chih, Ya-Han; Liang, Chong-Wen; Cheng, Hsi-Tsung; Cheng, Jya-Wei

    2013-08-01

    The efficacies of many antimicrobial peptides are greatly reduced under high salt concentrations, therefore limiting their use as pharmaceutical agents. Here, we describe a strategy to boost salt resistance and serum stability of short antimicrobial peptides by adding the nonnatural bulky amino acid β-naphthylalanine to their termini. The activities of the short salt-sensitive tryptophan-rich peptide S1 were diminished at high salt concentrations, whereas the activities of its β-naphthylalanine end-tagged variants were less affected.

  18. Boost covariant gluon distributions in large nuclei

    NASA Astrophysics Data System (ADS)

    McLerran, Larry; Venugopalan, Raju

    1998-04-01

    It has been shown recently that there exist analytical solutions of the Yang-Mills equations for non-Abelian Weizsäcker-Williams fields which describe the distribution of gluons in large nuclei at small x. These solutions however depend on the color charge distribution at large rapidities. We here construct a model of the color charge distribution of partons in the fragmentation region and use it to compute the boost covariant momentum distributions of wee gluons. The phenomenological applications of our results are discussed.

  19. Low temperature operation of a boost converter

    SciTech Connect

    Moss, B.S.; Boudreaux, R.R.; Nelms, R.M.

    1996-12-31

    The development of satellite power systems capable of operating at low temperatures on the order of 77K would reduce the heating system required on deep space vehicles. The power supplies in the satellite power system must be capable of operating at these temperatures. This paper presents the results of a study into the operation of a boost converter at temperatures close to 77K. The boost converter is designed to supply an output voltage and power of 42 V and 50 W from a 28 V input source. The entire system, except the 28 V source, is placed in the environmental chamber. This is important because the system does not require any manual adjustments to maintain a constant output voltage with a high efficiency. The constant 42 V output of this converter is a benefit of the application of a CMOS microcontroller in the feedback path. The switch duty cycle is adjusted by the microcontroller to maintain a constant output voltage. The efficiency of the system varied less than 1% over the temperature range of 22 C to {minus}184 C and was approximately 94.2% when the temperature was {minus}184 C.

  20. Jet substructures of boosted polarized top quarks

    NASA Astrophysics Data System (ADS)

    Kitadono, Yoshio; Li, Hsiang-nan

    2014-06-01

    We study jet substructures of a boosted polarized top quark, which undergoes the semileptonic decay t→bℓν, in the perturbative QCD framework. The jet mass distribution (energy profile) is factorized into the convolution of a hard top-quark decay kernel with the bottom-quark jet function (jet energy function). Computing the hard kernel to the leading order in QCD and inputting the latter functions from the resummation formalism, we observe that the jet mass distribution is not sensitive to the helicity of the top quark, but the energy profile is: energy is accumulated faster within a left-hand top jet than within a right-hand one, a feature related to the V-A structure of weak interaction. It is pointed out that the energy profile is a simple and useful jet observable for helicity discrimination of a boosted top quark, which helps identification of physics beyond the standard model at the Large Hadron Collider. The extension of our analysis to other jet substructures, including those associated with a hadronically decaying polarized top quark, is proposed.

  1. Brain glucosamine boosts protective glucoprivic feeding.

    PubMed

    Osundiji, Mayowa A; Zhou, Ligang; Shaw, Jill; Moore, Stephen P; Yueh, Chen-Yu; Sherwin, Robert; Heisler, Lora K; Evans, Mark L

    2010-04-01

    The risk of iatrogenic hypoglycemia is increased in diabetic patients who lose defensive glucoregulatory responses, including the important warning symptom of hunger. Protective hunger symptoms during hypoglycemia may be triggered by hypothalamic glucose-sensing neurons by monitoring changes downstream of glucose phosphorylation by the specialized glucose-sensing hexokinase, glucokinase (GK), during metabolism. Here we investigated the effects of intracerebroventricular (ICV) infusion of glucosamine (GSN), a GK inhibitor, on food intake at normoglycemia and protective feeding responses during glucoprivation and hypoglycemia in chronically catheterized rats. ICV infusion of either GSN or mannoheptulose, a structurally different GK inhibitor, dose-dependently stimulated feeding at normoglycemia. Consistent with an effect of GSN to inhibit competitively glucose metabolism, ICV coinfusion of d-glucose but not l-glucose abrogated the orexigenic effect of ICV GSN at normoglycemia. Importantly, ICV infusion of a low GSN dose (15 nmol/min) that was nonorexigenic at normoglycemia boosted feeding responses to glucoprivation in rats with impaired glucose counterregulation. ICV infusion of 15 nmol/min GSN also boosted feeding responses to threatened hypoglycemia in rats with defective glucose counterregulation. Altogether our findings suggest that GSN may be a potential therapeutic candidate for enhancing defensive hunger symptoms during hypoglycemia.

  2. Boost in radiotherapy: external beam sunset, brachytherapy sunrise

    PubMed Central

    2009-01-01

    Radiobiological limitations for dose escalation in external radiotherapy are presented. Biological and clinical concept of brachytherapy boost to increase treatment efficacy is discussed, and different methods are compared. Oncentra Prostate 3D conformal real-time ultrasound-guided brachytherapy is presented as a solution for boost or sole therapy.

  3. FULL ELECTROMAGNETIC SIMULATION OF COHERENT SYNCHROTRON RADIATION VIA THE LORENTZ-BOOSTED FRAME APPROACH

    SciTech Connect

    Fawley, William M; Vay, Jean-Luc

    2010-05-21

    Numerical simulation of some systems containing charged particles with highly relativistic directed motion can by speeded up by orders of magnitude by choice of the proper Lorentz-boosted frame. Orders of magnitude speedup has been demonstrated for simulations from first principles of laser-plasma accelerator, free electron laser, and particle beams interacting with electron clouds. Here we address the application of the Lorentz-boosted frame approach to coherent synchrotron radiation (CSR), which can be strongly present in bunch compressor chicanes. CSR is particularly relevant to the next generation of x-ray light sources and is simultaneously difficult to simulate in the lab frame because of the large ratio of scale lengths. It can increase both the incoherent and coherent longitudinal energy spread, effects that often lead to an increase in transverse emittance. We have adapted the WARP code to simulate CSR emission along a simple dipole bend. We present some scaling arguments for the possible computational speed up factor in the boosted frame and initial 3D simulation results.

  4. Novel Control for Voltage Boosted Matrix Converter based Wind Energy Conversion System with Practicality

    NASA Astrophysics Data System (ADS)

    Kumar, Vinod; Joshi, Raghuveer Raj; Yadav, Dinesh Kumar; Garg, Rahul Kumar

    2016-06-01

    This paper presents the implementation and investigation of novel voltage boosted matrix converter (MC) based permanent magnet wind energy conversion system (WECS). In this paper, on-line tuned adaptive fuzzy control algorithm cooperated with reversed MC is proposed to yield maximum energy. The control system is implemented on a dSPACE DS1104 real time board. Feasibility of the proposed system has been experimentally verified using a laboratory 1.2 kW prototype of WECS under steady-state and dynamic conditions.

  5. Ascent Guidance for a Winged Boost Vehicle. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Corvin, Michael Alexander

    1988-01-01

    The objective of the advanced ascent guidance study was to investigate guidance concepts which could contribute to increased autonomy during ascent operations in a winged boost vehicle such as the proposed Shuttle II. The guidance scheme was required to yield near a full-optimal ascent in the presence of vehicle system and environmental dispersions. The study included consideration of trajectory shaping issues, trajectory design, closed loop and predictive adaptive guidance techniques and control of dynamic pressure by throttling. An extensive ascent vehicle simulation capability was developed for use in the study.

  6. Dynamics of multirate sampled data control systems. [for space shuttle boost vehicle

    NASA Technical Reports Server (NTRS)

    Naylor, J. R.; Hynes, R. J.; Molnar, D. O.

    1974-01-01

    The effect was investigated of the synthesis approach (single or multirate) on the machine requirements for a digital control system for the space shuttle boost vehicle. The study encompassed four major work areas: synthesis approach trades, machine requirements trades, design analysis requirements and multirate adaptive control techniques. The primary results are two multirate autopilot designs for the low Q and maximum Q flight conditions that exhibits equal or better performance than the analog and single rate system designs. Also, a preferred technique for analyzing and synthesizing multirate digital control systems is included.

  7. Boosting jet power in black hole spacetimes

    PubMed Central

    Neilsen, David; Lehner, Luis; Palenzuela, Carlos; Hirschmann, Eric W.; Liebling, Steven L.; Motl, Patrick M.; Garrett, Travis

    2011-01-01

    The extraction of rotational energy from a spinning black hole via the Blandford–Znajek mechanism has long been understood as an important component in models to explain energetic jets from compact astrophysical sources. Here we show more generally that the kinetic energy of the black hole, both rotational and translational, can be tapped, thereby producing even more luminous jets powered by the interaction of the black hole with its surrounding plasma. We study the resulting Poynting jet that arises from single boosted black holes and binary black hole systems. In the latter case, we find that increasing the orbital angular momenta of the system and/or the spins of the individual black holes results in an enhanced Poynting flux. PMID:21768341

  8. Hydrodynamic approach to boost invariant free streaming

    NASA Astrophysics Data System (ADS)

    Calzetta, E.

    2015-08-01

    We consider a family of exact boost invariant solutions of the transport equation for free-streaming massless particles, where the one-particle distribution function is defined in terms of a function of a single variable. The evolution of second and third moments of the one-particle distribution function [the second moment being the energy momentum tensor (EMT) and the third moment the nonequilibrium current (NEC)] depends only on two moments of that function. Given those two moments, we show how to build a nonlinear hydrodynamic theory which reproduces the early time evolution of the EMT and the NEC. The structure of these theories may give insight on nonlinear hydrodynamic phenomena on short time scales.

  9. Boosting low-mass hadronic resonances

    NASA Astrophysics Data System (ADS)

    Shimmin, Chase; Whiteson, Daniel

    2016-09-01

    Searches for new hadronic resonances typically focus on high-mass spectra due to overwhelming QCD backgrounds and detector trigger rates. We present a study of searches for relatively low-mass hadronic resonances at the LHC in the case that the resonance is boosted by recoiling against a well-measured high-pT probe such as a muon, photon or jet. The hadronic decay of the resonance is then reconstructed either as a single large-radius jet or as a resolved pair of standard narrow-radius jets, balanced in transverse momentum to the probe. We show that the existing 2015 LHC data set of p p collisions with ∫L d t =4 fb-1 should already have powerful sensitivity to a generic Z' model which couples only to quarks, for Z' masses ranging from 20 - 500 GeV /c2 .

  10. Boosted X Waves in Nonlinear Optical Systems

    SciTech Connect

    Arevalo, Edward

    2010-01-15

    X waves are spatiotemporal optical waves with intriguing superluminal and subluminal characteristics. Here we theoretically show that for a given initial carrier frequency of the system localized waves with genuine superluminal or subluminal group velocity can emerge from initial X waves in nonlinear optical systems with normal group velocity dispersion. Moreover, we show that this temporal behavior depends on the wave detuning from the carrier frequency of the system and not on the particular X-wave biconical form. A spatial counterpart of this behavior is also found when initial X waves are boosted in the plane transverse to the direction of propagation, so a fully spatiotemporal motion of localized waves can be observed.

  11. Boosting jet power in black hole spacetimes.

    PubMed

    Neilsen, David; Lehner, Luis; Palenzuela, Carlos; Hirschmann, Eric W; Liebling, Steven L; Motl, Patrick M; Garrett, Travis

    2011-08-01

    The extraction of rotational energy from a spinning black hole via the Blandford-Znajek mechanism has long been understood as an important component in models to explain energetic jets from compact astrophysical sources. Here we show more generally that the kinetic energy of the black hole, both rotational and translational, can be tapped, thereby producing even more luminous jets powered by the interaction of the black hole with its surrounding plasma. We study the resulting Poynting jet that arises from single boosted black holes and binary black hole systems. In the latter case, we find that increasing the orbital angular momenta of the system and/or the spins of the individual black holes results in an enhanced Poynting flux.

  12. Boosted X waves in nonlinear optical systems.

    PubMed

    Arévalo, Edward

    2010-01-15

    X waves are spatiotemporal optical waves with intriguing superluminal and subluminal characteristics. Here we theoretically show that for a given initial carrier frequency of the system localized waves with genuine superluminal or subluminal group velocity can emerge from initial X waves in nonlinear optical systems with normal group velocity dispersion. Moreover, we show that this temporal behavior depends on the wave detuning from the carrier frequency of the system and not on the particular X-wave biconical form. A spatial counterpart of this behavior is also found when initial X waves are boosted in the plane transverse to the direction of propagation, so a fully spatiotemporal motion of localized waves can be observed.

  13. On the maximum regulation range in boost and buck-boost converters

    NASA Astrophysics Data System (ADS)

    Ninomiya, T.; Harada, K.; Nakahara, M.

    Two types of instability conditions in boost and buck-boost converters with a feedback loop are analyzed by means of the steady-state characteristic and dynamic small-signal modeling. Type I instability involves a drastic voltage drop, and in Type II instability, a limit-cycle oscillation arises and the output voltage oscillates at low frequencies. The maximum regulation range is derived analytically for the load variation and verified experimentally. For high feedback gain, it is determined by the Type II instability condition, whereas for low feedback gain, it is determined by the Type I instability condition. Type II instability can be suppressed by decreasing the reactor inductance or by increasing the capacitance of a smoothing capacitor. However, Type I instability is found to be independent of these values.

  14. Boosting for multi-graph classification.

    PubMed

    Wu, Jia; Pan, Shirui; Zhu, Xingquan; Cai, Zhihua

    2015-03-01

    In this paper, we formulate a novel graph-based learning problem, multi-graph classification (MGC), which aims to learn a classifier from a set of labeled bags each containing a number of graphs inside the bag. A bag is labeled positive, if at least one graph in the bag is positive, and negative otherwise. Such a multi-graph representation can be used for many real-world applications, such as webpage classification, where a webpage can be regarded as a bag with texts and images inside the webpage being represented as graphs. This problem is a generalization of multi-instance learning (MIL) but with vital differences, mainly because instances in MIL share a common feature space whereas no feature is available to represent graphs in a multi-graph bag. To solve the problem, we propose a boosting based multi-graph classification framework (bMGC). Given a set of labeled multi-graph bags, bMGC employs dynamic weight adjustment at both bag- and graph-levels to select one subgraph in each iteration as a weak classifier. In each iteration, bag and graph weights are adjusted such that an incorrectly classified bag will receive a higher weight because its predicted bag label conflicts to the genuine label, whereas an incorrectly classified graph will receive a lower weight value if the graph is in a positive bag (or a higher weight if the graph is in a negative bag). Accordingly, bMGC is able to differentiate graphs in positive and negative bags to derive effective classifiers to form a boosting model for MGC. Experiments and comparisons on real-world multi-graph learning tasks demonstrate the algorithm performance.

  15. Series-Connected Buck Boost Regulators

    NASA Technical Reports Server (NTRS)

    Birchenough, Arthur G.

    2005-01-01

    A series-connected buck boost regulator (SCBBR) is an electronic circuit that bucks a power-supply voltage to a lower regulated value or boosts it to a higher regulated value. The concept of the SCBBR is a generalization of the concept of the SCBR, which was reported in "Series-Connected Boost Regulators" (LEW-15918), NASA Tech Briefs, Vol. 23, No. 7 (July 1997), page 42. Relative to prior DC-voltage-regulator concepts, the SCBBR concept can yield significant reductions in weight and increases in power-conversion efficiency in many applications in which input/output voltage ratios are relatively small and isolation is not required, as solar-array regulation or battery charging with DC-bus regulation. Usually, a DC voltage regulator is designed to include a DC-to-DC converter to reduce its power loss, size, and weight. Advances in components, increases in operating frequencies, and improved circuit topologies have led to continual increases in efficiency and/or decreases in the sizes and weights of DC voltage regulators. The primary source of inefficiency in the DC-to-DC converter portion of a voltage regulator is the conduction loss and, especially at high frequencies, the switching loss. Although improved components and topology can reduce the switching loss, the reduction is limited by the fact that the converter generally switches all the power being regulated. Like the SCBR concept, the SCBBR concept involves a circuit configuration in which only a fraction of the power is switched, so that the switching loss is reduced by an amount that is largely independent of the specific components and circuit topology used. In an SCBBR, the amount of power switched by the DC-to-DC converter is only the amount needed to make up the difference between the input and output bus voltage. The remaining majority of the power passes through the converter without being switched. The weight and power loss of a DC-to-DC converter are determined primarily by the amount of power

  16. HIV-1 Env DNA vaccine plus protein boost delivered by EP expands B- and T-cell responses and neutralizing phenotype in vivo.

    PubMed

    Muthumani, Kar; Wise, Megan C; Broderick, Kate E; Hutnick, Natalie; Goodman, Jonathan; Flingai, Seleeke; Yan, Jian; Bian, Chaoran B; Mendoza, Janess; Tingey, Colleen; Wilson, Christine; Wojtak, Krzysztof; Sardesai, Niranjan Y; Weiner, David B

    2013-01-01

    An effective HIV vaccine will most likely require the induction of strong T-cell responses, broadly neutralizing antibodies (bNAbs), and the elicitation of antibody-dependent cellular cytotoxicity (ADCC). Previously, we demonstrated the induction of strong HIV/SIV cellular immune responses in macaques and humans using synthetic consensus DNA immunogens delivered via adaptive electroporation (EP). However, the ability of this improved DNA approach to prime for relevant antibody responses has not been previously studied. Here, we investigate the immunogenicity of consensus DNA constructs encoding gp140 sequences from HIV-1 subtypes A, B, C and D in a DNA prime-protein boost vaccine regimen. Mice and guinea pigs were primed with single- and multi-clade DNA via EP and boosted with recombinant gp120 protein. Sera were analyzed for gp120 binding and induction of neutralizing antibody activity. Immunization with recombinant Env protein alone induced low-titer binding antibodies with limited neutralization breath. In contrast, the synthetic DNA prime-protein boost protocol induced significantly higher antibody binding titers. Furthermore, sera from DNA prime-protein boost groups were able to neutralize a broader range of viruses in a panel of tier 1 clade B viruses as well as multiple tier 1 clade A and clade C viruses. Further investigation of synthetic DNA prime plus adaptive EP plus protein boost appears warranted. PMID:24391921

  17. HIV-1 Env DNA Vaccine plus Protein Boost Delivered by EP Expands B- and T-Cell Responses and Neutralizing Phenotype In Vivo

    PubMed Central

    Muthumani, Kar; Wise, Megan C.; Broderick, Kate E.; Hutnick, Natalie; Goodman, Jonathan; Flingai, Seleeke; Yan, Jian; Bian, Chaoran B.; Mendoza, Janess; Tingey, Colleen; Wilson, Christine; Wojtak, Krzysztof; Sardesai, Niranjan Y.; Weiner, David B.

    2013-01-01

    An effective HIV vaccine will most likely require the induction of strong T-cell responses, broadly neutralizing antibodies (bNAbs), and the elicitation of antibody-dependent cellular cytotoxicity (ADCC). Previously, we demonstrated the induction of strong HIV/SIV cellular immune responses in macaques and humans using synthetic consensus DNA immunogens delivered via adaptive electroporation (EP). However, the ability of this improved DNA approach to prime for relevant antibody responses has not been previously studied. Here, we investigate the immunogenicity of consensus DNA constructs encoding gp140 sequences from HIV-1 subtypes A, B, C and D in a DNA prime-protein boost vaccine regimen. Mice and guinea pigs were primed with single- and multi-clade DNA via EP and boosted with recombinant gp120 protein. Sera were analyzed for gp120 binding and induction of neutralizing antibody activity. Immunization with recombinant Env protein alone induced low-titer binding antibodies with limited neutralization breath. In contrast, the synthetic DNA prime-protein boost protocol induced significantly higher antibody binding titers. Furthermore, sera from DNA prime-protein boost groups were able to neutralize a broader range of viruses in a panel of tier 1 clade B viruses as well as multiple tier 1 clade A and clade C viruses. Further investigation of synthetic DNA prime plus adaptive EP plus protein boost appears warranted. PMID:24391921

  18. Adaptive sharpening of photos

    NASA Astrophysics Data System (ADS)

    Safonov, Ilia V.; Rychagov, Michael N.; Kang, KiMin; Kim, Sang Ho

    2008-01-01

    Sharpness is an important attribute that contributes to the overall impression of printed photo quality. Often it is impossible to estimate sharpness prior to printing. Sometimes it is a complex task for a consumer to obtain accurate sharpening results by editing a photo on a computer. The novel method of adaptive sharpening aimed for photo printers is proposed. Our approach includes 3 key techniques: sharpness level estimation, local tone mapping and boosting of local contrast. Non-reference automatic sharpness level estimation is based on analysis of variations of edges histograms, where edges are produced by high-pass filters with various kernel sizes, array of integrals of logarithm of edges histograms characterizes photo sharpness, machine learning is applied to choose optimal parameters for given printing size and resolution. Local tone mapping with ordering is applied to decrease edge transition slope length without noticeable artifacts and with some noise suppression. Unsharp mask via bilateral filter is applied for boosting of local contrast. This stage does not produce strong halo artifact which is typical for the traditional unsharp mask filter. The quality of proposed approach is evaluated by surveying observer's opinions. According to obtained replies the proposed method enhances the majority of photos.

  19. Refiners boost crude capacity; Petrochemical production up

    SciTech Connect

    Corbett, R.A.

    1988-03-21

    Continuing demand strength in refined products and petrochemical markets caused refiners to boost crude-charging capacity slightly again last year, and petrochemical producers to increase production worldwide. Product demand strength is, in large part, due to stable product prices resulting from a stabilization of crude oil prices. Crude prices strengthened somewhat in 1987. That, coupled with fierce product competition, unfortunately drove refining margins negative in many regions of the U.S. during the last half of 1987. But with continued strong demand for gasoline, and an increased demand for higher octane gasoline, margins could turn positive by 1989 and remain so for a few years. U.S. refiners also had to have facilities in place to meet the final requirements of the U.S. Environmental Protection Agency's lead phase-down rules on Jan. 1, 1988. In petrochemicals, plastics demand dept basic petrochemical plants at good utilization levels worldwide. U.S. production of basics such as ethylene and propylene showed solid increases. Many of the derivatives of the basic petrochemical products also showed good production gains. Increased petrochemical production and high plant utilization rates didn't spur plant construction projects, however. Worldwide petrochemical plant projects declined slightly from 1986 figures.

  20. Every Day in The Womb Boosts Babies' Brain Development

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_161778.html Every Day in the Womb Boosts Babies' Brain Development: Study ... What this study shows us is that every day and every week of in utero development is ...

  1. Could Slight Brain Zap During Sleep Boost Memory?

    MedlinePlus

    ... medlineplus.gov/news/fullstory_160135.html Could Slight Brain Zap During Sleep Boost Memory? Small study says ... HealthDay News) -- Stimulating a targeted area of the brain with small doses of weak electricity while you ...

  2. Zika's Delivery Via Mosquito Bite May Boost Its Effect

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_159484.html Zika's Delivery Via Mosquito Bite May Boost Its Effect ... The inflammation caused by a mosquito bite helps Zika and other viruses spread through the body more ...

  3. Insurance Mandates Boost U.S. Autism Diagnoses

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_159812.html Insurance Mandates Boost U.S. Autism Diagnoses Early treatment provides ... the Penn researchers analyzed inpatient and outpatient health insurance claims from 2008 through 2012 for more than ...

  4. Testosterone Therapy May Boost Older Men's Sex Lives

    MedlinePlus

    ... 159622.html Testosterone Therapy May Boost Older Men's Sex Lives Gel hormone treatment led to improved libido ... experienced a moderate but significant improvement in their sex drive, sexual activity and erectile function compared to ...

  5. High-temperature alloys: Single-crystal performance boost

    NASA Astrophysics Data System (ADS)

    Schütze, Michael

    2016-08-01

    Titanium aluminide alloys are lightweight and have attractive properties for high-temperature applications. A new growth method that enables single-crystal production now boosts their mechanical performance.

  6. Our intraoperative boost radiotherapy experience and applications

    PubMed Central

    Günay, Semra; Alan, Ömür; Yalçın, Orhan; Türkmen, Aygen; Dizdar, Nihal

    2016-01-01

    Objective: To present our experience since November 2013, and case selection criteria for intraoperative boost radiotherapy (IObRT) that significantly reduces the local recurrence rate after breast conserving surgery in patients with breast cancer. Material and Methods: Patients who were suitable for IObRT were identified within the group of patients who were selected for breast conserving surgery at our breast council. A MOBETRON (mobile linear accelerator for IObRT) was used for IObRt during surgery. Results: Patients younger than 60 years old with <3 cm invasive ductal cancer in one focus (or two foci within 2 cm), with a histologic grade of 2–3, and a high possibility of local recurrence were admitted for IObRT application. Informed consent was obtained from all participants. Lumpectomy and sentinel lymph node biopsy was performed and advancement flaps were prepared according to the size and inclination of the conus following evaluation of tumor size and surgical margins by pathology. Distance to the thoracic wall was measured, and a radiation oncologist and radiation physicist calculated the required dose. Anesthesia was regulated with slower ventilation frequency, without causing hypoxia. The skin and incision edges were protected, the field was radiated (with 6 MeV electron beam of 10 Gy) and the incision was closed. In our cases, there were no major postoperative surgical or early radiotherapy related complications. Conclusion: The completion of another stage of local therapy with IObRT during surgery positively effects sequencing of other treatments like chemotherapy, hormonotherapy and radiotherapy, if required. IObRT increases disease free and overall survival, as well as quality of life in breast cancer patients. PMID:26985156

  7. Boosting Tumor-Specific Immunity Using PDT

    PubMed Central

    Maeding, Nicole; Verwanger, Thomas; Krammer, Barbara

    2016-01-01

    Photodynamic therapy (PDT) is a cancer treatment with a long-standing history. It employs the application of nontoxic components, namely a light-sensitive photosensitizer and visible light, to generate reactive oxygen species (ROS). These ROS lead to tumor cell destruction, which is accompanied by the induction of an acute inflammatory response. This inflammatory process sends a danger signal to the innate immune system, which results in activation of specific cell types and release of additional inflammatory mediators. Activation of the innate immune response is necessary for subsequent induction of the adaptive arm of the immune system. This includes the priming of tumor-specific cytotoxic T lymphocytes (CTL) that have the capability to directly recognize and kill cells which display an altered self. The past decades have brought increasing appreciation for the importance of the generation of an adaptive immune response for long-term tumor control and induction of immune memory to combat recurrent disease. This has led to considerable effort to elucidate the immune effects PDT treatment elicits. In this review we deal with the progress which has been made during the past 20 years in uncovering the role of PDT in the induction of the tumor-specific immune response, with special emphasis on adaptive immunity. PMID:27782066

  8. Boosted Fast Flux Loop Final Report

    SciTech Connect

    Boosted Fast Flux Loop Project Staff

    2009-09-01

    The Boosted Fast Flux Loop (BFFL) project was initiated to determine basic feasibility of designing, constructing, and installing in a host irradiation facility, an experimental vehicle that can replicate with reasonable fidelity the fast-flux test environment needed for fuels and materials irradiation testing for advanced reactor concepts. Originally called the Gas Test Loop (GTL) project, the activity included (1) determination of requirements that must be met for the GTL to be responsive to potential users, (2) a survey of nuclear facilities that may successfully host the GTL, (3) conceptualizing designs for hardware that can support the needed environments for neutron flux intensity and energy spectrum, atmosphere, flow, etc. needed by the experimenters, and (4) examining other aspects of such a system, such as waste generation and disposal, environmental concerns, needs for additional infrastructure, and requirements for interfacing with the host facility. A revised project plan included requesting an interim decision, termed CD-1A, that had objectives of' establishing the site for the project at the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL), deferring the CD 1 application, and authorizing a research program that would resolve the most pressing technical questions regarding GTL feasibility, including issues relating to the use of booster fuel in the ATR. Major research tasks were (1) hydraulic testing to establish flow conditions through the booster fuel, (2) mini-plate irradiation tests and post-irradiation examination to alleviate concerns over corrosion at the high heat fluxes planned, (3) development and demonstration of booster fuel fabrication techniques, and (4) a review of the impact of the GTL on the ATR safety basis. A revised cooling concept for the apparatus was conceptualized, which resulted in renaming the project to the BFFL. Before the subsequent CD-1 approval request could be made, a decision was made in April 2006

  9. Gene network-based cancer prognosis analysis with sparse boosting

    PubMed Central

    Ma, Shuangge; Huang, Yuan; Huang, Jian; Fang, Kuangnan

    2013-01-01

    Summary High-throughput gene profiling studies have been extensively conducted, searching for markers associated with cancer development and progression. In this study, we analyse cancer prognosis studies with right censored survival responses. With gene expression data, we adopt the weighted gene co-expression network analysis (WGCNA) to describe the interplay among genes. In network analysis, nodes represent genes. There are subsets of nodes, called modules, which are tightly connected to each other. Genes within the same modules tend to have co-regulated biological functions. For cancer prognosis data with gene expression measurements, our goal is to identify cancer markers, while properly accounting for the network module structure. A two-step sparse boosting approach, called Network Sparse Boosting (NSBoost), is proposed for marker selection. In the first step, for each module separately, we use a sparse boosting approach for within-module marker selection and construct module-level ‘super markers ’. In the second step, we use the super markers to represent the effects of all genes within the same modules and conduct module-level selection using a sparse boosting approach. Simulation study shows that NSBoost can more accurately identify cancer-associated genes and modules than alternatives. In the analysis of breast cancer and lymphoma prognosis studies, NSBoost identifies genes with important biological implications. It outperforms alternatives including the boosting and penalization approaches by identifying a smaller number of genes/modules and/or having better prediction performance. PMID:22950901

  10. Use of the Lorentz-Boosted Frame Transformation to Simulate Free-Electron Laser Amplifier Physics

    SciTech Connect

    Fawley, W. M.; Vay, J.-L.

    2009-01-22

    Recently it has been pointed out that numerical simulation of some systems containing charged particles with highly relativistic directed motion can by speeded up by orders of magnitude by choice of the proper Lorentz boosted frame. A particularly good example is that of short wavelength free-electron lasers (FELs) in which a high energy (E{sub 0}{>=}250 MeV) electron beam interacts with a static magnetic undulator. In the optimal boost frame with Lorentz factor {gamma}F, the red-shifted FEL radiation and blue shifted undulator have identical wavelengths and the number of required time-steps (presuming the Courant condition applies) decreases by a factor of {gamma}{sub F}{sup 2} for fully electromagnetic simulation.We have adapted the WARP code to apply this method to several FEL problems including coherent spontaneous emission (CSE) from pre-bunched e-beams, and strong exponential gain in a single pass amplifier configuration. We discuss our results and compare with those from the 'standard' FEL simulation approach which adopts the eikonal approximation for propagation of the radiation field.

  11. High efficiency and low electromagnetic interference boost DC-DC converter

    NASA Astrophysics Data System (ADS)

    Yajun, Li; Xinquan, Lai; Qiang, Ye; Bing, Yuan

    2014-04-01

    A synchronous boost DC-DC converter with an adaptive dead time control (DTC) circuit and anti-ringing circuit is presented. The DTC circuit is used to provide adjustable dead time and zero inductor current detection for power transistors and therefore, a high efficiency is achieved by minimizing power losses, such as the shoot-through current loss, the body diode conduction loss, the charge-sharing loss and the reverse inductor current loss. Simultaneously, a novel anti-ringing circuit controlled by the switching sequence of power transistors is developed to suppress the ringing when the converter enters the discontinuous conduction mode (DCM) for low electromagnetic interference (EMI) and additional power savings. The proposed converter has been fabricated in a 0.6 μm CDMOS technology. Simulation and experimental results show that the power efficiency of the boost converter is above 81% under different load currents from 10 to 250 mA and a peak efficiency of 90% is achieved at about 100 mA. Moreover, the ringing is easily suppressed by the anti-ringing circuit and therefore the EMI noise is attenuated.

  12. Use of the Lorentz-Boosted Frame Transformation to Simulate Free-Electron Laser Amplifier Physics

    SciTech Connect

    Fawley, W.M.; Vay, J.-L.

    2008-07-27

    Recently [1]it has been pointed out that numerical simulation of some systems containing charged particles with highly relativistic directed motion can by speeded up by orders of magnitude by choice of the proper Lorentz boosted frame. A particularly good example is that of short wavelength free-electron lasers (FELs) in which a high energy (E0>_ 250 MeV) electron beam interacts with a static magnetic undulator. In the optimal boost frame with Lorentz factor gamma F, the red-shifted FEL radiation and blue shifted undulator have identical wavelengths and the number of required time-steps (presuming the Courant condition applies) decreases by a factor of g2 F for fullyelectromagnetic simulation. We have adapted the WARP code [2]to apply this method to several FEL problems including coherent spontaneous emission (CSE) from pre-bunched e-beams, and strong exponential gain in a single pass amplifier configuration. We discuss our results and compare with those from the"standard" FEL simulation approach which adopts the eikonal approximation for propagation ofthe radiation field.

  13. (In)Direct detection of boosted dark matter

    NASA Astrophysics Data System (ADS)

    Agashe, Kaustubh; Cui, Yanou; Necib, Lina; Thaler, Jesse

    2016-05-01

    We present a new multi-component dark matter model with a novel experimental signature that mimics neutral current interactions at neutrino detectors. In our model, the dark matter is composed of two particles, a heavier dominant component that annihilates to produce a boosted lighter component that we refer to as boosted dark matter. The lighter component is relativistic and scatters off electrons in neutrino experiments to produce Cherenkov light. This model combines the indirect detection of the dominant component with the direct detection of the boosted dark matter. Directionality can be used to distinguish the dark matter signal from the atmospheric neutrino background. We discuss the viable region of parameter space in current and future experiments.

  14. Behavior of entanglement and Cooper pairs under relativistic boosts

    SciTech Connect

    Palge, Veiko; Dunningham, Jacob A.; Vedral, Vlatko

    2011-10-15

    Recent work [J. A. Dunningham, V. Palge, and V. Vedral, Phys. Rev. A 80, 044302 (2009)] has shown how single-particle entangled states are transformed when boosted in relativistic frames for certain restricted geometries. Here we extend that work to consider completely general inertial boosts. We then apply our single-particle results to multiparticle entanglements by focusing on Cooper pairs of electrons. We show that a standard Cooper pair state consisting of a spin-singlet acquires spin-triplet components in a relativistically boosted inertial frame, regardless of the geometry. We also show that, if we start with a spin-triplet pair, two out of the three triplet states acquire a singlet component, the size of which depends on the geometry. This transformation between the different singlet and triplet superconducting pairs may lead to a better understanding of unconventional superconductivity.

  15. Boosted Fast Flux Loop Alternative Cooling Assessment

    SciTech Connect

    Glen R. Longhurst; Donna Post Guillen; James R. Parry; Douglas L. Porter; Bruce W. Wallace

    2007-08-01

    The Gas Test Loop (GTL) Project was instituted to develop the means for conducting fast neutron irradiation tests in a domestic radiation facility. It made use of booster fuel to achieve the high neutron flux, a hafnium thermal neutron absorber to attain the high fast-to-thermal flux ratio, a mixed gas temperature control system for maintaining experiment temperatures, and a compressed gas cooling system to remove heat from the experiment capsules and the hafnium thermal neutron absorber. This GTL system was determined to provide a fast (E > 0.1 MeV) flux greater than 1.0E+15 n/cm2-s with a fast-to-thermal flux ratio in the vicinity of 40. However, the estimated system acquisition cost from earlier studies was deemed to be high. That cost was strongly influenced by the compressed gas cooling system for experiment heat removal. Designers were challenged to find a less expensive way to achieve the required cooling. This report documents the results of the investigation leading to an alternatively cooled configuration, referred to now as the Boosted Fast Flux Loop (BFFL). This configuration relies on a composite material comprised of hafnium aluminide (Al3Hf) in an aluminum matrix to transfer heat from the experiment to pressurized water cooling channels while at the same time providing absorption of thermal neutrons. Investigations into the performance this configuration might achieve showed that it should perform at least as well as its gas-cooled predecessor. Physics calculations indicated that the fast neutron flux averaged over the central 40 cm (16 inches) relative to ATR core mid-plane in irradiation spaces would be about 1.04E+15 n/cm2-s. The fast-to-thermal flux ratio would be in excess of 40. Further, the particular configuration of cooling channels was relatively unimportant compared with the total amount of water in the apparatus in determining performance. Thermal analyses conducted on a candidate configuration showed the design of the water coolant and

  16. The Lateral Decubitus Breast Boost: Description, Rationale, and Efficacy

    SciTech Connect

    Ludwig, Michelle S.; McNeese, Marsha D.; Buchholz, Thomas A.; Perkins, George H.; Strom, Eric A.

    2010-01-15

    Purpose: To describe and evaluate the modified lateral decubitus boost, a breast irradiation technique. Patients are repositioned and resimulated for electron boost to minimize the necessary depth for the electron beam and optimize target volume coverage. Methods and Materials: A total of 2,606 patients were treated with post-lumpectomy radiation at our institution between January 1, 2000, and February 1, 2008. Of these, 231 patients underwent resimulation in the lateral decubitus position with electron boost. Distance from skin to the maximal depth of target volume was measured in both the original and boost plans. Age, body mass index (BMI), boost electron energy, and skin reaction were evaluated. Results: Resimulation in the lateral decubitus position reduced the distance from skin to maximal target volume depth in all patients. Average depth reduction by repositioning was 2.12 cm, allowing for an average electron energy reduction of approximately 7 MeV. Mean skin entrance dose was reduced from about 90% to about 85% (p < 0.001). Only 14 patients (6%) experienced moist desquamation in the boost field at the end of treatment. Average BMI of these patients was 30.4 (range, 17.8-50.7). BMI greater than 30 was associated with more depth reduction by repositioning and increased risk of moist desquamation. Conclusions: The lateral decubitus position allows for a decrease in the distance from the skin to the target volume depth, improving electron coverage of the tumor bed while reducing skin entrance dose. This is a well-tolerated regimen for a patient population with a high BMI or deep tumor location.

  17. Self-boosting vaccines and their implications for herd immunity.

    PubMed

    Arinaminpathy, Nimalan; Lavine, Jennie S; Grenfell, Bryan T

    2012-12-01

    Advances in vaccine technology over the past two centuries have facilitated far-reaching impact in the control of many infections, and today's emerging vaccines could likewise open new opportunities in the control of several diseases. Here we consider the potential, population-level effects of a particular class of emerging vaccines that use specific viral vectors to establish long-term, intermittent antigen presentation within a vaccinated host: in essence, "self-boosting" vaccines. In particular, we use mathematical models to explore the potential role of such vaccines in situations where current immunization raises only relatively short-lived protection. Vaccination programs in such cases are generally limited in their ability to raise lasting herd immunity. Moreover, in certain cases mass vaccination can have the counterproductive effect of allowing an increase in severe disease, through reducing opportunities for immunity to be boosted through natural exposure to infection. Such dynamics have been proposed, for example, in relation to pertussis and varicella-zoster virus. In this context we show how self-boosting vaccines could open qualitatively new opportunities, for example by broadening the effective duration of herd immunity that can be achieved with currently used immunogens. At intermediate rates of self-boosting, these vaccines also alleviate the potential counterproductive effects of mass vaccination, through compensating for losses in natural boosting. Importantly, however, we also show how sufficiently high boosting rates may introduce a new regime of unintended consequences, wherein the unvaccinated bear an increased disease burden. Finally, we discuss important caveats and data needs arising from this work.

  18. 2001 BUDGET: Research Gets Hefty Boost in 2001 Defense Budget.

    PubMed

    Malakoff, D

    2000-09-01

    Next year's $289 billion defense budget, which President Bill Clinton signed last month, includes big boosts for a host of science programs, from endangered species research to developing laser weapons. And with the two major presidential candidates pledging further boosts, the Pentagon's portfolio is attracting increasing attention from the life sciences community as well. But some analysts worry that Congress and the Pentagon may be shortchanging long-term, high-risk research in favor of projects with a more certain payoff. PMID:17811142

  19. Early boost and slow consolidation in motor skill learning.

    PubMed

    Hotermans, Christophe; Peigneux, Philippe; Maertens de Noordhout, Alain; Moonen, Gustave; Maquet, Pierre

    2006-01-01

    Motorskill learning is a dynamic process that continues covertly after training has ended and eventually leads to delayed increments in performance. Current theories suggest that this off-line improvement takes time and appears only after several hours. Here we show an early transient and short-lived boost in performance, emerging as early as 5-30 min after training but no longer observed 4 h later. This early boost is predictive of the performance achieved 48 h later, suggesting its functional relevance for memory processes.

  20. Boosted Objects: A Probe of Beyond the Standard Model Physics

    SciTech Connect

    Abdesselam, A.; Kuutmann, E.Bergeaas; Bitenc, U.; Brooijmans, G.; Butterworth, J.; Bruckman de Renstrom, P.; Buarque Franzosi, D.; Buckingham, R.; Chapleau, B.; Dasgupta, M.; Davison, A.; Dolen, J.; Ellis, S.; Fassi, F.; Ferrando, J.; Frandsen, M.T.; Frost, J.; Gadfort, T.; Glover, N.; Haas, A.; Halkiadakis, E.; /more authors..

    2012-06-12

    We present the report of the hadronic working group of the BOOST2010 workshop held at the University of Oxford in June 2010. The first part contains a review of the potential of hadronic decays of highly boosted particles as an aid for discovery at the LHC and a discussion of the status of tools developed to meet the challenge of reconstructing and isolating these topologies. In the second part, we present new results comparing the performance of jet grooming techniques and top tagging algorithms on a common set of benchmark channels. We also study the sensitivity of jet substructure observables to the uncertainties in Monte Carlo predictions.

  1. Experiments with repeating weighted boosting search for optimization in signal processing applications.

    PubMed

    Chen, Sheng; Wang, Xunxian; Harris, Chris J

    2005-08-01

    Many signal processing applications pose optimization problems with multimodal and nonsmooth cost functions. Gradient methods are ineffective in these situations, and optimization methods that require no gradient and can achieve a global optimal solution are highly desired to tackle these difficult problems. The paper proposes a guided global search optimization technique, referred to as the repeated weighted boosting search. The proposed optimization algorithm is extremely simple and easy to implement, involving a minimum programming effort. Heuristic explanation is given for the global search capability of this technique. Comparison is made with the two better known and widely used guided global search techniques, known as the genetic algorithm and adaptive simulated annealing, in terms of the requirements for algorithmic parameter tuning. The effectiveness of the proposed algorithm as a global optimizer are investigated through several application examples.

  2. Speckle Reduction and Structure Enhancement by Multichannel Median Boosted Anisotropic Diffusion

    NASA Astrophysics Data System (ADS)

    Yang, Zhi; Fox, Martin D.

    2004-12-01

    We propose a new approach to reduce speckle noise and enhance structures in speckle-corrupted images. It utilizes a median-anisotropic diffusion compound scheme. The median-filter-based reaction term acts as a guided energy source to boost the structures in the image being processed. In addition, it regularizes the diffusion equation to ensure the existence and uniqueness of a solution. We also introduce a decimation and back reconstruction scheme to further enhance the processing result. Before the iteration of the diffusion process, the image is decimated and a subpixel shifted image set is formed. This allows a multichannel parallel diffusion iteration, and more importantly, the speckle noise is broken into impulsive or salt-pepper noise, which is easy to remove by median filtering. The advantage of the proposed technique is clear when it is compared to other diffusion algorithms and the well-known adaptive weighted median filtering (AWMF) scheme in both simulation and real medical ultrasound images.

  3. OKVAR-Boost: a novel boosting algorithm to infer nonlinear dynamics and interactions in gene regulatory networks

    PubMed Central

    Lim, Néhémy; Şenbabaoğlu, Yasin; Michailidis, George; d’Alché-Buc, Florence

    2013-01-01

    Motivation: Reverse engineering of gene regulatory networks remains a central challenge in computational systems biology, despite recent advances facilitated by benchmark in silico challenges that have aided in calibrating their performance. A number of approaches using either perturbation (knock-out) or wild-type time-series data have appeared in the literature addressing this problem, with the latter using linear temporal models. Nonlinear dynamical models are particularly appropriate for this inference task, given the generation mechanism of the time-series data. In this study, we introduce a novel nonlinear autoregressive model based on operator-valued kernels that simultaneously learns the model parameters, as well as the network structure. Results: A flexible boosting algorithm (OKVAR-Boost) that shares features from L2-boosting and randomization-based algorithms is developed to perform the tasks of parameter learning and network inference for the proposed model. Specifically, at each boosting iteration, a regularized Operator-valued Kernel-based Vector AutoRegressive model (OKVAR) is trained on a random subnetwork. The final model consists of an ensemble of such models. The empirical estimation of the ensemble model’s Jacobian matrix provides an estimation of the network structure. The performance of the proposed algorithm is first evaluated on a number of benchmark datasets from the DREAM3 challenge and then on real datasets related to the In vivo Reverse-Engineering and Modeling Assessment (IRMA) and T-cell networks. The high-quality results obtained strongly indicate that it outperforms existing approaches. Availability: The OKVAR-Boost Matlab code is available as the archive: http://amis-group.fr/sourcecode-okvar-boost/OKVARBoost-v1.0.zip. Contact: florence.dalche@ibisc.univ-evry.fr Supplementary information: Supplementary data are available at Bioinformatics online. PMID:23574736

  4. Adaptive Management

    EPA Science Inventory

    Adaptive management is an approach to natural resource management that emphasizes learning through management where knowledge is incomplete, and when, despite inherent uncertainty, managers and policymakers must act. Unlike a traditional trial and error approach, adaptive managem...

  5. Retrieval boosted computer-aided diagnosis of clustered microcalcifications for breast cancer

    PubMed Central

    Jing, Hao; Yang, Yongyi; Nishikawa, Robert M.

    2012-01-01

    Purpose: The authors propose an image-retrieval based approach for case-adaptive classifier design in computer-aided diagnosis (CADx). The conventional approach in CADx is to first train a pattern-classifier based on a set of existing training samples and then apply this classifier to subsequent new cases. The purpose of this work is to improve the classification accuracy of a CADx classifier by making use of a set of known cases retrieved from a reference library that are similar to the case under consideration. Methods: In the proposed approach, the authors will first apply image-retrieval to obtain a set of lesion images from a library of known cases that have similar image features to a case being diagnosed (i.e., query). These retrieved cases are then used to optimize a pattern-classifier toward boosting its classification accuracy on the query case. The basic idea is to put more emphasis on those cases that are similar to the query. The proposed approach is demonstrated first using a linear classifier and then extended to a nonlinear classifier induced by kernel principal component analysis. Results: The proposed retrieval-driven approach was tested on a library of mammogram images from 1006 cases (646 benign and 360 malignant) obtained from multiple institutions and was demonstrated to yield significant improvement in classification performance. Measured by the area under the receiver operating characteristic curve (AUC), the case-adaptive approach could boost the classification performance of a linear classifier from AUC = 0.7415 to AUC = 0.7807; similar improvement was also obtained for a nonlinear classifier, with AUC boosted from 0.7527 to 0.7838. Conclusions: Use of additional cases from a reference library that have similar image features can improve the classification accuracy of a CADx classifier on a query case. It can even outperform retraining the classifier with all the cases from the entire reference library. This implies that cases with

  6. Boost compensator for use with internal combustion engine with supercharger

    SciTech Connect

    Asami, T.

    1988-04-12

    A boost compensator for controlling the position of a control rack of a fuel injection pump to supply fuel to an internal combustion with a supercharger in response to a boost pressure to be applied to the engine is described. The control rack is movable in a first direction increasing an amount of fuel to be supplied by the fuel injection pump to the engine and in a second direction, opposite to the first direction, decreasing the amount of fuel. The boost compensator comprises: a push rod disposed for forward and rearward movement in response to the boost pressure; a main lever disposed for angular movement about a first pivot; an auxiliary lever disposed for angular movement about a second pivot; return spring means associated with the first portion of the auxiliary lever for resiliently biasing same in one direction about the second pivot; and abutment means mounted on the second portion of the auxiliary lever and engageable with the second portion of the main lever.

  7. Boosting Teachers' Self-Esteem: A Dropout Prevention Strategy.

    ERIC Educational Resources Information Center

    Ruben, Ann Moliver

    Good teachers leave teaching not because pay is low but because of poor working conditions and too little recognition. Since students can be strongly affected by teachers, teachers who feel negatively about themselves can adversely affect students. A five-evening workshop was developed in Dade County, Florida to boost teachers' self-esteem and to…

  8. Balance-Boosting Footwear Tips for Older People

    MedlinePlus

    ... Home » Learn About Feet » Tips for Healthy Feet Balance-Boosting Footwear Tips for Older People Balance in all aspects of life is a good ... mental equilibrium isn't the only kind of balance that's important in life. Good physical balance can ...

  9. Inverse ultravelocity slings for boost-phase defense

    SciTech Connect

    Canavan, G.H.

    1991-04-01

    Existing booster technology, brilliant pebble interceptors, survivable platforms, and developed warning, command, control, and communication could provide boost-phase defensives with the capability and flexibility required to significantly reduce the effectiveness of submarine and theater attacks. 7 refs., 2 figs.

  10. Early Boost and Slow Consolidation in Motor Skill Learning

    ERIC Educational Resources Information Center

    Hotermans, Christophe; Peigneux, Philippe; de Noordhout, Alain Maertens; Moonen, Gustave; Maquet, Pierre

    2006-01-01

    Motor skill learning is a dynamic process that continues covertly after training has ended and eventually leads to delayed increments in performance. Current theories suggest that this off-line improvement takes time and appears only after several hours. Here we show an early transient and short-lived boost in performance, emerging as early as…

  11. Boosting NAD(+) for the prevention and treatment of liver cancer.

    PubMed

    Djouder, Nabil

    2015-01-01

    Hepatocellular carcinoma (HCC) is the third leading cause of cancer death worldwide yet has limited therapeutic options. We recently demonstrated that inhibition of de novo nicotinamide adenine dinucleotide (NAD(+)) synthesis is responsible for DNA damage, thereby initiating hepatocarcinogenesis. We propose that boosting NAD(+) levels might be used as a prophylactic or therapeutic approach in HCC. PMID:27308492

  12. Real-World Connections Can Boost Journalism Program.

    ERIC Educational Resources Information Center

    Schrier, Kathy; Bott, Don; McGuire, Tim

    2001-01-01

    Describes various ways scholastic journalism advisers have attempted to make real-world connections to boost their journalism programs: critiques of student publications by invited guest speakers (professional journalists); regional workshops where professionals offer short presentations; local media offering programming or special sections aimed…

  13. Classification of airborne laser scanning data using JointBoost

    NASA Astrophysics Data System (ADS)

    Guo, Bo; Huang, Xianfeng; Zhang, Fan; Sohn, Gunho

    2015-02-01

    The demands for automatic point cloud classification have dramatically increased with the wide-spread use of airborne LiDAR. Existing research has mainly concentrated on a few dominant objects such as terrain, buildings and vegetation. In addition to those key objects, this paper proposes a supervised classification method to identify other types of objects including power-lines and pylons from point clouds using a JointBoost classifier. The parameters for the learning model are estimated with various features computed based on the geometry and echo information of a LiDAR point cloud. In order to overcome the shortcomings stemming from the inclusion of bare ground data before classification, the proposed classifier directly distinguishes terrain using a feature step-off count. Feature selection is conducted using JointBoost to evaluate feature correlations thus improving both classification accuracy and operational efficiency. In this paper, the contextual constraints for objects extracted by graph-cut segmentation are used to optimize the initial classification results obtained by the JointBoost classifier. Our experimental results show that the step-off count significantly contributes to classification. Seventeen effective features are selected for the initial classification results using the JointBoost classifier. Our experiments indicate that the proposed features and method are effective for classification of airborne LiDAR data from complex scenarios.

  14. Could Weight-Loss Surgery Boost Odds of Preemie Birth?

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_160596.html Could Weight-Loss Surgery Boost Odds of Preemie Birth? Monitoring is ... HealthDay News) -- Mothers-to-be who've had weight-loss surgery may have increased odds for premature delivery, ...

  15. Graph ensemble boosting for imbalanced noisy graph stream classification.

    PubMed

    Pan, Shirui; Wu, Jia; Zhu, Xingquan; Zhang, Chengqi

    2015-05-01

    Many applications involve stream data with structural dependency, graph representations, and continuously increasing volumes. For these applications, it is very common that their class distributions are imbalanced with minority (or positive) samples being only a small portion of the population, which imposes significant challenges for learning models to accurately identify minority samples. This problem is further complicated with the presence of noise, because they are similar to minority samples and any treatment for the class imbalance may falsely focus on the noise and result in deterioration of accuracy. In this paper, we propose a classification model to tackle imbalanced graph streams with noise. Our method, graph ensemble boosting, employs an ensemble-based framework to partition graph stream into chunks each containing a number of noisy graphs with imbalanced class distributions. For each individual chunk, we propose a boosting algorithm to combine discriminative subgraph pattern selection and model learning as a unified framework for graph classification. To tackle concept drifting in graph streams, an instance level weighting mechanism is used to dynamically adjust the instance weight, through which the boosting framework can emphasize on difficult graph samples. The classifiers built from different graph chunks form an ensemble for graph stream classification. Experiments on real-life imbalanced graph streams demonstrate clear benefits of our boosting design for handling imbalanced noisy graph stream.

  16. Boosting Imagination: Incorporating Creative Play into the Writing Room

    ERIC Educational Resources Information Center

    Nelson, Angela; Schmidt, Jamie; Verbais, Chad

    2006-01-01

    Incorporating creative play in the writing lab or classroom is a unique way to pique students' interest and boost their imagination. Exercises varying from describing Hershey's Kisses®, to using tape recorders for discussing voice, to using magnetic poetry to practice grammar are all ways that stimulate learning through the lens of play. Play…

  17. Intelligent robotics can boost America's economic growth

    NASA Technical Reports Server (NTRS)

    Erickson, Jon D.

    1994-01-01

    A case is made for strategic investment in intelligent robotics as a part of the solution to the problem of improved global competitiveness for U.S. manufacturing, a critical industrial sector. Similar cases are made for strategic investments in intelligent robotics for field applications, construction, and service industries such as health care. The scope of the country's problems and needs is beyond the capability of the private sector alone, government alone, or academia alone to solve independently of the others. National cooperative programs in intelligent robotics are needed with the private sector supplying leadership direction and aerospace and non-aerospace industries conducting the development. Some necessary elements of such programs are outlined. The National Aeronautics and Space Administration (NASA) and the Lyndon B. Johnson Space Center (JSC) can be key players in such national cooperative programs in intelligent robotics for several reasons: (1) human space exploration missions require supervised intelligent robotics as enabling tools and, hence must develop supervised intelligent robotic systems; (2) intelligent robotic technology is being developed for space applications at JSC (but has a strong crosscutting or generic flavor) that is advancing the state of the art and is producing both skilled personnel and adaptable developmental infrastructure such as integrated testbeds; and (3) a NASA JSC Technology Investment Program in Robotics has been proposed based on commercial partnerships and collaborations for precompetitive, dual-use developments.

  18. Benefit of Radiation Boost After Whole-Breast Radiotherapy

    SciTech Connect

    Livi, Lorenzo; Borghesi, Simona; Saieva, Calogero; Fambrini, Massimiliano; Iannalfi, Alberto; Greto, Daniela; Paiar, Fabiola; Scoccianti, Silvia; Simontacchi, Gabriele; Bianchi, Simonetta; Cataliotti, Luigi; Biti, Giampaolo

    2009-11-15

    Purpose: To determine whether a boost to the tumor bed after breast-conserving surgery (BCS) and radiotherapy (RT) to the whole breast affects local control and disease-free survival. Methods and Materials: A total of 1,138 patients with pT1 to pT2 breast cancer underwent adjuvant RT at the University of Florence. We analyzed only patients with a minimum follow-up of 1 year (range, 1-20 years), with negative surgical margins. The median age of the patient population was 52.0 years (+-7.9 years). The breast cancer relapse incidence probability was estimated by the Kaplan-Meier method, and differences between patient subgroups were compared by the log rank test. Cox regression models were used to evaluate the risk of breast cancer relapse. Results: On univariate survival analysis, boost to the tumor bed reduced breast cancer recurrence (p < 0.0001). Age and tamoxifen also significantly reduced breast cancer relapse (p = 0.01 and p = 0.014, respectively). On multivariate analysis, the boost and the medium age (45-60 years) were found to be inversely related to breast cancer relapse (hazard ratio [HR], 0.27; 95% confidence interval [95% CI], 0.14-0.52, and HR 0.61; 95% CI, 0.37-0.99, respectively). The effect of the boost was more evident in younger patients (HR, 0.15 and 95% CI, 0.03-0.66 for patients <45 years of age; and HR, 0.31 and 95% CI, 0.13-0.71 for patients 45-60 years) on multivariate analyses stratified by age, although it was not a significant predictor in women older than 60 years. Conclusion: Our results suggest that boost to the tumor bed reduces breast cancer relapse and is more effective in younger patients.

  19. 14 CFR 29.695 - Power boost and power-operated control system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Power boost and power-operated control... Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... flight and landing in the event of— (1) Any single failure in the power portion of the system; or (2)...

  20. 14 CFR 27.695 - Power boost and power-operated control system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Power boost and power-operated control... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... flight and landing in the event of— (1) Any single failure in the power portion of the system; or (2)...

  1. 14 CFR 27.695 - Power boost and power-operated control system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Power boost and power-operated control... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... flight and landing in the event of— (1) Any single failure in the power portion of the system; or (2)...

  2. 14 CFR 29.695 - Power boost and power-operated control system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Power boost and power-operated control... Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... flight and landing in the event of— (1) Any single failure in the power portion of the system; or (2)...

  3. 14 CFR 29.695 - Power boost and power-operated control system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Power boost and power-operated control... Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... flight and landing in the event of— (1) Any single failure in the power portion of the system; or (2)...

  4. 14 CFR 29.695 - Power boost and power-operated control system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Power boost and power-operated control... Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... flight and landing in the event of— (1) Any single failure in the power portion of the system; or (2)...

  5. 14 CFR 27.695 - Power boost and power-operated control system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Power boost and power-operated control... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... flight and landing in the event of— (1) Any single failure in the power portion of the system; or (2)...

  6. 14 CFR 27.695 - Power boost and power-operated control system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Power boost and power-operated control... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... flight and landing in the event of— (1) Any single failure in the power portion of the system; or (2)...

  7. Fireplace adapters

    SciTech Connect

    Hunt, R.L.

    1983-12-27

    An adapter is disclosed for use with a fireplace. The stove pipe of a stove standing in a room to be heated may be connected to the flue of the chimney so that products of combustion from the stove may be safely exhausted through the flue and outwardly of the chimney. The adapter may be easily installed within the fireplace by removing the damper plate and fitting the adapter to the damper frame. Each of a pair of bolts has a portion which hooks over a portion of the damper frame and a threaded end depending from the hook portion and extending through a hole in the adapter. Nuts are threaded on the bolts and are adapted to force the adapter into a tight fit with the adapter frame.

  8. Adaptive SPECT

    PubMed Central

    Barrett, Harrison H.; Furenlid, Lars R.; Freed, Melanie; Hesterman, Jacob Y.; Kupinski, Matthew A.; Clarkson, Eric; Whitaker, Meredith K.

    2008-01-01

    Adaptive imaging systems alter their data-acquisition configuration or protocol in response to the image information received. An adaptive pinhole single-photon emission computed tomography (SPECT) system might acquire an initial scout image to obtain preliminary information about the radiotracer distribution and then adjust the configuration or sizes of the pinholes, the magnifications, or the projection angles in order to improve performance. This paper briefly describes two small-animal SPECT systems that allow this flexibility and then presents a framework for evaluating adaptive systems in general, and adaptive SPECT systems in particular. The evaluation is in terms of the performance of linear observers on detection or estimation tasks. Expressions are derived for the ideal linear (Hotelling) observer and the ideal linear (Wiener) estimator with adaptive imaging. Detailed expressions for the performance figures of merit are given, and possible adaptation rules are discussed. PMID:18541485

  9. Spacecraft boost and abort guidance and control systems requirement study, boost dynamics and control analysis study. Exhibit A: Boost dynamics and control anlaysis

    NASA Technical Reports Server (NTRS)

    Williams, F. E.; Price, J. B.; Lemon, R. S.

    1972-01-01

    The simulation developments for use in dynamics and control analysis during boost from liftoff to orbit insertion are reported. Also included are wind response studies of the NR-GD 161B/B9T delta wing booster/delta wing orbiter configuration, the MSC 036B/280 inch solid rocket motor configuration, the MSC 040A/L0X-propane liquid injection TVC configuration, the MSC 040C/dual solid rocket motor configuration, and the MSC 049/solid rocket motor configuration. All of the latest math models (rigid and flexible body) developed for the MSC/GD Space Shuttle Functional Simulator, are included.

  10. Adaptive Computing.

    ERIC Educational Resources Information Center

    Harrell, William

    1999-01-01

    Provides information on various adaptive technology resources available to people with disabilities. (Contains 19 references, an annotated list of 129 websites, and 12 additional print resources.) (JOW)

  11. Contour adaptation.

    PubMed

    Anstis, Stuart

    2013-01-01

    It is known that adaptation to a disk that flickers between black and white at 3-8 Hz on a gray surround renders invisible a congruent gray test disk viewed afterwards. This is contrast adaptation. We now report that adapting simply to the flickering circular outline of the disk can have the same effect. We call this "contour adaptation." This adaptation does not transfer interocularly, and apparently applies only to luminance, not color. One can adapt selectively to only some of the contours in a display, making only these contours temporarily invisible. For instance, a plaid comprises a vertical grating superimposed on a horizontal grating. If one first adapts to appropriate flickering vertical lines, the vertical components of the plaid disappears and it looks like a horizontal grating. Also, we simulated a Cornsweet (1970) edge, and we selectively adapted out the subjective and objective contours of a Kanisza (1976) subjective square. By temporarily removing edges, contour adaptation offers a new technique to study the role of visual edges, and it demonstrates how brightness information is concentrated in edges and propagates from them as it fills in surfaces.

  12. Shortened Intervals during Heterologous Boosting Preserve Memory CD8 T Cell Function but Compromise Longevity.

    PubMed

    Thompson, Emily A; Beura, Lalit K; Nelson, Christine E; Anderson, Kristin G; Vezys, Vaiva

    2016-04-01

    Developing vaccine strategies to generate high numbers of Ag-specific CD8 T cells may be necessary for protection against recalcitrant pathogens. Heterologous prime-boost-boost immunization has been shown to result in large quantities of functional memory CD8 T cells with protective capacities and long-term stability. Completing the serial immunization steps for heterologous prime-boost-boost can be lengthy, leaving the host vulnerable for an extensive period of time during the vaccination process. We show in this study that shortening the intervals between boosting events to 2 wk results in high numbers of functional and protective Ag-specific CD8 T cells. This protection is comparable to that achieved with long-term boosting intervals. Short-boosted Ag-specific CD8 T cells display a canonical memory T cell signature associated with long-lived memory and have identical proliferative potential to long-boosted T cells Both populations robustly respond to antigenic re-exposure. Despite this, short-boosted Ag-specific CD8 T cells continue to contract gradually over time, which correlates to metabolic differences between short- and long-boosted CD8 T cells at early memory time points. Our studies indicate that shortening the interval between boosts can yield abundant, functional Ag-specific CD8 T cells that are poised for immediate protection; however, this is at the expense of forming stable long-term memory. PMID:26903479

  13. Development of a high speed parallel hybrid boost bearing

    NASA Technical Reports Server (NTRS)

    Winn, L. W.; Eusepi, M. W.

    1973-01-01

    The analysis, design, and testing of the hybrid boost bearing are discussed. The hybrid boost bearing consists of a fluid film bearing coupled in parallel with a rolling element bearing. This coupling arrangement makes use of the inherent advantages of both the fluid film and rolling element bearing and at the same time minimizes their disadvantages and limitations. The analytical optimization studies that lead to the final fluid film bearing design are reported. The bearing consisted of a centrifugally-pressurized planar fluid film thrust bearing with oil feed through the shaft center. An analysis of the test ball bearing is also presented. The experimental determination of the hybrid bearing characteristics obtained on the basis of individual bearing component tests and a combined hybrid bearing assembly is discussed and compared to the analytically determined performance characteristics.

  14. Bifurcation behaviours of peak current controlled PFC boost converter

    NASA Astrophysics Data System (ADS)

    Ren, Hai-Peng; Liu, Ding

    2005-07-01

    Bifurcation behaviours of the peak current controlled power-factor-correction (PFC) boost converter, including fast-scale instability and low-frequency bifurcation, are investigated in this paper. Conventionally, the PFC converter is analysed in continuous conduction mode (CCM). This prevents us from recognizing the overall dynamics of the converter. It has been pointed out that the discontinuous conduction mode (DCM) can occur in the PFC boost converter, especially in the light load condition. Therefore, the DCM model is employed to analyse the PFC converter to cover the possible DCM operation. By this way, the low-frequency bifurcation diagram is derived, which makes the route from period-double bifurcation to chaos clear. The bifurcation diagrams versus the load resistance and the output capacitance also indicate the stable operation boundary of the converter, which is useful for converter design.

  15. High Temperature Boost (HTB) Power Processing Unit (PPU) Formulation Study

    NASA Technical Reports Server (NTRS)

    Chen, Yuan; Bradley, Arthur T.; Iannello, Christopher J.; Carr, Gregory A.; Mohammad, Mojarradi M.; Hunter, Don J.; DelCastillo, Linda; Stell, Christopher B.

    2013-01-01

    This technical memorandum is to summarize the Formulation Study conducted during fiscal year 2012 on the High Temperature Boost (HTB) Power Processing Unit (PPU). The effort is authorized and supported by the Game Changing Technology Division, NASA Office of the Chief Technologist. NASA center participation during the formulation includes LaRC, KSC and JPL. The Formulation Study continues into fiscal year 2013. The formulation study has focused on the power processing unit. The team has proposed a modular, power scalable, and new technology enabled High Temperature Boost (HTB) PPU, which has 5-10X improvement in PPU specific power/mass and over 30% in-space solar electric system mass saving.

  16. Externally Dispersed Interferometry for Resolution Boosting and Doppler Velocimetry

    SciTech Connect

    Erskine, D J

    2003-12-01

    Externally dispersed interferometry (EDI) is a rapidly advancing technique for wide bandwidth spectroscopy and radial velocimetry. By placing a small angle-independent interferometer near the slit of an existing spectrograph system, periodic fiducials are embedded on the recorded spectrum. The multiplication of the stellar spectrum times the sinusoidal fiducial net creates a moire pattern, which manifests high detailed spectral information heterodyned down to low spatial frequencies. The latter can more accurately survive the blurring, distortions and CCD Nyquist limitations of the spectrograph. Hence lower resolution spectrographs can be used to perform high resolution spectroscopy and radial velocimetry (under a Doppler shift the entire moir{acute e} pattern shifts in phase). A demonstration of {approx}2x resolution boosting (100,000 from 50,000) on the Lick Obs. echelle spectrograph is shown. Preliminary data indicating {approx}8x resolution boost (170,000 from 20,000) using multiple delays has been taken on a linear grating spectrograph.

  17. Boosting bonsai trees for handwritten/printed text discrimination

    NASA Astrophysics Data System (ADS)

    Ricquebourg, Yann; Raymond, Christian; Poirriez, Baptiste; Lemaitre, Aurélie; Coüasnon, Bertrand

    2013-12-01

    Boosting over decision-stumps proved its efficiency in Natural Language Processing essentially with symbolic features, and its good properties (fast, few and not critical parameters, not sensitive to over-fitting) could be of great interest in the numeric world of pixel images. In this article we investigated the use of boosting over small decision trees, in image classification processing, for the discrimination of handwritten/printed text. Then, we conducted experiments to compare it to usual SVM-based classification revealing convincing results with very close performance, but with faster predictions and behaving far less as a black-box. Those promising results tend to make use of this classifier in more complex recognition tasks like multiclass problems.

  18. Estimate of avoidance maneuver rate for HASTOL tether boost facility

    NASA Astrophysics Data System (ADS)

    Forward, Robert L.

    2002-01-01

    The Hypersonic Airplane Space Tether Orbital Launch (HASTOL) Architecture uses a hypersonic airplane (or reusable launch vehicle) to carry a payload from the surface of the Earth to 150 km altitude and a speed of Mach 17. The hypersonic airplane makes a rendezvous with the grapple at the tip of a long, rotating, orbiting space tether boost facility, which picks up the payload from the airplane. Release of the payload at the proper point in the tether rotation boosts the payload into a higher orbit, typically into a Geosynchronous Transfer Orbit (GTO), with lower orbits and Earth escape other options. The HASTOL Tether Boost Facility will have a length of 636 km. Its center of mass will be in a 604 km by 890 km equatorial orbit. It is estimated that by the time of the start of operations of the HASTOL Tether Boost facility in the year 2020, there will be 500 operational spacecraft using the same volume of space as the HASTOL facility. These operational spacecraft would likely be made inoperative by an impact with one of the lines in the multiline HASTOL Hoytether™ and should be avoided. There will also be non-operational spacecraft and large pieces of orbital debris with effective size greater than five meters in diameter that could cut a number of lines in the HASTOL Hoytether™, and should also be avoided. It is estimated, using two different methods and combining them, that the HASTOL facility will need to make avoidance maneuvers about once every four days if the 500 operational spacecraft and large pieces of orbital debris greater than 5 m in diameter, were each protected by a 2 km diameter miss distance protection sphere. If by 2020, the ability to know the positions of operational spacecraft and large pieces of orbital debris improved to allow a 600 m diameter miss distance protection sphere around each object, then the number of HASTOL facility maneuvers needed drops to one every two weeks. .

  19. The Voltage Boost Enabled by Luminescence Extraction in Solar Cells

    DOE PAGES

    Ganapati, Vidya; Steiner, Myles A.; Yablonovitch, Eli

    2016-07-01

    Over the past few years, the application of the physical principle, i.e., 'luminescence extraction,' has produced record voltages and efficiencies in photovoltaic cells. Luminescence extraction is the use of optical design, such as a back mirror or textured surfaces, to help internal photons escape out of the front surface of a solar cell. The principle of luminescence extraction is exemplified by the mantra 'a good solar cell should also be a good LED.' Basic thermodynamics says that the voltage boost should be related to concentration ratio C of a resource by ΔV = (kT/q) ln{C}. In light trapping (i.e., when the solar cell is textured and has a perfect back mirror), the concentration ratio of photons C = {4n2}; therefore, one would expect a voltage boost of ΔV = (kT/q) ln{4n2} over a solar cell with no texture and zero back reflectivity, where n is the refractive index. Nevertheless, there has been ambiguity over the voltage benefit to be expected from perfect luminescence extraction. Do we gain an open-circuit voltage boost of ΔV = (kT/q) ln{n2}, ΔV = (kT/q) ln{2 n2}, or ΔV = (kT/q) ln{4 n2}? What is responsible for this voltage ambiguity ΔV = (kT/q) ln{4}more » $${\\asymp}$$ 36 mV? Finally, we show that different results come about, depending on whether the photovoltaic cell is optically thin or thick to its internal luminescence. In realistic intermediate cases of optical thickness, the voltage boost falls in between: ln{n2} < (qΔV/kT) < ln{4n 2}.« less

  20. Fast interceptors for theater boost-phase intercept

    SciTech Connect

    Canavan, G.H.

    1993-04-01

    Boost-phase theater intercept concepts are needed for known and existing countermeasures to current systems. Fast kinetic energy interceptors could be developed from existing and improved propulsion technology and miniaturized sensors to provide that capability. High velocity interceptors with achievable acceleration could achieve the ranges needed for protection of bases and populations, addressing most theater threats. Propulsion requires development. Drag and heating are largely predictable and controllable. Fast interceptors would also have useful applications in national and global missile defense.

  1. (In)direct detection of boosted dark matter

    SciTech Connect

    Agashe, Kaustubh; Cui, Yanou; Necib, Lina; Thaler, Jesse E-mail: cuiyo@umd.edu E-mail: jthaler@mit.edu

    2014-10-01

    We initiate the study of novel thermal dark matter (DM) scenarios where present-day annihilation of DM in the galactic center produces boosted stable particles in the dark sector. These stable particles are typically a subdominant DM component, but because they are produced with a large Lorentz boost in this process, they can be detected in large volume terrestrial experiments via neutral-current-like interactions with electrons or nuclei. This novel DM signal thus combines the production mechanism associated with indirect detection experiments (i.e. galactic DM annihilation) with the detection mechanism associated with direct detection experiments (i.e. DM scattering off terrestrial targets). Such processes are generically present in multi-component DM scenarios or those with non-minimal DM stabilization symmetries. As a proof of concept, we present a model of two-component thermal relic DM, where the dominant heavy DM species has no tree-level interactions with the standard model and thus largely evades direct and indirect DM bounds. Instead, its thermal relic abundance is set by annihilation into a subdominant lighter DM species, and the latter can be detected in the boosted channel via the same annihilation process occurring today. Especially for dark sector masses in the 10 MeV–10 GeV range, the most promising signals are electron scattering events pointing toward the galactic center. These can be detected in experiments designed for neutrino physics or proton decay, in particular Super-K and its upgrade Hyper-K, as well as the PINGU/MICA extensions of IceCube. This boosted DM phenomenon highlights the distinctive signatures possible from non-minimal dark sectors.

  2. (In)direct detection of boosted dark matter

    NASA Astrophysics Data System (ADS)

    Agashe, Kaustubh; Cui, Yanou; Necib, Lina; Thaler, Jesse

    2014-10-01

    We initiate the study of novel thermal dark matter (DM) scenarios where present-day annihilation of DM in the galactic center produces boosted stable particles in the dark sector. These stable particles are typically a subdominant DM component, but because they are produced with a large Lorentz boost in this process, they can be detected in large volume terrestrial experiments via neutral-current-like interactions with electrons or nuclei. This novel DM signal thus combines the production mechanism associated with indirect detection experiments (i.e. galactic DM annihilation) with the detection mechanism associated with direct detection experiments (i.e. DM scattering off terrestrial targets). Such processes are generically present in multi-component DM scenarios or those with non-minimal DM stabilization symmetries. As a proof of concept, we present a model of two-component thermal relic DM, where the dominant heavy DM species has no tree-level interactions with the standard model and thus largely evades direct and indirect DM bounds. Instead, its thermal relic abundance is set by annihilation into a subdominant lighter DM species, and the latter can be detected in the boosted channel via the same annihilation process occurring today. Especially for dark sector masses in the 10 MeV-10 GeV range, the most promising signals are electron scattering events pointing toward the galactic center. These can be detected in experiments designed for neutrino physics or proton decay, in particular Super-K and its upgrade Hyper-K, as well as the PINGU/MICA extensions of IceCube. This boosted DM phenomenon highlights the distinctive signatures possible from non-minimal dark sectors.

  3. Poland's Education and Training: Boosting and Adapting Human Capital. OECD Economics Department Working Papers, No. 495

    ERIC Educational Resources Information Center

    O'Brien, Paul; Paczynski, Wojciech

    2006-01-01

    An effective system of education and training is important for both social and economic reasons. Its role in the Polish economy is to provide the current and future labour force with skills to facilitate both continuing productivity growth and reallocation of resources as structural adjustment proceeds. Important reforms to decentralise primary…

  4. How to Boost the Breast Tumor Bed? A Multidisciplinary Approach in Eight Steps

    SciTech Connect

    Kirova, Youlia M. Fournier-Bidoz, Nathalie; Servois, Vincent; Laki, Fatima; Pollet, Guillaume A.; Salmon, Remy; Thomas, Alexandra; Dendale, Remi; Bollet, Marc A.; Campana, Francois M.D.; Fourquet, Alain

    2008-10-01

    Purpose: To describe a new procedure for breast radiotherapy that will improve tumor bed localization and radiotherapy treatment using a multidisciplinary approach. Patients and Methods: This pilot study was conducted by departments of radiation oncology, surgery, and radiology. A new procedure has been implemented, summarized as eight steps: from pre-surgery contrast CT to surgery, tumor bed planning target volume (PTV) determination, and finally breast and tumor bed irradiation. Results: Twenty patients presenting with T1N0M0 tumors were enrolled in the study. All patients underwent lumpectomy with the placement of surgical clips in the tumor bed region. During surgery, 1 to 5 clips were placed in the lumpectomy cavity before the plastic procedure. All patients underwent pre- and postoperative CT scans in the treatment position. The two sets of images were registered with a match-point registration. All volumes were contoured and the results evaluated. The PTV included the clips region, the gross tumor volume, and the surgical scar, with an overall margin of 5-10 mm in all directions, corresponding to localization and setup uncertainties. For each patient the boost PTV was discussed and compared with our standard forward-planned PTV. Conclusions: We demonstrate the feasibility of a tumor bed localization and treatment procedure that seems adaptable to routine practice. Our study shows the advantages of a multidisciplinary approach for tumor bed localization and treatment. The use of more than 1 clip associated with pre- to postoperative CT image registration allows better definition of the PTV boost volume.

  5. Climate adaptation

    NASA Astrophysics Data System (ADS)

    Kinzig, Ann P.

    2015-03-01

    This paper is intended as a brief introduction to climate adaptation in a conference devoted otherwise to the physics of sustainable energy. Whereas mitigation involves measures to reduce the probability of a potential event, such as climate change, adaptation refers to actions that lessen the impact of climate change. Mitigation and adaptation differ in other ways as well. Adaptation does not necessarily have to be implemented immediately to be effective; it only needs to be in place before the threat arrives. Also, adaptation does not necessarily require global, coordinated action; many effective adaptation actions can be local. Some urban communities, because of land-use change and the urban heat-island effect, currently face changes similar to some expected under climate change, such as changes in water availability, heat-related morbidity, or changes in disease patterns. Concern over those impacts might motivate the implementation of measures that would also help in climate adaptation, despite skepticism among some policy makers about anthropogenic global warming. Studies of ancient civilizations in the southwestern US lends some insight into factors that may or may not be important to successful adaptation.

  6. Toothbrush Adaptations.

    ERIC Educational Resources Information Center

    Exceptional Parent, 1987

    1987-01-01

    Suggestions are presented for helping disabled individuals learn to use or adapt toothbrushes for proper dental care. A directory lists dental health instructional materials available from various organizations. (CB)

  7. Tumor bed boost radiotherapy in breast cancer. A review of current techniques.

    PubMed

    Bahadur, Yasir A; Constantinescu, Camelia T

    2012-04-01

    Various breast boost irradiation techniques were studied and compared. The most commonly used techniques are external beam radiation therapy (EBRT) (photons or electrons) and high dose rate (HDR) interstitial brachytherapy, but recent studies have also revealed the use of advanced radiotherapy techniques, such as intensity modulated radiation therapy (IMRT), intra-operative radiation therapy (IORT), tomotherapy, and protons. The purpose of this study is to systematically review the literature concerning breast boost radiotherapy techniques, and suggest evidence based guidelines for each. A search for literature was performed in the National Library of Medicine's (PubMed) database for English-language articles published from 1st January 1990 to 5th April 2011. The key words were `breast boost radiotherapy`, `breast boost irradiation`, and `breast boost irradiation AND techniques`. Randomized trials comparing the long-term results of boost irradiation techniques, balancing the local control, and cosmesis against logistic resources, and including cost-benefit analysis are further needed. PMID:22485229

  8. How citation boosts promote scientific paradigm shifts and nobel prizes.

    PubMed

    Mazloumian, Amin; Eom, Young-Ho; Helbing, Dirk; Lozano, Sergi; Fortunato, Santo

    2011-01-01

    Nobel Prizes are commonly seen to be among the most prestigious achievements of our times. Based on mining several million citations, we quantitatively analyze the processes driving paradigm shifts in science. We find that groundbreaking discoveries of Nobel Prize Laureates and other famous scientists are not only acknowledged by many citations of their landmark papers. Surprisingly, they also boost the citation rates of their previous publications. Given that innovations must outcompete the rich-gets-richer effect for scientific citations, it turns out that they can make their way only through citation cascades. A quantitative analysis reveals how and why they happen. Science appears to behave like a self-organized critical system, in which citation cascades of all sizes occur, from continuous scientific progress all the way up to scientific revolutions, which change the way we see our world. Measuring the "boosting effect" of landmark papers, our analysis reveals how new ideas and new players can make their way and finally triumph in a world dominated by established paradigms. The underlying "boost factor" is also useful to discover scientific breakthroughs and talents much earlier than through classical citation analysis, which by now has become a widespread method to measure scientific excellence, influencing scientific careers and the distribution of research funds. Our findings reveal patterns of collective social behavior, which are also interesting from an attention economics perspective. Understanding the origin of scientific authority may therefore ultimately help to explain how social influence comes about and why the value of goods depends so strongly on the attention they attract. PMID:21573229

  9. How Citation Boosts Promote Scientific Paradigm Shifts and Nobel Prizes

    PubMed Central

    Mazloumian, Amin; Eom, Young-Ho; Helbing, Dirk; Lozano, Sergi; Fortunato, Santo

    2011-01-01

    Nobel Prizes are commonly seen to be among the most prestigious achievements of our times. Based on mining several million citations, we quantitatively analyze the processes driving paradigm shifts in science. We find that groundbreaking discoveries of Nobel Prize Laureates and other famous scientists are not only acknowledged by many citations of their landmark papers. Surprisingly, they also boost the citation rates of their previous publications. Given that innovations must outcompete the rich-gets-richer effect for scientific citations, it turns out that they can make their way only through citation cascades. A quantitative analysis reveals how and why they happen. Science appears to behave like a self-organized critical system, in which citation cascades of all sizes occur, from continuous scientific progress all the way up to scientific revolutions, which change the way we see our world. Measuring the “boosting effect” of landmark papers, our analysis reveals how new ideas and new players can make their way and finally triumph in a world dominated by established paradigms. The underlying “boost factor” is also useful to discover scientific breakthroughs and talents much earlier than through classical citation analysis, which by now has become a widespread method to measure scientific excellence, influencing scientific careers and the distribution of research funds. Our findings reveal patterns of collective social behavior, which are also interesting from an attention economics perspective. Understanding the origin of scientific authority may therefore ultimately help to explain how social influence comes about and why the value of goods depends so strongly on the attention they attract. PMID:21573229

  10. How citation boosts promote scientific paradigm shifts and nobel prizes.

    PubMed

    Mazloumian, Amin; Eom, Young-Ho; Helbing, Dirk; Lozano, Sergi; Fortunato, Santo

    2011-05-04

    Nobel Prizes are commonly seen to be among the most prestigious achievements of our times. Based on mining several million citations, we quantitatively analyze the processes driving paradigm shifts in science. We find that groundbreaking discoveries of Nobel Prize Laureates and other famous scientists are not only acknowledged by many citations of their landmark papers. Surprisingly, they also boost the citation rates of their previous publications. Given that innovations must outcompete the rich-gets-richer effect for scientific citations, it turns out that they can make their way only through citation cascades. A quantitative analysis reveals how and why they happen. Science appears to behave like a self-organized critical system, in which citation cascades of all sizes occur, from continuous scientific progress all the way up to scientific revolutions, which change the way we see our world. Measuring the "boosting effect" of landmark papers, our analysis reveals how new ideas and new players can make their way and finally triumph in a world dominated by established paradigms. The underlying "boost factor" is also useful to discover scientific breakthroughs and talents much earlier than through classical citation analysis, which by now has become a widespread method to measure scientific excellence, influencing scientific careers and the distribution of research funds. Our findings reveal patterns of collective social behavior, which are also interesting from an attention economics perspective. Understanding the origin of scientific authority may therefore ultimately help to explain how social influence comes about and why the value of goods depends so strongly on the attention they attract.

  11. An Electronic Ballast Using Back-boost Converter

    NASA Astrophysics Data System (ADS)

    Yokozeki, I.; Kato, Y.; Kuratani, T.; Okamura, Y.; Ohkita, M.; Takahashi, N.

    The new circuit of the electronic ballast for a fluorescent lamp, which is based on the back-boost converter, is proposed. This circuit has the advantage further than the circuit that combined the converter for rectification with the inverter for lighting in some points. Those advantages are reduction of the number of elements and improvement in the circuit efficiency, etc. And this circuit also satisfies regulation value of IEC class C on the relative harmonic contents of input current. From experimental results, the effectiveness of the proposed circuit is shown.

  12. Cylindrical array luminescent solar concentrators: performance boosts by geometric effects.

    PubMed

    Videira, Jose J H; Bilotti, Emiliano; Chatten, Amanda J

    2016-07-11

    This paper presents an investigation of the geometric effects within a cylindrical array luminescent solar concentrator (LSC). Photon concentration of a cylindrical LSC increases linearly with cylinder length up to 2 metres. Raytrace modelling on the shading effects of circles on their neighbours demonstrates effective incident light trapping in a cylindrical LSC array at angles of incidence between 60-70 degrees. Raytrace modelling with real-world lighting conditions shows optical efficiency boosts when the suns angle of incidence is within this angle range. On certain days, 2 separate times of peak optical efficiency can be attained over the course of sunrise-solar noon. PMID:27410904

  13. Final Technical Report for the BOOST2013 Workshop. Hosted by the University of Arizona

    SciTech Connect

    Johns, Kenneth

    2015-02-20

    BOOST 2013 was the 5th International Joint Theory/Experiment Workshop on Phenomenology, Reconstruction and Searches for Boosted Objects in High Energy Hadron Collisions. It was locally organized and hosted by the Experimental High Energy Physics Group at the University of Arizona and held at Flagstaff, Arizona on August 12-16, 2013. The workshop provided a forum for theorists and experimentalists to present and discuss the latest findings related to the reconstruction of boosted objects in high energy hadron collisions and their use in searches for new physics. This report gives the outcomes of the BOOST 2013 Workshop.

  14. Jet substructures of boosted polarized hadronic top quarks

    NASA Astrophysics Data System (ADS)

    Kitadono, Yoshio; Li, Hsiang-nan

    2016-03-01

    We study jet substructures of a boosted polarized top quark, which undergoes the hadronic decay t →b u d ¯, in the perturbative QCD framework, focusing on the energy profile and the differential energy profile. These substructures are factorized into the convolution of a hard top-quark decay kernel with a bottom-quark jet function and a W -boson jet function, where the latter is further factorized into the convolution of a hard W -boson decay kernel with two light-quark jet functions. Computing the hard kernels to leading order in QCD and including the resummation effect in the jet functions, we show that the differential jet energy profile is a useful observable for differentiating the helicity of a boosted hadronic top quark: a right-handed top jet exhibits quick descent of the differential energy profile with the inner test cone radius r , which is attributed to the V -A structure of weak interaction and the dead-cone effect associated with the W -boson jet. The above helicity differentiation may help reveal the chiral structure of physics beyond the standard model at high energies.

  15. A TEG Efficiency Booster with Buck-Boost Conversion

    NASA Astrophysics Data System (ADS)

    Wu, Hongfei; Sun, Kai; Zhang, Junjun; Xing, Yan

    2013-07-01

    A thermoelectric generator (TEG) efficiency booster with buck-boost conversion and power management is proposed as a TEG battery power conditioner suitable for a wide TEG output voltage range. An inverse-coupled inductor is employed in the buck-boost converter, which is used to achieve smooth current with low ripple on both the TEG and battery sides. Furthermore, benefiting from the magnetic flux counteraction of the two windings on the coupled inductor, the core size and power losses of the filter inductor are reduced, which can achieve both high efficiency and high power density. A power management strategy is proposed for this power conditioning system, which involves maximum power point tracking (MPPT), battery voltage control, and battery current control. A control method is employed to ensure smooth switching among different working modes. A modified MPPT control algorithm with improved dynamic and steady-state characteristics is presented and applied to the TEG battery power conditioning system to maximize energy harvesting. A 500-W prototype has been built, and experimental tests carried out on it. The power efficiency of the prototype at full load is higher than 96%, and peak efficiency of 99% is attained.

  16. Hyperdynamics boost factor achievable with an ideal bias potential

    DOE PAGES

    Huang, Chen; Perez, Danny; Voter, Arthur F.

    2015-08-20

    Hyperdynamics is a powerful method to significantly extend the time scales amenable to molecular dynamics simulation of infrequent events. One outstanding challenge, however, is the development of the so-called bias potential required by the method. In this work, we design a bias potential using information about all minimum energy pathways (MEPs) out of the current state. While this approach is not suitable for use in an actual hyperdynamics simulation, because the pathways are generally not known in advance, it allows us to show that it is possible to come very close to the theoretical boost limit of hyperdynamics while maintainingmore » high accuracy. We demonstrate this by applying this MEP-based hyperdynamics (MEP-HD) to metallic surface diffusion systems. In most cases, MEP-HD gives boost factors that are orders of magnitude larger than the best existing bias potential, indicating that further development of hyperdynamics bias potentials could have a significant payoff. Lastly, we discuss potential practical uses of MEP-HD, including the possibility of developing MEP-HD into a true hyperdynamics.« less

  17. Hyperdynamics boost factor achievable with an ideal bias potential

    NASA Astrophysics Data System (ADS)

    Huang, Chen; Perez, Danny; Voter, Arthur F.

    2015-08-01

    Hyperdynamics is a powerful method to significantly extend the time scales amenable to molecular dynamics simulation of infrequent events. One outstanding challenge, however, is the development of the so-called bias potential required by the method. In this work, we design a bias potential using information about all minimum energy pathways (MEPs) out of the current state. While this approach is not suitable for use in an actual hyperdynamics simulation, because the pathways are generally not known in advance, it allows us to show that it is possible to come very close to the theoretical boost limit of hyperdynamics while maintaining high accuracy. We demonstrate this by applying this MEP-based hyperdynamics (MEP-HD) to metallic surface diffusion systems. In most cases, MEP-HD gives boost factors that are orders of magnitude larger than the best existing bias potential, indicating that further development of hyperdynamics bias potentials could have a significant payoff. Finally, we discuss potential practical uses of MEP-HD, including the possibility of developing MEP-HD into a true hyperdynamics.

  18. Hyperdynamics boost factor achievable with an ideal bias potential

    SciTech Connect

    Huang, Chen; Perez, Danny; Voter, Arthur F.

    2015-08-20

    Hyperdynamics is a powerful method to significantly extend the time scales amenable to molecular dynamics simulation of infrequent events. One outstanding challenge, however, is the development of the so-called bias potential required by the method. In this work, we design a bias potential using information about all minimum energy pathways (MEPs) out of the current state. While this approach is not suitable for use in an actual hyperdynamics simulation, because the pathways are generally not known in advance, it allows us to show that it is possible to come very close to the theoretical boost limit of hyperdynamics while maintaining high accuracy. We demonstrate this by applying this MEP-based hyperdynamics (MEP-HD) to metallic surface diffusion systems. In most cases, MEP-HD gives boost factors that are orders of magnitude larger than the best existing bias potential, indicating that further development of hyperdynamics bias potentials could have a significant payoff. Lastly, we discuss potential practical uses of MEP-HD, including the possibility of developing MEP-HD into a true hyperdynamics.

  19. Boosting the Light: X-ray Physics in Confinement

    ScienceCinema

    Rhisberger, Ralf [HASYLAB/ DESY

    2016-07-12

    Remarkable effects are observed if light is confined to dimensions comparable to the wavelength of the light. The lifetime of atomic resonances excited by the radiation is strongly reduced in photonic traps, such as cavities or waveguides. Moreover, one observes an anomalous boost of the intensity scattered from the resonant atoms. These phenomena results from the strong enhancement of the photonic density of states in such geometries. Many of these effects are currently being explored in the regime of vsible light due to their relevance for optical information processing. It is thus appealing to study these phenomena also for much shorter wavelengths. This talk illuminates recent experiments where synchrotron x-rays were trapped in planar waveguides to resonantly excite atomos ([57]Fe nuclei_ embedded in them. In fact, one observes that the radiative decay of these excited atoms is strongly accelerated. The temporal acceleration of the decay goes along with a strong boost of the radiation coherently scattered from the confined atmos. This can be exploited to obtain a high signal-to-noise ratio from tiny quantities of material, leading to manifold applications in the investigation of nanostructured materials. One application is the use of ultrathin probe layers to image the internal structure of magnetic layer systems.

  20. Angular observables for spin discrimination in boosted diboson final states

    NASA Astrophysics Data System (ADS)

    Buschmann, Malte; Yu, Felix

    2016-09-01

    We investigate the prospects for spin determination of a heavy diboson resonance using angular observables. Focusing in particular on boosted fully hadronic final states, we detail both the differences in signal efficiencies and distortions of differential distributions resulting from various jet substructure techniques. We treat the 2 TeV diboson excess as a case study, but our results are generally applicable to any future discovery in the diboson channel. Scrutinizing ATLAS and CMS analyses at 8 TeV and 13 TeV, we find that the specific cuts employed in these analyses have a tremendous impact on the discrimination power between different signal hypotheses. We discuss modified cuts that can offer a significant boost to spin sensitivity in a post-discovery era. Even without altered cuts, we show that CMS, and partly also ATLAS, will be able to distinguish between spin 0, 1, or 2 new physics diboson resonances at the 2 σ level with 30 fb-1 of 13 TeV data, for our 2 TeV case study.

  1. IHPRPT Phase I Solid Boost Demonstrator: A Success Story

    NASA Astrophysics Data System (ADS)

    Glaittli, Steven R.

    2001-06-01

    The integrated High-Payoff Rocket Propulsion Technology or IHPRPT program seeks to double the launch capability of the United States by the year 2010. The program is organized into three phases, with a technology demonstrator at the end of each phase. The IHPRPT Phase I Solid Boost Demonstrator Program is presented. Materials and processing technologies developed under the IHPRPT program and on other contracted technology and privately funded programs were combined into one full-scale booster demonstrator culminating six years of new technology work. New materials and processes were used in all components of the demonstration motor to achieve the cost and performance goals identified for the Phase I Boost & Orbit Transfer Propulsion mission area in the IHPRPT program. New materials utilized in the motor included low cost high performance carbon fibers in the composite case energetic ingredients in the propellant. net molded structural parts in the nozzle. and an all-new electromechanical Thrust Vector Actuation (TVA) system. The demonstrator was successfully static tested on 16 November 2000 The static test has been heralded as a success by government and industry observers alike.

  2. Adaptive Development

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The goal of this research is to develop and demonstrate innovative adaptive seal technologies that can lead to dramatic improvements in engine performance, life, range, and emissions, and enhance operability for next generation gas turbine engines. This work is concentrated on the development of self-adaptive clearance control systems for gas turbine engines. Researchers have targeted the high-pressure turbine (HPT) blade tip seal location for following reasons: Current active clearance control (ACC) systems (e.g., thermal case-cooling schemes) cannot respond to blade tip clearance changes due to mechanical, thermal, and aerodynamic loads. As such they are prone to wear due to the required tight running clearances during operation. Blade tip seal wear (increased clearances) reduces engine efficiency, performance, and service life. Adaptive sealing technology research has inherent impact on all envisioned 21st century propulsion systems (e.g. distributed vectored, hybrid and electric drive propulsion concepts).

  3. Adaptive management

    USGS Publications Warehouse

    Allen, Craig R.; Garmestani, Ahjond S.

    2015-01-01

    Adaptive management is an approach to natural resource management that emphasizes learning through management where knowledge is incomplete, and when, despite inherent uncertainty, managers and policymakers must act. Unlike a traditional trial and error approach, adaptive management has explicit structure, including a careful elucidation of goals, identification of alternative management objectives and hypotheses of causation, and procedures for the collection of data followed by evaluation and reiteration. The process is iterative, and serves to reduce uncertainty, build knowledge and improve management over time in a goal-oriented and structured process.

  4. Junctate boosts phagocytosis by recruiting endoplasmic reticulum Ca2+ stores near phagosomes.

    PubMed

    Guido, Daniele; Demaurex, Nicolas; Nunes, Paula

    2015-11-15

    Local intracellular Ca(2+) elevations increase the efficiency of phagocytosis, a process that is essential for innate and adaptive immunity. These local Ca(2+) elevations are generated in part by the store-operated Ca(2+) entry (SOCE) sensor STIM1, which recruits endoplasmic reticulum (ER) cisternae to phagosomes and opens phagosomal Ca(2+) channels at ER-phagosome junctions. However, residual ER-phagosome contacts and periphagosomal Ca(2+) hotspots remain in Stim1(-/-) cells. Here, we tested whether junctate (also called ASPH isoform 8), a molecule that targets STIM1 to ER-plasma-membrane contacts upon Ca(2+)-store depletion, cooperates with STIM1 at phagosome junctions. Junctate expression in Stim1(-/-) and Stim1(-/-); Stim2(-/-) phagocytic fibroblasts increased phagocytosis and periphagosomal Ca(2+) elevations, yet with only a minimal impact on global SOCE. These Ca(2+) hotspots were only marginally reduced by the SOCE channel blocker lanthanum chloride (La(3+)) but were abrogated by inositol trisphosphate receptor inhibitors 2-APB and xestospongin-C, revealing that unlike STIM1-mediated hotspots, junctate-mediated Ca(2+) originates predominantly from periphagosomal Ca(2+) stores. Accordingly, junctate accumulates near phagosomes and elongates ER-phagosome junctions in Stim1(-/-) cells. Thus, junctate mediates an alternative mechanism for generating localized Ca(2+) elevations within cells, promoting Ca(2+) release from internal stores recruited to phagosomes, thereby boosting phagocytosis.

  5. C4 photosynthesis boosts growth by altering physiology, allocation and size.

    PubMed

    Atkinson, Rebecca R L; Mockford, Emily J; Bennett, Christopher; Christin, Pascal-Antoine; Spriggs, Elizabeth L; Freckleton, Robert P; Thompson, Ken; Rees, Mark; Osborne, Colin P

    2016-01-01

    C4 photosynthesis is a complex set of leaf anatomical and biochemical adaptations that have evolved more than 60 times to boost carbon uptake compared with the ancestral C3 photosynthetic type(1-3). Although C4 photosynthesis has the potential to drive faster growth rates(4,5), experiments directly comparing C3 and C4 plants have not shown consistent effects(1,6,7). This is problematic because differential growth is a crucial element of ecological theory(8,9) explaining C4 savannah responses to global change(10,11), and research to increase C3 crop productivity by introducing C4 photosynthesis(12). Here, we resolve this long-standing issue by comparing growth across 382 grass species, accounting for ecological diversity and evolutionary history. C4 photosynthesis causes a 19-88% daily growth enhancement. Unexpectedly, during the critical seedling establishment stage, this enhancement is driven largely by a high ratio of leaf area to mass, rather than fast growth per unit leaf area. C4 leaves have less dense tissues, allowing more leaves to be produced for the same carbon cost. Consequently, C4 plants invest more in roots than C3 species. Our data demonstrate a general suite of functional trait divergences between C3 and C4 species, which simultaneously drive faster growth and greater investment in water and nutrient acquisition, with important ecological and agronomic implications. PMID:27243645

  6. Adaptive Thresholds

    SciTech Connect

    Bremer, P. -T.

    2014-08-26

    ADAPT is a topological analysis code that allow to compute local threshold, in particular relevance based thresholds for features defined in scalar fields. The initial target application is vortex detection but the software is more generally applicable to all threshold based feature definitions.

  7. AlignerBoost: A Generalized Software Toolkit for Boosting Next-Gen Sequencing Mapping Accuracy Using a Bayesian-Based Mapping Quality Framework

    PubMed Central

    Zheng, Qi; Grice, Elizabeth A.

    2016-01-01

    Accurate mapping of next-generation sequencing (NGS) reads to reference genomes is crucial for almost all NGS applications and downstream analyses. Various repetitive elements in human and other higher eukaryotic genomes contribute in large part to ambiguously (non-uniquely) mapped reads. Most available NGS aligners attempt to address this by either removing all non-uniquely mapping reads, or reporting one random or "best" hit based on simple heuristics. Accurate estimation of the mapping quality of NGS reads is therefore critical albeit completely lacking at present. Here we developed a generalized software toolkit "AlignerBoost", which utilizes a Bayesian-based framework to accurately estimate mapping quality of ambiguously mapped NGS reads. We tested AlignerBoost with both simulated and real DNA-seq and RNA-seq datasets at various thresholds. In most cases, but especially for reads falling within repetitive regions, AlignerBoost dramatically increases the mapping precision of modern NGS aligners without significantly compromising the sensitivity even without mapping quality filters. When using higher mapping quality cutoffs, AlignerBoost achieves a much lower false mapping rate while exhibiting comparable or higher sensitivity compared to the aligner default modes, therefore significantly boosting the detection power of NGS aligners even using extreme thresholds. AlignerBoost is also SNP-aware, and higher quality alignments can be achieved if provided with known SNPs. AlignerBoost’s algorithm is computationally efficient, and can process one million alignments within 30 seconds on a typical desktop computer. AlignerBoost is implemented as a uniform Java application and is freely available at https://github.com/Grice-Lab/AlignerBoost. PMID:27706155

  8. Enhanced algorithm performance for land cover classification from remotely sensed data using bagging and boosting

    USGS Publications Warehouse

    Chan, J.C.-W.; Huang, C.; DeFries, R.

    2001-01-01

    Two ensemble methods, bagging and boosting, were investigated for improving algorithm performance. Our results confirmed the theoretical explanation [1] that bagging improves unstable, but not stable, learning algorithms. While boosting enhanced accuracy of a weak learner, its behavior is subject to the characteristics of each learning algorithm.

  9. Breast Conserving Treatment for Breast Cancer: Dosimetric Comparison of Sequential versus Simultaneous Integrated Photon Boost

    PubMed Central

    Reynders, Truus; Heuninckx, Karina; Verellen, Dirk; Storme, Guy; De Ridder, Mark

    2014-01-01

    Background. Breast conserving surgery followed by whole breast irradiation is widely accepted as standard of care for early breast cancer. Addition of a boost dose to the initial tumor area further reduces local recurrences. We investigated the dosimetric benefits of a simultaneously integrated boost (SIB) compared to a sequential boost to hypofractionate the boost volume, while maintaining normofractionation on the breast. Methods. For 10 patients 4 treatment plans were deployed, 1 with a sequential photon boost, and 3 with different SIB techniques: on a conventional linear accelerator, helical TomoTherapy, and static TomoDirect. Dosimetric comparison was performed. Results. PTV-coverage was good in all techniques. Conformity was better with all SIB techniques compared to sequential boost (P = 0.0001). There was less dose spilling to the ipsilateral breast outside the PTVboost (P = 0.04). The dose to the organs at risk (OAR) was not influenced by SIB compared to sequential boost. Helical TomoTherapy showed a higher mean dose to the contralateral breast, but less than 5 Gy for each patient. Conclusions. SIB showed less dose spilling within the breast and equal dose to OAR compared to sequential boost. Both helical TomoTherapy and the conventional technique delivered acceptable dosimetry. SIB seems a safe alternative and can be implemented in clinical routine. PMID:25162031

  10. Boost Your High: Cigarette Smoking to Enhance Alcohol and Drug Effects among Southeast Asian American Youth.

    PubMed

    Lipperman-Kreda, Sharon; Lee, Juliet P

    2011-01-01

    The current study examined: 1) whether using cigarettes to enhance the effects of other drugs (here referred to as "boosting") is a unique practice related to blunts (i.e., small cheap cigars hollowed out and filled with cannabis) or marijuana use only; 2) the prevalence of boosting among drug-using young people; and 3) the relationship between boosting and other drug-related risk behaviors. We present data collected from 89 Southeast Asian American youth and young adults in Northern California (35 females). 72% respondents reported any lifetime boosting. Controlling for gender, results of linear regression analyses show a significant positive relationship between frequency of boosting to enhance alcohol high and number of drinks per occasion. Boosting was also found to be associated with use of blunts but not other forms of marijuana and with the number of blunts on a typical day. The findings indicate that boosting may be common among drug-using Southeast Asian youths. These findings also indicate a need for further research on boosting as an aspect of cigarette uptake and maintenance among drug- and alcohol-involved youths.

  11. 14 CFR 27.695 - Power boost and power-operated control system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... mechanical system. The power portion includes the power source (such as hydraulic pumps), and such items as... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... flight and landing in the event of— (1) Any single failure in the power portion of the system;......

  12. Writing about testing worries boosts exam performance in the classroom.

    PubMed

    Ramirez, Gerardo; Beilock, Sian L

    2011-01-14

    Two laboratory and two randomized field experiments tested a psychological intervention designed to improve students' scores on high-stakes exams and to increase our understanding of why pressure-filled exam situations undermine some students' performance. We expected that sitting for an important exam leads to worries about the situation and its consequences that undermine test performance. We tested whether having students write down their thoughts about an upcoming test could improve test performance. The intervention, a brief expressive writing assignment that occurred immediately before taking an important test, significantly improved students' exam scores, especially for students habitually anxious about test taking. Simply writing about one's worries before a high-stakes exam can boost test scores. PMID:21233387

  13. Revamp of Ukraine VCM plant will boost capacity, reduce emissions

    SciTech Connect

    1996-05-13

    Oriana Concern (formerly P.O. Chlorvinyl) is revamping its 250,000 metric ton/year (mty) vinyl chloride monomer (VCM) plant at Kalusch, Ukraine. At the core of the project area new ethylene dichloride (EDC) cracking furnace and direct chlorination unit, and revamp of an oxychlorination unit to use oxygen rather than air. The plant expansion and modernization will boost capacity to 370,000 mty. New facilities for by-product recycling and recovery, waste water treatment, and emissions reduction will improve the plant`s environmental performance. This paper shows expected feedstock and utility consumption for VCM production. Techmashimport and P.O. Chlorvinyl commissioned the Kalusch plant in 1975. The plant was built by Uhde GmbH, Dortmund, Germany. The paper also provides a schematic of the Hoechst/Uhde VCM process being used for the plant revamp. The diagram is divided into processing sections.

  14. Prediction and control of limit cycling motions in boosting rockets

    NASA Astrophysics Data System (ADS)

    Newman, Brett

    An investigation concerning the prediction and control of observed limit cycling behavior in a boosting rocket is considered. The suspected source of the nonlinear behavior is the presence of Coulomb friction in the nozzle pivot mechanism. A classical sinusoidal describing function analysis is used to accurately recreate and predict the observed oscillatory characteristic. In so doing, insight is offered into the limit cycling mechanism and confidence is gained in the closed-loop system design. Nonlinear simulation results are further used to support and verify the results obtained from describing function theory. Insight into the limit cycling behavior is, in turn, used to adjust control system parameters in order to passively control the oscillatory tendencies. Tradeoffs with the guidance and control system stability/performance are also noted. Finally, active control of the limit cycling behavior, using a novel feedback algorithm to adjust the inherent nozzle sticking-unsticking characteristics, is considered.

  15. An update on Shankhpushpi, a cognition-boosting Ayurvedic medicine.

    PubMed

    Sethiya, Neeraj Kumar; Nahata, Alok; Mishra, Sri Hari; Dixit, Vinod Kumar

    2009-11-01

    Shankhpushpi is an Ayurvedic drug used for its action on the central nervous system, especially for boosting memory and improving intellect. Quantum of information gained from Ayurvedic and other Sanskrit literature revealed the existence of four different plant species under the name of Shankhpushpi, which is used in various Ayurvedic prescriptions described in ancient texts, singly or in combination with other herbs. The sources comprise of entire herbs with following botanicals viz., Convulvulus pluricaulis Choisy. (Convulvulaceae), Evolvulus alsinoides Linn. (Convulvulaceae), Clitoria ternatea Linn. (Papilionaceae) and Canscora decussata Schult. (Gentianaceae). A review on the available scientific information in terms of pharmacognostical characteristics, chemical constituents, pharmacological activities, preclinical and clinical applications of controversial sources of Shankhpushpi is prepared with a view to review scientific work undertaken on Shankhpushpi. It may provide parameters of differentiation and permit appreciation of variability of drug action by use of different botanical sources. PMID:19912732

  16. Defined three-dimensional microenvironments boost induction of pluripotency

    NASA Astrophysics Data System (ADS)

    Caiazzo, Massimiliano; Okawa, Yuya; Ranga, Adrian; Piersigilli, Alessandra; Tabata, Yoji; Lutolf, Matthias P.

    2016-03-01

    Since the discovery of induced pluripotent stem cells (iPSCs), numerous approaches have been explored to improve the original protocol, which is based on a two-dimensional (2D) cell-culture system. Surprisingly, nothing is known about the effect of a more biologically faithful 3D environment on somatic-cell reprogramming. Here, we report a systematic analysis of how reprogramming of somatic cells occurs within engineered 3D extracellular matrices. By modulating microenvironmental stiffness, degradability and biochemical composition, we have identified a previously unknown role for biophysical effectors in the promotion of iPSC generation. We find that the physical cell confinement imposed by the 3D microenvironment boosts reprogramming through an accelerated mesenchymal-to-epithelial transition and increased epigenetic remodelling. We conclude that 3D microenvironmental signals act synergistically with reprogramming transcription factors to increase somatic plasticity.

  17. Boosting thermoelectric efficiency using time-dependent control.

    PubMed

    Zhou, Hangbo; Thingna, Juzar; Hänggi, Peter; Wang, Jian-Sheng; Li, Baowen

    2015-01-01

    Thermoelectric efficiency is defined as the ratio of power delivered to the load of a device to the rate of heat flow from the source. Till date, it has been studied in presence of thermodynamic constraints set by the Onsager reciprocal relation and the second law of thermodynamics that severely bottleneck the thermoelectric efficiency. In this study, we propose a pathway to bypass these constraints using a time-dependent control and present a theoretical framework to study dynamic thermoelectric transport in the far from equilibrium regime. The presence of a control yields the sought after substantial efficiency enhancement and importantly a significant amount of power supplied by the control is utilised to convert the wasted-heat energy into useful-electric energy. Our findings are robust against nonlinear interactions and suggest that external time-dependent forcing, which can be incorporated with existing devices, provides a beneficial scheme to boost thermoelectric efficiency.

  18. Emerging applications for the Peacekeeper Post Boost Vehicle

    NASA Astrophysics Data System (ADS)

    Blake, Jack

    1992-07-01

    The use of the Peacekeeper Post Boost Vehicle (PBV) is considered for applications beyond its original use as stage IV of the ICBM system. The PBV is described in the context of the Peacekeeper mission, and the axial engine and attitude-control engines are illustrated. The capability of the PBV is found to make the engine appropriate for use as a liquid-plume generator for the Space Pallet Satellite Experiment. The PBV could also be used as a system basis for transporting large payloads into LEO, and a PBV-based platform could remain in orbit to serve as an earth/payload communication link. The PBV offers technologies and capabilities required for such missions as a plume generator, space-experiment module, or as a transfer vehicle for Space Station logistics and resupply.

  19. Writing about testing worries boosts exam performance in the classroom.

    PubMed

    Ramirez, Gerardo; Beilock, Sian L

    2011-01-14

    Two laboratory and two randomized field experiments tested a psychological intervention designed to improve students' scores on high-stakes exams and to increase our understanding of why pressure-filled exam situations undermine some students' performance. We expected that sitting for an important exam leads to worries about the situation and its consequences that undermine test performance. We tested whether having students write down their thoughts about an upcoming test could improve test performance. The intervention, a brief expressive writing assignment that occurred immediately before taking an important test, significantly improved students' exam scores, especially for students habitually anxious about test taking. Simply writing about one's worries before a high-stakes exam can boost test scores.

  20. Traction drive for cryogenic boost pump. [hydrogen oxygen rocket engines

    NASA Technical Reports Server (NTRS)

    Meyer, S.; Connelly, R. E.

    1981-01-01

    Two versions of a Nasvytis multiroller traction drive were tested in liquid oxygen for possible application as cryogenic boost pump speed reduction drives for advanced hydrogen-oxygen rocket engines. The roller drive, with a 10.8:1 reduction ratio, was successfully run at up to 70,000 rpm input speed and up to 14.9 kW (20 hp) input power level. Three drive assemblies were tested for a total of about three hours of which approximately one hour was at nominal full speed and full power conditions. Peak efficiency of 60 percent was determined. There was no evidence of slippage between rollers for any of the conditions tested. The ball drive, a version using balls instead of one row of rollers, and having a 3.25:1 reduction ratio, failed to perform satisfactorily.

  1. Boosting thermoelectric efficiency using time-dependent control.

    PubMed

    Zhou, Hangbo; Thingna, Juzar; Hänggi, Peter; Wang, Jian-Sheng; Li, Baowen

    2015-01-01

    Thermoelectric efficiency is defined as the ratio of power delivered to the load of a device to the rate of heat flow from the source. Till date, it has been studied in presence of thermodynamic constraints set by the Onsager reciprocal relation and the second law of thermodynamics that severely bottleneck the thermoelectric efficiency. In this study, we propose a pathway to bypass these constraints using a time-dependent control and present a theoretical framework to study dynamic thermoelectric transport in the far from equilibrium regime. The presence of a control yields the sought after substantial efficiency enhancement and importantly a significant amount of power supplied by the control is utilised to convert the wasted-heat energy into useful-electric energy. Our findings are robust against nonlinear interactions and suggest that external time-dependent forcing, which can be incorporated with existing devices, provides a beneficial scheme to boost thermoelectric efficiency. PMID:26464021

  2. Usefulness of effective field theory for boosted Higgs production

    SciTech Connect

    Dawson, S.; Lewis, I. M.; Zeng, Mao

    2015-04-07

    The Higgs + jet channel at the LHC is sensitive to the effects of new physics both in the total rate and in the transverse momentum distribution at high pT. We examine the production process using an effective field theory (EFT) language and discussing the possibility of determining the nature of the underlying high-scale physics from boosted Higgs production. The effects of heavy color triplet scalars and top partner fermions with TeV scale masses are considered as examples and Higgs-gluon couplings of dimension-5 and dimension-7 are included in the EFT. As a byproduct of our study, we examine the region of validity of the EFT. Dimension-7 contributions in realistic new physics models give effects in the high pT tail of the Higgs signal which are so tiny that they are likely to be unobservable.

  3. Boosting thermoelectric efficiency using time-dependent control

    PubMed Central

    Zhou, Hangbo; Thingna, Juzar; Hänggi, Peter; Wang, Jian-Sheng; Li, Baowen

    2015-01-01

    Thermoelectric efficiency is defined as the ratio of power delivered to the load of a device to the rate of heat flow from the source. Till date, it has been studied in presence of thermodynamic constraints set by the Onsager reciprocal relation and the second law of thermodynamics that severely bottleneck the thermoelectric efficiency. In this study, we propose a pathway to bypass these constraints using a time-dependent control and present a theoretical framework to study dynamic thermoelectric transport in the far from equilibrium regime. The presence of a control yields the sought after substantial efficiency enhancement and importantly a significant amount of power supplied by the control is utilised to convert the wasted-heat energy into useful-electric energy. Our findings are robust against nonlinear interactions and suggest that external time-dependent forcing, which can be incorporated with existing devices, provides a beneficial scheme to boost thermoelectric efficiency. PMID:26464021

  4. WIMPonium and boost factors for indirect dark matter detection

    NASA Astrophysics Data System (ADS)

    March-Russell, John; West, Stephen M.

    2009-06-01

    We argue that WIMP dark matter can annihilate via long-lived “WIMPonium” bound states in reasonable particle physics models of dark matter (DM). WIMPonium bound states can occur at or near threshold leading to substantial enhancements in the DM annihilation rate, closely related to the Sommerfeld effect. Large “boost factor” amplifications in the annihilation rate can thus occur without large density enhancements, possibly preferring colder less dense objects such as dwarf galaxies as locations for indirect DM searches. The radiative capture to and transitions among the WIMPonium states generically lead to a rich energy spectrum of annihilation products, with many distinct lines possible in the case of 2-body decays to γγ or γZ final states. The existence of multiple radiative capture modes further enhances the total annihilation rate, and the detection of the lines would give direct over-determined information on the nature and self-interactions of the DM particles.

  5. Measuring Intuition: Nonconscious Emotional Information Boosts Decision Accuracy and Confidence.

    PubMed

    Lufityanto, Galang; Donkin, Chris; Pearson, Joel

    2016-05-01

    The long-held popular notion of intuition has garnered much attention both academically and popularly. Although most people agree that there is such a phenomenon as intuition, involving emotionally charged, rapid, unconscious processes, little compelling evidence supports this notion. Here, we introduce a technique in which subliminal emotional information is presented to subjects while they make fully conscious sensory decisions. Our behavioral and physiological data, along with evidence-accumulator models, show that nonconscious emotional information can boost accuracy and confidence in a concurrent emotion-free decision task, while also speeding up response times. Moreover, these effects were contingent on the specific predictive arrangement of the nonconscious emotional valence and motion direction in the decisional stimulus. A model that simultaneously accumulates evidence from both physiological skin conductance and conscious decisional information provides an accurate description of the data. These findings support the notion that nonconscious emotions can bias concurrent nonemotional behavior-a process of intuition.

  6. Metabolic engineering of resveratrol and other longevity boosting compounds.

    PubMed

    Wang, Yechun; Chen, Hui; Yu, Oliver

    2010-01-01

    Resveratrol, a compound commonly found in red wine, has attracted many attentions recently. It is a diphenolic natural product accumulated in grapes and a few other species under stress conditions. It possesses a special ability to increase the life span of eukaryotic organisms, ranging from yeast, to fruit fly, to obese mouse. The demand for resveratrol as a food and nutrition supplement has increased significantly in recent years. Extensive work has been carried out to increase the production of resveratrol in plants and microbes. In this review, we will discuss the biosynthetic pathway of resveratrol and engineering methods to heterologously express the pathway in various organisms. We will outline the shortcuts and limitations of common engineering efforts. We will also discuss briefly the features and engineering challenges of other longevity boosting compounds. PMID:20848556

  7. Boosting thermoelectric efficiency using time-dependent control

    NASA Astrophysics Data System (ADS)

    Zhou, Hangbo; Thingna, Juzar; Hänggi, Peter; Wang, Jian-Sheng; Li, Baowen

    2015-10-01

    Thermoelectric efficiency is defined as the ratio of power delivered to the load of a device to the rate of heat flow from the source. Till date, it has been studied in presence of thermodynamic constraints set by the Onsager reciprocal relation and the second law of thermodynamics that severely bottleneck the thermoelectric efficiency. In this study, we propose a pathway to bypass these constraints using a time-dependent control and present a theoretical framework to study dynamic thermoelectric transport in the far from equilibrium regime. The presence of a control yields the sought after substantial efficiency enhancement and importantly a significant amount of power supplied by the control is utilised to convert the wasted-heat energy into useful-electric energy. Our findings are robust against nonlinear interactions and suggest that external time-dependent forcing, which can be incorporated with existing devices, provides a beneficial scheme to boost thermoelectric efficiency.

  8. Metabolic engineering of resveratrol and other longevity boosting compounds.

    SciTech Connect

    Wang, Y; Chen, H; Yu, O

    2010-09-16

    Resveratrol, a compound commonly found in red wine, has attracted many attentions recently. It is a diphenolic natural product accumulated in grapes and a few other species under stress conditions. It possesses a special ability to increase the life span of eukaryotic organisms, ranging from yeast, to fruit fly, to obese mouse. The demand for resveratrol as a food and nutrition supplement has increased significantly in recent years. Extensive work has been carried out to increase the production of resveratrol in plants and microbes. In this review, we will discuss the biosynthetic pathway of resveratrol and engineering methods to heterologously express the pathway in various organisms. We will outline the shortcuts and limitations of common engineering efforts. We will also discuss briefly the features and engineering challenges of other longevity boosting compounds.

  9. Syntactic priming during sentence comprehension: evidence for the lexical boost.

    PubMed

    Traxler, Matthew J; Tooley, Kristen M; Pickering, Martin J

    2014-07-01

    Syntactic priming occurs when structural information from one sentence influences processing of a subsequently encountered sentence (Bock, 1986; Ledoux et al., 2007). This article reports 2 eye-tracking experiments investigating the effects of a prime sentence on the processing of a target sentence that shared aspects of syntactic form. The experiments were designed to determine the degree to which lexical overlap between prime and target sentences produced larger effects, comparable to the widely observed "lexical boost" in production experiments (Pickering & Branigan, 1998; Pickering & Ferreira, 2008). The current experiments showed that priming effects during online comprehension were in fact larger when a verb was repeated across the prime and target sentences (see also Tooley et al., 2009). The finding of larger priming effects with lexical repetition supports accounts under which syntactic form representations are connected to individual lexical items (e.g., Tomasello, 2003; Vosse & Kempen, 2000, 2009).

  10. A mechatronic power boosting design for piezoelectric generators

    SciTech Connect

    Liu, Haili; Liang, Junrui Ge, Cong

    2015-10-05

    It was shown that the piezoelectric power generation can be boosted by using the synchronized switch power conditioning circuits. This letter reports a self-powered and self-sensing mechatronic design in substitute of the auxiliary electronics towards a compact and universal synchronized switch solution. The design criteria are derived based on the conceptual waveforms and a two-degree-of-freedom analytical model. Experimental result shows that, compared to the standard bridge rectifier interface, the mechatronic design leads to an extra 111% increase of generated power from the prototyped piezoelectric generator under the same deflection magnitude excitation. The proposed design has introduced a valuable physical insight of electromechanical synergy towards the improvement of piezoelectric power generation.

  11. Boosting magnetic reconnection by viscosity and thermal conduction

    NASA Astrophysics Data System (ADS)

    Minoshima, Takashi; Miyoshi, Takahiro; Imada, Shinsuke

    2016-07-01

    Nonlinear evolution of magnetic reconnection is investigated by means of magnetohydrodynamic simulations including uniform resistivity, uniform viscosity, and anisotropic thermal conduction. When viscosity exceeds resistivity (the magnetic Prandtl number P r m > 1 ), the viscous dissipation dominates outflow dynamics and leads to the decrease in the plasma density inside a current sheet. The low-density current sheet supports the excitation of the vortex. The thickness of the vortex is broader than that of the current for P r m > 1 . The broader vortex flow more efficiently carries the upstream magnetic flux toward the reconnection region, and consequently, boosts the reconnection. The reconnection rate increases with viscosity provided that thermal conduction is fast enough to take away the thermal energy increased by the viscous dissipation (the fluid Prandtl number Pr < 1). The result suggests the need to control the Prandtl numbers for the reconnection against the conventional resistive model.

  12. A mechatronic power boosting design for piezoelectric generators

    NASA Astrophysics Data System (ADS)

    Liu, Haili; Liang, Junrui; Ge, Cong

    2015-10-01

    It was shown that the piezoelectric power generation can be boosted by using the synchronized switch power conditioning circuits. This letter reports a self-powered and self-sensing mechatronic design in substitute of the auxiliary electronics towards a compact and universal synchronized switch solution. The design criteria are derived based on the conceptual waveforms and a two-degree-of-freedom analytical model. Experimental result shows that, compared to the standard bridge rectifier interface, the mechatronic design leads to an extra 111% increase of generated power from the prototyped piezoelectric generator under the same deflection magnitude excitation. The proposed design has introduced a valuable physical insight of electromechanical synergy towards the improvement of piezoelectric power generation.

  13. Connector adapter

    NASA Technical Reports Server (NTRS)

    Hacker, Scott C. (Inventor); Dean, Richard J. (Inventor); Burge, Scott W. (Inventor); Dartez, Toby W. (Inventor)

    2007-01-01

    An adapter for installing a connector to a terminal post, wherein the connector is attached to a cable, is presented. In an embodiment, the adapter is comprised of an elongated collet member having a longitudinal axis comprised of a first collet member end, a second collet member end, an outer collet member surface, and an inner collet member surface. The inner collet member surface at the first collet member end is used to engage the connector. The outer collet member surface at the first collet member end is tapered for a predetermined first length at a predetermined taper angle. The collet includes a longitudinal slot that extends along the longitudinal axis initiating at the first collet member end for a predetermined second length. The first collet member end is formed of a predetermined number of sections segregated by a predetermined number of channels and the longitudinal slot.

  14. Adaptive VFH

    NASA Astrophysics Data System (ADS)

    Odriozola, Iñigo; Lazkano, Elena; Sierra, Basi

    2011-10-01

    This paper investigates the improvement of the Vector Field Histogram (VFH) local planning algorithm for mobile robot systems. The Adaptive Vector Field Histogram (AVFH) algorithm has been developed to improve the effectiveness of the traditional VFH path planning algorithm overcoming the side effects of using static parameters. This new algorithm permits the adaptation of planning parameters for the different type of areas in an environment. Genetic Algorithms are used to fit the best VFH parameters to each type of sector and, afterwards, every section in the map is labelled with the sector-type which best represents it. The Player/Stage simulation platform has been chosen for making all sort of tests and to prove the new algorithm's adequateness. Even though there is still much work to be carried out, the developed algorithm showed good navigation properties and turned out to be softer and more effective than the traditional VFH algorithm.

  15. Boosted di-boson from a mixed heavy stop

    SciTech Connect

    Ghosh, Diptimoy

    2013-12-01

    The lighter mass eigenstate ($\\widetilde{t}_1$) of the two top squarks, the scalar superpartners of the top quark, is extremely difficult to discover if it is almost degenerate with the lightest neutralino ($\\widetilde{\\chi}_1^0$), the lightest and stable supersymmetric particle in the R-parity conserving supersymmetry. The current experimental bound on $\\widetilde{t}_1$ mass in this scenario stands only around 200 GeV. For such a light $\\widetilde{t}_1$, the heavier top squark ($\\widetilde{t}_2$) can also be around the TeV scale. Moreover, the high value of the higgs ($h$) mass prefers the left and right handed top squarks to be highly mixed allowing the possibility of a considerable branching ratio for $\\widetilde{t}_2 \\to \\widetilde{t}_1 h$ and $\\widetilde{t}_2 \\to \\widetilde{t}_1 Z$. In this paper, we explore the above possibility together with the pair production of $\\widetilde{t}_2$ $\\widetilde{t}_2^*$ giving rise to the spectacular di-boson + missing transverse energy final state. For an approximately 1 TeV $\\widetilde{t}_2$ and a few hundred GeV $\\widetilde{t}_1$ the final state particles can be moderately boosted which encourages us to propose a novel search strategy employing the jet substructure technique to tag the boosted $h$ and $Z$. The reconstruction of the $h$ and $Z$ momenta also allows us to construct the stransverse mass $M_{T2}$ providing an additional efficient handle to fight the backgrounds. We show that a 4--5$\\sigma$ signal can be observed at the 14 TeV LHC for $\\sim$ 1 TeV $\\widetilde{t}_2$ with 100 fb$^{-1}$ integrated luminosity.

  16. Esophageal Cancer Dose Escalation Using a Simultaneous Integrated Boost Technique

    SciTech Connect

    Welsh, James; Palmer, Matthew B.; Ajani, Jaffer A.; Liao Zhongxing; Swisher, Steven G.; Hofstetter, Wayne L.; Allen, Pamela K.; Settle, Steven H.; Gomez, Daniel; Likhacheva, Anna; Cox, James D.; Komaki, Ritsuko

    2012-01-01

    Purpose: We previously showed that 75% of radiation therapy (RT) failures in patients with unresectable esophageal cancer are in the gross tumor volume (GTV). We performed a planning study to evaluate if a simultaneous integrated boost (SIB) technique could selectively deliver a boost dose of radiation to the GTV in patients with esophageal cancer. Methods and Materials: Treatment plans were generated using four different approaches (two-dimensional conformal radiotherapy [2D-CRT] to 50.4 Gy, 2D-CRT to 64.8 Gy, intensity-modulated RT [IMRT] to 50.4 Gy, and SIB-IMRT to 64.8 Gy) and optimized for 10 patients with distal esophageal cancer. All plans were constructed to deliver the target dose in 28 fractions using heterogeneity corrections. Isodose distributions were evaluated for target coverage and normal tissue exposure. Results: The 50.4 Gy IMRT plan was associated with significant reductions in mean cardiac, pulmonary, and hepatic doses relative to the 50.4 Gy 2D-CRT plan. The 64.8 Gy SIB-IMRT plan produced a 28% increase in GTV dose and comparable normal tissue doses as the 50.4 Gy IMRT plan; compared with the 50.4 Gy 2D-CRT plan, the 64.8 Gy SIB-IMRT produced significant dose reductions to all critical structures (heart, lung, liver, and spinal cord). Conclusions: The use of SIB-IMRT allowed us to selectively increase the dose to the GTV, the area at highest risk of failure, while simultaneously reducing the dose to the normal heart, lung, and liver. Clinical implications warrant systematic evaluation.

  17. Comparison of composite prostate radiotherapy plan doses with dependent and independent boost phases.

    PubMed

    Narayanasamy, Ganesh; Avila, Gabrielle; Mavroidis, Panayiotis; Papanikolaou, Niko; Gutierrez, Alonso; Baacke, Diana; Shi, Zheng; Stathakis, Sotirios

    2016-09-01

    Prostate cases commonly consist of dual phase planning with a primary plan followed by a boost. Traditionally, the boost phase is planned independently from the primary plan with the risk of generating hot or cold spots in the composite plan. Alternatively, boost phase can be planned taking into account the primary dose. The aim of this study was to compare the composite plans from independently and dependently planned boosts using dosimetric and radiobiological metrics. Ten consecutive prostate patients previously treated at our institution were used to conduct this study on the Raystation™ 4.0 treatment planning system. For each patient, two composite plans were developed: a primary plan with an independently planned boost and a primary plan with a dependently planned boost phase. The primary plan was prescribed to 54 Gy in 30 fractions to the primary planning target volume (PTV1) which includes prostate and seminal vesicles, while the boost phases were prescribed to 24 Gy in 12 fractions to the boost planning target volume (PTV2) that targets only the prostate. PTV coverage, max dose, median dose, target conformity, dose homogeneity, dose to OARs, and probabilities of benefit, injury, and complication-free tumor control (P+) were compared. Statistical significance was tested using either a 2-tailed Student's t-test or Wilcoxon signed-rank test. Dosimetrically, the composite plan with dependent boost phase exhibited smaller hotspots, lower maximum dose to the target without any significant change to normal tissue dose. Radiobiologically, for all but one patient, the percent difference in the P+ values between the two methods was not significant. A large percent difference in P+ value could be attributed to an inferior primary plan. The benefits of considering the dose in primary plan while planning the boost is not significant unless a poor primary plan was achieved.

  18. Adaptive sampler

    DOEpatents

    Watson, B.L.; Aeby, I.

    1980-08-26

    An adaptive data compression device for compressing data is described. The device has a frequency content, including a plurality of digital filters for analyzing the content of the data over a plurality of frequency regions, a memory, and a control logic circuit for generating a variable rate memory clock corresponding to the analyzed frequency content of the data in the frequency region and for clocking the data into the memory in response to the variable rate memory clock.

  19. Adaptive sampler

    DOEpatents

    Watson, Bobby L.; Aeby, Ian

    1982-01-01

    An adaptive data compression device for compressing data having variable frequency content, including a plurality of digital filters for analyzing the content of the data over a plurality of frequency regions, a memory, and a control logic circuit for generating a variable rate memory clock corresponding to the analyzed frequency content of the data in the frequency region and for clocking the data into the memory in response to the variable rate memory clock.

  20. Adaptive antennas

    NASA Astrophysics Data System (ADS)

    Barton, P.

    1987-04-01

    The basic principles of adaptive antennas are outlined in terms of the Wiener-Hopf expression for maximizing signal to noise ratio in an arbitrary noise environment; the analogy with generalized matched filter theory provides a useful aid to understanding. For many applications, there is insufficient information to achieve the above solution and thus non-optimum constrained null steering algorithms are also described, together with a summary of methods for preventing wanted signals being nulled by the adaptive system. The three generic approaches to adaptive weight control are discussed; correlation steepest descent, weight perturbation and direct solutions based on sample matrix conversion. The tradeoffs between hardware complexity and performance in terms of null depth and convergence rate are outlined. The sidelobe cancellor technique is described. Performance variation with jammer power and angular distribution is summarized and the key performance limitations identified. The configuration and performance characteristics of both multiple beam and phase scan array antennas are covered, with a brief discussion of performance factors.

  1. Evaluation of stereotactic body radiotherapy (SBRT) boost in the management of endometrial cancer.

    PubMed

    Demiral, S; Beyzadeoglu, M; Uysal, B; Oysul, K; Kahya, Y Elcim; Sager, O; Dincoglan, F; Gamsiz, H; Dirican, B; Surenkok, S

    2013-01-01

    The purpose of this study is to evaluate the use of linear accelerator (LINAC)-based stereotactic body radiotherapy (SBRT) boost with multileaf collimator technique after pelvic radiotherapy (RT) in patients with endometrial cancer. Consecutive patients with endometrial cancer treated using LINAC-based SBRT boost after pelvic RT were enrolled in the study. All patients had undergone surgery including total abdominal hysterectomy and bilateral salpingo-oophorectomy ± pelvic/paraortic lymphadenectomy before RT. Prescribed external pelvic RT dose was 45 Gray (Gy) in 1.8 Gy daily fractions. All patients were treated with SBRT boost after pelvic RT. The prescribed SBRT boost dose to the upper two thirds of the vagina including the vaginal vault was 18 Gy delivered in 3 fractions with 1-week intervals. Gastrointestinal and genitourinary toxicity was assessed using the Common Terminology Criteria for Adverse Events version 3 (CTCAE v3).Between April 2010 and May 2011, 18 patients with stage I-III endometrial cancer were treated with LINAC-based SBRT boost after pelvic RT. At a median follow-up of 24 (8-26) months with magnetic resonance imaging (MRI) and gynecological examination, local control rate of the study group was 100 % with negligible acute and late toxicity.LINAC-based SBRT boost to the vaginal cuff is a feasible gynecological cancer treatment modality with excellent local control and minimal toxicity that may replace traditional brachytherapy boost in the management of endometrial cancer. PMID:23374003

  2. A novel sparse boosting method for crater detection in the high resolution planetary image

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Yang, Gang; Guo, Lei

    2015-09-01

    Impact craters distributed on planetary surface become one of the main barriers during the soft landing of planetary probes. In order to accelerate the crater detection, in this paper, we present a new sparse boosting (SparseBoost) method for automatic detection of sub-kilometer craters. The SparseBoost method integrates an improved sparse kernel density estimator (RSDE-WL1) into the Boost algorithm and the RSDE-WL1 estimator is achieved by introducing weighted l1 penalty term into the reduced set density estimator. An iterative algorithm is proposed to implement the RSDE-WL1. The SparseBoost algorithm has the advantage of fewer selected features and simpler representation of the weak classifiers compared with the Boost algorithm. Our SparseBoost based crater detection method is evaluated on a large and high resolution image of Martian surface. Experimental results demonstrate that the proposed method can achieve less computational complexity in comparison with other crater detection methods in terms of selected features.

  3. Cosmos++: Relativistic Magnetohydrodynamics on Unstructured Grids with Local Adaptive Refinement

    SciTech Connect

    Anninos, P; Fragile, P C; Salmonson, J D

    2005-05-06

    A new code and methodology are introduced for solving the fully general relativistic magnetohydrodynamic (GRMHD) equations using time-explicit, finite-volume discretization. The code has options for solving the GRMHD equations using traditional artificial-viscosity (AV) or non-oscillatory central difference (NOCD) methods, or a new extended AV (eAV) scheme using artificial-viscosity together with a dual energy-flux-conserving formulation. The dual energy approach allows for accurate modeling of highly relativistic flows at boost factors well beyond what has been achieved to date by standard artificial viscosity methods. it provides the benefit of Godunov methods in capturing high Lorentz boosted flows but without complicated Riemann solvers, and the advantages of traditional artificial viscosity methods in their speed and flexibility. Additionally, the GRMHD equations are solved on an unstructured grid that supports local adaptive mesh refinement using a fully threated oct-tree (in three dimensions) network to traverse the grid hierarchy across levels and immediate neighbors. A number of tests are presented to demonstrate robustness of the numerical algorithms and adaptive mesh framework over a wide spectrum of problems, boosts, and astrophysical applications, including relativistic shock tubes, shock collisions, magnetosonic shocks, Alfven wave propagation, blast waves, magnetized Bondi flow, and the magneto-rotational instability in Kerr black hole spacetimes.

  4. Impact of the Radiation Boost on Outcomes After Breast-Conserving Surgery and Radiation

    SciTech Connect

    Murphy, Colin; Anderson, Penny R.; Li Tianyu; Bleicher, Richard J.; Sigurdson, Elin R.; Goldstein, Lori J.; Swaby, Ramona; Denlinger, Crystal; Dushkin, Holly; Nicolaou, Nicos; Freedman, Gary M.

    2011-09-01

    Purpose: We examined the impact of radiation tumor bed boost parameters in early-stage breast cancer on local control and cosmetic outcomes. Methods and Materials: A total of 3,186 women underwent postlumpectomy whole-breast radiation with a tumor bed boost for Tis to T2 breast cancer from 1970 to 2008. Boost parameters analyzed included size, energy, dose, and technique. Endpoints were local control, cosmesis, and fibrosis. The Kaplan-Meier method was used to estimate actuarial incidence, and a Cox proportional hazard model was used to determine independent predictors of outcomes on multivariate analysis (MVA). The median follow-up was 78 months (range, 1-305 months). Results: The crude cosmetic results were excellent in 54%, good in 41%, and fair/poor in 5% of patients. The 10-year estimate of an excellent cosmesis was 66%. On MVA, independent predictors for excellent cosmesis were use of electron boost, lower electron energy, adjuvant systemic therapy, and whole-breast IMRT. Fibrosis was reported in 8.4% of patients. The actuarial incidence of fibrosis was 11% at 5 years and 17% at 10 years. On MVA, independent predictors of fibrosis were larger cup size and higher boost energy. The 10-year actuarial local failure was 6.3%. There was no significant difference in local control by boost method, cut-out size, dose, or energy. Conclusions: Likelihood of excellent cosmesis or fibrosis are associated with boost technique, electron energy, and cup size. However, because of high local control and rare incidence of fair/poor cosmesis with a boost, the anatomy of the patient and tumor cavity should ultimately determine the necessary boost parameters.

  5. Retroperitoneal Sarcoma (RPS) High Risk Gross Tumor Volume Boost (HR GTV Boost) Contour Delineation Agreement Among NRG Sarcoma Radiation and Surgical Oncologists

    PubMed Central

    Baldini, Elizabeth H.; Bosch, Walter; Kane, John M.; Abrams, Ross A.; Salerno, Kilian E.; Deville, Curtiland; Raut, Chandrajit P.; Petersen, Ivy A.; Chen, Yen-Lin; Mullen, John T.; Millikan, Keith W.; Karakousis, Giorgos; Kendrick, Michael L.; DeLaney, Thomas F.; Wang, Dian

    2015-01-01

    Purpose Curative intent management of retroperitoneal sarcoma (RPS) requires gross total resection. Preoperative radiotherapy (RT) often is used as an adjuvant to surgery, but recurrence rates remain high. To enhance RT efficacy with acceptable tolerance, there is interest in delivering “boost doses” of RT to high-risk areas of gross tumor volume (HR GTV) judged to be at risk for positive resection margins. We sought to evaluate variability in HR GTV boost target volume delineation among collaborating sarcoma radiation and surgical oncologist teams. Methods Radiation planning CT scans for three cases of RPS were distributed to seven paired radiation and surgical oncologist teams at six institutions. Teams contoured HR GTV boost volumes for each case. Analysis of contour agreement was performed using the simultaneous truth and performance level estimation (STAPLE) algorithm and kappa statistics. Results HRGTV boost volume contour agreement between the seven teams was “substantial” or “moderate” for all cases. Agreement was best on the torso wall posteriorly (abutting posterior chest abdominal wall) and medially (abutting ipsilateral para-vertebral space and great vessels). Contours varied more significantly abutting visceral organs due to differing surgical opinions regarding planned partial organ resection. Conclusions Agreement of RPS HRGTV boost volumes between sarcoma radiation and surgical oncologist teams was substantial to moderate. Differences were most striking in regions abutting visceral organs, highlighting the importance of collaboration between the radiation and surgical oncologist for “individualized” target delineation on the basis of areas deemed at risk and planned resection. PMID:26018727

  6. RS-34 Phoenix (Peacekeeper Post Boost Propulsion System) Utilization Study

    NASA Technical Reports Server (NTRS)

    Esther, Elizabeth A.; Kos, Larry; Bruno, Cy

    2012-01-01

    The Advanced Concepts Office (ACO) at the NASA Marshall Space Flight Center (MSFC) in conjunction with Pratt & Whitney Rocketdyne conducted a study to evaluate potential in-space applications for the Rocketdyne produced RS-34 propulsion system. The existing RS-34 propulsion system is a remaining asset from the decommissioned United States Air Force Peacekeeper ICBM program; specifically the pressure-fed storable bipropellant Stage IV Post Boost Propulsion System, renamed Phoenix. MSFC gained experience with the RS-34 propulsion system on the successful Ares I-X flight test program flown in October 2009. RS-34 propulsion system components were harvested from stages supplied by the USAF and used on the Ares I-X Roll control system (RoCS). The heritage hardware proved extremely robust and reliable and sparked interest for further utilization on other potential in-space applications. Subsequently, MSFC is working closely with the USAF to obtain all the remaining RS-34 stages for re-use opportunities. Prior to pursuit of securing the hardware, MSFC commissioned the Advanced Concepts Office to understand the capability and potential applications for the RS-34 Phoenix stage as it benefits NASA, DoD, and commercial industry. Originally designed, the RS-34 Phoenix provided in-space six-degrees-of freedom operational maneuvering to deploy multiple payloads at various orbital locations. The RS-34 Phoenix Utilization Study sought to understand how the unique capabilities of the RS-34 Phoenix and its application to six candidate missions: 1) small satellite delivery (SSD), 2) orbital debris removal (ODR), 3) ISS re-supply, 4) SLS kick stage, 5) manned GEO servicing precursor mission, and an Earth-Moon L-2 Waypoint mission. The small satellite delivery and orbital debris removal missions were found to closely mimic the heritage RS-34 mission. It is believed that this technology will enable a small, low-cost multiple satellite delivery to multiple orbital locations with a single

  7. RS-34 Phoenix (Peacekeeper Post Boost Propulsion System) Utilization Study

    NASA Technical Reports Server (NTRS)

    Esther, Elizabeth A.; Kos, Larry; Burnside, Christopher G.; Bruno, Cy

    2013-01-01

    The Advanced Concepts Office (ACO) at the NASA Marshall Space Flight Center (MSFC) in conjunction with Pratt & Whitney Rocketdyne conducted a study to evaluate potential in-space applications for the Rocketdyne produced RS-34 propulsion system. The existing RS-34 propulsion system is a remaining asset from the de-commissioned United States Air Force Peacekeeper ICBM program, specifically the pressure-fed storable bipropellant Stage IV Post Boost Propulsion System, renamed Phoenix. MSFC gained experience with the RS-34 propulsion system on the successful Ares I-X flight test program flown in October 2009. RS-34 propulsion system components were harvested from stages supplied by the USAF and used on the Ares I-X Roll control system (RoCS). The heritage hardware proved extremely robust and reliable and sparked interest for further utilization on other potential in-space applications. MSFC is working closely with the USAF to obtain RS-34 stages for re-use opportunities. Prior to pursuit of securing the hardware, MSFC commissioned the Advanced Concepts Office to understand the capability and potential applications for the RS-34 Phoenix stage as it benefits NASA, DoD, and commercial industry. As originally designed, the RS-34 Phoenix provided in-space six-degrees-of freedom operational maneuvering to deploy multiple payloads at various orbital locations. The RS-34 Phoenix Utilization Study sought to understand how the unique capabilities of the RS-34 Phoenix and its application to six candidate missions: 1) small satellite delivery (SSD), 2) orbital debris removal (ODR), 3) ISS re-supply, 4) SLS kick stage, 5) manned GEO servicing precursor mission, and an Earth-Moon L-2 Waypoint mission. The small satellite delivery and orbital debris removal missions were found to closely mimic the heritage RS-34 mission. It is believed that this technology will enable a small, low-cost multiple satellite delivery to multiple orbital locations with a single boost. For both the small

  8. Robust 3D face recognition by local shape difference boosting.

    PubMed

    Wang, Yueming; Liu, Jianzhuang; Tang, Xiaoou

    2010-10-01

    This paper proposes a new 3D face recognition approach, Collective Shape Difference Classifier (CSDC), to meet practical application requirements, i.e., high recognition performance, high computational efficiency, and easy implementation. We first present a fast posture alignment method which is self-dependent and avoids the registration between an input face against every face in the gallery. Then, a Signed Shape Difference Map (SSDM) is computed between two aligned 3D faces as a mediate representation for the shape comparison. Based on the SSDMs, three kinds of features are used to encode both the local similarity and the change characteristics between facial shapes. The most discriminative local features are selected optimally by boosting and trained as weak classifiers for assembling three collective strong classifiers, namely, CSDCs with respect to the three kinds of features. Different schemes are designed for verification and identification to pursue high performance in both recognition and computation. The experiments, carried out on FRGC v2 with the standard protocol, yield three verification rates all better than 97.9 percent with the FAR of 0.1 percent and rank-1 recognition rates above 98 percent. Each recognition against a gallery with 1,000 faces only takes about 3.6 seconds. These experimental results demonstrate that our algorithm is not only effective but also time efficient. PMID:20724762

  9. Development of cassava periclinal chimera may boost production.

    PubMed

    Bomfim, N; Nassar, N M A

    2014-02-10

    Plant periclinal chimeras are genotypic mosaics arranged concentrically. Trials to produce them to combine different species have been done, but pratical results have not been achieved. We report for the second time the development of a very productive interspecific periclinal chimera in cassava. It has very large edible roots up to 14 kg per plant at one year old compared to 2-3 kg in common varieties. The epidermal tissue formed was from Manihot esculenta cultivar UnB 032, and the subepidermal and internal tissue from the wild species, Manihot fortalezensis. We determined the origin of tissues by meiotic and mitotic chromosome counts, plant anatomy and morphology. Epidermal features displayed useful traits to deduce tissue origin: cell shape and size, trichome density and stomatal length. Chimera roots had a wholly tuberous and edible constitution with smaller starch granule size and similar distribution compared to cassava. Root size enlargement might have been due to an epigenetic effect. These results suggest a new line of improved crop based on the development of interspecific chimeras composed of different combinations of wild and cultivated species. It promises boosting cassava production through exceptional root enlargement.

  10. Electrochemical, H2O2-Boosted Catalytic Oxidation System

    NASA Technical Reports Server (NTRS)

    Akse, James R.; Thompson, John O.; Schussel, Leonard J.

    2004-01-01

    An improved water-sterilizing aqueous-phase catalytic oxidation system (APCOS) is based partly on the electrochemical generation of hydrogen peroxide (H2O2). This H2O2-boosted system offers significant improvements over prior dissolved-oxygen water-sterilizing systems in the way in which it increases oxidation capabilities, supplies H2O2 when needed, reduces the total organic carbon (TOC) content of treated water to a low level, consumes less energy than prior systems do, reduces the risk of contamination, and costs less to operate. This system was developed as a variant of part of an improved waste-management subsystem of the life-support system of a spacecraft. Going beyond its original intended purpose, it offers the advantage of being able to produce H2O2 on demand for surface sterilization and/or decontamination: this is a major advantage inasmuch as the benign byproducts of this H2O2 system, unlike those of systems that utilize other chemical sterilants, place no additional burden of containment control on other spacecraft air- or water-reclamation systems.

  11. Tamoxifen reduces fat mass by boosting reactive oxygen species.

    PubMed

    Liu, L; Zou, P; Zheng, L; Linarelli, L E; Amarell, S; Passaro, A; Liu, D; Cheng, Z

    2015-01-01

    As the pandemic of obesity is growing, a variety of animal models have been generated to study the mechanisms underlying the increased adiposity and development of metabolic disorders. Tamoxifen (Tam) is widely used to activate Cre recombinase that spatiotemporally controls target gene expression and regulates adiposity in laboratory animals. However, a critical question remains as to whether Tam itself affects adiposity and possibly confounds the functional study of target genes in adipose tissue. Here we administered Tam to Cre-absent forkhead box O1 (FoxO1) floxed mice (f-FoxO1) and insulin receptor substrate Irs1/Irs2 double floxed mice (df-Irs) and found that Tam induced approximately 30% reduction (P<0.05) in fat mass with insignificant change in body weight. Mechanistically, Tam promoted reactive oxygen species (ROS) production, apoptosis and autophagy, which was associated with downregulation of adipogenic regulator peroxisome proliferator-activated receptor gamma and dedifferentiation of mature adipocytes. However, normalization of ROS potently suppressed Tam-induced apoptosis, autophagy and adipocyte dedifferentiation, suggesting that ROS may account, at least in part, for the changes. Importantly, Tam-induced ROS production and fat mass reduction lasted for 4-5 weeks in the f-FoxO1 and df-Irs mice. Our data suggest that Tam reduces fat mass via boosting ROS, thus making a recovery period crucial for posttreatment study. PMID:25569103

  12. Fault diagnosis algorithm based on switching function for boost converters

    NASA Astrophysics Data System (ADS)

    Cho, H.-K.; Kwak, S.-S.; Lee, S.-H.

    2015-07-01

    A fault diagnosis algorithm, which is necessary for constructing a reliable power conversion system, should detect fault occurrences as soon as possible to protect the entire system from fatal damages resulting from system malfunction. In this paper, a fault diagnosis algorithm is proposed to detect open- and short-circuit faults that occur in a boost converter switch. The inductor voltage is abnormally kept at a positive DC value during a short-circuit fault in the switch or at a negative DC value during an open-circuit fault condition until the inductor current becomes zero. By employing these abnormal properties during faulty conditions, the inductor voltage is compared with the switching function to detect each fault type by generating fault alarms when a fault occurs. As a result, from the fault alarm, a decision is made in response to the fault occurrence and the fault type in less than two switching time periods using the proposed algorithm constructed in analogue circuits. In addition, the proposed algorithm has good resistivity to discontinuous current-mode operation. As a result, this algorithm features the advantages of low cost and simplicity because of its simple analogue circuit configuration.

  13. Controlled Vocabularies Boost International Participation and Normalization of Searches

    NASA Technical Reports Server (NTRS)

    Olsen, Lola M.

    2006-01-01

    The Global Change Master Directory's (GCMD) science staff set out to document Earth science data and provide a mechanism for it's discovery in fulfillment of a commitment to NASA's Earth Science progam and to the Committee on Earth Observation Satellites' (CEOS) International Directory Network (IDN.) At the time, whether to offer a controlled vocabulary search or a free-text search was resolved with a decision to support both. The feedback from the user community indicated that being asked to independently determine the appropriate 'English" words through a free-text search would be very difficult. The preference was to be 'prompted' for relevant keywords through the use of a hierarchy of well-designed science keywords. The controlled keywords serve to 'normalize' the search through knowledgeable input by metadata providers. Earth science keyword taxonomies were developed, rules for additions, deletions, and modifications were created. Secondary sets of controlled vocabularies for related descriptors such as projects, data centers, instruments, platforms, related data set link types, and locations, along with free-text searches assist users in further refining their search results. Through this robust 'search and refine' capability in the GCMD users are directed to the data and services they seek. The next step in guiding users more directly to the resources they desire is to build a 'reasoning' capability for search through the use of ontologies. Incorporating twelve sets of Earth science keyword taxonomies has boosted the GCMD S ability to help users define and more directly retrieve data of choice.

  14. Memory boosting effect of Citrus limon, Pomegranate and their combinations.

    PubMed

    Riaz, Azra; Khan, Rafeeq Alam; Algahtani, Hussein A

    2014-11-01

    Memory is greatly influenced by factors like food, stress and quality of sleep, hence present study was designed to evaluate the effect of Citrus limon and Pomegranate juices on memory of mice using Harvard Panlab Passive Avoidance response apparatus controlled through LE2708 Programmer. Passive avoidance is fear-motivated tests used to assess short or long-term memory of small animals, which measures latency to enter into the black compartment. Animals at MCLD showed highly significant and significant increase in latency to enter into the black compartment after 3 and 24 hours respectively than control, animals at HCLD showed significant increase in latency only after 3hours. Animals both at low and moderate doses of pomegranate showed significant increase in test latency after 3 hours, while animals at high dose showed highly significant and significant increase in latency after 3 and 24 hours respectively. There was highly significant and significant increase in latency in animals at CPJ-1 combination after 3 and 24 hours respectively; however animals received CPJ-2 combination showed significant increase in latency only after 3 hours as compare to control. These results suggest that Citrus limon and Pomegranate has phytochemicals and essential nutrients which boost memory, particularly short term memory. Hence it may be concluded that flavonoids in these juices may be responsible for memory enhancing effects and a synergistic effect is observed by CPJ-1 and CPJ-2 combinations. PMID:25362607

  15. Clinton budget squeezes EPA, boosts federal R D

    SciTech Connect

    Begley, R.

    1993-04-21

    Although Environmental Protection Agency chief Carol Browner tried to portray the numbers in a positive light, a budget cut is a budget cut and that is what she was handed by her new boss. Despite Clinton Administration rhetoric on the environment, the $6.4-billion EPA budget for fiscal 1994 is down almost 8% for 1993. The superfund program is hit hardest, down 6%, to $1.5 billion. Browner counts funds from the President's 1993 stimulus bill--currently in limbo in Congress--in her 1994 budget to arrive at an increase. She says 1994 will bring greater emphasis to pollution prevention, collaborative programs with industry on toxic releases, and improvement in EPA's science and research activities. EPA's air and pesticides programs will get more money, as well hazardous waste, which EPA says will [open quotes]eliminate unnecessary and burdensome requirements[close quotes] on industry and speed up corrective action. Water quality programs will be cut, as will the toxic substances program, although the Toxic Release Inventory will get a boost.

  16. Negative emotion boosts quality of visual working memory representation.

    PubMed

    Xie, Weizhen; Zhang, Weiwei

    2016-08-01

    Negative emotion impacts a variety of cognitive processes, including working memory (WM). The present study investigated whether negative emotion modulated WM capacity (quantity) or resolution (quality), 2 independent limits on WM storage. In Experiment 1, observers tried to remember several colors over 1-s delay and then recalled the color of a randomly picked memory item by clicking a best-matching color on a continuous color wheel. On each trial, before the visual WM task, 1 of 3 emotion conditions (negative, neutral, or positive) was induced by having observers to rate the valence of an International Affective Picture System image. Visual WM under negative emotion showed enhanced resolution compared with neutral and positive conditions, whereas the number of retained representations was comparable across the 3 emotion conditions. These effects were generalized to closed-contour shapes in Experiment 2. To isolate the locus of these effects, Experiment 3 adopted an iconic memory version of the color recall task by eliminating the 1-s retention interval. No significant change in the quantity or quality of iconic memory was observed, suggesting that the resolution effects in the first 2 experiments were critically dependent on the need to retain memory representations over a short period of time. Taken together, these results suggest that negative emotion selectively boosts visual WM quality, supporting the dissociable nature quantitative and qualitative aspects of visual WM representation. (PsycINFO Database Record PMID:27078744

  17. ArborZ: PHOTOMETRIC REDSHIFTS USING BOOSTED DECISION TREES

    SciTech Connect

    Gerdes, David W.; Sypniewski, Adam J.; McKay, Timothy A.; Hao, Jiangang; Weis, Matthew R.; Wechsler, Risa H.; Busha, Michael T.

    2010-06-01

    Precision photometric redshifts will be essential for extracting cosmological parameters from the next generation of wide-area imaging surveys. In this paper, we introduce a photometric redshift algorithm, ArborZ, based on the machine-learning technique of boosted decision trees. We study the algorithm using galaxies from the Sloan Digital Sky Survey (SDSS) and from mock catalogs intended to simulate both the SDSS and the upcoming Dark Energy Survey. We show that it improves upon the performance of existing algorithms. Moreover, the method naturally leads to the reconstruction of a full probability density function (PDF) for the photometric redshift of each galaxy, not merely a single 'best estimate' and error, and also provides a photo-z quality figure of merit for each galaxy that can be used to reject outliers. We show that the stacked PDFs yield a more accurate reconstruction of the redshift distribution N(z). We discuss limitations of the current algorithm and ideas for future work.

  18. Predictors of virologic response to ritonavir-boosted protease inhibitors.

    PubMed

    Marcelin, Anne-Genevieve; Flandre, Philippe; Peytavin, Gilles; Calvez, Vincent

    2005-01-01

    The primary mechanism of resistance to protease inhibitors involves the stepwise accumulation of mutations that alter and block the substrate binding site of HIV protease. The large degree of cross-resistance among the different protease inhibitors is a source of considerable concern for the management of patients after treatment failure. Although the output of HIV-resistance tests has been based on therapeutically arbitrary criteria, there is now an ongoing move towards correlating test interpretation with virologic outcomes on treatment. This approach is undeniably superior, in principle, for tests intended to guide drug choices. However, the predictive accuracy of a given stratagem that links genotype or phenotype to drug response is strongly influenced by the study design, data capture and the analytical methodology used to derive it. There is no definitively superior methodology for generating a genotype-response association for use in interpreting a resistance test, and the various approaches used to date all have their strengths and weaknesses. Combining the information of therapeutic drug monitoring and resistance tests is likely to be of greatest clinical utility in antiretroviral-experienced patients harboring HIV strains with reduced susceptibility. The combination of pharmacologic and virologic parameters as a predictor of the virologic response has been merged into the parameter known as "inhibitory quotient". This article discusses the potential interest of the use of inhibitory quotients as an approach for enhancing the potency and durability of boosted protease inhibitors against protease inhibitor-resistant viruses. PMID:16425962

  19. Boosting training for myoelectric pattern recognition using Mixed-LDA.

    PubMed

    Liu, Jianwei; Sheng, Xinjun; Zhang, Dingguo; Zhu, Xiangyang

    2014-01-01

    Pattern recognition based myoelectric prostheses (MP) need a training procedure for calibrating the classifier. Due to the non-stationarity inhered in surface electromyography (sEMG) signals, the system should be retrained day by day in long-term use of MP. To boost the training procedure in later periods, we propose a method, namely Mixed-LDA, which computes the parameters of LDA through combining the model estimated on the incoming training samples of the current day with the prior models available from earlier days. An experiment ranged for 10 days on 5 subjects was carried out to simulate the long-term use of MP. Results show that the Mixed-LDA is significantly better than the baseline method (LDA) when few samples are used as training set in the new (current) day. For instance, in the task including 13 hand and wrist motions, the average classification rate of the Mixed-LDA is 88.74% when the number of training samples is 104 (LDA: 79.32%). This implies that the approach has the potential to improve the usability of MP based on pattern recognition by reducing the training time.

  20. Memory boosting effect of Citrus limon, Pomegranate and their combinations.

    PubMed

    Riaz, Azra; Khan, Rafeeq Alam; Algahtani, Hussein A

    2014-11-01

    Memory is greatly influenced by factors like food, stress and quality of sleep, hence present study was designed to evaluate the effect of Citrus limon and Pomegranate juices on memory of mice using Harvard Panlab Passive Avoidance response apparatus controlled through LE2708 Programmer. Passive avoidance is fear-motivated tests used to assess short or long-term memory of small animals, which measures latency to enter into the black compartment. Animals at MCLD showed highly significant and significant increase in latency to enter into the black compartment after 3 and 24 hours respectively than control, animals at HCLD showed significant increase in latency only after 3hours. Animals both at low and moderate doses of pomegranate showed significant increase in test latency after 3 hours, while animals at high dose showed highly significant and significant increase in latency after 3 and 24 hours respectively. There was highly significant and significant increase in latency in animals at CPJ-1 combination after 3 and 24 hours respectively; however animals received CPJ-2 combination showed significant increase in latency only after 3 hours as compare to control. These results suggest that Citrus limon and Pomegranate has phytochemicals and essential nutrients which boost memory, particularly short term memory. Hence it may be concluded that flavonoids in these juices may be responsible for memory enhancing effects and a synergistic effect is observed by CPJ-1 and CPJ-2 combinations.

  1. OBSERVATIONS OF DOPPLER BOOSTING IN KEPLER LIGHT CURVES

    SciTech Connect

    Van Kerkwijk, Marten H.; Breton, Rene P.; Justham, Stephen; Rappaport, Saul A.; Podsiadlowski, Philipp; Han, Zhanwen

    2010-05-20

    Among the initial results from Kepler were two striking light curves, for KOI 74 and KOI 81, in which the relative depths of the primary and secondary eclipses showed that the more compact, less luminous object was hotter than its stellar host. That result became particularly intriguing because a substellar mass had been derived for the secondary in KOI 74, which would make the high temperature challenging to explain; in KOI 81, the mass range for the companion was also reported to be consistent with a substellar object. We re-analyze the Kepler data and demonstrate that both companions are likely to be white dwarfs. We also find that the photometric data for KOI 74 show a modulation in brightness as the more luminous star orbits, due to Doppler boosting. The magnitude of the effect is sufficiently large that we can use it to infer a radial velocity amplitude accurate to 1 km s{sup -1}. As far as we are aware, this is the first time a radial-velocity curve has been measured photometrically. Combining our velocity amplitude with the inclination and primary mass derived from the eclipses and primary spectral type, we infer a secondary mass of 0.22 {+-} 0.03 M{sub sun}. We use our estimates to consider the likely evolutionary paths and mass-transfer episodes of these binary systems.

  2. Heterodyning Time Resolution Boosting for Velocimetry and Reflectivity Measurements

    SciTech Connect

    Erskine, D J

    2004-08-02

    A theoretical technique is described for boosting the temporal resolving power by several times, of detectors such as streak cameras in experiments that measure light reflected from or transmitted through a target, including velocity interferometer (VISAR) measurements. This is a means of effectively increasing the number of resolvable time bins in a streak camera record past the limit imposed by input slit width and blur on the output phosphor screen. The illumination intensity is modulated sinusoidally at a frequency similar to the limiting time response of the detector. A heterodyning effect beats the high frequency science signal down a lower frequency beat signal, which is recorded together with the conventional science signal. Using 3 separate illuminating channels having different phases, the beat term is separated algebraically from the conventional signal. By numerically reversing the heterodyning, and combining with the ordinary signal, the science signal can be reconstructed to better effective time resolution than the detector used alone. The effective time resolution can be approximately halved for a single modulation frequency, and further decreased inversely proportional to the number of independent modulation frequencies employed.

  3. Hard matching for boosted tops at two loops

    NASA Astrophysics Data System (ADS)

    Hoang, André H.; Pathak, Aditya; Pietrulewicz, Piotr; Stewart, Iain W.

    2015-12-01

    Cross sections for top quarks provide very interesting physics opportunities, being both sensitive to new physics and also perturbatively tractable due to the large top quark mass. Rigorous factorization theorems for top cross sections can be derived in several kinematic scenarios, including the boosted regime in the peak region that we consider here. In the context of the corresponding factorization theorem for e + e - collisions we extract the last missing ingredient that is needed to evaluate the cross section differential in the jet-mass at two-loop order, namely the matching coefficient at the scale μ≃ m t . Our extraction also yields the final ingredients needed to carry out logarithmic re-summation at next-to-next-to-leading logarithmic order (or N3LL if we ignore the missing 4-loop cusp anomalous dimension). This coefficient exhibits an amplitude level rapidity logarithm starting at O({α}_s^2) due to virtual top quark loops, which we treat using rapidity renormalization group (RG) evolution. Interestingly, this rapidity RG evolution appears in the matching coefficient between two effective theories around the heavy quark mass scale μ ≃ m t .

  4. Predicting Fusarium head blight epidemics with boosted regression trees.

    PubMed

    Shah, D A; De Wolf, E D; Paul, P A; Madden, L V

    2014-07-01

    Predicting major Fusarium head blight (FHB) epidemics allows for the judicious use of fungicides in suppressing disease development. Our objectives were to investigate the utility of boosted regression trees (BRTs) for predictive modeling of FHB epidemics in the United States, and to compare the predictive performances of the BRT models with those of logistic regression models we had developed previously. The data included 527 FHB observations from 15 states over 26 years. BRTs were fit to a training data set of 369 FHB observations, in which FHB epidemics were classified as either major (severity ≥ 10%) or non-major (severity < 10%), linked to a predictor matrix consisting of 350 weather-based variables and categorical variables for wheat type (spring or winter), presence or absence of corn residue, and cultivar resistance. Predictive performance was estimated on a test (holdout) data set consisting of the remaining 158 observations. BRTs had a misclassification rate of 0.23 on the test data, which was 31% lower than the average misclassification rate over 15 logistic regression models we had presented earlier. The strongest predictors were generally one of mean daily relative humidity, mean daily temperature, and the number of hours in which the temperature was between 9 and 30°C and relative humidity ≥ 90% simultaneously. Moreover, the predicted risk of major epidemics increased substantially when mean daily relative humidity rose above 70%, which is a lower threshold than previously modeled for most plant pathosystems. BRTs led to novel insights into the weather-epidemic relationship.

  5. The dark matter annihilation boost from low-temperature reheating

    NASA Astrophysics Data System (ADS)

    Erickcek, Adrienne L.

    2015-11-01

    The evolution of the Universe between inflation and the onset of big bang nucleosynthesis is difficult to probe and largely unconstrained. This ignorance profoundly limits our understanding of dark matter: we cannot calculate its thermal relic abundance without knowing when the Universe became radiation dominated. Fortunately, small-scale density perturbations provide a probe of the early Universe that could break this degeneracy. If dark matter is a thermal relic, density perturbations that enter the horizon during an early matter-dominated era grow linearly with the scale factor prior to reheating. The resulting abundance of substructure boosts the annihilation rate by several orders of magnitude, which can compensate for the smaller annihilation cross sections that are required to generate the observed dark matter density in these scenarios. In particular, thermal relics with masses less than a TeV that thermally and kinetically decouple prior to reheating may already be ruled out by Fermi-LAT observations of dwarf spheroidal galaxies. Although these constraints are subject to uncertainties regarding the internal structure of the microhalos that form from the enhanced perturbations, they open up the possibility of using gamma-ray observations to learn about the reheating of the Universe.

  6. How One Clinic Got a Big Boost in HPV Vaccination Rates

    MedlinePlus

    ... One Clinic Got a Big Boost in HPV Vaccination Rates The cervical cancer vaccine was treated as ... the United States, lagging far behind other recommended vaccinations in this age group. But, by lumping HPV ...

  7. Experimental Treatment for Duchenne Muscular Dystrophy Gets Boost from Existing Medication

    MedlinePlus

    ... 2013 March 2013 (historical) Experimental Treatment for Duchenne Muscular Dystrophy Gets Boost from Existing Medication A readily available ... effects of a promising experimental treatment for Duchenne muscular dystrophy (DMD), according to research partially funded by the ...

  8. The Effect of Element Formulation on the Prediction of Boost Effects in Numerical Tube Bending

    SciTech Connect

    Bardelcik, A.; Worswick, M.J.

    2005-08-05

    This paper presents advanced FE models of the pre-bending process to investigate the effect of element formulation on the prediction of boost effects in tube bending. Tube bending experiments are conducted with 3'' (OD) IF (Interstitial-Free) steel tube on a fully instrumented Eagle EPT-75 servo-hydraulic mandrel-rotary draw tube bender. Experiments were performed in which the bending boost was varied at three levels and resulted in consistent trends in the strain and thickness distribution within the pre-bent tubes. A numerical model of the rotary draw tube bender was used to simulate pre-bending of the IF tube with the three levels of boost from the experiments. To examine the effect of element formulation on the prediction of boost, the tube was modeled with shell and solid elements. Both models predicted the overall strain and thickness results well, but showed different trends in each of the models.

  9. Boosted objects and jet substructure at the LHC: Report of BOOST2012, held at IFIC Valencia, 23rd-27th of July 2012

    SciTech Connect

    Altheimer, A.

    2014-03-21

    This report of the BOOST2012 workshop presents the results of four working groups that studied key aspects of jet substructure. We discuss the potential of first-principle QCD calculations to yield a precise description of the substructure of jets and study the accuracy of state-of-the-art Monte Carlo tools. Limitations of the experiments’ ability to resolve substructure are evaluated, with a focus on the impact of additional (pile-up) proton proton collisions on jet substructure performance in future LHC operating scenarios. The final section summarizes the lessons learnt from jet substructure analyses in searches for new physics in the production of boosted top quarks.

  10. Boosted objects and jet substructure at the LHC. Report of BOOST2012, held at IFIC Valencia, 23rd-27th of July 2012

    NASA Astrophysics Data System (ADS)

    Altheimer, A.; Arce, A.; Asquith, L.; Backus Mayes, J.; Kuutmann, E. Bergeaas; Berger, J.; Bjergaard, D.; Bryngemark, L.; Buckley, A.; Butterworth, J.; Cacciari, M.; Campanelli, M.; Carli, T.; Chala, M.; Chapleau, B.; Chen, C.; Chou, J. P.; Cornelissen, Th.; Curtin, D.; Dasgupta, M.; Davison, A.; de Almeida Dias, F.; de Cosa, A.; de Roeck, A.; Debenedetti, C.; Doglioni, C.; Ellis, S. D.; Fassi, F.; Ferrando, J.; Fleischmann, S.; Freytsis, M.; Gonzalez Silva, M. L.; de la Hoz, S. Gonzalez; Guescini, F.; Han, Z.; Hook, A.; Hornig, A.; Izaguirre, E.; Jankowiak, M.; Juknevich, J.; Kaci, M.; Kar, D.; Kasieczka, G.; Kogler, R.; Larkoski, A.; Loch, P.; Lopez Mateos, D.; Marzani, S.; Masetti, L.; Mateu, V.; Miller, D. W.; Mishra, K.; Nef, P.; Nordstrom, K.; Oliver Garcia, E.; Penwell, J.; Pilot, J.; Plehn, T.; Rappoccio, S.; Rizzi, A.; Rodrigo, G.; Safonov, A.; Salam, G. P.; Salt, J.; Schaetzel, S.; Schioppa, M.; Schmidt, A.; Scholtz, J.; Schwartzman, A.; Schwartz, M. D.; Segala, M.; Son, M.; Soyez, G.; Spannowsky, M.; Stewart, I.; Strom, D.; Swiatlowski, M.; Sanchez Martinez, V.; Takeuchi, M.; Thaler, J.; Thompson, E. N.; Tran, N. V.; Vermilion, C.; Villaplana, M.; Vos, M.; Wacker, J.; Walsh, J.

    2014-03-01

    This report of the BOOST2012 workshop presents the results of four working groups that studied key aspects of jet substructure. We discuss the potential of first-principle QCD calculations to yield a precise description of the substructure of jets and study the accuracy of state-of-the-art Monte Carlo tools. Limitations of the experiments' ability to resolve substructure are evaluated, with a focus on the impact of additional (pile-up) proton proton collisions on jet substructure performance in future LHC operating scenarios. A final section summarizes the lessons learnt from jet substructure analyses in searches for new physics in the production of boosted top quarks.

  11. Expression of DAI by an oncolytic vaccinia virus boosts the immunogenicity of the virus and enhances antitumor immunity

    PubMed Central

    Hirvinen, Mari; Capasso, Cristian; Guse, Kilian; Garofalo, Mariangela; Vitale, Andrea; Ahonen, Marko; Kuryk, Lukasz; Vähä-Koskela, Markus; Hemminki, Akseli; Fortino, Vittorio; Greco, Dario; Cerullo, Vincenzo

    2016-01-01

    In oncolytic virotherapy, the ability of the virus to activate the immune system is a key attribute with regard to long-term antitumor effects. Vaccinia viruses bear one of the strongest oncolytic activities among all oncolytic viruses. However, its capacity for stimulation of antitumor immunity is not optimal, mainly due to its immunosuppressive nature. To overcome this problem, we developed an oncolytic VV that expresses intracellular pattern recognition receptor DNA-dependent activator of IFN-regulatory factors (DAI) to boost the innate immune system and to activate adaptive immune cells in the tumor. We showed that infection with DAI-expressing VV increases expression of several genes related to important immunological pathways. Treatment with DAI-armed VV resulted in significant reduction in the size of syngeneic melanoma tumors in mice. When the mice were rechallenged with the same tumor, DAI-VV-treated mice completely rejected growth of the new tumor, which indicates immunity established against the tumor. We also showed enhanced control of growth of human melanoma tumors and elevated levels of human T-cells in DAI-VV-treated mice humanized with human peripheral blood mononuclear cells. We conclude that expression of DAI by an oncolytic VV is a promising way to amplify the vaccine potency of an oncolytic vaccinia virus to trigger the innate—and eventually the long-lasting adaptive immunity against cancer. PMID:27626058

  12. Expression of DAI by an oncolytic vaccinia virus boosts the immunogenicity of the virus and enhances antitumor immunity.

    PubMed

    Hirvinen, Mari; Capasso, Cristian; Guse, Kilian; Garofalo, Mariangela; Vitale, Andrea; Ahonen, Marko; Kuryk, Lukasz; Vähä-Koskela, Markus; Hemminki, Akseli; Fortino, Vittorio; Greco, Dario; Cerullo, Vincenzo

    2016-01-01

    In oncolytic virotherapy, the ability of the virus to activate the immune system is a key attribute with regard to long-term antitumor effects. Vaccinia viruses bear one of the strongest oncolytic activities among all oncolytic viruses. However, its capacity for stimulation of antitumor immunity is not optimal, mainly due to its immunosuppressive nature. To overcome this problem, we developed an oncolytic VV that expresses intracellular pattern recognition receptor DNA-dependent activator of IFN-regulatory factors (DAI) to boost the innate immune system and to activate adaptive immune cells in the tumor. We showed that infection with DAI-expressing VV increases expression of several genes related to important immunological pathways. Treatment with DAI-armed VV resulted in significant reduction in the size of syngeneic melanoma tumors in mice. When the mice were rechallenged with the same tumor, DAI-VV-treated mice completely rejected growth of the new tumor, which indicates immunity established against the tumor. We also showed enhanced control of growth of human melanoma tumors and elevated levels of human T-cells in DAI-VV-treated mice humanized with human peripheral blood mononuclear cells. We conclude that expression of DAI by an oncolytic VV is a promising way to amplify the vaccine potency of an oncolytic vaccinia virus to trigger the innate-and eventually the long-lasting adaptive immunity against cancer. PMID:27626058

  13. CRT combined with a sequential VMAT boost in the treatment of upper thoracic esophageal cancer.

    PubMed

    Jin, Xiance; Yi, Jinling; Zhou, Yongqiang; Yan, Huawei; Han, Ce; Xie, Congying

    2013-09-06

    The purpose of this study is to investigate the potential benefits of conformal radiotherapy (CRT) combined with a sequential volumetric-modulated arc therapy (VMAT) boost in the treatment of upper thoracic esophageal cancer. Ten patients with upper thoracic esophageal cancer previously treated with CRT plus a sequential VMAT boost plan were replanned with CRT plus an off-cord CRT boost plan and a full course of VMAT plan. Dosimetric parameters were compared. Results indicated that CRT plus off-cord CRT boost was inferior in planning target volume (PTV) coverage, as indicated by the volume covered by 93% (p = 0.05) and 95% (p = 0.02) of the prescription dose. The full course VMAT plan was superior in conformal index (CI) and conformation number (CN), and produced the highest protection for the spinal cord. CRT plus a VMAT boost demonstrated significant advantages in decreasing the volume of the lung irradiated by a dose of 10 Gy (V10, p = 0.007), 13 Gy (V13, p = 0.003), and 20 Gy (V20, p = 0.001). The full course VMAT plan demonstrated the lowest volume of lung receiving a dose of 30 Gy. CRT plus a VMAT boost for upper thoracic esophageal cancer can improve the target coverage and reduce the volume of lung irradiated by an intermediate dose. This combination may be a promising treatment technique for patients with upper thoracic esophageal cancer.

  14. Postmastectomy radiotherapy with integrated scar boost using helical tomotherapy

    SciTech Connect

    Rong Yi; Yadav, Poonam; Welsh, James S.; Fahner, Tasha; Paliwal, Bhudatt

    2012-10-01

    The purpose of this study was to evaluate helical tomotherapy dosimetry in postmastectomy patients undergoing treatment for chest wall and positive nodal regions with simultaneous integrated boost (SIB) in the scar region using strip bolus. Six postmastectomy patients were scanned with a 5-mm-thick strip bolus covering the scar planning target volume (PTV) plus 2-cm margin. For all 6 cases, the chest wall received a total cumulative dose of 49.3-50.4 Gy with daily fraction size of 1.7-2.0 Gy. Total dose to the scar PTV was prescribed to 58.0-60.2 Gy at 2.0-2.5 Gy per fraction. The supraclavicular PTV and mammary nodal PTV received 1.7-1.9 dose per fraction. Two plans (with and without bolus) were generated for all 6 cases. To generate no-bolus plans, strip bolus was contoured and overrode to air density before planning. The setup reproducibility and delivered dose accuracy were evaluated for all 6 cases. Dose-volume histograms were used to evaluate dose-volume coverage of targets and critical structures. We observed reduced air cavities with the strip bolus setup compared with what we normally see with the full bolus. The thermoluminescence dosimeters (TLD) in vivo dosimetry confirmed accurate dose delivery beneath the bolus. The verification plans performed on the first day megavoltage computed tomography (MVCT) image verified that the daily setup and overall dose delivery was within 2% accuracy compared with the planned dose. The hotspot of the scar PTV in no-bolus plans was 111.4% of the prescribed dose averaged over 6 cases compared with 106.6% with strip bolus. With a strip bolus only covering the postmastectomy scar region, we observed increased dose uniformity to the scar PTV, higher setup reproducibility, and accurate dose delivered beneath the bolus. This study demonstrates the feasibility of using a strip bolus over the scar using tomotherapy for SIB dosimetry in postmastectomy treatments.

  15. Supervised hashing using graph cuts and boosted decision trees.

    PubMed

    Lin, Guosheng; Shen, Chunhua; Hengel, Anton van den

    2015-11-01

    To build large-scale query-by-example image retrieval systems, embedding image features into a binary Hamming space provides great benefits. Supervised hashing aims to map the original features to compact binary codes that are able to preserve label based similarity in the binary Hamming space. Most existing approaches apply a single form of hash function, and an optimization process which is typically deeply coupled to this specific form. This tight coupling restricts the flexibility of those methods, and can result in complex optimization problems that are difficult to solve. In this work we proffer a flexible yet simple framework that is able to accommodate different types of loss functions and hash functions. The proposed framework allows a number of existing approaches to hashing to be placed in context, and simplifies the development of new problem-specific hashing methods. Our framework decomposes the hashing learning problem into two steps: binary code (hash bit) learning and hash function learning. The first step can typically be formulated as binary quadratic problems, and the second step can be accomplished by training a standard binary classifier. For solving large-scale binary code inference, we show how it is possible to ensure that the binary quadratic problems are submodular such that efficient graph cut methods may be used. To achieve efficiency as well as efficacy on large-scale high-dimensional data, we propose to use boosted decision trees as the hash functions, which are nonlinear, highly descriptive, and are very fast to train and evaluate. Experiments demonstrate that the proposed method significantly outperforms most state-of-the-art methods, especially on high-dimensional data. PMID:26440270

  16. Pharmacokinetics and pharmacodynamics of boosted once-daily darunavir.

    PubMed

    Kakuda, Thomas N; Brochot, Anne; Tomaka, Frank L; Vangeneugden, Tony; Van De Casteele, Tom; Hoetelmans, Richard M W

    2014-10-01

    The ability to dose antiretroviral agents once daily simplifies the often complex therapeutic regimens required for the successful treatment of HIV infection. Thus, once-daily dosing can lead to improved patient adherence to medication and, consequently, sustained virological suppression and reduction in the risk of emergence of drug resistance. Several trials have evaluated once-daily darunavir/ritonavir in combination with other antiretrovirals (ARTEMIS and ODIN trials) or as monotherapy (MONET, MONOI and PROTEA trials) in HIV-1-infected adults. Data from ARTEMIS and ODIN demonstrate non-inferiority of once-daily darunavir/ritonavir against a comparator and, together with pharmacokinetic data, have established the suitability of once-daily darunavir/ritonavir for treatment-naive and treatment-experienced patients with no darunavir resistance-associated mutations. The findings of ARTEMIS and ODIN have led to recent updates to treatment guidelines, whereby once-daily darunavir/ritonavir, given with other antiretrovirals, is now a preferred treatment option for antiretroviral-naive adult patients and a simplified treatment option for antiretroviral-experienced adults who have no darunavir resistance-associated mutations. Once-daily dosing with darunavir/ritonavir is an option for treatment-naive and for treatment-experienced paediatric patients with no darunavir resistance-associated mutations based on the findings of the DIONE trial and ARIEL substudy. This article reviews the pharmacokinetics, efficacy, safety and tolerability of once-daily boosted darunavir. The feasibility of darunavir/ritonavir monotherapy as a treatment approach for some patients is also discussed. Finally, data on a fixed-dose combination of 800/150 mg of darunavir/cobicistat once daily are presented, showing comparable darunavir bioavailability to that obtained with 800/100 mg of darunavir/ritonavir once daily. PMID:24951533

  17. Modeling laser wakefield accelerators in a Lorentz boosted frame

    SciTech Connect

    Vay, J.-L.; Geddes, C.G.R.; Cormier-Michel, E.; Grotec, D. P.

    2010-06-15

    Modeling of laser-plasma wakefield accelerators in an optimal frame of reference is shown to produce orders of magnitude speed-up of calculations from first principles. Obtaining these speedups requires mitigation of a high-frequency instability that otherwise limits effectiveness in addition to solutions for handling data input and output in a relativistically boosted frame of reference. The observed high-frequency instability is mitigated using methods including an electromagnetic solver with tunable coefficients, its extension to accomodate Perfectly Matched Layers and Friedman's damping algorithms, as well as an efficient large bandwidth digital filter. It is shown that choosing the frame of the wake as the frame of reference allows for higher levels of filtering and damping than is possible in other frames for the same accuracy. Detailed testing also revealed serendipitously the existence of a singular time step at which the instability level is minimized, independently of numerical dispersion, thus indicating that the observed instability may not be due primarily to Numerical Cerenkov as has been conjectured. The techniques developed for Cerenkov mitigation prove nonetheless to be very efficient at controlling the instability. Using these techniques, agreement at the percentage level is demonstrated between simulations using different frames of reference, with speedups reaching two orders of magnitude for a 0.1 GeV class stages. The method then allows direct and efficient full-scale modeling of deeply depleted laser-plasma stages of 10 GeV-1 TeV for the first time, verifying the scaling of plasma accelerators to very high energies. Over 4, 5 and 6 orders of magnitude speedup is achieved for the modeling of 10 GeV, 100 GeV and 1 TeV class stages, respectively.

  18. Modeling laser wakefield accelerators in a Lorentz boosted frame

    SciTech Connect

    Vay, J.-L.; Geddes, C.G.R.; Cormier-Michel, E.; Grote, D.P.

    2010-09-15

    Modeling of laser-plasma wakefield accelerators in an optimal frame of reference [1] is shown to produce orders of magnitude speed-up of calculations from first principles. Obtaining these speedups requires mitigation of a high frequency instability that otherwise limits effectiveness in addition to solutions for handling data input and output in a relativistically boosted frame of reference. The observed high-frequency instability is mitigated using methods including an electromagnetic solver with tunable coefficients, its extension to accomodate Perfectly Matched Layers and Friedman's damping algorithms, as well as an efficient large bandwidth digital filter. It is shown that choosing theframe of the wake as the frame of reference allows for higher levels of filtering and damping than is possible in other frames for the same accuracy. Detailed testing also revealed serendipitously the existence of a singular time step at which the instability level is minimized, independently of numerical dispersion, thus indicating that the observed instability may not be due primarily to Numerical Cerenkov as has been conjectured. The techniques developed for Cerenkov mitigation prove nonetheless to be very efficient at controlling the instability. Using these techniques, agreement at the percentage level is demonstrated between simulations using different frames of reference, with speedups reaching two orders of magnitude for a 0.1 GeV class stages. The method then allows direct and efficient full-scale modeling of deeply depleted laser-plasma stages of 10 GeV-1 TeV for the first time, verifying the scaling of plasma accelerators to very high energies. Over 4, 5 and 6 orders of magnitude speedup is achieved for the modeling of 10 GeV, 100 GeV and 1 TeV class stages, respectively.

  19. Supervised hashing using graph cuts and boosted decision trees.

    PubMed

    Lin, Guosheng; Shen, Chunhua; Hengel, Anton van den

    2015-11-01

    To build large-scale query-by-example image retrieval systems, embedding image features into a binary Hamming space provides great benefits. Supervised hashing aims to map the original features to compact binary codes that are able to preserve label based similarity in the binary Hamming space. Most existing approaches apply a single form of hash function, and an optimization process which is typically deeply coupled to this specific form. This tight coupling restricts the flexibility of those methods, and can result in complex optimization problems that are difficult to solve. In this work we proffer a flexible yet simple framework that is able to accommodate different types of loss functions and hash functions. The proposed framework allows a number of existing approaches to hashing to be placed in context, and simplifies the development of new problem-specific hashing methods. Our framework decomposes the hashing learning problem into two steps: binary code (hash bit) learning and hash function learning. The first step can typically be formulated as binary quadratic problems, and the second step can be accomplished by training a standard binary classifier. For solving large-scale binary code inference, we show how it is possible to ensure that the binary quadratic problems are submodular such that efficient graph cut methods may be used. To achieve efficiency as well as efficacy on large-scale high-dimensional data, we propose to use boosted decision trees as the hash functions, which are nonlinear, highly descriptive, and are very fast to train and evaluate. Experiments demonstrate that the proposed method significantly outperforms most state-of-the-art methods, especially on high-dimensional data.

  20. Hyperfractionated Concomitant Boost Proton Beam Therapy for Esophageal Carcinoma

    SciTech Connect

    Mizumoto, Masashi; Sugahara, Shinji; Okumura, Toshiyuki; Hashimoto, Takayuki; Oshiro, Yoshiko; Fukumitsu, Nobuyoshi; Nakahara, Akira; Terashima, Hideo; Tsuboi, Koji; Sakurai, Hideyuki

    2011-11-15

    Purpose: To evaluate the efficacy and safety of hyperfractionated concomitant boost proton beam therapy (PBT) for patients with esophageal cancer. Methods and Materials: The study participants were 19 patients with esophageal cancer who were treated with hyperfractionated photon therapy and PBT between 1990 and 2007. The median total dose was 78 GyE (range, 70-83 GyE) over a median treatment period of 48 days (range, 38-53 days). Ten of the 19 patients were at clinical T Stage 3 or 4. Results: There were no cases in which treatment interruption was required because of radiation-induced esophagitis or hematologic toxicity. The overall 1- and 5-year actuarial survival rates for all 19 patients were 79.0% and 42.8%, respectively, and the median survival time was 31.5 months (95% limits: 16.7- 46.3 months). Of the 19 patients, 17 (89%) showed a complete response within 4 months after completing treatment and 2 (11%) showed a partial response, giving a response rate of 100% (19/19). The 1- and 5-year local control rates for all 19 patients were 93.8% and 84.4 %, respectively. Only 1 patient had late esophageal toxicity of Grade 3 at 6 months after hyperfractionated PBT. There were no other nonhematologic toxicities, including no cases of radiation pneumonia or cardiac failure of Grade 3 or higher. Conclusions: The results suggest that hyperfractionated PBT is safe and effective for patients with esophageal cancer. Further studies are needed to establish the appropriate role and treatment schedule for use of PBT for esophageal cancer.

  1. Intelligent sensing sensory quality of Chinese rice wine using near infrared spectroscopy and nonlinear tools.

    PubMed

    Ouyang, Qin; Chen, Quansheng; Zhao, Jiewen

    2016-02-01

    The approach presented herein reports the application of near infrared (NIR) spectroscopy, in contrast with human sensory panel, as a tool for estimating Chinese rice wine quality; concretely, to achieve the prediction of the overall sensory scores assigned by the trained sensory panel. Back propagation artificial neural network (BPANN) combined with adaptive boosting (AdaBoost) algorithm, namely BP-AdaBoost, as a novel nonlinear algorithm, was proposed in modeling. First, the optimal spectra intervals were selected by synergy interval partial least square (Si-PLS). Then, BP-AdaBoost model based on the optimal spectra intervals was established, called Si-BP-AdaBoost model. These models were optimized by cross validation, and the performance of each final model was evaluated according to correlation coefficient (Rp) and root mean square error of prediction (RMSEP) in prediction set. Si-BP-AdaBoost showed excellent performance in comparison with other models. The best Si-BP-AdaBoost model was achieved with Rp=0.9180 and RMSEP=2.23 in the prediction set. It was concluded that NIR spectroscopy combined with Si-BP-AdaBoost was an appropriate method for the prediction of the sensory quality in Chinese rice wine.

  2. Intelligent sensing sensory quality of Chinese rice wine using near infrared spectroscopy and nonlinear tools

    NASA Astrophysics Data System (ADS)

    Ouyang, Qin; Chen, Quansheng; Zhao, Jiewen

    2016-02-01

    The approach presented herein reports the application of near infrared (NIR) spectroscopy, in contrast with human sensory panel, as a tool for estimating Chinese rice wine quality; concretely, to achieve the prediction of the overall sensory scores assigned by the trained sensory panel. Back propagation artificial neural network (BPANN) combined with adaptive boosting (AdaBoost) algorithm, namely BP-AdaBoost, as a novel nonlinear algorithm, was proposed in modeling. First, the optimal spectra intervals were selected by synergy interval partial least square (Si-PLS). Then, BP-AdaBoost model based on the optimal spectra intervals was established, called Si-BP-AdaBoost model. These models were optimized by cross validation, and the performance of each final model was evaluated according to correlation coefficient (Rp) and root mean square error of prediction (RMSEP) in prediction set. Si-BP-AdaBoost showed excellent performance in comparison with other models. The best Si-BP-AdaBoost model was achieved with Rp = 0.9180 and RMSEP = 2.23 in the prediction set. It was concluded that NIR spectroscopy combined with Si-BP-AdaBoost was an appropriate method for the prediction of the sensory quality in Chinese rice wine.

  3. ADAPTATION AND ADAPTABILITY, THE BELLEFAIRE FOLLOWUP STUDY.

    ERIC Educational Resources Information Center

    ALLERHAND, MELVIN E.; AND OTHERS

    A RESEARCH TEAM STUDIED INFLUENCES, ADAPTATION, AND ADAPTABILITY IN 50 POORLY ADAPTING BOYS AT BELLEFAIRE, A REGIONAL CHILD CARE CENTER FOR EMOTIONALLY DISTURBED CHILDREN. THE TEAM ATTEMPTED TO GAUGE THE SUCCESS OF THE RESIDENTIAL TREATMENT CENTER IN TERMS OF THE PSYCHOLOGICAL PATTERNS AND ROLE PERFORMANCES OF THE BOYS DURING INDIVIDUAL CASEWORK…

  4. Heterologous Prime-Boost HIV-1 Vaccination Regimens in Pre-Clinical and Clinical Trials

    PubMed Central

    Brown, Scott A.; Surman, Sherri L.; Sealy, Robert; Jones, Bart G.; Slobod, Karen S.; Branum, Kristen; Lockey, Timothy D.; Howlett, Nanna; Freiden, Pamela; Flynn, Patricia; Hurwitz, Julia L.

    2010-01-01

    Currently, there are more than 30 million people infected with HIV-1 and thousands more are infected each day. Vaccination is the single most effective mechanism for prevention of viral disease, and after more than 25 years of research, one vaccine has shown somewhat encouraging results in an advanced clinical efficacy trial. A modified intent-to-treat analysis of trial results showed that infection was approximately 30% lower in the vaccine group compared to the placebo group. The vaccine was administered using a heterologous prime-boost regimen in which both target antigens and delivery vehicles were changed during the course of inoculations. Here we examine the complexity of heterologous prime-boost immunizations. We show that the use of different delivery vehicles in prime and boost inoculations can help to avert the inhibitory effects caused by vector-specific immune responses. We also show that the introduction of new antigens into boost inoculations can be advantageous, demonstrating that the effect of ‘original antigenic sin’ is not absolute. Pre-clinical and clinical studies are reviewed, including our own work with a three-vector vaccination regimen using recombinant DNA, virus (Sendai virus or vaccinia virus) and protein. Promising preliminary results suggest that the heterologous prime-boost strategy may possibly provide a foundation for the future prevention of HIV-1 infections in humans. PMID:20407589

  5. Application of Boosting Regression Trees to Preliminary Cost Estimation in Building Construction Projects.

    PubMed

    Shin, Yoonseok

    2015-01-01

    Among the recent data mining techniques available, the boosting approach has attracted a great deal of attention because of its effective learning algorithm and strong boundaries in terms of its generalization performance. However, the boosting approach has yet to be used in regression problems within the construction domain, including cost estimations, but has been actively utilized in other domains. Therefore, a boosting regression tree (BRT) is applied to cost estimations at the early stage of a construction project to examine the applicability of the boosting approach to a regression problem within the construction domain. To evaluate the performance of the BRT model, its performance was compared with that of a neural network (NN) model, which has been proven to have a high performance in cost estimation domains. The BRT model has shown results similar to those of NN model using 234 actual cost datasets of a building construction project. In addition, the BRT model can provide additional information such as the importance plot and structure model, which can support estimators in comprehending the decision making process. Consequently, the boosting approach has potential applicability in preliminary cost estimations in a building construction project. PMID:26339227

  6. Comprehensive review of high power factor ac-dc boost converters for PFC applications

    NASA Astrophysics Data System (ADS)

    De Castro Pereira, Dênis; Da Silva, Márcio Renato; Mateus Silva, Elder; Lessa Tofoli, Fernando

    2015-08-01

    High power factor rectifiers have been consolidated as an effective solution to improve power quality indices in terms of input power factor correction, reduction in the total harmonic distortion of the input current and also regulated dc voltages. Within this context, this subject has motivated the introduction of numerous converter topologies based on classic dc-dc structures associated with novel control techniques, thus leading to the manufacturing of dedicated integrated circuits that allow high input power factor by adding a front-end stage to switch-mode converters. In particular, boost converters in continuous current mode (CCM) are widely employed since they allow obtaining minimised electromagnetic interference levels. This work is concerned with a literature review involving relevant ac-dc single-phase boost-based topologies with high input power factor. The evolution of aspects regarding the conventional boost converter is shown in terms of improved characteristics inherent to other ac-dc boost converters. Additionally, the work intends to be a fast and concise reference to single-phase ac-dc boost converters operating in CCM for engineers, researchers and experts in the field of power electronics by properly analysing and comparing the aforementioned rectifiers.

  7. HIV-1 sub-type C chimaeric VLPs boost cellular immune responses in mice

    PubMed Central

    2010-01-01

    Several approaches have been explored to eradicate HIV; however, a multigene vaccine appears to be the best option, given their proven potential to elicit broad, effective responses in animal models. The Pr55Gag protein is an excellent vaccine candidate in its own right, given that it can assemble into large, enveloped, virus-like particles (VLPs) which are highly immunogenic, and can moreover be used as a scaffold for the presentation of other large non-structural HIV antigens. In this study, we evaluated the potential of two novel chimaeric HIV-1 Pr55Gag-based VLP constructs - C-terminal fusions with reverse transcriptase and a Tat::Nef fusion protein, designated GagRT and GagTN respectively - to enhance a cellular response in mice when used as boost components in two types of heterologous prime-boost vaccine strategies. A vaccine regimen consisting of a DNA prime and chimaeric HIV-1 VLP boosts in mice induced strong, broad cellular immune responses at an optimum dose of 100 ng VLPs. The enhanced cellular responses induced by the DNA prime-VLP boost were two- to three-fold greater than two DNA vaccinations. Moreover, a mixture of GagRT and GagTN VLPs also boosted antigen-specific CD8+ and CD4+ T-cell responses, while VLP vaccinations only induced predominantly robust Gag CD4+ T-cell responses. The results demonstrate the promising potential of these chimaeric VLPs as vaccine candidates against HIV-1. PMID:21087527

  8. Application of Boosting Regression Trees to Preliminary Cost Estimation in Building Construction Projects.

    PubMed

    Shin, Yoonseok

    2015-01-01

    Among the recent data mining techniques available, the boosting approach has attracted a great deal of attention because of its effective learning algorithm and strong boundaries in terms of its generalization performance. However, the boosting approach has yet to be used in regression problems within the construction domain, including cost estimations, but has been actively utilized in other domains. Therefore, a boosting regression tree (BRT) is applied to cost estimations at the early stage of a construction project to examine the applicability of the boosting approach to a regression problem within the construction domain. To evaluate the performance of the BRT model, its performance was compared with that of a neural network (NN) model, which has been proven to have a high performance in cost estimation domains. The BRT model has shown results similar to those of NN model using 234 actual cost datasets of a building construction project. In addition, the BRT model can provide additional information such as the importance plot and structure model, which can support estimators in comprehending the decision making process. Consequently, the boosting approach has potential applicability in preliminary cost estimations in a building construction project.

  9. Adaptive Image Denoising by Mixture Adaptation

    NASA Astrophysics Data System (ADS)

    Luo, Enming; Chan, Stanley H.; Nguyen, Truong Q.

    2016-10-01

    We propose an adaptive learning procedure to learn patch-based image priors for image denoising. The new algorithm, called the Expectation-Maximization (EM) adaptation, takes a generic prior learned from a generic external database and adapts it to the noisy image to generate a specific prior. Different from existing methods that combine internal and external statistics in ad-hoc ways, the proposed algorithm is rigorously derived from a Bayesian hyper-prior perspective. There are two contributions of this paper: First, we provide full derivation of the EM adaptation algorithm and demonstrate methods to improve the computational complexity. Second, in the absence of the latent clean image, we show how EM adaptation can be modified based on pre-filtering. Experimental results show that the proposed adaptation algorithm yields consistently better denoising results than the one without adaptation and is superior to several state-of-the-art algorithms.

  10. Multivariate Boosting for Integrative Analysis of High-Dimensional Cancer Genomic Data

    PubMed Central

    Xiong, Lie; Kuan, Pei-Fen; Tian, Jianan; Keles, Sunduz; Wang, Sijian

    2015-01-01

    In this paper, we propose a novel multivariate component-wise boosting method for fitting multivariate response regression models under the high-dimension, low sample size setting. Our method is motivated by modeling the association among different biological molecules based on multiple types of high-dimensional genomic data. Particularly, we are interested in two applications: studying the influence of DNA copy number alterations on RNA transcript levels and investigating the association between DNA methylation and gene expression. For this purpose, we model the dependence of the RNA expression levels on DNA copy number alterations and the dependence of gene expression on DNA methylation through multivariate regression models and utilize boosting-type method to handle the high dimensionality as well as model the possible nonlinear associations. The performance of the proposed method is demonstrated through simulation studies. Finally, our multivariate boosting method is applied to two breast cancer studies. PMID:26609213

  11. Numerical study of ultra-relativistic electromagnetic filamentation in boosted frames

    NASA Astrophysics Data System (ADS)

    Martins, S. F.; Fonseca, R. A.; Mori, W. B.; Silva, L. O.

    2007-11-01

    We address the simulation of relativistic shocks in astrophysics, namely the numerical implications of ultra-relativistic particles and the large time/space scales associated with these systems. It was recently shown [1] that performing simulations in optimized Lorentz frames can decrease simulation run times by orders of magnitude, completely changing computational resources required. The Lorentz transformation for a boosted frame was implemented in osiris 2.0 [2] and encompassed several difficulties that will be discussed. For instance, transformation of quantities back to the laboratory frame may require massive data handling and complex diagnostic/visualization, and can cancel the potential gains from the time scale reduction due to the boost. The possibility of using a boosted frame to suppress numerical noise (e.g. due to numerical Cerenkov radiation) will also be explored. [1] J.-L. Vay, PRL 98, 130405 (2007) [2] R. A. Fonseca et al, Lecture Notes in Computer Science 2329, III-342 (Springer-Verlag, 2002)

  12. An evaluation of a hubless inducer and a full flow hydraulic turbine driven inducer boost pump

    NASA Technical Reports Server (NTRS)

    Lindley, B. K.; Martinson, A. R.

    1971-01-01

    The purpose of the study was to compare the performance of several configurations of hubless inducers with a hydrodynamically similar conventional inducer and to demonstrate the performance of a full flow hydraulic turbine driven inducer boost pump using these inducers. A boost pump of this type consists of an inducer connected to a hydraulic turbine with a high speed rotor located in between. All the flow passes through the inducer, rotor, and hydraulic turbine, then into the main pump. The rotor, which is attached to the main pump shaft, provides the input power to drive the hydraulic turbine which, in turn, drives the inducer. The inducer, rotating at a lower speed, develops the necessary head to prevent rotor cavitation. The rotor speed is consistent with present main engine liquid hydrogen pump designs and the overall boost pump head rise is sufficient to provide adequate main pump suction head. This system would have the potential for operating at lower liquid hydrogen tank pressures.

  13. Targeted intraoperative radiotherapy (TARGIT) yields very low recurrence rates when given as a boost

    SciTech Connect

    Vaidya, Jayant S. . E-mail: j.s.vaidya@dundee.ac.uk; Baum, Michael; Tobias, Jeffrey S.; Massarut, Samuele; Wenz, Frederik; Murphy, Olive; Hilaris, Basil; Houghton, Joan B.Sc.; Saunders, Christobel; Corica, Tammy; Roncadin, Mario; Kraus-Tiefenbacher, Uta; Melchaert, Frank; Keshtgar, Mohammed; Sainsbury, Richard; Douek, Michael; Harrison, Elly; Thompson, Alastair; Joseph, David

    2006-12-01

    Purpose: Patients undergoing breast-conserving surgery were offered boost radiotherapy with targeted intraoperative radiotherapy (TARGIT) using the Intrabeam system to test the feasibility, safety, and efficacy of the new approach. Methods and Materials: We treated 302 cancers in 301 unselected patients. This was not a low-risk group. One-third of patients (98/301) were younger than 51 years of age. More than half of the tumors (172, 57%) were between 1 cm and 2 cm, and one-fifth (62, 21%) were >2 cm; 29% (86) had a Grade 3 tumor and, in 29% (87), axillary lymph nodes contained metastasis. After primary surgery, 20 Gy was delivered intraoperatively to the surface of the tumor bed, followed by external-beam radiotherapy (EBRT), but excluding the usual boost. Results: The treatment was well tolerated. The follow-up ranged from 3 to 80 months (164 and 90 patients completed 2 and 3 years follow-up, respectively). Four patients (1.3%) had local recurrence. The Kaplan-Meier estimate of local recurrence is 2.6% (SE = 1.7) at 5 years. This compares favorably with the 4.3% recurrence rate in boosted patients from the EORTC boost study, in which only 8.1% patients were node-positive, as opposed to 29% in our series. Conclusion: Targeted intraoperative radiotherapy combined with EBRT results in a low local recurrence rate. This could be attributed to both accurate targeting and timeliness of the treatment. These data support the need for a randomized trial to test whether the TARGIT boost is superior to conventional external boost, especially in high-risk women.

  14. Positive Surgical Margins in Soft Tissue Sarcoma Treated With Preoperative Radiation: Is a Postoperative Boost Necessary?

    SciTech Connect

    Al Yami, Ali; Griffin, Anthony M.; Ferguson, Peter C.; Catton, Charles N.; Chung, Peter W.M.

    2010-07-15

    Purpose: For patients with an extremity soft tissue sarcoma (STS) treated with preoperative radiotherapy and surgically excised with positive margins, we retrospectively reviewed whether a postoperative radiation boost reduced the risk of local recurrence (LR). Methods and Materials: A total of 216 patients with positive margins after resection of an extremity STS treated between 1986 and 2003 were identified from our institution's prospectively collected database. Patient demographics, radiation therapy parameters including timing and dose, classification of positive margin status, reasons for not administering a postoperative boost, and oncologic outcome were collected and evaluated. Results: Of the 216 patients with a positive surgical margin, 52 patients were treated with preoperative radiation therapy alone (50 Gy), whereas 41 received preoperative radiation therapy plus a postoperative boost (80% received 16 Gy postoperatively for a total of 66 Gy). There was no difference in baseline tumor characteristics between the two groups. Six of 52 patients in the group receiving preoperative radiation alone developed a LR compared with 9 of 41 in the boost group. Five-year estimated LR-free survivals were 90.4% and 73.8%, respectively (p = 0.13). Conclusions: We found that including the postoperative radiation boost after preoperative radiation and a margin-positive excision did not provide an advantage in preventing LR for patients treated with external beam radiotherapy. Given that higher radiation doses placed patients at greater risk for late complications such as fracture, fibrosis, edema, and joint stiffness, judicious avoidance of the postoperative boost while maintaining an equivalent rate of local control can reduce the risk of these difficult-to-treat morbidities.

  15. Dosimetric evaluation of simultaneous integrated boost during stereotactic body radiation therapy for pancreatic cancer

    SciTech Connect

    Yang, Wensha; Reznik, Robert; Fraass, Benedick A.; Nissen, Nicholas; Hendifar, Andrew; Wachsman, Ashley; Sandler, Howard; Tuli, Richard

    2015-04-01

    Stereotactic body radiation therapy (SBRT) provides a promising way to treat locally advanced pancreatic cancer and borderline resectable pancreatic cancer. A simultaneous integrated boost (SIB) to the region of vessel abutment or encasement during SBRT has the potential to downstage otherwise likely positive surgical margins. Despite the potential benefit of using SIB-SBRT, the ability to boost is limited by the local geometry of the organs at risk (OARs), such as stomach, duodenum, and bowel (SDB), relative to tumor. In this study, we have retrospectively replanned 20 patients with 25 Gy prescribed to the planning target volume (PTV) and 33~80 Gy to the boost target volume (BTV) using an SIB technique for all patients. The number of plans and patients able to satisfy a set of clinically established constraints is analyzed. The ability to boost vessels (within the gross target volume [GTV]) is shown to correlate with the overlap volume (OLV), defined to be the overlap between the GTV + a 1(OLV1)- or 2(OLV2)-cm margin with the union of SDB. Integral dose, boost dose contrast (BDC), biologically effective BDC, tumor control probability for BTV, and normal tissue complication probabilities are used to analyze the dosimetric results. More than 65% of the cases can deliver a boost to 40 Gy while satisfying all OAR constraints. An OLV2 of 100 cm{sup 3} is identified as the cutoff volume: for cases with OLV2 larger than 100 cm{sup 3}, it is very unlikely the case could achieve 25 Gy to the PTV while successfully meeting all the OAR constraints.

  16. Long-Term Results of Targeted Intraoperative Radiotherapy (Targit) Boost During Breast-Conserving Surgery

    SciTech Connect

    Vaidya, Jayant S.; Baum, Michael; Tobias, Jeffrey S.; Wenz, Frederik; Massarut, Samuele; Keshtgar, Mohammed; Hilaris, Basil; Saunders, Christobel; Williams, Norman R.; Brew-Graves, Chris; Corica, Tammy; Roncadin, Mario; Kraus-Tiefenbacher, Uta; Suetterlin, Marc; Bulsara, Max; Joseph, David

    2011-11-15

    Purpose: We have previously shown that delivering targeted radiotherapy to the tumour bed intraoperatively is feasible and desirable. In this study, we report on the feasibility, safety, and long-term efficacy of TARGeted Intraoperative radioTherapy (Targit), using the Intrabeam system. Methods and Materials: A total of 300 cancers in 299 unselected patients underwent breast-conserving surgery and Targit as a boost to the tumor bed. After lumpectomy, a single dose of 20 Gy was delivered intraoperatively. Postoperative external beam whole-breast radiotherapy excluded the usual boost. We also performed a novel individualized case control (ICC) analysis that computed the expected recurrences for the cohort by estimating the risk of recurrence for each patient using their characteristics and follow-up period. Results: The treatment was well tolerated. The median follow up was 60.5 months (range, 10-122 months). Eight patients have had ipsilateral recurrence: 5-year Kaplan Meier estimate for ipsilateral recurrence is 1.73% (SE 0.77), which compares well with that seen in the boosted patients in the European Organization for Research and Treatment of Cancer study (4.3%) and the UK STAndardisation of breast RadioTherapy study (2.8%). In a novel ICC analysis of 242 of the patients, we estimated that there should be 11.4 recurrences; in this group, only 6 recurrences were observed. Conclusions: Lumpectomy and Targit boost combined with external beam radiotherapy results in a low local recurrence rate in a standard risk patient population. Accurate localization and the immediacy of the treatment that has a favorable effect on tumour microenvironment may contribute to this effect. These long-term data establish the long-term safety and efficacy of the Targit technique and generate the hypothesis that Targit boost might be superior to an external beam boost in its efficacy and justifies a randomized trial.

  17. A planning study of simultaneous integrated boost with forward IMRT for multiple brain metastases

    SciTech Connect

    Liang, Xiaodong; Ni, Lingqin; Hu, Wei; Chen, Weijun; Ying, Shenpeng; Gong, Qiangjun; Liu, Yanmei

    2013-07-01

    The objective of this study was to evaluate the dose conformity and feasibility of whole-brain radiotherapy with a simultaneous integrated boost by forward intensity-modulated radiation therapy in patients with 1 to 3 brain metastases. Forward intensity-modulated radiation therapy plans were generated for 10 patients with 1 to 3 brain metastases on Pinnacle 6.2 Treatment Planning System. The prescribed dose was 30 Gy to the whole brain (planning target volume [PTV]{sub wbrt}) and 40 Gy to individual brain metastases (PTV{sub boost}) simultaneously, and both doses were given in 10 fractions. The maximum diameters of individual brain metastases ranged from 1.6 to 6 cm, and the summated PTVs per patient ranged from 1.62 to 69.81 cm{sup 3}. Conformity and feasibility were evaluated regarding conformation number and treatment delivery time. One hundred percent volume of the PTV{sub boost} received at least 95% of the prescribed dose in all cases. The maximum doses were less than 110% of the prescribed dose to the PTV{sub boost}, and all of the hot spots were within the PTV{sub boost}. The volume of the PTV{sub wbrt} that received at least 95% of the prescribed dose ranged from 99.2% to 100%. The mean values of conformation number were 0.682. The mean treatment delivery time was 2.79 minutes. Ten beams were used on an average in these plans. Whole-brain radiotherapy with a simultaneous integrated boost by forward intensity-modulated radiation therapy in 1 to 3 brain metastases is feasible, and treatment delivery time is short.

  18. Fission dynamics within time-dependent Hartree-Fock. II. Boost-induced fission

    NASA Astrophysics Data System (ADS)

    Goddard, Philip; Stevenson, Paul; Rios, Arnau

    2016-01-01

    Background: Nuclear fission is a complex large-amplitude collective decay mode in heavy nuclei. Microscopic density functional studies of fission have previously concentrated on adiabatic approaches based on constrained static calculations ignoring dynamical excitations of the fissioning nucleus and the daughter products. Purpose: We explore the ability of dynamic mean-field methods to describe induced fission processes, using quadrupole boosts in the nuclide 240Pu as an example. Methods: Following upon the work presented in Goddard et al. [Phys. Rev. C 92, 054610 (2015)], 10.1103/PhysRevC.92.054610, quadrupole-constrained Hartree-Fock calculations are used to create a potential energy surface. An isomeric state and a state beyond the second barrier peak are excited by means of instantaneous as well as temporally extended gauge boosts with quadrupole shapes. The subsequent deexcitation is studied in a time-dependent Hartree-Fock simulation, with emphasis on fissioned final states. The corresponding fission fragment mass numbers are studied. Results: In general, the energy deposited by the quadrupole boost is quickly absorbed by the nucleus. In instantaneous boosts, this leads to fast shape rearrangements and violent dynamics that can ultimately lead to fission. This is a qualitatively different process than the deformation-induced fission. Boosts induced within a finite time window excite the system in a relatively gentler way and do induce fission but with a smaller energy deposition. Conclusions: The fission products obtained using boost-induced fission in time-dependent Hartree-Fock are more asymmetric than the fragments obtained in deformation-induced fission or the corresponding adiabatic approaches.

  19. Boosted objects and jet substructure at the LHC: Report of BOOST2012, held at IFIC Valencia, 23rd-27th of July 2012

    DOE PAGES

    Altheimer, A.

    2014-03-21

    This report of the BOOST2012 workshop presents the results of four working groups that studied key aspects of jet substructure. We discuss the potential of first-principle QCD calculations to yield a precise description of the substructure of jets and study the accuracy of state-of-the-art Monte Carlo tools. Limitations of the experiments’ ability to resolve substructure are evaluated, with a focus on the impact of additional (pile-up) proton proton collisions on jet substructure performance in future LHC operating scenarios. The final section summarizes the lessons learnt from jet substructure analyses in searches for new physics in the production of boosted topmore » quarks.« less

  20. Using machine learning to predict gene expression and discover sequence motifs

    NASA Astrophysics Data System (ADS)

    Li, Xuejing

    Recently, large amounts of experimental data for complex biological systems have become available. We use tools and algorithms from machine learning to build data-driven predictive models. We first present a novel algorithm to discover gene sequence motifs associated with temporal expression patterns of genes. Our algorithm, which is based on partial least squares (PLS) regression, is able to directly model the flow of information, from gene sequence to gene expression, to learn cis regulatory motifs and characterize associated gene expression patterns. Our algorithm outperforms traditional computational methods e.g. clustering in motif discovery. We then present a study of extending a machine learning model for transcriptional regulation predictive of genetic regulatory response to Caenorhabditis elegans. We show meaningful results both in terms of prediction accuracy on the test experiments and biological information extracted from the regulatory program. The model discovers DNA binding sites ab initio. We also present a case study where we detect a signal of lineage-specific regulation. Finally we present a comparative study on learning predictive models for motif discovery, based on different boosting algorithms: Adaptive Boosting (AdaBoost), Linear Programming Boosting (LPBoost) and Totally Corrective Boosting (TotalBoost). We evaluate and compare the performance of the three boosting algorithms via both statistical and biological validation, for hypoxia response in Saccharomyces cerevisiae.

  1. Boosted and Linked Mixtures of HMMs for Brain-Machine Interfaces

    NASA Astrophysics Data System (ADS)

    Darmanjian, Shalom; Principe, Jose C.

    2008-12-01

    We propose two algorithms that decompose the joint likelihood of observing multidimensional neural input data into marginal likelihoods. The first algorithm, boosted mixtures of hidden Markov chains (BMs-HMM), applies techniques from boosting to create implicit hierarchic dependencies between these marginal subspaces. The second algorithm, linked mixtures of hidden Markov chains (LMs-HMM), uses a graphical modeling framework to explicitly create the hierarchic dependencies between these marginal subspaces. Our results show that these algorithms are very simple to train and computationally efficient, while also reducing the input dimensionality for brain-machine interfaces (BMIs).

  2. Analysis of high voltage step-up nonisolated DC-DC boost converters

    NASA Astrophysics Data System (ADS)

    Alisson Alencar Freitas, Antônio; Lessa Tofoli, Fernando; Junior, Edilson Mineiro Sá; Daher, Sergio; Antunes, Fernando Luiz Marcelo

    2016-05-01

    A high voltage step-up nonisolated DC-DC converter based on coupled inductors suitable to photovoltaic (PV) systems applications is proposed in this paper. Considering that numerous approaches exist to extend the voltage conversion ratio of DC-DC converters that do not use transformers, a detailed comparison is also presented among the proposed converter and other popular topologies such as the conventional boost converter and the quadratic boost converter. The qualitative analysis of the coupled-inductor-based topology is developed so that a design procedure can be obtained, from which an experimental prototype is implemented to validate the theoretical assumptions.

  3. PWM Technique for Non-Isolated Three-Phase Buck-Boost PFC Converter

    NASA Astrophysics Data System (ADS)

    Morizane, Toshimitsu; Shimomori, Wataru; Taniguchi, Katsunori; Kimura, Noriyuki; Ogawa, Masanori

    The buck-boost power factor corrected (PFC) converter has the wide range of the dc output voltage. A new non-isolated three-phase hard-switching and a soft-switching buck-boost PFC converter are proposed. Removing the three-phase transformer from the converters makes their size more compact and their costs lower. In addition, the new control method based on the PWM technique is proposed in this paper to achieve the high power factor. Complete soft-switching is also achieved under the discontinuous current mode (DCM) operation.

  4. Optimization of control parameters of a boost converter for energy harvesting

    NASA Astrophysics Data System (ADS)

    Tanaka, M.; Hemthavy, P.; Takahashi, K.

    2012-08-01

    In order to maximize the energy efficiency for energy harvesting, a simplified circuit model using a boost converter and a capacitor is proposed. The circuit model allows the analysis of the whole system's theoretical energy efficiency and determination of the optimum control parameters. The optimum duty ratio is determined analytically and the optimum switching period numerically. This is important information for designing a switching controller that achieves both low power consumption and accurate maximum power point tracking. Moreover, the proposed theoretical energy efficiency is helpful for component selection when designing boost converters.

  5. Boost Converters for Gas Electric and Fuel Cell Hybrid Electric Vehicles

    SciTech Connect

    McKeever, JW

    2005-06-16

    Hybrid electric vehicles (HEVs) are driven by at least two prime energy sources, such as an internal combustion engine (ICE) and propulsion battery. For a series HEV configuration, the ICE drives only a generator, which maintains the state-of-charge (SOC) of propulsion and accessory batteries and drives the electric traction motor. For a parallel HEV configuration, the ICE is mechanically connected to directly drive the wheels as well as the generator, which likewise maintains the SOC of propulsion and accessory batteries and drives the electric traction motor. Today the prime energy source is an ICE; tomorrow it will very likely be a fuel cell (FC). Use of the FC eliminates a direct drive capability accentuating the importance of the battery charge and discharge systems. In both systems, the electric traction motor may use the voltage directly from the batteries or from a boost converter that raises the voltage. If low battery voltage is used directly, some special control circuitry, such as dual mode inverter control (DMIC) which adds a small cost, is necessary to drive the electric motor above base speed. If high voltage is chosen for more efficient motor operation or for high speed operation, the propulsion battery voltage must be raised, which would require some type of two-quadrant bidirectional chopper with an additional cost. Two common direct current (dc)-to-dc converters are: (1) the transformer-based boost or buck converter, which inverts a dc voltage, feeds the resulting alternating current (ac) into a transformer to raise or lower the voltage, and rectifies it to complete the conversion; and (2) the inductor-based switch mode boost or buck converter [1]. The switch-mode boost and buck features are discussed in this report as they operate in a bi-directional chopper. A benefit of the transformer-based boost converter is that it isolates the high voltage from the low voltage. Usually the transformer is large, further increasing the cost. A useful feature

  6. Role of Brachytherapy in the Boost Management of Anal Carcinoma With Node Involvement (CORS-03 Study)

    SciTech Connect

    Moureau-Zabotto, Laurence; Ortholan, Cecile; Hannoun-Levi, Jean-Michel; Teissier, Eric; Cowen, Didier; Salem, Nagi; Lemanski, Claire; Ellis, Steve; Resbeut, Michel

    2013-03-01

    Purpose: To assess retrospectively the clinical outcome in anal cancer patients, with lymph node involvement, treated with split-course radiation therapy and receiving a boost through external beam radiation therapy (EBRT) or brachytherapy (BCT). Methods and Materials: From 2000 to 2005, among 229 patients with invasive nonmetastatic anal squamous cell carcinoma, a selected group of 99 patients, with lymph node involvement, was studied. Tumor staging reported was T1 in 4 patients, T2 in 16 patients, T3 in 49 patients, T4 in 16 patients, and T unknown in 14 patients and as N1 in 67 patients and N2/N3 in 32 patients. Patients underwent a first course of EBRT (mean dose, 45.1 Gy) followed by a boost (mean dose, 18 Gy) using EBRT (50 patients) or BCT (49 patients). All characteristics of patients and tumors were well balanced between the BCT and EBRT groups. Prognostic factors of cumulative rate of local recurrence (CRLR), cumulative rate of distant (including nodal) recurrence (CRDR), colostomy-free survival (CFS) rate, and overall survival (OS) rate were analyzed for the overall population and according to the nodal status classification. Results: The median follow-up was 71.5 months. The 5-year CRLR, CRDR, CFS rate, and OS rate were 21%, 19%, 63%, and 74.4%, respectively. In the overall population, the type of node involvement (N1 vs N2/N3) was the unique independent prognostic factor for CRLR. In N1 patients, by use of multivariate analysis, BCT boost was the unique prognostic factor for CRLR (4% for BCT vs 31% for EBRT; hazard ratio, 0.08; P=.042). No studied factors were significantly associated with CRDR, CFS, and OS. No difference with regard to boost technique and any other factor studied was observed in N2/N3 patients for any kind of recurrence. Conclusion: In anal cancer, even in the case of initial perirectal node invasion, BCT boost is superior to EBRT boost for CRLR, without an influence on OS, suggesting that N1 status should not be a contraindication to

  7. Gua Sha, a press-stroke treatment of the skin, boosts the immune response to intradermal vaccination

    PubMed Central

    Liu, Jinxuan; Zhang, Xiaoying; Huang, Zhen; Zang, Yuhui; Chen, Jiangning; Dong, Lei

    2016-01-01

    Objective The skin is an important immunological barrier of the body as well as an optimal route for vaccine administration. Gua Sha, which involves press-stroke treatment of the skin, is an effective folk therapy, widely accepted in East Asia, for various symptoms; however, the mechanisms underlying its therapeutic effects have not been clarified. We investigated the influence of Gua Sha on the immunological features of the skin. Methods Gua Sha was performed on BALB/c mice and the effects were evaluated using anatomical, histological, and cytometric methods as well as cytokine determination locally and systemically. The effect on intradermal vaccination was assessed with antigen-specific subtype antibody responses. Results Blood vessel expansion, erythrocyte extravasation, and increased ratios of immune active cells were observed in the skin tissue following the treatment. Pro-inflammatory cytokines were up-regulated, and immunosuppressive cytokines, down-regulated, in the treated and untreated skin and systemic circulation; no obvious variations were detected in case of anti-inflammatory cytokines. Interestingly, intradermal delivery of a model vaccine following Gua Sha induced about three-fold higher IgG titers with a more Th1-biased antibody subtype profile. Conclusion Gua Sha treatment can up-regulate the innate and adaptive immune functions of the skin and boost the response against intradermal antigens. Thus, Gua Sha may serve as a safe, inexpensive, and independent physical adjuvant for intradermal vaccination. PMID:27672506

  8. Gua Sha, a press-stroke treatment of the skin, boosts the immune response to intradermal vaccination

    PubMed Central

    Liu, Jinxuan; Zhang, Xiaoying; Huang, Zhen; Zang, Yuhui; Chen, Jiangning; Dong, Lei

    2016-01-01

    Objective The skin is an important immunological barrier of the body as well as an optimal route for vaccine administration. Gua Sha, which involves press-stroke treatment of the skin, is an effective folk therapy, widely accepted in East Asia, for various symptoms; however, the mechanisms underlying its therapeutic effects have not been clarified. We investigated the influence of Gua Sha on the immunological features of the skin. Methods Gua Sha was performed on BALB/c mice and the effects were evaluated using anatomical, histological, and cytometric methods as well as cytokine determination locally and systemically. The effect on intradermal vaccination was assessed with antigen-specific subtype antibody responses. Results Blood vessel expansion, erythrocyte extravasation, and increased ratios of immune active cells were observed in the skin tissue following the treatment. Pro-inflammatory cytokines were up-regulated, and immunosuppressive cytokines, down-regulated, in the treated and untreated skin and systemic circulation; no obvious variations were detected in case of anti-inflammatory cytokines. Interestingly, intradermal delivery of a model vaccine following Gua Sha induced about three-fold higher IgG titers with a more Th1-biased antibody subtype profile. Conclusion Gua Sha treatment can up-regulate the innate and adaptive immune functions of the skin and boost the response against intradermal antigens. Thus, Gua Sha may serve as a safe, inexpensive, and independent physical adjuvant for intradermal vaccination.

  9. Asymmetric Power Boosts Extortion in an Economic Experiment

    PubMed Central

    Hagel, Kristin; Milinski, Manfred

    2016-01-01

    Direct reciprocity is a major mechanism for the evolution of cooperation. Several classical studies have suggested that humans should quickly learn to adopt reciprocal strategies to establish mutual cooperation in repeated interactions. On the other hand, the recently discovered theory of ZD strategies has found that subjects who use extortionate strategies are able to exploit and subdue cooperators. Although such extortioners have been predicted to succeed in any population of adaptive opponents, theoretical follow-up studies questioned whether extortion can evolve in reality. However, most of these studies presumed that individuals have similar strategic possibilities and comparable outside options, whereas asymmetries are ubiquitous in real world applications. Here we show with a model and an economic experiment that extortionate strategies readily emerge once subjects differ in their strategic power. Our experiment combines a repeated social dilemma with asymmetric partner choice. In our main treatment there is one randomly chosen group member who is unilaterally allowed to exchange one of the other group members after every ten rounds of the social dilemma. We find that this asymmetric replacement opportunity generally promotes cooperation, but often the resulting payoff distribution reflects the underlying power structure. Almost half of the subjects in a better strategic position turn into extortioners, who quickly proceed to exploit their peers. By adapting their cooperation probabilities consistent with ZD theory, extortioners force their co-players to cooperate without being similarly cooperative themselves. Comparison to non-extortionate players under the same conditions indicates a substantial net gain to extortion. Our results thus highlight how power asymmetries can endanger mutually beneficial interactions, and transform them into exploitative relationships. In particular, our results indicate that the extortionate strategies predicted from ZD theory

  10. Parenteral adenoviral boost enhances BCG induced protection, but not long term survival in a murine model of bovine TB.

    PubMed

    Kaveh, Daryan A; Garcia-Pelayo, M Carmen; Webb, Paul R; Wooff, Esen E; Bachy, Véronique S; Hogarth, Philip J

    2016-07-25

    Boosting BCG using heterologous prime-boost represents a promising strategy for improved tuberculosis (TB) vaccines, and adenovirus (Ad) delivery is established as an efficacious boosting vehicle. Although studies demonstrate that intranasal administration of Ad boost to BCG offers optimal protection, this is not currently possible in cattle. Using Ad vaccine expressing the mycobacterial antigen TB10.4 (BCG/Ad-TB10.4), we demonstrate, parenteral boost of BCG immunised mice to induce specific CD8(+) IFN-γ producing T cells via synergistic priming of new epitopes. This induces significant improvement in pulmonary protection against Mycobacterium bovis over that provided by BCG when assessed in a standard 4week challenge model. However, in a stringent, year-long survival study, BCG/Ad-TB10.4 did not improve outcome over BCG, which we suggest may be due to the lack of additional memory cells (IL-2(+)) induced by boosting. These data indicate BCG-prime/parenteral-Ad-TB10.4-boost to be a promising candidate, but also highlight the need for further understanding of the mechanisms of T cell priming and associated memory using Ad delivery systems. That we were able to generate significant improvement in pulmonary protection above BCG with parenteral, rather than mucosal administration of boost vaccine is critical; suggesting that the generation of effective mucosal immunity is possible, without the risks and challenges of mucosal administration, but that further work to specifically enhance sustained protective immunity is required.

  11. Expressing Adaptation Strategies Using Adaptation Patterns

    ERIC Educational Resources Information Center

    Zemirline, N.; Bourda, Y.; Reynaud, C.

    2012-01-01

    Today, there is a real challenge to enable personalized access to information. Several systems have been proposed to address this challenge including Adaptive Hypermedia Systems (AHSs). However, the specification of adaptation strategies remains a difficult task for creators of such systems. In this paper, we consider the problem of the definition…

  12. Boosting up JSL Learners' Outside-Class Learning Time with Learning Log System

    ERIC Educational Resources Information Center

    Uosaki, Noriko; Ogata, Hiroaki; Mouri, Kousuke

    2015-01-01

    This paper tackles enhancing outside-class learning of JSL (Japanese as a Second Language) learners. The objective of this study is to examine the effectiveness of our developed learning log system called SCROLL (System for Capturing and Reminding of Learning Log) in terms of boosting up outside-class learning time of JSL learners in Japan. In our…

  13. Copper-boosting compounds: a novel concept for antimycobacterial drug discovery.

    PubMed

    Speer, Alexander; Shrestha, Tej B; Bossmann, Stefan H; Basaraba, Randall J; Harber, Gregory J; Michalek, Suzanne M; Niederweis, Michael; Kutsch, Olaf; Wolschendorf, Frank

    2013-02-01

    We and others recently identified copper resistance as important for virulence of Mycobacterium tuberculosis. Here, we introduce a high-throughput screening assay for agents that induce a copper hypersensitivity phenotype in M. tuberculosis and demonstrate that such copper-boosting compounds are effective against replicating and nonreplicating M. tuberculosis strains.

  14. Historical and Current U.S. Strategies for Boosting Distributed Generation

    SciTech Connect

    Lowder, Travis; Schwabe, Paul; Zhou, Ella; Arent, Douglas J.

    2015-10-29

    This report seeks to introduce a variety of top-down and bottom-up practices that, in concert with the macro-environment of cost-reduction globally and early adoption in Europe, helped boost the distributed generation photovoltaic market in the United States. These experiences may serve as a reference in China's quest to promote distributed renewable energy.

  15. Developing an organisational philosophy to boost service quality and staff morale.

    PubMed

    Ryan, Jo; Park, John

    Responding to complaints, nurses at Yeovil District Hospital led a drive to improve the quality of care for the trust's patients and the engagement of relatives and carers, while at the same time boosting employee morale. Over the past four years this has been achieved by implementing the iCARE philosophy--a new way of working--which operates throughout the trust.

  16. A species of human alpha interferon that lacks the ability to boost human natural killer activity.

    PubMed Central

    Ortaldo, J R; Herberman, R B; Harvey, C; Osheroff, P; Pan, Y C; Kelder, B; Pestka, S

    1984-01-01

    Most species of recombinant leukocyte interferons (IFN-alpha A, -alpha B, -alpha C, -alpha D, -alpha F, -alpha I, and -alpha K) were capable of boosting human natural killer (NK) activity after a 2-hr treatment of cells at a concentration of 1-80 units/ml. In contrast, recombinant human IFN-alpha J was found to be incapable of augmenting NK activity after exposure of cells for 2 hr to concentrations as high as 10,000 units/ml. This inability of IFN-alpha J to boost NK activity was not complete because, after exposure of cells to a high concentration of IFN-alpha J (10,000 units/ml) for 18 hr, boosting of cytolysis was observed. IFN-alpha J appeared to interact with receptors for IFN on NK cells since it was found to interfere with the boosting of NK activity by other species of IFN-alpha. In contrast to its deficient ability to augment NK activity, IFN-alpha J has potent antiviral and antiproliferative activities. Such extensive dissociation of these biological activities has not been observed previously with any other natural or recombinant IFN species. Thus, this IFN species may be useful for evaluating the relative importance of various biological activities on the therapeutic effects of IFN, for understanding structure-function relationships, and for determining the biochemical pathways related to the various biological effects of IFN. PMID:6589637

  17. Detecting Boosted Dark Matter from the Sun with Large Volume Neutrino Detectors

    SciTech Connect

    Berger, Joshua; Cui, Yanou; Zhao, Yue; /Stanford U., ITP /Stanford U., Phys. Dept.

    2015-04-02

    We study novel scenarios where thermal dark matter (DM) can be efficiently captured in the Sun and annihilate into boosted dark matter. In models with semi-annihilating DM, where DM has a non-minimal stabilization symmetry, or in models with a multi-component DM sector, annihilations of DM can give rise to stable dark sector particles with moderate Lorentz boosts. We investigate both of these possibilities, presenting concrete models as proofs of concept. Both scenarios can yield viable thermal relic DM with masses O(1)-O(100) GeV. Taking advantage of the energetic proton recoils that arise when the boosted DM scatters off matter, we propose a detection strategy which uses large volume terrestrial detectors, such as those designed to detect neutrinos or proton decays. In particular, we propose a search for proton tracks pointing towards the Sun. We focus on signals at Cherenkov-radiation-based detectors such as Super-Kamiokande (SK) and its upgrade Hyper-Kamiokande (HK). We find that with spin-dependent scattering as the dominant DM-nucleus interaction at low energies, boosted DM can leave detectable signals at SK or HK, with sensitivity comparable to DM direct detection experiments while being consistent with current constraints. Our study provides a new search path for DM sectors with non-minimal structure.

  18. Can Face-to-Face Mobilization Boost Student Voter Turnout? Results of a Campus Field Experiment

    ERIC Educational Resources Information Center

    Hill, David; Lachelier, Paul

    2014-01-01

    American colleges and universities have an expanding role to play in nurturing political engagement as more youth attend college. Given low voter turnout among college students yet growing experimental evidence that face-to-face mobilization can boost turnout, the experiment reported in this article examined the impact of a face-to-face college…

  19. Boosting Your Science and Math Programs in Early Childhood Education: Making the Home-School Connection.

    ERIC Educational Resources Information Center

    Kokoski, Teresa M.; Downing-Leffler, Nancy

    1995-01-01

    Proposes the home-school connection as a key solution to boost science, mathematics, and technology programs in schools. Suggests that professionals in education must find ways to make connections between school learning and children's learning outside school. Proposes appropriate strategies such as science and mathematics backpacks, minimuseums,…

  20. Boost your bargaining clout in contract negotiations with Medicare managed care plans.

    PubMed

    1999-06-01

    Boost your clout in negotiations with Medicare plans. Find out what Desert Physicians Association in Mesa, AZ, has learned in its dispute over reimbursement rates with CIGNA, and get some advice from a Medicare managed care consultant on how to negotiate contracts with Medicare plans. PMID:10538679

  1. Modelling, simulation and construction of a dc/dc boost power converter: a school experimental system

    NASA Astrophysics Data System (ADS)

    Silva-Ortigoza, R.; Silva-Ortigoza, G.; Hernández-Guzmán, V. M.; Saldaña-González, G.; Marcelino-Aranda, M.; Marciano-Melchor, M.

    2012-05-01

    We introduce a dc/dc boost power converter as a didactic prototype intended to support courses on electric circuit analysis experimentally. The corresponding mathematical model is obtained, the converter is designed and an experimental setup is described, constructed and tested. Simplicity of construction as well as low cost of components renders the feasible introduction of this equipment in undergraduate laboratories.

  2. Evaluating the potential of mycorrhizal fungi to boost yields in field grown leeks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    UMaine Cooperative Extension faculty collaborated with a local organic grower and the USDA-ARS Research Center in Wyndmoor, PA to evaluate the potential of mycorrhizal fungi to boost yields in field grown leeks using both commercially available mycorrhizal inocula and a “farm raised” mycorrhizal ino...

  3. Modelling, Simulation and Construction of a DC/DC Boost Power Converter: A School Experimental System

    ERIC Educational Resources Information Center

    Silva-Ortigoza, R.; Silva-Ortigoza, G.; Hernandez-Guzman, V. M.; Saldana-Gonzalez, G.; Marcelino-Aranda, M.; Marciano-Melchor, M.

    2012-01-01

    We introduce a dc/dc boost power converter as a didactic prototype intended to support courses on electric circuit analysis experimentally. The corresponding mathematical model is obtained, the converter is designed and an experimental setup is described, constructed and tested. Simplicity of construction as well as low cost of components renders…

  4. Research on the Boost of Development on Young Children's Fine Motor by Folk Games

    ERIC Educational Resources Information Center

    Wei, Xia

    2016-01-01

    As Chinese traditional folk culture, folk games have unique educational value which can boost the development of young children's fine motor. Based on previous investigation of fine motor skill of children in Nanchong, Sichuan Province, the researcher chose a middle class in public city kindergarten A with lower survey score as the study object.…

  5. 50 Sure Fire Ideas for Boosting Morale and Creating a Can-Do Culture.

    ERIC Educational Resources Information Center

    Baker, John; And Others

    This three-part pamphlet presents 52 ideas contributed by 19 administrators at California community colleges for boosting the morale and performance of college administrators and staff. Following a list of contributors, the first part provides 39 suggestions for acknowledging contributions and encouraging staff members, including writing short…

  6. Modeling self-priming circuits for dielectric elastomer generators towards optimum voltage boost

    NASA Astrophysics Data System (ADS)

    Zanini, Plinio; Rossiter, Jonathan; Homer, Martin

    2016-04-01

    One of the main challenges for the practical implementation of dielectric elastomer generators (DEGs) is supplying high voltages. To address this issue, systems using self-priming circuits (SPCs) — which exploit the DEG voltage swing to increase its supplied voltage — have been used with success. A self-priming circuit consists of a charge pump implemented in parallel with the DEG circuit. At each energy harvesting cycle, the DEG receives a low voltage input and, through an almost constant charge cycle, generates a high voltage output. SPCs receive the high voltage output at the end of the energy harvesting cycle and supply it back as input for the following cycle, using the DEG as a voltage multiplier element. Although rules for designing self-priming circuits for dielectric elastomer generators exist, they have been obtained from intuitive observation of simulation results and lack a solid theoretical foundation. Here we report the development of a mathematical model to predict voltage boost using self-priming circuits. The voltage on the DEG attached to the SPC is described as a function of its initial conditions, circuit parameters/layout, and the DEG capacitance. Our mathematical model has been validated on an existing DEG implementation from the literature, and successfully predicts the voltage boost for each cycle. Furthermore, it allows us to understand the conditions for the boost to exist, and obtain the design rules that maximize the voltage boost.

  7. Do Vertebrate Gut Metagenomes Confer Rapid Ecological Adaptation?

    PubMed

    Alberdi, Antton; Aizpurua, Ostaizka; Bohmann, Kristine; Zepeda-Mendoza, Marie Lisandra; Gilbert, M Thomas P

    2016-09-01

    During times of rapid environmental change, survival of most vertebrate populations depends on their phenomic plasticity. Although differential gene-expression and post-transcriptional processes of the host genome receive focus as the main molecular mechanisms, growing evidence points to the gut microbiota as a key driver defining hosts' phenotypes. We propose that the plasticity of the gut microbiota might be an essential factor determining phenomic plasticity of vertebrates, and that it might play a pivotal role when vertebrates acclimate and adapt to fast environmental variation. We contemplate some key questions and suggest methodological approaches and experimental designs that can be used to evaluate whether gut microorganisms provide a boost of plasticity to vertebrates' phenomes, thereby increasing their acclimation and adaptation capacity.

  8. Do Vertebrate Gut Metagenomes Confer Rapid Ecological Adaptation?

    PubMed

    Alberdi, Antton; Aizpurua, Ostaizka; Bohmann, Kristine; Zepeda-Mendoza, Marie Lisandra; Gilbert, M Thomas P

    2016-09-01

    During times of rapid environmental change, survival of most vertebrate populations depends on their phenomic plasticity. Although differential gene-expression and post-transcriptional processes of the host genome receive focus as the main molecular mechanisms, growing evidence points to the gut microbiota as a key driver defining hosts' phenotypes. We propose that the plasticity of the gut microbiota might be an essential factor determining phenomic plasticity of vertebrates, and that it might play a pivotal role when vertebrates acclimate and adapt to fast environmental variation. We contemplate some key questions and suggest methodological approaches and experimental designs that can be used to evaluate whether gut microorganisms provide a boost of plasticity to vertebrates' phenomes, thereby increasing their acclimation and adaptation capacity. PMID:27453351

  9. A cosmetic evaluation of breast cancer treatment: A randomized study of radiotherapy boost technique

    SciTech Connect

    Vass, Sylvie . E-mail: sylvie.vass@ssss.gouv.qc.ca; Bairati, Isabelle

    2005-08-01

    Purpose: To compare cosmetic results of two different radiotherapy (RT) boost techniques used in the treatment of breast cancer after whole breast radiotherapy and to identify factors affecting cosmetic outcomes. Methods and Materials: Between 1996 and 1998, 142 patients with Stage I and II breast cancer were treated with breast conservative surgery and adjuvant RT. Patients were then randomly assigned to receive a boost dose of 15 Gy delivered to the tumor bed either by iridium 192, or a combination of photons and electrons. Cosmetic evaluations were done on a 6-month basis, with a final evaluation at 36 months after RT. The evaluations were done using a panel of global and specific subjective scores, a digitized scoring system using the breast retraction assessment (BRA) measurement, and a patient's self-assessment evaluation. As cosmetic results were graded according to severity, the comparison of boost techniques was done using the ordinal logistic regression model. Adjusted odds ratios (OR) and their 95% confidence intervals (CI) are presented. Results: At 36 months of follow-up, there was no significant difference between the two groups with respect to the global subjective cosmetic outcome (OR = 1.40; 95%CI = 0.69-2.85, p = 0.35). Good to excellent scores were observed in 65% of implant patients and 62% of photon/electron patients. At 24 months and beyond, telangiectasia was more severe in the implant group with an OR of 9.64 (95%CI = 4.05-22.92, p < 0.0001) at 36 months. The only variable associated with a worse global cosmetic outcome was the presence of concomitant chemotherapy (OR = 3.87; 95%CI = 1.74-8.62). The BRA value once adjusted for age, concomitant chemotherapy, and boost volume showed a positive association with the boost technique. The BRA value was significantly greater in the implant group (p 0.03). There was no difference in the patient's final self-assessment score between the two groups. Three variables were statistically associated with

  10. Greater effort boosts the affective taste properties of food

    PubMed Central

    Johnson, Alexander W.; Gallagher, Michela

    2011-01-01

    Actions can create preferences, increasing the value ascribed to commodities acquired at greater cost. This behavioural finding has been observed in a variety of species; however, the causal factors underlying the phenomenon are relatively unknown. We sought to develop a behavioural platform to examine the relationship between effort and reinforcer value in mice trained under demanding or lenient schedules of reinforcement to obtain food. In the initial experiment, expenditure of effort enhanced the value of the associated food via relatively lasting changes in its hedonic attributes, promoting an acquired preference for these reinforcers when tested outside of the training environment. Moreover, otherwise neutral cues associated with those reinforcers during training similarly acquired greater reinforcing value, as assessed under conditioned reinforcement. In a separate experiment, expenditure of effort was also capable of enhancing the value of less-preferred low-caloric reinforcers. Analysis of licking microstructure revealed the basis for this increased valuation was, in part, due to increased palatability of the associated reinforcer. This change in the hedonic taste properties of the food can not only serve as a basis for preference, but also guide decision-making and foraging behaviour by coordinating a potentially adaptive repertoire of incentive motivation, goal-directed action and consumption. PMID:21047860

  11. An imaging evaluation of the simultaneously integrated boost breast radiotherapy technique

    SciTech Connect

    Turley, Jessica; Claridge Mackonis, Elizabeth

    2015-09-15

    To evaluate in-field megavoltage (MV) imaging of simultaneously integrated boost (SIB) breast fields to determine its feasibility in treatment verification for the SIB breast radiotherapy technique, and to assess whether the current-imaging protocol and treatment margins are sufficient. For nine patients undergoing SIB breast radiotherapy, in-field MV images of the SIB fields were acquired on days that regular treatment verification imaging was performed. The in-field images were matched offline according to the scar wire on digitally reconstructed radiographs. The offline image correction results were then applied to a margin recipe formula to calculate safe margins that account for random and systematic uncertainties in the position of the boost volume when an offline correction protocol has been applied. After offline assessment of the acquired images, 96% were within the tolerance set in the current department-imaging protocol. Retrospectively performing the maximum position deviations on the Eclipse™ treatment planning system demonstrated that the clinical target volume (CTV) boost received a minimum dose difference of 0.4% and a maximum dose difference of 1.4% less than planned. Furthermore, applying our results to the Van Herk margin formula to ensure that 90% of patients receive 95% of the prescribed dose, the calculated CTV margins were comparable to the current departmental procedure used. Based on the in-field boost images acquired and the feasible application of these results to the margin formula the current CTV-planning target volume margins used are appropriate for the accurate treatment of the SIB boost volume without additional imaging.

  12. Boosting long-term memory via wakeful rest: intentional rehearsal is not necessary, consolidation is sufficient.

    PubMed

    Dewar, Michaela; Alber, Jessica; Cowan, Nelson; Della Sala, Sergio

    2014-01-01

    People perform better on tests of delayed free recall if learning is followed immediately by a short wakeful rest than by a short period of sensory stimulation. Animal and human work suggests that wakeful resting provides optimal conditions for the consolidation of recently acquired memories. However, an alternative account cannot be ruled out, namely that wakeful resting provides optimal conditions for intentional rehearsal of recently acquired memories, thus driving superior memory. Here we utilised non-recallable words to examine whether wakeful rest boosts long-term memory, even when new memories could not be rehearsed intentionally during the wakeful rest delay. The probing of non-recallable words requires a recognition paradigm. Therefore, we first established, via Experiment 1, that the rest-induced boost in memory observed via free recall can be replicated in a recognition paradigm, using concrete nouns. In Experiment 2, participants heard 30 non-recallable non-words, presented as 'foreign names in a bridge club abroad' and then either rested wakefully or played a visual spot-the-difference game for 10 minutes. Retention was probed via recognition at two time points, 15 minutes and 7 days after presentation. As in Experiment 1, wakeful rest boosted recognition significantly, and this boost was maintained for at least 7 days. Our results indicate that the enhancement of memory via wakeful rest is not dependent upon intentional rehearsal of learned material during the rest period. We thus conclude that consolidation is sufficient for this rest-induced memory boost to emerge. We propose that wakeful resting allows for superior memory consolidation, resulting in stronger and/or more veridical representations of experienced events which can be detected via tests of free recall and recognition.

  13. Boosting Long-Term Memory via Wakeful Rest: Intentional Rehearsal Is Not Necessary, Consolidation Is Sufficient

    PubMed Central

    Dewar, Michaela; Alber, Jessica; Cowan, Nelson; Della Sala, Sergio

    2014-01-01

    People perform better on tests of delayed free recall if learning is followed immediately by a short wakeful rest than by a short period of sensory stimulation. Animal and human work suggests that wakeful resting provides optimal conditions for the consolidation of recently acquired memories. However, an alternative account cannot be ruled out, namely that wakeful resting provides optimal conditions for intentional rehearsal of recently acquired memories, thus driving superior memory. Here we utilised non-recallable words to examine whether wakeful rest boosts long-term memory, even when new memories could not be rehearsed intentionally during the wakeful rest delay. The probing of non-recallable words requires a recognition paradigm. Therefore, we first established, via Experiment 1, that the rest-induced boost in memory observed via free recall can be replicated in a recognition paradigm, using concrete nouns. In Experiment 2, participants heard 30 non-recallable non-words, presented as ‘foreign names in a bridge club abroad’ and then either rested wakefully or played a visual spot-the-difference game for 10 minutes. Retention was probed via recognition at two time points, 15 minutes and 7 days after presentation. As in Experiment 1, wakeful rest boosted recognition significantly, and this boost was maintained for at least 7 days. Our results indicate that the enhancement of memory via wakeful rest is not dependent upon intentional rehearsal of learned material during the rest period. We thus conclude that consolidation is sufficient for this rest-induced memory boost to emerge. We propose that wakeful resting allows for superior memory consolidation, resulting in stronger and/or more veridical representations of experienced events which can be detected via tests of free recall and recognition. PMID:25333957

  14. Disease Control and Ototoxicity Using Intensity-Modulated Radiation Therapy Tumor-Bed Boost for Medulloblastoma

    SciTech Connect

    Polkinghorn, William R.; Dunkel, Ira J.; Souweidane, Mark M.; Khakoo, Yasmin; Lyden, David C.; Gilheeney, Stephen W.; Becher, Oren J.; Budnick, Amy S.; Wolden, Suzanne L.

    2011-11-01

    Purpose: We previously reported excellent local control for treating medulloblastoma with a limited boost to the tumor bed. In order to decrease ototoxicity, we subsequently implemented a tumor-bed boost using intensity-modulated radiation therapy (IMRT), the clinical results of which we report here. Patients and Methods: A total of 33 patients with newly diagnosed medulloblastoma, 25 with standard risk, and 8 with high risk, were treated on an IMRT tumor-bed boost following craniospinal irradiation (CSI). Six standard-risk patients were treated with an institutional protocol with 18 Gy CSI in conjunction with intrathecal iodine-131-labeled monoclonal antibody. The majority of patients received concurrent vincristine and standard adjuvant chemotherapy. Pure-tone audiograms were graded according to National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. Results: Median age was 9 years old (range, 4-46 years old). Median follow-up was 63 months. Kaplan-Meier estimates of progression-free survival (PFS) and overall survival (OS) rates for standard-risk patients who received 23.4 or 36 Gy CSI (not including those who received 18 Gy CSI with radioimmunotherapy) were 81.4% and 88.4%, respectively, at 5 years; 5-year PFS and OS rates for high-risk patients were both 87.5%. There were no isolated posterior fossa failures outside of the boost volume. Posttreatment audiograms were available for 31 patients, of whom 6%, at a median follow-up of 19 months, had developed Grade 3 hearing loss. Conclusion: An IMRT tumor-bed boost results in excellent local control while delivering a low mean dose to the cochlea, resulting in a low rate of ototoxicity.

  15. Preconditioning boosts regenerative programmes in the adult zebrafish heart

    PubMed Central

    de Preux Charles, Anne-Sophie; Bise, Thomas; Baier, Felix; Sallin, Pauline; Jaźwińska, Anna

    2016-01-01

    During preconditioning, exposure to a non-lethal harmful stimulus triggers a body-wide increase of survival and pro-regenerative programmes that enable the organism to better withstand the deleterious effects of subsequent injuries. This phenomenon has first been described in the mammalian heart, where it leads to a reduction of infarct size and limits the dysfunction of the injured organ. Despite its important clinical outcome, the actual mechanisms underlying preconditioning-induced cardioprotection remain unclear. Here, we describe two independent models of cardiac preconditioning in the adult zebrafish. As noxious stimuli, we used either a thoracotomy procedure or an induction of sterile inflammation by intraperitoneal injection of immunogenic particles. Similar to mammalian preconditioning, the zebrafish heart displayed increased expression of cardioprotective genes in response to these stimuli. As zebrafish cardiomyocytes have an endogenous proliferative capacity, preconditioning further elevated the re-entry into the cell cycle in the intact heart. This enhanced cycling activity led to a long-term modification of the myocardium architecture. Importantly, the protected phenotype brought beneficial effects for heart regeneration within one week after cryoinjury, such as a more effective cell-cycle reentry, enhanced reactivation of embryonic gene expression at the injury border, and improved cell survival shortly after injury. This study reveals that exposure to antecedent stimuli induces adaptive responses that render the fish more efficient in the activation of the regenerative programmes following heart damage. Our results open a new field of research by providing the adult zebrafish as a model system to study remote cardiac preconditioning. PMID:27440423

  16. Radiotherapy Breast Boost With Reduced Whole-Breast Dose Is Associated With Improved Cosmesis: The Results of a Comprehensive Assessment From the St. George and Wollongong Randomized Breast Boost Trial

    SciTech Connect

    Hau, Eric; Browne, Lois H.; Khanna, Sam; Cail, Stacy; Cert, Grad; Chin, Yaw; Clark, Catherine; Inder, Stephanie; Szwajcer, Alison; Graham, Peter H.

    2012-02-01

    Purpose: To evaluate comprehensively the effect of a radiotherapy boost on breast cosmetic outcomes after 5 years in patients treated with breast-conserving surgery. Methods: The St. George and Wollongong trial (NCT00138814) randomized 688 patients with histologically proven Tis-2, N 0-1, M0 carcinoma to the control arm of 50 Gy in 25 fractions (342 patients) and the boost arm of 45 Gy in 25 fractions to the whole breast followed by a 16 Gy in 8 fraction electron boost (346 patients). Five-year cosmetic outcomes were assessed by a panel subjectively in 385 patients and objectively using pBRA (relative breast retraction assessment). A subset of patients also had absolute BRA measurements. Clinician assessment and patient self-assessment of overall cosmetic and specific items as well as computer BCCT.core analysis were also performed. Results: The boost arm had improved cosmetic overall outcomes as scored by the panel and BCCT.core software with 79% (p = 0.016) and 81% (p = 0.004) excellent/good cosmesis respectively compared with 68% in no-boost arm. The boost arm also had lower pBRA and BRA values with a mean difference of 0.60 and 1.82 mm, respectively, but was not statistically significant. There was a very high proportion of overall excellent/good cosmetic outcome in 95% and 93% in the boost and no-boost arms using patient self-assessment. However, no difference in overall and specific items scored by clinician assessment and patient self-assessment was found. Conclusion: The results show the negative cosmetic effect of a 16-Gy boost is offset by a lower whole-breast dose of 45 Gy.

  17. Impact of Boost Radiation in the Treatment of Ductal Carcinoma In Situ: A Population-Based Analysis

    SciTech Connect

    Rakovitch, Eileen; Narod, Steven A.; Nofech-Moses, Sharon; Hanna, Wedad; Thiruchelvam, Deva; Saskin, Refik; Taylor, Carole; Tuck, Alan; Youngson, Bruce; Miller, Naomi; Done, Susan J.; Sengupta, Sandip; Elavathil, Leela; Jani, Prashant A.; Bonin, Michel; Metcalfe, Stephanie; Paszat, Lawrence

    2013-07-01

    Purpose: To report the outcomes of a population of women with ductal carcinoma in situ (DCIS) treated with breast-conserving surgery and radiation and to evaluate the independent effect of boost radiation on the development of local recurrence. Methods and Materials: All women diagnosed with DCIS and treated with breast-conserving surgery and radiation therapy in Ontario from 1994 to 2003 were identified. Treatments and outcomes were identified through administrative databases and validated by chart review. The impact of boost radiation on the development of local recurrence was determined using survival analyses. Results: We identified 1895 cases of DCIS that were treated by breast-conserving surgery and radiation therapy; 561 patients received boost radiation. The cumulative 10-year rate of local recurrence was 13% for women who received boost radiation and 12% for those who did not (P=.3). The 10-year local recurrence-free survival (LRFS) rate among women who did and who did not receive boost radiation was 88% and 87%, respectively (P=.27), 94% and 93% for invasive LRFS (P=.58), and was 95% and 93% for DCIS LRFS (P=.31). On multivariable analyses, boost radiation was not associated with a lower risk of local recurrence (hazard ratio = 0.82, 95% confidence interval 0.59-1.15) (P=.25). Conclusions: Among a population of women treated with breast-conserving surgery and radiation for DCIS, additional (boost) radiation was not associated with a lower risk of local or invasive recurrence.

  18. Effects of Hyperbolic Rotation in Minkowski Space on the Modeling of Plasma Accelerators in a Lorentz Boosted Frame

    SciTech Connect

    Vay, J.-L.; Geddes, C. G. R.; Cormier-Michel, E.; Grote, D. P.

    2010-09-21

    Laser driven plasma accelerators promise much shorter particle accelerators but their development requires detailed simulations that challenge or exceed current capabilities. We report the first direct simulations of stages up to 1 TeV from simulations using a Lorentz boosted calculation frame resulting in a million times speedup, thanks to a frame boost as high as gamma = 1300. Effects of the hyperbolic rotation in Minkowski space resulting from the frame boost on the laser propagation in the plasma is shown to be key in the mitigation of a numerical instability that was limiting previous attempts.

  19. Facile One-Step Strategy for Highly Boosted Microbial Extracellular Electron Transfer of the Genus Shewanella.

    PubMed

    Wang, Yuan; Lv, Meiling; Meng, Qingan; Ding, Chunmei; Jiang, Lei; Liu, Huan

    2016-06-28

    High performance of bacterial extracellular electron transfer (EET) is essentially important for its practical applications in versatile bioelectric fields. We developed a facile one-step approach to dramatically boost the bacterial EET activity 75-fold by exogenous addition of ethylenediamine tetraacetic acid disodium salt (EDTA-2Na, 1 mM) into the electrochemical cells, where the anodic process of microbial EET was monitored. We propose that EDTA-2Na enables both the alternation of the local environment around the c-type cytochromes located on the outer membrane channels (OMCs), which therefore changes the redox behavior of OMCs in mediating the EET process, and the formation of densely packed biofilm that can further facilitate the EET process. As a synergistic effect, the highly boosted bacterial EET activity was achieved. The method shows good generality for versatile bioelectrical bacteria. We envision that the method is also applicable for constructing various bioelectric devices. PMID:27196945

  20. A High Efficiency Boost Converter with MPPT Scheme for Low Voltage Thermoelectric Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Guan, Mingjie; Wang, Kunpeng; Zhu, Qingyuan; Liao, Wei-Hsin

    2016-11-01

    Using thermoelectric elements to harvest energy from heat has been of great interest during the last decade. This paper presents a direct current-direct current (DC-DC) boost converter with a maximum power point tracking (MPPT) scheme for low input voltage thermoelectric energy harvesting applications. Zero current switch technique is applied in the proposed MPPT scheme. Theoretical analysis on the converter circuits is explored to derive the equations for parameters needed in the design of the boost converter. Simulations and experiments are carried out to verify the theoretical analysis and equations. A prototype of the designed converter is built using discrete components and a low-power microcontroller. The results show that the designed converter can achieve a high efficiency at low input voltage. The experimental efficiency of the designed converter is compared with a commercial converter solution. It is shown that the designed converter has a higher efficiency than the commercial solution in the considered voltage range.

  1. The resveratrol-enriched rice DJ526 boosts motor coordination and physical strength

    PubMed Central

    Chung, Hea-Jong; Sharma, Satya Priya; Kim, Hyeon-Jin; Baek, So-Hyeon; Hong, Seong-Tshool

    2016-01-01

    The main objective of current genetic modifications in crops is to boost agricultural production or to develop GM crops with an improved nutrient profile by introducing a new trait to the plants. A GM crop surpassing the ability of the introduced genetic characteristics has not been developed yet. Here, we show that the resveratrol-enriched rice DJ526, a GM crop, has unexpectedly high beneficial health effects surpassing the introduced genetic characteristic of resveratrol synthetic ability. The synergistic effect of its innate and transgenic properties not only ameliorates age-related deterioration but also boosts motor coordination and physical strength during the aging process. The gene expression profiling analyses by DNA chip showed that the gene expression pattern of mice fed resveratrol-enriched rice DJ526 was very different from mice fed either resveratrol or Dongjin rice alone, respectively, modifying expression of genes related to aging regulation, cell differentiation, extracellular matrix, neurogenesis, or secretion. PMID:27044601

  2. "Virtual" in-vivo bench test for bifurcation stenting with "StentBoost".

    PubMed

    Agostoni, Pierfrancesco; Verheye, Stefan; Vermeersch, Paul; Cornelis, Kristoff; Van Langenhove, Glenn

    2009-04-01

    "StentBoost" is a new angiographic technique that allows improved angiographic visualization of stents deployed in coronary arteries, by enhancing the X-ray focus of the region where the stent is placed. Using this technique we were able to assess the deformation and the expansion of a stent deployed to treat a bifurcation lesion between the mid-left anterior descending (LAD) artery and a big second diagonal branch, during sequential inflations of: (1) the stent per se in the LAD, (2) the ostium of the diagonal branch through the stent struts, (3) the stent again with a non compliant balloon, and (4) both branches with the kissing balloon technique. "StentBoost" guided our clinical and angiographic decision-making process and allowed us to create a "virtual" bench test of the stent deployed at the level of the bifurcation treated.

  3. The resveratrol-enriched rice DJ526 boosts motor coordination and physical strength.

    PubMed

    Chung, Hea-Jong; Sharma, Satya Priya; Kim, Hyeon-Jin; Baek, So-Hyeon; Hong, Seong-Tshool

    2016-01-01

    The main objective of current genetic modifications in crops is to boost agricultural production or to develop GM crops with an improved nutrient profile by introducing a new trait to the plants. A GM crop surpassing the ability of the introduced genetic characteristics has not been developed yet. Here, we show that the resveratrol-enriched rice DJ526, a GM crop, has unexpectedly high beneficial health effects surpassing the introduced genetic characteristic of resveratrol synthetic ability. The synergistic effect of its innate and transgenic properties not only ameliorates age-related deterioration but also boosts motor coordination and physical strength during the aging process. The gene expression profiling analyses by DNA chip showed that the gene expression pattern of mice fed resveratrol-enriched rice DJ526 was very different from mice fed either resveratrol or Dongjin rice alone, respectively, modifying expression of genes related to aging regulation, cell differentiation, extracellular matrix, neurogenesis, or secretion. PMID:27044601

  4. Fractional order Buck-Boost converter in CCM: modelling, analysis and simulations

    NASA Astrophysics Data System (ADS)

    Wang, Faqiang; Ma, Xikui

    2014-12-01

    In this paper, the modelling, analysis and the power electronics simulator (PSIM) simulations of the fractional order Buck-Boost converter operating in continuous conduction mode (CCM) operation are investigated. Based on the three-terminal switch device method, the average circuit model of the fractional order Buck-Boost converter is established, and the corresponding DC equivalent circuit model and AC small signal equivalent circuit model are presented. And then, the equilibrium point and the transfer functions are derived. It is found that the equilibrium point is not influenced by the inductor's or the capacitor's order, but both these orders are included in the derived transfer functions. Finally, the comparisons between the theoretical analysis and the PSIM simulations are given for confirmation.

  5. Jet shapes for boosted jet two-prong decays from first-principles

    NASA Astrophysics Data System (ADS)

    Dasgupta, Mrinal; Schunk, Laís; Soyez, Gregory

    2016-04-01

    Several boosted jet techniques use jet shape variables to discriminate the multi-pronged signal from Quantum Chromodynamics backgrounds. In this paper, we provide a first-principles study of an important class of jet shapes all of which put a constraint on the subjet mass: the mass-drop parameter ( μ 2), the N -subjettiness ratio ( τ 21 ( β = 2) ) and energy correlation functions ( C 2 ( β = 2) or D 2 ( β = 2) . We provide analytic results both for QCD background jets as well as for signal processes. We further study the situation where cuts on these variables are applied recursively with Cambridge-Aachen de-clustering of the original jet. We also explore the effect of the choice of axis for N -subjettiness and jet de-clustering. Our results bring substantial new insight into the nature, gain and relative performance of each of these methods, which we expect will influence their future application for boosted object searches.

  6. Design and real time implementation of single phase boost power factor correction converter.

    PubMed

    Bouafassa, Amar; Rahmani, Lazhar; Mekhilef, Saad

    2015-03-01

    This paper presents a real time implementation of the single-phase power factor correction (PFC) AC-DC boost converter. A combination of higher order sliding mode controller based on super twisting algorithm and predictive control techniques are implemented to improve the performance of the boost converter. Due to the chattering effects, the higher order sliding mode control (HOSMC) is designed. Also, the predictive technique is modified taking into account the large computational delays. The robustness of the controller is verified conducting simulation in MATLAB, the results show good performances in both steady and transient states. An experiment is conducted through a test bench based on dSPACE 1104. The experimental results proved that the proposed controller enhanced the performance of the converter under different parameters variations.

  7. Zotarolimus-eluting stent fracture at initial implantation diagnosed with StentBoost

    PubMed Central

    Arat Ozkan, Alev; Sinan, Umit Yasar; Gurmen, Aziz T

    2016-01-01

    Stent fracture is a rare complication of drug-eluting stent implantation with a reported rate of 0.84%–3.2% in various clinical studies with first-generation drug-eluting stents and 29% in autopsy studies. Sirolimus-eluting stents with their closed cell design were reported to be more prone to fracture compared to paclitaxel-eluting stents. Other risk factors for stent fracture are multiple stenting, longer stent length, chronic renal failure, right coronary artery intervention, and a higher maximal inflation pressure. The role of angiography in diagnosing stent fracture is limited, a fact also questioning the reliability of angiographic data. Image enhancement techniques like StentBoost are widely available in new-generation angiography systems and are used to assess stent expansion, overlap size, or to localize the postdilation balloon. Here, we report a case of zotarolimus-eluting stent fracture at initial implantation diagnosed with StentBoost. PMID:27489714

  8. A High Efficiency Boost Converter with MPPT Scheme for Low Voltage Thermoelectric Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Guan, Mingjie; Wang, Kunpeng; Zhu, Qingyuan; Liao, Wei-Hsin

    2016-07-01

    Using thermoelectric elements to harvest energy from heat has been of great interest during the last decade. This paper presents a direct current-direct current (DC-DC) boost converter with a maximum power point tracking (MPPT) scheme for low input voltage thermoelectric energy harvesting applications. Zero current switch technique is applied in the proposed MPPT scheme. Theoretical analysis on the converter circuits is explored to derive the equations for parameters needed in the design of the boost converter. Simulations and experiments are carried out to verify the theoretical analysis and equations. A prototype of the designed converter is built using discrete components and a low-power microcontroller. The results show that the designed converter can achieve a high efficiency at low input voltage. The experimental efficiency of the designed converter is compared with a commercial converter solution. It is shown that the designed converter has a higher efficiency than the commercial solution in the considered voltage range.

  9. Design of a high efficiency 30 kW boost composite converter

    SciTech Connect

    Kim, Hyeokjin; Chen, Hua; Maksimovic, Dragan; Erickson, Robert W.

    2015-09-20

    An experimental 30 kW boost composite converter is described in this paper. The composite converter architecture, which consists of a buck module, a boost module, and a dual active bridge module that operates as a DC transformer (DCX), leads to substantial reductions in losses at partial power points, and to significant improvements in weighted efficiency in applications that require wide variations in power and conversion ratio. A comprehensive loss model is developed, accounting for semiconductor conduction and switching losses, capacitor losses, as well as dc and ac losses in magnetic components. Based on the developed loss model, the module and system designs are optimized to maximize efficiency at a 50% power point. Experimental results for the 30 kW prototype demonstrate 98.5%peak efficiency, very high efficiency over wide ranges of power and voltage conversion ratios, as well as excellent agreements between model predictions and measured efficiency curves.

  10. Design and real time implementation of single phase boost power factor correction converter.

    PubMed

    Bouafassa, Amar; Rahmani, Lazhar; Mekhilef, Saad

    2015-03-01

    This paper presents a real time implementation of the single-phase power factor correction (PFC) AC-DC boost converter. A combination of higher order sliding mode controller based on super twisting algorithm and predictive control techniques are implemented to improve the performance of the boost converter. Due to the chattering effects, the higher order sliding mode control (HOSMC) is designed. Also, the predictive technique is modified taking into account the large computational delays. The robustness of the controller is verified conducting simulation in MATLAB, the results show good performances in both steady and transient states. An experiment is conducted through a test bench based on dSPACE 1104. The experimental results proved that the proposed controller enhanced the performance of the converter under different parameters variations. PMID:25457043

  11. Mitochondrial oligomers boost glycolysis in cancer stem cells to facilitate blebbishield-mediated transformation after apoptosis.

    PubMed

    Jinesh, G G; Molina, J R; Huang, L; Laing, N M; Mills, G B; Bar-Eli, M; Kamat, A M

    2016-01-01

    Apoptosis culminates in secondary necrosis due to lack of ATP. Cancer stem cells form spheres after apoptosis by evoking the blebbishield emergency program. Hence, determining how blebbishields avoid secondary necrosis is crucial. Here we demonstrate that N-Myc and VEGFR2 control transformation from blebbishields, during which oligomers of K-Ras, p27, BAD, Bax, and Bak boost glycolysis to avoid secondary necrosis. Non-apoptotic cancer cells also utilize oligomers to boost glycolysis, which differentiates the glycolytic function of oligomers from their apoptotic action. Smac mimetic in combination with TNF-α or TRAIL but not in combination with FasL abrogates transformation from blebbishields by inducing secondary necrosis. Thus blebbishield-mediated transformation is dependent on glycolysis, and Smac mimetics represent potential candidates to abrogate the blebbishield emergency program. PMID:27551498

  12. Boost of plasma current with active magnetic field shaping coils in rotamak discharges

    SciTech Connect

    Yang Xiaokang; Goss, Jermain; Kalaria, Dhara; Huang, Tian Sen

    2011-08-15

    A set of magnetic shaping coils is installed on the Prairie View (PV) rotamak for the study of active plasma shape control in the regimes with and without toroidal field (TF). In the spherical tokamak regime (with TF), plasma current I{sub p} can be boosted by 200% when all five shaping coils (connected in series) are energized. The enhancement of current drive efficiency is mainly attributed to the radial compression and the substantially axial extension of the plasma column; this in turn improves the impedance matching and thus increases antenna input power. In the field-reversed configuration (without TF), plasma current can be boosted by 100% when one middle coil is used; the appearance of radial shift mode limits the achievable value of I{sub p}. The experiments clearly demonstrate that the plasma shape control plays a role in effectively driving plasma current in rotamaks.

  13. Zotarolimus-eluting stent fracture at initial implantation diagnosed with StentBoost.

    PubMed

    Arat Ozkan, Alev; Sinan, Umit Yasar; Gurmen, Aziz T

    2016-01-01

    Stent fracture is a rare complication of drug-eluting stent implantation with a reported rate of 0.84%-3.2% in various clinical studies with first-generation drug-eluting stents and 29% in autopsy studies. Sirolimus-eluting stents with their closed cell design were reported to be more prone to fracture compared to paclitaxel-eluting stents. Other risk factors for stent fracture are multiple stenting, longer stent length, chronic renal failure, right coronary artery intervention, and a higher maximal inflation pressure. The role of angiography in diagnosing stent fracture is limited, a fact also questioning the reliability of angiographic data. Image enhancement techniques like StentBoost are widely available in new-generation angiography systems and are used to assess stent expansion, overlap size, or to localize the postdilation balloon. Here, we report a case of zotarolimus-eluting stent fracture at initial implantation diagnosed with StentBoost. PMID:27489714

  14. Boosting capacitive blue-energy and desalination devices with waste heat.

    PubMed

    Janssen, Mathijs; Härtel, Andreas; van Roij, René

    2014-12-31

    We show that sustainably harvesting "blue" energy from the spontaneous mixing process of fresh and salty water can be boosted by varying the water temperature during a capacitive mixing process. Our modified Poisson-Boltzmann calculations predict a strong temperature dependence of the electrostatic potential of a charged electrode in contact with an adjacent aqueous 1:1 electrolyte. We propose to exploit this dependence to boost the efficiency of capacitive blue engines, which are based on cyclically charging and discharging nanoporous supercapacitors immersed in salty and fresh water, respectively [D. Brogioli, Phys. Rev. Lett. 103, 058501 (2009)]. We show that the energy output of blue engines can be increased by a factor of order 2 if warm (waste-heated) fresh water is mixed with cold sea water. Moreover, the underlying physics can also be used to optimize the reverse process of capacitive desalination of water.

  15. Organizational Adaptation and Higher Education.

    ERIC Educational Resources Information Center

    Cameron, Kim S.

    1984-01-01

    Organizational adaptation and types of adaptation needed in academe in the future are reviewed and major conceptual approaches to organizational adaptation are presented. The probable environment that institutions will face in the future that will require adaptation is discussed. (MLW)

  16. Human heat adaptation.

    PubMed

    Taylor, Nigel A S

    2014-01-01

    In this overview, human morphological and functional adaptations during naturally and artificially induced heat adaptation are explored. Through discussions of adaptation theory and practice, a theoretical basis is constructed for evaluating heat adaptation. It will be argued that some adaptations are specific to the treatment used, while others are generalized. Regarding ethnic differences in heat tolerance, the case is put that reported differences in heat tolerance are not due to natural selection, but can be explained on the basis of variations in adaptation opportunity. These concepts are expanded to illustrate how traditional heat adaptation and acclimatization represent forms of habituation, and thermal clamping (controlled hyperthermia) is proposed as a superior model for mechanistic research. Indeed, this technique has led to questioning the perceived wisdom of body-fluid changes, such as the expansion and subsequent decay of plasma volume, and sudomotor function, including sweat habituation and redistribution. Throughout, this contribution was aimed at taking another step toward understanding the phenomenon of heat adaptation and stimulating future research. In this regard, research questions are posed concerning the influence that variations in morphological configuration may exert upon adaptation, the determinants of postexercise plasma volume recovery, and the physiological mechanisms that modify the cholinergic sensitivity of sweat glands, and changes in basal metabolic rate and body core temperature following adaptation.

  17. How to Boost Positive Interpretations? A Meta-Analysis of the Effectiveness of Cognitive Bias Modification for Interpretation

    PubMed Central

    Menne-Lothmann, Claudia; Viechtbauer, Wolfgang; Höhn, Petra; Kasanova, Zuzana; Haller, Simone P.; Drukker, Marjan; van Os, Jim; Wichers, Marieke; Lau, Jennifer Y. F.

    2014-01-01

    The current meta-analysis explores the strength of effects of cognitive bias modification training for interpretation bias (CBM-I) on positive (i.e., adaptive) interpretations and mood as well as the training and sample characteristics influencing these effects. Data-bases were searched with the key words “interpret* bias AND training” and “interpret* bias AND modif*”. Reference lists of identified articles were checked and authors of identified articles were contacted for further relevant articles and unpublished data. Studies were reviewed for inclusion with eligibility criteria being that the study (a) aimed to target interpretation biases through any kind of training, (b) assessed mood and/or interpretation bias as outcome measures, (c) allocated individuals to training conditions at random, and (d) recruited adult samples. A meta-analytic multilevel mixed-effects model was employed to assess standardized mean changes in interpretation bias, negative mood, and emotional reactivity. In addition, several training and sample characteristics were explored for their potential to enhance benign training effectiveness. On average, benign CBM-I resulted in an increase in positive interpretation bias (p<.01) and a decrease in negative mood state (p<.001), but did not affect emotional reactivity. These effects were not consistently different from control conditions with no or neutral training. However, within benign training conditions imagery instructions and more training sessions were related to larger cognitive and mood effects, whereas feedback about training performance and inclusion of non-benign training items (instead of including benign items only) boosted cognitive effects only. Finally, training was more effective in women (cognitive and mood effects) and presumably samples with symptomatic emotional dysregulation (cognitive effects). Although the effects of emotional dysregulation and number of training sessions could not well be distinguished, there

  18. Hyperinsulinemia may boost both hematocrit and iron absorption by up-regulating activity of hypoxia-inducible factor-1alpha.

    PubMed

    McCarty, M F

    2003-01-01

    There is growing evidence that increases in both hematocrit and body iron stores are components of the insulin resistance syndrome. The ability of insulin and of IGF-I - whose effective activity is increased in the context of insulin resistance - to boost activity of the transcription factor hypoxia-inducible factor-1alpha (HIF-1alpha), may be at least partially responsible for this association. HIF-1alpha, which functions physiologically as a detector of both hypoxia and iron-deficiency, promotes synthesis of erythropoietin, and may also mediate the up-regulatory impact of hypoxia on intestinal iron absorption. Insulin/IGF-I may also influence erythropoiesis more directly, as they are growth factors for developing reticulocytes. Conversely, the activation of HIF-1alpha associated with iron deficiency may be responsible for the increased glucose tolerance noted in iron-deficient animals; HIF-1alpha promotes efficient glucose uptake and glycolysis - a sensible adaptation to hypoxia - by inducing increased synthesis of glucose transporters and glycolytic enzymes. Recent reports that phlebotomy can increase the efficiency of muscle glucose uptake in lean healthy omnivores are intriguing and require further confirmation. Whether increased iron stores contribute to the elevated vascular risk associated with insulin resistance is doubtful, inasmuch as most prospective studies fail to correlate serum ferritin or transferrin saturation with subsequent vascular events. However, current data are reasonably consistent with the possibility that moderately elevated iron stores are associated with increased overall risk for cancer - and for colorectal cancer in particular; free iron may play a catalytic role in 'spontaneous' mutagenesis. Thus, iron excess may mediate at least some of the increased cancer risk associated with insulin resistance and heme-rich diets. People who are insulin resistant can minimize any health risk associated with iron overload by avoiding heme

  19. Population pharmacokinetics of ritonavir-boosted atazanavir in HIV-infected patients and healthy volunteers

    PubMed Central

    Dickinson, Laura; Boffito, Marta; Back, David; Waters, Laura; Else, Laura; Davies, Geraint; Khoo, Saye; Pozniak, Anton; Aarons, Leon

    2009-01-01

    Objectives The aim of this study was to develop and validate a population pharmacokinetic model to: (i) describe ritonavir-boosted atazanavir concentrations (300/100 mg once daily) and identify important covariates; and (ii) evaluate the predictive performance of the model for lower, unlicensed atazanavir doses (150 and 200 mg once daily) boosted with ritonavir (100 mg once daily). Methods Non-linear mixed effects modelling was applied to determine atazanavir pharmacokinetic parameters, inter-individual variability (IIV) and residual error. Covariates potentially related to atazanavir pharmacokinetics were explored. The final model was assessed by means of a visual predictive check for 300/100, 200/100 and 150/100 mg once daily. Results Forty-six individuals were included (30 HIV-infected). A one-compartment model with first-order absorption and lag-time best described the data. Final estimates of apparent oral clearance (CL/F), volume of distribution (V/F) and absorption rate constant [relative standard error (%) and IIV (%)] were 7.7 L/h (5, 29), 103 L (13, 48) and 3.4 h−1 (34, 154); a lag-time of 0.96 h (1) was determined. Ritonavir area under the curve (AUC0–24) was the only significant covariate. Overall, 94%–97% of observed concentrations were within the 95% prediction intervals for all three regimens. Conclusions A population pharmacokinetic model for ritonavir-boosted atazanavir has been developed and validated. Ritonavir AUC0–24 was significantly associated with atazanavir CL/F. The model was used to investigate other, particularly lower, ritonavir-boosted atazanavir dosing strategies. PMID:19329800

  20. Rest boosts the long-term retention of spatial associative and temporal order information.

    PubMed

    Craig, Michael; Dewar, Michaela; Della Sala, Sergio; Wolbers, Thomas

    2015-09-01

    People retain more new verbal episodic information for at least 7 days if they rest for a few minutes after learning than if they attend to new information. It is hypothesized that rest allows for superior consolidation of new memories. In rodents, rest periods promote hippocampal replay of a recently travelled route, and this replay is thought to be critical for memory consolidation and subsequent spatial navigation. If rest boosts human memory by promoting hippocampal replay/consolidation, then the beneficial effect of rest should extend to complex (hippocampal) memory tasks, for example, tasks probing associations and sequences. We investigated this question via a virtual reality route memory task. Healthy young participants learned two routes to a 100% criterion. One route was followed by a 10-min rest and the other by a 10-min spot the difference game. For each learned route, participants performed four delayed spatial memory tests probing: (i) associative (landmark-direction) memory, (ii) cognitive map formation, (iii) temporal (landmark) order memory, and (iv) route memory. Tests were repeated after 7 days to determine any long-term effects. No effect of rest was detected in the route memory or cognitive map tests, most likely due to ceiling and floor effects, respectively. Rest did, however, boost retention in the associative memory and temporal order memory tests, and this boost remained for at least 7 days. We therefore demonstrate that the benefit of rest extends to (spatial) associative and temporal order memory in humans. We hypothesise that rest allows superior consolidation/hippocampal replay of novel information pertaining to a recently learned route, thus boosting new memories over the long term. PMID:25620400

  1. Characteristic form of boost-invariant and cylindrically asymmetric hydrodynamic equations

    SciTech Connect

    Chojnacki, Mikolaj; Florkowski, Wojciech

    2006-09-15

    It is shown that the boost-invariant and cylindrically asymmetric hydrodynamic equations for baryon-free matter may be reduced to only two coupled partial differential equations. In the case where the system exhibits the crossover phase transition, the standard numerical methods may be applied to solve these equations and the proposed scheme allows for a very convenient analysis of the cylindrically asymmetric hydrodynamic expansion.

  2. Phase II Study of Preoperative Helical Tomotherapy With a Simultaneous Integrated Boost for Rectal Cancer

    SciTech Connect

    Engels, Benedikt; Tournel, Koen; Everaert, Hendrik; Hoorens, Anne; Sermeus, Alexandra; Christian, Nicolas; Storme, Guy; Verellen, Dirk; De Ridder, Mark

    2012-05-01

    Purpose: The addition of concomitant chemotherapy to preoperative radiotherapy is considered the standard of care for patients with cT3-4 rectal cancer. The combined treatment modality increases the complete response rate and local control (LC), but has no impact on survival or the incidence of distant metastases. In addition, it is associated with considerable toxicity. As an alternative strategy, we explored prospectively, preoperative helical tomotherapy with a simultaneous integrated boost (SIB). Methods and Materials: A total of 108 patients were treated with intensity-modulated and image-guided radiotherapy using the Tomotherapy Hi-Art II system. A dose of 46 Gy, in daily fractions of 2 Gy, was delivered to the mesorectum and draining lymph nodes, without concomitant chemotherapy. Patients with an anticipated circumferential resection margin (CRM) of less than 2 mm, based on magnetic resonance imaging, received a SIB to the tumor up to a total dose of 55.2 Gy. Acute and late side effects were scored using the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. Results: A total of 102 patients presented with cT3-4 tumors; 57 patients entered the boost group and 51 the no-boost group. One patient in the no-boost group developed a radio-hypersensitivity reaction, resulting in a complete tumor remission, a Grade 3 acute and Grade 5 late enteritis. No other Grade {>=}3 acute toxicities occurred. With a median follow-up of 32 months, Grade {>=}3 late gastrointestinal and urinary toxicity were observed in 6% and 4% of the patients, respectively. The actuarial 2-year LC, progression-free survival and overall survival were 98%, 79%, and 93%. Conclusions: Preoperative helical tomotherapy displays a favorable acute toxicity profile in patients with cT3-4 rectal cancer. A SIB can be safely administered in patients with a narrow CRM and resulted in a promising LC.

  3. Advanced Condenser Boosts Geothermal Power Plant Output (Fact Sheet), The Spectrum of Clean Energy Innovation

    SciTech Connect

    Not Available

    2010-12-01

    When power production at The Geysers geothermal power complex began to falter, the National Renewable Energy Laboratory (NREL) stepped in, developing advanced condensing technology that dramatically boosted production efficiency - and making a major contribution to the effective use of geothermal power. NREL developed advanced direct-contact condenser (ADCC) technology to condense spent steam more effectively, improving power production efficiency in Unit 11 by 5%.

  4. Linearized stability analysis and design of a flyback dc-dc boost regulator.

    NASA Technical Reports Server (NTRS)

    Wester, G. W.

    1973-01-01

    Analytic expressions for the small-signal power-stage describing functions of a switched dc-dc boost regulator are derived from an approximate continuous circuit model which is developed by a time-averaging technique. Closed-loop stability is attained through the design of frequency compensation of the loop gain. Open- and closed-loop regulator output impedances are derived from the linearized models for the given configuration. The analysis and design are compared with and confirmed by breadboard measurements.

  5. Historical and Current U.S. Strategies for Boosting Distributed Generation (Chinese Translation)

    SciTech Connect

    Lowder, Travis; Schwabe, Paul; Zhou, Ella; Arent, Douglas J.

    2015-08-01

    This is the Chinese translation of NREL/TP-6A20-64843. This report seeks to introduce a variety of top-down and bottom-up practices that, in concert with the macro-environment of cost-reduction globally and early adoption in Europe, helped boost the distributed generation photovoltaic market in the United States. These experiences may serve as a reference in China's quest to promote distributed renewable energy.

  6. Excellent Local Control With Stereotactic Radiotherapy Boost After External Beam Radiotherapy in Patients With Nasopharyngeal Carcinoma

    SciTech Connect

    Hara, Wendy; Loo, Billy W.; Goffinet, Don R.; Chang, Steven D.; Adler, John R.; Pinto, Harlan A.; Fee, Willard E.; Kaplan, Michael J.; Fischbein, Nancy J.; Le, Quynh-Thu

    2008-06-01

    Purpose: To determine long-term outcomes in patients receiving stereotactic radiotherapy (SRT) as a boost after external beam radiotherapy (EBRT) for locally advanced nasopharyngeal carcinoma (NPC). Methods and Materials: Eight-two patients received an SRT boost after EBRT between September 1992 and July 2006. Nine patients had T1, 30 had T2, 12 had T3, and 31 had T4 tumors. Sixteen patients had Stage II, 19 had Stage III, and 47 had Stage IV disease. Patients received 66 Gy of EBRT followed by a single-fraction SRT boost of 7-15 Gy, delivered 2-6 weeks after EBRT. Seventy patients also received cisplatin-based chemotherapy delivered concurrently with and adjuvant to radiotherapy. Results: At a median follow-up of 40.7 months (range, 6.5-144.2 months) for living patients, there was only 1 local failure in a patient with a T4 tumor. At 5 years, the freedom from local relapse rate was 98%, freedom from nodal relapse 83%, freedom from distant metastasis 68%, freedom from any relapse 67%, and overall survival 69%. Late toxicity included radiation-related retinopathy in 3, carotid aneurysm in 1, and radiographic temporal lobe necrosis in 10 patients, of whom 2 patients were symptomatic with seizures. Of 10 patients with temporal lobe necrosis, 9 had T4 tumors. Conclusion: Stereotactic radiotherapy boost after EBRT provides excellent local control for patients with NPC. Improved target delineation and dose homogeneity of radiation delivery for both EBRT and SRT is important to avoid long-term complications. Better systemic therapies for distant control are needed.

  7. Hypofractionation with no boost after breast conservation in early-stage breast cancer patients.

    PubMed

    Arcadipane, Francesca; Franco, Pierfrancesco; De Colle, Chiara; Rondi, Nadia; Di Muzio, Jacopo; Pelle, Emanuela; Martini, Stefania; Ala, Ada; Airoldi, Mario; Donadio, Michela; De Sanctis, Corrado; Castellano, Isabella; Ragona, Riccardo; Ricardi, Umberto

    2016-10-01

    The aim of this study was to evaluate local control, survival and toxicity profile of a consecutive cohort of early-stage breast cancer (EBC) patients treated with adjuvant hypofractionated radiotherapy (HF) with no boost delivered to the lumpectomy cavity, after breast-conserving surgery (BCS). Between 2005 and 2015, a total of 493 women affected with EBC were treated with HF (46 Gy/20 fractions or 40.05 Gy/15 fractions) to the whole breast without boost to tumor bed, because of age and/or favorable tumor characteristics. The primary endpoint was 5-year actuarial local control (LC); secondary endpoints included survival, toxicity profile and cosmesis. Median follow-up was 57 months (range 6-124). Actuarial 5-year overall, cancer-specific, disease-free survival and LC were 96.3, 98.9, 97.8 and 98.6 %, respectively. On multivariate analysis, tumor stage (T1 vs. T2) and hormonal status (positive vs. negative estrogen receptors) were significantly correlated with LC. Only 2 % of patients experienced ≥G3 acute skin toxicity. Late toxicity was mild with only 1 case of G3 fibrosis. Most of the patients (95 %) had good-excellent cosmetic results. HF to the whole breast with no boost delivered to the tumor bed is a safe and effective option for a population of low-risk breast cancer patients after BCS, with excellent 5-year LC, mild toxicity profile and promising cosmetic outcome. A subgroup of patients with larger tumors and/or with no estrogen receptor expression may potentially benefit from treatment intensification with a boost dose to the lumpectomy cavity. PMID:27573380

  8. Adjuvant stereotactic permanent seed breast implant: A boost series in view of partial breast irradiation

    SciTech Connect

    Jansen, Nicolas . E-mail: nicolas.jansen@chu.ulg.ac.be; Deneufbourg, Jean-Marie; Nickers, Philippe

    2007-03-15

    Purpose: The aim of this study was to use permanent seed implants in the breast and describe our experience with 15 cases, using iodine seed implants as a tumor bed boost. Methods and Materials: Breasts were fixed with a thermoplastic sheet, a template bridge applied, the thorax scanned and the images rotated to be perpendicular to the implant axis. Skin, heart, and lung were delineated. A preplan was made, prescribing 50 Gy to the clinical target volume (CTV), consisting in this boost series of nearly a quadrant. Iodine (125) seeds were stereotactically implanted through the template, and results were checked with a postplan computed tomographic (CT) scan. Results: The breast was immobilized reproducibly. Simulation, scanning, and implant were performed without difficulties. Preplan CTV D90% (the dose delivered to 90% of the CTV) was 66 Gy, and postoperative fluoroscopic or CT scan checks were satisfactory. Pre- and postplan dose-volume histogram showed good organ sparing: mean postplan skin, heart, and lung V30 Gy (the organ volume receiving a dose of 30 Gy) of 2 {+-} 2.2 mL, 0.24 {+-} 0.34 mL, and 3.5 {+-} 5 mL, respectively. No short-term toxicity above Grade 1 was noted, except for transient Grade 3 neuropathy in 1 patient. Conclusions: Seeds remained in the right place, as assessed by fluoroscopy, absence of significant pre- to postplan dose-volume histogram change for critical organs, and total irradiated breast volume. The method could be proposed as a boost when high dosimetric selectivity is required (young patients after cardiotoxic chemotherapy for left-sided cancer). This boost series was a preliminary step before testing partial breast irradiation by permanent seed implant in a prospective trial.

  9. Boosting theoretical zeolitic framework generation for the determination of new materials structures using GPU programming.

    PubMed

    Baumes, Laurent A; Kruger, Frederic; Jimenez, Santiago; Collet, Pierre; Corma, Avelino

    2011-03-14

    Evolutionary algorithms have proved to be efficient for solving complicated optimization problems. On the other hand, the many-core architecture in graphical cards "General Purpose Graphic Processing Unit" (GPGPU) offers one of the most attractive cost/performance ratio. Using such hardware, the manuscript shows how an efficiently implemented genetic algorithm with a simple fitness function allows boosting the determination of zeolite structures. A case study is presented. PMID:21283845

  10. Understanding the Mechanisms Through Which an Influential Early Childhood Program Boosted Adult Outcomes

    PubMed Central

    Heckman, James; Pinto, Rodrigo

    2013-01-01

    A growing literature establishes that high quality early childhood interventions targeted toward disadvantaged children have substantial impacts on later life outcomes. Little is known about the mechanisms producing these impacts. This paper uses longitudinal data on cognitive and personality traits from an experimental evaluation of the influential Perry Preschool program to analyze the channels through which the program boosted both male and female participant outcomes. Experimentally induced changes in personality traits explain a sizable portion of adult treatment effects. PMID:24634518

  11. High-Dose-Rate Brachytherapy Boost for Prostate Cancer: Comparison of Two Different Fractionation Schemes

    SciTech Connect

    Kaprealian, Tania; Weinberg, Vivian; Speight, Joycelyn L.; Gottschalk, Alexander R.; Roach, Mack; Shinohara, Katsuto; Hsu, I.-Chow

    2012-01-01

    Purpose: This is a retrospective study comparing our experience with high-dose-rate (HDR) brachytherapy boost for prostate cancer, using two different fractionation schemes, 600 cGy Multiplication-Sign 3 fractions (patient group 1) and 950 cGy Multiplication-Sign 2 fractions (patient group 2). Methods and Materials: A total of 165 patients were treated for prostate cancer using external beam radiation therapy up to a dose of 45 Gy, followed by an HDR brachytherapy prostate radiation boost. Between July 1997 and Nov 1999, 64 patients were treated with an HDR boost of 600 cGy Multiplication-Sign 3 fractions; and between June 2000 and Nov 2005, 101 patients were treated with an HDR boost of 950 cGy Multiplication-Sign 2 fractions. All but 9 patients had at least one of the following risk features: pretreatment prostate-specific antigen (PSA) level >10, a Gleason score {>=}7, and/or clinical stage T3 disease. Results: Median follow-up was 105 months for group 1 and 43 months for group 2. Patients in group 2 had a greater number of high-risk features than group 1 (p = 0.02). Adjusted for comparable follow-up, there was no difference in biochemical no-evidence-of-disease (bNED) rate between the two fractionation scheme approaches, with 5-year Kaplan-Meier estimates of 93.5% in group 1 and 87.3% in group 2 (p = 0.19). The 5-year estimates of progression-free survival were 86% for group 1 and 83% for group 2 (p = 0.53). Among high-risk patients, there were no differences in bNED or PFS rate due to fractionation. Conclusions: Results were excellent for both groups. Adjusted for comparable follow-up, no differences were found between groups.

  12. How attentional boost interacts with reward: the effect of dopaminergic medications in Parkinson's disease.

    PubMed

    Kéri, Szabolcs; Nagy, Helga; Levy-Gigi, Einat; Kelemen, Oguz

    2013-12-01

    There is widespread evidence that dopamine is implicated in the regulation of reward and salience. However, it is less known how these processes interact with attention and recognition memory. To explore this question, we used the attentional boost test in patients with Parkinson's disease (PD) before and after the administration of dopaminergic medications. Participants performed a visual letter detection task (remembering rewarded target letters and ignoring distractor letters) while also viewing a series of photos of natural and urban scenes in the background of the letters. The aim of the game was to retrieve the target letter after each trial and to win as much virtual money as possible. The recognition of background scenes was not rewarded. We enrolled 26 drug-naïve, newly diagnosed patients with PD and 25 healthy controls who were evaluated at baseline and follow-up. Patients with PD received dopamine agonists (pramipexole, ropinirole, rotigotine) during the 12-week follow-up period. At baseline, we found intact attentional boost in patients with PD: they were able to recognize target-associated scenes similarly to controls. At follow-up, patients with PD outperformed controls for both target- and distractor-associated scenes, but not when scenes were presented without letters. The alerting, orienting and executive components of attention were intact in PD. Enhanced attentional boost was replicated in a smaller group of patients with PD (n = 15) receiving l-3,4-dihydroxyphenylalanine (L-DOPA). These results suggest that dopaminergic medications facilitate attentional boost for background information regardless of whether the central task (letter detection) is rewarded or not. PMID:24011183

  13. An adaptive algorithm for low contrast infrared image enhancement

    NASA Astrophysics Data System (ADS)

    Liu, Sheng-dong; Peng, Cheng-yuan; Wang, Ming-jia; Wu, Zhi-guo; Liu, Jia-qi

    2013-08-01

    An adaptive infrared image enhancement algorithm for low contrast is proposed in this paper, to deal with the problem that conventional image enhancement algorithm is not able to effective identify the interesting region when dynamic range is large in image. This algorithm begin with the human visual perception characteristics, take account of the global adaptive image enhancement and local feature boost, not only the contrast of image is raised, but also the texture of picture is more distinct. Firstly, the global image dynamic range is adjusted from the overall, the dynamic range of original image and display grayscale form corresponding relationship, the gray scale of bright object is raised and the the gray scale of dark target is reduced at the same time, to improve the overall image contrast. Secondly, the corresponding filtering algorithm is used on the current point and its neighborhood pixels to extract image texture information, to adjust the brightness of the current point in order to enhance the local contrast of the image. The algorithm overcomes the default that the outline is easy to vague in traditional edge detection algorithm, and ensure the distinctness of texture detail in image enhancement. Lastly, we normalize the global luminance adjustment image and the local brightness adjustment image, to ensure a smooth transition of image details. A lot of experiments is made to compare the algorithm proposed in this paper with other convention image enhancement algorithm, and two groups of vague IR image are taken in experiment. Experiments show that: the contrast ratio of the picture is boosted after handled by histogram equalization algorithm, but the detail of the picture is not clear, the detail of the picture can be distinguished after handled by the Retinex algorithm. The image after deal with by self-adaptive enhancement algorithm proposed in this paper becomes clear in details, and the image contrast is markedly improved in compared with Retinex

  14. "Boosting" in Paralympic athletes with spinal cord injury: doping without drugs.

    PubMed

    Mazzeo, Filomena; Santamaria, Stefania; Iavarone, Alessandro

    2015-01-01

    The intentional activation of autonomic dysreflexia (AD, also called "boosting"), a practice sometimes used by athletes affected by spinal cord injury (SCI), is banned by the International Paralympic Committee (IPC). Although various studies have addressed doping and AD as separate issues, studies evaluating AD as a doping method are lacking. The aim of this brief review is to contribute to better understanding of the relationship between doping and AD. We conducted a literature search of the PubMed database (from 1994 onwards). The key search terms "autonomic dysreflexia" and "boosting" were crossreferenced with "sport performance". The official Paralympic website was also viewed. AD is a potent sympathetic reflex, due to a massive release of noradrenaline, that results in marked vasoconstriction distal to the level of the lesion. Athletes with SCI often self-inflict physical suffering in order to induce this phenomenon, which carries high health risks (i.e., hypertension, cerebral hemorrhage, stroke and sudden death). Boosting is a practice that can be compared to doping methods and the IPC expressly prohibits it. Any deliberate attempt to induce AD, if detected, will lead to disqualification from the sporting event and subsequent investigation by the IPC Legal and Ethics Committee. PMID:26415788

  15. Protecting High Energy Barriers: A New Equation to Regulate Boost Energy in Accelerated Molecular Dynamics Simulations

    PubMed Central

    2011-01-01

    Molecular dynamics (MD) is one of the most common tools in computational chemistry. Recently, our group has employed accelerated molecular dynamics (aMD) to improve the conformational sampling over conventional molecular dynamics techniques. In the original aMD implementation, sampling is greatly improved by raising energy wells below a predefined energy level. Recently, our group presented an alternative aMD implementation where simulations are accelerated by lowering energy barriers of the potential energy surface. When coupled with thermodynamic integration simulations, this implementation showed very promising results. However, when applied to large systems, such as proteins, the simulation tends to be biased to high energy regions of the potential landscape. The reason for this behavior lies in the boost equation used since the highest energy barriers are dramatically more affected than the lower ones. To address this issue, in this work, we present a new boost equation that prevents oversampling of unfavorable high energy conformational states. The new boost potential provides not only better recovery of statistics throughout the simulation but also enhanced sampling of statistically relevant regions in explicit solvent MD simulations. PMID:22241967

  16. Energy Management of Manned Boost-Glide Vehicles: A Historical Perspective

    NASA Technical Reports Server (NTRS)

    Day, Richard E.

    2004-01-01

    As flight progressed from propellers to jets to rockets, the propulsive energy grew exponentially. With the development of rocket-only boosted vehicles, energy management of these boost-gliders became a distinct requirement for the unpowered return to base, alternate landing site, or water-parachute landing, starting with the X-series rocket aircraft and terminating with the present-day Shuttle. The problem presented here consists of: speed (kinetic energy) - altitude (potential energy) - steep glide angles created by low lift-to-drag ratios (L/D) - distance to landing site - and the bothersome effects of the atmospheric characteristics varying with altitude. The primary discussion regards post-boost, stabilized glides; however, the effects of centrifugal and geopotential acceleration are discussed as well. The aircraft and spacecraft discussed here are the X-1, X-2, X-15, and the Shuttle; and to a lesser, comparative extent, Mercury, Gemini, Apollo, and lifting bodies. The footprints, landfalls, and methods developed for energy management are also described. The essential tools required for energy management - simulator planning, instrumentation, radar, telemetry, extended land or water range, Mission Control Center (with specialist controllers), and emergency alternate landing sites - were first established through development of early concepts and were then validated by research flight tests.

  17. Changes in the TRMM Version-5 and Version-6 Precipitation Radar Products Due to Orbit Boost

    NASA Technical Reports Server (NTRS)

    Liao, Liang; Meneghini, Robert

    2010-01-01

    The performance of the version-5 and version-6 Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) products before and after the satellite orbit boost is assessed through a series of comparisons with Weather Surveillance Radar (WSR)-88D ground-based radar in Melbourne, Florida. Analysis of the comparisons of radar reflectivity near the storm top from the ground radar and both versions of the PR indicates that the PR bias relative to the WSR radar at Melbourne is on the order of 1dB for both pre- and post-boost periods, indicating that the PR products maintain accurate calibration after the orbit boost. Comparisons with the WSR-88D near-surface reflectivity factors indicate that both versions of the PR products accurately correct for attenuation in stratiform rain. However, in convective rain, both versions exhibit negative biases in the near-surface radar reflectivity with version-6 products having larger negative biases than version-5. Rain rate comparisons between the ground and space radars show similar characteristics

  18. "Boosting" in Paralympic athletes with spinal cord injury: doping without drugs.

    PubMed

    Mazzeo, Filomena; Santamaria, Stefania; Iavarone, Alessandro

    2015-01-01

    The intentional activation of autonomic dysreflexia (AD, also called "boosting"), a practice sometimes used by athletes affected by spinal cord injury (SCI), is banned by the International Paralympic Committee (IPC). Although various studies have addressed doping and AD as separate issues, studies evaluating AD as a doping method are lacking. The aim of this brief review is to contribute to better understanding of the relationship between doping and AD. We conducted a literature search of the PubMed database (from 1994 onwards). The key search terms "autonomic dysreflexia" and "boosting" were crossreferenced with "sport performance". The official Paralympic website was also viewed. AD is a potent sympathetic reflex, due to a massive release of noradrenaline, that results in marked vasoconstriction distal to the level of the lesion. Athletes with SCI often self-inflict physical suffering in order to induce this phenomenon, which carries high health risks (i.e., hypertension, cerebral hemorrhage, stroke and sudden death). Boosting is a practice that can be compared to doping methods and the IPC expressly prohibits it. Any deliberate attempt to induce AD, if detected, will lead to disqualification from the sporting event and subsequent investigation by the IPC Legal and Ethics Committee.

  19. Modeling boost performance using a two dimensional implementation of the targeting task performance metric

    NASA Astrophysics Data System (ADS)

    Preece, Bradley L.; Haefner, David P.; Fanning, Jonathan D.

    2012-06-01

    Using post-processing filters to enhance image detail, a process commonly referred to as boost, can significantly affect the performance of an EO/IR system. The US Army's target acquisition models currently use the Targeting Task Performance (TTP) metric to quantify sensor performance. The TTP metric accounts for each element in the system including: blur and noise introduced by the imager, any additional post-processing steps, and the effects of the Human Visual System (HVS). The current implementation of the TTP metric assumes spatial separability, which can introduce significant errors when the TTP is applied to systems using non-separable filters. To accurately apply the TTP metric to systems incorporating boost, we have implement a two-dimensional (2D) version of the TTP metric. The accuracy of the 2D TTP metric was verified through a series of perception experiments involving various levels of boost. The 2D TTP metric has been incorporated into the Night Vision Integrated Performance Model (NV-IPM) allowing accurate system modeling of non-separable image filters.

  20. Experience in fractionated stereotactic body radiation therapy boost for newly diagnosed nasopharyngeal carcinoma

    SciTech Connect

    Chen, Helen H.W.; Tsai, S.-T.; Wang, M.-S.; Wu, Y.-H.; Hsueh, W.-T.; Yang, M.-W.; Yeh, I-C.; Lin, J.-C. . E-mail: jclin@vghtc.gov.tw

    2006-12-01

    Purpose: Radiotherapy is the most effective treatment for nasopharyngeal carcinoma (NPC). The aim of this study is to evaluate the efficacy and toxicity of fractionated stereotactic body radiation therapy (SBRT) boost for NPC. Methods and Materials: Sixty-four patients with newly diagnosed, nonmetastatic NPC were treated with conventional radiotherapy 64.8-68.4 Gy followed by fractionated SBRT boost 12-15 Gy between January 2002 and July 2004. Most patients (72%) presented with Stage III-IV disease. Fifty-two patients also received cisplatin-based concurrent (38) or neoadjuvant (14) chemotherapy. The major endpoints were local control, overall survival, and complications. Results: All patients finished the planned dose of radiotherapy. After a median follow-up of 31 months (range, 22-54), 15 patients developed tumor recurrences-3 in the nasopharynx, 4 in the neck, 5 in distant sites, 1 in both nasopharynx and neck, 2 in the neck and a distant site. The 3-year actuarial rate of local control was 93.1%, regional control 91.4%, freedom from distant metastasis 90.3%, and overall survival 84.9%, respectively. There were no Grade 4 acute or chronic radiation-related complications. Conclusions: Fractionated SBRT boost for NPC is technically feasible and provides good local control without any severe complications.

  1. An effective DNA priming-protein boosting approach for the cervical cancer vaccination.

    PubMed

    Kianmehr, Zahra; Ardestani, Susan K; Soleimanjahi, Hoorieh; Farahmand, Behrokh; Abdoli, Asghar; Khatami, Maryam; Akbari, Khadijeh; Fotouhi, Fatemeh

    2015-03-01

    Considerable advances have been made in developing human papillomaviruses (HPV) prophylactic vaccines based on L1 virus-like particles (VLPs). However, there are limitations in the availability of these vaccines in developing countries, where most cases of cervical cancer occur. In the current study, the prime-boost immunization strategies were studied using a DNA vaccine carrying HPV-16 L1 gene (pcDNA/L1) and insect cell baculovirus-derived HPV-16 L1 VLP. The humoral immunity was evaluated by measuring the specific IgG levels, and the T-cell immune response was assessed by measuring different cytokines such as IFN-γ, TNF-α and IL-10. Results showed that although immunization with pcDNA/L1 alone could induce strong cellular immune responses, higher immunogenicity especially antibody response was achieved in pcDNA/L1 priming-VLP boosting regimen. Therefore, we suggest that prime-boost regimen can be considered as an efficient prophylactic and therapeutic vaccine.

  2. An Optimal t-{Delta}v Guidance Law for Intercepting a Boosting Target

    SciTech Connect

    Ng, L.C.; Breitfeller, E.; Ledebuhr, A.G.

    2002-06-30

    Lawrence Livermore National Laboratory (LLNL) have developed a new missile guidance law for intercepting a missile during boost phase. Unlike other known missile guidance laws being used today, the new t-{Delta}v guidance law optimally trades an interceptor's onboard fuel capacity against time-to-go before impact. In particular, this guidance law allows a missile designer to program the interceptor to maximally impact a boosting missile before burnout or burn termination and thus negating its ability to achieve the maximum kinetic velocity. For an intercontinental range ballistic missile (ICBM), it can be shown that for every second of earlier intercept prior to burnout, the ICBM ground range is reduced by 350 km. Therefore, intercepting a mere 15 seconds earlier would result in amiss of 5,250 km from the intended target or approximately a distance across the continental US. This paper also shows how the t-{Delta}v guidance law can incorporate uncertainties in target burnout time, predicted intercept point (PIP) error, time-to-go error, and other track estimation errors. The authors believe that the t-{Delta}v guidance law is a step toward the development of a new and smart missile guidance law that would enhance the probability of achieving a boost phase intercept.

  3. A Boosting Algorithm for Estimating Generalized Propensity Scores with Continuous Treatments

    PubMed Central

    Coffman, Donna L.; Ghosh, Debashis

    2015-01-01

    In this article, we study the causal inference problem with a continuous treatment variable using propensity score-based methods. For a continuous treatment, the generalized propensity score is defined as the conditional density of the treatment-level given covariates (confounders). The dose–response function is then estimated by inverse probability weighting, where the weights are calculated from the estimated propensity scores. When the dimension of the covariates is large, the traditional nonparametric density estimation suffers from the curse of dimensionality. Some researchers have suggested a two-step estimation procedure by first modeling the mean function. In this study, we suggest a boosting algorithm to estimate the mean function of the treatment given covariates. In boosting, an important tuning parameter is the number of trees to be generated, which essentially determines the trade-off between bias and variance of the causal estimator. We propose a criterion called average absolute correlation coefficient (AACC) to determine the optimal number of trees. Simulation results show that the proposed approach performs better than a simple linear approximation or L2 boosting. The proposed methodology is also illustrated through the Early Dieting in Girls study, which examines the influence of mothers’ overall weight concern on daughters’ dieting behavior. PMID:26877909

  4. Application of SCR priming VLP boosting as a novel vaccination strategy against HIV-1.

    PubMed

    Sadat, Seyed Mehdi; Zabihollahi, Rezvan; Aghasadeghi, Mohammad Reza; Vahabpour, Rouhollah; Siadat, Seyed Davar; Memarnejadian, Arash; Azadmanesh, Kayhan; Parivar, Kazem

    2011-04-01

    Human immunodeficiency virus infection is a worldwide health problem and a protective vaccine is desperately needed to control the AIDS pandemics. To address this concern, we previously constructed single-cycle replicable (SCR) HIV-1 virions, which completely maintained the antigenic structures of HIV-1. Herein, to optimize a vaccination strategy, we studied the immunogenicity of produced SCR virions and adjuvant-formulated HIV-1 virus-like particles (VLPs) in homologous and heterologous prime-boosting regimens. Accordingly, BALB/c mice received three doses of immunogens in 3-week intervals and their immune responses were evaluated using ELISA, cytokine and IFN-γ ELISpot assays. These analyses not only indicated the superiority of SCR prime-VLP boosting for strong induction of specific IFN-γ producing cells, but also showed the capability of this strategy over the others for better stimulation of humoral response, which was evidenced with the detection of highest titer of total IgG against HIV ENV glycoprotein. Furthermore, determination of IgG subclasses and IFN-γ/IL4 secretion ratio in cultured splenocytes demonstrated the efficient augmentation of mixed responses with the dominancy of Th1 immunity following SCR/VLP immunization strategy. Our results additionally pointed towards the applicability of Montanide ISA 720 + CpG as a potent Th1-directing adjuvant mixture. Overall, this study suggests SCR prime-VLP boosting as a promising approach in HIV vaccine development.

  5. A Defined Tuberculosis Vaccine Candidate Boosts BCG and Protects Against Multidrug Resistant Mycobacterium tuberculosis

    PubMed Central

    Bertholet, Sylvie; Ireton, Gregory C.; Ordway, Diane J.; Windish, Hillarie Plessner; Pine, Samuel O.; Kahn, Maria; Phan, Tony; Orme, Ian M.; Vedvick, Thomas S.; Baldwin, Susan L.; Coler, Rhea N.; Reed, Steven G.

    2011-01-01

    Despite the widespread use of Mycobacterium bovis bacillus Calmette-Guerin (BCG) childhood vaccine, tuberculosis (TB) remains a serious global health problem. A successful vaccine against TB that replaces or boosts BCG will include antigens that induce or recall appropriate T cell responses. Four Mycobacterium tuberculosis (Mtb) antigens, including members of the virulence factor families PE/PPE and EsX, or antigens associated with latency were produced as a single recombinant fusion protein. When administered with the adjuvant GLA-SE, a stable oil-in-water nanoemulsion, the fusion protein ID93 was immunogenic in mice, guinea pigs, and cynomolgus monkeys. In mice, ID93/GLA-SE combination induced polyfunctional CD4 TH1-cell responses characterized by antigen-specific IFN-gamma, tumor necrosis factor and interleukin-2, as well as a reduction in the number of bacteria in the lungs of animals subsequently infected with virulent or multidrug resistant Mtb strains. Furthermore, boosting BCG-vaccinated guinea pigs with ID93/GLA-SE resulted in reduced pathology and fewer bacilli, and prevented the death of animals challenged with virulent Mtb. Finally, ID93 elicited polyfunctional effector CD4 and CD8 T-cell responses in BCG-vaccinated or Mtb-exposed human peripheral blood mononuclear cells. This study establishes that the protein subunit vaccine ID93/GLA-SE protects against TB and MDR-TB in animals, and is a candidate for boosting the protective efficacy of the childhood BCG vaccine. PMID:20944089

  6. Technology transfer for adaptation

    NASA Astrophysics Data System (ADS)

    Biagini, Bonizella; Kuhl, Laura; Gallagher, Kelly Sims; Ortiz, Claudia

    2014-09-01

    Technology alone will not be able to solve adaptation challenges, but it is likely to play an important role. As a result of the role of technology in adaptation and the importance of international collaboration for climate change, technology transfer for adaptation is a critical but understudied issue. Through an analysis of Global Environment Facility-managed adaptation projects, we find there is significantly more technology transfer occurring in adaptation projects than might be expected given the pessimistic rhetoric surrounding technology transfer for adaptation. Most projects focused on demonstration and early deployment/niche formation for existing technologies rather than earlier stages of innovation, which is understandable considering the pilot nature of the projects. Key challenges for the transfer process, including technology selection and appropriateness under climate change, markets and access to technology, and diffusion strategies are discussed in more detail.

  7. Origins of adaptive immunity.

    PubMed

    Liongue, Clifford; John, Liza B; Ward, Alister

    2011-01-01

    Adaptive immunity, involving distinctive antibody- and cell-mediated responses to specific antigens based on "memory" of previous exposure, is a hallmark of higher vertebrates. It has been argued that adaptive immunity arose rapidly, as articulated in the "big bang theory" surrounding its origins, which stresses the importance of coincident whole-genome duplications. Through a close examination of the key molecules and molecular processes underpinning adaptive immunity, this review suggests a less-extreme model, in which adaptive immunity emerged as part of longer evolutionary journey. Clearly, whole-genome duplications provided additional raw genetic materials that were vital to the emergence of adaptive immunity, but a variety of other genetic events were also required to generate some of the key molecules, whereas others were preexisting and simply co-opted into adaptive immunity.

  8. Adaptation and visual coding

    PubMed Central

    Webster, Michael A.

    2011-01-01

    Visual coding is a highly dynamic process and continuously adapting to the current viewing context. The perceptual changes that result from adaptation to recently viewed stimuli remain a powerful and popular tool for analyzing sensory mechanisms and plasticity. Over the last decade, the footprints of this adaptation have been tracked to both higher and lower levels of the visual pathway and over a wider range of timescales, revealing that visual processing is much more adaptable than previously thought. This work has also revealed that the pattern of aftereffects is similar across many stimulus dimensions, pointing to common coding principles in which adaptation plays a central role. However, why visual coding adapts has yet to be fully answered. PMID:21602298

  9. Parallel Anisotropic Tetrahedral Adaptation

    NASA Technical Reports Server (NTRS)

    Park, Michael A.; Darmofal, David L.

    2008-01-01

    An adaptive method that robustly produces high aspect ratio tetrahedra to a general 3D metric specification without introducing hybrid semi-structured regions is presented. The elemental operators and higher-level logic is described with their respective domain-decomposed parallelizations. An anisotropic tetrahedral grid adaptation scheme is demonstrated for 1000-1 stretching for a simple cube geometry. This form of adaptation is applicable to more complex domain boundaries via a cut-cell approach as demonstrated by a parallel 3D supersonic simulation of a complex fighter aircraft. To avoid the assumptions and approximations required to form a metric to specify adaptation, an approach is introduced that directly evaluates interpolation error. The grid is adapted to reduce and equidistribute this interpolation error calculation without the use of an intervening anisotropic metric. Direct interpolation error adaptation is illustrated for 1D and 3D domains.

  10. Origins of adaptive immunity.

    PubMed

    Liongue, Clifford; John, Liza B; Ward, Alister

    2011-01-01

    Adaptive immunity, involving distinctive antibody- and cell-mediated responses to specific antigens based on "memory" of previous exposure, is a hallmark of higher vertebrates. It has been argued that adaptive immunity arose rapidly, as articulated in the "big bang theory" surrounding its origins, which stresses the importance of coincident whole-genome duplications. Through a close examination of the key molecules and molecular processes underpinning adaptive immunity, this review suggests a less-extreme model, in which adaptive immunity emerged as part of longer evolutionary journey. Clearly, whole-genome duplications provided additional raw genetic materials that were vital to the emergence of adaptive immunity, but a variety of other genetic events were also required to generate some of the key molecules, whereas others were preexisting and simply co-opted into adaptive immunity. PMID:21395512

  11. Gravitational adaptation of animals

    NASA Technical Reports Server (NTRS)

    Smith, A. H.; Burton, R. R.

    1982-01-01

    The effect of gravitational adaptation is studied in a group of five Leghorn cocks which had become physiologically adapted to 2 G after 162 days of centrifugation. After this period of adaptation, they are periodically exposed to a 2 G field, accompanied by five previously unexposed hatch-mates, and the degree of retained acceleration adaptation is estimated from the decrease in lymphocyte frequency after 24 hr at 2 G. Results show that the previously adapted birds exhibit an 84% greater lymphopenia than the unexposed birds, and that the lymphocyte frequency does not decrease to a level below that found at the end of 162 days at 2 G. In addition, the capacity for adaptation to chronic acceleration is found to be highly heritable. An acceleration tolerant strain of birds shows lesser mortality during chronic acceleration, particularly in intermediate fields, although the result of acceleration selection is largely quantitative (a greater number of survivors) rather than qualitative (behavioral or physiological changes).

  12. Experimental adaptive Bayesian tomography

    NASA Astrophysics Data System (ADS)

    Kravtsov, K. S.; Straupe, S. S.; Radchenko, I. V.; Houlsby, N. M. T.; Huszár, F.; Kulik, S. P.

    2013-06-01

    We report an experimental realization of an adaptive quantum state tomography protocol. Our method takes advantage of a Bayesian approach to statistical inference and is naturally tailored for adaptive strategies. For pure states, we observe close to N-1 scaling of infidelity with overall number of registered events, while the best nonadaptive protocols allow for N-1/2 scaling only. Experiments are performed for polarization qubits, but the approach is readily adapted to any dimension.

  13. Adaptive Pairing Reversible Watermarking.

    PubMed

    Dragoi, Ioan-Catalin; Coltuc, Dinu

    2016-05-01

    This letter revisits the pairwise reversible watermarking scheme of Ou et al., 2013. An adaptive pixel pairing that considers only pixels with similar prediction errors is introduced. This adaptive approach provides an increased number of pixel pairs where both pixels are embedded and decreases the number of shifted pixels. The adaptive pairwise reversible watermarking outperforms the state-of-the-art low embedding bit-rate schemes proposed so far.

  14. Adaptation as organism design

    PubMed Central

    Gardner, Andy

    2009-01-01

    The problem of adaptation is to explain the apparent design of organisms. Darwin solved this problem with the theory of natural selection. However, population geneticists, whose responsibility it is to formalize evolutionary theory, have long neglected the link between natural selection and organismal design. Here, I review the major historical developments in theory of organismal adaptation, clarifying what adaptation is and what it is not, and I point out future avenues for research. PMID:19793739

  15. Digital adaptive sampling.

    NASA Technical Reports Server (NTRS)

    Breazeale, G. J.; Jones, L. E.

    1971-01-01

    Discussion of digital adaptive sampling, which is consistently better than fixed sampling in noise-free cases. Adaptive sampling is shown to be feasible and, it is considered, should be studied further. It should be noted that adaptive sampling is a class of variable rate sampling in which the variability depends on system signals. Digital rather than analog laws should be studied, because cases can arise in which the analog signals are not even available. An extremely important problem is implementation.

  16. Image guidance using 3D-ultrasound (3D-US) for daily positioning of lumpectomy cavity for boost irradiation

    PubMed Central

    2011-01-01

    Purpose The goal of this study was to evaluate the use of 3D ultrasound (3DUS) breast IGRT for electron and photon lumpectomy site boost treatments. Materials and methods 20 patients with a prescribed photon or electron boost were enrolled in this study. 3DUS images were acquired both at time of simulation, to form a coregistered CT/3DUS dataset, and at the time of daily treatment delivery. Intrafractional motion between treatment and simulation 3DUS datasets were calculated to determine IGRT shifts. Photon shifts were evaluated isocentrically, while electron shifts were evaluated in the beam's-eye-view. Volume differences between simulation and first boost fraction were calculated. Further, to control for the effect of change in seroma/cavity volume due to time lapse between the 2 sets of images, interfraction IGRT shifts using the first boost fraction as reference for all subsequent treatment fractions were also calculated. Results For photon boosts, IGRT shifts were 1.1 ± 0.5 cm and 50% of fractions required a shift >1.0 cm. Volume change between simulation and boost was 49 ± 31%. Shifts when using the first boost fraction as reference were 0.8 ± 0.4 cm and 24% required a shift >1.0 cm. For electron boosts, shifts were 1.0 ± 0.5 cm and 52% fell outside the dosimetric penumbra. Interfraction analysis relative to the first fraction noted the shifts to be 0.8 ± 0.4 cm and 36% fell outside the penumbra. Conclusion The lumpectomy cavity can shift significantly during fractionated radiation therapy. 3DUS can be used to image the cavity and correct for interfractional motion. Further studies to better define the protocol for clinical application of IGRT in breast cancer is needed. PMID:21554697

  17. Quantifying the Adaptive Cycle.

    PubMed

    Angeler, David G; Allen, Craig R; Garmestani, Ahjond S; Gunderson, Lance H; Hjerne, Olle; Winder, Monika

    2015-01-01

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994-2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems. PMID:26716453

  18. Quantifying the adaptive cycle

    USGS Publications Warehouse

    Angeler, David G.; Allen, Craig R.; Garmestani, Ahjond S.; Gunderson, Lance H.; Hjerne, Olle; Winder, Monika

    2015-01-01

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994–2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems.

  19. Human adaptation to smog

    SciTech Connect

    Evans, G.W. Jacobs, S.V.; Frager, N.B.

    1982-10-01

    This study examined the health effects of human adaptation to photochemical smog. A group of recent arrivals to the Los Angeles air basin were compared to long-term residents of the basin. Evidence for adaptation included greater irritation and respiratory problems among the recent arrivals and desensitization among the long-term residents in their judgments of the severity of the smog problem to their health. There was no evidence for biochemical adaptation as measured by hemoglobin response to oxidant challenge. The results were discussed in terms of psychological adaption to chronic environmental stressors.

  20. Adaptive parallel logic networks

    NASA Technical Reports Server (NTRS)

    Martinez, Tony R.; Vidal, Jacques J.

    1988-01-01

    Adaptive, self-organizing concurrent systems (ASOCS) that combine self-organization with massive parallelism for such applications as adaptive logic devices, robotics, process control, and system malfunction management, are presently discussed. In ASOCS, an adaptive network composed of many simple computing elements operating in combinational and asynchronous fashion is used and problems are specified by presenting if-then rules to the system in the form of Boolean conjunctions. During data processing, which is a different operational phase from adaptation, the network acts as a parallel hardware circuit.

  1. Quantifying the Adaptive Cycle

    PubMed Central

    Angeler, David G.; Allen, Craig R.; Garmestani, Ahjond S.; Gunderson, Lance H.; Hjerne, Olle; Winder, Monika

    2015-01-01

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994–2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems. PMID:26716453

  2. Decentralized adaptive control

    NASA Technical Reports Server (NTRS)

    Oh, B. J.; Jamshidi, M.; Seraji, H.

    1988-01-01

    A decentralized adaptive control is proposed to stabilize and track the nonlinear, interconnected subsystems with unknown parameters. The adaptation of the controller gain is derived by using model reference adaptive control theory based on Lyapunov's direct method. The adaptive gains consist of sigma, proportional, and integral combination of the measured and reference values of the corresponding subsystem. The proposed control is applied to the joint control of a two-link robot manipulator, and the performance in computer simulation corresponds with what is expected in theoretical development.

  3. DC-AC Cascaded H-Bridge Multilevel Boost Inverter With No Inductors for Electric/Hybrid Electric Vehicle Applications

    SciTech Connect

    Tolbert, Leon M; Ozpineci, Burak; Du, Zhong; Chiasson, John N

    2009-01-01

    This paper presents a cascaded H-bridge multilevel boost inverter for electric vehicle (EV) and hybrid EV (HEV) applications implemented without the use of inductors. Currently available power inverter systems for HEVs use a dc-dc boost converter to boost the battery voltage for a traditional three-phase inverter. The present HEV traction drive inverters have low power density, are expensive, and have low efficiency because they need a bulky inductor. A cascaded H-bridge multilevel boost inverter design for EV and HEV applications implemented without the use of inductors is proposed in this paper. Traditionally, each H-bridge needs a dc power supply. The proposed design uses a standard three-leg inverter (one leg for each phase) and an H-bridge in series with each inverter leg which uses a capacitor as the dc power source. A fundamental switching scheme is used to do modulation control and to produce a five-level phase voltage. Experiments show that the proposed dc-ac cascaded H-bridge multilevel boost inverter can output a boosted ac voltage without the use of inductors.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  5. Physiologic adaptation to space - Space adaptation syndrome

    NASA Technical Reports Server (NTRS)

    Vanderploeg, J. M.

    1985-01-01

    The adaptive changes of the neurovestibular system to microgravity, which result in space motion sickness (SMS), are studied. A list of symptoms, which range from vomiting to drowsiness, is provided. The two patterns of symptom development, rapid and gradual, and the duration of the symptoms are described. The concept of sensory conflict and rearrangements to explain SMS is being investigated.

  6. Boosting BCG-primed responses with a subunit Apa vaccine during the waning phase improves immunity and imparts protection against Mycobacterium tuberculosis.

    PubMed

    Nandakumar, Subhadra; Kannanganat, Sunil; Dobos, Karen M; Lucas, Megan; Spencer, John S; Amara, Rama Rao; Plikaytis, Bonnie B; Posey, James E; Sable, Suraj B

    2016-01-01

    Heterologous prime-boosting has emerged as a powerful vaccination approach against tuberculosis. However, optimal timing to boost BCG-immunity using subunit vaccines remains unclear in clinical trials. Here, we followed the adhesin Apa-specific T-cell responses in BCG-primed mice and investigated its BCG-booster potential. The Apa-specific T-cell response peaked 32-52 weeks after parenteral or mucosal BCG-priming but waned significantly by 78 weeks. A subunit-Apa-boost during the contraction-phase of BCG-response had a greater effect on the magnitude and functional quality of specific cellular and humoral responses compared to a boost at the peak of BCG-response. The cellular response increased following mucosal BCG-prime-Apa-subunit-boost strategy compared to Apa-subunit-prime-BCG-boost approach. However, parenteral BCG-prime-Apa-subunit-boost by a homologous route was the most effective strategy in-terms of enhancing specific T-cell responses during waning in the lung and spleen. Two Apa-boosters markedly improved waning BCG-immunity and significantly reduced Mycobacterium tuberculosis burdens post-challenge. Our results highlight the challenges of optimization of prime-boost regimens in mice where BCG drives persistent immune-activation and suggest that boosting with a heterologous vaccine may be ideal once the specific persisting effector responses are contracted. Our results have important implications for design of prime-boost regimens against tuberculosis in humans. PMID:27173443

  7. Boosting BCG-primed responses with a subunit Apa vaccine during the waning phase improves immunity and imparts protection against Mycobacterium tuberculosis.

    PubMed

    Nandakumar, Subhadra; Kannanganat, Sunil; Dobos, Karen M; Lucas, Megan; Spencer, John S; Amara, Rama Rao; Plikaytis, Bonnie B; Posey, James E; Sable, Suraj B

    2016-05-13

    Heterologous prime-boosting has emerged as a powerful vaccination approach against tuberculosis. However, optimal timing to boost BCG-immunity using subunit vaccines remains unclear in clinical trials. Here, we followed the adhesin Apa-specific T-cell responses in BCG-primed mice and investigated its BCG-booster potential. The Apa-specific T-cell response peaked 32-52 weeks after parenteral or mucosal BCG-priming but waned significantly by 78 weeks. A subunit-Apa-boost during the contraction-phase of BCG-response had a greater effect on the magnitude and functional quality of specific cellular and humoral responses compared to a boost at the peak of BCG-response. The cellular response increased following mucosal BCG-prime-Apa-subunit-boost strategy compared to Apa-subunit-prime-BCG-boost approach. However, parenteral BCG-prime-Apa-subunit-boost by a homologous route was the most effective strategy in-terms of enhancing specific T-cell responses during waning in the lung and spleen. Two Apa-boosters markedly improved waning BCG-immunity and significantly reduced Mycobacterium tuberculosis burdens post-challenge. Our results highlight the challenges of optimization of prime-boost regimens in mice where BCG drives persistent immune-activation and suggest that boosting with a heterologous vaccine may be ideal once the specific persisting effector responses are contracted. Our results have important implications for design of prime-boost regimens against tuberculosis in humans.

  8. Boosting BCG-primed responses with a subunit Apa vaccine during the waning phase improves immunity and imparts protection against Mycobacterium tuberculosis

    PubMed Central

    Nandakumar, Subhadra; Kannanganat, Sunil; Dobos, Karen M.; Lucas, Megan; Spencer, John S.; Amara, Rama Rao; Plikaytis, Bonnie B.; Posey, James E.; Sable, Suraj B.

    2016-01-01

    Heterologous prime–boosting has emerged as a powerful vaccination approach against tuberculosis. However, optimal timing to boost BCG-immunity using subunit vaccines remains unclear in clinical trials. Here, we followed the adhesin Apa-specific T-cell responses in BCG-primed mice and investigated its BCG-booster potential. The Apa-specific T-cell response peaked 32–52 weeks after parenteral or mucosal BCG-priming but waned significantly by 78 weeks. A subunit-Apa-boost during the contraction-phase of BCG-response had a greater effect on the magnitude and functional quality of specific cellular and humoral responses compared to a boost at the peak of BCG-response. The cellular response increased following mucosal BCG-prime–Apa-subunit-boost strategy compared to Apa-subunit-prime–BCG-boost approach. However, parenteral BCG-prime–Apa-subunit-boost by a homologous route was the most effective strategy in-terms of enhancing specific T-cell responses during waning in the lung and spleen. Two Apa-boosters markedly improved waning BCG-immunity and significantly reduced Mycobacterium tuberculosis burdens post-challenge. Our results highlight the challenges of optimization of prime–boost regimens in mice where BCG drives persistent immune-activation and suggest that boosting with a heterologous vaccine may be ideal once the specific persisting effector responses are contracted. Our results have important implications for design of prime–boost regimens against tuberculosis in humans. PMID:27173443

  9. The adaptive deep brain stimulation challenge.

    PubMed

    Arlotti, Mattia; Rosa, Manuela; Marceglia, Sara; Barbieri, Sergio; Priori, Alberto

    2016-07-01

    Sub-optimal clinical outcomes of conventional deep brain stimulation (cDBS) in treating Parkinson's Disease (PD) have boosted the development of new solutions to improve DBS therapy. Adaptive DBS (aDBS), consisting of closed-loop, real-time changing of stimulation parameters according to the patient's clinical state, promises to achieve this goal and is attracting increasing interest in overcoming all of the challenges posed by its development and adoption. In the design, implementation, and application of aDBS, the choice of the control variable and of the control algorithm represents the core challenge. The proposed approaches, in fact, differ in the choice of the control variable and control policy, in the system design and its technological limits, in the patient's target symptom, and in the surgical procedure needed. Here, we review the current proposals for aDBS systems, focusing on the choice of the control variable and its advantages and drawbacks, thus providing a general overview of the possible pathways for the clinical translation of aDBS with its benefits, limitations and unsolved issues. PMID:27079257

  10. Coherent optical adaptive techniques.

    PubMed

    Bridges, W B; Brunner, P T; Lazzara, S P; Nussmeier, T A; O'Meara, T R; Sanguinet, J A; Brown, W P

    1974-02-01

    The theory of multidither adaptive optical radar phased arrays is briefly reviewed as an introduction to the experimental results obtained with seven-element linear and three-element triangular array systems operating at 0.6328 microm. Atmospheric turbulence compensation and adaptive tracking capabilities are demonstrated.

  11. Research, Adaptation, & Change.

    ERIC Educational Resources Information Center

    Morris, Lee A., Ed.; And Others

    Research adaptation is an endeavor that implies solid collaboration among school practitioners and university and college researchers. This volume addresses the broad issues of research as an educational endeavor, adaptation as a necessary function associated with applying research findings to school situations, and change as an inevitable…

  12. Uncertainty in adaptive capacity

    NASA Astrophysics Data System (ADS)

    Adger, W. Neil; Vincent, Katharine

    2005-03-01

    The capacity to adapt is a critical element of the process of adaptation: it is the vector of resources that represent the asset base from which adaptation actions can be made. Adaptive capacity can in theory be identified and measured at various scales, from the individual to the nation. The assessment of uncertainty within such measures comes from the contested knowledge domain and theories surrounding the nature of the determinants of adaptive capacity and the human action of adaptation. While generic adaptive capacity at the national level, for example, is often postulated as being dependent on health, governance and political rights, and literacy, and economic well-being, the determinants of these variables at national levels are not widely understood. We outline the nature of this uncertainty for the major elements of adaptive capacity and illustrate these issues with the example of a social vulnerability index for countries in Africa. To cite this article: W.N. Adger, K. Vincent, C. R. Geoscience 337 (2005).

  13. [Postvagotomy adaptation syndrome].

    PubMed

    Shapovalov, V A

    1998-01-01

    It was established in experiment, that the changes of the natural resistance of organism indexes and of the peritoneal cavity cytology has compensatory-adaptational character while the denervation-adaptational syndrome occurrence and progress, which may be assessed as eustress. Vagotomy and operative trauma cause qualitatively different reactions of an organism.

  14. Adaptive Sampling Proxy Application

    2012-10-22

    ASPA is an implementation of an adaptive sampling algorithm [1-3], which is used to reduce the computational expense of computer simulations that couple disparate physical scales. The purpose of ASPA is to encapsulate the algorithms required for adaptive sampling independently from any specific application, so that alternative algorithms and programming models for exascale computers can be investigated more easily.

  15. Water Resource Adaptation Program

    EPA Science Inventory

    The Water Resource Adaptation Program (WRAP) contributes to the U.S. Environmental Protection Agency’s (U.S. EPA) efforts to provide water resource managers and decision makers with the tools needed to adapt water resources to demographic and economic development, and future clim...

  16. Retinal Imaging: Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Goncharov, A. S.; Iroshnikov, N. G.; Larichev, Andrey V.

    This chapter describes several factors influencing the performance of ophthalmic diagnostic systems with adaptive optics compensation of human eye aberration. Particular attention is paid to speckle modulation, temporal behavior of aberrations, and anisoplanatic effects. The implementation of a fundus camera with adaptive optics is considered.

  17. Impact of switching from lopinavir/ritonavir to boosted and un-boosted atazanavir on glucose metabolism: the ATAzanavir & GLUcose metabolism (ATAGLU) study.

    PubMed

    d'Ettorre, Gabriella; Ceccarelli, Giancarlo; Zaccarelli, Mauro; Ascoli-Bartoli, Tommaso; Bianchi, Luigi; Bellelli, Valeria; De Girolamo, Gabriella; Serafino, Sara; Giustini, Noemi; Mastroianni, Claudio M; Vullo, Vincenzo

    2016-07-01

    Previous studies have reported that protease inhibitors (PIs) can contribute to glycaemic alterations. However, there are few trials examining the direct effect of a single PI. The objective of the study was to evaluate the modifications of glucose and lipid profiles after a switch from lopinavir/ritonavir (LPV/r) to atazanavir, used as ritonavir-boosted (ATV/r) or un-boosted. We conducted a retrospective observational cohort study on the effect of ATV/(r) on glycaemic metabolism (ATAGLU) in patients with undetectable levels of HIV-RNA who switched from LPV/r. In total, 235 patients treated for 48 weeks with LPV/r plus two nucleoside reverse transcriptase inhibitors (NRTIs) and with undetectable HIV-RNA were included: 134 continued LPV/r after the initial 48 weeks and 101 switched to ATV(/r) (18.3% to ATV; 24.7% to ATV/r). A significant decrease in mean glucose level and insulin resistance was observed in patients who switched to ATV(/r). The mean cholesterol triglyceride levels increased in the LPV/r group and decreased among the patients who switched. A significant increase of CD4 T cells with undetectable levels of HIV-RNA was observed in all groups. The long-term results obtained in this real-life study suggest that patients who have achieved initial suppression on a regimen including LPV/r + two NRTIs can switch to ATV/(r) + two NRTIs with an improvement in lipid and glycaemic metabolism.

  18. Evaluation of the immune response elicited by vaccination with viral vectors encoding FMDV capsid proteins and boosted with inactivated virus.

    PubMed

    Romanutti, Carina; D'Antuono, Alejandra; Palacios, Carlos; Quattrocchi, Valeria; Zamorano, Patricia; La Torre, Jose; Mattion, Nora

    2013-08-30

    The aim of the present study was to assess the effect of introducing a priming step with replication-defective viral vectors encoding the capsid proteins of FMDV, followed by a boost with killed virus vaccines, using a suitable BALB/c mice model. Additionally, the immune response to other combined vector immunization regimens was studied. For this purpose, we analyzed different prime-boost immunizations with recombinant adenovirus (Ad), herpesvirus amplicons (Hs) and/or killed virus (KV) vaccines. The highest antibody titers were found in the group that received two doses of adjuvanted KV (P<0.002). Antibody titers were higher in those groups receiving a mixed regimen of vectors, compared to immunization with either vector alone (P<0.0001). Priming with any of the viral vectors induced a shift of the cytokine balance toward a Th1 type immune response regardless of the delivery system used for boosting. The highest IgG1 titer was induced by two doses of adjuvanted KV (P=0.0002) and the highest IgG2a titer corresponded to the group primed with Ad and boosted with KV (P=0.01). Re-stimulation of all groups of mice with 0.5 μg of inactivated virus five months later resulted in a fast increase of antibody titers in all the groups tested. After virus stimulation, antibody titers in the groups that received KV alone or Ad prime-KV boost, were indistinguishable (P=0.800). Protection from challenge was similar (75%) in the groups of animals that received Ad prime-Hs boost or Ad prime-KV boost, or two doses of oil-adjuvanted KV. The data presented in this study suggest that sequential immunization with viral vectors-based vaccines combined with protein-based vaccines have the potential to enhance the quality of the immune response against FMDV. PMID:23683999

  19. Evaluation of the immune response elicited by vaccination with viral vectors encoding FMDV capsid proteins and boosted with inactivated virus.

    PubMed

    Romanutti, Carina; D'Antuono, Alejandra; Palacios, Carlos; Quattrocchi, Valeria; Zamorano, Patricia; La Torre, Jose; Mattion, Nora

    2013-08-30

    The aim of the present study was to assess the effect of introducing a priming step with replication-defective viral vectors encoding the capsid proteins of FMDV, followed by a boost with killed virus vaccines, using a suitable BALB/c mice model. Additionally, the immune response to other combined vector immunization regimens was studied. For this purpose, we analyzed different prime-boost immunizations with recombinant adenovirus (Ad), herpesvirus amplicons (Hs) and/or killed virus (KV) vaccines. The highest antibody titers were found in the group that received two doses of adjuvanted KV (P<0.002). Antibody titers were higher in those groups receiving a mixed regimen of vectors, compared to immunization with either vector alone (P<0.0001). Priming with any of the viral vectors induced a shift of the cytokine balance toward a Th1 type immune response regardless of the delivery system used for boosting. The highest IgG1 titer was induced by two doses of adjuvanted KV (P=0.0002) and the highest IgG2a titer corresponded to the group primed with Ad and boosted with KV (P=0.01). Re-stimulation of all groups of mice with 0.5 μg of inactivated virus five months later resulted in a fast increase of antibody titers in all the groups tested. After virus stimulation, antibody titers in the groups that received KV alone or Ad prime-KV boost, were indistinguishable (P=0.800). Protection from challenge was similar (75%) in the groups of animals that received Ad prime-Hs boost or Ad prime-KV boost, or two doses of oil-adjuvanted KV. The data presented in this study suggest that sequential immunization with viral vectors-based vaccines combined with protein-based vaccines have the potential to enhance the quality of the immune response against FMDV.

  20. The quest for conditional independence in prospectivity modeling: weights-of-evidence, boost weights-of-evidence, and logistic regression

    NASA Astrophysics Data System (ADS)

    Schaeben, Helmut; Semmler, Georg

    2016-09-01

    The objective of prospectivity modeling is prediction of the conditional probability of the presence T = 1 or absence T = 0 of a target T given favorable or prohibitive predictors B, or construction of a two classes 0,1 classification of T. A special case of logistic regression called weights-of-evidence (WofE) is geologists' favorite method of prospectivity modeling due to its apparent simplicity. However, the numerical simplicity is deceiving as it is implied by the severe mathematical modeling assumption of joint conditional independence of all predictors given the target. General weights of evidence are explicitly introduced which are as simple to estimate as conventional weights, i.e., by counting, but do not require conditional independence. Complementary to the regression view is the classification view on prospectivity modeling. Boosting is the construction of a strong classifier from a set of weak classifiers. From the regression point of view it is closely related to logistic regression. Boost weights-of-evidence (BoostWofE) was introduced into prospectivity modeling to counterbalance violations of the assumption of conditional independence even though relaxation of modeling assumptions with respect to weak classifiers was not the (initial) purpose of boosting. In the original publication of BoostWofE a fabricated dataset was used to "validate" this approach. Using the same fabricated dataset it is shown that BoostWofE cannot generally compensate lacking conditional independence whatever the consecutively processing order of predictors. Thus the alleged features of BoostWofE are disproved by way of counterexamples, while theoretical findings are confirmed that logistic regression including interaction terms can exactly compensate violations of joint conditional independence if the predictors are indicators.

  1. Boosting Belligerence

    PubMed Central

    Van de Vyver, Julie; Houston, Diane M.; Abrams, Dominic; Vasiljevic, Milica

    2016-01-01

    Major terrorist events, such as the recent attacks in Ankara, Sinai, and Paris, can have profound effects on a nation’s values, attitudes, and prejudices. Yet psychological evidence testing the impact of such events via data collected immediately before and after an attack is understandably rare. In the present research, we tested the independent and joint effects of threat (the July 7, 2005, London bombings) and political ideology on endorsement of moral foundations and prejudices among two nationally representative samples (combined N = 2,031) about 6 weeks before and 1 month after the London bombings. After the bombings, there was greater endorsement of the in-group foundation, lower endorsement of the fairness-reciprocity foundation, and stronger prejudices toward Muslims and immigrants. The differences in both the endorsement of the foundations and the prejudices were larger among people with a liberal orientation than among those with a conservative orientation. Furthermore, the changes in endorsement of moral foundations among liberals explained their increases in prejudice. The results highlight the value of psychological theory and research for understanding societal changes in attitudes and prejudices after major terrorist events. PMID:26674127

  2. An adaptive lidar

    NASA Astrophysics Data System (ADS)

    Oshlakov, V. G.; Andreev, M. I.; Malykh, D. D.

    2009-09-01

    Using the polarization characteristics of a target and its underlying surface one can change the target contrast range. As the target one can use the compact and discrete structures with different characteristics to reflect electromagnetic waves. An important problem, solved by the adaptive polarization lidar, is to determine the availability and identification of different targets based on their polarization characteristics against the background of underlying surface, which polarization characteristics are unknown. Another important problem of the adaptive polarization lidar is a search for the objects, which polarization characteristics are unknown, against the background of underlying surface, which polarization characteristics are known. The adaptive polarization lidar makes it possible to determine the presence of impurities in sea water. The characteristics of the adaptive polarization lidar undergo variations, i.e., polarization characteristics of a sensing signal and polarization characteristics of the receiver are varied depending on the problem to be solved. One of the versions of construction of the adaptive polarization lidar is considered. The increase of the contrast in the adaptive lidar has been demonstrated by the numerical experiment when sensing hydrosols on the background of the Rayleigh scattering, caused by clear water. The numerical experiment has also demonstrated the increase of the contrast in the adaptive lidar when sensing at two wavelengths of dry haze and dense haze on the background of the Rayleigh scattering, caused by the clear atmosphere. The most effective wavelength was chosen.

  3. [Adaptive optics for ophthalmology].

    PubMed

    Saleh, M

    2016-04-01

    Adaptive optics is a technology enhancing the visual performance of an optical system by correcting its optical aberrations. Adaptive optics have already enabled several breakthroughs in the field of visual sciences, such as improvement of visual acuity in normal and diseased eyes beyond physiologic limits, and the correction of presbyopia. Adaptive optics technology also provides high-resolution, in vivo imaging of the retina that may eventually help to detect the onset of retinal conditions at an early stage and provide better assessment of treatment efficacy.

  4. Adaptive network countermeasures.

    SciTech Connect

    McClelland-Bane, Randy; Van Randwyk, Jamie A.; Carathimas, Anthony G.; Thomas, Eric D.

    2003-10-01

    This report describes the results of a two-year LDRD funded by the Differentiating Technologies investment area. The project investigated the use of countermeasures in protecting computer networks as well as how current countermeasures could be changed in order to adapt with both evolving networks and evolving attackers. The work involved collaboration between Sandia employees and students in the Sandia - California Center for Cyber Defenders (CCD) program. We include an explanation of the need for adaptive countermeasures, a description of the architecture we designed to provide adaptive countermeasures, and evaluations of the system.

  5. Improving performance of natural language processing part-of-speech tagging on clinical narratives through domain adaptation

    PubMed Central

    Ferraro, Jeffrey P; Daumé, Hal; DuVall, Scott L; Chapman, Wendy W; Harkema, Henk; Haug, Peter J

    2013-01-01

    Objective Natural language processing (NLP) tasks are commonly decomposed into subtasks, chained together to form processing pipelines. The residual error produced in these subtasks propagates, adversely affecting the end objectives. Limited availability of annotated clinical data remains a barrier to reaching state-of-the-art operating characteristics using statistically based NLP tools in the clinical domain. Here we explore the unique linguistic constructions of clinical texts and demonstrate the loss in operating characteristics when out-of-the-box part-of-speech (POS) tagging tools are applied to the clinical domain. We test a domain adaptation approach integrating a novel lexical-generation probability rule used in a transformation-based learner to boost POS performance on clinical narratives. Methods Two target corpora from independent healthcare institutions were constructed from high frequency clinical narratives. Four leading POS taggers with their out-of-the-box models trained from general English and biomedical abstracts were evaluated against these clinical corpora. A high performing domain adaptation method, Easy Adapt, was compared to our newly proposed method ClinAdapt. Results The evaluated POS taggers drop in accuracy by 8.5–15% when tested on clinical narratives. The highest performing tagger reports an accuracy of 88.6%. Domain adaptation with Easy Adapt reports accuracies of 88.3–91.0% on clinical texts. ClinAdapt reports 93.2–93.9%. Conclusions ClinAdapt successfully boosts POS tagging performance through domain adaptation requiring a modest amount of annotated clinical data. Improving the performance of critical NLP subtasks is expected to reduce pipeline error propagation leading to better overall results on complex processing tasks. PMID:23486109

  6. Simulating relativistic beam and plasma systems using an optimal boosted frame

    SciTech Connect

    Vay, J.-L.; Bruhwiler, D. L.; Geddes, C. G. R.; Fawley, W. M.; Martins, S. F.; Cary, J. R.; Cormier-Michel, E.; Cowan, B.; Fonseca, R. A.; Furman, M. A.; Lu, W.; Mori, W. B.; Silva, L. O.

    2009-05-01

    It was shown recently that it may be computationally advantageous to perform computer simulations in a Lorentz boosted frame for a certain class of systems. However, even if the computer model relies on a covariant set of equations, it was pointed out that algorithmic difficulties related to discretization errors may have to be overcome in order to take full advantage of the potential speedup. In this paper, we summarize the findings, the difficulties and their solutions, and review the applications of the technique that have been performed to date.

  7. Particle tower technology applied to metallurgic plants and peak-time boosting of steam power plants

    NASA Astrophysics Data System (ADS)

    Amsbeck, Lars; Buck, Reiner; Prosin, Tobias

    2016-05-01

    Using solar tower technology with ceramic particles as heat transfer and storage medium to preheat scrap for induction furnaces in foundries provides solar generated heat to save electricity. With such a system an unsubsidized payback time of only 4 years is achieved for a 70000t/a foundry in Brazil. The same system can be also used for heat treatment of metals. If electricity is used to heat inert atmospheres a favorable economic performance is also achievable for the particle system. The storage in a particle system enables solar boosting to be restricted to only peak times, enabling an interesting business case opportunity.

  8. Clinical development of intramuscular electroporation: providing a "boost" for DNA vaccines.

    PubMed

    Khan, Amir S; Broderick, Kate E; Sardesai, Niranjan Y

    2014-01-01

    The development of effective vaccines has helped to eradicate or control the spread of numerous infectious diseases. However, there are many more diseases that have proved more difficult to eliminate using conventional vaccines. The recent innovation of DNA vaccines may provide a "boost" to the development efforts. While the early efforts of DNA vaccines in the clinic were disappointing, the use of in vivo electroporation has helped to provide some basis for optimism. Now, there are several ongoing clinical studies of vaccines against such diseases as malaria, HIV, hepatitis C, and even various types of cancer. This review will highlight three recently published clinical studies using intramuscular DNA administration with electroporation.

  9. Lightlike limit of the boosted Kerr black holes in higher-dimensional spacetimes

    NASA Astrophysics Data System (ADS)

    Yoshino, Hirotaka

    2005-02-01

    Deriving the gravitational field of the high-energy objects is an important theme because the black holes might be produced in particle collisions in the brane world scenario. In this paper, we develop a method for boosting the metric of the stationary objects and taking the lightlike limit in higher-dimensional spacetimes, using the Kerr black hole as one example. We analytically construct the metric of lightlike Kerr black holes and find that this method contains no ambiguity in contrast to the four-dimensional case. We discuss the possible implications of our results in the brane world context.

  10. Fractionated stereotactic radiotherapy boost for gynecologic tumors: An alternative to brachytherapy?

    SciTech Connect

    Molla, Meritxell; Escude, Lluis D.; Nouet, Philippe; Popowski, Youri D.Sc.; Hidalgo, Alberto; Rouzaud, Michel; Linero, Dolores; Miralbell, Raymond . E-mail: Raymond.Miralbell@hcuge.ch

    2005-05-01

    Purpose: A brachytherapy (BT) boost to the vaginal vault is considered standard treatment for many endometrial or cervical cancers. We aimed to challenge this treatment standard by using stereotactic radiotherapy (SRT) with a linac-based micromultileaf collimator technique. Methods and Materials: Since January 2002, 16 patients with either endometrial (9) or cervical (7) cancer have been treated with a final boost to the areas at higher risk for relapse. In 14 patients, the target volume included the vaginal vault, the upper vagina, the parametria, or (if not operated) the uterus (clinical target volume [CTV]). In 2 patients with local relapse, the CTV was the tumor in the vaginal stump. Margins of 6-10 mm were added to the CTV to define the planning target volume (PTV). Hypofractionated dynamic-arc or intensity-modulated radiotherapy techniques were used. Postoperative treatment was delivered in 12 patients (2 x 7 Gy to the PTV with a 4-7-day interval between fractions). In the 4 nonoperated patients, a dose of 4 Gy/fraction in 5 fractions with 2 to 3 days' interval was delivered. Patients were immobilized in a customized vacuum body cast and optimally repositioned with an infrared-guided system developed for extracranial SRT. To further optimize daily repositioning and target immobilization, an inflated rectal balloon was used during each treatment fraction. In 10 patients, CT resimulation was performed before the last boost fraction to assess for repositioning reproducibility via CT-to-CT registration and to estimate PTV safety margins around the CTV. Finally, a comparative treatment planning study between BT and SRT was performed in 2 patients with an operated endometrial Stage I cancer. Results: No patient developed severe acute urinary or low-intestinal toxicity. No patient developed urinary late effects (>6 months). One patient with a vaginal relapse previously irradiated to the pelvic region presented with Grade 3 rectal bleeding 18 months after retreatment

  11. A low-voltage boost converter using a forward converter with integrated Meissner oscillator

    NASA Astrophysics Data System (ADS)

    Woias, P.; Islam, M.; Heller, S.; Roth, R.

    2013-12-01

    This paper describes a novel boost converter to be used with energy harvesters that provide only low output voltages. The device is self-supplied from electric power delivered to its input. With peak power conversion efficiencies above 30% at start-up voltages down to 10 mV this circuit sets best values in comparison with the state-of-the-art. This is achieved by the novel combination of a Meissner oscillator, used as stand-alone in most low-voltage step-up converters today, with a forward converter usually applied in high power systems.

  12. Learning a structured graphical model with boosted top-down features for ultrasound image segmentation.

    PubMed

    Hao, Zhihui; Wang, Qiang; Wang, Xiaotao; Kim, Jung Bae; Hwang, Youngkyoo; Cho, Baek Hwan; Guo, Ping; Lee, Won Ki

    2013-01-01

    A key problem for many medical image segmentation tasks is the combination of different-level knowledge. We propose a novel scheme of embedding detected regions into a superpixel based graphical model, by which we achieve a full leverage on various image cues for ultrasound lesion segmentation. Region features are mapped into a higher-dimensional space via a boosted model to become well controlled. Parameters for regions, superpixels and a new affinity term are learned simultaneously within the framework of structured learning. Experiments on a breast ultrasound image data set confirm the effectiveness of the proposed approach as well as our two novel modules.

  13. Results of TC-1 boost pump icing tests in the space power facility

    NASA Technical Reports Server (NTRS)

    Gentile, L. C.; Walter, R. J.

    1975-01-01

    A series of tests were conducted in the space power facility to investigate the failure of the Centaur oxidizer boost pump during the Titan/Centaur proof flight February 11, 1974. The three basic objectives of the tests were: (1) demonstrate if an evaporative freezing type failure mechanism could have prevented the pump from operating, (2) determine if steam from the exhaust of one of the attitude control engine could have entered a pump seal cavity and caused the failure, and (3) obtain data on the heating effects of the exhaust plume from a hydrogen peroxide attitude control engine.

  14. Physics of a ballistic missile defense - The chemical laser boost-phase defense

    NASA Technical Reports Server (NTRS)

    Grabbe, Crockett L.

    1988-01-01

    The basic physics involved in proposals to use a chemical laser based on satellites for a boost-phase defense are investigated. After a brief consideration of simple physical conditions for the defense, a calculation of an equation for the number of satellites needed for the defense is made along with some typical values of this for possible future conditions for the defense. Basic energy and power requirements for the defense are determined. A sumary is made of probable minimum conditions that must be achieved for laser power, targeting accuracy, number of satellites, and total sources for power needed.

  15. A novel boost circuit design and in situ electricity application for elemental sulfur recovery

    NASA Astrophysics Data System (ADS)

    Liu, Jia; Feng, Yujie; He, Weihua; Gong, Yuanyuan; Qu, Youpeng; Ren, Nanqi

    2014-02-01

    A novel system containing a microbial electrochemical system (MES) for electricity generation and sulfate conversion, a novel boost circuit (NBC) for in situ utilization of the electrical energy and an electrochemical deposition cell (ECD) to recover sulfur in water is designed and established. This combined system has a higher energy utilization efficiency of 63.6% than that of conventional sulfate reduction reactors with an elemental sulfur recovery efficiency up to 46.5 ± 1.5% without net energy input. This system offers a promising, and cost-effective approach for sulfate wastewater treatment.

  16. Varicella-zoster virus vaccination under the exogenous boosting hypothesis: two ethical perspectives.

    PubMed

    Luyten, Jeroen; Ogunjimi, Benson; Beutels, Philippe

    2014-12-12

    The varicella-zoster virus (VZV) causes two diseases: varicella ('chickenpox') and herpes zoster ('shingles'). VZV vaccination of children reduces exposure to chickenpox in the population and it has been hypothesized that this could increase the prevalence of shingles. This 'exogenous boosting' effect of VZV raises an important equity concern: introducing a vaccination program could advance the health of one population group (children) at the expense of another (adults and elderly). We discuss the program's justifiability from two ethical perspectives, classic utilitarianism and contractualism. Whereas the former framework might offer a foundation for the case against introducing this vaccination, the latter offers a basis to justify it.

  17. High-Dose Split-Course Radiation Therapy for Anal Cancer: Outcome Analysis Regarding the Boost Strategy (CORS-03 Study)

    SciTech Connect

    Hannoun-Levi, Jean-Michel; Ortholan, Cecile; Resbeut, Michel; Teissier, Eric; Ronchin, Philippe; Cowen, Didier; Zaccariotto, Audrey; Benezery, Karen; Francois, Eric; Salem, Naji; Ellis, Steve; Azria, David; Gerard, Jean-Pierre

    2011-07-01

    Purpose: To retrospectively assess the clinical outcome in anal cancer patients treated with split-course radiation therapy and boosted through external-beam radiation therapy (EBRT) or brachytherapy (BCT). Methods and Materials: From January 2000 to December 2004, a selected group (162 patients) with invasive nonmetastatic anal squamous cell carcinoma was studied. Tumor staging reported was T1 = 31 patients (19%), T2 = 77 patients (48%), T3 = 42 patients (26%), and T4= 12 patients (7%). Lymph node status was N0-1 (86%) and N2-3 (14%). Patients underwent a first course of EBRT: mean dose 45.1 Gy (range, 39.5-50) followed by a boost: mean dose 17.9 Gy (range, 8-25) using EBRT (76 patients, 47%) or BCT (86 patients, 53%). All characteristics of patients and tumors were well balanced between the BCT and EBRT groups. Results: The mean overall treatment time (OTT) was 82 days (range, 45-143) and 67 days (range, 37-128) for the EBRT and BCT groups, respectively (p < 0.001). The median follow-up was 62 months (range, 2-108). The 5-year cumulative rate of local recurrence (CRLR) was 21%. In the univariate analysis, the prognostic factors for CRLR were as follows: T stage (T1-2 = 15% vs. T3-4 = 36%, p = 0.03), boost technique (BCT = 12% vs. EBRT = 33%, p = 0.002) and OTT (OTT <80 days = 14%, OTT {>=}80 days = 34%, p = 0.005). In the multivariate analysis, BCT boost was the unique prognostic factor (hazard ratio = 0.62 (0.41-0.92). In the subgroup of patients with OTT <80 days, the 5-year CRLR was significantly increased with the BCT boost (BC = 9% vs. EBRT = 28%, p = 0.03). In the case of OTT {>=}80 days, the 5-year CRLR was not affected by the boost technique (BCT = 29% vs. EBRT = 38%, p = 0.21). Conclusion: In anal cancer, when OTT is <80 days, BCT boost is superior to EBRT boost for CRLR. These results suggest investigating the benefit of BCT boost in prospective trials.

  18. Whole genome sequencing of turbot (Scophthalmus maximus; Pleuronectiformes): a fish adapted to demersal life.

    PubMed

    Figueras, Antonio; Robledo, Diego; Corvelo, André; Hermida, Miguel; Pereiro, Patricia; Rubiolo, Juan A; Gómez-Garrido, Jèssica; Carreté, Laia; Bello, Xabier; Gut, Marta; Gut, Ivo Glynne; Marcet-Houben, Marina; Forn-Cuní, Gabriel; Galán, Beatriz; García, José Luis; Abal-Fabeiro, José Luis; Pardo, Belen G; Taboada, Xoana; Fernández, Carlos; Vlasova, Anna; Hermoso-Pulido, Antonio; Guigó, Roderic; Álvarez-Dios, José Antonio; Gómez-Tato, Antonio; Viñas, Ana; Maside, Xulio; Gabaldón, Toni; Novoa, Beatriz; Bouza, Carmen; Alioto, Tyler; Martínez, Paulino

    2016-06-01

    The turbot is a flatfish (Pleuronectiformes) with increasing commercial value, which has prompted active genomic research aimed at more efficient selection. Here we present the sequence and annotation of the turbot genome, which represents a milestone for both boosting breeding programmes and ascertaining the origin and diversification of flatfish. We compare the turbot genome with model fish genomes to investigate teleost chromosome evolution. We observe a conserved macrosyntenic pattern within Percomorpha and identify large syntenic blocks within the turbot genome related to the teleost genome duplication. We identify gene family expansions and positive selection of genes associated with vision and metabolism of membrane lipids, which suggests adaptation to demersal lifestyle and to cold temperatures, respectively. Our data indicate a quick evolution and diversification of flatfish to adapt to benthic life and provide clues for understanding their controversial origin. Moreover, we investigate the genomic architecture of growth, sex determination and disease resistance, key traits for understanding local adaptation and boosting turbot production, by mapping candidate genes and previously reported quantitative trait loci. The genomic architecture of these productive traits has allowed the identification of candidate genes and enriched pathways that may represent useful information for future marker-assisted selection in turbot.

  19. Whole genome sequencing of turbot (Scophthalmus maximus; Pleuronectiformes): a fish adapted to demersal life

    PubMed Central

    Figueras, Antonio; Robledo, Diego; Corvelo, André; Hermida, Miguel; Pereiro, Patricia; Rubiolo, Juan A.; Gómez-Garrido, Jèssica; Carreté, Laia; Bello, Xabier; Gut, Marta; Gut, Ivo Glynne; Marcet-Houben, Marina; Forn-Cuní, Gabriel; Galán, Beatriz; García, José Luis; Abal-Fabeiro, José Luis; Pardo, Belen G.; Taboada, Xoana; Fernández, Carlos; Vlasova, Anna; Hermoso-Pulido, Antonio; Guigó, Roderic; Álvarez-Dios, José Antonio; Gómez-Tato, Antonio; Viñas, Ana; Maside, Xulio; Gabaldón, Toni; Novoa, Beatriz; Bouza, Carmen; Alioto, Tyler; Martínez, Paulino

    2016-01-01

    The turbot is a flatfish (Pleuronectiformes) with increasing commercial value, which has prompted active genomic research aimed at more efficient selection. Here we present the sequence and annotation of the turbot genome, which represents a milestone for both boosting breeding programmes and ascertaining the origin and diversification of flatfish. We compare the turbot genome with model fish genomes to investigate teleost chromosome evolution. We observe a conserved macrosyntenic pattern within Percomorpha and identify large syntenic blocks within the turbot genome related to the teleost genome duplication. We identify gene family expansions and positive selection of genes associated with vision and metabolism of membrane lipids, which suggests adaptation to demersal lifestyle and to cold temperatures, respectively. Our data indicate a quick evolution and diversification of flatfish to adapt to benthic life and provide clues for understanding their controversial origin. Moreover, we investigate the genomic architecture of growth, sex determination and disease resistance, key traits for understanding local adaptation and boosting turbot production, by mapping candidate genes and previously reported quantitative trait loci. The genomic architecture of these productive traits has allowed the identification of candidate genes and enriched pathways that may represent useful information for future marker-assisted selection in turbot. PMID:26951068

  20. Whole genome sequencing of turbot (Scophthalmus maximus; Pleuronectiformes): a fish adapted to demersal life.

    PubMed

    Figueras, Antonio; Robledo, Diego; Corvelo, André; Hermida, Miguel; Pereiro, Patricia; Rubiolo, Juan A; Gómez-Garrido, Jèssica; Carreté, Laia; Bello, Xabier; Gut, Marta; Gut, Ivo Glynne; Marcet-Houben, Marina; Forn-Cuní, Gabriel; Galán, Beatriz; García, José Luis; Abal-Fabeiro, José Luis; Pardo, Belen G; Taboada, Xoana; Fernández, Carlos; Vlasova, Anna; Hermoso-Pulido, Antonio; Guigó, Roderic; Álvarez-Dios, José Antonio; Gómez-Tato, Antonio; Viñas, Ana; Maside, Xulio; Gabaldón, Toni; Novoa, Beatriz; Bouza, Carmen; Alioto, Tyler; Martínez, Paulino

    2016-06-01

    The turbot is a flatfish (Pleuronectiformes) with increasing commercial value, which has prompted active genomic research aimed at more efficient selection. Here we present the sequence and annotation of the turbot genome, which represents a milestone for both boosting breeding programmes and ascertaining the origin and diversification of flatfish. We compare the turbot genome with model fish genomes to investigate teleost chromosome evolution. We observe a conserved macrosyntenic pattern within Percomorpha and identify large syntenic blocks within the turbot genome related to the teleost genome duplication. We identify gene family expansions and positive selection of genes associated with vision and metabolism of membrane lipids, which suggests adaptation to demersal lifestyle and to cold temperatures, respectively. Our data indicate a quick evolution and diversification of flatfish to adapt to benthic life and provide clues for understanding their controversial origin. Moreover, we investigate the genomic architecture of growth, sex determination and disease resistance, key traits for understanding local adaptation and boosting turbot production, by mapping candidate genes and previously reported quantitative trait loci. The genomic architecture of these productive traits has allowed the identification of candidate genes and enriched pathways that may represent useful information for future marker-assisted selection in turbot. PMID:26951068

  1. Adaptive Heat Engine.

    PubMed

    Allahverdyan, A E; Babajanyan, S G; Martirosyan, N H; Melkikh, A V

    2016-07-15

    A major limitation of many heat engines is that their functioning demands on-line control and/or an external fitting between the environmental parameters (e.g., temperatures of thermal baths) and internal parameters of the engine. We study a model for an adaptive heat engine, where-due to feedback from the functional part-the engine's structure adapts to given thermal baths. Hence, no on-line control and no external fitting are needed. The engine can employ unknown resources; it can also adapt to results of its own functioning that make the bath temperatures closer. We determine resources of adaptation and relate them to the prior information available about the environment.

  2. Adaptive Heat Engine.

    PubMed

    Allahverdyan, A E; Babajanyan, S G; Martirosyan, N H; Melkikh, A V

    2016-07-15

    A major limitation of many heat engines is that their functioning demands on-line control and/or an external fitting between the environmental parameters (e.g., temperatures of thermal baths) and internal parameters of the engine. We study a model for an adaptive heat engine, where-due to feedback from the functional part-the engine's structure adapts to given thermal baths. Hence, no on-line control and no external fitting are needed. The engine can employ unknown resources; it can also adapt to results of its own functioning that make the bath temperatures closer. We determine resources of adaptation and relate them to the prior information available about the environment. PMID:27472104

  3. Adaptations, exaptations, and spandrels.

    PubMed

    Buss, D M; Haselton, M G; Shackelford, T K; Bleske, A L; Wakefield, J C

    1998-05-01

    Adaptation and natural selection are central concepts in the emerging science of evolutionary psychology. Natural selection is the only known causal process capable of producing complex functional organic mechanisms. These adaptations, along with their incidental by-products and a residue of noise, comprise all forms of life. Recently, S. J. Gould (1991) proposed that exaptations and spandrels may be more important than adaptations for evolutionary psychology. These refer to features that did not originally arise for their current use but rather were co-opted for new purposes. He suggested that many important phenomena--such as art, language, commerce, and war--although evolutionary in origin, are incidental spandrels of the large human brain. The authors outline the conceptual and evidentiary standards that apply to adaptations, exaptations, and spandrels and discuss the relative utility of these concepts for psychological science. PMID:9612136

  4. Rocketing into Adaptive Inquiry.

    ERIC Educational Resources Information Center

    Farenga, Stephen J.; Joyce, Beverly A.; Dowling, Thomas W.

    2002-01-01

    Defines adaptive inquiry and argues for employing this method which allows lessons to be shaped in response to student needs. Illustrates this idea by detailing an activity in which teams of students build rockets. (DDR)

  5. Adaptive Management of Ecosystems

    EPA Science Inventory

    Adaptive management is an approach to natural resource management that emphasizes learning through management. As such, management may be treated as experiment, with replication, or management may be conducted in an iterative manner. Although the concept has resonated with many...

  6. The genomics of adaptation.

    PubMed

    Radwan, Jacek; Babik, Wiesław

    2012-12-22

    The amount and nature of genetic variation available to natural selection affect the rate, course and outcome of evolution. Consequently, the study of the genetic basis of adaptive evolutionary change has occupied biologists for decades, but progress has been hampered by the lack of resolution and the absence of a genome-level perspective. Technological advances in recent years should now allow us to answer many long-standing questions about the nature of adaptation. The data gathered so far are beginning to challenge some widespread views of the way in which natural selection operates at the genomic level. Papers in this Special Feature of Proceedings of the Royal Society B illustrate various aspects of the broad field of adaptation genomics. This introductory article sets up a context and, on the basis of a few selected examples, discusses how genomic data can advance our understanding of the process of adaptation.

  7. Adaptive Heat Engine

    NASA Astrophysics Data System (ADS)

    Allahverdyan, A. E.; Babajanyan, S. G.; Martirosyan, N. H.; Melkikh, A. V.

    2016-07-01

    A major limitation of many heat engines is that their functioning demands on-line control and/or an external fitting between the environmental parameters (e.g., temperatures of thermal baths) and internal parameters of the engine. We study a model for an adaptive heat engine, where—due to feedback from the functional part—the engine's structure adapts to given thermal baths. Hence, no on-line control and no external fitting are needed. The engine can employ unknown resources; it can also adapt to results of its own functioning that make the bath temperatures closer. We determine resources of adaptation and relate them to the prior information available about the environment.

  8. Islands, resettlement and adaptation

    NASA Astrophysics Data System (ADS)

    Barnett, Jon; O'Neill, Saffron J.

    2012-01-01

    Resettlement of people living on islands in anticipation of climate impacts risks maladaptation, but some forms of population movement carry fewer risks and larger rewards in terms of adapting to climate change.

  9. Dissociation as complex adaptation.

    PubMed

    Sel, R

    1997-03-01

    In this article the general theory of complex adaptive systems, substantiated by non-linear dynamics, will be used to put the dissociative disorders into a theoretical framework and clarify their genesis and presentation. When a system is far out of equilibrium, dissipative structures may be formed ('order out of chaos', as Prigogine (1) has put it). These structures provide the starting point for further evolution and co-evolution of competing groups of functional schemata divided on a bifurcation surface. Complex adaptation is almost inevitable in a complicated system (such as the brain) driven by non-linear dynamics. Dissociation is thus regarded as a consequence of adaptation to a chaotic environment rich in contrasts. In a sufficiently complex environment a person with dissociative identity disorder is more adapted and thus more likely to occur than a 'normal' monopersonality individual.

  10. Boosting BCG with inert spores improves immunogenicity and induces specific IL-17 responses in a murine model of bovine tuberculosis.

    PubMed

    Garcia-Pelayo, M Carmen; Kaveh, Daryan A; Sibly, Laura; Webb, Paul R; Bull, Naomi C; Cutting, Simon M; Hogarth, Philip J

    2016-05-01

    Tuberculosis (TB) remains a global pandemic, in both animals and man, and novel vaccines are urgently required. Heterologous prime-boost of BCG represents a promising strategy for improved TB vaccines, with respiratory delivery the most efficacious to date. Such an approach may be an ideal vaccination strategy against bovine TB (bTB), but respiratory vaccination presents a technical challenge in cattle. Inert bacterial spores represent an attractive vaccine vehicle. Therefore we evaluated whether parenterally administered spores are efficacious when used as a BCG boost in a murine model of immunity against Mycobacterium bovis. Here we report the use of heat-killed, TB10.4 adsorbed, Bacillus subtilis spores delivered via subcutaneous injection to boost immunity primed by BCG. We demonstrate that this approach improves the immunogenicity of BCG. Interestingly, this associated with substantial boosting of IL-17 responses; considered to be important in protective immunity against TB. These data demonstrate that parenteral delivery of spores represents a promising vaccine vehicle for boosting BCG, and identifies potential for optimisation for use as a vaccine for bovine TB.

  11. DNA vaccine prime and recombinant FPV vaccine boost: an important candidate immunization strategy to control bluetongue virus type 1.

    PubMed

    Li, Junping; Yang, Tao; Xu, Qingyuan; Sun, Encheng; Feng, Yufei; Lv, Shuang; Zhang, Qin; Wang, Haixiu; Wu, Donglai

    2015-10-01

    Bluetongue virus (BTV) is the causative agent of bluetongue (BT), an important sheep disease that caused great economic loss to the sheep industry. There are 26 BTV serotypes based on the outer protein VP2. However, the serotypes BTV-1 and BTV-16 are the two most prevalent serotypes in China. Vaccination is the most effective method of preventing viral infections. Therefore, the need for an effective vaccine against BTV is urgent. In this study, DNA vaccines and recombinant fowlpox virus (rFPV) vaccines expressing VP2 alone or VP2 in combination with VP5 or co-expressing the VP2 and VP5 proteins of BTV-1 were evaluated in both mice and sheep. Several strategies were tested in mice, including DNA vaccine prime and boost, rFPV vaccine prime and boost, and DNA vaccine prime and rFPV vaccine boost. We then determined the best vaccine strategy in sheep. Our results indicated that a strategy combining a DNA vaccine prime (co-expressing VP2 and VP5) followed by an rFPV vaccine boost (co-expressing VP2 and VP5) induced a high titer of neutralizing antibodies in sheep. Therefore, our data suggest that a DNA vaccine consisting of a pCAG-(VP2+VP5) prime and an rFPV-(VP2+VP5) boost is an important candidate for the design of a novel vaccine against BTV-1.

  12. Adaptable DC offset correction

    NASA Technical Reports Server (NTRS)

    Golusky, John M. (Inventor); Muldoon, Kelly P. (Inventor)

    2009-01-01

    Methods and systems for adaptable DC offset correction are provided. An exemplary adaptable DC offset correction system evaluates an incoming baseband signal to determine an appropriate DC offset removal scheme; removes a DC offset from the incoming baseband signal based on the appropriate DC offset scheme in response to the evaluated incoming baseband signal; and outputs a reduced DC baseband signal in response to the DC offset removed from the incoming baseband signal.

  13. The effects of working memory resource depletion and training on sensorimotor adaptation.

    PubMed

    Anguera, Joaquin A; Bernard, Jessica A; Jaeggi, Susanne M; Buschkuehl, Martin; Benson, Bryan L; Jennett, Sarah; Humfleet, Jennifer; Reuter-Lorenz, Patricia A; Jonides, John; Seidler, Rachael D

    2012-03-01

    We have recently demonstrated that visuospatial working memory performance predicts the rate of motor skill learning, particularly during the early phase of visuomotor adaptation. Here, we follow up these correlational findings with direct manipulations of working memory resources to determine the impact on visuomotor adaptation, a form of motor learning. We conducted two separate experiments. In the first one, we used a resource depletion strategy to investigate whether the rate of early visuomotor adaptation would be negatively affected by fatigue of spatial working memory resources. In the second study, we employed a dual n-back task training paradigm that has been shown to result in transfer effects [1] over five weeks to determine whether training-related improvements would boost the rate of early visuomotor adaptation. The depletion of spatial working memory resources negatively affected the rate of early visuomotor adaptation. However, enhancing working memory capacity via training did not lead to improved rates of visuomotor adaptation, suggesting that working memory capacity may not be the factor limiting maximal rate of visuomotor adaptation in young adults. These findings are discussed from a resource limitation/capacity framework with respect to current views of motor learning. PMID:22155489

  14. The effects of working memory resource depletion and training on sensorimotor adaptation

    PubMed Central

    Anguera, Joaquin A.; Bernard, Jessica A.; Jaeggi, Susanne M.; Buschkuehl, Martin; Benson, Bryan L.; Jennett, Sarah; Humfleet, Jennifer; Reuter-Lorenz, Patricia; Jonides, John; Seidler, Rachael D.

    2011-01-01

    We have recently demonstrated that visuospatial working memory performance predicts the rate of motor skill learning, particularly during the early phase of visuomotor adaptation. Here, we follow up these correlational findings with direct manipulations of working memory resources to determine the impact on visuomotor adaptation, a form of motor learning. We conducted two separate experiments. In the first one, we used a resource depletion strategy to investigate whether the rate of early visuomotor adaptation would be negatively affected by fatigue of spatial working memory resources. In the second study, we employed a dual n-back task training paradigm that has been shown to result in transfer effects [1] over five weeks to determine whether training-related improvements would boost the rate of early visuomotor adaptation. The depletion of spatial working memory resources negatively affected the rate of early visuomotor adaptation. However, enhancing working memory capacity via training did not lead to improved rates of visuomotor adaptation, suggesting that working memory capacity may not be the factor limiting maximal rate of visuomotor adaptation in young adults. These findings are discussed from a resource limitation / capacity framework with respect to current views of motor learning. PMID:22155489

  15. Leak test adapter for containers

    DOEpatents

    Hallett, Brian H.; Hartley, Michael S.

    1996-01-01

    An adapter is provided for facilitating the charging of containers and leak testing penetration areas. The adapter comprises an adapter body and stem which are secured to the container's penetration areas. The container is then pressurized with a tracer gas. Manipulating the adapter stem installs a penetration plug allowing the adapter to be removed and the penetration to be leak tested with a mass spectrometer. Additionally, a method is provided for using the adapter.

  16. Adaptation and perceptual norms

    NASA Astrophysics Data System (ADS)

    Webster, Michael A.; Yasuda, Maiko; Haber, Sara; Leonard, Deanne; Ballardini, Nicole

    2007-02-01

    We used adaptation to examine the relationship between perceptual norms--the stimuli observers describe as psychologically neutral, and response norms--the stimulus levels that leave visual sensitivity in a neutral or balanced state. Adapting to stimuli on opposite sides of a neutral point (e.g. redder or greener than white) biases appearance in opposite ways. Thus the adapting stimulus can be titrated to find the unique adapting level that does not bias appearance. We compared these response norms to subjectively defined neutral points both within the same observer (at different retinal eccentricities) and between observers. These comparisons were made for visual judgments of color, image focus, and human faces, stimuli that are very different and may depend on very different levels of processing, yet which share the property that for each there is a well defined and perceptually salient norm. In each case the adaptation aftereffects were consistent with an underlying sensitivity basis for the perceptual norm. Specifically, response norms were similar to and thus covaried with the perceptual norm, and under common adaptation differences between subjectively defined norms were reduced. These results are consistent with models of norm-based codes and suggest that these codes underlie an important link between visual coding and visual experience.

  17. Adaptation through proportion

    NASA Astrophysics Data System (ADS)

    Xiong, Liyang; Shi, Wenjia; Tang, Chao

    2016-08-01

    Adaptation is a ubiquitous feature in biological sensory and signaling networks. It has been suggested that adaptive systems may follow certain simple design principles across diverse organisms, cells and pathways. One class of networks that can achieve adaptation utilizes an incoherent feedforward control, in which two parallel signaling branches exert opposite but proportional effects on the output at steady state. In this paper, we generalize this adaptation mechanism by establishing a steady-state proportionality relationship among a subset of nodes in a network. Adaptation can be achieved by using any two nodes in the sub-network to respectively regulate the output node positively and negatively. We focus on enzyme networks and first identify basic regulation motifs consisting of two and three nodes that can be used to build small networks with proportional relationships. Larger proportional networks can then be constructed modularly similar to LEGOs. Our method provides a general framework to construct and analyze a class of proportional and/or adaptation networks with arbitrary size, flexibility and versatile functional features.

  18. The Climate Adaptation Frontier

    SciTech Connect

    Preston, Benjamin L

    2013-01-01

    Climate adaptation has emerged as a mainstream risk management strategy for assisting in maintaining socio-ecological systems within the boundaries of a safe operating space. Yet, there are limits to the ability of systems to adapt. Here, we introduce the concept of an adaptation frontier , which is defined as a socio-ecological system s transitional adaptive operating space between safe and unsafe domains. A number of driving forces are responsible for determining the sustainability of systems on the frontier. These include path dependence, adaptation/development deficits, values conflicts and discounting of future loss and damage. The cumulative implications of these driving forces are highly uncertain. Nevertheless, the fact that a broad range of systems already persist at the edge of their frontiers suggests a high likelihood that some limits will eventually be exceeded. The resulting system transformation is likely to manifest as anticipatory modification of management objectives or loss and damage. These outcomes vary significantly with respect to their ethical implications. Successful navigation of the adaptation frontier will necessitate new paradigms of risk governance to elicit knowledge that encourages reflexive reevaluation of societal values that enable or constrain sustainability.

  19. Whole breast and excision cavity radiotherapy plan comparison: Conformal radiotherapy with sequential boost versus intensity-modulated radiation therapy with a simultaneously integrated boost

    SciTech Connect

    Small, Katherine; Kelly, Chris; Beldham-Collins, Rachael; Gebski, Val

    2013-03-15

    A comparative study was conducted comparing the difference between (1) conformal radiotherapy (CRT) to the whole breast with sequential boost excision cavity plans and (2) intensity-modulated radiation therapy (IMRT) to the whole breast with simultaneously integrated boost to the excision cavity. The computed tomography (CT) data sets of 25 breast cancer patients were used and the results analysed to determine if either planning method produced superior plans. CT data sets from 25 past breast cancer patients were planned using (1) CRT prescribed to 50 Gy in 25 fractions (Fx) to the whole-breast planning target volume (PTV) and 10 Gy in 5Fx to the excision cavity and (2) IMRT prescribed to 60 Gy in 25Fx, with 60 Gy delivered to the excision cavity PTV and 50 Gy delivered to the whole-breast PTV, treated simultaneously. In total, 50 plans were created, with each plan evaluated by PTV coverage using conformity indices, plan maximum dose, lung dose, and heart maximum dose for patients with left-side lesions. CRT plans delivered the lowest plan maximum doses in 56% of cases (average CRT = 6314.34 cGy, IMRT = 6371.52 cGy). They also delivered the lowest mean lung dose in 68% of cases (average CRT = 1206.64 cGy, IMRT = 1288.37 cGy) and V20 in 88% of cases (average CRT = 20.03%, IMRT = 21.73%) and V30 doses in 92% of cases (average CRT = 16.82%, IMRT = 17.97%). IMRT created more conformal plans, using both conformity index and conformation number, in every instance, and lower heart maximum doses in 78.6% of cases (average CRT = 5295.26 cGy, IMRT = 5209.87 cGy). IMRT plans produced superior dose conformity and shorter treatment duration, but a slightly higher planning maximum and increased lung doses. IMRT plans are also faster to treat on a daily basis, with shorter fractionation.

  20. Boosting framework for mammographic mass classification with combination of CC and MLO view information

    NASA Astrophysics Data System (ADS)

    Kim, Dae Hoe; Choi, Jae Young; Ro, Yong Man

    2013-02-01

    In breast cancer screening practice, radiologists compare multiple views during the interpretation of mammograms to detect breast cancers. Hence, it is natural that information derived from multiple mammograms can be used for computer-aided detection (CAD) system to obtain better sensitivity and/or specificity. However, similarity features derived from the combination of cranio-caudal (CC) and mediolateral oblique (MLO) views are weak for classifying masses, because a breast is elastic and deformable. In this study, therefore, a new mass classification with boosting algorithm is proposed, aiming to reduce FPs by combining the information of CC and MLO view mammograms. The proposed method has been developed under the following facts: (1) classifiers trained using similarity features are rather weak classifier; (2) boosting technique generates a single strong classifier by combining multiple weak classifiers. By combining the classifier ensemble framework with similarity features, we are able to improve mass classification performance in two-view analysis. In this study, 192 mammogram cases were collected from the public DDSM database (DB) to demonstrate the effectiveness of the proposed method in terms of improving mass classification. Results show that our proposed classifier ensemble method can improve an area under the ROC curve (AUC) of 0.7479, compared to the best single support vector machine (SVM) classifier using feature-level fusion (AUC of 0.7123). In addition, the weakness of similarity features is experimentally found to prove the feasibility of the proposed method.

  1. Boosting the Direct CP Measurement of the Higgs-Top Coupling.

    PubMed

    Buckley, Matthew R; Gonçalves, Dorival

    2016-03-01

    Characterizing the 125 GeV Higgs boson is a critical component of the physics program at the LHC Run II. In this Letter, we consider tt[over ¯]H associated production in the dileptonic mode. We demonstrate that the difference in azimuthal angle between the leptons from top decays can directly reveal the CP structure of the top-Higgs coupling with the sensitivity of the measurement substantially enhanced in the boosted Higgs regime. We first show how to access this channel via H→bb[over ¯] jet-substructure tagging, then demonstrate the ability of the new variable to measure CP. Our analysis includes all signal and background samples simulated via the MC@NLO algorithm including hadronization and underlying-event effects. Using a boosted Higgs substructure with dileptonic tops, we find that the top-Higgs coupling strength and the CP structure can be directly probed with achievable luminosity at the 13 TeV LHC.

  2. Lorentz boosted frame simulation technique in Particle-in-cell methods

    NASA Astrophysics Data System (ADS)

    Yu, Peicheng

    In this dissertation, we systematically explore the use of a simulation method for modeling laser wakefield acceleration (LWFA) using the particle-in-cell (PIC) method, called the Lorentz boosted frame technique. In the lab frame the plasma length is typically four orders of magnitude larger than the laser pulse length. Using this technique, simulations are performed in a Lorentz boosted frame in which the plasma length, which is Lorentz contracted, and the laser length, which is Lorentz expanded, are now comparable. This technique has the potential to reduce the computational needs of a LWFA simulation by more than four orders of magnitude, and is useful if there is no or negligible reflection of the laser in the lab frame. To realize the potential of Lorentz boosted frame simulations for LWFA, the first obstacle to overcome is a robust and violent numerical instability, called the Numerical Cerenkov Instability (NCI), that leads to unphysical energy exchange between relativistically drifting particles and their radiation. This leads to unphysical noise that dwarfs the real physical processes. In this dissertation, we first present a theoretical analysis of this instability, and show that the NCI comes from the unphysical coupling of the electromagnetic (EM) modes and Langmuir modes (both main and aliasing) of the relativistically drifting plasma. We then discuss the methods to eliminate them. However, the use of FFTs can lead to parallel scalability issues when there are many more cells along the drifting direction than in the transverse direction(s). We then describe an algorithm that has the potential to address this issue by using a higher order finite difference operator for the derivative in the plasma drifting direction, while using the standard second order operators in the transverse direction(s). The NCI for this algorithm is analyzed, and it is shown that the NCI can be eliminated using the same strategies that were used for the hybrid FFT

  3. Accelerating atomistic simulations through self-learning bond-boost hyperdynamics

    SciTech Connect

    Perez, Danny; Voter, Arthur F

    2008-01-01

    By altering the potential energy landscape on which molecular dynamics are carried out, the hyperdynamics method of Voter enables one to significantly accelerate the simulation state-to-state dynamics of physical systems. While very powerful, successful application of the method entails solving the subtle problem of the parametrization of the so-called bias potential. In this study, we first clarify the constraints that must be obeyed by the bias potential and demonstrate that fast sampling of the biased landscape is key to the obtention of proper kinetics. We then propose an approach by which the bond boost potential of Miron and Fichthorn can be safely parametrized based on data acquired in the course of a molecular dynamics simulation. Finally, we introduce a procedure, the Self-Learning Bond Boost method, in which the parametrization is step efficiently carried out on-the-fly for each new state that is visited during the simulation by safely ramping up the strength of the bias potential up to its optimal value. The stability and accuracy of the method are demonstrated.

  4. Rezolsta® (Darunavir/Cobicistat): First Boosted Protease Inhibitor Co-formulated with Cobicistat.

    PubMed

    Curran, Adrián; Pérez-Valero, Ignacio; Moltó, José

    2015-01-01

    Rezolsta® (darunavir/cobicistat) is the first boosted protease inhibitor in a fixed-dose combination to be approved for the treatment of HIV infection. It contains darunavir, a protease inhibitor with a well-known safety and efficacy profile, and the new pharmacokinetic enhancer cobicistat. The convenience of this combination makes boosted darunavir easier to take, thus improving adherence. Exposure to darunavir is equivalent when it is administered with cobicistat or with ritonavir. Darunavir/cobicistat-based antiretroviral therapy has shown considerable efficacy and good tolerability in several clinical trials. Data from the single-arm, open-label, phase III GS-US-216-130 trial showed virological efficacy rates comparable to those from ARTEMIS and ODIN. Darunavir/cobicistat was well tolerated; most adverse events were mild and consisted of gastrointestinal disturbances. Cobicistat inhibits transporters of creatinine in kidney tubules, thus causing a minimal and reversible reduction in estimated glomerular filtration rate. Like ritonavir, cobicistat is a strong CYP3A4 inhibitor and, as such, shares most of its drug interactions. However, inhibition by cobicistat seems to be more specific than with ritonavir, and cobicistat has no inducer effect; therefore, differences in its drug interaction profile may be observed. PMID:26035169

  5. Generalised mc × nc -stage switched-capacitor-voltage-multiplier-based boost DC-AC inverter

    NASA Astrophysics Data System (ADS)

    Chang, Yuen-Haw; Wu, Ming-Zong

    2012-01-01

    A closed-loop scheme of a generalised ? -stage (multistage) switched-capacitor-voltage-multiplier inverter (SCVMI) is proposed by combining a two-phase interleaved phase generator and a sinusoidal-pulse-width-modulation (SPWM) control for low-power boost dc-ac conversion and regulation. In this SCVMI, the power unit contains two parts: SCVM booster (front) and H-bridge (rear). The SCVM booster is composed of two ? -stage SC cells and two ? -stage SC cells in series for a boost dc-dc conversion, and these cells are operated with two-phase non-overlapping clocks of phase generator for a high conversion ratio of ? at most (like a voltage multiplier). The H-bridge consists of four switches for a dc-ac conversion, and these switches are controlled by SPWM not only for realising full-wave operation, but also for enhancing output regulation as well as robustness to source/loading variation. Further, some aspects of theoretical analysis and design are included: SCVMI formulation, steady-state/dynamic analysis, conversion ratio, power efficiency, stability, capacitance selection, output filter and control design. Finally, the closed-loop SCVMI is simulated and the hardware implemented and tested. All the results are illustrated to show the efficacy of the proposed scheme.

  6. Interpreting the CMB aberration and Doppler measurements: boost or intrinsic dipole?

    NASA Astrophysics Data System (ADS)

    Roldan, Omar; Notari, Alessio; Quartin, Miguel

    2016-06-01

    The aberration and Doppler coupling effects of the Cosmic Microwave Background (CMB) were recently measured by the Planck satellite. The most straightforward interpretation leads to a direct detection of our peculiar velocity β, consistent with the measurement of the well-known dipole. In this paper we discuss the assumptions behind such interpretation. We show that Doppler-like couplings appear from two effects: our peculiar velocity and a second order large-scale effect due to the dipolar part of the gravitational potential. We find that the two effects are exactly degenerate but only if we assume second-order initial conditions from single-field Inflation. Thus, detecting a discrepancy in the value of β from the dipole and the Doppler couplings implies the presence of a primordial non-Gaussianity. We also show that aberration-like signals likewise arise from two independent effects: our peculiar velocity and lensing due to a first order large-scale dipolar gravitational potential, independently on Gaussianity of the initial conditions. In general such effects are not degenerate and so a discrepancy between the measured β from the dipole and aberration could be accounted for by a dipolar gravitational potential. Only through a fine-tuning of the radial profile of the potential it is possible to have a complete degeneracy with a boost effect. Finally we discuss that we also expect other signatures due to integrated second order terms, which may be further used to disentangle this scenario from a simple boost.

  7. Vector prime/protein boost vaccine that overcomes defects acquired during aging and cancer.

    PubMed

    Tang, Yucheng; Akbulut, Hakan; Maynard, Jonathan; Petersen, Line; Fang, Xiangming; Zhang, Wei-Wei; Xia, Xiaoqin; Koziol, James; Linton, Phyllis-Jean; Deisseroth, Albert

    2006-10-15

    We showed that the Ad-sig-TAA/ecdCD40L vaccine induces a tumor suppressive immune response to the hMUC-1 and rH2N tumor-associated self Ags (TAA) and to the Annexin A1 tumor vascular Ag, even in mice in which anergy exists to these Ags. When the TAA/ecdCD40L protein is given s.c. as a boost following the Ad-sig-TAA/ecdCD40L vector, the levels of the TAA-specific CD8 T cells and Abs increase dramatically over that seen with vector alone, in young (2-mo-old) as well as old (18-mo-old) mice. The Abs induced against hMUC-1 react with human breast cancer. This vaccine also induces a 4-fold decrement of negative regulatory CD4CD25FOXP3-T cells in the tumor tissue of 18-mo-old mice. These results suggest that the Ad-sig-TAA/ecdCD40L vector prime-TAA/ecdCD40L protein boost vaccine platform may be valuable in reducing postsurgery recurrence in a variety of epithelial neoplasms. PMID:17015759

  8. Anchoring dipalmitoyl phosphoethanolamine to nanoparticles boosts cellular uptake and fluorine-19 magnetic resonance signal.

    PubMed

    Waiczies, Sonia; Lepore, Stefano; Sydow, Karl; Drechsler, Susanne; Ku, Min-Chi; Martin, Conrad; Lorenz, Dorothea; Schütz, Irene; Reimann, Henning M; Purfürst, Bettina; Dieringer, Matthias A; Waiczies, Helmar; Dathe, Margitta; Pohlmann, Andreas; Niendorf, Thoralf

    2015-02-12

    Magnetic resonance (MR) methods to detect and quantify fluorine ((19)F) nuclei provide the opportunity to study the fate of cellular transplants in vivo. Cells are typically labeled with (19)F nanoparticles, introduced into living organisms and tracked by (19)F MR methods. Background-free imaging and quantification of cell numbers are amongst the strengths of (19)F MR-based cell tracking but challenges pertaining to signal sensitivity and cell detection exist. In this study we aimed to overcome these limitations by manipulating the aminophospholipid composition of (19)F nanoparticles in order to promote their uptake by dendritic cells (DCs). As critical components of biological membranes, phosphatidylethanolamines (PE) were studied. Both microscopy and MR spectroscopy methods revealed a striking (at least one order of magnitude) increase in cytoplasmic uptake of (19)F nanoparticles in DCs following enrichment with 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE). The impact of enriching (19)F nanoparticles with PE on DC migration was also investigated. By manipulating the nanoparticle composition and as a result the cellular uptake we provide here one way of boosting (19)F signal per cell in order to overcome some of the limitations related to (19)F MR signal sensitivity. The boost in signal is ultimately necessary to detect and track cells in vivo.

  9. Mathematical modeling and analysis of combinational immune boost for tumor elimination

    NASA Astrophysics Data System (ADS)

    Nakada, Naoki; Nagata, Mizuho; Takeuchi, Yasuhiro; Nakaoka, Shinji

    2016-04-01

    The immune system has an ability to recognize tumor as non-self antigen, and initiates inflammatory response to eliminate tumor. A dendritic cell (DCs) population is one of immune cell subsets that specifically uptakes foreign antigen and then presents to T cells. Dendritic cell boost ex vivo is operated to enhance immune response against tumor that in general comes to fail due to several complex reasons. Although dendritic cell therapy has been operated in clinical trials by boosting tumor immune responses, less is known about dynamic behaviors generated by interactions among immune cell subsets and tumor cells. In this paper, we construct and analyze a mathematical model describing tumor killing by T cells activated by dendritic cells. A handling time representing a waiting time required for T cells to be activated during antigen presentation is incorporated in our model. Mathematical analyses imply that successful tumor elimination depends on the amount of T cells activated ex vivo when introduced. Moreover, numerical simulations imply that an immune escape basin in which tumor can escape from T cell responses increases when the handling time increases, indicating that efficient tumor elimination might result in immediate T cell inactivation due to rapid decline of antigenic stimulation.

  10. Lorentz boosted frame simulation technique in Particle-in-cell methods

    NASA Astrophysics Data System (ADS)

    Yu, Peicheng

    In this dissertation, we systematically explore the use of a simulation method for modeling laser wakefield acceleration (LWFA) using the particle-in-cell (PIC) method, called the Lorentz boosted frame technique. In the lab frame the plasma length is typically four orders of magnitude larger than the laser pulse length. Using this technique, simulations are performed in a Lorentz boosted frame in which the plasma length, which is Lorentz contracted, and the laser length, which is Lorentz expanded, are now comparable. This technique has the potential to reduce the computational needs of a LWFA simulation by more than four orders of magnitude, and is useful if there is no or negligible reflection of the laser in the lab frame. To realize the potential of Lorentz boosted frame simulations for LWFA, the first obstacle to overcome is a robust and violent numerical instability, called the Numerical Cerenkov Instability (NCI), that leads to unphysical energy exchange between relativistically drifting particles and their radiation. This leads to unphysical noise that dwarfs the real physical processes. In this dissertation, we first present a theoretical analysis of this instability, and show that the NCI comes from the unphysical coupling of the electromagnetic (EM) modes and Langmuir modes (both main and aliasing) of the relativistically drifting plasma. We then discuss the methods to eliminate them. However, the use of FFTs can lead to parallel scalability issues when there are many more cells along the drifting direction than in the transverse direction(s). We then describe an algorithm that has the potential to address this issue by using a higher order finite difference operator for the derivative in the plasma drifting direction, while using the standard second order operators in the transverse direction(s). The NCI for this algorithm is analyzed, and it is shown that the NCI can be eliminated using the same strategies that were used for the hybrid FFT

  11. The Series Connected Buck Boost Regulator Concept for High Efficiency Light Weight DC Voltage Regulation

    NASA Technical Reports Server (NTRS)

    Birchenough, Arthur G.

    2003-01-01

    Improvements in the efficiency and size of DC-DC converters have resulted from advances in components, primarily semiconductors, and improved topologies. One topology, which has shown very high potential in limited applications, is the Series Connected Boost Unit (SCBU), wherein a small DC-DC converter output is connected in series with the input bus to provide an output voltage equal to or greater than the input voltage. Since the DC-DC converter switches only a fraction of the power throughput, the overall system efficiency is very high. But this technique is limited to applications where the output is always greater than the input. The Series Connected Buck Boost Regulator (SCBBR) concept extends partial power processing technique used in the SCBU to operation when the desired output voltage is higher or lower than the input voltage, and the implementation described can even operate as a conventional buck converter to operate at very low output to input voltage ratios. This paper describes the operation and performance of an SCBBR configured as a bus voltage regulator providing 50 percent voltage regulation range, bus switching, and overload limiting, operating above 98 percent efficiency. The technique does not provide input-output isolation.

  12. High-accuracy current sensing circuit with current compensation technique for buck-boost converter

    NASA Astrophysics Data System (ADS)

    Rao, Yuan; Deng, Wan-Ling; Huang, Jun-Kai

    2015-03-01

    A novel on-chip current sensing circuit with current compensation technique suitable for buck-boost converter is presented in this article. The proposed technique can sense the full-range inductor current with high accuracy and high speed. It is mainly based on matched current mirror and does not require a large proportion of aspect ratio between the powerFET and the senseFET, thus it reduces the complexity of circuit design and the layout mismatch issue without decreasing the power efficiency. The circuit is fabricated with TSMC 0.25 µm 2P5M mixed-signal process. Simulation results show that the buck-boost converter can be operated at 200 kHz to 4 MHz switching frequency with an input voltage from 2.8 to 4.7 V. The output voltage is 3.6 V, and the maximum accuracy for both high and low side sensing current reaches 99% within the load current ranging from 200 to 600 mA.

  13. Anchoring Dipalmitoyl Phosphoethanolamine to Nanoparticles Boosts Cellular Uptake and Fluorine-19 Magnetic Resonance Signal

    NASA Astrophysics Data System (ADS)

    Waiczies, Sonia; Lepore, Stefano; Sydow, Karl; Drechsler, Susanne; Ku, Min-Chi; Martin, Conrad; Lorenz, Dorothea; Schütz, Irene; Reimann, Henning M.; Purfürst, Bettina; Dieringer, Matthias A.; Waiczies, Helmar; Dathe, Margitta; Pohlmann, Andreas; Niendorf, Thoralf

    2015-02-01

    Magnetic resonance (MR) methods to detect and quantify fluorine (19F) nuclei provide the opportunity to study the fate of cellular transplants in vivo. Cells are typically labeled with 19F nanoparticles, introduced into living organisms and tracked by 19F MR methods. Background-free imaging and quantification of cell numbers are amongst the strengths of 19F MR-based cell tracking but challenges pertaining to signal sensitivity and cell detection exist. In this study we aimed to overcome these limitations by manipulating the aminophospholipid composition of 19F nanoparticles in order to promote their uptake by dendritic cells (DCs). As critical components of biological membranes, phosphatidylethanolamines (PE) were studied. Both microscopy and MR spectroscopy methods revealed a striking (at least one order of magnitude) increase in cytoplasmic uptake of 19F nanoparticles in DCs following enrichment with 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE). The impact of enriching 19F nanoparticles with PE on DC migration was also investigated. By manipulating the nanoparticle composition and as a result the cellular uptake we provide here one way of boosting 19F signal per cell in order to overcome some of the limitations related to 19F MR signal sensitivity. The boost in signal is ultimately necessary to detect and track cells in vivo.

  14. Boosting the Direct CP Measurement of the Higgs-Top Coupling.

    PubMed

    Buckley, Matthew R; Gonçalves, Dorival

    2016-03-01

    Characterizing the 125 GeV Higgs boson is a critical component of the physics program at the LHC Run II. In this Letter, we consider tt[over ¯]H associated production in the dileptonic mode. We demonstrate that the difference in azimuthal angle between the leptons from top decays can directly reveal the CP structure of the top-Higgs coupling with the sensitivity of the measurement substantially enhanced in the boosted Higgs regime. We first show how to access this channel via H→bb[over ¯] jet-substructure tagging, then demonstrate the ability of the new variable to measure CP. Our analysis includes all signal and background samples simulated via the MC@NLO algorithm including hadronization and underlying-event effects. Using a boosted Higgs substructure with dileptonic tops, we find that the top-Higgs coupling strength and the CP structure can be directly probed with achievable luminosity at the 13 TeV LHC. PMID:26991170

  15. Coronary Artery Disease Detection Using a Fuzzy-Boosting PSO Approach

    PubMed Central

    Ghadiri Hedeshi, N.; Saniee Abadeh, M.

    2014-01-01

    In the past decades, medical data mining has become a popular data mining subject. Researchers have proposed several tools and various methodologies for developing effective medical expert systems. Diagnosing heart diseases is one of the important topics and many researchers have tried to develop intelligent medical expert systems to help the physicians. In this paper, we propose the use of PSO algorithm with a boosting approach to extract rules for recognizing the presence or absence of coronary artery disease in a patient. The weight of training examples that are classified properly by the new rules is reduced by a boosting mechanism. Therefore, in the next rule generation cycle, the focus is on those fuzzy rules that account for the currently misclassified or uncovered instances. We have used coronary artery disease data sets taken from University of California Irvine, (UCI), to evaluate our new classification approach. Results show that the proposed method can detect the coronary artery disease with an acceptable accuracy. Also, the discovered rules have significant interpretability as well. PMID:24817883

  16. Engineering RENTA, a DNA prime-MVA boost HIV vaccine tailored for Eastern and Central Africa.

    PubMed

    Nkolola, J P; Wee, E G-T; Im, E-J; Jewell, C P; Chen, N; Xu, X-N; McMichael, A J; Hanke, T

    2004-07-01

    For the development of human immunodeficiency virus type 1 (HIV-1) vaccines, traditional approaches inducing virus-neutralizing antibodies have so far failed. Thus the effort is now focused on elicitation of cellular immunity. We are currently testing in clinical trials in the United Kingdom and East Africa a T-cell vaccine consisting of HIV-1 clade A Gag-derived immunogen HIVA delivered in a prime-boost regimen by a DNA plasmid and modified vaccinia virus Ankara (MVA). Here, we describe engineering and preclinical development of a second immunogen RENTA, which will be used in combination with the present vaccine in a four-component DNA/HIVA-RENTA prime-MVA/HIVA-RENTA boost formulation. RENTA is a fusion protein derived from consensus HIV clade A sequences of Tat, reverse transcriptase, Nef and gp41. We inactivated the natural biological activities of the HIV components and confirmed immunogenicities of the pTHr.RENTA and MVA.RENTA vaccines in mice. Furthermore, we demonstrated in mice and rhesus monkeys broadening of HIVA-elicited T-cell responses by a parallel induction of HIVA- and RENTA-specific responses recognizing multiple HIV epitopes.

  17. Comparison of Traditional and Simultaneous IMRT Boost Technique Basing on Therapeutic Gain Calculation

    SciTech Connect

    Slosarek, Krzysztof; Zajusz, Aleksander; Szlag, Marta

    2008-01-01

    Two different radiotherapy techniques, a traditional one (CRT) - based on consecutive decreasing of irradiation fields during treatment, and intensity modulated radiation therapy technique (IMRT) with concomitant boost, deliver different doses to treated volumes, increasing the dose in regions of interest. The fractionation schedule differs depending on the applied technique of irradiation. The aim of this study was to compare different fractionation schedules considering tumor control and normal tissue complications. The analysis of tumor control probability (TCP) and normal tissue complication probability (NTCP) were based on the linear quadratic (LQ) model of biologically equivalent dose. A therapeutic gain (TG) formula that combines NTCP and TCP for selected irradiated volumes was introduced to compare CRT and simultaneous boost (SIB) methods. TG refers to the different doses per fraction, overall treatment time (OTT), and selected biological factors such as tumor cell and repopulation time. Therapeutic gain increases with the dose per fraction and reaches the maximum for the doses at about 3 Gy. Further increase in dose per fraction results in decrease of TG, mainly because of the escalation of NTCP. The presented TG formula allows the optimization of radiotherapy planning by comparing different treatment plans for individual patients and by selecting optimal fraction dose.

  18. Why to start the concomitant boost in accelerated radiotherapy for advanced laryngeal cancer in week 3

    SciTech Connect

    Terhaard, Chris H.J. . E-mail: C.H.J.Terhaard@AZU.nl; Kal, Henk B.; Hordijk, Gerrit-Jan

    2005-05-01

    Purpose: We analyzed toxicity and the local control rates for advanced laryngeal cancer, treated with two accelerated fractionation schedules. The main difference between the schedules was the onset of the concomitant boost, in Week 3 or Week 4. Overall treatment time and total dose were equivalent. Methods and Materials: In a prospective, nonrandomized study of T{sub 3}, T{sub 4}, and advanced T{sub 2} laryngeal cancer, concomitant boost schedules were used in 100 patients. Thirty patients received a schedule of twice daily 1.2 Gy in Weeks 1-3, followed by twice daily 1.7 Gy in Weeks 4 and 5; total dose was 70 Gy (the hyperfractionated accelerated schedule [HAS] regimen). Seventy patients were treated with 5 times 2 Gy in Weeks 1 and 2, followed by daily 1.8 Gy and 1.5 Gy (boost) in Weeks 3-5; total dose 69.5 Gy (the accelerated schedule only [ASO] regimen). Distribution of T stage was 47%, 40%, and 12% for T{sub 2}, T{sub 3}, and T{sub 4}, respectively. In 24% of the patients, lymph nodes were positive. Pretreatment tracheotomy or stridor or both occurred in 8 patients. The distribution of prognostic factors was not significantly different between the two fractionation schedules. Acute and late toxicity was assessed. Results were estimated by the use of actuarial methods. For late toxicity and local control univariate and multivariate analyses were performed. Tumor control probability analysis was used to model cure rate differences. Results: Overall acute mucositis score was equal for both schedules. Acute mucositis started and decreased significantly earlier in the HAS regimen. In all patients acute mucositis healed completely. The treatment was completed within 38 days in all patients. The regional control rate was 100% for clinical N{sub 0}, and 75% for the clinical N{sub +} patients. The 3-year local control rate was 59% and 78% for the HAS and ASO regimens, respectively (p = 0.05); the ultimate local control was 80% and 94%, respectively. In multivariate

  19. Maximum Power Point Tracking Controller for Thermoelectric Generators with Peak Gain Control of Boost DC-DC Converters

    NASA Astrophysics Data System (ADS)

    Park, Jungyong; Kim, Shiho

    2012-06-01

    An analog maximum power point tracking (MPPT) circuit for a thermoelectric generator (TEG) is proposed. We show that the peak point of the voltage conversion gain of a boost DC-DC converter with an input voltage source having an internal resistor is the maximum power point of the TEG. The key characteristic of the proposed MPPT controller is that the duty ratio of the input clock pulse to the boost DC-DC converter shifts toward the maximum power point of the TEG by seeking the peak gain point of the boost DC-DC converters. The proposed MPPT technique provides a simple and useful analog MPPT solution, without employing digital microcontroller units.

  20. Rhodiola crenulata- and Cordyceps sinensis-Based Supplement Boosts Aerobic Exercise Performance after Short-Term High Altitude Training

    PubMed Central

    Chen, Chung-Yu; Hou, Chien-Wen; Bernard, Jeffrey R.; Chen, Chiu-Chou; Hung, Ta-Cheng; Cheng, Lu-Ling; Liao, Yi-Hung

    2014-01-01

    Abstract Chen, Chung-Yu, Chien-Wen Hou, Jeffrey R. Bernard, Chiu-Chou Chen, Ta-Cheng Hung, Lu-Ling Cheng, Yi-Hung Liao, and Chia-Hua Kuo. Rhodiola crenulata- and Cordyceps sinensis-based supplement boosts aerobic exercise performance after short-term high altitude training. High Alt Med Biol 15:371–379, 2014.—High altitude training is a widely used strategy for improving aerobic exercise performance. Both Rhodiola crenulata (R) and Cordyceps sinensis (C) supplements have been reported to improve exercise performance. However, it is not clear whether the provision of R and C during high altitude training could further enhance aerobic endurance capacity. In this study, we examined the effect of R and C based supplementation on aerobic exercise capacity following 2-week high altitude training. Alterations to autonomic nervous system activity, circulatory hormonal, and hematological profiles were investigated. Eighteen male subjects were divided into two groups: Placebo (n=9) and R/C supplementation (RC, n=9). Both groups received either RC (R: 1400 mg+C: 600 mg per day) or the placebo during a 2-week training period at an altitude of 2200 m. After 2 weeks of altitude training, compared with Placebo group, the exhaustive run time was markedly longer (Placebo: +2.2% vs. RC: +5.7%; p<0.05) and the decline of parasympathetic (PNS) activity was significantly prevented in RC group (Placebo: −51% vs. RC: −41%; p<0.05). Red blood cell, hematocrit, and hemoglobin levels were elevated in both groups to a comparable extent after high altitude training (p<0.05), whereas the erythropoietin (EPO) level remained higher in the Placebo group (∼48% above RC values; p<0.05). The provision of an RC supplement during altitude training provides greater training benefits in improving aerobic performance. This beneficial effect of RC treatment may result from better maintenance of PNS activity and accelerated physiological adaptations during high altitude training. PMID