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Sample records for adaptive boosting adaboost

  1. Quantum AdaBoost algorithm via cluster state

    NASA Astrophysics Data System (ADS)

    Li, Yuan

    2017-03-01

    The principle and theory of quantum computation are investigated by researchers for many years, and further applied to improve the efficiency of classical machine learning algorithms. Based on physical mechanism, a quantum version of AdaBoost (Adaptive Boosting) training algorithm is proposed in this paper, of which purpose is to construct a strong classifier. In the proposed scheme with cluster state in quantum mechanism is to realize the weak learning algorithm, and then update the corresponding weight of examples. As a result, a final classifier can be obtained by combining efficiently weak hypothesis based on measuring cluster state to reweight the distribution of examples.

  2. Chagas Parasite Detection in Blood Images Using AdaBoost

    PubMed Central

    Uc-Cetina, Víctor; Brito-Loeza, Carlos; Ruiz-Piña, Hugo

    2015-01-01

    The Chagas disease is a potentially life-threatening illness caused by the protozoan parasite, Trypanosoma cruzi. Visual detection of such parasite through microscopic inspection is a tedious and time-consuming task. In this paper, we provide an AdaBoost learning solution to the task of Chagas parasite detection in blood images. We give details of the algorithm and our experimental setup. With this method, we get 100% and 93.25% of sensitivity and specificity, respectively. A ROC comparison with the method most commonly used for the detection of malaria parasites based on support vector machines (SVM) is also provided. Our experimental work shows mainly two things: (1) Chagas parasites can be detected automatically using machine learning methods with high accuracy and (2) AdaBoost + SVM provides better overall detection performance than AdaBoost or SVMs alone. Such results are the best ones known so far for the problem of automatic detection of Chagas parasites through the use of machine learning, computer vision, and image processing methods. PMID:25861375

  3. 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).

  4. 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.

  5. Reinforced AdaBoost learning for object detection with local pattern representations.

    PubMed

    Lee, Younghyun; Han, David K; Ko, Hanseok

    2013-01-01

    A reinforced AdaBoost learning algorithm is proposed for object detection with local pattern representations. In implementing AdaBoost learning, the proposed algorithm employs an exponential criterion as a cost function and Newton's method for its optimization. In particular, we introduce an optimal selection of weak classifiers minimizing the cost function and derive the reinforced predictions based on a judicial confidence estimate to determine the classification results. The weak classifier of the proposed method produces real-valued predictions while that of the conventional AdaBoost method produces integer valued predictions of +1 or -1. Hence, in the conventional learning algorithms, the entire sample weights are updated by the same rate. On the contrary, the proposed learning algorithm allows the sample weights to be updated individually depending on the confidence level of each weak classifier prediction, thereby reducing the number of weak classifier iterations for convergence. Experimental classification performance on human face and license plate images confirm that the proposed method requires smaller number of weak classifiers than the conventional learning algorithm, resulting in higher learning and faster classification rates. An object detector implemented based on the proposed learning algorithm yields better performance in field tests in terms of higher detection rate with lower false positives than that of the conventional learning algorithm.

  6. 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.

  7. Multiscale shape features for classification of bronchovascular anatomy in CT using AdaBoost

    NASA Astrophysics Data System (ADS)

    Ochs, Robert A.; Goldin, Jonathan G.; Abtin, Fereidoun; Kim, Hyun J.; Brown, Kathleen; Batra, Poonam; Roback, Donald; McNitt-Gray, Michael F.; Brown, Matthew S.

    2007-03-01

    Lung CAD systems require the ability to classify a variety of pulmonary structures as part of the diagnostic process. The purpose of this work was to develop a methodology for fully automated voxel-by-voxel classification of airways, fissures, nodules, and vessels from chest CT images using a single feature set and classification method. Twenty-nine thin section CT scans were obtained from the Lung Image Database Consortium (LIDC). Multiple radiologists labeled voxels corresponding to the following structures: airways (trachea to 6th generation), major and minor lobar fissures, nodules, and vessels (hilum to peripheral), and normal lung parenchyma. The labeled data was used in conjunction with a supervised machine learning approach (AdaBoost) to train a set of ensemble classifiers. Each ensemble classifier was trained to detect voxels part of a specific structure (either airway, fissure, nodule, vessel, or parenchyma). The feature set consisted of voxel attenuation and a small number of features based on the eigenvalues of the Hessian matrix (used to differentiate structures by shape) computed at multiple smoothing scales to improve the detection of both large and small structures. When each ensemble classifier was composed of 20 weak classifiers, the AUC values for the airway, fissure, nodule, vessel, and parenchyma classifiers were 0.984 +/- 0.011, 0.949 +/- 0.009, 0.945 +/- 0.018, 0.953 +/- 0.016, and 0.931+/- 0.015 respectively.

  8. Effective Classification of MicroRNA Precursors Using Feature Mining and AdaBoost Algorithms

    PubMed Central

    Zhong, Ling; Wen, Dongrong; Aris, Virginie; Soteropoulos, Patricia; Shapiro, Bruce A.

    2013-01-01

    Abstract MicroRNAs play important roles in most biological processes, including cell proliferation, tissue differentiation, and embryonic development, among others. They originate from precursor transcripts (pre-miRNAs), which contain phylogenetically conserved stem–loop structures. An important bioinformatics problem is to distinguish the pre-miRNAs from pseudo pre-miRNAs that have similar stem–loop structures. We present here a novel method for tackling this bioinformatics problem. Our method, named MirID, accepts an RNA sequence as input, and classifies the RNA sequence either as positive (i.e., a real pre-miRNA) or as negative (i.e., a pseudo pre-miRNA). MirID employs a feature mining algorithm for finding combinations of features suitable for building pre-miRNA classification models. These models are implemented using support vector machines, which are combined to construct a classifier ensemble. The accuracy of the classifier ensemble is further enhanced by the utilization of an AdaBoost algorithm. When compared with two closely related tools on twelve species analyzed with these tools, MirID outperforms the existing tools on the majority of the twelve species. MirID was also tested on nine additional species, and the results showed high accuracies on the nine species. The MirID web server is fully operational and freely accessible at http://bioinformatics.njit.edu/MirID/. Potential applications of this software in genomics and medicine are also discussed. PMID:23808606

  9. Automated classification of lung bronchovascular anatomy in CT using AdaBoost

    PubMed Central

    Ochs, Robert A.; Goldin, Jonathan G.; Abtin, Fereidoun; Kim, Hyun J.; Brown, Kathleen; Batra, Poonam; Roback, Donald; McNitt-Gray, Michael F.; Brown, Matthew S.

    2007-01-01

    Lung CAD systems require the ability to classify a variety of pulmonary structures as part of the diagnostic process. The purpose of this work was to develop a methodology for fully automated voxel-by-voxel classification of airways, fissures, nodules, and vessels from chest CT images using a single feature set and classification method. Twenty-nine thin section CT scans were obtained from the Lung Image Database Consortium (LIDC). Multiple radiologists labeled voxels corresponding to the following structures: airways (trachea to 6th generation), major and minor lobar fissures, nodules, and vessels (hilum to peripheral), and normal lung parenchyma. The labeled data was used in conjunction with a supervised machine learning approach (AdaBoost) to train a set of ensemble classifiers. Each ensemble classifier was trained to detect voxels part of a specific structure (either airway, fissure, nodule, vessel, or parenchyma). The feature set consisted of voxel attenuation and a small number of features based on the eigenvalues of the Hessian matrix (used to differentiate structures by shape). When each ensemble classifier was composed of 20 weak classifiers, the AUC values for the airway, fissure, nodule, vessel, and parenchyma classifiers were 0.984 ± 0.011, 0.949 ± 0.009, 0.945 ± 0.018, 0.953 ± 0.016, and 0.931± 0.015 respectively. The strong results suggest that this could be an effective input to higher-level anatomical based segmentation models with the potential to improve CAD performance. PMID:17482500

  10. 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.

  11. Comparison of AdaBoost and support vector machines for detecting Alzheimer's disease through automated hippocampal segmentation.

    PubMed

    Morra, Jonathan H; Tu, Zhuowen; Apostolova, Liana G; Green, Amity E; Toga, Arthur W; Thompson, Paul M

    2010-01-01

    We compared four automated methods for hippocampal segmentation using different machine learning algorithms: 1) hierarchical AdaBoost, 2) support vector machines (SVM) with manual feature selection, 3) hierarchical SVM with automated feature selection (Ada-SVM), and 4) a publicly available brain segmentation package (FreeSurfer). We trained our approaches using T1-weighted brain MRIs from 30 subjects [10 normal elderly, 10 mild cognitive impairment (MCI), and 10 Alzheimer's disease (AD)], and tested on an independent set of 40 subjects (20 normal, 20 AD). Manually segmented gold standard hippocampal tracings were available for all subjects (training and testing). We assessed each approach's accuracy relative to manual segmentations, and its power to map AD effects. We then converted the segmentations into parametric surfaces to map disease effects on anatomy. After surface reconstruction, we computed significance maps, and overall corrected p-values, for the 3-D profile of shape differences between AD and normal subjects. Our AdaBoost and Ada-SVM segmentations compared favorably with the manual segmentations and detected disease effects as well as FreeSurfer on the data tested. Cumulative p-value plots, in conjunction with the false discovery rate method, were used to examine the power of each method to detect correlations with diagnosis and cognitive scores. We also evaluated how segmentation accuracy depended on the size of the training set, providing practical information for future users of this technique.

  12. Robust Grape Cluster Detection in a Vineyard by Combining the AdaBoost Framework and Multiple Color Components

    PubMed Central

    Luo, Lufeng; Tang, Yunchao; Zou, Xiangjun; Wang, Chenglin; Zhang, Po; Feng, Wenxian

    2016-01-01

    The automatic fruit detection and precision picking in unstructured environments was always a difficult and frontline problem in the harvesting robots field. To realize the accurate identification of grape clusters in a vineyard, an approach for the automatic detection of ripe grape by combining the AdaBoost framework and multiple color components was developed by using a simple vision sensor. This approach mainly included three steps: (1) the dataset of classifier training samples was obtained by capturing the images from grape planting scenes using a color digital camera, extracting the effective color components for grape clusters, and then constructing the corresponding linear classification models using the threshold method; (2) based on these linear models and the dataset, a strong classifier was constructed by using the AdaBoost framework; and (3) all the pixels of the captured images were classified by the strong classifier, the noise was eliminated by the region threshold method and morphological filtering, and the grape clusters were finally marked using the enclosing rectangle method. Nine hundred testing samples were used to verify the constructed strong classifier, and the classification accuracy reached up to 96.56%, higher than other linear classification models. Moreover, 200 images captured under three different illuminations in the vineyard were selected as the testing images on which the proposed approach was applied, and the average detection rate was as high as 93.74%. The experimental results show that the approach can partly restrain the influence of the complex background such as the weather condition, leaves and changing illumination. PMID:27973409

  13. 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

  14. 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.

  15. 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.

  16. A novel Multi-Agent Ada-Boost algorithm for predicting protein structural class with the information of protein secondary structure.

    PubMed

    Fan, Ming; Zheng, Bin; Li, Lihua

    2015-10-01

    Knowledge of the structural class of a given protein is important for understanding its folding patterns. Although a lot of efforts have been made, it still remains a challenging problem for prediction of protein structural class solely from protein sequences. The feature extraction and classification of proteins are the main problems in prediction. In this research, we extended our earlier work regarding these two aspects. In protein feature extraction, we proposed a scheme by calculating the word frequency and word position from sequences of amino acid, reduced amino acid, and secondary structure. For an accurate classification of the structural class of protein, we developed a novel Multi-Agent Ada-Boost (MA-Ada) method by integrating the features of Multi-Agent system into Ada-Boost algorithm. Extensive experiments were taken to test and compare the proposed method using four benchmark datasets in low homology. The results showed classification accuracies of 88.5%, 96.0%, 88.4%, and 85.5%, respectively, which are much better compared with the existing methods. The source code and dataset are available on request.

  17. Multi-vehicle detection with identity awareness using cascade Adaboost and Adaptive Kalman filter for driver assistant system.

    PubMed

    Wang, Baofeng; Qi, Zhiquan; Chen, Sizhong; Liu, Zhaodu; Ma, Guocheng

    2017-01-01

    Vision-based vehicle detection is an important issue for advanced driver assistance systems. In this paper, we presented an improved multi-vehicle detection and tracking method using cascade Adaboost and Adaptive Kalman filter(AKF) with target identity awareness. A cascade Adaboost classifier using Haar-like features was built for vehicle detection, followed by a more comprehensive verification process which could refine the vehicle hypothesis in terms of both location and dimension. In vehicle tracking, each vehicle was tracked with independent identity by an Adaptive Kalman filter in collaboration with a data association approach. The AKF adaptively adjusted the measurement and process noise covariance through on-line stochastic modelling to compensate the dynamics changes. The data association correctly assigned different detections with tracks using global nearest neighbour(GNN) algorithm while considering the local validation. During tracking, a temporal context based track management was proposed to decide whether to initiate, maintain or terminate the tracks of different objects, thus suppressing the sparse false alarms and compensating the temporary detection failures. Finally, the proposed method was tested on various challenging real roads, and the experimental results showed that the vehicle detection performance was greatly improved with higher accuracy and robustness.

  18. Multi-vehicle detection with identity awareness using cascade Adaboost and Adaptive Kalman filter for driver assistant system

    PubMed Central

    Wang, Baofeng; Qi, Zhiquan; Chen, Sizhong; Liu, Zhaodu; Ma, Guocheng

    2017-01-01

    Vision-based vehicle detection is an important issue for advanced driver assistance systems. In this paper, we presented an improved multi-vehicle detection and tracking method using cascade Adaboost and Adaptive Kalman filter(AKF) with target identity awareness. A cascade Adaboost classifier using Haar-like features was built for vehicle detection, followed by a more comprehensive verification process which could refine the vehicle hypothesis in terms of both location and dimension. In vehicle tracking, each vehicle was tracked with independent identity by an Adaptive Kalman filter in collaboration with a data association approach. The AKF adaptively adjusted the measurement and process noise covariance through on-line stochastic modelling to compensate the dynamics changes. The data association correctly assigned different detections with tracks using global nearest neighbour(GNN) algorithm while considering the local validation. During tracking, a temporal context based track management was proposed to decide whether to initiate, maintain or terminate the tracks of different objects, thus suppressing the sparse false alarms and compensating the temporary detection failures. Finally, the proposed method was tested on various challenging real roads, and the experimental results showed that the vehicle detection performance was greatly improved with higher accuracy and robustness. PMID:28296902

  19. Reproducibility of hippocampal atrophy rates measured with manual, FreeSurfer, AdaBoost, FSL/FIRST and the MAPS-HBSI methods in Alzheimer's disease.

    PubMed

    Cover, Keith S; van Schijndel, Ronald A; Versteeg, Adriaan; Leung, Kelvin K; Mulder, Emma R; Jong, Remko A; Visser, Peter J; Redolfi, Alberto; Revillard, Jerome; Grenier, Baptiste; Manset, David; Damangir, Soheil; Bosco, Paolo; Vrenken, Hugo; van Dijk, Bob W; Frisoni, Giovanni B; Barkhof, Frederik

    2016-06-30

    The purpose of this study is to assess the reproducibility of hippocampal atrophy rate measurements of commonly used fully-automated algorithms in Alzheimer disease (AD). The reproducibility of hippocampal atrophy rate for FSL/FIRST, AdaBoost, FreeSurfer, MAPS independently and MAPS combined with the boundary shift integral (MAPS-HBSI) were calculated. Back-to-back (BTB) 3D T1-weighted MPRAGE MRI from the Alzheimer's Disease Neuroimaging Initiative (ADNI1) study at baseline and year one were used. Analysis on 3 groups of subjects was performed - 562 subjects at 1.5T, a 75 subject group that also had manual segmentation and 111 subjects at 3T. A simple and novel statistical test based on the binomial distribution was used that handled outlying data points robustly. Median hippocampal atrophy rates were -1.1%/year for healthy controls, -3.0%/year for mildly cognitively impaired and -5.1%/year for AD subjects. The best reproducibility was observed for MAPS-HBSI (1.3%), while the other methods tested had reproducibilities at least 50% higher at 1.5T and 3T which was statistically significant. For a clinical trial, MAPS-HBSI should require less than half the subjects of the other methods tested. All methods had good accuracy versus manual segmentation. The MAPS-HBSI method has substantially better reproducibility than the other methods considered.

  20. 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.

  1. 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

  2. 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.

  3. Adaptive guidance for an aero-assisted boost vehicle

    NASA Technical Reports Server (NTRS)

    Pamadi, Bandu N.; Taylor, Lawrence W., Jr.; Price, Douglas B.

    1988-01-01

    An adaptive guidance system incorporating dynamic pressure constraint is studied for a single stage to low earth orbit (LEO) aero-assist booster with thrust gimbal angle as the control variable. To derive an adaptive guidance law, cubic spline functions are used to represent the ascent profile. The booster flight to LEO is divided into initial and terminal phases. In the initial phase, the ascent profile is continuously updated to maximize the performance of the boost vehicle enroute. A linear feedback control is used in the terminal phase to guide the aero-assisted booster onto the desired LEO. The computer simulation of the vehicle dynamics considers a rotating spherical earth, inverse square (Newtonian) gravity field and an exponential model for the earth's atmospheric density. This adaptive guidance algorithm is capable of handling large deviations in both atmospheric conditions and modeling uncertainties, while ensuring maximum booster performance.

  4. AveBoost2: Boosting for Noisy Data

    NASA Technical Reports Server (NTRS)

    Oza, Nikunj C.

    2004-01-01

    AdaBoost is a well-known ensemble learning algorithm that constructs its constituent or base models in sequence. A key step in AdaBoost is constructing a distribution over the training examples to create each base model. This distribution, represented as a vector, is constructed to be orthogonal to the vector of mistakes made by the pre- vious base model in the sequence. The idea is to make the next base model's errors uncorrelated with those of the previous model. In previous work, we developed an algorithm, AveBoost, that constructed distributions orthogonal to the mistake vectors of all the previous models, and then averaged them to create the next base model s distribution. Our experiments demonstrated the superior accuracy of our approach. In this paper, we slightly revise our algorithm to allow us to obtain non-trivial theoretical results: bounds on the training error and generalization error (difference between training and test error). Our averaging process has a regularizing effect which, as expected, leads us to a worse training error bound for our algorithm than for AdaBoost but a superior generalization error bound. For this paper, we experimented with the data that we used in both as originally supplied and with added label noise-a small fraction of the data has its original label changed. Noisy data are notoriously difficult for AdaBoost to learn. Our algorithm's performance improvement over AdaBoost is even greater on the noisy data than the original data.

  5. 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.

  6. LDA boost classification: boosting by topics

    NASA Astrophysics Data System (ADS)

    Lei, La; Qiao, Guo; Qimin, Cao; Qitao, Li

    2012-12-01

    AdaBoost is an efficacious classification algorithm especially in text categorization (TC) tasks. The methodology of setting up a classifier committee and voting on the documents for classification can achieve high categorization precision. However, traditional Vector Space Model can easily lead to the curse of dimensionality and feature sparsity problems; so it affects classification performance seriously. This article proposed a novel classification algorithm called LDABoost based on boosting ideology which uses Latent Dirichlet Allocation (LDA) to modeling the feature space. Instead of using words or phrase, LDABoost use latent topics as the features. In this way, the feature dimension is significantly reduced. Improved Naïve Bayes (NB) is designed as the weaker classifier which keeps the efficiency advantage of classic NB algorithm and has higher precision. Moreover, a two-stage iterative weighted method called Cute Integration in this article is proposed for improving the accuracy by integrating weak classifiers into strong classifier in a more rational way. Mutual Information is used as metrics of weights allocation. The voting information and the categorization decision made by basis classifiers are fully utilized for generating the strong classifier. Experimental results reveals LDABoost making categorization in a low-dimensional space, it has higher accuracy than traditional AdaBoost algorithms and many other classic classification algorithms. Moreover, its runtime consumption is lower than different versions of AdaBoost, TC algorithms based on support vector machine and Neural Networks.

  7. 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.

  8. A boosting approach for adapting the sparsity of risk prediction signatures based on different molecular levels.

    PubMed

    Sariyar, Murat; Schumacher, Martin; Binder, Harald

    2014-06-01

    Risk prediction models can link high-dimensional molecular measurements, such as DNA methylation, to clinical endpoints. For biological interpretation, often a sparse fit is desirable. Different molecular aggregation levels, such as considering DNA methylation at the CpG, gene, or chromosome level, might demand different degrees of sparsity. Hence, model building and estimation techniques should be able to adapt their sparsity according to the setting. Additionally, underestimation of coefficients, which is a typical problem of sparse techniques, should also be addressed. We propose a comprehensive approach, based on a boosting technique that allows a flexible adaptation of model sparsity and addresses these problems in an integrative way. The main motivation is to have an automatic sparsity adaptation. In a simulation study, we show that this approach reduces underestimation in sparse settings and selects more adequate model sizes than the corresponding non-adaptive boosting technique in non-sparse settings. Using different aggregation levels of DNA methylation data from a study in kidney carcinoma patients, we illustrate how automatically selected values of the sparsity tuning parameter can reflect the underlying structure of the data. In addition to that, prediction performance and variable selection stability is compared to the non-adaptive boosting approach.

  9. 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.

  10. Boosting Adaptive Immunity: A New Role for PAFR Antagonists

    PubMed Central

    Koga, Marianna M.; Bizzarro, Bruna; Sá-Nunes, Anderson; Rios, Francisco J.; Jancar, Sonia

    2016-01-01

    We have previously shown that the Platelet-Activating Factor Receptor (PAFR) engagement in murine macrophages and dendritic cells (DCs) promotes a tolerogenic phenotype reversed by PAFR-antagonists treatment in vitro. Here, we investigated whether a PAFR antagonist would modulate the immune response in vivo. Mice were subcutaneously injected with OVA or OVA with PAFR-antagonist WEB2170 on days 0 and 7. On day 14, OVA–specific IgG2a and IgG1 were measured in the serum. The presence of WEB2170 during immunization significantly increased IgG2a without affecting IgG1 levels. When WEB2170 was added to OVA in complete Freund’s adjuvant, enhanced IgG2a but not IgG1 production was also observed, and CD4+ FoxP3+ T cell frequency in the spleen was reduced compared to mice immunized without the antagonist. Similar results were observed in PAFR-deficient mice, along with increased Tbet mRNA expression in the spleen. Additionally, bone marrow-derived DCs loaded with OVA were transferred into naïve mice and their splenocytes were co-cultured with fresh OVA-loaded DCs. CD4+ T cell proliferation was higher in the group transferred with DCs treated with the PAFR-antagonist. We propose that the activation of PAFR by ligands present in the site of immunization is able to fine-tune the adaptive immune response. PMID:27966635

  11. 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.

  12. Self-adaptive asymmetric on-line boosting for detecting anatomical structures

    NASA Astrophysics Data System (ADS)

    Wu, Hong; Tajbakhsh, Nima; Xue, Wenzhe; Liang, Jianming

    2012-03-01

    In this paper, we propose a self-adaptive, asymmetric on-line boosting (SAAOB) method for detecting anatomical structures in CT pulmonary angiography (CTPA). SAAOB is novel in that it exploits a new asymmetric loss criterion with self-adaptability according to the ratio of exposed positive and negative samples and in that it has an advanced rule to update sample's importance weight taking account of both classification result and sample's label. Our presented method is evaluated by detecting three distinct thoracic structures, the carina, the pulmonary trunk and the aortic arch, in both balanced and imbalanced conditions.

  13. 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.

  14. Load adaptive start-up scheme for synchronous boost DC-DC converter

    NASA Astrophysics Data System (ADS)

    Guoding, Dai; Wenliang, Xiu; Yuezhi, Liu; Yawei, Qi; Zuqi, Dong

    2016-10-01

    This paper presents a load adaptive soft-start scheme through which the inductor current of the synchronous boost DC-DC converter can trace the load current at the start-up stage. This scheme effectively eliminates the inrush-current and over-shoot voltage and improves the load capability of the converter. According to the output voltage, the start-up process is divided into three phases and at each phase the inductor current is limited to match the load. In the pre-charge phase, a step-increasing constant current gives a smooth rise of the output voltage which avoids inrush current and ensures the converter successfully starts up at different load situations. An additional ring oscillator operation phase enables the converter to start up as low as 1.4 V. When the converter enters into the system loop soft-start phase, an output voltage and inductor current detection methods make the transition of the phases smooth and the inductor current and output voltage rise steadily. Effective protection circuits such as short-circuit protection, current limit circuit and over-temperature protection circuit are designed to guarantee the safety and reliability of the chip during the start-up process. The proposed start-up circuit is implemented in a synchronous boost DC-DC converter based on TSMC 0.35 μm CMOS process with an input voltage range 1.4-4.2 V, and a steady output voltage 5 V, and the switching frequency is 1 MHz. Simulation results show that inrush current and overshoot voltage are suppressed with a load range from 0-2.1 A, and inductor current is as low as 259 mA when the output shorts to the ground.

  15. StructBoost: Boosting Methods for Predicting Structured Output Variables.

    PubMed

    Chunhua Shen; Guosheng Lin; van den Hengel, Anton

    2014-10-01

    Boosting is a method for learning a single accurate predictor by linearly combining a set of less accurate weak learners. Recently, structured learning has found many applications in computer vision. Inspired by structured support vector machines (SSVM), here we propose a new boosting algorithm for structured output prediction, which we refer to as StructBoost. StructBoost supports nonlinear structured learning by combining a set of weak structured learners. As SSVM generalizes SVM, our StructBoost generalizes standard boosting approaches such as AdaBoost, or LPBoost to structured learning. The resulting optimization problem of StructBoost is more challenging than SSVM in the sense that it may involve exponentially many variables and constraints. In contrast, for SSVM one usually has an exponential number of constraints and a cutting-plane method is used. In order to efficiently solve StructBoost, we formulate an equivalent 1-slack formulation and solve it using a combination of cutting planes and column generation. We show the versatility and usefulness of StructBoost on a range of problems such as optimizing the tree loss for hierarchical multi-class classification, optimizing the Pascal overlap criterion for robust visual tracking and learning conditional random field parameters for image segmentation.

  16. Adaptive Control of Fast-Scale Bifurcation in Peak Current Controlled Buck-Boost Inverter via One-Cycle Compensation

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Dong, Shuai; Guan, Weimin; Yi, Chuanzhi; He, Bo

    In this paper, one-cycle compensation (OCC) method is proposed to realize adaptive control of fast-scale bifurcation in the peak current controlled buck-boost inverter because the proposed control method can adjust the slope of the integrator’s output voltage automatically through extracting a sinusoidal signal from the absolute value of the reference voltage. In order to reveal their underlying mechanisms of fast-scale bifurcations, a modified averaged model which can capture the sample-and-hold effect is derived in detail to describe the fast-scale dynamics of the buck-boost inverter. Based on the proposed model, a theoretical analysis is performed to identify both the fast-scale period-doubling bifurcation and the fast-scale Hopf one by judging in what way the poles loci move. It has been shown that the OCC method can be used not only to discover the unknown dynamical behaviors (i.e. fast-scale Hopf bifurcation), but also to enlarge the stable region in peak current controlled buck-boost inverter. In addition, the critical bifurcation angles and the parameter behavior boundary are given to verify the effectiveness of the adaptive bifurcation control method. Finally, PSpice circuit experiments are performed to verify the above theoretical and numerical results.

  17. Adaboost and Support Vector Machines for White Matter Lesion Segmentation in MR Images.

    PubMed

    Quddus, Azhar; Fieguth, Paul; Basir, Otman

    2005-01-01

    The use of two powerful classification techniques (boosting and SVM) is explored for the segmentation of white-matter lesions in the MRI scans of human brain. Simple features are generated from Proton Density (PD) scans. Radial Basis Function (RBF) based Adaboost technique and Support Vector Machines (SVM) are employed for this task. The classifiers are trained on severe, moderate and mild cases. The segmentation is performed in T1 acquisition space rather than standard space (with more slices). Hence, the proposed approach requires less time for manual verification. The results indicate that the proposed approach can handle MR field inhomogeneities quite well and is completely independent from manual selection process so that it can be run under batch mode. Segmentation performance comparison with manual detection is also provided.

  18. Adaboost face detector based on Joint Integral Histogram and Genetic Algorithms for feature extraction process.

    PubMed

    Jammoussi, Ameni Yangui; Ghribi, Sameh Fakhfakh; Masmoudi, Dorra Sellami

    2014-01-01

    Recently, many classes of objects can be efficiently detected by the way of machine learning techniques. In practice, boosting techniques are among the most widely used machine learning for various reasons. This is mainly due to low false positive rate of the cascade structure offering the possibility to be trained by different classes of object. However, it is especially used for face detection since it is the most popular sub-problem within object detection. The challenges of Adaboost based face detector include the selection of the most relevant features from a large feature set which are considered as weak classifiers. In many scenarios, however, selection of features based on lowering classification errors leads to computation complexity and excess of memory use. In this work, we propose a new method to train an effective detector by discarding redundant weak classifiers while achieving the pre-determined learning objective. To achieve this, on the one hand, we modify AdaBoost training so that the feature selection process is not based any more on the weak learner's training error. This is by incorporating the Genetic Algorithm (GA) on the training process. On the other hand, we make use of the Joint Integral Histogram in order to extract more powerful features. Experimental performance on human faces show that our proposed method requires smaller number of weak classifiers than the conventional learning algorithm, resulting in higher learning and faster classification rates. So, our method outperforms significantly state-of-the-art cascade methods in terms of detection rate and false positive rate and especially in reducing the number of weak classifiers per stage.

  19. More pain, more gain: Blocking the opioid system boosts adaptive cognitive control.

    PubMed

    van Steenbergen, Henk; Weissman, Daniel H; Stein, Dan J; Malcolm-Smith, Susan; van Honk, Jack

    2017-03-07

    The ability to adaptively increase cognitive control in response to cognitive challenges is crucial for goal-directed behavior. Recent findings suggest that aversive arousal triggers adaptive increases of control, but the neurochemical mechanisms underlying these effects remain unclear. Given the known contributions of the opioid system to hedonic states, we investigated whether blocking this system increases adaptive control modulations. To do so, we conducted a double-blind, placebo-controlled psychopharmacological study (n=52 females) involving a Stroop-like task. Specifically, we assessed the effect of naltrexone, an opioid blocker most selective to the mu-opioid system, on two measures of adaptive control that are thought to depend differentially on aversive arousal: post-error slowing and conflict adaptation. Consistent with our hypothesis, relative to placebo, naltrexone increased post-error slowing without influencing conflict adaptation. This finding not only supports the view that aversive arousal triggers adaptive control but also reveals a novel role for the opioid system in modulating such effects.

  20. 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.

  1. Optimal schedules of fractionated radiation therapy by way of the greedy principle: biologically-based adaptive boosting

    NASA Astrophysics Data System (ADS)

    Hanin, Leonid; Zaider, Marco

    2014-08-01

    We revisit a long-standing problem of optimization of fractionated radiotherapy and solve it in considerable generality under the following three assumptions only: (1) repopulation of clonogenic cancer cells between radiation exposures follows linear birth-and-death Markov process; (2) clonogenic cancer cells do not interact with each other; and (3) the dose response function s(D) is decreasing and logarithmically concave. Optimal schedules of fractionated radiation identified in this work can be described by the following ‘greedy’ principle: give the maximum possible dose as soon as possible. This means that upper bounds on the total dose and the dose per fraction reflecting limitations on the damage to normal tissue, along with a lower bound on the time between successive fractions of radiation, determine the optimal radiation schedules completely. Results of this work lead to a new paradigm of dose delivery which we term optimal biologically-based adaptive boosting (OBBAB). It amounts to (a) subdividing the target into regions that are homogeneous with respect to the maximum total dose and maximum dose per fraction allowed by the anatomy and biological properties of the normal tissue within (or adjacent to) the region in question and (b) treating each region with an individual optimal schedule determined by these constraints. The fact that different regions may be treated to different total dose and dose per fraction mean that the number of fractions may also vary between regions. Numerical evidence suggests that OBBAB produces significantly larger tumor control probability than the corresponding conventional treatments.

  2. 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.

  3. 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

  4. Ligand Classifier of Adaptively Boosting Ensemble Decision Stumps (LiCABEDS) and its application on modeling ligand functionality for 5HT-subtype GPCR families.

    PubMed

    Ma, Chao; Wang, Lirong; Xie, Xiang-Qun

    2011-03-28

    Advanced high-throughput screening (HTS) technologies generate great amounts of bioactivity data, and this data needs to be analyzed and interpreted with attention to understand how these small molecules affect biological systems. As such, there is an increasing demand to develop and adapt cheminformatics algorithms and tools in order to predict molecular and pharmacological properties on the basis of these large data sets. In this manuscript, we report a novel machine-learning-based ligand classification algorithm, named Ligand Classifier of Adaptively Boosting Ensemble Decision Stumps (LiCABEDS), for data-mining and modeling of large chemical data sets to predict pharmacological properties in an efficient and accurate manner. The performance of LiCABEDS was evaluated through predicting GPCR ligand functionality (agonist or antagonist) using four different molecular fingerprints, including Maccs, FP2, Unity, and Molprint 2D fingerprints. Our studies showed that LiCABEDS outperformed two other popular techniques, classification tree and Naive Bayes classifier, on all four types of molecular fingerprints. Parameters in LiCABEDS, including the number of boosting iterations, initialization condition, and a "reject option" boundary, were thoroughly explored and discussed to demonstrate the capability of handling imbalanced data sets, as well as its robustness and flexibility. In addition, the detailed mathematical concepts and theory are also given to address the principle behind statistical prediction models. The LiCABEDS algorithm has been implemented into a user-friendly software package that is accessible online at http://www.cbligand.org/LiCABEDS/ .

  5. Airport runway detection in satellite images by Adaboost learning

    NASA Astrophysics Data System (ADS)

    Zongur, Ugur; Halici, Ugur; Aytekin, Orsan; Ulusoy, Ilkay

    2009-09-01

    Advances in hardware and pattern recognition techniques, along with the widespread utilization of remote sensing satellites, have urged the development of automatic target detection systems in satellite images. Automatic detection of airports is particularly essential, due to the strategic importance of these targets. In this paper, a runway detection method using a segmentation process based on textural properties is proposed for the detection of airport runways, which is the most distinguishing element of an airport. Several local textural features are extracted including not only low level features such as mean, standard deviation of image intensity and gradient, but also Zernike Moments, Circular-Mellin Features, Haralick Features, as well as features involving Gabor Filters, Wavelets and Fourier Power Spectrum Analysis. Since the subset of the mentioned features, which have a role in the discrimination of airport runways from other structures and landforms, cannot be predicted trivially, Adaboost learning algorithm is employed for both classification and determining the feature subset, due to its feature selector nature. By means of the features chosen in this way, a coarse representation of possible runway locations is obtained. Promising experimental results are achieved and given.

  6. A Parallel Adaboost-Backpropagation Neural Network for Massive Image Dataset Classification

    NASA Astrophysics Data System (ADS)

    Cao, Jianfang; Chen, Lichao; Wang, Min; Shi, Hao; Tian, Yun

    2016-12-01

    Image classification uses computers to simulate human understanding and cognition of images by automatically categorizing images. This study proposes a faster image classification approach that parallelizes the traditional Adaboost-Backpropagation (BP) neural network using the MapReduce parallel programming model. First, we construct a strong classifier by assembling the outputs of 15 BP neural networks (which are individually regarded as weak classifiers) based on the Adaboost algorithm. Second, we design Map and Reduce tasks for both the parallel Adaboost-BP neural network and the feature extraction algorithm. Finally, we establish an automated classification model by building a Hadoop cluster. We use the Pascal VOC2007 and Caltech256 datasets to train and test the classification model. The results are superior to those obtained using traditional Adaboost-BP neural network or parallel BP neural network approaches. Our approach increased the average classification accuracy rate by approximately 14.5% and 26.0% compared to the traditional Adaboost-BP neural network and parallel BP neural network, respectively. Furthermore, the proposed approach requires less computation time and scales very well as evaluated by speedup, sizeup and scaleup. The proposed approach may provide a foundation for automated large-scale image classification and demonstrates practical value.

  7. A Parallel Adaboost-Backpropagation Neural Network for Massive Image Dataset Classification

    PubMed Central

    Cao, Jianfang; Chen, Lichao; Wang, Min; Shi, Hao; Tian, Yun

    2016-01-01

    Image classification uses computers to simulate human understanding and cognition of images by automatically categorizing images. This study proposes a faster image classification approach that parallelizes the traditional Adaboost-Backpropagation (BP) neural network using the MapReduce parallel programming model. First, we construct a strong classifier by assembling the outputs of 15 BP neural networks (which are individually regarded as weak classifiers) based on the Adaboost algorithm. Second, we design Map and Reduce tasks for both the parallel Adaboost-BP neural network and the feature extraction algorithm. Finally, we establish an automated classification model by building a Hadoop cluster. We use the Pascal VOC2007 and Caltech256 datasets to train and test the classification model. The results are superior to those obtained using traditional Adaboost-BP neural network or parallel BP neural network approaches. Our approach increased the average classification accuracy rate by approximately 14.5% and 26.0% compared to the traditional Adaboost-BP neural network and parallel BP neural network, respectively. Furthermore, the proposed approach requires less computation time and scales very well as evaluated by speedup, sizeup and scaleup. The proposed approach may provide a foundation for automated large-scale image classification and demonstrates practical value. PMID:27905520

  8. A Parallel Adaboost-Backpropagation Neural Network for Massive Image Dataset Classification.

    PubMed

    Cao, Jianfang; Chen, Lichao; Wang, Min; Shi, Hao; Tian, Yun

    2016-12-01

    Image classification uses computers to simulate human understanding and cognition of images by automatically categorizing images. This study proposes a faster image classification approach that parallelizes the traditional Adaboost-Backpropagation (BP) neural network using the MapReduce parallel programming model. First, we construct a strong classifier by assembling the outputs of 15 BP neural networks (which are individually regarded as weak classifiers) based on the Adaboost algorithm. Second, we design Map and Reduce tasks for both the parallel Adaboost-BP neural network and the feature extraction algorithm. Finally, we establish an automated classification model by building a Hadoop cluster. We use the Pascal VOC2007 and Caltech256 datasets to train and test the classification model. The results are superior to those obtained using traditional Adaboost-BP neural network or parallel BP neural network approaches. Our approach increased the average classification accuracy rate by approximately 14.5% and 26.0% compared to the traditional Adaboost-BP neural network and parallel BP neural network, respectively. Furthermore, the proposed approach requires less computation time and scales very well as evaluated by speedup, sizeup and scaleup. The proposed approach may provide a foundation for automated large-scale image classification and demonstrates practical value.

  9. Boosting multi-feature visual texture classiffiers for the authentication of Jackson Pollock's drip paintings

    NASA Astrophysics Data System (ADS)

    Al-Ayyoub, Mahmoud; Irfan, Mohammad T.; Stork, David G.

    2011-03-01

    Early attempts at authentication Jackson Pollock's drip paintings based on computer image analysis were restricted to a single "fractal" or "multi-fractal" visual feature, and achieved classification nearly indistinguishable from chance. Irfan and Stork pointed out that such Pollock authentication is an instance of visual texture recognition, a large discipline that universally relies on multiple visual features, and showed that modest, but statistically significant improvement in recognition accuracy can be achieved through the use of multiple features. Our work here extends such multi-feature classification by training on more image data and images of higher resolution of both genuine Pollocks and fakes. We exploit methods for feature extraction, feature selection and classiffier techniques commonly used in pattern recognition research including Support Vector Machines (SVM), decision trees (DT), and AdaBoost. We extract features from the fractality, multifractality, pink noise patterns, topological genus, and curvature properties of the images of candidate paintings, and address learning issues that have arisen due to the small number of examples. In our experiments, we found that the unmodified classiffiers like Support Vector Machines or Decision Tree alone give low accuracies (60%), but that statistical boosting through AdaBoost leads to accuracies of nearly 75%. Thus, although our set of observations is very small, we conclude that boosting methods can improve the accuracy of multi-feature classiffication of Pollock's drip paintings.

  10. Early prediction of lung cancer based on the combination of trace element analysis in urine and an Adaboost algorithm.

    PubMed

    Tan, Chao; Chen, Hui; Xia, Chengyun

    2009-04-05

    Early detection of cancer is the key to effective treatment and long-term survival. Lung cancer is one of the most frequently occurring cancers and its early detection is particularly of interest. This work investigates the feasibility of a combination of Adaboost (ensemble from machining learning) using decision stumps as weak classifier and trace element analysis for predicting early lung cancer. A dataset involving the determination of 9 trace elements of 122 urine samples is used for illustration. Kennard and Stone (KS) algorithm coupled with an alternate re-sampling was used to realize sample set partitioning. The whole dataset was split into equally sized training and test set, which were then reversed to yield a second operating case, we called them case A and case B, respectively. The prediction results based on the Adaboost were compared with those from Fisher discriminant analysis (FDA). On the test set, the final Adaboost classifiers achieved a sensitivity of 100% for both cases, a specificity of 93.8%, 95.7%, and an overall accuracy of 95.1%, 96.7%, for case A and case B, respectively. In either case, Adaboost always achieves better performance than FDA; also, it is less sensitive to the composition of the training set compared to FDA and easy to control over-fitting. It seems that Adaboost is superior to FDA in the present task, indicating that integrating Adaboost and trace element analysis of urine can serve as a useful tool for diagnosing early lung cancer in clinical practice.

  11. 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.

  12. 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

  13. An Adaboost-backpropagation neural network for automated image sentiment classification.

    PubMed

    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.

  14. Boosted ellipsoid ARTMAP

    NASA Astrophysics Data System (ADS)

    Anagnostopoulos, Georgios C.; Georgiopoulos, Michael; Verzi, Steven J.; Heileman, Gregory L.

    2002-03-01

    Ellipsoid ARTMAP (EAM) is an adaptive-resonance-theory neural network architecture that is capable of successfully performing classification tasks using incremental learning. EAM achieves its task by summarizing labeled input data via hyper-ellipsoidal structures (categories). A major property of EAM, when using off-line fast learning, is that it perfectly learns its training set after training has completed. Depending on the classification problems at hand, this fact implies that off-line EAM training may potentially suffer from over-fitting. For such problems we present an enhancement to the basic Ellipsoid ARTMAP architecture, namely Boosted Ellipsoid ARTMAP (bEAM), that is designed to simultaneously improve the generalization properties and reduce the number of created categories for EAM's off-line fast learning. This is being accomplished by forcing EAM to be tolerant about occasional misclassification errors during fast learning. An additional advantage provided by bEAM's desing is the capability of learning inconsistent cases, that is, learning identical patterns with contradicting class labels. After we present the theory behind bEAM's enhancements, we provide some preliminary experimental results, which compare the new variant to the original EAM network, Probabilistic EAM and three different variants of the Restricted Coulomb Energy neural network on the square-in-a-square classification problem.

  15. 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.

  16. 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

  17. 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

  18. [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

  19. A dynamically adjusted mixed emphasis method for building boosting ensembles.

    PubMed

    Gomez-Verdejo, Vanessa; Arenas-Garcia, Jerónimo; Figueiras-Vidal, Aníbal R

    2008-01-01

    Progressively emphasizing samples that are difficult to classify correctly is the base for the recognized high performance of real Adaboost (RA) ensembles. The corresponding emphasis function can be written as a product of a factor that measures the quadratic error and a factor related to the proximity to the classification border; this fact opens the door to explore the potential advantages provided by using adjustable combined forms of these factors. In this paper, we introduce a principled procedure to select the combination parameter each time a new learner is added to the ensemble, just by maximizing the associated edge parameter, calling the resulting method the dynamically adapted weighted emphasis RA (DW-RA). A number of application examples illustrates the performance improvements obtained by DW-RA.

  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. Oxygen boost pump study

    NASA Technical Reports Server (NTRS)

    1975-01-01

    An oxygen boost pump is described which can be used to charge the high pressure oxygen tank in the extravehicular activity equipment from spacecraft supply. The only interface with the spacecraft is the +06 6.205 Pa supply line. The breadboard study results and oxygen tank survey are summarized and the results of the flight-type prototype design and analysis are presented.

  2. 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

  3. Classification of 5-HT(1A) receptor ligands on the basis of their binding affinities by using PSO-Adaboost-SVM.

    PubMed

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

    2009-07-29

    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-HT(1A) 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.

  4. Adaptation.

    PubMed

    Broom, Donald M

    2006-01-01

    The term adaptation is used in biology in three different ways. It may refer to changes which occur at the cell and organ level, or at the individual level, or at the level of gene action and evolutionary processes. Adaptation by cells, especially nerve cells helps in: communication within the body, the distinguishing of stimuli, the avoidance of overload and the conservation of energy. The time course and complexity of these mechanisms varies. Adaptive characters of organisms, including adaptive behaviours, increase fitness so this adaptation is evolutionary. The major part of this paper concerns adaptation by individuals and its relationships to welfare. In complex animals, feed forward control is widely used. Individuals predict problems and adapt by acting before the environmental effect is substantial. Much of adaptation involves brain control and animals have a set of needs, located in the brain and acting largely via motivational mechanisms, to regulate life. Needs may be for resources but are also for actions and stimuli which are part of the mechanism which has evolved to obtain the resources. Hence pigs do not just need food but need to be able to carry out actions like rooting in earth or manipulating materials which are part of foraging behaviour. The welfare of an individual is its state as regards its attempts to cope with its environment. This state includes various adaptive mechanisms including feelings and those which cope with disease. The part of welfare which is concerned with coping with pathology is health. Disease, which implies some significant effect of pathology, always results in poor welfare. Welfare varies over a range from very good, when adaptation is effective and there are feelings of pleasure or contentment, to very poor. A key point concerning the concept of individual adaptation in relation to welfare is that welfare may be good or poor while adaptation is occurring. Some adaptation is very easy and energetically cheap and

  5. Exercise boosts immune response.

    PubMed

    Sander, Ruth

    2012-06-29

    Ageing is associated with a decline in normal functioning of the immune system described as 'immunosenescence'. This contributes to poorer vaccine response and increased incidence of infection and malignancy seen in older people. Regular exercise can enhance vaccination response, increase T-cells and boost the function of the natural killer cells in the immune system. Exercise also lowers levels of the inflammatory cytokines that cause the 'inflamm-ageing' that is thought to play a role in conditions including cardiovascular disease; type 2 diabetes; Alzheimer's disease; osteoporosis and some cancers.

  6. 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

  7. Analytic boosted boson discrimination

    SciTech Connect

    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. 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.

  8. Boosted Beta Regression

    PubMed Central

    Schmid, Matthias; Wickler, Florian; Maloney, Kelly O.; Mitchell, Richard; Fenske, Nora; Mayr, Andreas

    2013-01-01

    Regression analysis with a bounded outcome is a common problem in applied statistics. Typical examples include regression models for percentage outcomes and the analysis of ratings that are measured on a bounded scale. In this paper, we consider beta regression, which is a generalization of logit models to situations where the response is continuous on the interval (0,1). Consequently, beta regression is a convenient tool for analyzing percentage responses. The classical approach to fit a beta regression model is to use maximum likelihood estimation with subsequent AIC-based variable selection. As an alternative to this established - yet unstable - approach, we propose a new estimation technique called boosted beta regression. With boosted beta regression estimation and variable selection can be carried out simultaneously in a highly efficient way. Additionally, both the mean and the variance of a percentage response can be modeled using flexible nonlinear covariate effects. As a consequence, the new method accounts for common problems such as overdispersion and non-binomial variance structures. PMID:23626706

  9. Boosting Wigner's nj-symbols

    NASA Astrophysics Data System (ADS)

    Speziale, Simone

    2017-03-01

    We study the SL (2 ,ℂ ) Clebsch-Gordan coefficients appearing in the Lorentzian EPRL spin foam amplitudes for loop quantum gravity. We show how the amplitudes decompose into SU(2) nj- symbols at the vertices and integrals over boosts at the edges. The integrals define edge amplitudes that can be evaluated analytically using and adapting results in the literature, leading to a pure state sum model formulation. This procedure introduces virtual representations which, in a manner reminiscent of virtual momenta in Feynman amplitudes, are off-shell of the simplicity constraints present in the theory, but with the integrands that peak at the on-shell values. We point out some properties of the edge amplitudes which are helpful for numerical and analytical evaluations of spin foam amplitudes, and suggest among other things a simpler model useful for calculations of certain lowest order amplitudes. As an application, we estimate the large spin scaling behaviour of the simpler model, on a closed foam with all 4-valent edges and Euler characteristic χ , to be Nχ -5 E +V /2. The paper contains a review and an extension of the results on SL (2 ,ℂ ) Clebsch-Gordan coefficients among unitary representations of the principal series that can be useful beyond their application to quantum gravity considered here.

  10. 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.

  11. 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.

  12. 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

  13. Boosted Random Ferns for Object Detection.

    PubMed

    Villamizar, Michael; Andrade-Cetto, Juan; Sanfeliu, Alberto; Moreno-Noguer, Francesc

    2017-03-01

    In this paper we introduce the Boosted Random Ferns (BRFs) to rapidly build discriminative classifiers for learning and detecting object categories. At the core of our approach we use standard random ferns, but we introduce four main innovations that let us bring ferns from an instance to a category level, and still retain efficiency. First, we define binary features on the histogram of oriented gradients-domain (as opposed to intensity-), allowing for a better representation of intra-class variability. Second, both the positions where ferns are evaluated within the sliding window, and the location of the binary features for each fern are not chosen completely at random, but instead we use a boosting strategy to pick the most discriminative combination of them. This is further enhanced by our third contribution, that is to adapt the boosting strategy to enable sharing of binary features among different ferns, yielding high recognition rates at a low computational cost. And finally, we show that training can be performed online, for sequentially arriving images. Overall, the resulting classifier can be very efficiently trained, densely evaluated for all image locations in about 0.1 seconds, and provides detection rates similar to competing approaches that require expensive and significantly slower processing times. We demonstrate the effectiveness of our approach by thorough experimentation in publicly available datasets in which we compare against state-of-the-art, and for tasks of both 2D detection and 3D multi-view estimation.

  14. An improved gravity compensation method for high-precision free-INS based on MEC-BP-AdaBoost

    NASA Astrophysics Data System (ADS)

    Zhou, Xiao; Yang, Gongliu; Wang, Jing; Li, Jing

    2016-12-01

    In recent years, with the rapid improvement of inertial sensors (accelerometers and gyroscopes), gravity compensation has become more important for improving navigation accuracy in inertial navigation systems (INS), especially for high-precision INS. This paper proposes a mind evolutionary computation (MEC) back propagation (BP) AdaBoost algorithm neural-network-based gravity compensation method that estimates the gravity disturbance on the track based on measured gravity data. A MEC-BP-AdaBoost network-based gravity compensation algorithm used in the training process to establish the prediction model takes the carrier position (longitude and latitude) provided by INS as the input data and the gravity disturbance as the output data, and then compensates the obtained gravity disturbance into the INS’s error equations to restrain the position error propagation. The MEC-BP-AdaBoost algorithm can not only effectively avoid BP neural networks being trapped in local extrema, but also perfectly solve the nonlinearity between the input and output data that cannot be solved by traditional interpolation methods, such as least-square collocation (LSC) interpolation. The accuracy and feasibility of the proposed interpolation method are verified through numerical tests. A comparison of several other compensation methods applied in field experiments, including LSC interpolation and traditional BP interpolation, highlights the superior performance of the proposed method. The field experiment results show that the maximum value of the position error can reduce by 28% with the proposed gravity compensation method.

  15. 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.

  16. 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.

  17. Can you boost your metabolism?

    MedlinePlus

    ... can boost your metabolism. Eating foods like green tea, caffeine, or hot chili peppers will not help ... Randell RK, Jeukendrup AE. The effect of green tea extract on fat oxidation at rest and during ...

  18. Resolving boosted jets with XCone

    NASA Astrophysics Data System (ADS)

    Thaler, Jesse; Wilkason, Thomas F.

    2015-12-01

    We show how the recently proposed XCone jet algorithm [1] smoothly interpolates between resolved and boosted kinematics. When using standard jet algorithms to reconstruct the decays of hadronic resonances like top quarks and Higgs bosons, one typically needs separate analysis strategies to handle the resolved regime of well-separated jets and the boosted regime of fat jets with substructure. XCone, by contrast, is an exclusive cone jet algorithm that always returns a fixed number of jets, so jet regions remain resolved even when (sub)jets are overlapping in the boosted regime. In this paper, we perform three LHC case studies — dijet resonances, Higgs decays to bottom quarks, and all-hadronic top pairs — that demonstrate the physics applications of XCone over a wide kinematic range.

  19. 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.

  20. 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.

  1. 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)

  2. Reweighting with Boosted Decision Trees

    NASA Astrophysics Data System (ADS)

    Rogozhnikov, Alex

    2016-10-01

    Machine learning tools are commonly used in modern high energy physics (HEP) experiments. Different models, such as boosted decision trees (BDT) and artificial neural networks (ANN), are widely used in analyses and even in the software triggers [1]. In most cases, these are classification models used to select the “signal” events from data. Monte Carlo simulated events typically take part in training of these models. While the results of the simulation are expected to be close to real data, in practical cases there is notable disagreement between simulated and observed data. In order to use available simulation in training, corrections must be introduced to generated data. One common approach is reweighting — assigning weights to the simulated events. We present a novel method of event reweighting based on boosted decision trees. The problem of checking the quality of reweighting step in analyses is also discussed.

  3. 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.

  4. 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.

  5. Where boosted significances come from

    NASA Astrophysics Data System (ADS)

    Plehn, Tilman; Schichtel, Peter; Wiegand, Daniel

    2014-03-01

    In an era of increasingly advanced experimental analysis techniques it is crucial to understand which phase space regions contribute a signal extraction from backgrounds. Based on the Neyman-Pearson lemma we compute the maximum significance for a signal extraction as an integral over phase space regions. We then study to what degree boosted Higgs strategies benefit ZH and tt¯H searches and which transverse momenta of the Higgs are most promising. We find that Higgs and top taggers are the appropriate tools, but would profit from a targeted optimization towards smaller transverse momenta. MadMax is available as an add-on to MadGraph 5.

  6. Stochastic approximation boosting for incomplete data problems.

    PubMed

    Sexton, Joseph; Laake, Petter

    2009-12-01

    Boosting is a powerful approach to fitting regression models. This article describes a boosting algorithm for likelihood-based estimation with incomplete data. The algorithm combines boosting with a variant of stochastic approximation that uses Markov chain Monte Carlo to deal with the missing data. Applications to fitting generalized linear and additive models with missing covariates are given. The method is applied to the Pima Indians Diabetes Data where over half of the cases contain missing values.

  7. 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.

  8. Multiclient Identification System Using Adaptive Probabilistic Model

    NASA Astrophysics Data System (ADS)

    Lin, Chin-Teng; Siana, Linda; Shou, Yu-Wen; Yang, Chien-Ting

    2010-12-01

    This paper aims at integrating detection and identification of human faces in a more practical and real-time face recognition system. The proposed face detection system is based on the cascade Adaboost method to improve the precision and robustness toward unstable surrounding lightings. Our Adaboost method innovates to adjust the environmental lighting conditions by histogram lighting normalization and to accurately locate the face regions by a region-based-clustering process as well. We also address on the problem of multi-scale faces in this paper by using 12 different scales of searching windows and 5 different orientations for each client in pursuit of the multi-view independent face identification. There are majorly two methodological parts in our face identification system, including PCA (principal component analysis) facial feature extraction and adaptive probabilistic model (APM). The structure of our implemented APM with a weighted combination of simple probabilistic functions constructs the likelihood functions by the probabilistic constraint in the similarity measures. In addition, our proposed method can online add a new client and update the information of registered clients due to the constructed APM. The experimental results eventually show the superior performance of our proposed system for both offline and real-time online testing.

  9. Exploiting tRNAs to Boost Virulence.

    PubMed

    Albers, Suki; Czech, Andreas

    2016-01-19

    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.

  10. 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

  11. 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.

  12. 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.

  13. Orthodontics Align Crooked Teeth and Boost Self-Esteem

    MedlinePlus

    ... desktop! more... Orthodontics Align Crooked Teeth and Boost Self- esteem Article Chapters Orthodontics Align Crooked Teeth and Boost Self- esteem Orthodontics print full article print this chapter email ...

  14. 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.

  15. 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).

  16. 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).

  17. Boosting Manufacturing through Modular Chemical Process Intensification

    SciTech Connect

    2016-12-09

    Manufacturing USA's Rapid Advancement in Process Intensification Deployment Institute will focus on developing breakthrough technologies to boost domestic energy productivity and energy efficiency by 20 percent in five years through manufacturing processes.

  18. Boosting Manufacturing through Modular Chemical Process Intensification

    ScienceCinema

    None

    2017-01-06

    Manufacturing USA's Rapid Advancement in Process Intensification Deployment Institute will focus on developing breakthrough technologies to boost domestic energy productivity and energy efficiency by 20 percent in five years through manufacturing processes.

  19. 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.

  20. Boosted Jets at the LHC

    NASA Astrophysics Data System (ADS)

    Larkoski, Andrew

    2015-04-01

    Jets are collimated streams of high-energy particles ubiquitous at any particle collider experiment and serve as proxy for the production of elementary particles at short distances. As the Large Hadron Collider at CERN continues to extend its reach to ever higher energies and luminosities, an increasingly important aspect of any particle physics analysis is the study and identification of jets, electroweak bosons, and top quarks with large Lorentz boosts. In addition to providing a unique insight into potential new physics at the tera-electron volt energy scale, high energy jets are a sensitive probe of emergent phenomena within the Standard Model of particle physics and can teach us an enormous amount about quantum chromodynamics itself. Jet physics is also invaluable for lower-level experimental issues including triggering and background reduction. It is especially important for the removal of pile-up, which is radiation produced by secondary proton collisions that contaminates every hard proton collision event in the ATLAS and CMS experiments at the Large Hadron Collider. In this talk, I will review the myriad ways that jets and jet physics are being exploited at the Large Hadron Collider. This will include a historical discussion of jet algorithms and the requirements that these algorithms must satisfy to be well-defined theoretical objects. I will review how jets are used in searches for new physics and ways in which the substructure of jets is being utilized for discriminating backgrounds from both Standard Model and potential new physics signals. Finally, I will discuss how jets are broadening our knowledge of quantum chromodynamics and how particular measurements performed on jets manifest the universal dynamics of weakly-coupled conformal field theories.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. Boost breaking in the EFT of inflation

    NASA Astrophysics Data System (ADS)

    Delacrétaz, Luca V.; Noumi, Toshifumi; Senatore, Leonardo

    2017-02-01

    If time-translations are spontaneously broken, so are boosts. This symmetry breaking pattern can be non-linearly realized by either just the Goldstone boson of time translations, or by four Goldstone bosons associated with time translations and boosts. In this paper we extend the Effective Field Theory of Multifield Inflation to consider the case in which the additional Goldstone bosons associated with boosts are light and coupled to the Goldstone boson of time translations. The symmetry breaking pattern forces a coupling to curvature so that the mass of the additional Goldstone bosons is predicted to be equal to √2H in the vast majority of the parameter space where they are light. This pattern therefore offers a natural way of generating self-interacting particles with Hubble mass during inflation. After constructing the general effective Lagrangian, we study how these particles mix and interact with the curvature fluctuations, generating potentially detectable non-Gaussian signals.

  6. Boosting Access to Government Rocket Science

    DTIC Science & Technology

    2014-10-01

    September–October 2014 8 with MSFC, through an SAA signed in 2012, using Marshall’s expertise and resources to perform wind tunnel testing on various...Defense AT&L: September–October 2014 6 Boosting Access to Government Rocket Science John F. Rice Defense AT&L: September–October 2014 6 Report...REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Boosting Access to Government Rocket Science 5a. CONTRACT NUMBER

  7. 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…

  8. Concomitant GRID boost for Gamma Knife radiosurgery

    SciTech Connect

    Ma Lijun; Kwok, Young; Chin, Lawrence S.; Simard, J. Marc; Regine, William F.

    2005-11-15

    We developed an integrated GRID boost technique for Gamma Knife radiosurgery. The technique generates an array of high dose spots within the target volume via a grid of 4-mm shots. These high dose areas were placed over a conventional Gamma Knife plan where a peripheral dose covers the full target volume. The beam weights of the 4-mm shots were optimized iteratively to maximize the integral dose inside the target volume. To investigate the target volume coverage and the dose to the adjacent normal brain tissue for the technique, we compared the GRID boosted treatment plans with conventional Gamma Knife treatment plans using physical and biological indices such as dose-volume histogram (DVH), DVH-derived indices, equivalent uniform dose (EUD), tumor control probabilities (TCP), and normal tissue complication probabilities (NTCP). We found significant increase in the target volume indices such as mean dose (5%-34%; average 14%), TCP (4%-45%; average 21%), and EUD (2%-22%; average 11%) for the GRID boost technique. No significant change in the peripheral dose coverage for the target volume was found per RTOG protocol. In addition, the EUD and the NTCP for the normal brain adjacent to the target (i.e., the near region) were decreased for the GRID boost technique. In conclusion, we demonstrated a new technique for Gamma Knife radiosurgery that can escalate the dose to the target while sparing the adjacent normal brain tissue.

  9. 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…

  10. The Attentional Boost Effect with Verbal Materials

    ERIC Educational Resources Information Center

    Mulligan, Neil W.; Spataro, Pietro; Picklesimer, Milton

    2014-01-01

    Study stimuli presented at the same time as unrelated targets in a detection task are better remembered than stimuli presented with distractors. This attentional boost effect (ABE) has been found with pictorial (Swallow & Jiang, 2010) and more recently verbal materials (Spataro, Mulligan, & Rossi-Arnaud, 2013). The present experiments…

  11. Energy Boost. Q & A with Steve Kiesner.

    ERIC Educational Resources Information Center

    Schneider, Jay W.

    2002-01-01

    Presents an interview with the director of national accounts for the Edison Electric Institute in Washington, DC about the association, its booklet on energy conservation within education facilities, and ways in which educational facilities can reduce costs by boosting energy conservation. (EV)

  12. Mediterranean Diet Plus Olive Oil a Boost to Heart Health?

    MedlinePlus

    ... gov/news/fullstory_163557.html Mediterranean Diet Plus Olive Oil a Boost to Heart Health? It enhances ... HealthDay News) -- A Mediterranean diet high in virgin olive oil may boost the protective effects of "good" ...

  13. 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

  14. 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.

  15. Gradient Boosting for Conditional Random Fields

    DTIC Science & Technology

    2014-09-23

    Information Processing Systems 26 ( NIPS ’13), pages 647–655. 2013. [4] J. Friedman. Greedy function approximation: a gradient boosting machine. Annals of...and phrases and their compositionality. In Advances in Neural Information Processing Systems 26 ( NIPS ’13), pages 3111–3119. 2013. [15] A. Quattoni, M...Collins, and T. Darrell. Conditional random fields for object recognition. In Advances in Neural Information Processing Systems 17 ( NIPS ’04), pages

  16. On-line inverse multiple instance boosting for classifier grids

    PubMed Central

    Sternig, Sabine; Roth, Peter M.; Bischof, Horst

    2012-01-01

    Classifier grids have shown to be a considerable choice for object detection from static cameras. By applying a single classifier per image location the classifier’s complexity can be reduced and more specific and thus more accurate classifiers can be estimated. In addition, by using an on-line learner a highly adaptive but stable detection system can be obtained. Even though long-term stability has been demonstrated such systems still suffer from short-term drifting if an object is not moving over a long period of time. The goal of this work is to overcome this problem and thus to increase the recall while preserving the accuracy. In particular, we adapt ideas from multiple instance learning (MIL) for on-line boosting. In contrast to standard MIL approaches, which assume an ambiguity on the positive samples, we apply this concept to the negative samples: inverse multiple instance learning. By introducing temporal bags consisting of background images operating on different time scales, we can ensure that each bag contains at least one sample having a negative label, providing the theoretical requirements. The experimental results demonstrate superior classification results in presence of non-moving objects. PMID:22556453

  17. 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.

  18. Precision Jet Substructure from Boosted Event Shapes

    NASA Astrophysics Data System (ADS)

    Feige, Ilya; Schwartz, Matthew D.; Stewart, Iain W.; Thaler, Jesse

    2012-08-01

    Jet substructure has emerged as a critical tool for LHC searches, but studies so far have relied heavily on shower Monte Carlo simulations, which formally approximate QCD at the leading-log level. We demonstrate that systematic higher-order QCD computations of jet substructure can be carried out by boosting global event shapes by a large momentum Q and accounting for effects due to finite jet size, initial-state radiation (ISR), and the underlying event (UE) as 1/Q corrections. In particular, we compute the 2-subjettiness substructure distribution for boosted Z→qq¯ events at the LHC at next-to-next-to-next-to-leading-log order. The calculation is greatly simplified by recycling known results for the thrust distribution in e+e- collisions. The 2-subjettiness distribution quickly saturates, becoming Q independent for Q≳400GeV. Crucially, the effects of jet contamination from ISR/UE can be subtracted out analytically at large Q without knowing their detailed form. Amusingly, the Q=∞ and Q=0 distributions are related by a scaling by e up to next-to-leading-log order.

  19. A multiview boosting approach to tissue segmentation

    NASA Astrophysics Data System (ADS)

    Kwak, Jin Tae; Xu, Sheng; Pinto, Peter A.; Turkbey, Baris; Bernardo, Marcelino; Choyke, Peter L.; Wood, Bradford J.

    2014-04-01

    Digitized histopathology images have a great potential for improving or facilitating current assessment tools in cancer pathology. In order to develop accurate and robust automated methods, the precise segmentation of histologic objects such epithelium, stroma, and nucleus is necessary, in the hopes of information extraction not otherwise obvious to the subjective eye. Here, we propose a multivew boosting approach to segment histology objects of prostate tissue. Tissue specimen images are first represented at different scales using a Gaussian kernel and converted into several forms such HSV and La*b*. Intensity- and texture-based features are extracted from the converted images. Adopting multiview boosting approach, we effectively learn a classifier to predict the histologic class of a pixel in a prostate tissue specimen. The method attempts to integrate the information from multiple scales (or views). 18 prostate tissue specimens from 4 patients were employed to evaluate the new method. The method was trained on 11 tissue specimens including 75,832 epithelial and 103,453 stroma pixels and tested on 55,319 epithelial and 74,945 stroma pixels from 7 tissue specimens. The technique showed 96.7% accuracy, and as summarized into a receiver operating characteristic (ROC) plot, the area under the ROC curve (AUC) of 0.983 (95% CI: 0.983-0.984) was achieved.

  20. Centaur boost pump turbine icing investigation

    NASA Technical Reports Server (NTRS)

    Rollbuhler, R. J.

    1976-01-01

    An investigation was conducted to determine if ice formation in the Centaur vehicle liquid oxygen boost pump turbine could prevent rotation of the pump and whether or not this phenomenon could have been the failure mechanism for the Titan/Centaur vehicle TC-1. The investigation consisted of a series of tests done in the LeRC Space Power Chamber Facility to evaluate evaporative cooling behavior patterns in a turbine as a function of the quantity of water trapped in the turbine and as a function of the vehicle ascent pressure profile. It was found that evaporative freezing of water in the turbine housing, due to rapid depressurization within the turbine during vehicle ascent, could result in the formation of ice that would block the turbine and prevent rotation of the boost pump. But for such icing conditions to exist it would be necessary to have significant quantities of water in the turbine and/or its components, and the turbine housing temperature would have to be colder than 40 F at vehicle liftoff.

  1. Non-boost-invariant dissipative hydrodynamics

    NASA Astrophysics Data System (ADS)

    Florkowski, Wojciech; Ryblewski, Radoslaw; Strickland, Michael; Tinti, Leonardo

    2016-12-01

    The one-dimensional non-boost-invariant evolution of the quark-gluon plasma, presumably produced during the early stages of heavy-ion collisions, is analyzed within the frameworks of viscous and anisotropic hydrodynamics. We neglect transverse dynamics and assume homogeneous conditions in the transverse plane but, differently from Bjorken expansion, we relax longitudinal boost invariance in order to study the rapidity dependence of various hydrodynamical observables. We compare the results obtained using several formulations of second-order viscous hydrodynamics with a recent approach to anisotropic hydrodynamics, which treats the large initial pressure anisotropy in a nonperturbative fashion. The results obtained with second-order viscous hydrodynamics depend on the particular choice of the second-order terms included, which suggests that the latter should be included in the most complete way. The results of anisotropic hydrodynamics and viscous hydrodynamics agree for the central hot part of the system, however, they differ at the edges where the approach of anisotropic hydrodynamics helps to control the undesirable growth of viscous corrections observed in standard frameworks.

  2. Behavior Analysis in Distance Education by Boosting Algorithms

    ERIC Educational Resources Information Center

    Zang, Wei; Lin, Fuzong

    2006-01-01

    Student behavior analysis is an active research topic in distance education in recent years. In this article, we propose a new method called Boosting to investigate students' behaviors. The Boosting Algorithm can be treated as a data mining method, trying to infer from a large amount of training data the essential factors and their relations that…

  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. A 1 MEGAWATT POLYPHASE BOOST CONVERTER-MODULATOR FOR KLYSTRON PULSE APPLICATION

    SciTech Connect

    W.A. REASS; J.D. DOSS; R.F. GRIBBLE

    2001-06-01

    This paper describes electrical design criteria and first operational results a 140 kV, 1 MW average, 11 MW peak, zero-voltage-switching 20 kHz polyphase bridge, boost converter/modulator for klystron pulse application. The DC-DC converter derives the buss voltages from a standard 13.8 kV to 2300 Y substation cast-core transformer. Energy storage and filtering is provided by self-clearing metallized hazy polypropylene traction capacitors. Three ''H-Bridge'' Insulated Gate Bipolar Transistor (IGBT) switching networks are used to generate the polyphase 20 kHz transformer primary drive waveforms. The 20 kHz drive waveforms are chirped the appropriate duration to generate the desired klystron pulse width. PWM (pulse width modulation) of the individual 20 kHz pulses is utilized to provide regulated output waveforms with adaptive feedforward and feedback techniques. The boost transformer design utilizes amorphous nanocrystalline material that provides the required low core loss at design flux levels and switching frequencies. Resonant shunt-peaking is used on the transformer secondary to boost output voltage and resonate transformer leakage inductance. With the appropriate transformer leakage inductance and peaking capacitance, zero-voltage-switching of the IGBT's is attained, minimizing switching losses. A review of these design parameters and the first results of the performance characteristics will be presented.

  5. First results of the Los Alamos polyphase boost converter-modulator

    SciTech Connect

    Doss, James D.; Gribble, R. F.; Lynch, M. T.; Rees, D. E.; Tallerico, P. J.; Reass, W. A.

    2001-01-01

    This paper describes the first full-scale electrical test results of the Los Alamos polyphase boost converter-modulator being developed for the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. The convertrr-modulator provides 140 kV, 1.2 mS, 60 Hz pulses to a 5 MW, 805 MHz klystron. The system, which has 1 MW average power, derives its +/- 1250 Volt DC buss link voltages from a standard 3-phase utility 13.8 kV to 2100 volt transformer. An SCR pre-regulator provides a soft-start function in addition to correction of line and load variations, from no-load to full-load. Energy storage is provided by low inductance self-clearing metallized hazy polypropylene traction capacitors. Each of the 3-phase H-bridge Insulated Gate Bipolar Transistor (IGBT) Pulse-Width Modulation (PWM) drivers are resonated with the amorphous nanocrystalline boost transformer and associated peaking circuits to provide zero-voltage-switching characteristics for the IGBT's. This design feature minimizes IGBT switching losses. By PWM of individual IGBT conduction angles, output pulse regulation with adaptive feedforward and feedback techniques is used to improve the klystron voltage pulse shape. In addition to the first operational results, this paper will discuss the relevant design techniques associated with the boost converter-modulator topology.

  6. 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

    2011-08-02

    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.

  7. Inflammation boosts bacteriophage transfer between Salmonella spp.

    PubMed

    Diard, Médéric; Bakkeren, Erik; Cornuault, Jeffrey K; Moor, Kathrin; Hausmann, Annika; Sellin, Mikael E; Loverdo, Claude; Aertsen, Abram; Ackermann, Martin; De Paepe, Marianne; Slack, Emma; Hardt, Wolf-Dietrich

    2017-03-17

    Bacteriophage transfer (lysogenic conversion) promotes bacterial virulence evolution. There is limited understanding of the factors that determine lysogenic conversion dynamics within infected hosts. A murine Salmonella Typhimurium (STm) diarrhea model was used to study the transfer of SopEΦ, a prophage from STm SL1344, to STm ATCC14028S. Gut inflammation and enteric disease triggered >55% lysogenic conversion of ATCC14028S within 3 days. Without inflammation, SopEΦ transfer was reduced by up to 10(5)-fold. This was because inflammation (e.g., reactive oxygen species, reactive nitrogen species, hypochlorite) triggers the bacterial SOS response, boosts expression of the phage antirepressor Tum, and thereby promotes free phage production and subsequent transfer. Mucosal vaccination prevented a dense intestinal STm population from inducing inflammation and consequently abolished SopEΦ transfer. Vaccination may be a general strategy for blocking pathogen evolution that requires disease-driven transfer of temperate bacteriophages.

  8. 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

  9. Boost type PWM HVDC transmission system

    SciTech Connect

    Ooi, B.T.; Wang, X. . Dept. of Electrical Engineering)

    1991-10-01

    This paper reports that conventional HVdc is built around the mercury arc rectifier or the thyristor which requires line commutation. The advances of fast, high power GTO's and future devices such as MCT's with turn off capabilities, are bringing PWM techniques within the range of HVdc applications. By combining PWM techniques to the boost type bridge topology, one has an alternate system of HVdc Transmission. On the ac side, the converter station has active controls over: the voltage amplitude, the voltage angle and the frequency. On the dc side, parallel connections facilitate multi-terminal load sharing by simple local controls so that redundant communication channels are not required. Bidirectional power through each station is accomplished by the reversal of the direction of dc current flow. These claims have been substantiated by experimental results from laboratory size multi-terminal models.

  10. Giving top quark effective operators a boost

    NASA Astrophysics Data System (ADS)

    Englert, Christoph; Moore, Liam; Nordström, Karl; Russell, Michael

    2016-12-01

    We investigate the prospects to systematically improve generic effective field theory-based searches for new physics in the top sector during LHC run 2 as well as the high luminosity phase. In particular, we assess the benefits of high momentum transfer final states on top EFT-fit as a function of systematic uncertainties in comparison with sensitivity expected from fully-resolved analyses focusing on t t bar production. We find that constraints are typically driven by fully-resolved selections, while boosted top quarks can serve to break degeneracies in the global fit. This demystifies and clarifies the importance of high momentum transfer final states for global fits to new interactions in the top sector from direct measurements.

  11. 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.

  12. Ventriculogram segmentation using boosted decision trees

    NASA Astrophysics Data System (ADS)

    McDonald, John A.; Sheehan, Florence H.

    2004-05-01

    Left ventricular status, reflected in ejection fraction or end systolic volume, is a powerful prognostic indicator in heart disease. Quantitative analysis of these and other parameters from ventriculograms (cine xrays of the left ventricle) is infrequently performed due to the labor required for manual segmentation. None of the many methods developed for automated segmentation has achieved clinical acceptance. We present a method for semi-automatic segmentation of ventriculograms based on a very accurate two-stage boosted decision-tree pixel classifier. The classifier determines which pixels are inside the ventricle at key ED (end-diastole) and ES (end-systole) frames. The test misclassification rate is about 1%. The classifier is semi-automatic, requiring a user to select 3 points in each frame: the endpoints of the aortic valve and the apex. The first classifier stage is 2 boosted decision-trees, trained using features such as gray-level statistics (e.g. median brightness) and image geometry (e.g. coordinates relative to user supplied 3 points). Second stage classifiers are trained using the same features as the first, plus the output of the first stage. Border pixels are determined from the segmented images using dilation and erosion. A curve is then fit to the border pixels, minimizing a penalty function that trades off fidelity to the border pixels with smoothness. ED and ES volumes, and ejection fraction are estimated from border curves using standard area-length formulas. On independent test data, the differences between automatic and manual volumes (and ejection fractions) are similar in size to the differences between two human observers.

  13. 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.

  14. 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.

  15. The reach for charged Higgs bosons with boosted bottom and boosted top jets

    NASA Astrophysics Data System (ADS)

    Sullivan, Zack; Pedersen, Keith

    2017-01-01

    At moderate values of tan(β) , a supersymmetric charged Higgs boson H+/- is expected to be difficult to find due its small cross section and large backgrounds. Using the new μx boosted bottom jet tag, and measured boosted top tagging rates from the CERN LHC, we examine the reach for TeV-scale charged Higgs bosons at 14 TeV and 100 TeV colliders in top-Higgs associated production, where the charged Higgs decays to a boosted top and bottom quark pair. We conclude that the cross section for charged Higgs bosons is indeed too small to observe at the LHC in the moderate tan(β) ``wedge region,'' but it will be possible to probe charged Higgs bosons at nearly all tan(β) up to 6 TeV at a 100 TeV collider. This work was supported by the U.S. Department of Energy under award No. DE-SC0008347.

  16. 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

  17. Boosting nitrification by membrane-attached biofilm.

    PubMed

    Wu, C Y; Ushiwaka, S; Horii, H; Yamagiwa, K

    2006-01-01

    Nitrification is a key step for reliable biological nitrogen removal. In order to enhance nitrification in the activated sludge (AS) process, membrane-attached biofilm (MAB) was incorporated in a conventional activated sludge tank. Simultaneous organic carbon removal and nitrification of the MAB incorporated activated sludge (AS + MAB) process was investigated with continuous wastewater treatment. The effluent TOC concentration of AS and the AS + MAB processes were about 6.3 mg/L and 7.9 mg/L, respectively. The TOC removal efficiency of both AS and AS + MAB were above 95% during the wastewater treatment, indicating excellent organic carbon removal performance in both processes. Little nitrification occurred in the AS process. On the contrary, successful nitrification was obtained with the AS + MAB process with nitrification efficiency of about 90%. The volumetric and surface nitrification rates were about 0.14 g/Ld and 6.5 g/m2d, respectively. The results clearly demonstrated that nitrification in the conventional AS process was boosted by MAB. Furthermore, the microfaunal population in the AS + MAB process was different from that in the AS process. The high concentration of rotifers in the AS + MAB process was expected to decrease the generation of excess sludge in the process.

  18. Acetonitrile boosts conductivity of imidazolium ionic liquids.

    PubMed

    Chaban, Vitaly V; Voroshylova, Iuliia V; Kalugin, Oleg N; Prezhdo, Oleg V

    2012-07-05

    We apply a new methodology in the force field generation (Phys. Chem. Chem. Phys.2011, 13, 7910) to study binary mixtures of five imidazolium-based room-temperature ionic liquids (RTILs) with acetonitrile (ACN). Each RTIL is composed of tetrafluoroborate (BF(4)) anion and dialkylimidazolium (MMIM) cations. The first alkyl group of MIM is methyl, and the other group is ethyl (EMIM), butyl (BMIM), hexyl (HMIM), octyl (OMIM), and decyl (DMIM). Upon addition of ACN, the ionic conductivity of RTILs increases by more than 50 times. It significantly exceeds an impact of most known solvents. Unexpectedly, long-tailed imidazolium cations demonstrate the sharpest conductivity boost. This finding motivates us to revisit an application of RTIL/ACN binary systems as advanced electrolyte solutions. The conductivity correlates with a composition of ion aggregates simplifying its predictability. Addition of ACN exponentially increases diffusion and decreases viscosity of the RTIL/ACN mixtures. Large amounts of ACN stabilize ion pairs, although they ruin greater ion aggregates.

  19. Boosted Regression Tree Models to Explain Watershed ...

    EPA Pesticide Factsheets

    Boosted regression tree (BRT) models were developed to quantify the nonlinear relationships between landscape variables and nutrient concentrations in a mesoscale mixed land cover watershed during base-flow conditions. Factors that affect instream biological components, based on the Index of Biotic Integrity (IBI), were also analyzed. Seasonal BRT models at two spatial scales (watershed and riparian buffered area [RBA]) for nitrite-nitrate (NO2-NO3), total Kjeldahl nitrogen, and total phosphorus (TP) and annual models for the IBI score were developed. Two primary factors — location within the watershed (i.e., geographic position, stream order, and distance to a downstream confluence) and percentage of urban land cover (both scales) — emerged as important predictor variables. Latitude and longitude interacted with other factors to explain the variability in summer NO2-NO3 concentrations and IBI scores. BRT results also suggested that location might be associated with indicators of sources (e.g., land cover), runoff potential (e.g., soil and topographic factors), and processes not easily represented by spatial data indicators. Runoff indicators (e.g., Hydrological Soil Group D and Topographic Wetness Indices) explained a substantial portion of the variability in nutrient concentrations as did point sources for TP in the summer months. The results from our BRT approach can help prioritize areas for nutrient management in mixed-use and heavily impacted watershed

  20. Cutting Salt a Health Boost for Kidney Patients

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_163628.html Cutting Salt a Health Boost for Kidney Patients Blood pressure ... Encouraging people with kidney disease to reduce their salt intake may help improve blood pressure and cut ...

  1. Did El Nino Weather Give Zika a Boost?

    MedlinePlus

    ... fullstory_162611.html Did El Nino Weather Give Zika a Boost? Climate phenomenon could have helped infection- ... might have aided the explosive spread of the Zika virus throughout South America, a new study reports. ...

  2. 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.

  3. Xanax, Valium May Boost Pneumonia Risk in Alzheimer's Patients

    MedlinePlus

    ... html Xanax, Valium May Boost Pneumonia Risk in Alzheimer's Patients Researchers suspect people may breathe saliva or ... 10, 2017 MONDAY, April 10, 2017 (HealthDay News) -- Alzheimer's patients given sedatives such as Valium or Xanax ...

  4. Lung-Sparing Surgery May Boost Mesothelioma Survival

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_162720.html Lung-Sparing Surgery May Boost Mesothelioma Survival Treatment nearly ... 23, 2016 (HealthDay News) -- Surgery that preserves the lung, when combined with other therapies, appears to extend ...

  5. Autism Greatly Boosts Kids' Injury Risk, Especially for Drowning

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_164198.html Autism Greatly Boosts Kids' Injury Risk, Especially for Drowning ... TUESDAY, March 21, 2017 (HealthDay News) -- Children with autism are at extremely high risk of drowning compared ...

  6. Trauma as A Teen May Boost Depression Risk Around Menopause

    MedlinePlus

    ... 164355.html Trauma as a Teen May Boost Depression Risk Around Menopause Likelihood was more than twice ... during their teens have a greater risk of depression during the years leading into menopause, a new ...

  7. A Lengthy, Stable Marriage May Boost Stroke Survival

    MedlinePlus

    ... 162542.html A Lengthy, Stable Marriage May Boost Stroke Survival Lifelong singles fared the worst, study finds ... 14, 2016 WEDNESDAY, Dec. 14, 2016 (HealthDay News) -- Stroke patients may have better odds of surviving if ...

  8. SCALING OF THE ANOMALOUS BOOST IN RELATIVISTIC JET BOUNDARY LAYER

    SciTech Connect

    Zenitani, Seiji; Hesse, Michael; Klimas, Alex

    2010-04-01

    We investigate the one-dimensional interaction of a relativistic jet and an external medium. Relativistic magnetohydrodynamic simulations show an anomalous boost of the jet fluid in the boundary layer, as previously reported. We describe the boost mechanism using an ideal relativistic fluid and magnetohydrodynamic theory. The kinetic model is also examined for further understanding. Simple scaling laws for the maximum Lorentz factor are derived, and verified by the simulations.

  9. 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

  10. FULL ELECTROMAGNETIC SIMULATION OF FREE-ELECTRON LASER AMPLIFIER PHYSICS VIA THE LORENTZ-BOOSTED FRAME APPROACH

    SciTech Connect

    Fawley, William M; Vay, Jean-Luc

    2009-04-29

    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[1]. A particularly good example is that of short wavelength free-electron lasers (FELs) in which a high energy 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 2(gamma_F)**2 for fully electromagnetic simulation. We have adapted the WARP code [2]to apply this method to several FEL problems involving coherent spontaneous emission (CSE) from pre-bunched ebeams, including that in a biharmonic undulator.

  11. 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

  12. 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

  13. How Vein Sealing Boosts Fracture Opening

    NASA Astrophysics Data System (ADS)

    Nüchter, Jens-Alexander

    2015-04-01

    an increase in the fracture opening rates. (4) At constant strain rates, the rate of fracture opening increases with increasing strain. These results suggest that vein sealing boosts the rate of fracture opening, and contributes to development of low-aspect ratio veins.

  14. Modeling dark matter subhalos in a constrained galaxy: Global mass and boosted annihilation profiles

    NASA Astrophysics Data System (ADS)

    Stref, Martin; Lavalle, Julien

    2017-03-01

    The interaction properties of cold dark matter (CDM) particle candidates, such as those of weakly interacting massive particles (WIMPs), generically lead to the structuring of dark matter on scales much smaller than typical galaxies, potentially down to ˜10-10 M⊙ . This clustering translates into a very large population of subhalos in galaxies and affects the predictions for direct and indirect dark matter searches (gamma rays and antimatter cosmic rays). In this paper, we elaborate on previous analytic works to model the Galactic subhalo population, while keeping consistent with current observational dynamical constraints on the Milky Way. In particular, we propose a self-consistent method to account for tidal effects induced by both dark matter and baryons. Our model does not strongly rely on cosmological simulations, as they can hardly be fully matched to the real Milky Way, apart from setting the initial subhalo mass fraction. Still, it allows us to recover the main qualitative features of simulated systems. It can further be easily adapted to any change in the dynamical constraints, and can be used to make predictions or derive constraints on dark matter candidates from indirect or direct searches. We compute the annihilation boost factor, including the subhalo-halo cross product. We confirm that tidal effects induced by the baryonic components of the Galaxy play a very important role, resulting in a local average subhalo mass density ≲1 % of the total local dark matter mass density, while selecting the most concentrated objects and leading to interesting features in the overall annihilation profile in the case of a sharp subhalo mass function. Values of global annihilation boost factors range from ˜2 to ˜20 , while the local annihilation rate is about boosted half as much.

  15. Improved semi-supervised online boosting for object tracking

    NASA Astrophysics Data System (ADS)

    Li, Yicui; Qi, Lin; Tan, Shukun

    2016-10-01

    The advantage of an online semi-supervised boosting method which takes object tracking problem as a classification problem, is training a binary classifier from labeled and unlabeled examples. Appropriate object features are selected based on real time changes in the object. However, the online semi-supervised boosting method faces one key problem: The traditional self-training using the classification results to update the classifier itself, often leads to drifting or tracking failure, due to the accumulated error during each update of the tracker. To overcome the disadvantages of semi-supervised online boosting based on object tracking methods, the contribution of this paper is an improved online semi-supervised boosting method, in which the learning process is guided by positive (P) and negative (N) constraints, termed P-N constraints, which restrict the labeling of the unlabeled samples. First, we train the classification by an online semi-supervised boosting. Then, this classification is used to process the next frame. Finally, the classification is analyzed by the P-N constraints, which are used to verify if the labels of unlabeled data assigned by the classifier are in line with the assumptions made about positive and negative samples. The proposed algorithm can effectively improve the discriminative ability of the classifier and significantly alleviate the drifting problem in tracking applications. In the experiments, we demonstrate real-time tracking of our tracker on several challenging test sequences where our tracker outperforms other related on-line tracking methods and achieves promising tracking performance.

  16. Maximizing boosted top identification by minimizing N-subjettiness

    NASA Astrophysics Data System (ADS)

    Thaler, Jesse; van Tilburg, Ken

    2012-02-01

    N -subjettiness is a jet shape designed to identify boosted hadronic objects such as top quarks. Given N subjet axes within a jet, N-subjettiness sums the angular distances of jet constituents to their nearest subjet axis. Here, we generalize and improve on N -subjettiness by minimizing over all possible subjet directions, using a new variant of the k-means clustering algorithm. On boosted top benchmark samples from the BOOST2010 workshop, we demonstrate that a simple cut on the 3-subjettiness to 2-subjettiness ratio yields 20% (50%) tagging efficiency for a 0.23% (4.1%) fake rate, making N -subjettiness a highly effective boosted top tagger. N-subjettiness can be modified by adjusting an angular weighting exponent, and we find that the jet broadening measure is preferred for boosted top searches. We also explore multivariate techniques, and show that additional improvements are possible using a modified Fisher discriminant. Finally, we briefly mention how our minimization procedure can be extended to the entire event, allowing the event shape N-jettiness to act as a fixed N cone jet algorithm.

  17. Study of Prominence Detection Based on Various Phone-Specific Features

    NASA Astrophysics Data System (ADS)

    Kim, Sung Soo; Han, Chang Woo; Kim, Nam Soo

    In this letter, we present useful features accounting for pronunciation prominence and propose a classification technique for prominence detection. A set of phone-specific features are extracted based on a forced alignment of the test pronunciation provided by a speech recognition system. These features are then applied to the traditional classifiers such as the support vector machine (SVM), artificial neural network (ANN) and adaptive boosting (Adaboost) for detecting the place of prominence.

  18. 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

  19. 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.

  20. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2009-01-01

    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 γF, 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 γF2 for fully electromagnetic 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 of the radiation field.

  2. Conditional Random Field (CRF)-Boosting: Constructing a Robust Online Hybrid Boosting Multiple Object Tracker Facilitated by CRF Learning

    PubMed Central

    Yang, Ehwa; Gwak, Jeonghwan; Jeon, Moongu

    2017-01-01

    Due to the reasonably acceptable performance of state-of-the-art object detectors, tracking-by-detection is a standard strategy for visual multi-object tracking (MOT). In particular, online MOT is more demanding due to its diverse applications in time-critical situations. A main issue of realizing online MOT is how to associate noisy object detection results on a new frame with previously being tracked objects. In this work, we propose a multi-object tracker method called CRF-boosting which utilizes a hybrid data association method based on online hybrid boosting facilitated by a conditional random field (CRF) for establishing online MOT. For data association, learned CRF is used to generate reliable low-level tracklets and then these are used as the input of the hybrid boosting. To do so, while existing data association methods based on boosting algorithms have the necessity of training data having ground truth information to improve robustness, CRF-boosting ensures sufficient robustness without such information due to the synergetic cascaded learning procedure. Further, a hierarchical feature association framework is adopted to further improve MOT accuracy. From experimental results on public datasets, we could conclude that the benefit of proposed hybrid approach compared to the other competitive MOT systems is noticeable. PMID:28304366

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

    PubMed

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

    2012-12-04

    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.

  4. A methodology for boost-glide transport technology planning

    NASA Technical Reports Server (NTRS)

    Repic, E. M.; Olson, G. A.; Milliken, R. J.

    1974-01-01

    A systematic procedure is presented by which the relative economic value of technology factors affecting design, configuration, and operation of boost-glide transport can be evaluated. Use of the methodology results in identification of first-order economic gains potentially achievable by projected advances in each of the definable, hypersonic technologies. Starting with a baseline vehicle, the formulas, procedures and forms which are integral parts of this methodology are developed. A demonstration of the methodology is presented for one specific boost-glide system.

  5. 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.

  6. Buck-boost converter feedback controller design via evolutionary search

    NASA Astrophysics Data System (ADS)

    Sundareswaran, K.; Devi, V.; Nadeem, S. K.; Sreedevi, V. T.; Palani, S.

    2010-11-01

    Buck-boost converters are switched power converters. The model of the converter system varies from the ON state to the OFF state and hence traditional methods of controller design based on approximate transfer function models do not yield good dynamic response at different operating points of the converter system. This article attempts to design a feedback controller for a buck-boost type dc-dc converter using a genetic algorithm. The feedback controller design is perceived as an optimisation problem and a robust controller is estimated through an evolutionary search. Extensive simulation and experimental results provided in the article show the effectiveness of the new approach.

  7. Multivalent immunity targeting tumor-associated antigens by intra-lymph node DNA-prime, peptide-boost vaccination.

    PubMed

    Smith, K A; Qiu, Z; Wong, R; Tam, V L; Tam, B L; Joea, D K; Quach, A; Liu, X; Pold, M; Malyankar, U M; Bot, A

    2011-01-01

    Active immunotherapy of cancer has yet to yield effective therapies in the clinic. To evaluate the translatability of DNA-based vaccines we analyzed the profile of T-cell immunity by plasmid vaccination in a murine model, using transcriptome microarray analysis and flow cytometry. DNA vaccination resulted in specific T cells expressing low levels of co-inhibitory molecules (most notably PD-1), strikingly different from the expression profile elicited by peptide immunization. In addition, the T-cell response primed through this dual-antigen-expressing plasmid (MART-1/Melan-A and tyrosinase) translated into a substantial proliferation capacity and functional conversion to antitumor effector cells after tyrosinase and MART-1/Melan-A peptide analog boost. Furthermore, peptide boost rescued the immune response against the subdominant tyrosinase epitope. This immunization approach could be adapted to elicit potent immunity against multiple tumor antigens, resulting in a broader immune response that was more effective in targeting human tumor cells. Finally, this study sheds light on a novel mechanism of immune homeostasis through synchronous regulation of co-inhibitory molecules on T cells, highly relevant to heterologous prime boost approaches involving DNA vaccines as priming agents.

  8. Mimotope vaccine efficacy gets a "boost" from native tumor antigens.

    PubMed

    Buhrman, Jonathan D; Slansky, Jill E

    2013-04-01

    Tumor-associated antigen (TAA)-targeting mimotope peptides exert more prominent immunostimulatory functions than unmodified TAAs, with the caveat that some T-cell clones exhibit a relatively low affinity for TAAs. Combining mimotope-based vaccines with native TAAs in a prime-boost setting significantly improves antitumor immunity.

  9. Repetitive peptide boosting progressively enhances functional memory CTLs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Induction of functional memory CTLs holds promise for fighting critical infectious diseases through vaccination, but so far, no effective regime has been identified. We show here that memory CTLs can be enhanced progressively to high levels by repetitive intravenous boosting with peptide and adjuvan...

  10. 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…

  11. 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.

  12. 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 ...

  13. 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.

  14. Boost glycemic control in teen diabetics through 'family focused teamwork'.

    PubMed

    2003-09-01

    While family conflict during the teenaged years is typical, it can have long-term health consequences when it involves an adolescent with diabetes. However, researchers at Joslin Diabetes Center in Boston have developed a low-cost intervention that aims to remove conflict from disease management responsibilities--and a new study shows that it can boost glycemic control as well.

  15. Heterologous Prime-Boost Immunisation Regimens Against Infectious Diseases

    DTIC Science & Technology

    2006-08-01

    Heterologous Prime-Boost Immunisation Regimens Against Infectious Diseases Susan Shahin and David Proll Human Protection and... diseases (such as malaria, tuberculosis and HIV) has been hindered by the lack of effective immunisation strategies that induce the cellular arm of...different animal and disease models. Since several intracellular pathogens are considered potential biowarfare threats, the objective of this review

  16. 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…

  17. Sleep after vaccination boosts immunological memory.

    PubMed

    Lange, Tanja; Dimitrov, Stoyan; Bollinger, Thomas; Diekelmann, Susanne; Born, Jan

    2011-07-01

    Sleep regulates immune functions. We asked whether sleep can influence immunological memory formation. Twenty-seven healthy men were vaccinated against hepatitis A three times, at weeks 0, 8, and 16 with conditions of sleep versus wakefulness in the following night. Sleep was recorded polysomnographically, and hormone levels were assessed throughout the night. Vaccination-induced Th cell and Ab responses were repeatedly monitored for 1 y. Compared with the wake condition, sleep after vaccination doubled the frequency of Ag-specific Th cells and increased the fraction of Th1 cytokine-producing cells in this population. Moreover, sleep markedly increased Ag-specific IgG1. The effects were followed up for 1 y and were associated with high sleep slow-wave activity during the postvaccination night as well as with accompanying levels of immunoregulatory hormones (i.e., increased growth hormone and prolactin but decreased cortisol release). Our findings provide novel evidence that sleep promotes human Th1 immune responses, implicating a critical role for slow-wave sleep in this process. The proinflammatory milieu induced during this sleep stage apparently acts as adjuvant that facilitates the transfer of antigenic information from APCs to Ag-specific Th cells. Like the nervous system, the immune system takes advantage of the offline conditions during sleep to foster adaptive immune responses resulting in improved immunological memory.

  18. 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.

  19. Contribution of TLR4 and MyD88 for adjuvant monophosphoryl lipid A (MPLA) activity in a DNA prime-protein boost HIV-1 vaccine.

    PubMed

    Pouliot, Kimberly; Buglione-Corbett, Rachel; Marty-Roix, Robyn; Montminy-Paquette, Sara; West, Kim; Wang, Shixia; Lu, Shan; Lien, Egil

    2014-09-03

    Recombinant protein vaccines are commonly formulated with an immune-stimulatory compound, or adjuvant, to boost immune responses to a particular antigen. Recent studies have shown that, through recognition of molecular motifs, receptors of the innate immune system are involved in the functions of adjuvants to generate and direct adaptive immune responses. However, it is not clear to which degree those receptors are also important when the adjuvant is used as part of a novel heterologous prime-boost immunization process in which the priming and boosting components are not the same type of vaccines. In the current study, we compared the immune responses elicited by a pentavalent HIV-1 DNA prime-protein boost vaccine in mice deficient in either Toll-like receptor 4 (TLR4) or myeloid differentiation primary response gene 88 (MyD88) to wildtype mice. HIV gp120 protein administered in the boost phase was formulated with either monophosphoryl lipid A (MPLA), QS-21, or Al(OH)3. Endpoint antibody titer, serum cytokine response and T-cell memory response were assessed. Neither TLR4 nor MyD88 deficiency had a significant effect on the immune response of mice given vaccine formulated with QS-21 or Al(OH)3. However, TLR4- and MyD88-deficiency decreased both the antibody and T-cell responses in mice administered HIV gp120 formulated with MPLA. These results further our understanding of the activation of TLR4 and MyD88 by MPLA in the context of a DNA prime/protein boost immunization strategy.

  20. 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.

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

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Power boost and power-operated...

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

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Power boost and power-operated...

  3. Visual Adaptation

    PubMed Central

    Webster, Michael A.

    2015-01-01

    Sensory systems continuously mold themselves to the widely varying contexts in which they must operate. Studies of these adaptations have played a long and central role in vision science. In part this is because the specific adaptations remain a powerful tool for dissecting vision, by exposing the mechanisms that are adapting. That is, “if it adapts, it's there.” Many insights about vision have come from using adaptation in this way, as a method. A second important trend has been the realization that the processes of adaptation are themselves essential to how vision works, and thus are likely to operate at all levels. That is, “if it's there, it adapts.” This has focused interest on the mechanisms of adaptation as the target rather than the probe. Together both approaches have led to an emerging insight of adaptation as a fundamental and ubiquitous coding strategy impacting all aspects of how we see. PMID:26858985

  4. 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.

  5. 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.

  6. Black brane entropy and hydrodynamics: The boost-invariant case

    SciTech Connect

    Booth, Ivan; Heller, Michal P.; Spalinski, Michal

    2009-12-15

    The framework of slowly evolving horizons is generalized to the case of black branes in asymptotically anti-de Sitter spaces in arbitrary dimensions. The results are used to analyze the behavior of both event and apparent horizons in the gravity dual to boost-invariant flow. These considerations are motivated by the fact that at second order in the gradient expansion the hydrodynamic entropy current in the dual Yang-Mills theory appears to contain an ambiguity. This ambiguity, in the case of boost-invariant flow, is linked with a similar freedom on the gravity side. This leads to a phenomenological definition of the entropy of black branes. Some insights on fluid/gravity duality and the definition of entropy in a time-dependent setting are elucidated.

  7. Boost capacity, slash LWBS rate with POD triage system.

    PubMed

    2011-04-01

    With bottlenecks boosting ED wait times as well as the LWBS rate, Methodist Hospital of Sacramento decided to boost its triage capacity by taking over six beds that were being used for fast-track patients, and by taking advantage of waiting-room space for patients who don't need to be placed in beds. Within a month of implementing the new approach, the LWBS rate dropped to less than 2%, and door-to-doc time was slashed by 20 minutes. Under the POD system, providers have 15 minutes to determine whether patients should be discharged, sent back to the waiting room while tests are conducted, or placed in an ED bed where they can be monitored. To implement the approach, no alterations in physician staffing were needed, but the hospital added a triage nurse and a task nurse to manage patient flow of the triage POD.

  8. 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.

  9. IMM tracking of a theater ballistic missile during boost phase

    NASA Astrophysics Data System (ADS)

    Hutchins, Robert G.; San Jose, Anthony

    1998-09-01

    Since the SCUD launches in the Gulf War, theater ballistic missile (TBM) systems have become a growing concern for the US military. Detection, tracking and engagement during boost phase or shortly after booster cutoff are goals that grow in importance with the proliferation of weapons of mass destruction. This paper addresses the performance of tracking algorithms for TBMs during boost phase and across the transition to ballistic flight. Three families of tracking algorithms are examined: alpha-beta-gamma trackers, Kalman-based trackers, and the interactive multiple model (IMM) tracker. In addition, a variation on the IMM to include prior knowledge of a booster cutoff parameter is examined. Simulated data is used to compare algorithms. Also, the IMM tracker is run on an actual ballistic missile trajectory. Results indicate that IMM trackers show significant advantage in tracking through the model transition represented by booster cutoff.

  10. High Efficient Universal Buck Boost Solar Array Regulator SAR Module

    NASA Astrophysics Data System (ADS)

    Kimmelmann, Stefan; Knorr, Wolfgang

    2014-08-01

    The high efficient universal Buck Boost Solar Array Regulator (SAR) module concept is applicable for a wide range of input and output voltages. The single point failure tolerant SAR module contains 3 power converters for the transfer of the SAR power to the battery dominated power bus. The converters are operating parallel in a 2 out of 3 redundancy and are driven by two different controllers. The output power of one module can be adjusted up to 1KW depending on the requirements. The maximum power point tracker (MPPT) is placed on a separate small printed circuit board and can be used if no external tracker signal is delivered. Depending on the mode and load conditions an efficiency of more than 97% is achievable. The stable control performance is achieved by implementing the magnetic current sense detection. The sensed power coil current is used in Buck and Boost control mode.

  11. 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.

  12. Motivating quantum field theory: the boosted particle in a box

    NASA Astrophysics Data System (ADS)

    Vutha, Amar C.

    2013-07-01

    It is a maxim often stated, yet rarely illustrated, that the combination of special relativity and quantum mechanics necessarily leads to quantum field theory. An elementary illustration is provided using the familiar particle in a box, boosted to relativistic speeds. It is shown that quantum fluctuations of momentum lead to energy fluctuations, which are inexplicable without a framework that endows the vacuum with dynamical degrees of freedom and allows particle creation/annihilation.

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

    SciTech Connect

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

    2016-11-21

    A new physical principle has emerged to produce record voltages and efficiencies in photovoltaic cells, 'luminescence extraction.' This is exemplified by the mantra 'a good solar cell should also be a good LED.' Luminescence extraction is the escape of internal photons out of the front surface of a solar cell. Basic thermodynamics says that the voltage boost should be related to concentration ratio, C, of a resource by ..delta..V=(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}, so one would expect a voltage boost of ..delta..V=kT 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 ..delta..V=(kT/q)ln{n2}, ..delta..V=(kT/q)ln{2n2}, or ..delta..V=(kT/q)ln{4n2}? What is responsible for this voltage ambiguity ..delta..V=(kT/q)ln{4}=36mVolts? 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}q..delta..V/kT)<;ln{4n2}.

  14. 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...

  15. Stereotactic Body Radiation Therapy Boost in Locally Advanced Pancreatic Cancer

    SciTech Connect

    Seo, Young Seok; Kim, Mi-Sook; Yoo, Sung Yul; Cho, Chul Koo; Yang, Kwang Mo; Yoo, Hyung Jun; Choi, Chul Won; Lee, Dong Han; Kim, Jin; Kim, Min Suk; Kang, Hye Jin; Kim, YoungHan

    2009-12-01

    Purpose: To investigate the clinical application of a stereotactic body radiation therapy (SBRT) boost in locally advanced pancreatic cancer patients with a focus on local efficacy and toxicity. Methods and Materials: We retrospectively reviewed 30 patients with locally advanced and nonmetastatic pancreatic cancer who had been treated between 2004 and 2006. Follow-up duration ranged from 4 to 41 months (median, 14.5 months). A total dose of 40 Gy was delivered in 20 fractions using a conventional three-field technique, and then a single fraction of 14, 15, 16, or 17 Gy SBRT was administered as a boost without a break. Twenty-one patients received chemotherapy. Overall and local progression-free survival were calculated and prognostic factors were evaluated. Results: One-year overall survival and local progression-free survival rates were 60.0% and 70.2%, respectively. One patient (3%) developed Grade 4 toxicity. Carbohydrate antigen 19-9 response was found to be an independent prognostic factor for survival. Conclusions: Our findings indicate that a SBRT boost provides a safe means of increasing radiation dose. Based on the results of this study, we recommend that a well controlled Phase II study be conducted on locally advanced pancreatic cancer.

  16. Action Classification by Joint Boosting Using Spatiotemporal and Depth Information

    NASA Astrophysics Data System (ADS)

    Ikemura, Sho; Fujiyoshi, Hironobu

    This paper presents a method for action classification by using Joint Boosting with depth information obtained by TOF camera. Our goal is to classify action of a customer who takes the goods from each of the upper, middle and lower shelf in the supermarkets and convenience stores. Our method detects of human region by using Pixel State Analysis (PSA) from the depth image stream obtained by TOF camera, and extracts the PSA features captured from human-motion and the depth features (peak value of depth) captured from the information of human-height. We employ Joint Boosting, which is a multi-class classification of boosting method, to perform the action classification. Since the proposed method employs spatiotemporal and depth feature, it is possible to perform the detection of action for taking the goods and the classification of the height of the shelf simultaneously. Experimental results show that our method using PSA feature and peak value of depth achieved a classification rate of 93.2%. It also had a 3.1% higher performance than that of the CHLAC feature, and 2.8% higher performance than that of the ST-patch feature.

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. Single-Phase Boost Rectifier with Snubber Energy Recovery Feature

    NASA Astrophysics Data System (ADS)

    Neba, Yasuhiko; Ishizaka, Kouichi; Matsumoto, Hirokazu; Itoh, Ryozo

    Single-phase boost rectifier with snubber energy recovery feature operating under the current-mode control with a turn-on at constant clock time is studied. In this rectifier, the resonant circuit consisting of small inductor and capacitor is added in DC circuit. The snubber energy is transferred to an additional resonant capacitor and can next be transferred to the load circuit when an insulated-gate bipolar transistor as the active power device is turned off. The experimental prototype is implemented to investigate the operation. The experimental results confirm that the proposed snubber energy recovery scheme has the feasibility.

  2. Boosting alternating decision trees modeling of disease trait information.

    PubMed

    Liu, Kuang-Yu; Lin, Jennifer; Zhou, Xiaobo; Wong, Stephen T C

    2005-12-30

    We applied the alternating decision trees (ADTrees) method to the last 3 replicates from the Aipotu, Danacca, Karangar, and NYC populations in the Problem 2 simulated Genetic Analysis Workshop dataset. Using information from the 12 binary phenotypes and sex as input and Kofendrerd Personality Disorder disease status as the outcome of ADTrees-based classifiers, we obtained a new quantitative trait based on average prediction scores, which was then used for genome-wide quantitative trait linkage (QTL) analysis. ADTrees are machine learning methods that combine boosting and decision trees algorithms to generate smaller and easier-to-interpret classification rules. In this application, we compared four modeling strategies from the combinations of two boosting iterations (log or exponential loss functions) coupled with two choices of tree generation types (a full alternating decision tree or a classic boosting decision tree). These four different strategies were applied to the founders in each population to construct four classifiers, which were then applied to each study participant. To compute average prediction score for each subject with a specific trait profile, such a process was repeated with 10 runs of 10-fold cross validation, and standardized prediction scores obtained from the 10 runs were averaged and used in subsequent expectation-maximization Haseman-Elston QTL analyses (implemented in GENEHUNTER) with the approximate 900 SNPs in Hardy-Weinberg equilibrium provided for each population. Our QTL analyses on the basis of four models (a full alternating decision tree and a classic boosting decision tree paired with either log or exponential loss function) detected evidence for linkage (Z >or= 1.96, p < 0.01) on chromosomes 1, 3, 5, and 9. Moreover, using average iteration and abundance scores for the 12 phenotypes and sex as their relevancy measurements, we found all relevant phenotypes for all four populations except phenotype b for the Karangar population

  3. A Compensation-Based Optimization Methodology for Gain-Boosted OPAMP

    DTIC Science & Technology

    2004-05-14

    Reprint_._ 4. TiLu AWo 3UNTnU S. FUNDNIG UUMEAS A Compensation-Based Optimization Methodollogy for N00014-94-1-0931 Gain-Boosted OPAMP Jie Yuan and Nabil...Unlimited 13. •SW.&•CT %Af~xum200l..uord,) A gain-boosted OPAMP design methodology is presented. The methodology provides a systematic way of gain...boosted OPAMP optimization in terms- of AC response and settling performance. The evolution of the major poles and zeros of the gain- boosted OPAMP is

  4. 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.

  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. 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.

  7. Boosting Antimicrobial Peptides by Hydrophobic Oligopeptide End Tags*

    PubMed Central

    Schmidtchen, Artur; Pasupuleti, Mukesh; Mörgelin, Matthias; Davoudi, Mina; Alenfall, Jan; Chalupka, Anna; Malmsten, Martin

    2009-01-01

    A novel approach for boosting antimicrobial peptides through end tagging with hydrophobic oligopeptide stretches is demonstrated. Focusing on two peptides derived from kininogen, GKHKNKGKKNGKHNGWK (GKH17) and HKHGHGHGKHKNKGKKN (HKH17), tagging resulted in enhanced killing of Gram-positive Staphylococcus aureus, Gram-negative Escherichia coli, and fungal Candida albicans. Microbicidal potency increased with tag length, also in plasma, and was larger for Trp and Phe stretches than for aliphatic ones. The enhanced microbicidal effects correlated to a higher degree of bacterial wall rupture. Analogously, tagging promoted peptide binding to model phospholipid membranes and liposome rupture, particularly for anionic and cholesterol-void membranes. Tagged peptides displayed low toxicity, particularly in the presence of serum, and resisted degradation by human leukocyte elastase and by staphylococcal aureolysin and V8 proteinase. The biological relevance of these findings was demonstrated ex vivo and in vivo in porcine S. aureus skin infection models. The generality of end tagging for facile boosting of antimicrobial peptides without the need for post-synthesis modification was also demonstrated. PMID:19398550

  8. Playing tag with ANN: boosted top identification with pattern recognition

    NASA Astrophysics Data System (ADS)

    Almeida, Leandro G.; Backović, Mihailo; Cliche, Mathieu; Lee, Seung J.; Perelstein, Maxim

    2015-07-01

    Many searches for physics beyond the Standard Model at the Large Hadron Collider (LHC) rely on top tagging algorithms, which discriminate between boosted hadronic top quarks and the much more common jets initiated by light quarks and gluons. We note that the hadronic calorimeter (HCAL) effectively takes a "digital image" of each jet, with pixel intensities given by energy deposits in individual HCAL cells. Viewed in this way, top tagging becomes a canonical pattern recognition problem. With this motivation, we present a novel top tagging algorithm based on an Artificial Neural Network (ANN), one of the most popular approaches to pattern recognition. The ANN is trained on a large sample of boosted tops and light quark/gluon jets, and is then applied to independent test samples. The ANN tagger demonstrated excellent performance in a Monte Carlo study: for example, for jets with p T in the 1100-1200 GeV range, 60% top-tag efficiency can be achieved with a 4% mis-tag rate. We discuss the physical features of the jets identified by the ANN tagger as the most important for classification, as well as correlations between the ANN tagger and some of the familiar top-tagging observables and algorithms.

  9. 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.

  10. 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.

  11. Boosting color feature selection for color face recognition.

    PubMed

    Choi, Jae Young; Ro, Yong Man; Plataniotis, Konstantinos N

    2011-05-01

    This paper introduces the new color face recognition (FR) method that makes effective use of boosting learning as color-component feature selection framework. The proposed boosting color-component feature selection framework is designed for finding the best set of color-component features from various color spaces (or models), aiming to achieve the best FR performance for a given FR task. In addition, to facilitate the complementary effect of the selected color-component features for the purpose of color FR, they are combined using the proposed weighted feature fusion scheme. The effectiveness of our color FR method has been successfully evaluated on the following five public face databases (DBs): CMU-PIE, Color FERET, XM2VTSDB, SCface, and FRGC 2.0. Experimental results show that the results of the proposed method are impressively better than the results of other state-of-the-art color FR methods over different FR challenges including highly uncontrolled illumination, moderate pose variation, and small resolution face images.

  12. 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

  13. Feedback between motion and sensation provides nonlinear boost in run-and-tumble navigation

    PubMed Central

    Zucker, Steven W.

    2017-01-01

    Many organisms navigate gradients by alternating straight motions (runs) with random reorientations (tumbles), transiently suppressing tumbles whenever attractant signal increases. This induces a functional coupling between movement and sensation, since tumbling probability is controlled by the internal state of the organism which, in turn, depends on previous signal levels. Although a negative feedback tends to maintain this internal state close to adapted levels, positive feedback can arise when motion up the gradient reduces tumbling probability, further boosting drift up the gradient. Importantly, such positive feedback can drive large fluctuations in the internal state, complicating analytical approaches. Previous studies focused on what happens when the negative feedback dominates the dynamics. By contrast, we show here that there is a large portion of physiologically-relevant parameter space where the positive feedback can dominate, even when gradients are relatively shallow. We demonstrate how large transients emerge because of non-normal dynamics (non-orthogonal eigenvectors near a stable fixed point) inherent in the positive feedback, and further identify a fundamental nonlinearity that strongly amplifies their effect. Most importantly, this amplification is asymmetric, elongating runs in favorable directions and abbreviating others. The result is a “ratchet-like” gradient climbing behavior with drift speeds that can approach half the maximum run speed of the organism. Our results thus show that the classical drawback of run-and-tumble navigation—wasteful runs in the wrong direction—can be mitigated by exploiting the non-normal dynamics implicit in the run-and-tumble strategy. PMID:28264023

  14. Experimental verification of internal parameter in magnetically coupled boost used as PV optimizer in parallel association

    NASA Astrophysics Data System (ADS)

    Sawicki, Jean-Paul; Saint-Eve, Frédéric; Petit, Pierre; Aillerie, Michel

    2017-02-01

    This paper presents results of experiments aimed to verify a formula able to compute duty cycle in the case of pulse width modulation control for a DC-DC converter designed and realized in laboratory. This converter, called Magnetically Coupled Boost (MCB) is sized to step up only one photovoltaic module voltage to supply directly grid inverters. Duty cycle formula will be checked in a first time by identifying internal parameter, auto-transformer ratio, and in a second time by checking stability of operating point on the side of photovoltaic module. Thinking on nature of generator source and load connected to converter leads to imagine additional experiments to decide if auto-transformer ratio parameter could be used with fixed value or on the contrary with adaptive value. Effects of load variations on converter behavior or impact of possible shading on photovoltaic module are also mentioned, with aim to design robust control laws, in the case of parallel association, designed to compensate unwanted effects due to output voltage coupling.

  15. 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.

  16. 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

  17. Boosting oncolytic adenovirus potency with magnetic nanoparticles and magnetic force.

    PubMed

    Tresilwised, Nittaya; Pithayanukul, Pimolpan; Mykhaylyk, Olga; Holm, Per Sonne; Holzmüller, Regina; Anton, Martina; Thalhammer, Stefan; Adigüzel, Denis; Döblinger, Markus; Plank, Christian

    2010-08-02

    Oncolytic adenoviruses rank among the most promising innovative agents in cancer therapy. We examined the potential of boosting the efficacy of the oncolytic adenovirus dl520 by associating it with magnetic nanoparticles and magnetic-field-guided infection in multidrug-resistant (MDR) cancer cells in vitro and upon intratumoral injection in vivo. The virus was complexed by self-assembly with core-shell nanoparticles having a magnetite core of about 10 nm and stabilized by a shell containing 68 mass % lithium 3-[2-(perfluoroalkyl)ethylthio]propionate) and 32 mass % 25 kDa branched polyethylenimine. Optimized virus binding, sufficiently stable in 50% fetal calf serum, was found at nanoparticle-to-virus ratios of 5 fg of Fe per physical virus particle (VP) and above. As estimated from magnetophoretic mobility measurements, 3,600 to 4,500 magnetite nanocrystallites were associated per virus particle. Ultrastructural analysis by electron and atomic force microscopy showed structurally intact viruses surrounded by magnetic particles that occasionally bridged several virus particles. Viral uptake into cells at a given virus dose was enhanced 10-fold compared to nonmagnetic virus when infections were carried out under the influence of a magnetic field. Increased virus internalization resulted in a 10-fold enhancement of the oncolytic potency in terms of the dose required for killing 50% of the target cells (IC(50) value) and an enhancement of 4 orders of magnitude in virus progeny formation at equal input virus doses compared to nonmagnetic viruses. Furthermore, the full oncolytic effect developed within two days postinfection compared with six days in a nonmagnetic virus as a reference. Plotting target cell viability versus internalized virus particles for magnetic and nonmagnetic virus showed that the inherent oncolytic productivity of the virus remained unchanged upon association with magnetic nanoparticles. Hence, we conclude that the mechanism of boosting the

  18. 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)

  19. 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.

  20. 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.

  1. 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.

  2. 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).

  3. Link prediction boosted psychiatry disorder classification for functional connectivity network

    NASA Astrophysics Data System (ADS)

    Li, Weiwei; Mei, Xue; Wang, Hao; Zhou, Yu; Huang, Jiashuang

    2017-02-01

    Functional connectivity network (FCN) is an effective tool in psychiatry disorders classification, and represents cross-correlation of the regional blood oxygenation level dependent signal. However, FCN is often incomplete for suffering from missing and spurious edges. To accurate classify psychiatry disorders and health control with the incomplete FCN, we first `repair' the FCN with link prediction, and then exact the clustering coefficients as features to build a weak classifier for every FCN. Finally, we apply a boosting algorithm to combine these weak classifiers for improving classification accuracy. Our method tested by three datasets of psychiatry disorder, including Alzheimer's Disease, Schizophrenia and Attention Deficit Hyperactivity Disorder. The experimental results show our method not only significantly improves the classification accuracy, but also efficiently reconstructs the incomplete FCN.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  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. Aerodynamics of a turbojet-boosted launch vehicle concept

    NASA Technical Reports Server (NTRS)

    Small, W. J.; Riebe, G. D.; Taylor, A. H.

    1980-01-01

    Results from analytical and experimental studies of the aerodynamic characteristics of a turbojet-boosted launch vehicle are presented. The success of this launch vehicle concept depends upon several novel applications of aerodynamic technology, particularly in the area of takeoff lift and minimum transonic drag requirements. The take-off mode stresses leading edge vortex lift generated in parallel by a complex arrangement of low aspect ratio booster and orbiter wings. Wind-tunnel tests on a representative model showed that this low-speed lift is sensitive to geometric arrangements of the booster-orbiter combination and is not predictable by standard analytic techniques. Transonic drag was also experimentally observed to be very sensitive to booster location; however, these drag levels were accurately predicted by standard farfield wave drag theory.

  10. 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.

  11. Buck-Buck- Boost Regulatr (B3R)

    NASA Astrophysics Data System (ADS)

    Mourra, Olivier; Fernandez, Arturo; Landstroem, Sven; Tonicello, Ferdinando

    2011-10-01

    In a satellite, the main function of a Power Conditioning Unit (PCU) is to manage the energy coming from several power sources (usually solar arrays and battery) and to deliver it continuously to the users in an appropriate form during the overall mission. The objective of this paper is to present an electronic switching DC-DC converter called Buck-Buck-Boost Regulator (B3R) that could be used as a modular and recurrent solution in a PCU for regulated or un- regulated 28Vsatellite power bus classes. The power conversion stages of the B3R topology are first described. Then theoretical equations and practical tests illustrate how the converter operates in term of power conversion, control loops performances and efficiency. The paper finally provides some examples of single point failure tolerant implementation using the B3R.

  12. 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.

  13. 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.

  14. 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.

  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. Radiosurgical boost for primary high-grade gliomas.

    PubMed

    Prisco, Flavio E; Weltman, Eduardo; de Hanriot, Rodrigo M; Brandt, Reynaldo A

    2002-04-01

    The purpose of this study was to retrospectively evaluate the survival of patients with high-grade gliomas treated with external beam radiotherapy with or without radiosurgical boost. From July 1993 to April 1998, 32 patients were selected, 15 of which received radiosurgery. Inclusion criteria were age > 18 years, histological confirmation of high-grade glioma, primary tumor treatment with curative intent, unifocal tumor and supratentorial location. All patients were found to be in classes III-VI, according to the recursive partitioning analysis proposed by the Radiation Therapy Oncology Group. The median interval between radiotherapy and radiosurgery was 5 weeks (range 1-13). Treatment volumes ranged from 2.9 to 70.3 cc (median 15.0 cc). Prescribed radiosurgery doses varied from 8.0 to 12.5 Gy (median 10.0 Gy). Radiosurgery and control groups were well balanced with respect to prognostic factor distributions. Median actuarial survival time in radiosurgery and control groups was 21.4 months and 11.6 months, respectively (p = 0.0254). Among patients with KPS > 80, median survival time was 11.0 months and 53.9 months in the control and radiosurgery groups, respectively (p = 0.0103). Radiosurgery was the single factor correlated with survival on Cox model analysis (p = 0.0362) and was associated with a 2.76 relative reduction in the risk of cancer death (95% confidence interval (CI) 1.07-7.13). Our results suggest that radiosurgery may confer a survival advantage for patients in RPA classes III-VI, especially for those with Karnofsky performance status >80. The definitive role of radiosurgical boost for patients with high-grade gliomas awaits the results of randomized trials.

  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. Ductal Carcinoma in Situ-The Influence of the Radiotherapy Boost on Local Control

    SciTech Connect

    Wong, Philip; Lambert, Christine; Agnihotram, Ramanakumar V.; David, Marc; Duclos, Marie; Freeman, Carolyn R.

    2012-02-01

    Purpose: Local recurrence (LR) of ductal carcinoma in situ (DCIS) is reduced by whole-breast irradiation after breast-conserving surgery (BCS). However, the benefit of adding a radiotherapy boost to the surgical cavity for DCIS is unclear. We sought to determine the impact of the boost on LR in patients with DCIS treated at the McGill University Health Centre. Methods and Materials: A total of 220 consecutive cases of DCIS treated with BCS and radiotherapy between January 2000 and December 2006 were reviewed. Of the patients, 36% received a radiotherapy boost to the surgical cavity. Median follow-up was 46 months for the boost and no-boost groups. Kaplan-Meier survival analyses and Cox regression analyses were performed. Results: Compared with the no-boost group, patients in the boost group more frequently had positive and <0.1-cm margins (48% vs. 8%) (p < 0.0001) and more frequently were in higher-risk categories as defined by the Van Nuys Prognostic (VNP) index (p = 0.006). Despite being at higher risk for LR, none (0/79) of the patients who received a boost experienced LR, whereas 8 of 141 patients who did not receive a boost experienced an in-breast LR (log-rank p = 0.03). Univariate analysis of prognostic factors (age, tumor size, margin status, histological grade, necrosis, and VNP risk category) revealed only the presence of necrosis to significantly correlate with LR (log-rank p = 0.003). The whole-breast irradiation dose and fractionation schedule did not affect LR rate. Conclusions: Our results suggest that the use of a radiotherapy boost improves local control in DCIS and may outweigh the poor prognostic effect of necrosis.

  19. CyberKnife Boost for Patients with Cervical Cancer Unable to Undergo Brachytherapy.

    PubMed

    Haas, Jonathan Andrew; Witten, Matthew R; Clancey, Owen; Episcopia, Karen; Accordino, Diane; Chalas, Eva

    2012-01-01

    Standard radiation therapy for patients undergoing primary chemosensitized radiation for carcinomas of the cervix usually consists of external beam radiation followed by an intracavitary brachytherapy boost. On occasion, the brachytherapy boost cannot be performed due to unfavorable anatomy or because of coexisting medical conditions. We examined the safety and efficacy of using CyberKnife stereotactic body radiotherapy (SBRT) as a boost to the cervix after external beam radiation in those patients unable to have brachytherapy to give a more effective dose to the cervix than with conventional external beam radiation alone. Six consecutive patients with anatomic or medical conditions precluding a tandem and ovoid boost were treated with combined external beam radiation and CyberKnife boost to the cervix. Five patients received 45 Gy to the pelvis with serial intensity-modulated radiation therapy boost to the uterus and cervix to a dose of 61.2 Gy. These five patients received an SBRT boost to the cervix to a dose of 20 Gy in five fractions of 4 Gy each. One patient was treated to the pelvis to a dose of 45 Gy with an external beam boost to the uterus and cervix to a dose of 50.4 Gy. This patient received an SBRT boost to the cervix to a dose of 19.5 Gy in three fractions of 6.5 Gy. Five percent volumes of the bladder and rectum were kept to ≤75 Gy in all patients (i.e., V75 Gy ≤ 5%). All of the patients remain locally controlled with no evidence of disease following treatment. Grade 1 diarrhea occurred in 4/6 patients during the conventional external beam radiation. There has been no grade 3 or 4 rectal or bladder toxicity. There were no toxicities observed following SBRT boost. At a median follow-up of 14 months, CyberKnife radiosurgical boost is well tolerated and efficacious in providing a boost to patients with cervix cancer who are unable to undergo brachytherapy boost. Further follow-up is required to see if these results remain

  20. 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.

  1. Automatic detection of apical roots in oral radiographs

    NASA Astrophysics Data System (ADS)

    Wu, Yi; Xie, Fangfang; Yang, Jie; Cheng, Erkang; Megalooikonomou, Vasileios; Ling, Haibin

    2012-03-01

    The apical root regions play an important role in analysis and diagnosis of many oral diseases. Automatic detection of such regions is consequently the first step toward computer-aided diagnosis of these diseases. In this paper we propose an automatic method for periapical root region detection by using the state-of-theart machine learning approaches. Specifically, we have adapted the AdaBoost classifier for apical root detection. One challenge in the task is the lack of training cases especially for diseased ones. To handle this problem, we boost the training set by including more root regions that are close to the annotated ones and decompose the original images to randomly generate negative samples. Based on these training samples, the Adaboost algorithm in combination with Haar wavelets is utilized in this task to train an apical root detector. The learned detector usually generates a large amount of true and false positives. In order to reduce the number of false positives, a confidence score for each candidate detection result is calculated for further purification. We first merge the detected regions by combining tightly overlapped detected candidate regions and then we use the confidence scores from the Adaboost detector to eliminate the false positives. The proposed method is evaluated on a dataset containing 39 annotated digitized oral X-Ray images from 21 patients. The experimental results show that our approach can achieve promising detection accuracy.

  2. Modeling a multilevel boost converter using SiC components for PV application

    NASA Astrophysics Data System (ADS)

    Alateeq, Ayoob S.; Almalaq, Yasser A.; Matin, Mohammad A.

    2016-09-01

    This paper discusses a DC-DC multilevel boost with wide bandgap components for PV applications. In the PV system, the multilevel boost converter is advisable to be used over the conventional boost converter because of the high ratio conversion. The multilevel boost converter is designed with one inductor, 2N-1 silicon carbide (SiC) schottky diodes, 2N-1 capacitors and one SiC MOSFET where N is the number of levels. Inserting SiC components in the design helps to maintain the temperature effect that could cause a high power loss. Most function of using a multilevel boost converter is to produce a high output voltage without using either a power transformer or a coupled inductor. Achieving a high gain output in the multilevel boost converter depends on the level of the converter and the switching duty cycle. The demonstrated design is a multilevel boost converter supplies from 220 V to rate 2 KW power. The switching frequency is 100 KHz and the output voltage of 4-level is 3.5 KV. Several values of temperatures are applicable to the system and the effect of changing the temperature on efficiency is studied. The developed design is simulated by using a LTspice software and the results are discussed.

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

    PubMed Central

    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. PMID:22522322

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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

  11. Adaptation of adaptive optics systems.

    NASA Astrophysics Data System (ADS)

    Xin, Yu; Zhao, Dazun; Li, Chen

    1997-10-01

    In the paper, a concept of an adaptation of adaptive optical system (AAOS) is proposed. The AAOS has certain real time optimization ability against the variation of the brightness of detected objects m, atmospheric coherence length rO and atmospheric time constant τ by means of changing subaperture number and diameter, dynamic range, and system's temporal response. The necessity of AAOS using a Hartmann-Shack wavefront sensor and some technical approaches are discussed. Scheme and simulation of an AAOS with variable subaperture ability by use of both hardware and software are presented as an example of the system.

  12. 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.

  13. Boosting productivity: a framework for professional/amateur collaborative teamwork

    NASA Astrophysics Data System (ADS)

    Al-Shedhani, Saleh S.

    2002-11-01

    As technology advances, remote operation of telescopes has paved the way for joint observational projects between Astronomy clubs. Equipped with a small telescope, a standard CCD, and a networked computer, the observatory can be set up to carry out several photometric studies. However, most club members lack the basic training and background required for such tasks. A collaborative network between professionals and amateurs is proposed to utilize professional know-how and amateurs' readiness for continuous observations. Working as a team, various long-term observational projects can be carried out using small telescopes. Professionals can play an important role in raising the standards of astronomy clubs via specialized training programs for members on how to use the available technology to search/observe certain events (e.g. supernovae, comets, etc.). Professionals in return can accumulate a research-relevant database and can set up an early notification scheme based on comparative analyses of the recently-added images in an online archive. Here we present a framework for the above collaborative teamwork that uses web-based communication tools to establish remote/robotic operation of the telescope, and an online archive and discussion forum, to maximize the interactions between professionals and amateurs and to boost the productivity of small telescope observatories.

  14. 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.

  15. 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.

  16. 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.

  17. Boosting the performance of red PHOLEDs by exciton harvesting

    NASA Astrophysics Data System (ADS)

    Chang, Y.-L.; Wang, Z. B.; Helander, M. G.; Qiu, J.; Lu, Z. H.

    2012-09-01

    Significant development has been made on phosphorescent organic light emitting diodes (PHOLEDs) over the past decade, which eventually resulted in the commercialization of widely distributed active-matrix organic light emitting diode displays for mobile phones. However, higher efficiency PHOLEDs are still needed to further reduce the cost and lower the power consumption for general lighting and LED backlight applications. In particular, red PHOLEDs currently have in general the lowest efficiencies among the three primary colors, due most likely to the energy-gap law. Therefore, a number of groups have of made use of various device configurations, including insertion of a carrier blocking or exciton confining layer, doping the transport layers, as well as employing multiple emissive zone structures to improve the device efficiency. However, these approaches are rather inconvenient for commercial applications. In this work, we have developed a simpler way to boost the performance of red PHOLEDs by incorporating an exciton harvesting green emitter, which transfers a large portion of the energy to the co-deposited red emitter. A high external quantum efficiency (EQE) of 20.6% was achieved, which is among the best performances for red PHOLEDs.

  18. 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.

  19. Massage-like stroking boosts the immune system in mice

    PubMed Central

    Major, Benjamin; Rattazzi, Lorenza; Brod, Samuel; Pilipović, Ivan; Leposavić, Gordana; D’Acquisto, Fulvio

    2015-01-01

    Recent clinical evidence suggests that the therapeutic effect of massage involves the immune system and that this can be exploited as an adjunct therapy together with standard drug-based approaches. In this study, we investigated the mechanisms behind these effects exploring the immunomodulatory function of stroking as a surrogate of massage-like therapy in mice. C57/BL6 mice were stroked daily for 8 days either with a soft brush or directly with a gloved hand and then analysed for differences in their immune repertoire compared to control non-stroked mice. Our results show that hand- but not brush-stroked mice demonstrated a significant increase in thymic and splenic T cell number (p < 0.05; p < 0.01). These effects were not associated with significant changes in CD4/CD8 lineage commitment or activation profile. The boosting effects on T cell repertoire of massage-like therapy were associated with a decreased noradrenergic innervation of lymphoid organs and counteracted the immunosuppressive effect of hydrocortisone in vivo. Together our results in mice support the hypothesis that massage-like therapies might be of therapeutic value in the treatment of immunodeficiencies and related disorders and suggest a reduction of the inhibitory noradrenergic tone in lymphoid organs as one of the possible explanations for their immunomodulatory function. PMID:26046935

  20. Phasic boosting of auditory perception by visual emotion.

    PubMed

    Selinger, Lenka; Domínguez-Borràs, Judith; Escera, Carles

    2013-12-01

    Emotionally negative stimuli boost perceptual processes. There is little known, however, about the timing of this modulation. The present study aims at elucidating the phasic effects of, emotional processing on auditory processing within subsequent time-windows of visual emotional, processing in humans. We recorded the electroencephalogram (EEG) while participants responded to a, discrimination task of faces with neutral or fearful expressions. A brief complex tone, which subjects, were instructed to ignore, was displayed concomitantly, but with different asynchronies respective to, the image onset. Analyses of the N1 auditory event-related potential (ERP) revealed enhanced brain, responses in presence of fearful faces. Importantly, this effect occurred at picture-tone asynchronies of, 100 and 150ms, but not when these were displayed simultaneously, or at 50ms or 200ms asynchrony. These results confirm the existence of a fast-operating crossmodal effect of visual emotion on auditory, processing, suggesting a phasic variation according to the time-course of emotional processing.

  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. Sparse approximation through boosting for learning large scale kernel machines.

    PubMed

    Sun, Ping; Yao, Xin

    2010-06-01

    Recently, sparse approximation has become a preferred method for learning large scale kernel machines. This technique attempts to represent the solution with only a subset of original data points also known as basis vectors, which are usually chosen one by one with a forward selection procedure based on some selection criteria. The computational complexity of several resultant algorithms scales as O(NM(2)) in time and O(NM) in memory, where N is the number of training points and M is the number of basis vectors as well as the steps of forward selection. For some large scale data sets, to obtain a better solution, we are sometimes required to include more basis vectors, which means that M is not trivial in this situation. However, the limited computational resource (e.g., memory) prevents us from including too many vectors. To handle this dilemma, we propose to add an ensemble of basis vectors instead of only one at each forward step. The proposed method, closely related to gradient boosting, could decrease the required number M of forward steps significantly and thus a large fraction of computational cost is saved. Numerical experiments on three large scale regression tasks and a classification problem demonstrate the effectiveness of the proposed approach.

  3. Redundant Interdependencies Boost the Robustness of Multiplex Networks

    NASA Astrophysics Data System (ADS)

    Radicchi, Filippo; Bianconi, Ginestra

    2017-01-01

    In the analysis of the robustness of multiplex networks, it is commonly assumed that a node is functioning only if its interdependent nodes are simultaneously functioning. According to this model, a multiplex network becomes more and more fragile as the number of layers increases. In this respect, the addition of a new layer of interdependent nodes to a preexisting multiplex network will never improve its robustness. Whereas such a model seems appropriate to understand the effect of interdependencies in the simplest scenario of a network composed of only two layers, it may seem unsuitable to characterize the robustness of real systems formed by multiple network layers. In fact, it seems unrealistic that a real system evolved, through the development of multiple layers of interactions, towards a fragile structure. In this paper, we introduce a model of percolation where the condition that makes a node functional is that the node is functioning in at least two of the layers of the network. The model reduces to the commonly adopted percolation model for multiplex networks when the number of layers equals two. a larger number of layers, however, the model describes a scenario where the addition of new layers boosts the robustness of the system by creating redundant interdependencies among layers. We prove this fact thanks to the development of a message-passing theory that is able to characterize the model in both synthetic and real-world multiplex graphs.

  4. 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

  5. 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.

  6. Max-confidence boosting with uncertainty for visual tracking.

    PubMed

    Guo, Wen; Cao, Liangliang; Han, Tony X; Yan, Shuicheng; Xu, Changsheng

    2015-05-01

    The challenges in visual tracking call for a method which can reliably recognize the subject of interests in an environment, where the appearance of both the background and the foreground change with time. Many existing studies model this problem as tracking by classification with online updating of the classification models, however, most of them overlook the ambiguity in visual modeling and do not consider the prior information in the tracking process. In this paper, we present a novel visual tracking method called max-confidence boosting (MCB), which explores a new way of online updating ambiguous visual phenomenon. The MCB framework models uncertainty in prior knowledge utilizing the indeterministic labels, which are used in updating models from previous frames and the new frame. Our proposed MCB tracker allows ambiguity in the tracking process and can effectively alleviate the drift problem. Many experimental results in challenging video sequences verify the success of our method, and our MCB tracker outperforms a number of the state-of-the-art tracking by classification methods.

  7. 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.

  8. 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.

  9. Boosting forward-time population genetic simulators through genotype compression

    PubMed Central

    2013-01-01

    Background Forward-time population genetic simulations play a central role in deriving and testing evolutionary hypotheses. Such simulations may be data-intensive, depending on the settings to the various parameters controlling them. In particular, for certain settings, the data footprint may quickly exceed the memory of a single compute node. Results We develop a novel and general method for addressing the memory issue inherent in forward-time simulations by compressing and decompressing, in real-time, active and ancestral genotypes, while carefully accounting for the time overhead. We propose a general graph data structure for compressing the genotype space explored during a simulation run, along with efficient algorithms for constructing and updating compressed genotypes which support both mutation and recombination. We tested the performance of our method in very large-scale simulations. Results show that our method not only scales well, but that it also overcomes memory issues that would cripple existing tools. Conclusions As evolutionary analyses are being increasingly performed on genomes, pathways, and networks, particularly in the era of systems biology, scaling population genetic simulators to handle large-scale simulations is crucial. We believe our method offers a significant step in that direction. Further, the techniques we provide are generic and can be integrated with existing population genetic simulators to boost their performance in terms of memory usage. PMID:23763838

  10. Adaptive equalization

    NASA Astrophysics Data System (ADS)

    Qureshi, S. U. H.

    1985-09-01

    Theoretical work which has been effective in improving data transmission by telephone and radio links using adaptive equalization (AE) techniques is reviewed. AE has been applied to reducing the temporal dispersion effects, such as intersymbol interference, caused by the channel accessed. Attention is given to the Nyquist telegraph transmission theory, least mean square error adaptive filtering and the theory and structure of linear receive and transmit filters for reducing error. Optimum nonlinear receiver structures are discussed in terms of optimality criteria as a function of error probability. A suboptimum receiver structure is explored in the form of a decision-feedback equalizer. Consideration is also given to quadrature amplitude modulation and transversal equalization for receivers.

  11. 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.

  12. 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.

  13. 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.

  14. Industrial Assessment Center Helps Boost Efficiency for Small and Medium Manufacturers

    SciTech Connect

    Johnson, Mark; Friedman, David

    2016-12-15

    The Industrial Assessment Center program helps small and medium manufacturers boost efficiency and save energy. It pairs companies with universities as students perform energy assessments and provide recommendations to improve their facilities.

  15. Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations and Biological Condition

    EPA Science Inventory

    Boosted regression tree (BRT) models were developed to quantify the nonlinear relationships between landscape variables and nutrient concentrations in a mesoscale mixed land cover watershed during base-flow conditions. Factors that affect instream biological components, based on ...

  16. Hour-Long Nap May Boost Brain Function in Older Adults

    MedlinePlus

    ... fullstory_162923.html Hour-Long Nap May Boost Brain Function in Older Adults Linked to improved memory and ... during the day had any effects on their brain function. Nearly 60 percent of the people regularly napped ...

  17. Industrial Assessment Center Helps Boost Efficiency for Small and Medium Manufacturers

    ScienceCinema

    Johnson, Mark; Friedman, David

    2017-01-06

    The Industrial Assessment Center program helps small and medium manufacturers boost efficiency and save energy. It pairs companies with universities as students perform energy assessments and provide recommendations to improve their facilities.

  18. 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.

  19. 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.

  20. Smooth-Transition Simple Digital PWM Modulator for Four-Switch Buck-Boost Converters

    NASA Astrophysics Data System (ADS)

    Rodriguez, Alberto; Rodriguez, Miguel; Vazquez, Aitor; Maija, Pablo F.; Sebastian, Javier

    2014-08-01

    Four Switch non-inverting Buck-Boost (4SBB) converters are extensively used in non-isolated applications where voltage step-up and step-down are required. In order to achieve high efficiency operation it is preferred to control the 4SBB as a Buck or Boost converter, depending on the input/output voltage ratio. However, when input and output voltages are close this approach requires near- unity conversion ratios, which are difficult to achieve in practice. Several alternative operating modes have been proposed in the literature to overcome this issue. In particular, operating the 4SBB as a Buck and Boost at the same time (Buck+Boost mode) has proven to be adequate to achieve near-unity conversion ratios.This paper proposes a simple, hardware-efficient digital pulse width modulator for a 4SBB that enables operation in Buck, Boost and Buck+Boost modes, thus allowing near-unity conversion ratios, while achieving smooth transitions between the different modes. The proposed modulator is simulated with Simulink and experimentally demonstrated using a 500W 4SBB converter with 24V input voltage and 12V-36V output voltage range.

  1. Boosting infrared energy transfer in 3D nanoporous gold antennas.

    PubMed

    Garoli, D; Calandrini, E; Bozzola, A; Ortolani, M; Cattarin, S; Barison, S; Toma, A; De Angelis, F

    2017-01-05

    The applications of plasmonics to energy transfer from free-space radiation to molecules are currently limited to the visible region of the electromagnetic spectrum due to the intrinsic optical properties of bulk noble metals that support strong electromagnetic field confinement only close to their plasma frequency in the visible/ultraviolet range. In this work, we show that nanoporous gold can be exploited as a plasmonic material for the mid-infrared region to obtain strong electromagnetic field confinement, co-localized with target molecules into the nanopores and resonant with their vibrational frequency. The effective optical response of the nanoporous metal enables the penetration of optical fields deep into the nanopores, where molecules can be loaded thus achieving a more efficient light-matter coupling if compared to bulk gold. In order to realize plasmonic resonators made of nanoporous gold, we develop a nanofabrication method based on polymeric templates for metal deposition and we obtain antenna arrays resonating at mid-infrared wavelengths selected by design. We then coat the antennas with a thin (3 nm) silica layer acting as the target dielectric layer for optical energy transfer. We study the strength of the light-matter coupling at the vibrational absorption frequency of silica at 1240 cm(-1) through the analysis of the experimental Fano lineshape that is benchmarked against identical structures made of bulk gold. The boost in the optical energy transfer from free-space mid-infrared radiation to molecular vibrations in nanoporous 3D nanoantenna arrays can open new application routes for plasmon-enhanced physical-chemical reactions.

  2. 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.

  3. 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.

  4. A "Boosted Fireball" Model for Structured Relativistic Jets

    NASA Astrophysics Data System (ADS)

    Duffell, Paul C.; MacFadyen, Andrew I.

    2013-10-01

    We present a model for relativistic jets which generates a particular angular distribution of Lorentz factor and energy per solid angle. We consider a fireball with specific internal energy E/M launched with bulk Lorentz factor γ B . In its center-of-momentum frame the fireball expands isotropically, converting its internal energy into radially expanding flow with asymptotic Lorentz factor η0 ~ E/M. In the lab frame the flow is beamed, expanding with Lorentz factor Γ = 2η0γ B in the direction of its initial bulk motion and with characteristic opening angle θ0 ~ 1/γ B . The flow is jet-like with Γθ0 ~ 2η0 such that jets with Γ > 1/θ0 are naturally produced. The choice η0 ~ γ B ~ 10 yields a jet with Γ ~ 200 on-axis and angular structure characterized by opening angle θ0 ~ 0.1 of relevance for cosmological gamma-ray bursts (GRBs), while γ B >~ 1 may be relevant for low-luminosity GRBs. The model produces a family of outflows, of relevance for different relativistic phenomena with structures completely determined by η0 and γ B . We calculate the energy per unit solid angle for the model and use it to compute light curves for comparison with the widely used top-hat model. The jet break in the boosted fireball light curve is greatly subdued when compared to the top-hat model because the edge of the jet is smoother than for a top-hat. This may explain missing jet breaks in afterglow light curves.

  5. 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.

  6. Heterologous prime-boost-boost immunisation of Chinese cynomolgus macaques using DNA and recombinant poxvirus vectors expressing HIV-1 virus-like particles

    PubMed Central

    2011-01-01

    Background There is renewed interest in the development of poxvirus vector-based HIV vaccines due to the protective effect observed with repeated recombinant canarypox priming with gp120 boosting in the recent Thai placebo-controlled trial. This study sought to investigate whether a heterologous prime-boost-boost vaccine regimen in Chinese cynomolgus macaques with a DNA vaccine and recombinant poxviral vectors expressing HIV virus-like particles bearing envelopes derived from the most prevalent clades circulating in sub-Saharan Africa, focused the antibody response to shared neutralising epitopes. Methods Three Chinese cynomolgus macaques were immunised via intramuscular injections using a regimen composed of a prime with two DNA vaccines expressing clade A Env/clade B Gag followed by boosting with recombinant fowlpox virus expressing HIV-1 clade D Gag, Env and cholera toxin B subunit followed by the final boost with recombinant modified vaccinia virus Ankara expressing HIV-1 clade C Env, Gag and human complement protein C3d. We measured the macaque serum antibody responses by ELISA, enumerated T cell responses by IFN-γ ELISpot and assessed seroneutralisation of HIV-1 using the TZM-bl β-galactosidase assay with primary isolates of HIV-1. Results This study shows that large and complex synthetic DNA sequences can be successfully cloned in a single step into two poxvirus vectors: MVA and FPV and the recombinant poxviruses could be grown to high titres. The vaccine candidates showed appropriate expression of recombinant proteins with the formation of authentic HIV virus-like particles seen on transmission electron microscopy. In addition the b12 epitope was shown to be held in common by the vaccine candidates using confocal immunofluorescent microscopy. The vaccine candidates were safely administered to Chinese cynomolgus macaques which elicited modest T cell responses at the end of the study but only one out of the three macaques elicited an HIV-specific antibody

  7. Protection Against Dengue Virus by Non-Replicating and Live Attenuated Vaccines Used Together in a Prime Boost Vaccination Strategy

    DTIC Science & Technology

    2010-01-01

    Protection against dengue virus by non-replicating and live attenuated vaccines used together in a prime boost vaccination strategy Monika Simmons a...Dengue DNA Punfied inacdvared virus Uvc artenuatcd virus Jlnmc boost A new vaccination strategy for dengue virus (DENV) was eval uated in rhesus...region (TDNA) then boosting 2 months l,ltcr with a tetravalent live aucnuated virus (TLAV) vaccine . Both vaccine combinations elicited virus

  8. 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.

  9. 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.

  10. Asymptotically flat radiative space-times with boost-rotation symmetry: The general structure

    SciTech Connect

    Biicak, J.; Schmidt, B. )

    1989-09-15

    This paper deals for the first time with boost-rotation-symmetric space-times from a unified point of view. Boost-rotation-symmetric space-times are the only explicitly known exact solutions of the Einstein vacuum field equations which describe moving singularities or black holes, are radiative and asymptotically flat in the sense that they admit global, though not complete, smooth null infinity, as well as spacelike and timelike infinities. They very likely represent the exterior fields of uniformly accelerated sources in general relativity and may serve as tests of various approximation methods, as nontrivial illustrations of the theory of the asymptotic structure of radiative space-times, and as test beds in numerical relativity. Examples are the {ital C}-metric or the solutions of Bonnor and Swaminarayan. The space-times are defined in a geometrical manner and their global properties are studied in detail, in particular their asymptotic structure. It is demonstrated how one can construct any asymptotically flat boost-rotation-symmetric space-time starting from the boost-rotation-symmetric solution of the flat-space wave equation. The problem of uniformly accelerated sources in special relativity is also discussed. The radiative properties and specific examples of the boost-rotation-symmetric space-times will be analyzed in a following paper.

  11. 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

  12. 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.

  13. Boosting support vector regression in QSAR studies of bioactivities of chemical compounds.

    PubMed

    Zhou, Yan-Ping; Jiang, Jian-Hui; Lin, Wei-Qi; Zou, Hong-Yan; Wu, Hai-Long; Shen, Guo-Li; Yu, Ru-Qin

    2006-07-01

    In this paper, boosting has been coupled with SVR to develop a new method, boosting support vector regression (BSVR). BSVR is implemented by firstly constructing a series of SVR models on the various weighted versions of the original training set and then combining the predictions from the constructed SVR models to obtain integrative results by weighted median. The proposed BSVR algorithm has been used to predict toxicities of nitrobenzenes and inhibitory potency of 1-phenyl[2H]-tetrahydro-triazine-3-one analogues as inhibitors of 5-lipoxygenase. As comparisons to this method, the multiple linear regression (MLR) and conventional support vector regression (SVR) have also been investigated. Experimental results have shown that the introduction of boosting drastically enhances the generalization performance of individual SVR model and BSVR is a well-performing technique in QSAR studies superior to multiple linear regression.

  14. Improved anamnestic response among adolescents boosted with a higher dose of the hepatitis B vaccine.

    PubMed

    Chaves, Sandra S; Groeger, Justina; Helgenberger, Louisa; Auerbach, Steven B; Bialek, Stephanie R; Hu, Dale J; Drobeniuc, Jan

    2010-04-01

    Some hepatitis B vaccine booster studies have suggested waning of vaccine-induced immunity in adolescents vaccinated starting at birth. Those studies, however, used a pediatric formulation of the hepatitis B vaccine as a booster to detect anamnestic response. We compared adolescents boosted with an adult dose of hepatitis B vaccine with those boosted with a pediatric dose. Among adolescents who had lost protective antibody levels against hepatitis B, a higher proportion had an anamnestic response when boosted with the adult dose (60.0% vs. 43.8%). Thus, higher antigen concentrations may be required to elicit an adequate immune memory response. Despite improved anamnestic response, our study still raises concerns about whether children immunized in early infancy will remain protected from hepatitis B as they age into adulthood.

  15. 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.

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

    PubMed

    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.

  17. On Asymmetric Classifier Training for Detector Cascades

    SciTech Connect

    Gee, Timothy Felix

    2006-01-01

    This paper examines the Asymmetric AdaBoost algorithm introduced by Viola and Jones for cascaded face detection. The Viola and Jones face detector uses cascaded classifiers to successively filter, or reject, non-faces. In this approach most non-faces are easily rejected by the earlier classifiers in the cascade, thus reducing the overall number of computations. This requires earlier cascade classifiers to very seldomly reject true instances of faces. To reflect this training goal, Viola and Jones introduce a weighting parameter for AdaBoost iterations and show it enforces a desirable bound. During their implementation, a modification to the proposed weighting was introduced, while enforcing the same bound. The goal of this paper is to examine their asymmetric weighting by putting AdaBoost in the form of Additive Regression as was done by Friedman, Hastie, and Tibshirani. The author believes this helps to explain the approach and adds another connection between AdaBoost and Additive Regression.

  18. Dendritic Cell Targeting Effectively Boosts T Cell Responses Elicited by an HIV Multiepitope DNA Vaccine.

    PubMed

    Apostólico, Juliana de Souza; Lunardelli, Victória Alves Santos; Yamamoto, Marcio Massao; Souza, Higo Fernando Santos; Cunha-Neto, Edecio; Boscardin, Silvia Beatriz; Rosa, Daniela Santoro

    2017-01-01

    Despite several efforts in the last decades, an efficacious HIV-1 vaccine is still not available. Different approaches have been evaluated, such as recombinant proteins, viral vectors, DNA vaccines, and, most recently, dendritic cell (DC) targeting. This strategy is based on DC features that place them as central for induction of immunity. Targeting is accomplished by the use of chimeric monoclonal antibodies directed to DC surface receptors fused to the antigen of interest. In this work, we targeted eight promiscuous HIV-derived CD4(+) T cell epitopes (HIVBr8) to the DEC205(+) DCs by fusing the multiepitope immunogen to the heavy chain of αDEC205 (αDECHIVBr8), in the presence of the TLR3 agonist poly (I:C). In addition, we tested a DNA vaccine encoding the same epitopes using homologous or heterologous prime-boost regimens. Our results showed that mice immunized with αDECHIVBr8 presented higher CD4(+) and CD8(+) T cell responses when compared to mice that received the DNA vaccine (pVAXHIVBr8). In addition, pVAXHIVBr8 priming followed by αDECHIVBr8 boosting induced higher polyfunctional proliferative and cytokine-producing T cell responses to HIV-1 peptides than homologous DNA immunization or heterologous αDEC prime/DNA boost. Based on these results, we conclude that homologous prime-boost and heterologous boosting immunization strategies targeting CD4(+) epitopes to DCs are effective to improve HIV-specific cellular immune responses when compared to standalone DNA immunization. Moreover, our results indicate that antigen targeting to DC is an efficient strategy to boost immunity against a multiepitope immunogen, especially in the context of DNA vaccination.

  19. 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.

  20. 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.

  1. Planning the Breast Boost: Comparison of Three Techniques and Evolution of Tumor Bed During Treatment

    SciTech Connect

    Hepel, Jaroslaw T. Evans, Suzanne B.; Hiatt, Jessica R.; Price, Lori Lyn; DiPetrillo, Thomas; Wazer, David E.; MacAusland, Stephanie G.

    2009-06-01

    Purpose: To evaluate the accuracy of two clinical techniques for electron boost planning compared with computed tomography (CT)-based planning. Additionally, we evaluated the tumor bed characteristics at whole breast planning and boost planning. Methods and Materials: A total of 30 women underwent tumor bed boost planning within 2 weeks of completing whole breast radiotherapy using three planning techniques: scar-based planning, palpation/clinical-based planning, and CT-based planning. The plans were analyzed for dosimetric coverage of the CT-delineated tumor bed. The cavity visualization score was used to define the CT-delineated tumor bed as well or poorly defined. Results: Scar-based planning resulted in inferior tumor bed coverage compared with CT-based planning, with the minimal dose received by 90% of the target volume >90% in 53% and a geographic miss in 53%. The results of palpation/clinical-based planning were significantly better: 87% and 10% for the minimal dose received by 90% of the target volume >90% and geographic miss, respectively. Of the 30 tumor beds, 16 were poorly defined by the cavity visualization score. Of these 16, 8 were well demarcated by the surgical clips. The evaluation of the 22 well-defined tumor beds revealed similar results. A comparison of the tumor bed volume from the initial planning CT scan to the boost planning CT scan revealed a decrease in size in 77% of cases. The mean decrease in volume was 52%. Conclusion: The results of our study have shown that CT-based planning allows for optimal tumor bed coverage compared with clinical and scar-based approaches. However, in the setting of a poorly visualized cavity on CT without surgical clips, palpation/clinical-based planning can help delineate the appropriate target volumes and is superior to scar-based planning. CT simulation at boost planning could allow for a reduction in the boost volumes.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Dendritic Cell Targeting Effectively Boosts T Cell Responses Elicited by an HIV Multiepitope DNA Vaccine

    PubMed Central

    Apostólico, Juliana de Souza; Lunardelli, Victória Alves Santos; Yamamoto, Marcio Massao; Souza, Higo Fernando Santos; Cunha-Neto, Edecio; Boscardin, Silvia Beatriz; Rosa, Daniela Santoro

    2017-01-01

    Despite several efforts in the last decades, an efficacious HIV-1 vaccine is still not available. Different approaches have been evaluated, such as recombinant proteins, viral vectors, DNA vaccines, and, most recently, dendritic cell (DC) targeting. This strategy is based on DC features that place them as central for induction of immunity. Targeting is accomplished by the use of chimeric monoclonal antibodies directed to DC surface receptors fused to the antigen of interest. In this work, we targeted eight promiscuous HIV-derived CD4+ T cell epitopes (HIVBr8) to the DEC205+ DCs by fusing the multiepitope immunogen to the heavy chain of αDEC205 (αDECHIVBr8), in the presence of the TLR3 agonist poly (I:C). In addition, we tested a DNA vaccine encoding the same epitopes using homologous or heterologous prime-boost regimens. Our results showed that mice immunized with αDECHIVBr8 presented higher CD4+ and CD8+ T cell responses when compared to mice that received the DNA vaccine (pVAXHIVBr8). In addition, pVAXHIVBr8 priming followed by αDECHIVBr8 boosting induced higher polyfunctional proliferative and cytokine-producing T cell responses to HIV-1 peptides than homologous DNA immunization or heterologous αDEC prime/DNA boost. Based on these results, we conclude that homologous prime-boost and heterologous boosting immunization strategies targeting CD4+ epitopes to DCs are effective to improve HIV-specific cellular immune responses when compared to standalone DNA immunization. Moreover, our results indicate that antigen targeting to DC is an efficient strategy to boost immunity against a multiepitope immunogen, especially in the context of DNA vaccination. PMID:28223987

  7. SU-E-T-210: Comparison of Proton with Electron Boost in Breast Cancer Treatment

    SciTech Connect

    Zheng, Y; Chang, A; Liu, Y

    2015-06-15

    Purpose: Electron beams are commonly used for boost radiation following whole breast irradiation (WBI) to improve the in-breast local control. Proton beams have a finite range and a sharper distal dose falloff compared to electron beams, thus potentially sparing more heart and lung in breast treatment. The purpose of the study is to compare protons with electrons for boost breast treatment in terms of target coverage and normal tissue sparing. Methods: Six breast cancer patients were included in this study. All women received WBI to 45–50 Gy, followed by a 10–16.2 Gy boost with standard fractionation. If proton beams were used for the boost treatment, an electron plan was retrospectively generated for comparison using the same CT set and structures, and vice versa if electron beams were used for treatment. Proton plans were generated using the treatment planning system (TPS) with two to three uniform scanning proton beams. Electron plans were generated using the Pinnacle TPS with one single en face beam. Dose-volume histograms (DVH) were calculated and compared between proton and electron boost plans. Results: Proton plans show a similar boost target coverage, similar skin dose, and much better heart and lung sparing. For an example patient, V95% for PTV was 99.98% and skin (5 mm shell) received a max dose close to the prescription dose for both protons and electrons; however, V2 and V5 for the ipsilateral lung and heart were 37.5%, 17.9% and 19.9%, 4.9% respectively for electrons, but were essentially 0 for protons. Conclusions: This dosimetric comparison demonstrates that while both proton therapy and electron therapy provided similar coverage and skin dose, proton therapy could largely reduce the dose to lung and heart, thus leading to potential less side effects.

  8. 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

  9. Performance comparison of pre-, boost-, and inline-multimode erbium-doped fiber amplifier configurations to boost mode-division multiplexed multimode fiber link

    NASA Astrophysics Data System (ADS)

    Gupta, Rajan; Kaler, Rajinder Singh

    2016-05-01

    The performance of 3×3, 4×4, 5×5, and 6×6 optical multi-input multioutput (MIMO) mode-division multiplexed multimode fiber (MMF) systems has been investigated using pre-, boost-, and inline-multimode erbium-doped fiber amplifier configuration methods with LPlm (linearly polarized) modes. The outcome of these configurations has been compared in terms of quality factor (Q-factor) and bit error rate (BER). It is reported that inline-configuration provides best results for all MIMO mode-division multiplexing (MDM) systems covering transmission distance of 100 km with acceptable BER (<10-9) and Q-factor (>10 dB) over MMF link to boost performance of MDM system.

  10. 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.

  11. Heterologous prime-boost vaccinations for poverty-related diseases: advantages and future prospects.

    PubMed

    Radosević, Katarina; Rodriguez, Ariane; Lemckert, Angelique; Goudsmit, Jaap

    2009-05-01

    Classical vaccination approaches, based on a single vaccine administered in a homologous prime-boost schedule and optimized to induce primarily neutralizing antibodies, are unlikely to be sufficiently efficacious to prevent TB, malaria or HIV infections. Novel vaccines, capable of inducing a more powerful immune response, in particular T-cell immunity, are desperately needed. Combining different vaccine modalities that are able to complement each other and induce broad and sustainable immunity is a promising approach. This review provides an overview of heterologous prime-boost vaccination modalities currently in development for the 'big three' poverty-related diseases and emphasizes the need for innovative vaccination approaches.

  12. Research on motion model for the hypersonic boost-glide aircraft

    NASA Astrophysics Data System (ADS)

    Xu, Shenda; Wu, Jing; Wang, Xueying

    2015-11-01

    A motion model for the hypersonic boost-glide aircraft(HBG) was proposed in this paper, which also analyzed the precision of model through simulation. Firstly the trajectory of HBG was analyzed, and a scheme which divide the trajectory into two parts then build the motion model on each part. Secondly a restrained model of boosting stage and a restrained model of J2 perturbation were established, and set up the observe model. Finally the analysis of simulation results show the feasible and high-accuracy of the model, and raise a expectation for intensive research.

  13. 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

  14. 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

  15. 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.

  16. 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

  17. Blocking Junctional Adhesion Molecule C Enhances Dendritic Cell Migration and Boosts the Immune Responses against Leishmania major

    PubMed Central

    Ballet, Romain; Emre, Yalin; Jemelin, Stéphane; Charmoy, Mélanie; Tacchini-Cottier, Fabienne; Imhof, Beat A.

    2014-01-01

    The recruitment of dendritic cells to sites of infections and their migration to lymph nodes is fundamental for antigen processing and presentation to T cells. In the present study, we showed that antibody blockade of junctional adhesion molecule C (JAM-C) on endothelial cells removed JAM-C away from junctions and increased vascular permeability after L. major infection. This has multiple consequences on the output of the immune response. In resistant C57BL/6 and susceptible BALB/c mice, we found higher numbers of innate immune cells migrating from blood to the site of infection. The subsequent migration of dendritic cells (DCs) from the skin to the draining lymph node was also improved, thereby boosting the induction of the adaptive immune response. In C57BL/6 mice, JAM-C blockade after L. major injection led to an enhanced IFN-γ dominated T helper 1 (Th1) response with reduced skin lesions and parasite burden. Conversely, anti JAM-C treatment increased the IL-4-driven T helper 2 (Th2) response in BALB/c mice with disease exacerbation. Overall, our results show that JAM-C blockade can finely-tune the innate cell migration and accelerate the consequent immune response to L. major without changing the type of the T helper cell response. PMID:25474593

  18. 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

  19. 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.

  20. Recombinant BCG prime and PPE protein boost provides potent protection against acute Mycobacterium tuberculosis infection in mice.

    PubMed

    Yang, Enzhuo; Gu, Jin; Wang, Feifei; Wang, Honghai; Shen, Hongbo; Chen, Zheng W

    2016-04-01

    Since BCG, the only vaccine widely used against tuberculosis (TB) in the world, provides varied protective efficacy and may not be effective for inducing long-term cellular immunity, it is in an urgent need to develop more effective vaccines and more potent immune strategies against TB. Prime-boost is proven to be a good strategy by inducing long-term protection. In this study, we tested the protective effect against Mycobacterium tuberculosis (Mtb) challenge of prime-boost strategy by recombinant BCG (rBCG) expressing PPE protein Rv3425 fused with Ag85B and Rv3425. Results showed that the prime-boost strategy could significantly increase the protective efficiency against Mtb infection, characterized by reduction of bacterial load in lung and spleen, attenuation of tuberculosis lesions in lung tissues. Importantly, we found that Rv3425 boost, superior to Ag85B boost, provided better protection against Mtb infection. Further research proved that rBCG prime-Rv3425 boost could obviously increase the expansion of lymphocytes, significantly induce IL-2 production by lymphocytes upon PPD stimulation, and inhibit IL-6 production at an early stage. It implied that rBCG prime-Rv3425 boost opted to induce Th1 immune response and provided a long-term protection against TB. These results implicated that rBCG prime-Rv3425 boost is a potent and promising strategy to prevent acute Mtb infection.

  1. 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…

  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. UCLA at TREC 2014 Clinical Decision Support Track: Exploring Language Models, Query Expansion, and Boosting

    DTIC Science & Technology

    2014-11-01

    for 6 months. Median performance for this topic was relatively low, despite being an easy diagnosis of hypothyroidism for a medical expert. However... hypothyroidism was ranked 3rd in the retrieval results. Without boosting, the highest-ranked article on hypothyroidism was ranked 16th. In contrast, this

  4. 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…

  5. 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.

  6. Detecting boosted dark matter from the Sun with large volume neutrino detectors

    SciTech Connect

    Berger, Joshua; Cui, Yanou; Zhao, Yue E-mail: ycui@perimeterinstitute.ca

    2015-02-01

    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.

  7. Stable boosted-frame simulations of laser-wakefield acceleration using Galilean coordinates

    NASA Astrophysics Data System (ADS)

    Lehe, Remi; Kirchen, Manuel; Godfrey, Brendan; Maier, Andreas; Vay, Jean-Luc

    2016-10-01

    While Particle-In-Cell (PIC) simulations of laser-wakefield acceleration are typically very computationally expensive, it is well-known that representing the system in a well-chosen Lorentz frame can reduce the computational cost by orders of magnitude. One of the limitation of this ``boosted-frame'' technique is the Numerical Cherenkov Instability (NCI) - a numerical instability that rapidly grows in the boosted frame and must be eliminated in order to obtain valid physical results. Several methods have been proposed in order to eliminate the NCI, but they introduce additional numerical corrections (e.g. heavy smoothing, unphysical modification of the dispersion relation, etc.) which could potentially alter the physics. By contrast, here we show that, for boosted-frame simulations of laser-wakefield acceleration, the NCI can be eliminated simply by integrating the PIC equations in Galilean coordinates (a.k.a comoving coordinates), without additional numerical correction. Using this technique, we show excellent agreement between simulations in the laboratory frame and Lorentz-boosted frame, with more than 2 orders of magnitude speedup in the latter case. Work supported by US-DOE Contracts DE-AC02-05CH11231.

  8. 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.

  9. Program aims to leverage the skills of community pharmacists to boost diabetes care.

    PubMed

    2007-06-01

    Community pharmacists take center stage in new effort to boost care of diabetes. That is the approach behind The American Pharmacists Association Foundation's Diabetes Ten City Challenge. The organization is trying to show that results from the much-heralded Asheville Project can be replicated in other regions as well.

  10. Responsivity boosting in FIR TiN LEKIDs using phonon recycling: simulations and array design

    NASA Astrophysics Data System (ADS)

    Fyhrie, Adalyn; McKenney, Christopher; Glenn, Jason; LeDuc, Henry G.; Gao, Jiansong; Day, Peter; Zmuidzinas, Jonas

    2016-07-01

    To characterize further the cosmic star formation history at high redshifts, a large-area survey by a cryogenic 4-6 meter class telescope with a focal plane populated by tens of thousands of far-infrared (FIR, 30-300 μm) detectors with broadband detector noise equivalent powers (NEPs) on the order of 3×10-9 W/√ Hz is needed. Ideal detectors for such a surveyor do not yet exist. As a demonstration of one technique for approaching the ultra-low NEPs required by this surveyor, we present the design of an array of 96 350 µm KIDs that utilize phonon recycling to boost responsivity. Our KID array is fabricated with TiN deposited on a silicon-on-insulator (SOI) wafer, which is a 2 μm thick layer of silicon bonded to a thicker slab of silicon by a thin oxide layer. The backside thick slab is etched away underneath the absorbers so that the inductors are suspended on just the 2 μm membrane. The intent is that quasiparticle recombination phonons are trapped in the thin membrane, thereby increasing their likelihood of being re-absorbed by the KID to break additional Cooper pairs and boost responsivity. We also present a Monte-Carlo simulation that predicts the amount of signal boost expected from phonon recycling given different detector geometries and illumination strategies. For our current array geometry, the simulation predicts a measurable 50% boost in responsivity.

  11. 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…

  12. 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.

  13. 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.…

  14. Five year outcomes of hypofractionated simultaneous integrated boost irradiation in breast conserving therapy; patterns of recurrence.

    PubMed

    Bantema-Joppe, Enja J; Vredeveld, Eline J; de Bock, Geertruida H; Busz, Dianne M; Woltman-van Iersel, Marleen; Dolsma, Wil V; van der Laan, Hans Paul; Langendijk, Johannes A; Maduro, John H

    2013-08-01

    In 2005, we introduced hypofractionated 3-dimensional conformal radiotherapy with a simultaneous integrated boost (3D-CRT-SIB) technique after breast conserving surgery. In a consecutive series of 752 consecutive female invasive breast cancer patients (stages I-III) the 5-year actuarial rate for local control was 98.9%. This new technique gives excellent 5-year local control.

  15. 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…

  16. Ontogeny of Adaptive Antibody Response to a Model Antigen in Captive Altricial Zebra Finches

    PubMed Central

    Killpack, Tess L.; Karasov, William H.

    2012-01-01

    Based on studies from the poultry literature, all birds are hypothesized to require at least 4 weeks to develop circulating mature B-cell lineages that express functionally different immunoglobulin specificities. However, many altricial passerines fledge at adult size less than four weeks after the start of embryonic development, and therefore may experience a period of susceptibility during the nestling and post-fledging periods. We present the first study, to our knowledge, to detail the age-related changes in adaptive antibody response in an altricial passerine. Using repeated vaccinations with non-infectious keyhole limpet hemocyanin (KLH) antigen, we studied the ontogeny of specific adaptive immune response in altricial zebra finches Taeniopygia guttata. Nestling zebra finches were first injected at 7 days (7d), 14 days (14d), or 21 days post-hatch (21d) with KLH-adjuvant emulsions, and boosted 7 days later. Adults were vaccinated in the same manner. Induced KLH-specific IgY antibodies were measured using ELISA. Comparisons within age groups revealed no significant increase in KLH-specific antibody levels between vaccination and boost in 7d birds, yet significant increases between vaccination and boost were observed in 14d, 21d, and adult groups. There was no significant difference among age groups in KLH antibody response to priming vaccination, yet KLH antibody response post-boost significantly increased with age among groups. Post-boost antibody response in all nestling age groups was significantly lower than in adults, indicating that mature adult secondary antibody response level was not achieved in zebra finches prior to fledging (21 days post-hatch in zebra finches). Findings from this study contribute fundamental knowledge to the fields of developmental immunology and ecological immunology and strengthen the utility of zebra finches as a model organism for future studies of immune ontogeny. PMID:23056621

  17. 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.

  18. Adaptive Image Denoising by Mixture Adaptation.

    PubMed

    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. The 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.

  19. 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

  20. Prostate stereotactic body radiotherapy with simultaneous integrated boost: which is the best planning method?

    PubMed Central

    2013-01-01

    Background The delivery of a simultaneous integrated boost to the intra-prostatic tumour nodule may improve local control. The ability to deliver such treatments with hypofractionated SBRT was attempted using RapidArc (Varian Medical systems, Palo Alto, CA) and Multiplan (Accuray inc, Sunnyvale, CA). Materials and methods 15 patients with dominant prostate nodules had RapidArc and Multiplan plans created using a 5 mm isotropic margin, except 3 mm posteriorly, aiming to deliver 47.5 Gy in 5 fractions to the boost whilst treating the whole prostate to 36.25 Gy in 5 fractions. An additional RapidArc plan was created using an 8 mm isotropic margin, except 5 mm posteriorly, to account for lack of intrafraction tracking. Results Both RapidArc and Multiplan can produce clinically acceptable boost plans to a dose of 47.5 Gy in 5 fractions. The mean rectal doses were lower for RapidArc plans (D50 13.2 Gy vs 15.5 Gy) but the number of missed constraints was the same for both planning methods (11/75). When the margin was increased to 8 mm/5 mm for the RapidArc plans to account for intrafraction motion, 37/75 constraints were missed. Conclusions RapidArc and Multiplan can produce clinically acceptable simultaneous integrated boost plans, but the mean rectal D50 and D20 with RapidArc are lower. If the margins are increased to account for intrafraction motion, the RapidArc plans exceed at least one dose constraint in 13/15 cases. Delivering a simultaneous boost with hypofractionation appears feasible, but requires small margins needing intrafraction motion tracking. PMID:24088319

  1. 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.

  2. Presentation of antigen in immune complexes is boosted by soluble bacterial immunoglobulin binding proteins.

    PubMed

    Léonetti, M; Galon, J; Thai, R; Sautès-Fridman, C; Moine, G; Ménez, A

    1999-04-19

    Using a snake toxin as a proteic antigen (Ag), two murine toxin-specific monoclonal antibodies (mAbs), splenocytes, and two murine Ag-specific T cell hybridomas, we showed that soluble protein A (SpA) from Staphylococcus aureus and protein G from Streptococcus subspecies, two Ig binding proteins (IBPs), not only abolish the capacity of the mAbs to decrease Ag presentation but also increase Ag presentation 20-100-fold. Five lines of evidence suggest that this phenomenon results from binding of an IBP-Ab-Ag complex to B cells possessing IBP receptors. First, we showed that SpA is likely to boost presentation of a free mAb, suggesting that the IBP-boosted presentation of an Ag in an immune complex results from the binding of IBP to the mAb. Second, FACS analyses showed that an Ag-Ab complex is preferentially targeted by SpA to a subpopulation of splenocytes mainly composed of B cells. Third, SpA-dependent boosted presentation of an Ag-Ab complex is further enhanced when splenocytes are enriched in cells containing SpA receptors. Fourth, the boosting effect largely diminishes when splenocytes are depleted of cells containing SpA receptors. Fifth, the boosting effect occurs only when IBP simultaneously contains a Fab and an Fc binding site. Altogether, our data suggest that soluble IBPs can bridge immune complexes to APCs containing IBP receptors, raising the possibility that during an infection process by bacteria secreting these IBPs, Ag-specific T cells may activate IBP receptor-containing B cells by a mechanism of intermolecular help, thus leading to a nonspecific immune response.

  3. 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.

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

    PubMed Central

    Turley, Jessica; Claridge Mackonis, Elizabeth

    2015-01-01

    Introduction 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. Methods 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. Results 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. Conclusion 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. PMID:26451242

  5. Radiotherapy Boost for the Dominant Intraprostatic Cancer Lesion-A Systematic Review and Meta-Analysis.

    PubMed

    von Eyben, Finn Edler; Kiljunen, Timo; Kangasmaki, Aki; Kairemo, Kalevi; von Eyben, Rie; Joensuu, Timo

    2016-06-01

    External beam radiotherapy (EBRT) for prostate cancer can be performed with a high dose of 86 Gy; however, one-tenth or more of the patients will develop recurrence. Prostate cancer is mainly multifocal, but a dominant intraprostatic lesion (DIL) is often the site of local recurrence after EBRT. We undertook a systematic review and meta-analysis to clarify whether functional imaging might identify the DIL and whether a RT boost to the DIL might be increased to an ultrahigh dose level of ≥ 90 Gy without increased toxicity. Of 62 selected studies, 13 reported the size of the DIL. The mean of the median DIL volumes was 2.4 cm(3) (95% confidence interval, 0.9-4.4 cm(3)). Eighteen diagnostic studies with 1205 patients evaluated the diagnostic accuracy using multiparametric magnetic resonance imaging for intraprostatic cancer lesions. Evaluating 14,654 prostate segments, the diagnostic accuracy was 77%. Eleven therapeutic studies with 988 patients reported a RT boost for the DIL. The summary boost dose for the DIL was a mean of 89 Gy in 5 studies using intensity modulated RT (calculated as the equivalent dose in 2-Gy fractions) and a mean of 141 Gy in 4 studies using a combination of EBRT and brachytherapy (P = .018, t test). In 1 therapeutic study, 239 patients had a 98% 10-year disease-free survival rate. Many of our therapeutic studies used a boost dose to the DIL of > 90 Gy. The reported boost for DIL is effective and safe.

  6. 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.

  7. 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

  8. 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.

  9. Habituation of visual adaptation

    PubMed Central

    Dong, Xue; Gao, Yi; Lv, Lili; Bao, Min

    2016-01-01

    Our sensory system adjusts its function driven by both shorter-term (e.g. adaptation) and longer-term (e.g. learning) experiences. Most past adaptation literature focuses on short-term adaptation. Only recently researchers have begun to investigate how adaptation changes over a span of days. This question is important, since in real life many environmental changes stretch over multiple days or longer. However, the answer to the question remains largely unclear. Here we addressed this issue by tracking perceptual bias (also known as aftereffect) induced by motion or contrast adaptation across multiple daily adaptation sessions. Aftereffects were measured every day after adaptation, which corresponded to the degree of adaptation on each day. For passively viewed adapters, repeated adaptation attenuated aftereffects. Once adapters were presented with an attentional task, aftereffects could either reduce for easy tasks, or initially show an increase followed by a later decrease for demanding tasks. Quantitative analysis of the decay rates in contrast adaptation showed that repeated exposure of the adapter appeared to be equivalent to adaptation to a weaker stimulus. These results suggest that both attention and a non-attentional habituation-like mechanism jointly determine how adaptation develops across multiple daily sessions. PMID:26739917

  10. Adaptation of an existing cosmic ray ionization spectrometer experiment to Spacelab

    NASA Technical Reports Server (NTRS)

    Alvarado, U. R.; Stahle, C. V.; Ormes, J. F.

    1975-01-01

    This paper examines the technique of adapting an existing experiment to a Shuttle sortie mission. A sample cosmic-ray balloon experiment was studied to determine the feasibility of this cost-saving technique, which is applicable to a large spectrum of existing experiments, and to determine the programmatic impact and key problems. The main areas investigated include the determination of required modifications, steps in integration to the Spacelab/Shuttle, and the impact on orbital support and operations. One of the main problems in equipment adaptation is the acoustical loading during Shuttle boost; an environmental cover design presented herein shows a potential method to attain the required acoustic attenuation.

  11. Adaptive machine vision. Annual report

    SciTech Connect

    Stoner, W.W.; Brill, M.H.; Bergeron, D.W.

    1988-03-08

    The mission of the Strategic Defense Initiative is to develop defenses against threatening ballistic missiles. There are four distinct phases to the SDI defense; boost, post-boost, midcourse and terminal. In each of these phases, one or more machine-vision functions are required, such as pattern recognition, stereo image fusion, clutter rejection and discrimination. The SDI missions of coarse track, stereo track and discrimination are examined here from the point of view of a machine-vision system.

  12. Robust visual tracking via adaptive kernelized correlation filter

    NASA Astrophysics Data System (ADS)

    Wang, Bo; Wang, Desheng; Liao, Qingmin

    2016-10-01

    Correlation filter based trackers have proved to be very efficient and robust in object tracking with a notable performance competitive with state-of-art trackers. In this paper, we propose a novel object tracking method named Adaptive Kernelized Correlation Filter (AKCF) via incorporating Kernelized Correlation Filter (KCF) with Structured Output Support Vector Machines (SOSVM) learning method in a collaborative and adaptive way, which can effectively handle severe object appearance changes with low computational cost. AKCF works by dynamically adjusting the learning rate of KCF and reversely verifies the intermediate tracking result by adopting online SOSVM classifier. Meanwhile, we bring Color Names in this formulation to effectively boost the performance owing to its rich feature information encoded. Experimental results on several challenging benchmark datasets reveal that our approach outperforms numerous state-of-art trackers.

  13. 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.

  14. Identification of high-momentum top quarks, Higgs bosons, and W and Z bosons using boosted event shapes

    NASA Astrophysics Data System (ADS)

    Conway, J. S.; Bhaskar, R.; Erbacher, R. D.; Pilot, J.

    2016-11-01

    At the Large Hadron Collider, numerous physics processes expected within the standard model and theories beyond it give rise to very-high-momentum particles decaying to multihadronic final states. Development of algorithms for efficient identification of such "boosted" particles while rejecting the background from multihadron jets from light quarks and gluons can greatly aid in the sensitivity of measurements and new particle searches. This paper presents a new method for identifying boosted high-mass particles using event shapes in Lorentz-boosted reference frames. Variables calculated in these frames for multihadronic jets can then be used as input to a large artificial neural network to discriminate their origin.

  15. 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…

  16. Comparison of different prime-boost regimes with DNA and recombinant Orf virus based vaccines expressing glycoprotein D of pseudorabies virus in pigs.

    PubMed

    van Rooij, E M A; Rijsewijk, F A M; Moonen-Leusen, H W; Bianchi, A T J; Rziha, H-J

    2010-02-17

    Both DNA and Orf virus (ORFV; Parapox virus) based vaccines have shown promise as alternatives for conventional vaccines in pigs against pseudorabies virus (PRV) infection causing Aujeszky's disease. In the present study we evaluated the efficacy of different prime-boost regimes in pigs in terms of immunogenicity and protection against challenge infection with PRV. The different prime-boost regimes consisted of the homologous prime-boost regimes (DNA followed by DNA or ORFV followed by ORFV) and the heterologous prime-boost regimes (DNA followed by ORFV and ORFV followed by DNA), all based on glycoprotein D (gD) of PRV. Moreover, we compared the efficacy of the different prime-boost regimes with the efficacy of a conventional modified live vaccine (MLV). The different prime-boost regimes resulted in different levels of immunity and protection against challenge infection. Most effective was the regime of priming with DNA vaccine followed by boosting with the ORFV based vaccine. This regime resulted in strong antibody responses, comparable to the antibody responses obtained after prime-boost vaccination with a conventional MLV vaccine. Also with regard to protection, the prime DNA-boost ORFV regime performed better than the other prime-boost regimes. This study demonstrates the potential of a heterologous prime-boost vaccination strategy against PRV based on a single antigen, and that in the natural host, the pig.

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

    PubMed Central

    Jinesh, GG; Molina, JR; Huang, L; Laing, NM; Mills, GB; Bar-Eli, M; Kamat, AM

    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

  18. External beam radiotherapy boosts to reduce the impact caused by edema in prostate permanent seed implants

    NASA Astrophysics Data System (ADS)

    Yue, Ning; Mori, Jonathan; Nath, Ravinder; Heron, Dwight E.; Saiful Huq, M.

    2006-05-01

    In prostate permanent seed implants, it has been shown that edema caused by the surgical procedure decreases dose coverage and hence may reduce treatment efficacy. This reduction in treatment efficacy has been characterized by an increase in tumour cell survival, and biomathematical models have been developed to calculate the tumour cell survival increases in seed implanted prostates of different edema magnitudes and durations. External beam boosts can be utilized to neutralize the negative impact of edema so that originally desired treatment efficacy can be achieved. In this study, a linear quadratic model is used to determine fractionation sizes of the external beam boosts for both 125I and 103Pd seed implants. Calculations were performed for prostates of different edema magnitudes and durations, and for tumour cells of different repair rates and repopulation rates.

  19. 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.

  20. Brachytherapy boost to the tumour bed in high risk patients after limited surgery for breast cancer.

    PubMed

    Ulutin, H C; Ash, D; Dodwell, D

    2003-05-01

    The results of treatment for 174 patients at high risk of local recurrence, referred for radiotherapy after conservative surgery for early breast cancer, are evaluated. Microscopic margin involvement, extensive carcinoma in situ, and vascular/lymphatic invasion were the main risk factors for local recurrence. Whole-breast irradiation (40 Gy in 15 fractions over 3 weeks) followed with a brachytherapy boost (Ir192 wire implant or PDR Ir192) of 25 Gy was applied. Median follow-up was 80 months. The actuarial 6-year overall survival rate was 91% and the within breast recurrence-free survival was 88%. The most common risk factor among those recurring within the breast was involved surgical margins (13 out of 17). Cosmesis was reported to be good or excellent in 79% of cases. In patients at high risk for local recurrence, tumour-bed boost with brachytherapy can provide satisfactory local control after limited surgery and external radiotherapy.

  1. A guidance-motivated sensitivity analysis of an aero-assisted boost vehicle

    NASA Technical Reports Server (NTRS)

    Taylor, L. W.; Gracey, C.; Armstrong, C. D.

    1986-01-01

    A simple model of an aero-assisted booster is used to examine the contributions of propulsion system type, aerodynamic lift and flight trajectory to the efficiency with which payloads can be placed into low earth orbit. The higher propulsive efficiency of ramjet and scramjet propulsion has the potential of increasing the payload mass ratio significantly. The contributions of turbojet propulsion and aerodynamic lift are less significant. The additional complexity involved in using aerodynamic propulsion and lift requires dealing with a more comprehensive set of design variables than for rocket boosters. The approach taken is to derive a set of sensitivity functions which relate booster performance to the design variables. The problems of optimum mixing of aerodynamic lift with thrust and determining the optimal boost trajectory is treated. The potential payload capacity of a horizontal take-off air-breathing boost vehicle is examined. The optimization problem which considers propulsive efficiency, aerodynamic configuration, and control and guidance issues is discussed.

  2. Probing the two-Higgs-doublet wedge region with charged Higgs boson decays to boosted jets

    NASA Astrophysics Data System (ADS)

    Pedersen, Keith; Sullivan, Zack

    2017-02-01

    Two-Higgs-doublet extensions of the standard model, such as supersymmetry, predict the existence of charged Higgs bosons. We explore the reach for TeV-scale charged Higgs bosons through their associated production with top quarks, and their decay to boosted top jets and μx -tagged boosted bottom jets, at a 14 TeV CERN Large Hadron Collider and at a 100 TeV Future Circular Collider. In particular, we show the moderate tan β "wedge" region of parameter space cannot be probed at the Large Hadron Collider for TeV-scale H± because the cross section is too small. However, a 100 TeV future proton collider can close the wedge region below 2 TeV, and search for H± up to 6 TeV.

  3. Co-occurrence frequency evaluated with large language corpora boosts semantic priming effects.

    PubMed

    Brunellière, Angèle; Perre, Laetitia; Tran, ThiMai; Bonnotte, Isabelle

    2017-09-01

    In recent decades, many computational techniques have been developed to analyse the contextual usage of words in large language corpora. The present study examined whether the co-occurrence frequency obtained from large language corpora might boost purely semantic priming effects. Two experiments were conducted: one with conscious semantic priming, the other with subliminal semantic priming. Both experiments contrasted three semantic priming contexts: an unrelated priming context and two related priming contexts with word pairs that are semantically related and that co-occur either frequently or infrequently. In the conscious priming presentation (166-ms stimulus-onset asynchrony, SOA), a semantic priming effect was recorded in both related priming contexts, which was greater with higher co-occurrence frequency. In the subliminal priming presentation (66-ms SOA), no significant priming effect was shown, regardless of the related priming context. These results show that co-occurrence frequency boosts pure semantic priming effects and are discussed with reference to models of semantic network.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  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

    2016-11-01

    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.

  9. 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.

  10. Dosimetric comparison of simultaneous integrated boost with whole-breast irradiation for early breast cancer

    PubMed Central

    Choi, Kyu Hye; Kim, Shin-Wook

    2017-01-01

    Purpose The purpose of this study was to identify a more suitable boost plan for simultaneously integrated boost scheme in patients with breast cancer by comparing among 3 types of whole-breast irradiation plus tumor bed boost plans. Methods Twenty patients who received radiotherapy following breast-conserving surgery for early breast cancer were enrolled in this study. We performed 1 type of electron plan (E1P plan) and 2 types of 3-dimensional conformal plans using a photon (P3P and P5P plans). The dosimetric parameters for the heart, total lung and the target volume between the 3 treatment types were compared. Results For the tumor bed, the difference in the mean dose between the 3 plans was maximally 0.1 Gy. For normal breast parenchyma, the difference in the mean dose between the 3 plans was maximally 1.1 Gy. In the dose range over the prescribed dose of 51 Gy, V55 and V60 in the E1P plan were lower than those in the P3P and P5P plans, which indicated that the E1P plan was more suitable than the P3P and P5P plans. In case of the heart and total lung, the values of clinically important parameters were slightly higher in the E1P plan than in the P3P and P5P plans. However, these differences were less than 2%. Conclusion We observed that a simple electron plan for tumor bed boost is preferable over multi-field photon plans in terms of the target volume coverage and normal tissue sparing. PMID:28273157

  11. Design and Performance Evaluation of a 200 deg C Interleaved Boost Converter (Preprint)

    DTIC Science & Technology

    2012-09-01

    were measured under heated chamber conditions . Load and input powers were measured at the chamber entry/exit lugs. The converter efficiency as a...200 V, 1.85 kW case. As seen from the individual boost leg power dissipation columns in Table III, a slightly unbalanced current condition between...instrumentation and localized drive electronics for oil and gas recovery), and aircraft and spacecraft (turbine engines, motor drives, and space

  12. External beam boost irradiation for clinically positive pelvic nodes in patients with uterine cervical cancer

    PubMed Central

    Ariga, Takuro; Toita, Takafumi; Kasuya, Goro; Nagai, Yutaka; Inamine, Morihiko; Kudaka, Wataru; Kakinohana, Yasumasa; Aoki, Youichi; Murayama, Sadayuki

    2013-01-01

    The purpose of this study was to retrospectively analyze the treatment results of boost external beam radiotherapy (EBRT) to clinically positive pelvic nodes in patients with uterine cervical cancer. The study population comprised 174 patients with FIGO stages 1B1–4A cervical cancer who were treated with definitive radiotherapy (RT) or concurrent chemoradiotherapy (CCRT) and high-dose-rate intracavitary brachytherapy (HDR-ICBT). Patients with positive para-aortic or common iliac nodes (≥10 mm in the shortest diameter, as evaluated by CT/MRI) were ineligible for the study. Fifty-seven patients (33%) had clinically positive pelvic nodes. The median maximum diameter of the nodes was 15 mm (range, 10–60 mm) and the median number of positive lymph nodes was two (range, one to four). Fifty-two of 57 patients (91%) with positive nodes were treated with boost EBRT (6–10 Gy in three to five fractions). The median prescribed dose of EBRT for nodes was 56 Gy. The median follow-up time for all patients was 66 months (range, 3–142 months). The 5-year overall survival rate, disease-free survival rate and pelvic control rate for patients with positive and negative nodes were 73% and 92% (P = 0.001), 58% and 84% (P < 0.001), and 83% and 92% (P = 0.082), respectively. Five of 57 node-positive patients (9%) developed pelvic node recurrences. All five patients with nodal failure had concomitant cervical failure and/or distant metastases. No significant difference was observed with respect to the incidence or severity of late complications by application of boost EBRT. The current retrospective study demonstrated that boost EBRT to positive pelvic nodes achieves favorable nodal control without increasing late complications. PMID:23365264

  13. 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.

  14. Non-Inverted Buck-Boost Converters with Dual Delta Sigma Modulators

    NASA Astrophysics Data System (ADS)

    Kobori, Yasunori; Kono, Masashi; Shimizu, Toshihiko; Kobayashi, Haruo

    This paper presents a new control circuit to create high-performance non-inverted Buck-Boost converter with dual ⊿∑ modulations. Experimental load regulation, corresponding to load current steps of ±0.5A, is within 45mVpp, and the efficiency without synchronized rectifier is 83% at input voltage 2.5V and load current 0.8A.

  15. 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%.

  16. 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

  17. 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.

  18. Readapting the adaptive immune response - therapeutic strategies for atherosclerosis.

    PubMed

    Sage, Andrew P; Mallat, Ziad

    2017-01-04

    Cardiovascular diseases remain a major global health issue, with the development of atherosclerosis as a major underlying cause. Our treatment of cardiovascular disease has improved greatly over the past three decades, but much remains to be done reduce disease burden. Current priorities include reducing atherosclerosis advancement to clinically significant stages and preventing plaque rupture or erosion. Inflammation and involvement of the adaptive immune system influences all these aspects and therefore is one focus for future therapeutic development. The atherosclerotic vascular wall is now recognized to be invaded from both sides (arterial lumen and adventitia), for better or worse, by the adaptive immune system. Atherosclerosis is also affected at several stages by adaptive immune responses, overall providing many opportunities to target these responses and to reduce disease progression. Protective influences that may be defective in diseased individuals include humoral responses to modified LDL and regulatory T cell responses. There are many strategies in development to boost these pathways in humans, including vaccine-based therapies. The effects of various existing adaptive immune targeting therapies, such as blocking critical co-stimulatory pathways or B cell depletion, on cardiovascular disease are beginning to emerge with important consequences for both autoimmune disease patients and the potential for wider use of such therapies. Entering the translation phase for adaptive immune targeting therapies is an exciting and promising prospect.

  19. HIV's evasion of host's NK cell response and novel ways of its countering and boosting anti-HIV immunity.

    PubMed

    Ahmad, Ali; Ahmad, Rasheed

    2003-07-01

    NK cells were characterized by their ability to spontaneously kill certain tumor and virus-infected cells. They constitute first line of defense against invading pathogens and usually become activated in viral infections particularly in early phases. Activated NK cells play a crucial role in the induction and amplification of virus-specific immunity by providing IFN-gamma and "danger signal". The functional activities of NK cells are regulated by a balance between the engagement of their inhibitory and activating receptors. In recent years, the discovery of several MHC and non-MHC binding NK receptors has provided important insights regarding NK cell biology and its role in viral infections. These receptors are increasingly being viewed as important regulators of immune response. Like many other viruses, HIV also seems to activate NK cells. However, several studies have reported compromised NK cell functions in HIV-infected individuals. The virus employs several strategies to counter the host's NK cell response, e.g., a differential downregulation of MHC class I molecules on the surface of infected cells, a dysregulated production of NK cell function-enhancing cytokines, direct inhibitory effects of certain viral proteins on NK cell functions, and changes in the expression of NK cell receptors, etc. The individuals expressing activating NK cell receptors and their cognate MHC ligands have activated NK cells. The development of AIDS is significantly delayed in these individuals after HIV infection. The discovery of NK receptors and their ligands has opened new avenues of developing AIDS vaccine and boosting innate and adaptive antiviral immunity in HIV-infected individuals.

  20. Do warning calls boost survival of signal recipients? Evidence from a field experiment in a group-living bird species

    PubMed Central

    2013-01-01

    Introduction Warning calls are a widespread anti-predator adaptation, which can signal unprofitability to predators or alert other potential targets of the predator. Although it is tacitly assumed that the recipients of warning calls experience a reduction in predation risk, this crucial assumption remains untested. Here I tested this hypothesis with a field experiment in the group-living Siberian jay, Perisoreus infaustus. I exposed male or female breeding adults that were foraging together with a non-breeder (related or unrelated) to a model of their main predator (goshawk Accipiter gentilis) in autumn. I then recorded the warning call response of breeders as well as the reaction time of non-breeders, and followed the subsequent survival of non-breeders until spring. Results In most experiments (73%), non-breeders were warned by the more experienced breeders. Warning calls almost halved the reaction time of non-breeders during the experiment and influenced the survival of call recipients: non-breeders that were warned had a higher subsequent survival (19 out of 23) than non-breeders that were not warned (2 out of 5). However, neither kinship, group size, the age of the non-breeder, or the habitat structure of the territory had an influence on the survival subsequent to the experiments. Conclusions Since earlier studies showed that breeders are consistent in their warning call investment across different contexts, breeders that did warn non-breeders in the experiment were likely to have done so in subsequent, natural attacks. Consequently non-breeders living with breeders that called had a better chance of surviving predator attacks. Thus, these results suggest that warning calls have the potential to boost the survival of signal recipients, confirming a pivotal, yet hitherto untested assumption of the effect of warning calls. PMID:23941356

  1. 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.

  2. Diesel Combustion and Emission Using High Boost and High Injection Pressure in a Single Cylinder Engine

    NASA Astrophysics Data System (ADS)

    Aoyagi, Yuzo; Kunishima, Eiji; Asaumi, Yasuo; Aihara, Yoshiaki; Odaka, Matsuo; Goto, Yuichi

    Heavy-duty diesel engines have adopted numerous technologies for clean emissions and low fuel consumption. Some are direct fuel injection combined with high injection pressure and adequate in-cylinder air motion, turbo-intercooler systems, and strong steel pistons. Using these technologies, diesel engines have achieved an extremely low CO2 emission as a prime mover. However, heavy-duty diesel engines with even lower NOx and PM emission levels are anticipated. This study achieved high-boost and lean diesel combustion using a single cylinder engine that provides good engine performance and clean exhaust emission. The experiment was done under conditions of intake air quantity up to five times that of a naturally aspirated (NA) engine and 200MPa injection pressure. The adopted pressure booster is an external supercharger that can control intake air temperature. In this engine, the maximum cylinder pressure was increased and new technologies were adopted, including a monotherm piston for endurance of Pmax =30MPa. Moreover, every engine part is newly designed. As the boost pressure increases, the rate of heat release resembles the injection rate and becomes sharper. The combustion and brake thermal efficiency are improved. This high boost and lean diesel combustion creates little smoke; ISCO and ISTHC without the ISNOx increase. It also yields good thermal efficiency.

  3. Bayesian Mapping Reveals That Attention Boosts Neural Responses to Predicted and Unpredicted Stimuli.

    PubMed

    Garrido, Marta I; Rowe, Elise G; Halász, Veronika; Mattingley, Jason B

    2017-04-10

    Predictive coding posits that the human brain continually monitors the environment for regularities and detects inconsistencies. It is unclear, however, what effect attention has on expectation processes, as there have been relatively few studies and the results of these have yielded contradictory findings. Here, we employed Bayesian model comparison to adjudicate between 2 alternative computational models. The "Opposition" model states that attention boosts neural responses equally to predicted and unpredicted stimuli, whereas the "Interaction" model assumes that attentional boosting of neural signals depends on the level of predictability. We designed a novel, audiospatial attention task that orthogonally manipulated attention and prediction by playing oddball sequences in either the attended or unattended ear. We observed sensory prediction error responses, with electroencephalography, across all attentional manipulations. Crucially, posterior probability maps revealed that, overall, the Opposition model better explained scalp and source data, suggesting that attention boosts responses to predicted and unpredicted stimuli equally. Furthermore, Dynamic Causal Modeling showed that these Opposition effects were expressed in plastic changes within the mismatch negativity network. Our findings provide empirical evidence for a computational model of the opposing interplay of attention and expectation in the brain.

  4. 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

  5. "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.

  6. 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.

  7. 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.

  8. 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.

  9. Clinical Exposure Boost Predictions by Integrating Cytochrome P450 3A4-Humanized Mouse Studies With PBPK Modeling.

    PubMed

    Zhang, Jin; Heimbach, Tycho; Scheer, Nico; Barve, Avantika; Li, Wenkui; Lin, Wen; He, Handan

    2016-04-01

    NVS123 is a poorly water-soluble protease 56 inhibitor in clinical development. Data from in vitro hepatocyte studies suggested that NVS123 is mainly metabolized by CYP3A4. As a consequence of limited solubility, NVS123 therapeutic plasma exposures could not be achieved even with high doses and optimized formulations. One approach to overcome NVS123 developability issues was to increase plasma exposure by coadministrating it with an inhibitor of CYP3A4 such as ritonavir. A clinical boost effect was predicted by using physiologically based pharmacokinetic (PBPK) modeling. However, initial boost predictions lacked sufficient confidence because a key parameter, fraction of drug metabolized by CYP3A4 (fmCYP3A4), could not be estimated with accuracy on account of disconnects between in vitro and in vivo preclinical data. To accurately estimate fmCYP3A4 in human, an in vivo boost effect study was conducted using CYP3A4-humanized mouse model which showed a 33- to 56-fold exposure boost effect. Using a top-down approach, human fmCYP3A4 for NVS123 was estimated to be very high and included in the human PBPK modeling to support subsequent clinical study design. The combined use of the in vivo boost study in CYP3A4-humanized mouse model mice along with PBPK modeling accurately predicted the clinical outcome and identified a significant NVS123 exposure boost (∼42-fold increase) with ritonavir.

  10. Effects of ApoE4 and maternal history of dementia on hippocampal atrophy

    PubMed Central

    Andrawis, John P.; Hwang, Kristy S.; Green, Amity E.; Kotlerman, Jenny; Elashoff, David; Morra, Jonathan H.; Cummings, Jeffrey L.; Toga, Arthur W.; Thompson, Paul M.; Apostolova, Liana G.

    2010-01-01

    We applied an automated hippocampal segmentation technique based on adaptive boosting (AdaBoost) to the 1.5T MRI baseline and 1-year follow-up data of 243 subjects with mild cognitive impairment (MCI), 96 with Alzheimer's disease (AD) and 145 normal controls (NC) scanned as part of the Alzheimer's Disease Neuroimaging Initiative (ADNI). MCI subjects with positive maternal history of dementia had smaller hippocampal volumes at baseline and at follow-up, and greater 12-month atrophy rates than subjects with negative maternal history. 3D maps and volumetric multiple regression analyses demonstrated a significant effect of positive maternal history of dementia on hippocampal atrophy in MCI and AD after controlling for age, ApoE4 genotype and paternal history of dementia, resp. ApoE4 showed an independent effect on hippocampal atrophy in MCI and AD and in the pooled sample. PMID:20833446

  11. 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.

  12. Resilience through adaptation

    PubMed Central

    van Voorn, George A. K.; Ligtenberg, Arend; Molenaar, Jaap

    2017-01-01

    Adaptation of agents through learning or evolution is an important component of the resilience of Complex Adaptive Systems (CAS). Without adaptation, the flexibility of such systems to cope with outside pressures would be much lower. To study the capabilities of CAS to adapt, social simulations with agent-based models (ABMs) provide a helpful tool. However, the value of ABMs for studying adaptation depends on the availability of methodologies for sensitivity analysis that can quantify resilience and adaptation in ABMs. In this paper we propose a sensitivity analysis methodology that is based on comparing time-dependent probability density functions of output of ABMs with and without agent adaptation. The differences between the probability density functions are quantified by the so-called earth-mover’s distance. We use this sensitivity analysis methodology to quantify the probability of occurrence of critical transitions and other long-term effects of agent adaptation. To test the potential of this new approach, it is used to analyse the resilience of an ABM of adaptive agents competing for a common-pool resource. Adaptation is shown to contribute positively to the resilience of this ABM. If adaptation proceeds sufficiently fast, it may delay or avert the collapse of this system. PMID:28196372

  13. 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)

  14. 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.

  15. 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

  16. Augmenting antitumor T-cell responses to mimotope vaccination by boosting with native tumor antigens.

    PubMed

    Buhrman, Jonathan D; Jordan, Kimberly R; U'ren, Lance; Sprague, Jonathan; Kemmler, Charles B; Slansky, Jill E

    2013-01-01

    Vaccination with antigens expressed by tumors is one strategy for stimulating enhanced T-cell responses against tumors. However, these peptide vaccines rarely result in efficient expansion of tumor-specific T cells or responses that protect against tumor growth. Mimotopes, or peptide mimics of tumor antigens, elicit increased numbers of T cells that crossreact with the native tumor antigen, resulting in potent antitumor responses. Unfortunately, mimotopes may also elicit cells that do not crossreact or have low affinity for tumor antigen. We previously showed that one such mimotope of the dominant MHC class I tumor antigen of a mouse colon carcinoma cell line stimulates a tumor-specific T-cell clone and elicits antigen-specific cells in vivo, yet protects poorly against tumor growth. We hypothesized that boosting the mimotope vaccine with the native tumor antigen would focus the T-cell response elicited by the mimotope toward high affinity, tumor-specific T cells. We show that priming T cells with the mimotope, followed by a native tumor-antigen boost, improves tumor immunity compared with T cells elicited by the same prime with a mimotope boost. Our data suggest that the improved tumor immunity results from the expansion of mimotope-elicited tumor-specific T cells that have increased avidity for the tumor antigen. The enhanced T cells are phenotypically distinct and enriched for T-cell receptors previously correlated with improved antitumor immunity. These results suggest that incorporation of native antigen into clinical mimotope vaccine regimens may improve the efficacy of antitumor T-cell responses.

  17. Puncture initial data for black-hole binaries with high spins and high boosts

    NASA Astrophysics Data System (ADS)

    Ruchlin, Ian; Healy, James; Lousto, Carlos O.; Zlochower, Yosef

    2017-01-01

    We solve the Hamiltonian and momentum constraints of general relativity for two black holes with nearly extremal spins and relativistic boosts in the puncture formalism. We use a non-conformally-flat ansatz with an attenuated superposition of two Lorentz-boosted, conformally Kerr or conformally Schwarzschild 3-metrics and their corresponding extrinsic curvatures. We compare evolutions of these data with the standard Bowen-York conformally flat ansatz (technically limited to intrinsic spins χ =S /MADM2=0.928 and boosts P /MADM=0.897 ), finding, typically, an order of magnitude smaller burst of spurious radiation and agreement with inspiral and merger. As a first case study, we evolve two equal-mass black holes from rest with an initial separation of d =12 M and spins χi=Si/mi2=0.99 , compute the waveforms produced by the collision, the energy and angular momentum radiated, and the recoil of the final remnant black hole. We find that the black-hole trajectories curve at close separations, leading to the radiation of angular momentum. We also study orbiting nonspinning and moderate-spin black-hole binaries and compare these with standard Bowen-York data. We find a substantial reduction in the nonphysical initial burst of radiation which leads to cleaner waveforms. Finally, we study the case of orbiting binary black-hole systems with spin magnitude χi=0.95 in an aligned configuration and compare waveform and final remnant results with those of the SXS Collaboration [54 A. H. Mroue et al., Phys. Rev. Lett. 111, 241104 (2013)., 10.1103/PhysRevLett.111.241104], finding excellent agreement. This represents the first moving puncture evolution of orbiting and spinning black holes exceeding the Bowen-York limit. Finally, we study different choices of the initial lapse and lapse evolution equation in the moving puncture approach to improve the accuracy and efficiency of the simulations.

  18. Prime-boost vaccinations using recombinant flavivirus replicon and vaccinia virus vaccines: an ELISPOT analysis.

    PubMed

    Rattanasena, Paweena; Anraku, Itaru; Gardner, Joy; Le, Thuy T; Wang, Xiang Ju; Khromykh, Alexander A; Suhrbier, Andreas

    2011-03-01

    Recombinant Kunjin replicon virus-like particle (VLP), vaccinia virus (rVV) and DNA vaccines were tested in a large series of prime-boost vaccinations using interferon (IFN)γ ELISPOT assays that reflected effector (E), effector memory (EM) and central memory (CM) responses. All vaccine constructs encoded the murine polytope immunogen and responses to four CD8 T-cell epitopes (TYQRTRALV, SYIPSAEKI, YPHFMPTNL and RPQASGVYM) were measured. VLP/rVV out performed (by 14- to 20-fold) DNA/rVV for induction of CM responses, whereas EM responses were only marginally increased. DNA/VLP induced more EM, but not CM responses, than VLP alone, illustrating that DNA priming is not universally beneficial. rVV/VLP gave comparable results to VLP/rVV combinations, although the former induced approximately threefold more E responses, illustrating the utility of poxvirus priming in this setting. Although higher doses of VLP and rVV increased responses after single immunizations, such dose increases provided only marginal benefit in heterologous prime-boost settings. Triple combinations also provided no benefit over two vaccinations. DNA vaccination was associated with broad CM, but not EM responses, and the breadth of EM and E responses was significantly improved by increasing viral vector dose. VLP/rVV, rather than DNA priming, induced T cells with consistently high IFNγ secretion profiles across all ELISPOT measures. Vector-specific CD8 T-cell responses generally correlated well with immunogen-specific responses, although, as expected, single use of each vector reduced the relative levels of vector-specific responses. These experiments illustrate the utility of replicons in heterologous prime-boost vaccinations, and illustrate the diversity of data that can be obtained from ELISPOT analyses.

  19. Natural immune boosting in pertussis dynamics and the potential for long-term vaccine failure.

    PubMed

    Lavine, Jennie S; King, Aaron A; Bjørnstad, Ottar N

    2011-04-26

    Incidence of whooping cough, unlike many other childhood diseases for which there is an efficacious vaccine, has been increasing over the past twenty years despite high levels of vaccine coverage. Its reemergence has been particularly noticeable among teenagers and adults. Many hypotheses have been put forward to explain these two patterns, but parsimonious reconciliation of clinical data on the limited duration of immunity with both pre- and postvaccine era age-specific incidence remains a challenge. We consider the immunologically relevant, yet epidemiologically largely neglected, possibility that a primed immune system can respond to a lower dose of antigen than a naive one. We hypothesize that during the prevaccine era teenagers' and adults' primed immunity was frequently boosted by reexposure, so maintaining herd immunity in the face of potentially eroding individual immunity. In contrast, low pathogen circulation in the current era, except during epidemic outbreaks, allows immunity to be lost before reexposure occurs. We develop and analyze an age-structured model that encapsulates this hypothesis. We find that immune boosting must be more easily triggered than primary infection to account for age-incidence data. We make age-specific and dynamical predictions through bifurcation analysis and simulation. The boosting model proposed here parsimoniously captures four key features of pertussis data from highly vaccinated countries: (i) the shift in age-specific incidence, (ii) reemergence with high vaccine coverage, (iii) the possibility for cyclic dynamics in the pre- and postvaccine eras, and (iv) the apparent shift from susceptible-infectious-recovered (SIR)-like to susceptible-infectious-recovered-susceptible (SIRS)-like phenomenology of infection and immunity to Bordetella pertussis.

  20. 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).

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Soft-Switched Neutral-Point-Clamped Single-Phase Boost Rectifier

    NASA Astrophysics Data System (ADS)

    Itoh, Ryozo; Ishizaka, Kouichi

    A soft-switched neutral-point-clamped single-phase boost rectifier capable of compensating the imbalance load voltage is studied. This is based on a single-phase rectifier, in which an inductor is placed in series with the AC supply to resonate with a capacitor connected across the DC output of a full-bridge rectifier and the switching transition is mainly governed by a series resonance. The experimental prototype using insulated-gate bipolar transistors is implemented to investigate the operation under the charge control. The experimental results confirm that the rectifier has a neutral-point-clamp feature providing a good quality AC current.

  6. 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.

  7. The reconstruction of jets, missing ET and boosted heavy particles with ATLAS in Run 2

    NASA Astrophysics Data System (ADS)

    Santoni, Claudio

    2016-11-01

    The reconstruction of jets, missing ET and boosted heavy particles decaying hadronically has proved to be of extreme importance in Run 1 of the LHC, and has great potential to uncover new physics with Run 2 data. The excellent ATLAS detector capabilities, in particular its high-resolution longitudinally segmented calorimeter and inner detector, have enabled the development of complex clustering and calibration algorithms for the reconstruction of such quantities. In this talk the performance of the tools determined using Run 2 data are presented.

  8. A Template Measurement of the Top Quark Angular Distribution Using Boosted Lepton + Jets Events

    NASA Astrophysics Data System (ADS)

    Eminizer, Nick; CMS Collaboration

    2017-01-01

    We present a template-based technique for measuring the angular distribution of top quark pairs decaying semileptonically using data collected by the CMS experiment at the LHC. The analysis is optimized for high-momentum ``boosted'' decays wherein the hadronically decaying top quark's jets become either partially or fully merged, and the final state lepton is not necessarily isolated from nearby jets. The technique can be used to examine multiple physics processes affecting the angular distribution of top pairs, including the parton-level top quark forward-backward asymmetry AFB and anomalous chromoelectric/chromomagnetic moments. CMS is the Compact Muon Solenoid experiment at the Large Hadron Collider.

  9. Speeding Up Simulations of Relativistic Systems using an Optimal Boosted Frame

    SciTech Connect

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

    2009-01-27

    It can 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 has been pointed out that algorithmic difficulties related to discretization errors may have to be overcome in order to take full advantage of the potential speedup. We summarize the findings, the difficulties and their solutions, and show that the technique enables simulations important to several areas of accelerator physics that are otherwise problematic, including self-consistent modeling in three-dimensions of laser wokefield accelerator stages at energies of 10 GeV and above.

  10. Lorentz Boosted Potential for a Two-Body System with Unequal Masses

    NASA Astrophysics Data System (ADS)

    Kamada, H.; Polyzou, W. N.; Witała, H.; Miyagawa, K.

    2014-04-01

    We produce a Lorentz boosted two-body potential for particles of different mass that is phase equivalent to a given realistic non-relativistic two-body potential. The relativistic potential is related to the nonrelativistic potential using the Coester-Pieper-Serduke scheme, which ensures that the same scattering wave functions are obtained from the relativistic and non-relativistic potentials. This implies that the phase shifts are identical functions of the relative momentum. To construct the potential we use an iterative scheme that generalizes one that has been applied successfully to two-body systems with equal masses.

  11. A New Approach for High Efficiency Buck-Boost DC/DC Converters Using Series Compensation

    NASA Astrophysics Data System (ADS)

    Itoh, Jun-Ichi; Fujii, Takashi

    This paper proposes a novel concept for non-isolated buck-boost DC/DC converter and control method. The proposed concept uses a series connection converter that only regulates the differential voltage between the input and output voltage. As a result, the power converter capacity is decreased. Moreover, the proposed circuit has advantages such as improved efficiency and losses reduction. The fundamental operation, control method, and design method of the proposed circuit are described in this paper. In addition, the validity of the proposed circuit is confirmed by carrying out simulations and experiments.

  12. Evaluation of a Modified BOOST Tool in the Acute Care Setting: A Retrospective Analysis.

    PubMed

    Robertson, Denise A

    Several readmission risk prediction tools exist but have had varying success in identifying patients at risk for readmission. The purpose of this project was to evaluate the effectiveness of a tool available within Project BOOST, Better Outcomes by Optimizing Safe Transitions, from the Society of Hospital Medicine. The tool was modified within the institution to include risk stratification scores in order to better identify the highest-risk patients. The modified risk tool may assist in predicting the risk of readmission in those patients with heart failure and chronic obstructive pulmonary disease who are discharged home.

  13. 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.

  14. Structure and boosting activity of a starch-degrading lytic polysaccharide monooxygenase.

    PubMed

    Lo Leggio, Leila; Simmons, Thomas J; Poulsen, Jens-Christian N; Frandsen, Kristian E H; Hemsworth, Glyn R; Stringer, Mary A; von Freiesleben, Pernille; Tovborg, Morten; Johansen, Katja S; De Maria, Leonardo; Harris, Paul V; Soong, Chee-Leong; Dupree, Paul; Tryfona, Theodora; Lenfant, Nicolas; Henrissat, Bernard; Davies, Gideon J; Walton, Paul H

    2015-01-22

    Lytic polysaccharide monooxygenases (LPMOs) are recently discovered enzymes that oxidatively deconstruct polysaccharides. LPMOs are fundamental in the effective utilization of these substrates by bacteria and fungi; moreover, the enzymes have significant industrial importance. We report here the activity, spectroscopy and three-dimensional structure of a starch-active LPMO, a representative of the new CAZy AA13 family. We demonstrate that these enzymes generate aldonic acid-terminated malto-oligosaccharides from retrograded starch and boost significantly the conversion of this recalcitrant substrate to maltose by β-amylase. The detailed structure of the enzyme's active site yields insights into the mechanism of action of this important class of enzymes.

  15. Starting Up in a Down Market, with a Boost From Entrepreneurship Graduate Programs

    NASA Astrophysics Data System (ADS)

    Taylor, Cyrus

    2003-03-01

    In the late 1990's, it seemed that any two graduate students and their dog could start and grow a high-tech company. With the collapse of, first, the internet sector, and, more recently, the telecommunications sector, there has been a traumatic shake-out among high tech firms, and the challenges facing new firms appear to have greatly increased. This talk will highlight the keys for physics entrepreneurs to survive and even thrive in this environment, with a special initial boost from new graduate programs combining business school and physics training. The infrastructure needed by educational programs designed to empower physicists as entrepreneurs is discussed.

  16. Search for boosted Stealth SUSY with photons and jets using 13TeV LHC data.

    NASA Astrophysics Data System (ADS)

    Kyriacou, Savvas; CMS Collaboration

    2017-01-01

    An analysis is designed and performed on proton-proton collision data collected by the CMS experiment at a center of mass energy of 13TeV, targeting the pair production of squarks with a final state composed of photons, jets and low missing transverse energy. This search, motivated by a number of models such as stealth supersymmetry, focuses on the boosted regime, where photons and gluons merge in multi-core jet configurations, investigating thus a previously unexplored region. Substructure variables such as N-subjettiness, are utilized to discriminate these structure rich jets against standard model background. The analysis development and results are presented.

  17. 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.

  18. 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

  19. Targeting the genital tract mucosa with a lipopeptide/recombinant adenovirus prime/boost vaccine induces potent and long-lasting CD8+ T cell immunity against herpes: importance of MyD88.

    PubMed

    Zhang, Xiuli; Dervillez, Xavier; Chentoufi, Aziz Alami; Badakhshan, Tina; Bettahi, Ilham; Benmohamed, Lbachir

    2012-11-01

    Targeting of the mucosal immune system of the genital tract with subunit vaccines has failed to induce potent and durable local CD8(+) T cell immunity, which is crucial for protection against many sexually transmitted viral pathogens, including HSV type 2 (HSV-2), which causes genital herpes. In this study, we aimed to investigate the potential of a novel lipopeptide/adenovirus type 5 (Lipo/rAdv5) prime/boost mucosal vaccine for induction of CD8(+) T cell immunity to protect the female genital tract from herpes. The lipopeptide vaccine and the rAdv5 vaccine express the immunodominant HSV-2 CD8(+) T cell epitope (gB(498-505)), and both were delivered intravaginally in the progesterone-induced B6 mouse model of genital herpes. Compared with mice immunized with the homologous lipopeptide/lipopeptide (Lipo/Lipo) vaccine, the Lipo/rAdv5 prime/boost immunized mice 1) developed potent and sustained HSV-specific CD8(+) T cells, detected in both the genital tract draining nodes and in the vaginal mucosa; 2) had significantly lower virus titers; 3) had decreased overt signs of genital herpes disease; and 4) did not succumb to lethal infection (p < 0.005) after intravaginal HSV-2 challenge. Polyfunctional CD8(+) T cells, producing IFN-γ, TNF-α, and IL-2 and exhibiting cytotoxic activity, were associated with protection (p < 0.005). The protective CD8(+) T cell response was significantly compromised in the absence of the adapter MyD88 (p = 0.0001). Taken together, these findings indicate that targeting of the vaginal mucosa with a Lipo/rAdv5 prime/boost vaccine elicits a potent, MyD88-dependent, and long-lasting mucosal CD8(+) T cell protective immunity against sexually transmitted herpes infection and disease.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Using injectable hydrogel markers to assess resimulation for boost target volume definition in a patient undergoing whole-breast radiotherapy

    SciTech Connect

    Patel, Henal; Goyal, Sharad; Kim, Leonard

    2015-01-01

    Several publications have recommended that patients undergoing whole-breast radiotherapy be resimulated for boost planning. The rationale for this is that the seroma may be smaller when compared with the initial simulation. However, the decision remains whether to use the earlier or later images to define an appropriate boost target volume. A patient undergoing whole-breast radiotherapy had new, injectable, temporary hydrogel fiducial markers placed 1 to 3 cm from the seroma at the time of initial simulation. The patient was resimulated 4.5 weeks later for conformal photon boost planning. Computed tomography (CT) scans acquired at the beginning and the end of whole-breast radiotherapy showed that shrinkage of the lumpectomy cavity was not matched by a corresponding reduction in the surrounding tissue volume, as demarcated by hydrogel markers. This observation called into question the usual interpretation of cavity shrinkage for boost target definition. For this patient, it was decided to define the boost target volume on the initial planning CT instead of the new CT.

  7. 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.

  8. Local adaptive tone mapping for video enhancement

    NASA Astrophysics Data System (ADS)

    Lachine, Vladimir; Dai, Min (.

    2015-03-01

    As new technologies like High Dynamic Range cameras, AMOLED and high resolution displays emerge on consumer electronics market, it becomes very important to deliver the best picture quality for mobile devices. Tone Mapping (TM) is a popular technique to enhance visual quality. However, the traditional implementation of Tone Mapping procedure is limited by pixel's value to value mapping, and the performance is restricted in terms of local sharpness and colorfulness. To overcome the drawbacks of traditional TM, we propose a spatial-frequency based framework in this paper. In the proposed solution, intensity component of an input video/image signal is split on low pass filtered (LPF) and high pass filtered (HPF) bands. Tone Mapping (TM) function is applied to LPF band to improve the global contrast/brightness, and HPF band is added back afterwards to keep the local contrast. The HPF band may be adjusted by a coring function to avoid noise boosting and signal overshooting. Colorfulness of an original image may be preserved or enhanced by chroma components correction by means of saturation function. Localized content adaptation is further improved by dividing an image to a set of non-overlapped regions and modifying each region individually. The suggested framework allows users to implement a wide range of tone mapping applications with perceptional local sharpness and colorfulness preserved or enhanced. Corresponding hardware circuit may be integrated in camera, video or display pipeline with minimal hardware budget

  9. Adaptive image steganography using contourlet transform

    NASA Astrophysics Data System (ADS)

    Fakhredanesh, Mohammad; Rahmati, Mohammad; Safabakhsh, Reza

    2013-10-01

    This work presents adaptive image steganography methods which locate suitable regions for embedding by contourlet transform, while embedded message bits are carried in discrete cosine transform coefficients. The first proposed method utilizes contourlet transform coefficients to select contour regions of the image. In the embedding procedure, some of the contourlet transform coefficients may change which may cause errors at the message extraction phase. We propose a novel iterative procedure to resolve such problems. In addition, we have proposed an improved version of the first method in which it uses an advanced embedding operation to boost its security. Experimental results show that the proposed base method is an imperceptible image steganography method with zero retrieval error rate. Comparisons with other steganography methods which utilize contourlet transform show that our proposed method is able to retrieve all messages perfectly, whereas the others fail. Moreover, the proposed method outperforms the ContSteg method in terms of PSNR and the higher-order statistics steganalysis method. Experimental evaluations of our methods with the well known DCT-based steganography algorithms have demonstrated that our improved method has superior performance in terms of PSNR and SSIM, and is more secure against the steganalysis attack.

  10. 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.

  11. 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.

  12. Boosting joint models for longitudinal and time-to-event data.

    PubMed

    Waldmann, Elisabeth; Taylor-Robinson, David; Klein, Nadja; Kneib, Thomas; Pressler, Tania; Schmid, Matthias; Mayr, Andreas

    2017-03-21

    Joint models for longitudinal and time-to-event data have gained a lot of attention in the last few years as they are a helpful technique clinical studies where longitudinal outcomes are recorded alongside event times. Those two processes are often linked and the two outcomes should thus be modeled jointly in order to prevent the potential bias introduced by independent modeling. Commonly, joint models are estimated in likelihood-based expectation maximization or Bayesian approaches using frameworks where variable selection is problematic and that do not immediately work for high-dimensional data. In this paper, we propose a boosting algorithm tackling these challenges by being able to simultaneously estimate predictors for joint models and automatically select the most influential variables even in high-dimensional data situations. We analyze the performance of the new algorithm in a simulation study and apply it to the Danish cystic fibrosis registry that collects longitudinal lung function data on patients with cystic fibrosis together with data regarding the onset of pulmonary infections. This is the first approach to combine state-of-the art algorithms from the field of machine-learning with the model class of joint models, providing a fully data-driven mechanism to select variables and predictor effects in a unified framework of boosting joint models.

  13. The identification of complex interactions in epidemiology and toxicology: a simulation study of boosted regression trees

    PubMed Central

    2014-01-01

    Background There is a need to evaluate complex interaction effects on human health, such as those induced by mixtures of environmental contaminants. The usual approach is to formulate an additive statistical model and check for departures using product terms between the variables of interest. In this paper, we present an approach to search for interaction effects among several variables using boosted regression trees. Methods We simulate a continuous outcome from real data on 27 environmental contaminants, some of which are correlated, and test the method’s ability to uncover the simulated interactions. The simulated outcome contains one four-way interaction, one non-linear effect and one interaction between a continuous variable and a binary variable. Four scenarios reflecting different strengths of association are simulated. We illustrate the method using real data. Results The method succeeded in identifying the true interactions in all scenarios except where the association was weakest. Some spurious interactions were also found, however. The method was also capable to identify interactions in the real data set. Conclusions We conclude that boosted regression trees can be used to uncover complex interaction effects in epidemiological studies. PMID:24993424

  14. Hypofractionated proton boost combined with external beam radiotherapy for treatment of localized prostate cancer.

    PubMed

    Johansson, Silvia; Aström, Lennart; Sandin, Fredrik; Isacsson, Ulf; Montelius, Anders; Turesson, Ingela

    2012-01-01

    Proton boost of 20 Gy in daily 5 Gy fractions followed by external beam radiotherapy (EBRT) of 50 Gy in daily 2 Gy fractions were given to 278 patients with prostate cancer with T1b to T4N0M0 disease. Fifty-three percent of the patients received neoadjuvant androgen deprivation therapy (N-ADT). The medium followup was 57 months. The 5-year PSA progression-free survival was 100%, 95%, and 74% for low-, intermediate-, and high-risk patients, respectively. The toxicity evaluation was supported by a patient-reported questionnaire before every consultant visit. Cumulative probability and actuarial prevalence of genitourinary (GU) and gastrointestinal (GI) toxicities are presented according to the RTOG classification. N-ADT did not influence curability. Mild pretreatment GU-symptoms were found to be a strong predictive factor for GU-toxicity attributable to treatment. The actuarial prevalence declined over 3 to 5 years for both GU and GI toxicities, indicating slow resolution of epithelial damage to the genitourinary and gastrointestinal tract. Bladder toxicities rather than gastrointestinal toxicities seem to be dose limiting. More than 5-year followup is necessary to reveal any sign of true progressive late side effects of the given treatment. Hypofractionated proton-boost combined with EBRT is associated with excellent curability of localized PC and acceptable frequencies of treatment toxicity.

  15. Boosting CRISPR/Cas9 multiplex editing capability with the endogenous tRNA-processing system.

    PubMed

    Xie, Kabin; Minkenberg, Bastian; Yang, Yinong

    2015-03-17

    The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 nuclease (Cas9) system is being harnessed as a powerful tool for genome engineering in basic research, molecular therapy, and crop improvement. This system uses a small guide RNA (gRNA) to direct Cas9 endonuclease to a specific DNA site; thus, its targeting capability is largely constrained by the gRNA-expressing device. In this study, we developed a general strategy to produce numerous gRNAs from a single polycistronic gene. The endogenous tRNA-processing system, which precisely cleaves both ends of the tRNA precursor, was engineered as a simple and robust platform to boost the targeting and multiplex editing capability of the CRISPR/Cas9 system. We demonstrated that synthetic genes with tandemly arrayed tRNA-gRNA architecture were efficiently and precisely processed into gRNAs with desired 5' targeting sequences in vivo, which directed Cas9 to edit multiple chromosomal targets. Using this strategy, multiplex genome editing and chromosomal-fragment deletion were readily achieved in stable transgenic rice plants with a high efficiency (up to 100%). Because tRNA and its processing system are virtually conserved in all living organisms, this method could be broadly used to boost the targeting capability and editing efficiency of CRISPR/Cas9 toolkits.

  16. Using Boosting Decision Trees in Gravitational Wave Searches triggered by Gamma-ray Bursts

    NASA Astrophysics Data System (ADS)

    Zuraw, Sarah; LIGO Collaboration

    2015-04-01

    The search for gravitational wave bursts requires the ability to distinguish weak signals from background detector noise. Gravitational wave bursts are characterized by their transient nature, making them particularly difficult to detect as they are similar to non-Gaussian noise fluctuations in the detector. The Boosted Decision Tree method is a powerful machine learning algorithm which uses Multivariate Analysis techniques to explore high-dimensional data sets in order to distinguish between gravitational wave signal and background detector noise. It does so by training with known noise events and simulated gravitational wave events. The method is tested using waveform models and compared with the performance of the standard gravitational wave burst search pipeline for Gamma-ray Bursts. It is shown that the method is able to effectively distinguish between signal and background events under a variety of conditions and over multiple Gamma-ray Burst events. This example demonstrates the usefulness and robustness of the Boosted Decision Tree and Multivariate Analysis techniques as a detection method for gravitational wave bursts. LIGO, UMass, PREP, NEGAP.

  17. Coronary artery disease detection using a fuzzy-boosting PSO approach.

    PubMed

    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.

  18. Broadband up-conversion at subsolar irradiance: triplet-triplet annihilation boosted by fluorescent semiconductor nanocrystals.

    PubMed

    Monguzzi, A; Braga, D; Gandini, M; Holmberg, V C; Kim, D K; Sahu, A; Norris, D J; Meinardi, F

    2014-11-12

    Conventional solar cells exhibit limited efficiencies in part due to their inability to absorb the entire solar spectrum. Sub-band-gap photons are typically lost but could be captured if a material that performs up-conversion, which shifts photon energies higher, is coupled to the device. Recently, molecular chromophores that undergo triplet-triplet annihilation (TTA) have shown promise for efficient up-conversion at low irradiance, suitable for some types of solar cells. However, the molecular systems that have shown the highest up-conversion efficiency to date are ill suited to broadband light harvesting, reducing their applicability. Here we overcome this limitation by combining an organic TTA system with highly fluorescent CdSe semiconductor nanocrystals. Because of their broadband absorption and spectrally narrow, size-tunable fluorescence, the nanocrystals absorb the radiation lost by the TTA chromophores, returning this energy to the up-converter. The resulting nanocrystal-boosted system shows a doubled light-harvesting ability, which allows a green-to-blue conversion efficiency of ∼12.5% under 0.5 suns of incoherent excitation. This record efficiency at subsolar irradiance demonstrates that boosting the TTA by light-emitting nanocrystals can potentially provide a general route for up-conversion for different photovoltaic and photocatalytic applications.

  19. 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.

  20. Regeneration-associated macrophages: a novel approach to boost intrinsic regenerative capacity for axon regeneration.

    PubMed

    Kwon, Min Jung; Yoon, Hyuk Jun; Kim, Byung Gon

    2016-09-01

    Axons in central nervous system (CNS) do not regenerate spontaneously after injuries such as stroke and traumatic spinal cord injury. Both intrinsic and extrinsic factors are responsible for the regeneration failure. Although intensive research efforts have been invested on extrinsic regeneration inhibitors, the extent to which glial inhibitors contribute to the regeneration failure in vivo still remains elusive. Recent experimental evidence has rekindled interests in intrinsic factors for the regulation of regeneration capacity in adult mammals. In this review, we propose that activating macrophages with pro-regenerative molecular signatures could be a novel approach for boosting intrinsic regenerative capacity of CNS neurons. Using a conditioning injury model in which regeneration of central branches of dorsal root ganglia sensory neurons is enhanced by a preceding injury to the peripheral branches, we have demonstrated that perineuronal macrophages surrounding dorsal root ganglia neurons are critically involved in the maintenance of enhanced regeneration capacity. Neuron-derived chemokine (C-C motif) ligand 2 (CCL2) seems to mediate neuron-macrophage interactions conveying injury signals to perineuronal macrophages taking on a soley pro-regenerative phenotype, which we designate as regeneration-associated macrophages (RAMs). Manipulation of the CCL2 signaling could boost regeneration potential mimicking the conditioning injury, suggesting that the chemokine-mediated RAM activation could be utilized as a regenerative therapeutic strategy for CNS injuries.

  1. 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.

  2. Boosted structured additive regression for Escherichia coli fed-batch fermentation modeling.

    PubMed

    Melcher, Michael; Scharl, Theresa; Luchner, Markus; Striedner, Gerald; Leisch, Friedrich

    2017-02-01

    The quality of biopharmaceuticals and patients' safety are of highest priority and there are tremendous efforts to replace empirical production process designs by knowledge-based approaches. Main challenge in this context is that real-time access to process variables related to product quality and quantity is severely limited. To date comprehensive on- and offline monitoring platforms are used to generate process data sets that allow for development of mechanistic and/or data driven models for real-time prediction of these important quantities. Ultimate goal is to implement model based feed-back control loops that facilitate online control of product quality. In this contribution, we explore structured additive regression (STAR) models in combination with boosting as a variable selection tool for modeling the cell dry mass, product concentration, and optical density on the basis of online available process variables and two-dimensional fluorescence spectroscopic data. STAR models are powerful extensions of linear models allowing for inclusion of smooth effects or interactions between predictors. Boosting constructs the final model in a stepwise manner and provides a variable importance measure via predictor selection frequencies. Our results show that the cell dry mass can be modeled with a relative error of about ±3%, the optical density with ±6%, the soluble protein with ±16%, and the insoluble product with an accuracy of ±12%. Biotechnol. Bioeng. 2017;114: 321-334. © 2016 Wiley Periodicals, Inc.

  3. Hypofractionated Proton Boost Combined with External Beam Radiotherapy for Treatment of Localized Prostate Cancer

    PubMed Central

    Johansson, Silvia; Åström, Lennart; Sandin, Fredrik; Isacsson, Ulf; Montelius, Anders; Turesson, Ingela

    2012-01-01

    Proton boost of 20 Gy in daily 5 Gy fractions followed by external beam radiotherapy (EBRT) of 50 Gy in daily 2 Gy fractions were given to 278 patients with prostate cancer with T1b to T4N0M0 disease. Fifty-three percent of the patients received neoadjuvant androgen deprivation therapy (N-ADT). The medium followup was 57 months. The 5-year PSA progression-free survival was 100%, 95%, and 74% for low-, intermediate-, and high-risk patients, respectively. The toxicity evaluation was supported by a patient-reported questionnaire before every consultant visit. Cumulative probability and actuarial prevalence of genitourinary (GU) and gastrointestinal (GI) toxicities are presented according to the RTOG classification. N-ADT did not influence curability. Mild pretreatment GU-symptoms were found to be a strong predictive factor for GU-toxicity attributable to treatment. The actuarial prevalence declined over 3 to 5 years for both GU and GI toxicities, indicating slow resolution of epithelial damage to the genitourinary and gastrointestinal tract. Bladder toxicities rather than gastrointestinal toxicities seem to be dose limiting. More than 5-year followup is necessary to reveal any sign of true progressive late side effects of the given treatment. Hypofractionated proton-boost combined with EBRT is associated with excellent curability of localized PC and acceptable frequencies of treatment toxicity. PMID:22848840

  4. 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.

  5. Boosted event topologies from TeV scale light quark composite partners

    NASA Astrophysics Data System (ADS)

    Backović, Mihailo; Flacke, Thomas; Kim, Jeong Han; Lee, Seung J.

    2015-04-01

    We propose a new search strategy for quark partners which decay into a boosted Higgs and a light quark. As an example, we consider phenomenologically viable right handed up-type quark partners of mass ˜ 1 TeV in composite pseudo-Nambu-Goldstone-boson Higgs models within the context of flavorful naturalness. Our results show that S/B > 1 and signal significance of ˜ 7σ is achievable at TeV LHC with 35 fb-1 of integrated luminosity, sufficient to claim discovery of a new particle. A combination of a multi-dimensional boosted Higgs tagging technique, kinematics of pair produced heavy objects and b-tagging serves to efficiently diminish the large QCD backgrounds while maintaining adequate levels of signal efficiency. We present the analysis in the context of effective field theory, such that our results can be applied to any future search for pair produced vector-like quarks with decay modes to Higgs and a light jet.

  6. 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

  7. Planning of Ir-192 seed implants for boost irradiation to the breast

    SciTech Connect

    Zwicker, R.D.; Schmidt-Ullrich, R.; Schiller, B.

    1985-12-01

    The conservative management of early stage breast cancer with tumor excision and irradiation of the breast is becoming increasingly accepted as an alternative to modified radical mastectomy. The radiotherapy typically consists of 45 to 50 Gy delivered with external beam irradiation, followed by boost irradiation of 15 to 20 Gy to the tumor bed using electron beams or interstitial implantation. Pathological evaluation of the excised tumor, clinical assessment, and mammography are used to determine the tissue volume potentially containing a residual tumor burden and therefore requiring boost irradiation. In this paper we describe planning and implantation procedures for Quimby-type breast implants using Ir-192 seeds encapsulated in nylon tubing. This system deviates in several important respects from the requirements of the standard brachytherapy systems. For double-plane implants, optimized values of the interplanar spacing are given for a range of implant sizes, along with the corresponding target dose rates for 1.0 mCi seeds. We also describe a modification of the angiocatheter implantation technique, which allows the radioactive sources to be secured in place by a magnetic cap and washer, thus greatly facilitating the removal of the sources at the end of treatment.

  8. Boosted Higgs bosons from chromomagnetic b 's: b b ¯h at high luminosity

    NASA Astrophysics Data System (ADS)

    Bramante, Joseph; Delgado, Antonio; Lehman, Landon; Martin, Adam

    2016-03-01

    This paper examines detection prospects and constraints on the chromomagnetic dipole operator for the bottom quark. This operator has a flavor, chirality and Lorentz structure that is distinct from other dimension-6 operators considered in Higgs coupling studies. Its nonstandard Lorentz structure results in boosted b b ¯h events, providing a rate-independent signal of new physics. To date, we find this operator is unconstrained by p p →h +jets and p p →b ¯b searches: for order-1 couplings the permitted cutoff Λ for this operator can be as low as Λ ˜1 TeV . We show how to improve this bound with collider cuts that allow a b -tagged Higgs-plus-dijet search in the Higgs-to-diphoton decay channel to exclude cutoffs as high as ˜6 TeV at 2 σ with 3 ab-1 of luminosity at the 14 TeV LHC. Cuts on the pT of the Higgs are key to this search, because the chromomagnetic dipole yields a nonstandard fraction of boosted Higgses.

  9. 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.

  10. Boosting the Direct CP Measurement of the Higgs-Top Coupling.

    PubMed

    Buckley, Matthew R; Gonçalves, Dorival

    2016-03-04

    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.

  11. High-dose-rate brachytherapy boost for prostate cancer: rationale and technique.

    PubMed

    Morton, Gerard C

    2014-10-01

    High-dose-rate brachytherapy (HDR) is a method of conformal dose escalation to the prostate. It can be used as a local boost in combination with external beam radiotherapy, with a high degree of efficacy and low rate of long term toxicity. Data consistently reports relapse free survival rates of greater than 90% for intermediate risk patients and greater than 80% for high risk. Results are superior to those achieved with external beam radiotherapy alone. A wide range of dose and fractionation is reported, however, we have found that a single 15 Gy HDR combined with hypofractionated radiotherapy to a dose of 37.5 Gy in 15 fractions is well tolerated and is associated with a long term relapse-free survival of over 90%. Either CT-based or trans-rectal ultrasound-based planning may be used. The latter enables treatment delivery without having to move the patient with risk of catheter displacement. We have found it to be an efficient and quick method of treatment, allowing catheter insertion, planning, and treatment delivery to be completed in less than 90 minutes. High-dose-rate boost should be considered the treatment of choice for many men with high and intermediate risk prostate cancer.

  12. Boosting the charged Higgs search prospects using jet substructure at the LHC

    NASA Astrophysics Data System (ADS)

    Li, Jinmian; Patrick, Riley; Sharma, Pankaj; Williams, Anthony G.

    2016-11-01

    Charged Higgs bosons are predicted in variety of theoretically well-motivated new physics models with extended Higgs sectors. In this study, we focus on a type-II two Higgs doublet model (2HDM-II) and consider a heavy charged Higgs with its mass ranging from 500 GeV to 1 TeV as dictated by the b → sγ constraints which render M H ± > 480 GeV. We study the dominant production mode H ± t associated production with H ± → W ± A being the dominant decay channel when the pseudoscalar A is considerably lighter. For such a heavy charged Higgs, both the decay products W ± and A are relatively boosted. In such a scenario, we apply the jet substructure analysis of tagging the fat pseudoscalar and W jets in order to eliminate the standard model background efficiently. We perform a detailed detector simulation for the signal and background processes at the 14 TeV LHC. We introduce various kinematical cuts to determine the signal significance for a number of benchmark points with charged Higgs boson mass from 500 GeV to 1 TeV in the W ± A decay channel. Finally we perform a multivariate analysis utilizing a boosted decision tree algorithm to optimize these significances.

  13. 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.

  14. The Usage of Rusboost Boosting Method for Classification of Impervious Surfaces

    NASA Astrophysics Data System (ADS)

    Kesikoglu, M. H.; Atasever, U. H.; Ozkan, C.; Besdok, E.

    2016-10-01

    Impervious surface areas are artificial structures covered by materials such as asphalt, stone, brick, rooftops and concrete. Buildings, parking lots, roads, driveways and sidewalks are shown as impervious surfaces. They increase depending on the population growth. The spatial development of impervious surface expansion is necessary for better understanding of the urbanization status and its effect on environment. There are different impervious surface determining approaches met in literature. In this paper, it is aimed to extract the impervious surface areas of Kayseri city, Turkey by using remote sensing techniques. It is possible to group these techniques under a few main topics as V-I-S (vegetation-impervious surface-soil) model, based on spectral mixture analysis or decision tree algorithms or impervious surface indices. According to these techniques, we proposed a new technique by using RUSBoost algorithm based on decision tree in this study. In this scope, Landsat 8 LDCM image belonging to July, 2013 was used. Determining of impervious surface areas accurately depends on accuracy of image classification methods. Therefore, satellite image was classified separately by using Classification Tree and RUSBoost boosting method which increases accuracy of the classification method based on decision tree. Classification accuracies of these supervised classification methods were compared and it was observed that the best overall accuracy was obtained with RUSBoost method. For this reason, RUSBoost method was preferred to determine impervious surface areas. The overall accuracies were obtained 95 % with Classification Tree and 97 % with RUSBoost boosting method.

  15. Regeneration-associated macrophages: a novel approach to boost intrinsic regenerative capacity for axon regeneration

    PubMed Central

    Kwon, Min Jung; Yoon, Hyuk Jun; Kim, Byung Gon

    2016-01-01

    Axons in central nervous system (CNS) do not regenerate spontaneously after injuries such as stroke and traumatic spinal cord injury. Both intrinsic and extrinsic factors are responsible for the regeneration failure. Although intensive research efforts have been invested on extrinsic regeneration inhibitors, the extent to which glial inhibitors contribute to the regeneration failure in vivo still remains elusive. Recent experimental evidence has rekindled interests in intrinsic factors for the regulation of regeneration capacity in adult mammals. In this review, we propose that activating macrophages with pro-regenerative molecular signatures could be a novel approach for boosting intrinsic regenerative capacity of CNS neurons. Using a conditioning injury model in which regeneration of central branches of dorsal root ganglia sensory neurons is enhanced by a preceding injury to the peripheral branches, we have demonstrated that perineuronal macrophages surrounding dorsal root ganglia neurons are critically involved in the maintenance of enhanced regeneration capacity. Neuron-derived chemokine (C-C motif) ligand 2 (CCL2) seems to mediate neuron-macrophage interactions conveying injury signals to perineuronal macrophages taking on a soley pro-regenerative phenotype, which we designate as regeneration-associated macrophages (RAMs). Manipulation of the CCL2 signaling could boost regeneration potential mimicking the conditioning injury, suggesting that the chemokine-mediated RAM activation could be utilized as a regenerative therapeutic strategy for CNS injuries. PMID:27857723

  16. The Adaptive Optics Summer School Laboratory Activities

    NASA Astrophysics Data System (ADS)

    Ammons, S. M.; Severson, S.; Armstrong, J. D.; Crossfield, I.; Do, T.; Fitzgerald, M.; Harrington, D.; Hickenbotham, A.; Hunter, J.; Johnson, J.; Johnson, L.; Li, K.; Lu, J.; Maness, H.; Morzinski, K.; Norton, A.; Putnam, N.; Roorda, A.; Rossi, E.; Yelda, S.

    2010-12-01

    Adaptive Optics (AO) is a new and rapidly expanding field of instrumentation, yet astronomers, vision scientists, and general AO practitioners are largely unfamiliar with the root technologies crucial to AO systems. The AO Summer School (AOSS), sponsored by the Center for Adaptive Optics, is a week-long course for training graduate students and postdoctoral researchers in the underlying theory, design, and use of AO systems. AOSS participants include astronomers who expect to utilize AO data, vision scientists who will use AO instruments to conduct research, opticians and engineers who design AO systems, and users of high-bandwidth laser communication systems. In this article we describe new AOSS laboratory sessions implemented in 2006-2009 for nearly 250 students. The activity goals include boosting familiarity with AO technologies, reinforcing knowledge of optical alignment techniques and the design of optical systems, and encouraging inquiry into critical scientific questions in vision science using AO systems as a research tool. The activities are divided into three stations: Vision Science, Fourier Optics, and the AO Demonstrator. We briefly overview these activities, which are described fully in other articles in these conference proceedings (Putnam et al., Do et al., and Harrington et al., respectively). We devote attention to the unique challenges encountered in the design of these activities, including the marriage of inquiry-like investigation techniques with complex content and the need to tune depth to a graduate- and PhD-level audience. According to before-after surveys conducted in 2008, the vast majority of participants found that all activities were valuable to their careers, although direct experience with integrated, functional AO systems was particularly beneficial.

  17. Inclusion of a CRF01_AE HIV envelope protein boost with a DNA/MVA prime-boost vaccine: Impact on humoral and cellular immunogenicity and viral load reduction after SHIV-E challenge.

    PubMed

    Cox, Josephine H; Ferrari, Maria G; Earl, Patricia; Lane, James R; Jagodzinski, Linda L; Polonis, Victoria R; Kuta, Ellen G; Boyer, Jean D; Ratto-Kim, Silvia; Eller, Leigh-Anne; Pham, Doan-Trang; Hart, Lydia; Montefiori, David; Ferrari, Guido; Parrish, Stephanie; Weiner, David B; Moss, Bernard; Kim, Jerome H; Birx, Deborah; VanCott, Thomas C

    2012-02-27

    The current study assessed the immunogenicity and protective efficacy of various prime-boost vaccine regimens in rhesus macaques using combinations of recombinant DNA (rDNA), recombinant MVA (rMVA), and subunit gp140 protein. The rDNA and rMVA vectors were constructed to express Env from HIV-1 subtype CRF01_AE and Gag-Pol from CRF01_AE or SIVmac 239. One of the rMVAs, MVA/CMDR, has been recently tested in humans. Immunizations were administered at months 0 and 1 (prime) and months 3 and 6 (boost). After priming, HIV env-specific serum IgG was detected in monkeys receiving gp140 alone or rMVA but not in those receiving rDNA. Titers were enhanced in these groups after boosting either with gp140 alone or with rMVA plus gp140. The groups that received the rDNA prime developed env-specific IgG after boosting with rMVA with or without gp140. HIV Env-specific serum IgG binding antibodies were elicited more frequently and of higher titer, and breadth of neutralizing antibodies was increased with the inclusion of the subunit Env boost. T cell responses were measured by tetramer binding to Gag p11c in Mamu-A*01 macaques, and by IFN-γ ELISPOT assay to SIV-Gag. T cell responses were induced after vaccination with the highest responses seen in macaques immunized with rDNA and rMVA. Macaques were challenged intravenously with a novel SHIV-E virus (SIVmac239 Gag-Pol with an HIV-1 subtype E-Env CAR402). Post challenge with SHIV-E, antibody titers were boosted in all groups and peaked at 4 weeks. Robust T cell responses were seen in all groups post challenge and in macaques immunized with rDNA and rMVA a clear boosting of responses was seen. A greater than two-log drop in RNA copies/ml at peak viremia and earlier set point was achieved in macaques primed with rDNA, and boosted with rMVA/SHIV-AE plus gp140. Post challenge viremia in macaques immunized with other regimens was not significantly different to that of controls. These results demonstrate that a gp140 subunit and

  18. 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...

  19. On Teaching Adaptively

    ERIC Educational Resources Information Center

    Corno, Lyn

    2008-01-01

    New theory on adaptive teaching reflects the social dynamics of classrooms to explain what practicing teachers do to address student differences related to learning. In teaching adaptively, teachers respond to learners as they work. Teachers read student signals to diagnose needs on the fly and tap previous experience with similar learners to…

  20. Computerized Adaptive Ability Measurement.

    ERIC Educational Resources Information Center

    Weiss, David J.

    The general objective of a research program on adaptive testing was to identify several sources of potential error in test scores, and to study adaptive testing as a means for reducing these errors. Errors can result from the mismatch of item difficulty to the individual's ability; the psychological effects of testing and the test environment; the…

  1. 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).

  2. 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.

  3. 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…

  4. Adaptive Wavelet Transforms

    SciTech Connect

    Szu, H.; Hsu, C.

    1996-12-31

    Human sensors systems (HSS) may be approximately described as an adaptive or self-learning version of the Wavelet Transforms (WT) that are capable to learn from several input-output associative pairs of suitable transform mother wavelets. Such an Adaptive WT (AWT) is a redundant combination of mother wavelets to either represent or classify inputs.

  5. 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

  6. 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

  7. 75 FR 57859 - Specially Adapted Housing and Special Home Adaptation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-23

    ... AFFAIRS 38 CFR Part 3 RIN 2900-AN21 Specially Adapted Housing and Special Home Adaptation AGENCY... housing and special home adaptation grants. This final rule incorporates certain provisions from the... adapted housing (SAH) grants and special home adaptation (SHA) grants. The public comment period ended...

  8. Financing climate change adaptation.

    PubMed

    Bouwer, Laurens M; Aerts, Jeroen C J H

    2006-03-01

    This paper examines the topic of financing adaptation in future climate change policies. A major question is whether adaptation in developing countries should be financed under the 1992 United Nations Framework Convention on Climate Change (UNFCCC), or whether funding should come from other sources. We present an overview of financial resources and propose the employment of a two-track approach: one track that attempts to secure climate change adaptation funding under the UNFCCC; and a second track that improves mainstreaming of climate risk management in development efforts. Developed countries would need to demonstrate much greater commitment to the funding of adaptation measures if the UNFCCC were to cover a substantial part of the costs. The mainstreaming of climate change adaptation could follow a risk management path, particularly in relation to disaster risk reduction. 'Climate-proofing' of development projects that currently do not consider climate and weather risks could improve their sustainability.

  9. DNA vaccination by electroporation and boosting with recombinant proteins enhances the efficacy of DNA vaccines for Schistosomiasis japonica.

    PubMed

    Dai, Yang; Zhu, Yinchang; Harn, Donald A; Wang, Xiaoting; Tang, Jianxia; Zhao, Song; Lu, Fei; Guan, Xiaohong

    2009-12-01

    Schistosomiasis japonica is an endemic, zoonotic disease of major public health importance in China. Control programs combining chemotherapy and snail killing have not been able to block transmission of infection in lakes and marsh regions. Vaccination is needed as a complementary approach to the ongoing control programs. In the present study, we wanted to determine if the efficacies of DNA vaccines encoding the 23-kDa tetraspanin membrane protein (SjC23), triose phosphate isomerase (SjCTPI), and sixfold-repeated genes of the complementarity determining region 3 (CDR3) in the H chain of NP30 could be enhanced by boosting via electroporation in vivo and/or with cocktail protein vaccines. Mice vaccinated with cocktail DNA vaccines showed a significant worm reduction of 32.88% (P < 0.01) and egg reduction of 36.20% (P < 0.01). Vaccine efficacy was enhanced when animals were boosted with cocktail protein vaccines; adult worm and liver egg burdens were reduced 45.35% and 48.54%, respectively. Nearly identical results were obtained in mice boosted by electroporation in vivo, with adult worm and egg burdens reduced by 45.00% and 50.88%, respectively. The addition of a protein vaccine boost to this regimen further elevated efficacy to approximately 60% for adult worm burden and greater than 60% for liver egg reduction. The levels of interleukin-2, gamma interferon, and the ratios of immunoglobulin G2a (IgG2a)/IgG1 clearly showed that cocktail DNA vaccines induced CD4(+) Th1-type responses. Boosting via either electroporation or with recombinant proteins significantly increased associated immune responses over those seen in mice vaccinated solely with DNA vaccines. Thus, schistosome DNA vaccine efficacy was significantly enhanced via boosting by electroporation in vivo and/or cocktail protein vaccines.

  10. Modeling and dynamics analysis of the fractional-order Buck—Boost converter in continuous conduction mode

    NASA Astrophysics Data System (ADS)

    Yang, Ning-Ning; Liu, Chong-Xin; Wu, Chao-Jun

    2012-08-01

    In this paper, the fractional-order mathematical model and the fractional-order state-space averaging model of the Buck—Boost converter in continuous conduction mode (CCM) are established based on the fractional calculus and the Adomian decomposition method. Some dynamical properties of the current-mode controlled fractional-order Buck—Boost converter are analysed. The simulation is accomplished by using SIMULINK. Numerical simulations are presented to verify the analytical results and we find that bifurcation points will be moved backward as α and β vary. At the same time, the simulation results show that the converter goes through different routes to chaos.

  11. Input Voltage Loop Control with AC Current Feedback for Buck Boost Regulators (B2R) Used as Solar Array Regulators

    NASA Astrophysics Data System (ADS)

    Mourra, Olivier; Fernandez, Arturo; Tonicello, Ferdinando

    2014-08-01

    In a satellite, the main function of a Power Conditioning Unit is to manage the energy coming from several power sources (usually solar arrays and battery) and to deliver it continuously to the users in an appropriate form during the overall mission. Solar Array Regulators are used to extract the power from the SA in order to recharge the battery and to supply the loads during sunlight. The objective of this paper is to present a control technique that can be used when segregated buck, boost or buck boost SAR are implemented. The paper demonstrate theoretically and experimentally the feasibility of this technique.

  12. Applying additive modeling and gradient boosting to assess the effects of watershed and reach characteristics on riverine assemblages

    USGS Publications Warehouse

    Maloney, Kelly O.; Schmid, Matthias; Weller, Donald E.

    2012-01-01

    Issues with ecological data (e.g. non-normality of errors, nonlinear relationships and autocorrelation of variables) and modelling (e.g. overfitting, variable selection and prediction) complicate regression analyses in ecology. Flexible models, such as generalized additive models (GAMs), can address data issues, and machine learning techniques (e.g. gradient boosting) can help resolve modelling issues. Gradient boosted GAMs do both. Here, we illustrate the advantages of this technique using data on benthic macroinvertebrates and fish from 1573 small streams in Maryland, USA.

  13. 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

  14. 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.

  15. Creating Diverse Ensemble Classifiers to Reduce Supervision

    DTIC Science & Technology

    2005-12-01

    Bauer & Kohavi, 1999; McDonald et al., 2002), and several variations of AdaBoost have been developed to address this issue. For example, Kalai and...International Conference on Information and Knowledge Manage- ment, pp. 70–77, McLean, US. ACM Press, New York, US. Kalai , A., & Servedio, R. A. (2003). Boosting

  16. Adaptation to blur

    NASA Astrophysics Data System (ADS)

    Webster, Michael A.; Webster, Shernaaz M.; MacDonald, Jennifer; Bahradwadj, Shrikant R.

    2001-06-01

    Blur is an intrinsic property of the retinal image that can vary substantially in natural viewing. We examined how processes of contrast adaptation might adjust the visual system to regulate the perception of blur. Observers viewed a blurred or sharpened image for 2-5 minutes, and then judged the apparent focus of a series of 0.5-sec test images interleaved with 6-sec of readaptation. A 2AFC staircase procedure was used to vary the amplitude spectrum of successive test to find the image that appeared in focus. Adapting to a blurred image causes a physically focused image to appear too sharp. Opposite after-effects occur for sharpened adapting images. Pronounced biases were observed over a wide range of magnitudes of adapting blur, and were similar for different types of blur. After-effects were also similar for different classes of images but were generally weaker when the adapting and test stimuli were different images, showing that the adaptation is not adjusting simply to blur per se. These adaptive adjustments may strongly influence the perception of blur in normal vision and how it changes with refractive errors.

  17. Concomitant cervical and transperineal parametrial high-dose-rate brachytherapy boost for locally advanced cervical cancer

    PubMed Central

    Bailleux, Caroline; Falk, Alexander Tuan; Chand-Fouche, Marie-Eve; Gautier, Mathieu; Barranger, Emmanuel

    2016-01-01

    Purpose There is no consensus for parametrial boost technic while both transvaginal and transperineal approaches are discussed. A prototype was developed consisting of a perineal template, allowing transperineal needle insertion. This study analyzed acute toxicity of concomitant cervical and transperineal parametrial high-dose-rate brachytherapy (HDRB) boost for locally advanced cervical cancer. Material and methods From 01.2011 to 12.2014, 33 patients (pts) presenting a locally advanced cervical cancer with parametrial invasion were treated. After the first course of external beam radiation therapy with cisplatinum, HDRB was performed combining endocavitary and interstitial technique for cervical and parametrial disease. Post-operative delineation (CTV, bladder, rectum, sigmoid) and planification were based on CT-scan/MRI. HDRB was delivered in 3-5 fractions over 2-3 consecutive days. Acute toxicities occurring within 6 months after HDRB were retrospectively reviewed. Results Median age was 56.4 years (27-79). Clinical stages were: T2b = 23 pts (69.7%), T3a = 1 pt (3%), T3b = 6 pts (18.2%), and T4a = 3 pts (9.1%). Median HDRB prescribed dose was 21 Gy (21-27). Median CTVCT (16 pts) and HR-CTVMRI (17 pts) were 52.6 cc (28.5-74.3), 31.9 cc (17.1-58), respectively. Median EQD2αβ10 for D90CTV and D90HR-CTV were 82.9 Gy (78.2-96.5), 84.8 Gy (80.6-91.4), respectively. Median EQD2αβ3 (CT/MRI) for D2cc bladder, rectum and sigmoid were 75.5 Gy (66.6-90.9), 64.4 Gy (51.9-77.4), and 60.4 Gy (50.9-81.1), respectively. Median follow-up was 14 months (ranged 6-51). Among the 24 pts with MFU = 24 months, 2-year LRFS rate, RRFS, and OS were 86.8%, 88.8%, and 94.1%, respectively. The rates of acute genitourinary and gastrointestinal toxicities were 36% (G1 dysuria = 8 pts, G2 infection = 2 pts, G3 infection = 2 pts), and 27% (G1 diarrhea = 9 pts), respectively. One patient presented vaginal bleeding at the time of applicator withdrawal (G3-blood transfusion); no bleeding was

  18. Hypofractionated Concomitant Intensity-Modulated Radiotherapy Boost for High-Risk Prostate Cancer: Late Toxicity

    SciTech Connect

    Quon, Harvey; Cheung, Patrick C.F.; Loblaw, D. Andrew; Morton, Gerard; Pang, Geordi; Szumacher, Ewa; Danjoux, Cyril; Choo, Richard; Thomas, Gillian; Kiss, Alex; Mamedov, Alexandre; Deabreu, Andrea

    2012-02-01

    Purpose: To report the acute and late toxicities of patients with high-risk localized prostate cancer treated using a concomitant hypofractionated, intensity-modulated radiotherapy boost combined with long-term androgen deprivation therapy. Methods and Materials: A prospective Phase I-II study of patients with any of the following: clinical Stage T3 disease, prostate-specific antigen level {>=}20 ng/mL, or Gleason score 8-10. A dose of 45 Gy (1.8 Gy/fraction) was delivered to the pelvic lymph nodes with a concomitant 22.5 Gy prostate intensity-modulated radiotherapy boost, to a total of 67.5 Gy (2.7 Gy/fraction) in 25 fractions within 5 weeks. Image guidance was performed using three gold seed fiducials. The National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0, and Radiation Therapy Oncology Group late morbidity scores were used to assess the acute and late toxicities, respectively. Biochemical failure was determined using the Phoenix definition. Results: A total of 97 patients were treated and followed up for a median of 39 months, with 88% having a minimum of 24 months of follow-up. The maximal toxicity scores were recorded. The grade of acute gastrointestinal toxicity was Grade 0 in 4%, 1 in 59%, and 2 in 37%. The grade of acute urinary toxicity was Grade 0 in 8%, 1 in 50%, 2 in 39%, and 3 in 4%. The grade of late gastrointestinal toxicity was Grade 0 in 54%, 1 in 40%, and 2 in 7%. No Grade 3 or greater late gastrointestinal toxicities developed. The grade of late urinary toxicity was Grade 0 in 82%, 1 in 9%, 2 in 5%, 3 in 3%, and 4 in 1% (1 patient). All severe toxicities (Grade 3 or greater) had resolved at the last follow-up visit. The 4-year biochemical disease-free survival rate was 90.5%. Conclusions: A hypofractionated intensity-modulated radiotherapy boost delivering 67.5 Gy in 25 fractions within 5 weeks combined with pelvic nodal radiotherapy and long-term androgen deprivation therapy was well tolerated, with low rates

  19. Whole-Field Simultaneous Integrated-Boost Intensity-Modulated Radiotherapy for Patients With Nasopharyngeal Carcinoma

    SciTech Connect

    Wong, Frank C.S.; Ng, Alice W.Y.; Lee, Victor H.F.; Lui, Collin M.M.; Yuen, K.-K.; Sze, W.-K.; Leung, T.-W.; Tung, Stewart Y.

    2010-01-15

    Purpose: To retrospectively review the outcomes of our patients with newly diagnosed nondisseminated nasopharyngeal carcinoma treated with intensity-modulated radiotherapy using a whole-field simultaneous integrated-boost technique. Methods and Materials: A total of 175 patients treated with WF-SIB between mid-2004 and 2005 were eligible for study inclusion. The distribution of disease by stage was Stage IA in 10.9%, Stage IIA in 2.3%, Stage IIB in 21.7%, Stage III in 41.1%, Stage IVA in 14.9%, and Stage IVB in 9.1%. Of the 175 patients, 2 (1.2%), 10 (5.7%), and 163 (93.1%) had World Health Organization type I, II, and III histologic features, respectively. We prescribed 70 Gy, 60 Gy, and 54 Gy delivered in 33 fractions within 6.5 weeks at the periphery of three planning target volumes (PTV; PTV70, PTV60, and PTV54, respectively). Of the 175 patients, 46 with early T-stage disease received a brachytherapy boost, and 127 with advanced local or regional disease received chemotherapy. Results: The median follow-up period was 34 months. The overall 3-year local failure-free survival, regional failure-free survival, distant failure-free survival, and overall survival rate was 93.6%, 93.3%, 86.6%, and 87.2%, respectively. Cox regression analysis showed Stage N2-N3 disease (p = .029) and PTV (p = .024) to be independent factors predicting a greater risk of distant failure and poor overall survival, respectively. Grade 3 acute mucositis/pharyngitis occurred in 23.4% of patients, and Stage T4 disease was the only significant predictor of mucositis/pharyngitis (p = .021). Conclusion: Whole-field simultaneous integrated-boost intensity-modulated radiotherapy with a dose >70 Gy achieved excellent locoregional control, without an excess incidence of severe, acute mucositis/pharyngitis, in the present study. Strategies for using such highly conformal treatment for patients with a large tumor and late N-stage disease are potential areas of investigation for future studies.

  20. [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.

  1. 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.

  2. Adaptive optics ophthalmoscopy.

    PubMed

    Roorda, A

    2000-01-01

    Retinal images in the human eye are normally degraded because we are forced to use the optical system of the human eye--which is fraught with aberrations--as the objective lens. The recent application of adaptive optics technology to measure and compensate for these aberrations has produced retinal images in human eyes with unprecedented resolution. The adaptive optics ophthalmoscope is used to take pictures of photoreceptors and capillaries and to study spectral and angular tuning properties of individual photoreceptors. Application of adaptive optics technology for ophthalmoscopy promises continued progress toward understanding the basic properties of the living human retina and also for clinical applications.

  3. Adaptive Telemetry Multiplexer

    NASA Technical Reports Server (NTRS)

    Sinderson, R. L.; Salazar, G. A.; Haddick, C. M., Jr.; Spahn, C. J.; Venkatesh, C. N.

    1989-01-01

    Telemetry-data-acquisition unit adjusted remotely to produce changes in sampling rate, sampling channels, measurement scale, and output-bias level. Functional configuration adapted to changing conditions or new requirements by distant operator over telemetry link. Reconfiguration done in real time, without removing equipment from service. Bus-interface unit accepts reprogramming commands and translates them for low-rate adaptive multiplexer. Reprogrammable equipment reduces need for spare parts, since not necessary to stock variety of hardware with fixed characteristics. Adaptive multiplexer performs well in tests, amplitude errors less than 0.5 percent, distortion less than 0.25 percent, and crosstalk and common-mode rejection indiscernible.

  4. Telescope Adaptive Optics Code

    SciTech Connect

    Phillion, D.

    2005-07-28

    The Telescope AO Code has general adaptive optics capabilities plus specialized models for three telescopes with either adaptive optics or active optics systems. It has the capability to generate either single-layer or distributed Kolmogorov turbulence phase screens using the FFT. Missing low order spatial frequencies are added using the Karhunen-Loeve expansion. The phase structure curve is extremely dose to the theoreUcal. Secondly, it has the capability to simulate an adaptive optics control systems. The default parameters are those of the Keck II adaptive optics system. Thirdly, it has a general wave optics capability to model the science camera halo due to scintillation from atmospheric turbulence and the telescope optics. Although this capability was implemented for the Gemini telescopes, the only default parameter specific to the Gemini telescopes is the primary mirror diameter. Finally, it has a model for the LSST active optics alignment strategy. This last model is highly specific to the LSST

  5. 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.

  6. 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)

  7. 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...

  8. Addition of visual noise boosts evoked potential-based brain-computer interface

    PubMed Central

    Xie, Jun; Xu, Guanghua; Wang, Jing; Zhang, Sicong; Zhang, Feng; Li, Yeping; Han, Chengcheng; Li, Lili

    2014-01-01

    Although noise has a proven beneficial role in brain functions, there have not been any attempts on the dedication of stochastic resonance effect in neural engineering applications, especially in researches of brain-computer interfaces (BCIs). In our study, a steady-state motion visual evoked potential (SSMVEP)-based BCI with periodic visual stimulation plus moderate spatiotemporal noise can achieve better offline and online performance due to enhancement of periodic components in brain responses, which was accompanied by suppression of high harmonics. Offline results behaved with a bell-shaped resonance-like functionality and 7–36% online performance improvements can be achieved when identical visual noise was adopted for different stimulation frequencies. Using neural encoding modeling, these phenomena can be explained as noise-induced input-output synchronization in human sensory systems which commonly possess a low-pass property. Our work demonstrated that noise could boost BCIs in addressing human needs. PMID:24828128

  9. Switch failure diagnosis based on inductor current observation for boost converters

    NASA Astrophysics Data System (ADS)

    Jamshidpour, E.; Poure, P.; Saadate, S.

    2016-09-01

    Face to the growing number of applications using DC-DC power converters, the improvement of their reliability is subject to an increasing number of studies. Especially in safety critical applications, designing fault-tolerant converters is becoming mandatory. In this paper, a switch fault-tolerant DC-DC converter is studied. First, some of the fastest Fault Detection Algorithms (FDAs) are recalled. Then, a fast switch FDA is proposed which can detect both types of failures; open circuit fault as well as short circuit fault can be detected in less than one switching period. Second, a fault-tolerant converter which can be reconfigured under those types of fault is introduced. Hardware-In-the-Loop (HIL) results and experimental validations are given to verify the validity of the proposed switch fault-tolerant approach in the case of a single switch DC-DC boost converter with one redundant switch.

  10. Improved boost mirror for low-concentration photovoltaic solar power systems

    NASA Astrophysics Data System (ADS)

    Wells, David N.

    2009-08-01

    A new reflector surface and geometry using low-concentration mirror boosting of flat-plate photo voltaic devices is described. The overheating effects that have previously been seen using non-uniform, high reflectivity side mirrors have been reduced. The new high-stability reflector material has lower UV reflectivity that reduces panel ageing and over heating. A moderate reflectivity in the violet wavelength further cuts the level of overheating while sacrificing only minimally in electrical power output efficiency. The new surface maintains high, uniform reflectivity at green, yellow, red, and IR wavelengths. Mass-produced panels are undergoing tests, and some preliminary results are presented. Surface self-cleaning of hydrophilic and hydrophobic coating over the reflecting surface is also discussed. Other applications of the same mirror in the solar thermal field are briefly discussed. Some improved tracking PV geometry versions using the new material are presented.

  11. Using semantic memory to boost 'episodic' recall in a case of developmental amnesia.

    PubMed

    Brandt, Karen R; Gardiner, John M; Vargha-Khadem, Faraneh; Baddeley, Alan D; Mishkin, Mortimer

    2006-07-17

    We report two experiments that investigated factors that might boost 'episodic' recall for Jon, a developmental amnesic whose episodic memory is gravely impaired but whose semantic memory seems relatively normal. Experiment 1 showed that Jon's recall improved following a semantic study task compared with a non-semantic study task, as well as following four repeated study trials compared with only one. Experiment 2 additionally revealed that Jon's recall improved after acting compared with reading action phrases at study, but only if the phrases were well integrated semantically. The results provide some support for the hypothesis that Jon's 'episodic' recall depends on the extent to which he is able to retrieve events using semantic memory.

  12. Single-Phase Active Boost Rectifier with Power Factor Correction for Wireless Power Transfer Applications

    SciTech Connect

    Chinthavali, Madhu Sudhan; Onar, Omer C; Miller, John M; Tang, Lixin

    2013-01-01

    Wireless Power Transfer (WPT) technology is a novel research area in the charging technology that bridges utility and the automotive industries. There are various solutions that are currently being evaluated by several research teams to find the most efficient way to manage the power flow from the grid to the vehicle energy storage system. There are different control parameters that can be utilized to compensate for the change in the impedance. To understand the power flow through the system this paper presents a novel approach to the system model and the impact of different control parameters on the load power. The implementation of an active front-end rectifier on the grid side for power factor control and voltage boost capability for load power regulation is also discussed.

  13. Boosting the Energy Density of Carbon-Based Aqueous Supercapacitors by Optimizing the Surface Charge.

    PubMed

    Yu, Minghao; Lin, Dun; Feng, Haobin; Zeng, Yinxiang; Tong, Yexiang; Lu, Xihong

    2017-03-27

    The voltage of carbon-based aqueous supercapacitors is limited by the water splitting reaction occurring in one electrode, generally resulting in the promising but unused potential range of the other electrode. Exploiting this unused potential range provides the possibility for further boosting their energy density. An efficient surface charge control strategy was developed to remarkably enhance the energy density of multiscale porous carbon (MSPC) based aqueous symmetric supercapacitors (SSCs) by controllably tuning the operating potential range of MSPC electrodes. The operating voltage of the SSCs with neutral electrolyte was significantly expanded from 1.4 V to 1.8 V after simple adjustment, enabling the energy density of the optimized SSCs reached twice as much as the original. Such a facile strategy was also demonstrated for the aqueous SSCs with acidic and alkaline electrolytes, and is believed to bring insight in the design of aqueous supercapacitors.

  14. Boosted top quark signals for heavy vector boson excitations in a universal extra dimension model

    SciTech Connect

    Bhattacherjee, Biplob; Raychaudhuri, Sreerup; Sridhar, K.; Guchait, Monoranjan

    2010-09-01

    In view of the fact that the n=1 Kaluza-Klein (KK) modes in a model with a universal extra dimension could mimic supersymmetry signatures at the LHC, it is necessary to look for the n=2 KK modes, which have no analogues in supersymmetry. We discuss the possibility of searching for heavy n=2 vector boson resonances--especially the g{sub 2}--through their decays to a highly boosted top quark-antiquark pair using recently developed top-jet tagging techniques in the hadronic channel. It is shown that tt signals from the n=2 gluon resonance are as efficient a discovery mode at the LHC as dilepton channels from the {gamma}{sub 2} and Z{sub 2} resonances.

  15. Optimized MPPT algorithm for boost converters taking into account the environmental variables

    NASA Astrophysics Data System (ADS)

    Petit, Pierre; Sawicki, Jean-Paul; Saint-Eve, Frédéric; Maufay, Fabrice; Aillerie, Michel

    2016-07-01

    This paper presents a study on the specific behavior of the Boost DC-DC converters generally used for powering conversion of PV panels connected to a HVDC (High Voltage Direct Current) Bus. It follows some works pointing out that converter MPPT (Maximum Power Point Tracker) is severely perturbed by output voltage variations due to physical dependency of parameters as the input voltage, the output voltage and the duty cycle of the PWM switching control of the MPPT. As a direct consequence many converters connected together on a same load perturb each other because of the output voltage variations induced by fluctuations on the HVDC bus essentially due to a not insignificant bus impedance. In this paper we show that it is possible to include an internal computed variable in charge to compensate local and external variations to take into account the environment variables.

  16. Divided attention can enhance memory encoding: the attentional boost effect in implicit memory.

    PubMed

    Spataro, Pietro; Mulligan, Neil W; Rossi-Arnaud, Clelia

    2013-07-01

    Distraction during encoding has long been known to disrupt later memory performance. Contrary to this long-standing result, we show that detecting an infrequent target in a dual-task paradigm actually improves memory encoding for a concurrently presented word, above and beyond the performance reached in the full-attention condition. This absolute facilitation was obtained in 2 perceptual implicit tasks (lexical decision and word fragment completion) but not in a conceptual implicit task (semantic classification). In the case of recognition memory, the facilitation was relative, bringing accuracy in the divided attention condition up to the level of accuracy in the full attention condition. The findings follow from the hypothesis that the attentional boost effect reflects enhanced visual encoding of the study stimulus consequent to the transient orienting response to the dual-task target.

  17. Assessment of MCRM Boost Assist from Orbit for Deep Space Missions

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Report provides results of analysis for the beamed energy driven MHD Chemical Rocket Motor (MCRM) for application to boost from orbit to escape for deep space and interplanetary missions. Parametric analyses were performed in the mission to determine operating regime for which the MCRM provides significant propulsion performance enhancement. Analysis of the MHD accelerator was performed numerical computational methods to determine design and operational features necessary to achieve Isp on the order of 2,000 to 3,000 seconds. Algorithms were developed to scale weights for the accelerator and power supply. Significant improvement in propulsion system performance can be achieved with the beamed energy driven MCRM. The limiting factor on achievable vehicle acceleration is the specific power of the rectenna.

  18. Boosted Jet Tagging with Jet-Images and Deep Neural Networks

    NASA Astrophysics Data System (ADS)

    Kagan, Michael; de Oliveira, Luke; Mackey, Lester; Nachman, Benjamin; Schwartzman, Ariel

    2016-11-01

    Building on the jet-image based representation of high energy jets, we develop computer vision based techniques for jet tagging through the use of deep neural networks. Jet-images enabled the connection between jet substructure and tagging with the fields of computer vision and image processing. We show how applying such techniques using deep neural networks can improve the performance to identify highly boosted W bosons with respect to state-of-the-art substructure methods. In addition, we explore new ways to extract and visualize the discriminating features of different classes of jets, adding a new capability to understand the physics within jets and to design more powerful jet tagging methods.

  19. Stereotype boost and stereotype threat effects: the moderating role of ethnic identification.

    PubMed

    Armenta, Brian E

    2010-01-01

    Belonging to a stereotyped social group can affect performance in stereotype-relevant situations, often shifting performance in the direction of the stereotype. This effect occurs similarly for members of positively and negatively stereotyped groups (i.e., stereotype boost and stereotype threat, respectively). This study examined ethnic group identification as a moderator of these effects in the math performance of Asian Americans and Latinos, who are positively and negatively stereotyped in this domain, respectively. Results showed that high ethnically identified Asian Americans performed better and high ethnically identified Latinos performed worse when an ethnicity-ethnic stereotype cue was present. The performance of low ethnically identified Asian Americans and Latinos was not affected by this cue.

  20. Stability of spinning ICBM (intercontinental ballistic missile) in first stage boost phase

    NASA Astrophysics Data System (ADS)

    Bandstra, R. W.

    1985-12-01

    A computer program is developed to model a spinning intercontinental Ballistic Missile (IICBM) during the first stage boost phase. The equations of motion are derived and presented and a full rotation matrix is used to show the relationship between a launch-centered, nonrotating earth inertial reference frame and the missile body reference frame. The moments of inertia and aerodynamic forces are derived and presented. A feedback controller is derived which proved to be a necessary additiion to the system in order to reduce the angle of attack. The angle of attack of the missile produced adverse effects on the burnout vector without the feedback controller, but the effects are reduced considerably with the controller included. Problem areas include possibly excessive nozzle gimbal rates caused by the feedback controller and the need to change the initial kick angle if the missile is spinning in order to achieve the same burnout conditions as a nonspinning missile.