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Sample records for single-pair discrimination learning

  1. Learning discriminant face descriptor.

    Science.gov (United States)

    Lei, Zhen; Pietikäinen, Matti; Li, Stan Z

    2014-02-01

    Local feature descriptor is an important module for face recognition and those like Gabor and local binary patterns (LBP) have proven effective face descriptors. Traditionally, the form of such local descriptors is predefined in a handcrafted way. In this paper, we propose a method to learn a discriminant face descriptor (DFD) in a data-driven way. The idea is to learn the most discriminant local features that minimize the difference of the features between images of the same person and maximize that between images from different people. In particular, we propose to enhance the discriminative ability of face representation in three aspects. First, the discriminant image filters are learned. Second, the optimal neighborhood sampling strategy is soft determined. Third, the dominant patterns are statistically constructed. Discriminative learning is incorporated to extract effective and robust features. We further apply the proposed method to the heterogeneous (cross-modality) face recognition problem and learn DFD in a coupled way (coupled DFD or C-DFD) to reduce the gap between features of heterogeneous face images to improve the performance of this challenging problem. Extensive experiments on FERET, CAS-PEAL-R1, LFW, and HFB face databases validate the effectiveness of the proposed DFD learning on both homogeneous and heterogeneous face recognition problems. The DFD improves POEM and LQP by about 4.5 percent on LFW database and the C-DFD enhances the heterogeneous face recognition performance of LBP by over 25 percent.

  2. Discrimination Learning in Children

    Science.gov (United States)

    Ochocki, Thomas E.; And Others

    1975-01-01

    Examined the learning performance of 192 fourth-, fifth-, and sixth-grade children on either a two or four choice simultaneous color discrimination task. Compared the use of verbal reinforcement and/or punishment, under conditions of either complete or incomplete instructions. (Author/SDH)

  3. Discriminative learning for speech recognition

    CERN Document Server

    He, Xiadong

    2008-01-01

    In this book, we introduce the background and mainstream methods of probabilistic modeling and discriminative parameter optimization for speech recognition. The specific models treated in depth include the widely used exponential-family distributions and the hidden Markov model. A detailed study is presented on unifying the common objective functions for discriminative learning in speech recognition, namely maximum mutual information (MMI), minimum classification error, and minimum phone/word error. The unification is presented, with rigorous mathematical analysis, in a common rational-functio

  4. Learning to Discriminate Face Views

    Directory of Open Access Journals (Sweden)

    Fang Fang

    2011-05-01

    Full Text Available Although visual feature leaning has been well studied, we still know little about the mechanisms of perceptual learning of complex object. Here, human perceptual learning in discrimination of in-depth orientation of face view was studied using psychophysics, EEG and fMRI. We trained subjects to discriminate face orientations around a face view (i.e. 30° over eight daily sessions, which resulted in a significant improvement in sensitivity to the face view orientation. This improved sensitivity was highly specific to the trained orientation and persisted up to six months. Different from perceptual learning of simple visual features, this orientation-specific learning effect could completely transfer across changes in face size, visual field and face identity. A complete transfer also occurred between two partial face images that were mutually exclusive but constituted a complete face. However, the transfer of the learning effect between upright and inverted faces and between a face and a paperclip object was very weak. Before and after training, we measured EEG and fMRI BOLD signals responding to both the trained and the untrained face views. Analyses of ERPs and induced gamma activity showed that face view discrimination training led to a larger reduction of N170 latency at the left occipital-temporal area and a concurrent larger decrease of induced gamma activity at the left frontal area with the trained face view, compared with the untrained ones. BOLD signal amplitude and MVPA analyses showed that, in face-selective cortical areas, training did not lead to a significant amplitude change, but induced a more reliable spatial pattern of neural activity in the left FFA. These results suggest that the visual system had learned how to compute face orientation from face configural information more accurately and that a large amount of plastic changes took place at a level of higher visual processing where size-, location-, and identity

  5. Learning Disability and Ethnic Minority Discrimination.

    Science.gov (United States)

    Drucker, Howard; And Others

    Discrimination is discussed as it applies to the exclusion of racial minorities in classes for children with learning disabilities. The authors contend that this type of racial discrimination is prevalent nationwide (as illustrated by results of a national survey), and that the definition of learning disabilities and how it is operationalized has…

  6. Discrimination learning with variable stimulus 'salience'

    Directory of Open Access Journals (Sweden)

    Treviño Mario

    2011-08-01

    Full Text Available Abstract Background In nature, sensory stimuli are organized in heterogeneous combinations. Salient items from these combinations 'stand-out' from their surroundings and determine what and how we learn. Yet, the relationship between varying stimulus salience and discrimination learning remains unclear. Presentation of the hypothesis A rigorous formulation of the problem of discrimination learning should account for varying salience effects. We hypothesize that structural variations in the environment where the conditioned stimulus (CS is embedded will be a significant determinant of learning rate and retention level. Testing the hypothesis Using numerical simulations, we show how a modified version of the Rescorla-Wagner model, an influential theory of associative learning, predicts relevant interactions between varying salience and discrimination learning. Implications of the hypothesis If supported by empirical data, our model will help to interpret critical experiments addressing the relations between attention, discrimination and learning.

  7. Auditory Discrimination Learning: Role of Working Memory.

    Science.gov (United States)

    Zhang, Yu-Xuan; Moore, David R; Guiraud, Jeanne; Molloy, Katharine; Yan, Ting-Ting; Amitay, Sygal

    2016-01-01

    Perceptual training is generally assumed to improve perception by modifying the encoding or decoding of sensory information. However, this assumption is incompatible with recent demonstrations that transfer of learning can be enhanced by across-trial variation of training stimuli or task. Here we present three lines of evidence from healthy adults in support of the idea that the enhanced transfer of auditory discrimination learning is mediated by working memory (WM). First, the ability to discriminate small differences in tone frequency or duration was correlated with WM measured with a tone n-back task. Second, training frequency discrimination around a variable frequency transferred to and from WM learning, but training around a fixed frequency did not. The transfer of learning in both directions was correlated with a reduction of the influence of stimulus variation in the discrimination task, linking WM and its improvement to across-trial stimulus interaction in auditory discrimination. Third, while WM training transferred broadly to other WM and auditory discrimination tasks, variable-frequency training on duration discrimination did not improve WM, indicating that stimulus variation challenges and trains WM only if the task demands stimulus updating in the varied dimension. The results provide empirical evidence as well as a theoretic framework for interactions between cognitive and sensory plasticity during perceptual experience.

  8. Discriminative Transfer Learning for General Image Restoration

    KAUST Repository

    Xiao, Lei

    2017-03-27

    Recently, several discriminative learning approaches have been proposed for effective image restoration, achieving convincing trade-off between image quality and computational efficiency. However, these methods require separate training for each restoration task (e.g., denoising, deblurring, demosaicing) and problem condition (e.g., noise level of input images). This makes it time-consuming and difficult to encompass all tasks and conditions during training. In this paper, we propose a discriminative transfer learning method that incorporates formal proximal optimization and discriminative learning for general image restoration. The method requires a single-pass training and allows for reuse across various problems and conditions while achieving an efficiency comparable to previous discriminative approaches. Furthermore, after being trained, our model can be easily transferred to new likelihood terms to solve untrained tasks, or be combined with existing priors to further improve image restoration quality.

  9. Unifying generative and discriminative learning principles

    Directory of Open Access Journals (Sweden)

    Strickert Marc

    2010-02-01

    Full Text Available Abstract Background The recognition of functional binding sites in genomic DNA remains one of the fundamental challenges of genome research. During the last decades, a plethora of different and well-adapted models has been developed, but only little attention has been payed to the development of different and similarly well-adapted learning principles. Only recently it was noticed that discriminative learning principles can be superior over generative ones in diverse bioinformatics applications, too. Results Here, we propose a generalization of generative and discriminative learning principles containing the maximum likelihood, maximum a posteriori, maximum conditional likelihood, maximum supervised posterior, generative-discriminative trade-off, and penalized generative-discriminative trade-off learning principles as special cases, and we illustrate its efficacy for the recognition of vertebrate transcription factor binding sites. Conclusions We find that the proposed learning principle helps to improve the recognition of transcription factor binding sites, enabling better computational approaches for extracting as much information as possible from valuable wet-lab data. We make all implementations available in the open-source library Jstacs so that this learning principle can be easily applied to other classification problems in the field of genome and epigenome analysis.

  10. Neural correlates of face gender discrimination learning.

    Science.gov (United States)

    Su, Junzhu; Tan, Qingleng; Fang, Fang

    2013-04-01

    Using combined psychophysics and event-related potentials (ERPs), we investigated the effect of perceptual learning on face gender discrimination and probe the neural correlates of the learning effect. Human subjects were trained to perform a gender discrimination task with male or female faces. Before and after training, they were tested with the trained faces and other faces with the same and opposite genders. ERPs responding to these faces were recorded. Psychophysical results showed that training significantly improved subjects' discrimination performance and the improvement was specific to the trained gender, as well as to the trained identities. The training effect indicates that learning occurs at two levels-the category level (gender) and the exemplar level (identity). ERP analyses showed that the gender and identity learning was associated with the N170 latency reduction at the left occipital-temporal area and the N170 amplitude reduction at the right occipital-temporal area, respectively. These findings provide evidence for the facilitation model and the sharpening model on neuronal plasticity from visual experience, suggesting a faster processing speed and a sparser representation of face induced by perceptual learning.

  11. Imbalanced Learning Based on Logistic Discrimination.

    Science.gov (United States)

    Guo, Huaping; Zhi, Weimei; Liu, Hongbing; Xu, Mingliang

    2016-01-01

    In recent years, imbalanced learning problem has attracted more and more attentions from both academia and industry, and the problem is concerned with the performance of learning algorithms in the presence of data with severe class distribution skews. In this paper, we apply the well-known statistical model logistic discrimination to this problem and propose a novel method to improve its performance. To fully consider the class imbalance, we design a new cost function which takes into account the accuracies of both positive class and negative class as well as the precision of positive class. Unlike traditional logistic discrimination, the proposed method learns its parameters by maximizing the proposed cost function. Experimental results show that, compared with other state-of-the-art methods, the proposed one shows significantly better performance on measures of recall, g-mean, f-measure, AUC, and accuracy.

  12. Imbalanced Learning Based on Logistic Discrimination

    Directory of Open Access Journals (Sweden)

    Huaping Guo

    2016-01-01

    Full Text Available In recent years, imbalanced learning problem has attracted more and more attentions from both academia and industry, and the problem is concerned with the performance of learning algorithms in the presence of data with severe class distribution skews. In this paper, we apply the well-known statistical model logistic discrimination to this problem and propose a novel method to improve its performance. To fully consider the class imbalance, we design a new cost function which takes into account the accuracies of both positive class and negative class as well as the precision of positive class. Unlike traditional logistic discrimination, the proposed method learns its parameters by maximizing the proposed cost function. Experimental results show that, compared with other state-of-the-art methods, the proposed one shows significantly better performance on measures of recall, g-mean, f-measure, AUC, and accuracy.

  13. Hyperspectral Image Classification Using Discriminative Dictionary Learning

    Science.gov (United States)

    Zongze, Y.; Hao, S.; Kefeng, J.; Huanxin, Z.

    2014-03-01

    The hyperspectral image (HSI) processing community has witnessed a surge of papers focusing on the utilization of sparse prior for effective HSI classification. In sparse representation based HSI classification, there are two phases: sparse coding with an over-complete dictionary and classification. In this paper, we first apply a novel fisher discriminative dictionary learning method, which capture the relative difference in different classes. The competitive selection strategy ensures that atoms in the resulting over-complete dictionary are the most discriminative. Secondly, motivated by the assumption that spatially adjacent samples are statistically related and even belong to the same materials (same class), we propose a majority voting scheme incorporating contextual information to predict the category label. Experiment results show that the proposed method can effectively strengthen relative discrimination of the constructed dictionary, and incorporating with the majority voting scheme achieve generally an improved prediction performance.

  14. Hyperspectral Image Classification Using Discriminative Dictionary Learning

    International Nuclear Information System (INIS)

    Zongze, Y; Hao, S; Kefeng, J; Huanxin, Z

    2014-01-01

    The hyperspectral image (HSI) processing community has witnessed a surge of papers focusing on the utilization of sparse prior for effective HSI classification. In sparse representation based HSI classification, there are two phases: sparse coding with an over-complete dictionary and classification. In this paper, we first apply a novel fisher discriminative dictionary learning method, which capture the relative difference in different classes. The competitive selection strategy ensures that atoms in the resulting over-complete dictionary are the most discriminative. Secondly, motivated by the assumption that spatially adjacent samples are statistically related and even belong to the same materials (same class), we propose a majority voting scheme incorporating contextual information to predict the category label. Experiment results show that the proposed method can effectively strengthen relative discrimination of the constructed dictionary, and incorporating with the majority voting scheme achieve generally an improved prediction performance

  15. Active Discriminative Dictionary Learning for Weather Recognition

    Directory of Open Access Journals (Sweden)

    Caixia Zheng

    2016-01-01

    Full Text Available Weather recognition based on outdoor images is a brand-new and challenging subject, which is widely required in many fields. This paper presents a novel framework for recognizing different weather conditions. Compared with other algorithms, the proposed method possesses the following advantages. Firstly, our method extracts both visual appearance features of the sky region and physical characteristics features of the nonsky region in images. Thus, the extracted features are more comprehensive than some of the existing methods in which only the features of sky region are considered. Secondly, unlike other methods which used the traditional classifiers (e.g., SVM and K-NN, we use discriminative dictionary learning as the classification model for weather, which could address the limitations of previous works. Moreover, the active learning procedure is introduced into dictionary learning to avoid requiring a large number of labeled samples to train the classification model for achieving good performance of weather recognition. Experiments and comparisons are performed on two datasets to verify the effectiveness of the proposed method.

  16. MR PROSTATE SEGMENTATION VIA DISTRIBUTED DISCRIMINATIVE DICTIONARY (DDD) LEARNING.

    Science.gov (United States)

    Guo, Yanrong; Zhan, Yiqiang; Gao, Yaozong; Jiang, Jianguo; Shen, Dinggang

    2013-01-01

    Segmenting prostate from MR images is important yet challenging. Due to non-Gaussian distribution of prostate appearances in MR images, the popular active appearance model (AAM) has its limited performance. Although the newly developed sparse dictionary learning method[1, 2] can model the image appearance in a non-parametric fashion, the learned dictionaries still lack the discriminative power between prostate and non-prostate tissues, which is critical for accurate prostate segmentation. In this paper, we propose to integrate deformable model with a novel learning scheme, namely the Distributed Discriminative Dictionary ( DDD ) learning, which can capture image appearance in a non-parametric and discriminative fashion. In particular, three strategies are designed to boost the tissue discriminative power of DDD. First , minimum Redundancy Maximum Relevance (mRMR) feature selection is performed to constrain the dictionary learning in a discriminative feature space. Second , linear discriminant analysis (LDA) is employed to assemble residuals from different dictionaries for optimal separation between prostate and non-prostate tissues. Third , instead of learning the global dictionaries, we learn a set of local dictionaries for the local regions (each with small appearance variations) along prostate boundary, thus achieving better tissue differentiation locally. In the application stage, DDDs will provide the appearance cues to robustly drive the deformable model onto the prostate boundary. Experiments on 50 MR prostate images show that our method can yield a Dice Ratio of 88% compared to the manual segmentations, and have 7% improvement over the conventional AAM.

  17. Visual Discrimination Learning in the Jumping Spider Phidippus regius

    OpenAIRE

    Massimo De Agrò; Lucia Regolin; Enzo Moretto

    2017-01-01

    Over the past decade, research in comparative psychology has increasingly focused on non-vertebrate models of cognition. Jumping spiders provide excellent models for the study of visually mediated behaviors, such as associative learning or the navigation of complex environments. Here, we tested visual and memory abilities of Phidippus regius to discriminate between artificial geometrical stimuli and to generalize the learned discrimination to illusory stimuli, using the amodal completion mech...

  18. Polarimetric SAR image classification based on discriminative dictionary learning model

    Science.gov (United States)

    Sang, Cheng Wei; Sun, Hong

    2018-03-01

    Polarimetric SAR (PolSAR) image classification is one of the important applications of PolSAR remote sensing. It is a difficult high-dimension nonlinear mapping problem, the sparse representations based on learning overcomplete dictionary have shown great potential to solve such problem. The overcomplete dictionary plays an important role in PolSAR image classification, however for PolSAR image complex scenes, features shared by different classes will weaken the discrimination of learned dictionary, so as to degrade classification performance. In this paper, we propose a novel overcomplete dictionary learning model to enhance the discrimination of dictionary. The learned overcomplete dictionary by the proposed model is more discriminative and very suitable for PolSAR classification.

  19. Horse breed discrimination using machine learning methods

    Czech Academy of Sciences Publication Activity Database

    Burócziová, Monika; Riha, J.

    2009-01-01

    Roč. 50, č. 4 (2009), s. 375-377 ISSN 1234-1983 Institutional research plan: CEZ:AV0Z50450515 Keywords : Breed discrimination * Genetics diversity * Horse breeds Subject RIV: EG - Zoology Impact factor: 1.324, year: 2009

  20. Neighbors Based Discriminative Feature Difference Learning for Kinship Verification

    DEFF Research Database (Denmark)

    Duan, Xiaodong; Tan, Zheng-Hua

    2015-01-01

    In this paper, we present a discriminative feature difference learning method for facial image based kinship verification. To transform feature difference of an image pair to be discriminative for kinship verification, a linear transformation matrix for feature difference between an image pair...... databases show that the proposed method combined with a SVM classification method outperforms or is comparable to state-of-the-art kinship verification methods. © Springer International Publishing AG, Part of Springer Science+Business Media...

  1. Sex differences in discrimination reversal learning in the guppy.

    Science.gov (United States)

    Miletto Petrazzini, Maria Elena; Bisazza, Angelo; Agrillo, Christian; Lucon-Xiccato, Tyrone

    2017-11-01

    In several mammalian and avian species, females show a higher performance than males in tasks requiring cognitive flexibility such as the discrimination reversal learning. A recent study showed that female guppies are twice as efficient as males in a reversal learning task involving yellow-red discrimination, suggesting a higher cognitive flexibility in female guppies. However, the possibility exists that the superior performance exhibited by females does not reflect a general sex difference in cognitive abilities, but instead, is confined to colour discrimination tasks. To address this issue, we compared male and female guppies in two different discrimination reversal learning tasks and we performed a meta-analysis of these experiments and the previous one involving colour discrimination. In the first experiment of this study, guppies were tested in a task requiring them to learn to select the correct arm of a T-maze in order to rejoin a group of conspecifics. In experiment 2, guppies were observed in a numerical task requiring them to discriminate between 5 and 10 dots in order to obtain a food reward. Although females outperformed males in one condition of the T-maze, we did not find any clear evidence of females' greater reversal learning performance in either experiment. However, the meta-analysis of the three experiments supported the hypothesis of females' greater reversal learning ability. Our data do not completely exclude the idea that female guppies have a generally higher cognitive flexibility than males; however, they suggest that the size of this sex difference might depend on the task.

  2. Learned pattern recognition using synthetic-discriminant-functions

    Science.gov (United States)

    Jared, David A.; Ennis, David J.

    1986-01-01

    A method of using synthetic-discriminant-functions to facilitate learning in a pattern recognition system is discussed. Learning is accomplished by continually adding images to the training set used for synthetic discriminant functions (SDF) construction. Object identification is performed by efficiently searching a library of SDF filters for the maximum optical correlation. Two library structures are discussed - binary tree and multilinked graph - along with maximum ascent, back-tracking, perturbation, and simulated annealing searching techniques. By incorporating the distortion invariant properties of SDFs within a library structure, a robust pattern recognition system can be produced.

  3. Learning for pitch and melody discrimination in congenital amusia.

    Science.gov (United States)

    Whiteford, Kelly L; Oxenham, Andrew J

    2018-03-23

    Congenital amusia is currently thought to be a life-long neurogenetic disorder in music perception, impervious to training in pitch or melody discrimination. This study provides an explicit test of whether amusic deficits can be reduced with training. Twenty amusics and 20 matched controls participated in four sessions of psychophysical training involving either pure-tone (500 Hz) pitch discrimination or a control task of lateralization (interaural level differences for bandpass white noise). Pure-tone pitch discrimination at low, medium, and high frequencies (500, 2000, and 8000 Hz) was measured before and after training (pretest and posttest) to determine the specificity of learning. Melody discrimination was also assessed before and after training using the full Montreal Battery of Evaluation of Amusia, the most widely used standardized test to diagnose amusia. Amusics performed more poorly than controls in pitch but not localization discrimination, but both groups improved with practice on the trained stimuli. Learning was broad, occurring across all three frequencies and melody discrimination for all groups, including those who trained on the non-pitch control task. Following training, 11 of 20 amusics no longer met the global diagnostic criteria for amusia. A separate group of untrained controls (n = 20), who also completed melody discrimination and pretest, improved by an equal amount as trained controls on all measures, suggesting that the bulk of learning for the control group occurred very rapidly from the pretest. Thirty-one trained participants (13 amusics) returned one year later to assess long-term maintenance of pitch and melody discrimination. On average, there was no change in performance between posttest and one-year follow-up, demonstrating that improvements on pitch- and melody-related tasks in amusics and controls can be maintained. The findings indicate that amusia is not always a life-long deficit when using the current standard

  4. Visual Discrimination Learning in the Jumping Spider Phidippus regius

    Directory of Open Access Journals (Sweden)

    Massimo De Agrò

    2017-11-01

    Full Text Available Over the past decade, research in comparative psychology has increasingly focused on non-vertebrate models of cognition. Jumping spiders provide excellent models for the study of visually mediated behaviors, such as associative learning or the navigation of complex environments. Here, we tested visual and memory abilities of Phidippus regius to discriminate between artificial geometrical stimuli and to generalize the learned discrimination to illusory stimuli, using the amodal completion mechanism. Spiders were first trained to associate one shape (‘X’ or ‘O’ with a reward (sugar water, whilst the other shape was associated with an aversive taste (acidic water. Spiders were then asked to choose between the two shapes in the absence of any reward or punishment. They were then presented with an occluded version of the previously rewarded shape to test for the presence of amodal completion. Spiders were able to learn the discrimination task, although the association was not transferred to the illusory stimulus. This study provides the first demonstration of shape discrimination learning in a jumping spider. The results of the test on the illusory shape are discussed considering that either the spiders' visual system may not require amodal completion or they could have the tendency to learn the shape associated with the aversive taste rather than that associated with the reward.

  5. Discriminative object tracking via sparse representation and online dictionary learning.

    Science.gov (United States)

    Xie, Yuan; Zhang, Wensheng; Li, Cuihua; Lin, Shuyang; Qu, Yanyun; Zhang, Yinghua

    2014-04-01

    We propose a robust tracking algorithm based on local sparse coding with discriminative dictionary learning and new keypoint matching schema. This algorithm consists of two parts: the local sparse coding with online updated discriminative dictionary for tracking (SOD part), and the keypoint matching refinement for enhancing the tracking performance (KP part). In the SOD part, the local image patches of the target object and background are represented by their sparse codes using an over-complete discriminative dictionary. Such discriminative dictionary, which encodes the information of both the foreground and the background, may provide more discriminative power. Furthermore, in order to adapt the dictionary to the variation of the foreground and background during the tracking, an online learning method is employed to update the dictionary. The KP part utilizes refined keypoint matching schema to improve the performance of the SOD. With the help of sparse representation and online updated discriminative dictionary, the KP part are more robust than the traditional method to reject the incorrect matches and eliminate the outliers. The proposed method is embedded into a Bayesian inference framework for visual tracking. Experimental results on several challenging video sequences demonstrate the effectiveness and robustness of our approach.

  6. Discriminant learning through multiple principal angles for visual recognition.

    Science.gov (United States)

    Su, Ya; Fu, Yun; Gao, Xinbo; Tian, Qi

    2012-03-01

    Canonical correlation has been prevalent for multiset-based pairwise subspace analysis. As an extension, discriminant canonical correlations (DCCs) have been developed for classification purpose by learning a global subspace based on Fisher discriminant modeling of pairwise subspaces. However, the discriminative power of DCCs is not optimal as it only measures the "local" canonical correlations within subspace pairs, which lacks the "global" measurement among all the subspaces. In this paper, we propose a multiset discriminant canonical correlation method, i.e., multiple principal angle (MPA). It jointly considers both "local" and "global" canonical correlations by iteratively learning multiple subspaces (one for each set) as well as a global discriminative subspace, on which the angle among multiple subspaces of the same class is minimized while that of different classes is maximized. The proposed computational solution is guaranteed to be convergent with much faster converging speed than DCC. Extensive experiments on pattern recognition applications demonstrate the superior performance of MPA compared to existing subspace learning methods.

  7. Discriminatively learning for representing local image features with quadruplet model

    Science.gov (United States)

    Zhang, Da-long; Zhao, Lei; Xu, Duan-qing; Lu, Dong-ming

    2017-11-01

    Traditional hand-crafted features for representing local image patches are evolving into current data-driven and learning-based image feature, but learning a robust and discriminative descriptor which is capable of controlling various patch-level computer vision tasks is still an open problem. In this work, we propose a novel deep convolutional neural network (CNN) to learn local feature descriptors. We utilize the quadruplets with positive and negative training samples, together with a constraint to restrict the intra-class variance, to learn good discriminative CNN representations. Compared with previous works, our model reduces the overlap in feature space between corresponding and non-corresponding patch pairs, and mitigates margin varying problem caused by commonly used triplet loss. We demonstrate that our method achieves better embedding result than some latest works, like PN-Net and TN-TG, on benchmark dataset.

  8. Learning discriminative functional network features of schizophrenia

    Science.gov (United States)

    Gheiratmand, Mina; Rish, Irina; Cecchi, Guillermo; Brown, Matthew; Greiner, Russell; Bashivan, Pouya; Polosecki, Pablo; Dursun, Serdar

    2017-03-01

    Associating schizophrenia with disrupted functional connectivity is a central idea in schizophrenia research. However, identifying neuroimaging-based features that can serve as reliable "statistical biomarkers" of the disease remains a challenging open problem. We argue that generalization accuracy and stability of candidate features ("biomarkers") must be used as additional criteria on top of standard significance tests in order to discover more robust biomarkers. Generalization accuracy refers to the utility of biomarkers for making predictions about individuals, for example discriminating between patients and controls, in novel datasets. Feature stability refers to the reproducibility of the candidate features across different datasets. Here, we extracted functional connectivity network features from fMRI data at both high-resolution (voxel-level) and a spatially down-sampled lower-resolution ("supervoxel" level). At the supervoxel level, we used whole-brain network links, while at the voxel level, due to the intractably large number of features, we sampled a subset of them. We compared statistical significance, stability and discriminative utility of both feature types in a multi-site fMRI dataset, composed of schizophrenia patients and healthy controls. For both feature types, a considerable fraction of features showed significant differences between the two groups. Also, both feature types were similarly stable across multiple data subsets. However, the whole-brain supervoxel functional connectivity features showed a higher cross-validation classification accuracy of 78.7% vs. 72.4% for the voxel-level features. Cross-site variability and heterogeneity in the patient samples in the multi-site FBIRN dataset made the task more challenging compared to single-site studies. The use of the above methodology in combination with the fully data-driven approach using the whole brain information have the potential to shed light on "biomarker discovery" in schizophrenia.

  9. Weighted Discriminative Dictionary Learning based on Low-rank Representation

    International Nuclear Information System (INIS)

    Chang, Heyou; Zheng, Hao

    2017-01-01

    Low-rank representation has been widely used in the field of pattern classification, especially when both training and testing images are corrupted with large noise. Dictionary plays an important role in low-rank representation. With respect to the semantic dictionary, the optimal representation matrix should be block-diagonal. However, traditional low-rank representation based dictionary learning methods cannot effectively exploit the discriminative information between data and dictionary. To address this problem, this paper proposed weighted discriminative dictionary learning based on low-rank representation, where a weighted representation regularization term is constructed. The regularization associates label information of both training samples and dictionary atoms, and encourages to generate a discriminative representation with class-wise block-diagonal structure, which can further improve the classification performance where both training and testing images are corrupted with large noise. Experimental results demonstrate advantages of the proposed method over the state-of-the-art methods. (paper)

  10. Can theories of animal discrimination explain perceptual learning in humans?

    Science.gov (United States)

    Mitchell, Chris; Hall, Geoffrey

    2014-01-01

    We present a review of recent studies of perceptual learning conducted with nonhuman animals. The focus of this research has been to elucidate the mechanisms by which mere exposure to a pair of similar stimuli can increase the ease with which those stimuli are discriminated. These studies establish an important role for 2 mechanisms, one involving inhibitory associations between the unique features of the stimuli, the other involving a long-term habituation process that enhances the relative salience of these features. We then examine recent work investigating equivalent perceptual learning procedures with human participants. Our aim is to determine the extent to which the phenomena exhibited by people are susceptible to explanation in terms of the mechanisms revealed by the animal studies. Although we find no evidence that associative inhibition contributes to the perceptual learning effect in humans, initial detection of unique features (those that allow discrimination between 2 similar stimuli) appears to depend on an habituation process. Once the unique features have been detected, a tendency to attend to those features and to learn about their properties enhances subsequent discrimination. We conclude that the effects obtained with humans engage mechanisms additional to those seen in animals but argue that, for the most part, these have their basis in learning processes that are common to animals and people. In a final section, we discuss some implications of this analysis of perceptual learning for other aspects of experimental psychology and consider some potential applications. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

  11. Learning Multi-Instance Deep Discriminative Patterns for Image Classification.

    Science.gov (United States)

    Tang, Peng; Wang, Xinggang; Feng, Bin; Liu, Wenyu

    2017-07-01

    Finding an effective and efficient representation is very important for image classification. The most common approach is to extract a set of local descriptors, and then aggregate them into a high-dimensional, more semantic feature vector, like unsupervised bag-of-features and weakly supervised part-based models. The latter one is usually more discriminative than the former due to the use of information from image labels. In this paper, we propose a weakly supervised strategy that using multi-instance learning (MIL) to learn discriminative patterns for image representation. Specially, we extend traditional multi-instance methods to explicitly learn more than one patterns in positive class, and find the "most positive" instance for each pattern. Furthermore, as the positiveness of instance is treated as a continuous variable, we can use stochastic gradient decent to maximize the margin between different patterns meanwhile considering MIL constraints. To make the learned patterns more discriminative, local descriptors extracted by deep convolutional neural networks are chosen instead of hand-crafted descriptors. Some experimental results are reported on several widely used benchmarks (Action 40, Caltech 101, Scene 15, MIT-indoor, SUN 397), showing that our method can achieve very remarkable performance.

  12. Fornix transection selectively impairs fast learning of conditional visuospatial discriminations.

    Science.gov (United States)

    Kwok, Sze Chai; Buckley, Mark J

    2010-03-01

    As the fornix has previously been implicated in the rapid learning of associations, we hypothesized that fornix transection in macaques would selectively impair the acquisition of rapidly learned conditional visuospatial discrimination problems. Macaque monkeys learned, postoperatively, three sets of concurrent problems of increasing sizes containing 8, 32, and 64 problems, respectively. Each problem consisted of four identical visual stimuli and animals had to learn which stimulus position was rewarded. The lesioned animals made significantly more errors-to-criterion on the smallest set of problems, consistent with the idea that the most rapidly acquired sets would be more vulnerable to fornical damage. Moreover, during the early stages of acquisition across all three sets, fornix transection selectively impeded monkeys' abilities to eliminate nonperseverative errors in correction trials, consistent with an inability to monitor or correct erroneous spatial responses made further back in time than the last trial. Both one-trial learning and an errorless learning (facilitation of performance) were observed in control and fornix lesioned animals but neither were fornix-dependent and overcoming the deleterious effect upon subsequent learning of having made prior errors was also unaffected by fornix transection. The data indicate that the fornix is not important for all forms of new learning; rather it is selectively concerned with the relatively rapid acquisition of spatial and temporal relationships between stimuli and responses.

  13. Sleep enhances inhibitory behavioral control in discrimination learning in rats.

    Science.gov (United States)

    Borquez, Margarita; Born, Jan; Navarro, Victor; Betancourt, Ronald; Inostroza, Marion

    2014-05-01

    Sleep supports the consolidation of memory, and it has been proposed that this enhancing effect of sleep pertains in particular to memories which are encoded under control of prefrontal-hippocampal circuitry into an episodic memory system. Furthermore, repeated reactivation and transformation of such memories during sleep are thought to promote the de-contextualization of these memories. Here, we aimed to establish a behavioral model for the study of such sleep-dependent system consolidation in rats, using a go/nogo conditional discrimination learning task known to essentially depend on prefrontal-hippocampal function. Different groups of rats were trained to criterion on this task and, then, subjected to 80-min retention intervals filled with spontaneous morning sleep, sleep deprivation, or spontaneous evening wakefulness. In a subsequent test phase, the speed of relearning of the discrimination task was examined as indicator of memory, whereby rats were either tested in the same context as during training or in a different context. Sleep promoted relearning of the conditional discrimination task, and this effect was similar for testing memory in the same or different context (p sleep and wakefulness during the retention interval, animals showed faster relearning when tested in the same context as during learning, compared with testing in a different context (p sleep on discrimination learning was primarily due to an enhancing effect on response suppression during the nogo stimulus. We infer from these results that sleep enhances memory for inhibitory behavioral control in a generalized context-independent manner and thereby might eventually also contribute to the abstraction of schema-like representations.

  14. Semi-supervised learning for ordinal Kernel Discriminant Analysis.

    Science.gov (United States)

    Pérez-Ortiz, M; Gutiérrez, P A; Carbonero-Ruz, M; Hervás-Martínez, C

    2016-12-01

    Ordinal classification considers those classification problems where the labels of the variable to predict follow a given order. Naturally, labelled data is scarce or difficult to obtain in this type of problems because, in many cases, ordinal labels are given by a user or expert (e.g. in recommendation systems). Firstly, this paper develops a new strategy for ordinal classification where both labelled and unlabelled data are used in the model construction step (a scheme which is referred to as semi-supervised learning). More specifically, the ordinal version of kernel discriminant learning is extended for this setting considering the neighbourhood information of unlabelled data, which is proposed to be computed in the feature space induced by the kernel function. Secondly, a new method for semi-supervised kernel learning is devised in the context of ordinal classification, which is combined with our developed classification strategy to optimise the kernel parameters. The experiments conducted compare 6 different approaches for semi-supervised learning in the context of ordinal classification in a battery of 30 datasets, showing (1) the good synergy of the ordinal version of discriminant analysis and the use of unlabelled data and (2) the advantage of computing distances in the feature space induced by the kernel function. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Discriminative Unsupervised Feature Learning with Exemplar Convolutional Neural Networks.

    Science.gov (United States)

    Dosovitskiy, Alexey; Fischer, Philipp; Springenberg, Jost Tobias; Riedmiller, Martin; Brox, Thomas

    2016-09-01

    Deep convolutional networks have proven to be very successful in learning task specific features that allow for unprecedented performance on various computer vision tasks. Training of such networks follows mostly the supervised learning paradigm, where sufficiently many input-output pairs are required for training. Acquisition of large training sets is one of the key challenges, when approaching a new task. In this paper, we aim for generic feature learning and present an approach for training a convolutional network using only unlabeled data. To this end, we train the network to discriminate between a set of surrogate classes. Each surrogate class is formed by applying a variety of transformations to a randomly sampled 'seed' image patch. In contrast to supervised network training, the resulting feature representation is not class specific. It rather provides robustness to the transformations that have been applied during training. This generic feature representation allows for classification results that outperform the state of the art for unsupervised learning on several popular datasets (STL-10, CIFAR-10, Caltech-101, Caltech-256). While features learned with our approach cannot compete with class specific features from supervised training on a classification task, we show that they are advantageous on geometric matching problems, where they also outperform the SIFT descriptor.

  16. Global discriminative learning for higher-accuracy computational gene prediction.

    Directory of Open Access Journals (Sweden)

    Axel Bernal

    2007-03-01

    Full Text Available Most ab initio gene predictors use a probabilistic sequence model, typically a hidden Markov model, to combine separately trained models of genomic signals and content. By combining separate models of relevant genomic features, such gene predictors can exploit small training sets and incomplete annotations, and can be trained fairly efficiently. However, that type of piecewise training does not optimize prediction accuracy and has difficulty in accounting for statistical dependencies among different parts of the gene model. With genomic information being created at an ever-increasing rate, it is worth investigating alternative approaches in which many different types of genomic evidence, with complex statistical dependencies, can be integrated by discriminative learning to maximize annotation accuracy. Among discriminative learning methods, large-margin classifiers have become prominent because of the success of support vector machines (SVM in many classification tasks. We describe CRAIG, a new program for ab initio gene prediction based on a conditional random field model with semi-Markov structure that is trained with an online large-margin algorithm related to multiclass SVMs. Our experiments on benchmark vertebrate datasets and on regions from the ENCODE project show significant improvements in prediction accuracy over published gene predictors that use intrinsic features only, particularly at the gene level and on genes with long introns.

  17. Histopathological Image Classification using Discriminative Feature-oriented Dictionary Learning

    Science.gov (United States)

    Vu, Tiep Huu; Mousavi, Hojjat Seyed; Monga, Vishal; Rao, Ganesh; Rao, UK Arvind

    2016-01-01

    In histopathological image analysis, feature extraction for classification is a challenging task due to the diversity of histology features suitable for each problem as well as presence of rich geometrical structures. In this paper, we propose an automatic feature discovery framework via learning class-specific dictionaries and present a low-complexity method for classification and disease grading in histopathology. Essentially, our Discriminative Feature-oriented Dictionary Learning (DFDL) method learns class-specific dictionaries such that under a sparsity constraint, the learned dictionaries allow representing a new image sample parsimoniously via the dictionary corresponding to the class identity of the sample. At the same time, the dictionary is designed to be poorly capable of representing samples from other classes. Experiments on three challenging real-world image databases: 1) histopathological images of intraductal breast lesions, 2) mammalian kidney, lung and spleen images provided by the Animal Diagnostics Lab (ADL) at Pennsylvania State University, and 3) brain tumor images from The Cancer Genome Atlas (TCGA) database, reveal the merits of our proposal over state-of-the-art alternatives. Moreover, we demonstrate that DFDL exhibits a more graceful decay in classification accuracy against the number of training images which is highly desirable in practice where generous training is often not available. PMID:26513781

  18. Hierarchical discriminant manifold learning for dimensionality reduction and image classification

    Science.gov (United States)

    Chen, Weihai; Zhao, Changchen; Ding, Kai; Wu, Xingming; Chen, Peter C. Y.

    2015-09-01

    In the field of image classification, it has been a trend that in order to deliver a reliable classification performance, the feature extraction model becomes increasingly more complicated, leading to a high dimensionality of image representations. This, in turn, demands greater computation resources for image classification. Thus, it is desirable to apply dimensionality reduction (DR) methods for image classification. It is necessary to apply DR methods to relieve the computational burden as well as to improve the classification accuracy. However, traditional DR methods are not compatible with modern feature extraction methods. A framework that combines manifold learning based DR and feature extraction in a deeper way for image classification is proposed. A multiscale cell representation is extracted from the spatial pyramid to satisfy the locality constraints for a manifold learning method. A spectral weighted mean filtering is proposed to eliminate noise in the feature space. A hierarchical discriminant manifold learning is proposed which incorporates both category label and image scale information to guide the DR process. Finally, the image representation is generated by concatenating dimensionality reduced cell representations from the same image. Extensive experiments are conducted to test the proposed algorithm on both scene and object recognition datasets in comparison with several well-established and state-of-the-art methods with respect to classification precision and computational time. The results verify the effectiveness of incorporating manifold learning in the feature extraction procedure and imply that the multiscale cell representations may be distributed on a manifold.

  19. Auditory neurophysiologic responses and discrimination deficits in children with learning problems.

    Science.gov (United States)

    Kraus, N; McGee, T J; Carrell, T D; Zecker, S G; Nicol, T G; Koch, D B

    1996-08-16

    Children with learning problems often cannot discriminate rapid acoustic changes that occur in speech. In this study of normal children and children with learning problems, impaired behavioral discrimination of a rapid speech change (/dalpha/versus/galpha/) was correlated with diminished magnitude of an electrophysiologic measure that is not dependent on attention or a voluntary response. The ability of children with learning problems to discriminate another rapid speech change (/balpha/versus/walpha/) also was reflected in the neurophysiology. These results indicate that some children's discrimination deficits originate in the auditory pathway before conscious perception and have implications for differential diagnosis and targeted therapeutic strategies for children with learning disabilities and attention disorders.

  20. Effects of Learning about Gender Discrimination on Adolescent Girls' Attitudes toward and Interest in Science

    Science.gov (United States)

    Weisgram, Erica S.; Bigler, Rebecca S.

    2007-01-01

    Gender discrimination has contributed to the gender imbalance in scientific fields. However, research on the effects of informing adolescent girls about gender discrimination in these fields is rare and controversial. To examine the consequences of learning about gender-based occupational discrimination, adolescent girls (n= 158, ages 11 to 14)…

  1. Effects of Learning about Historical Gender Discrimination on Early Adolescents' Occupational Judgments and Aspirations

    Science.gov (United States)

    Pahlke, Erin; Bigler, Rebecca S.; Green, Vanessa A.

    2010-01-01

    To examine the consequences of learning about gender discrimination, early adolescents (n = 121, aged 10-14) were randomly assigned to receive either (a) standard biographical lessons about historical figures (standard condition) or (b) nearly identical lessons that included information about gender discrimination (discrimination condition).…

  2. Discriminative Block-Diagonal Representation Learning for Image Recognition.

    Science.gov (United States)

    Zhang, Zheng; Xu, Yong; Shao, Ling; Yang, Jian

    2017-07-04

    Existing block-diagonal representation studies mainly focuses on casting block-diagonal regularization on training data, while only little attention is dedicated to concurrently learning both block-diagonal representations of training and test data. In this paper, we propose a discriminative block-diagonal low-rank representation (BDLRR) method for recognition. In particular, the elaborate BDLRR is formulated as a joint optimization problem of shrinking the unfavorable representation from off-block-diagonal elements and strengthening the compact block-diagonal representation under the semisupervised framework of LRR. To this end, we first impose penalty constraints on the negative representation to eliminate the correlation between different classes such that the incoherence criterion of the extra-class representation is boosted. Moreover, a constructed subspace model is developed to enhance the self-expressive power of training samples and further build the representation bridge between the training and test samples, such that the coherence of the learned intraclass representation is consistently heightened. Finally, the resulting optimization problem is solved elegantly by employing an alternative optimization strategy, and a simple recognition algorithm on the learned representation is utilized for final prediction. Extensive experimental results demonstrate that the proposed method achieves superb recognition results on four face image data sets, three character data sets, and the 15 scene multicategories data set. It not only shows superior potential on image recognition but also outperforms the state-of-the-art methods.

  3. Fronto-striatal grey matter contributions to discrimination learning in Parkinson's disease

    NARCIS (Netherlands)

    O'Callaghan, C.; Moustafa, A.A.; de Wit, S.; Shine, J.M.; Robbins, T.W.; Lewis, S.J.G.; Hornberger, M.

    2013-01-01

    Discrimination learning deficits in Parkinson's disease (PD) have been well-established. Using both behavioral patient studies and computational approaches, these deficits have typically been attributed to dopamine imbalance across the basal ganglia. However, this explanation of impaired learning in

  4. Impaired Discrimination Learning in Mice Lacking the NMDA Receptor NR2A Subunit

    Science.gov (United States)

    Brigman, Jonathan L.; Feyder, Michael; Saksida, Lisa M.; Bussey, Timothy J.; Mishina, Masayoshi; Holmes, Andrew

    2008-01-01

    N-Methyl-D-aspartate receptors (NMDARs) mediate certain forms of synaptic plasticity and learning. We used a touchscreen system to assess NR2A subunit knockout mice (KO) for (1) pairwise visual discrimination and reversal learning and (2) acquisition and extinction of an instrumental response requiring no pairwise discrimination. NR2A KO mice…

  5. Discriminative dictionary learning for abdominal multi-organ segmentation.

    Science.gov (United States)

    Tong, Tong; Wolz, Robin; Wang, Zehan; Gao, Qinquan; Misawa, Kazunari; Fujiwara, Michitaka; Mori, Kensaku; Hajnal, Joseph V; Rueckert, Daniel

    2015-07-01

    An automated segmentation method is presented for multi-organ segmentation in abdominal CT images. Dictionary learning and sparse coding techniques are used in the proposed method to generate target specific priors for segmentation. The method simultaneously learns dictionaries which have reconstructive power and classifiers which have discriminative ability from a set of selected atlases. Based on the learnt dictionaries and classifiers, probabilistic atlases are then generated to provide priors for the segmentation of unseen target images. The final segmentation is obtained by applying a post-processing step based on a graph-cuts method. In addition, this paper proposes a voxel-wise local atlas selection strategy to deal with high inter-subject variation in abdominal CT images. The segmentation performance of the proposed method with different atlas selection strategies are also compared. Our proposed method has been evaluated on a database of 150 abdominal CT images and achieves a promising segmentation performance with Dice overlap values of 94.9%, 93.6%, 71.1%, and 92.5% for liver, kidneys, pancreas, and spleen, respectively. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  6. Perceptual Learning: 12-Month-Olds' Discrimination of Monkey Faces

    Science.gov (United States)

    Fair, Joseph; Flom, Ross; Jones, Jacob; Martin, Justin

    2012-01-01

    Six-month-olds reliably discriminate different monkey and human faces whereas 9-month-olds only discriminate different human faces. It is often falsely assumed that perceptual narrowing reflects a permanent change in perceptual abilities. In 3 experiments, ninety-six 12-month-olds' discrimination of unfamiliar monkey faces was examined. Following…

  7. Auditory Discrimination as a Condition for E-Learning Based Speech Therapy: A Proposal for an Auditory Discrimination Test (ADT) for Adult Dysarthric Speakers

    Science.gov (United States)

    Beijer, L. J.; Rietveld, A. C. M.; van Stiphout, A. J. L.

    2011-01-01

    Background: Web based speech training for dysarthric speakers, such as E-learning based Speech Therapy (EST), puts considerable demands on auditory discrimination abilities. Aims: To discuss the development and the evaluation of an auditory discrimination test (ADT) for the assessment of auditory speech discrimination skills in Dutch adult…

  8. Teaching for Equity, Learning about Discrimination in a Meritocratic Society

    Science.gov (United States)

    Cruz, Fátima; Stake, Robert E.

    2012-01-01

    In this paper, we will examine key points for research attention in the effort to commit educational systems to equity education. We will examine the concepts of equity, equality and discrimination. We will give specific attention to the role of teacher educators. Teachers need to understand and to be able to see social discrimination in…

  9. Post-training depletions of basolateral amygdala serotonin fail to disrupt discrimination, retention, or reversal learning

    Directory of Open Access Journals (Sweden)

    G. Jesus eOchoa

    2015-05-01

    Full Text Available In goal-directed pursuits, the basolateral amygdala (BLA is critical in learning about changes in the value of rewards. BLA-lesioned rats show enhanced reversal learning, a task employed to measure the flexibility of response to changes in reward. Similarly, there is a trend for enhanced discrimination learning, suggesting that BLA may modulate formation of stimulus-reward associations. There is a parallel literature on the importance of serotonin (5HT in new stimulus-reward and reversal learning. Recent postulations implicate 5HT in learning from punishment. Whereas dopaminergic involvement is critical in behavioral activation and reinforcement, 5HT may be most critical for aversive processing and behavioral inhibition, complementary cognitive processes. Given these findings, a 5HT-mediated mechanism in BLA may mediate the facilitated learning observed previously. The present study investigated the effects of selective 5HT lesions in BLA using 5,7-dihydroxytryptamine (5,7-DHT versus infusions of saline (Sham on discrimination, retention, and deterministic reversal learning. Rats were required to reach an 85% correct pairwise discrimination and single reversal criterion prior to surgery. Postoperatively, rats were then tested on the 1 retention of the pretreatment discrimination pair 2 discrimination of a novel pair and 3 reversal learning performance. We found statistically comparable preoperative learning rates between groups, intact postoperative retention, and unaltered novel discrimination and reversal learning in 5,7-DHT rats. These findings suggest that 5HT in BLA is not required for formation and flexible adjustment of new stimulus-reward associations when the strategy to efficiently solve the task has already been learned. Given the complementary role of orbitofrontal cortex in reward learning and its interconnectivity with BLA, these findings add to the list of dissociable mechanisms for BLA and orbitofrontal cortex in reward learning.

  10. Combining generative and discriminative representation learning for lung CT analysis with convolutional restricted Boltzmann machines

    DEFF Research Database (Denmark)

    van Tulder, Gijs; de Bruijne, Marleen

    2016-01-01

    outperform these standard filter banks because they learn a feature description directly from the training data. Like many other representation learning methods, restricted Boltzmann machines are unsupervised and are trained with a generative learning objective; this allows them to learn representations from...... for describing the training data and for classification. We present experiments with feature learning for lung texture classification and airway detection in CT images. In both applications, a combination of learning objectives outperformed purely discriminative or generative learning, increasing, for instance......, the lung tissue classification accuracy by 1 to 8 percentage points. This shows that discriminative learning can help an otherwise unsupervised feature learner to learn filters that are optimized for classification....

  11. Interaction between age and perceptual similarity in olfactory discrimination learning in F344 rats: relationships with spatial learning

    Science.gov (United States)

    Yoder, Wendy M.; Gaynor, Leslie S.; Burke, Sara N.; Setlow, Barry; Smith, David W.; Bizon, Jennifer L.

    2017-01-01

    Emerging evidence suggests that aging is associated with a reduced ability to distinguish perceptually similar stimuli in one’s environment. As the ability to accurately perceive and encode sensory information is foundational for explicit memory, understanding the neurobiological underpinnings of discrimination impairments that emerge with advancing age could help elucidate the mechanisms of mnemonic decline. To this end, there is a need for preclinical approaches that robustly and reliably model age-associated perceptual discrimination deficits. Taking advantage of rodents’ exceptional olfactory abilities, the present study applied rigorous psychophysical techniques to the evaluation of discrimination learning in young and aged F344 rats. Aging did not influence odor detection thresholds or the ability to discriminate between perceptually distinct odorants. In contrast, aged rats were disproportionately impaired relative to young on problems that required discriminations between perceptually similar olfactory stimuli. Importantly, these disproportionate impairments in discrimination learning did not simply reflect a global learning impairment in aged rats, as they performed other types of difficult discriminations on par with young rats. Among aged rats, discrimination deficits were strongly associated with spatial learning deficits. These findings reveal a new, sensitive behavioral approach for elucidating the neural mechanisms of cognitive decline associated with normal aging. PMID:28259065

  12. Learning linear discriminant projections for dimensionality reduction of image descriptors.

    Science.gov (United States)

    Cai, Hongping; Mikolajczyk, Krystian; Matas, Jiri

    2011-02-01

    In this paper, we present Linear Discriminant Projections (LDP) for reducing dimensionality and improving discriminability of local image descriptors. We place LDP into the context of state-of-the-art discriminant projections and analyze its properties. LDP requires a large set of training data with point-to-point correspondence ground truth. We demonstrate that training data produced by a simulation of image transformations leads to nearly the same results as the real data with correspondence ground truth. This makes it possible to apply LDP as well as other discriminant projection approaches to the problems where the correspondence ground truth is not available, such as image categorization. We perform an extensive experimental evaluation on standard data sets in the context of image matching and categorization. We demonstrate that LDP enables significant dimensionality reduction of local descriptors and performance increases in different applications. The results improve upon the state-of-the-art recognition performance with simultaneous dimensionality reduction from 128 to 30.

  13. Reduced autobiographical memory specificity is associated with impaired discrimination learning in anxiety disorder patients

    Science.gov (United States)

    Lenaert, Bert; Boddez, Yannick; Vervliet, Bram; Schruers, Koen; Hermans, Dirk

    2015-01-01

    Associative learning plays an important role in the development of anxiety disorders, but a thorough understanding of the variables that impact such learning is still lacking. We investigated whether individual differences in autobiographical memory specificity are related to discrimination learning and generalization. In an associative learning task, participants learned the association between two pictures of female faces and a non-aversive outcome. Subsequently, six morphed pictures functioning as generalization stimuli (GSs) were introduced. In a sample of healthy participants (Study 1), we did not find evidence for differences in discrimination learning as a function of memory specificity. In a sample of anxiety disorder patients (Study 2), individuals who were characterized by low memory specificity showed deficient discrimination learning relative to high specific individuals. In contrast to previous findings, results revealed no effect of memory specificity on generalization. These results indicate that impaired discrimination learning, previously shown in patients suffering from an anxiety disorder, may be—in part—due to limited memory specificity. Together, these studies emphasize the importance of incorporating cognitive variables in associative learning theories and their implications for the development of anxiety disorders. In addition, re-analyses of the data (Study 3) showed that patients suffering from panic disorder showed higher outcome expectancies in the presence of the stimulus that was never followed by an outcome during discrimination training, relative to patients suffering from other anxiety disorders and healthy participants. Because we used a neutral, non-aversive outcome (i.e., drawing of a lightning bolt), these data suggest that learning abnormalities in panic disorder may not be restricted to fear learning, but rather reflect a more general associative learning deficit that also manifests in fear irrelevant contexts. PMID

  14. Reduced autobiographical memory specificity is associated with impaired discrimination learning in anxiety disorder patients

    Directory of Open Access Journals (Sweden)

    Bert eLenaert

    2015-07-01

    Full Text Available Associative learning plays an important role in the development of anxiety disorders, but a thorough understanding of the variables that impact such learning is still lacking. We investigated whether individual differences in autobiographical memory specificity are related to discrimination learning and generalization. In an associative learning task, participants learned the association between two pictures of female faces and a non-aversive outcome. Subsequently, six morphed pictures functioning as generalization stimuli (GSs were introduced. In a sample of healthy participants (Study 1, we did not find evidence for differences in discrimination learning as a function of memory specificity. In a sample of anxiety disorder patients (Study 2, individuals who were characterized by low memory specificity showed deficient discrimination learning relative to high specific individuals. In contrast to previous findings, results revealed no effect of memory specificity on generalization. These results indicate that impaired discrimination learning, previously shown in patients suffering from an anxiety disorder, may be – in part – due to limited memory specificity. Together, these studies emphasize the importance of incorporating cognitive variables in associative learning theories and their implications for the development of anxiety disorders. In addition, re-analyses of the data (Study 3 showed that patients suffering from panic disorder showed higher outcome expectancies in the presence of the stimulus that was never followed by an outcome during discrimination training, relative to patients suffering from other anxiety disorders and healthy participants. Because we used a neutral, non-aversive outcome (i.e., drawing of a lightning bolt, these data suggest that learning abnormalities in panic disorder may not be restricted to fear learning, but rather reflect a more general associative learning deficit that also manifests in fear irrelevant

  15. Corpus linguistics and naive discriminative learning A linguística de corpus e a aprendizagem discriminativa ingênua

    OpenAIRE

    R. Harald Baayen

    2011-01-01

    Three classifiers from machine learning (the generalized linear mixed model, memory based learning, and support vector machines) are compared with a naive discriminative learning classifier, derived from basic principles of error-driven learning characterizing animal and human learning. Tested on the dative alternation in English, using the Switchboard data from (BRESNAN; CUENI; NIKITINA; BAAYEN, 2007), naive discriminative learning emerges with stateof-the-art predictive accuracy. Naive disc...

  16. Discriminating Microbial Species Using Protein Sequence Properties and Machine Learning

    NARCIS (Netherlands)

    Shahib, Ali Al-; Gilbert, David; Breitling, Rainer

    2007-01-01

    Much work has been done to identify species-specific proteins in sequenced genomes and hence to determine their function. We assumed that such proteins have specific physico-chemical properties that will discriminate them from proteins in other species. In this paper, we examine the validity of this

  17. Task discrimination from myoelectric activity: a learning scheme for EMG-based interfaces.

    Science.gov (United States)

    Liarokapis, Minas V; Artemiadis, Panagiotis K; Kyriakopoulos, Kostas J

    2013-06-01

    A learning scheme based on Random Forests is used to discriminate the task to be executed using only myoelectric activity from the upper limb. Three different task features can be discriminated: subspace to move towards, object to be grasped and task to be executed (with the object). The discrimination between the different reach to grasp movements is accomplished with a random forests classifier, which is able to perform efficient features selection, helping us to reduce the number of EMG channels required for task discrimination. The proposed scheme can take advantage of both a classifier and a regressor that cooperate advantageously to split the task space, providing better estimation accuracy with task-specific EMG-based motion decoding models, as reported in [1] and [2]. The whole learning scheme can be used by a series of EMG-based interfaces, that can be found in rehabilitation cases and neural prostheses.

  18. Flexible Configural Learning of Non-Linear Discriminations and Detection of Stimulus Compounds.

    Science.gov (United States)

    Glautier, Steven; Menneer, Tamaryn; Godwin, Hayward J; Donnelly, Nick; Aristizabal, José A

    2016-07-01

    Previous work showed that prior experience with discriminations requiring configural solutions (e.g., biconditional discrimination) confers an advantage for the learning of new configural discriminations (e.g., negative patterning) in comparison to prior experience with elemental discriminations. This effect is well established but its mechanism is not well understood. In the studies described below we assessed whether the saliences of configural and element cues were affected by prior training. We observed positive transfer to a new configural discrimination after configural pre-training but we were unable to find evidence for changes in cue salience using a signal-detection task. Our results confirm previous work by demonstrating experience-dependent flexibility in cue processing but they also suggest that this flexibility occurs at a point in the stimulus processing pipeline later than 1-2 s after the presentation of stimulus inputs. (138 words).

  19. Automated visual choice discrimination learning in zebrafish (Danio rerio).

    Science.gov (United States)

    Mueller, Kaspar P; Neuhauss, Stephan C F

    2012-03-01

    Training experimental animals to discriminate between different visual stimuli has been an important tool in cognitive neuroscience as well as in vision research for many decades. Current methods used for visual choice discrimination training of zebrafish require human observers for response tracking, stimulus presentation and reward delivery and, consequently, are very labor intensive and possibly experimenter biased. By combining video tracking of fish positions, stimulus presentation on computer monitors and food delivery by computer-controlled electromagnetic valves, we developed a method that allows for a fully automated training of multiple adult zebrafish to arbitrary visual stimuli in parallel. The standardized training procedure facilitates the comparison of results across different experiments and laboratories and contributes to the usability of zebrafish as vertebrate model organisms in behavioral brain research and vision research.

  20. Longitudinal changes in auditory discrimination in normal children and children with language-learning problems.

    Science.gov (United States)

    Elliott, L L; Hammer, M A

    1988-11-01

    Two groups of children--one progressing normally in school and the other exhibiting language-learning problems--were tested in each of 3 years on a set of fine-grained auditory discrimination tasks that required listening for small acoustic differences. Children's ages ranged from 6 to 9 years; there were 21 children per group. The children with language-learning problems, despite having normal intelligence and normal pure-tone sensitivity, showed poorer auditory discrimination than normal children for temporally based acoustic differences. This effect continued across the 3 years. Children with language-learning problems also exhibited poorer receptive vocabulary and language performance as well as more deviations from standard Midwest articulation than children making normal progress in school. All children had hearing within the normal range, but at some frequencies there was a significant association of pure-tone sensitivity with performance on the auditory discrimination, receptive language, and speech production tasks.

  1. Transfer in motion discrimination learning was no greater in double training than in single training.

    Science.gov (United States)

    Huang, Jinfeng; Liang, Ju; Zhou, Yifeng; Liu, Zili

    2017-06-01

    We investigated the controversy regarding double training in motion discrimination learning. We collected data from 43 participants in a motion direction discrimination learning task with either double training (i.e., training plus exposure) or single training (i.e., no exposure). By pooling these data with those in the literature, we had data in double training from 28 participants and in single training from 36 participants. We found that, in double training, the transfer along the exposed direction was less than that along the trained direction, indicating incomplete transfer. Importantly, the transfer in double training was not reliably greater than that in single training.

  2. Dopamine modulates memory consolidation of discrimination learning in the auditory cortex.

    Science.gov (United States)

    Schicknick, Horst; Reichenbach, Nicole; Smalla, Karl-Heinz; Scheich, Henning; Gundelfinger, Eckart D; Tischmeyer, Wolfgang

    2012-03-01

    In Mongolian gerbils, the auditory cortex is critical for discriminating rising vs. falling frequency-modulated tones. Based on our previous studies, we hypothesized that dopaminergic inputs to the auditory cortex during and shortly after acquisition of the discrimination strategy control long-term memory formation. To test this hypothesis, we studied frequency-modulated tone discrimination learning of gerbils in a shuttle box GO/NO-GO procedure following differential treatments. (i) Pre-exposure of gerbils to the frequency-modulated tones at 1 day before the first discrimination training session severely impaired the accuracy of the discrimination acquired in that session during the initial trials of a second training session, performed 1 day later. (ii) Local injection of the D1/D5 dopamine receptor antagonist SCH-23390 into the auditory cortex after task acquisition caused a discrimination deficit of similar extent and time course as with pre-exposure. This effect was dependent on the dose and time point of injection. (iii) Injection of the D1/D5 dopamine receptor agonist SKF-38393 into the auditory cortex after retraining caused a further discrimination improvement at the beginning of subsequent sessions. All three treatments, which supposedly interfered with dopamine signalling during conditioning and/or retraining, had a substantial impact on the dynamics of the discrimination performance particularly at the beginning of subsequent training sessions. These findings suggest that auditory-cortical dopamine activity after acquisition of a discrimination of complex sounds and after retrieval of weak frequency-modulated tone discrimination memory further improves memory consolidation, i.e. the correct association of two sounds with their respective GO/NO-GO meaning, in support of future memory recall. © 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  3. Valence of Facial Cues Influences Sheep Learning in a Visual Discrimination Task

    Directory of Open Access Journals (Sweden)

    Lucille G. A. Bellegarde

    2017-11-01

    Full Text Available Sheep are one of the most studied farm species in terms of their ability to process information from faces, but little is known about their face-based emotion recognition abilities. We investigated (a whether sheep could use images of sheep faces taken in situation of varying valence as cues in a simultaneous discrimination task and (b whether the valence of the situation affects their learning performance. To accomplish this, we photographed faces of sheep in three situations inducing emotional states of neutral (ruminating in the home pen or negative valence (social isolation or aggressive interaction. Sheep (n = 35 first had to learn a discrimination task with colored cards. Animals that reached the learning criterion (n = 16 were then presented with pairs of images of the face of a single individual taken in the neutral situation and in one of the negative situations. Finally, sheep had to generalize what they had learned to new pairs of images of faces taken in the same situation, but of a different conspecific. All sheep that learned the discrimination task with colored cards reached the learning criterion with images of faces. Sheep that had to associate a negative image with a food reward learned faster than sheep that had to associate a neutral image with a reward. With the exception of sheep from the aggression-rewarded group, sheep generalized this discrimination to images of faces of different individuals. Our results suggest that sheep can perceive the emotional valence displayed on faces of conspecifics and that this valence affects learning processes.

  4. Robust Visual Tracking via Online Discriminative and Low-Rank Dictionary Learning.

    Science.gov (United States)

    Zhou, Tao; Liu, Fanghui; Bhaskar, Harish; Yang, Jie

    2017-09-12

    In this paper, we propose a novel and robust tracking framework based on online discriminative and low-rank dictionary learning. The primary aim of this paper is to obtain compact and low-rank dictionaries that can provide good discriminative representations of both target and background. We accomplish this by exploiting the recovery ability of low-rank matrices. That is if we assume that the data from the same class are linearly correlated, then the corresponding basis vectors learned from the training set of each class shall render the dictionary to become approximately low-rank. The proposed dictionary learning technique incorporates a reconstruction error that improves the reliability of classification. Also, a multiconstraint objective function is designed to enable active learning of a discriminative and robust dictionary. Further, an optimal solution is obtained by iteratively computing the dictionary, coefficients, and by simultaneously learning the classifier parameters. Finally, a simple yet effective likelihood function is implemented to estimate the optimal state of the target during tracking. Moreover, to make the dictionary adaptive to the variations of the target and background during tracking, an online update criterion is employed while learning the new dictionary. Experimental results on a publicly available benchmark dataset have demonstrated that the proposed tracking algorithm performs better than other state-of-the-art trackers.

  5. Multi-level discriminative dictionary learning with application to large scale image classification.

    Science.gov (United States)

    Shen, Li; Sun, Gang; Huang, Qingming; Wang, Shuhui; Lin, Zhouchen; Wu, Enhua

    2015-10-01

    The sparse coding technique has shown flexibility and capability in image representation and analysis. It is a powerful tool in many visual applications. Some recent work has shown that incorporating the properties of task (such as discrimination for classification task) into dictionary learning is effective for improving the accuracy. However, the traditional supervised dictionary learning methods suffer from high computation complexity when dealing with large number of categories, making them less satisfactory in large scale applications. In this paper, we propose a novel multi-level discriminative dictionary learning method and apply it to large scale image classification. Our method takes advantage of hierarchical category correlation to encode multi-level discriminative information. Each internal node of the category hierarchy is associated with a discriminative dictionary and a classification model. The dictionaries at different layers are learnt to capture the information of different scales. Moreover, each node at lower layers also inherits the dictionary of its parent, so that the categories at lower layers can be described with multi-scale information. The learning of dictionaries and associated classification models is jointly conducted by minimizing an overall tree loss. The experimental results on challenging data sets demonstrate that our approach achieves excellent accuracy and competitive computation cost compared with other sparse coding methods for large scale image classification.

  6. Discrimination of Breast Cancer with Microcalcifications on Mammography by Deep Learning.

    Science.gov (United States)

    Wang, Jinhua; Yang, Xi; Cai, Hongmin; Tan, Wanchang; Jin, Cangzheng; Li, Li

    2016-06-07

    Microcalcification is an effective indicator of early breast cancer. To improve the diagnostic accuracy of microcalcifications, this study evaluates the performance of deep learning-based models on large datasets for its discrimination. A semi-automated segmentation method was used to characterize all microcalcifications. A discrimination classifier model was constructed to assess the accuracies of microcalcifications and breast masses, either in isolation or combination, for classifying breast lesions. Performances were compared to benchmark models. Our deep learning model achieved a discriminative accuracy of 87.3% if microcalcifications were characterized alone, compared to 85.8% with a support vector machine. The accuracies were 61.3% for both methods with masses alone and improved to 89.7% and 85.8% after the combined analysis with microcalcifications. Image segmentation with our deep learning model yielded 15, 26 and 41 features for the three scenarios, respectively. Overall, deep learning based on large datasets was superior to standard methods for the discrimination of microcalcifications. Accuracy was increased by adopting a combinatorial approach to detect microcalcifications and masses simultaneously. This may have clinical value for early detection and treatment of breast cancer.

  7. A stimulus-location effect in contingency-governed, but not rule-based, discrimination learning.

    Science.gov (United States)

    Meier, Christina; Lea, Stephen E G; McLaren, Ian P L

    2016-04-01

    We tested pigeons' acquisition of a conditional discrimination task between colored grating stimuli that included choosing 1 of 2 response keys, which either appeared as white keys to the left and right of the discriminative stimulus, or were replicas of the stimulus. Pigeons failed to acquire the discrimination when the response keys were white disks but succeeded when directly responding to a replica of the stimulus. These results highlight how conditioning processes shape learning in pigeons: The results can be accounted for by supposing that, when pigeons were allowed to respond directly toward the stimulus, learning was guided by classical conditioning, but that responding to white keys demanded instrumental learning, which impaired task acquisition for pigeons. In contrast, humans completing the same paradigm showed no differential learning success depending on whether figure or position indicated the correct key. However, only participants who could state the underlying discrimination rule acquired the task, which implies that human performance in this situation relied on the deduction and application of task rules instead of associative processes. (c) 2016 APA, all rights reserved).

  8. Automatic face naming by learning discriminative affinity matrices from weakly labeled images.

    Science.gov (United States)

    Xiao, Shijie; Xu, Dong; Wu, Jianxin

    2015-10-01

    Given a collection of images, where each image contains several faces and is associated with a few names in the corresponding caption, the goal of face naming is to infer the correct name for each face. In this paper, we propose two new methods to effectively solve this problem by learning two discriminative affinity matrices from these weakly labeled images. We first propose a new method called regularized low-rank representation by effectively utilizing weakly supervised information to learn a low-rank reconstruction coefficient matrix while exploring multiple subspace structures of the data. Specifically, by introducing a specially designed regularizer to the low-rank representation method, we penalize the corresponding reconstruction coefficients related to the situations where a face is reconstructed by using face images from other subjects or by using itself. With the inferred reconstruction coefficient matrix, a discriminative affinity matrix can be obtained. Moreover, we also develop a new distance metric learning method called ambiguously supervised structural metric learning by using weakly supervised information to seek a discriminative distance metric. Hence, another discriminative affinity matrix can be obtained using the similarity matrix (i.e., the kernel matrix) based on the Mahalanobis distances of the data. Observing that these two affinity matrices contain complementary information, we further combine them to obtain a fused affinity matrix, based on which we develop a new iterative scheme to infer the name of each face. Comprehensive experiments demonstrate the effectiveness of our approach.

  9. Multi-Site Diagnostic Classification of Schizophrenia Using Discriminant Deep Learning with Functional Connectivity MRI.

    Science.gov (United States)

    Zeng, Ling-Li; Wang, Huaning; Hu, Panpan; Yang, Bo; Pu, Weidan; Shen, Hui; Chen, Xingui; Liu, Zhening; Yin, Hong; Tan, Qingrong; Wang, Kai; Hu, Dewen

    2018-03-23

    A lack of a sufficiently large sample at single sites causes poor generalizability in automatic diagnosis classification of heterogeneous psychiatric disorders such as schizophrenia based on brain imaging scans. Advanced deep learning methods may be capable of learning subtle hidden patterns from high dimensional imaging data, overcome potential site-related variation, and achieve reproducible cross-site classification. However, deep learning-based cross-site transfer classification, despite less imaging site-specificity and more generalizability of diagnostic models, has not been investigated in schizophrenia. A large multi-site functional MRI sample (n = 734, including 357 schizophrenic patients from seven imaging resources) was collected, and a deep discriminant autoencoder network, aimed at learning imaging site-shared functional connectivity features, was developed to discriminate schizophrenic individuals from healthy controls. Accuracies of approximately 85·0% and 81·0% were obtained in multi-site pooling classification and leave-site-out transfer classification, respectively. The learned functional connectivity features revealed dysregulation of the cortical-striatal-cerebellar circuit in schizophrenia, and the most discriminating functional connections were primarily located within and across the default, salience, and control networks. The findings imply that dysfunctional integration of the cortical-striatal-cerebellar circuit across the default, salience, and control networks may play an important role in the "disconnectivity" model underlying the pathophysiology of schizophrenia. The proposed discriminant deep learning method may be capable of learning reliable connectome patterns and help in understanding the pathophysiology and achieving accurate prediction of schizophrenia across multiple independent imaging sites. Copyright © 2018. Published by Elsevier B.V.

  10. A perceptual learning deficit in Chinese developmental dyslexia as revealed by visual texture discrimination training.

    Science.gov (United States)

    Wang, Zhengke; Cheng-Lai, Alice; Song, Yan; Cutting, Laurie; Jiang, Yuzheng; Lin, Ou; Meng, Xiangzhi; Zhou, Xiaolin

    2014-08-01

    Learning to read involves discriminating between different written forms and establishing connections with phonology and semantics. This process may be partially built upon visual perceptual learning, during which the ability to process the attributes of visual stimuli progressively improves with practice. The present study investigated to what extent Chinese children with developmental dyslexia have deficits in perceptual learning by using a texture discrimination task, in which participants were asked to discriminate the orientation of target bars. Experiment l demonstrated that, when all of the participants started with the same initial stimulus-to-mask onset asynchrony (SOA) at 300 ms, the threshold SOA, adjusted according to response accuracy for reaching 80% accuracy, did not show a decrement over 5 days of training for children with dyslexia, whereas this threshold SOA steadily decreased over the training for the control group. Experiment 2 used an adaptive procedure to determine the threshold SOA for each participant during training. Results showed that both the group of dyslexia and the control group attained perceptual learning over the sessions in 5 days, although the threshold SOAs were significantly higher for the group of dyslexia than for the control group; moreover, over individual participants, the threshold SOA negatively correlated with their performance in Chinese character recognition. These findings suggest that deficits in visual perceptual processing and learning might, in part, underpin difficulty in reading Chinese. Copyright © 2014 John Wiley & Sons, Ltd.

  11. Noise-robust unsupervised spike sorting based on discriminative subspace learning with outlier handling

    Science.gov (United States)

    Keshtkaran, Mohammad Reza; Yang, Zhi

    2017-06-01

    Objective. Spike sorting is a fundamental preprocessing step for many neuroscience studies which rely on the analysis of spike trains. Most of the feature extraction and dimensionality reduction techniques that have been used for spike sorting give a projection subspace which is not necessarily the most discriminative one. Therefore, the clusters which appear inherently separable in some discriminative subspace may overlap if projected using conventional feature extraction approaches leading to a poor sorting accuracy especially when the noise level is high. In this paper, we propose a noise-robust and unsupervised spike sorting algorithm based on learning discriminative spike features for clustering. Approach. The proposed algorithm uses discriminative subspace learning to extract low dimensional and most discriminative features from the spike waveforms and perform clustering with automatic detection of the number of the clusters. The core part of the algorithm involves iterative subspace selection using linear discriminant analysis and clustering using Gaussian mixture model with outlier detection. A statistical test in the discriminative subspace is proposed to automatically detect the number of the clusters. Main results. Comparative results on publicly available simulated and real in vivo datasets demonstrate that our algorithm achieves substantially improved cluster distinction leading to higher sorting accuracy and more reliable detection of clusters which are highly overlapping and not detectable using conventional feature extraction techniques such as principal component analysis or wavelets. Significance. By providing more accurate information about the activity of more number of individual neurons with high robustness to neural noise and outliers, the proposed unsupervised spike sorting algorithm facilitates more detailed and accurate analysis of single- and multi-unit activities in neuroscience and brain machine interface studies.

  12. Aversive reinforcement improves visual discrimination learning in free-flying honeybees.

    Directory of Open Access Journals (Sweden)

    Aurore Avarguès-Weber

    Full Text Available BACKGROUND: Learning and perception of visual stimuli by free-flying honeybees has been shown to vary dramatically depending on the way insects are trained. Fine color discrimination is achieved when both a target and a distractor are present during training (differential conditioning, whilst if the same target is learnt in isolation (absolute conditioning, discrimination is coarse and limited to perceptually dissimilar alternatives. Another way to potentially enhance discrimination is to increase the penalty associated with the distractor. Here we studied whether coupling the distractor with a highly concentrated quinine solution improves color discrimination of both similar and dissimilar colors by free-flying honeybees. As we assumed that quinine acts as an aversive stimulus, we analyzed whether aversion, if any, is based on an aversive sensory input at the gustatory level or on a post-ingestional malaise following quinine feeding. METHODOLOGY/PRINCIPAL FINDINGS: We show that the presence of a highly concentrated quinine solution (60 mM acts as an aversive reinforcer promoting rejection of the target associated with it, and improving discrimination of perceptually similar stimuli but not of dissimilar stimuli. Free-flying bees did not use remote cues to detect the presence of quinine solution; the aversive effect exerted by this substance was mediated via a gustatory input, i.e. via a distasteful sensory experience, rather than via a post-ingestional malaise. CONCLUSION: The present study supports the hypothesis that aversion conditioning is important for understanding how and what animals perceive and learn. By using this form of conditioning coupled with appetitive conditioning in the framework of a differential conditioning procedure, it is possible to uncover discrimination capabilities that may remain otherwise unsuspected. We show, therefore, that visual discrimination is not an absolute phenomenon but can be modulated by experience.

  13. Observations on auditory learning in amplitude- and frequency-modulation rate discrimination

    DEFF Research Database (Denmark)

    Hoffmann, Pablo F.

    2010-01-01

    . One of the key issues when designing such training systems is in the assessment of transfer of learning. In this study we present data on the learning of an auditory task involving sinusoidal amplitude- and frequency-modulated tones. Modulation rate discrimination thresholds were measured during pre...... applications by addressing the transfer of learning across carrier frequency, modulation rate, and modulation type.......Because amplitude- and frequency-modulated sounds can be the basis for the synthesis of many complex sounds, they can be good candidates in the design of training systems aiming at improving the acquisition of perceptual skills that can benefit from information provided via the auditory channel...

  14. The role of visual cortex acetylcholine in learning to discriminate temporally modulated visual stimuli

    Directory of Open Access Journals (Sweden)

    Victor H Minces

    2013-03-01

    Full Text Available Cholinergic neurons in the basal forebrain innervate discrete regions of the cortical mantle, bestowing the cholinergic system with the potential to dynamically modulate sub-regions of the cortex according to behavioral demands. Cortical cholinergic activity has been shown to facilitate learning and modulate attention. Experiments addressing these issues have primarily focused on widespread cholinergic depletions, extending to areas involved in general cognitive processes and sleep cycle regulation, making a definitive interpretation of the behavioral role of cholinergic projections difficult. Furthermore, a review of the electrophysiological literature suggests that cholinergic modulation is particularly important in representing the fine temporal details of stimuli, an issue rarely addressed in behavioral experimentation. The goal of this work is to understand the role cholinergic projections, specific to the sensory cortex, in learning to discriminate fine differences in the temporal structure of stimuli. A novel visual Go/No-Go task was developed to assess the ability of rats to learn and discriminate fine differences in the temporal structure of visual stimuli (lights flashing at various frequencies. The cholinergic contribution to this task was examined by selectively eliminating acetylcholine projections to visual cortex (using 192 IgG-saporin, either before or after discrimination training.We find that in the face of compromised cholinergic input to the visual cortex, the rats’ ability to learn to perform fine discriminations is impaired, whereas their ability to perform discriminations remains unaffected.These results suggest that acetylcholine serves the role of facilitating plastic changes in the sensory cortices that are needed for an animal to refine their sensitivity to the temporal characteristics of relevant stimuli.

  15. Aging effects on discrimination learning, logical reasoning and memory in pet dogs.

    Science.gov (United States)

    Wallis, Lisa J; Virányi, Zsófia; Müller, Corsin A; Serisier, Samuel; Huber, Ludwig; Range, Friederike

    2016-02-01

    In laboratory dogs, aging leads to a decline in various cognitive domains such as learning, memory and behavioural flexibility. However, much less is known about aging in pet dogs, i.e. dogs that are exposed to different home environments by their caregivers. We used tasks on a touchscreen apparatus to detect differences in various cognitive functions across pet Border Collies aged from 5 months to 13 years. Ninety-five dogs were divided into five age groups and tested in four tasks: (1) underwater photo versus drawing discrimination, (2) clip art picture discrimination, (3) inferential reasoning by exclusion and (4) a memory test with a retention interval of 6 months. The tasks were designed to test three cognitive abilities: visual discrimination learning, logical reasoning and memory. The total number of sessions to reach criterion and the number of correction trials needed in the two discrimination tasks were compared across age groups. The results showed that both measures increased linearly with age, with dogs aged over 13 years displaying slower learning and reduced flexibility in comparison to younger dogs. Inferential reasoning ability increased with age, but less than 10 % of dogs showed patterns of choice consistent with inference by exclusion. No age effect was found in the long-term memory test. In conclusion, the discrimination learning tests used are suitable to detect cognitive aging in pet dogs, which can serve as a basis for comparison to help diagnose cognition-related problems and as a tool to assist with the development of treatments to delay cognitive decline.

  16. Abnormal strategies during visual discrimination reversal learning in ephrin-A2(-/-) mice.

    Science.gov (United States)

    Arnall, S; Cheam, L Y; Smart, C; Rengel, A; Fitzgerald, M; Thivierge, J P; Rodger, J

    2010-05-01

    Eph receptors and ephrins are involved in establishing topographic connectivity in primary sensory brain regions, but also in higher order structures including the cortex and hippocampus. Ephrin-A2(-/-) mice have abnormal topography in the primary visual system but have normal visual and learning performance on a simple visual discrimination task. Here we use signal detection theory to analyse learning behaviour of these mice. Wild-type (WT) and ephrin-A2(-/-) (KO) mice performed equally well in a two-stimulus visual discrimination task, with similar learning rates and response latencies. However, during reversal learning, when the rewarded stimulus was switched, the two genotypes exhibited differences in response strategies: while WTs favoured a win-stay strategy, KOs remained relatively neutral. KOs also exhibited a stronger lateralization bias in the initial stages of learning, choosing the same arm of the maze with high probability. In addition, use of a Bayesian "optimal observer" revealed that compared to WT, KO mice adapted their decisions less rapidly to a change in stimulus-reward relationship. We suggest that the misexpression of ephrin-A2 may lead to abnormal connectivity in regions known for their involvement in reversal learning and perseverative behaviours, including thalamic-prefrontal cortical-striatal circuitry and particularly orbitofrontal cortex. The implication is that topographic organisation of higher order brain regions may play an important role in learning and decision making.

  17. Male and female guppies differ in speed but not in accuracy in visual discrimination learning.

    Science.gov (United States)

    Lucon-Xiccato, Tyrone; Bisazza, Angelo

    2016-07-01

    In many species, males and females have different reproductive roles and/or differ in their ecological niche. Since in these cases the two sexes often face different cognitive challenges, selection may promote some degree of cognitive differentiation, an issue that has received relatively little attention so far. We investigated the existence of sex differences in visual discrimination learning in the guppy, Poecilia reticulata, a fish species in which females show complex mate choice based on male colour pattern. We tested males and females for their ability to learn a discrimination between two different shapes (experiment 1) and between two identical figures with a different orientation (experiment 2). In experiment 3, guppies were required to select an object of the odd colour in a group of five objects. Colours changed daily, and therefore, the solution for this task was facilitated by concept learning. We found males' and females' accuracy practically overlapped in the three experiments, suggesting that the two sexes have similar discrimination learning abilities. Yet, males showed faster decision time than females without any evident speed-accuracy trade-off. This result indicates the existence of consistent between-sex differences in decision speed perhaps due to impulsivity rather than speed in information processing. Our results align with previous literature, indicating that sex differences in cognitive abilities are the exception rather than the rule, while sex differences in cognitive style, i.e. the way in which an individual faces a cognitive task, are much more common.

  18. Vicarious trial-and-error behavior and hippocampal cytochrome oxidase activity during Y-maze discrimination learning in the rat.

    Science.gov (United States)

    Hu, Dan; Xu, Xiaojuan; Gonzalez-Lima, Francisco

    2006-03-01

    The present study investigated whether more vicarious trial-and-error (VTE) behavior, defined by head movement from one stimulus to another at a choice point during simultaneous discriminations, led to better visual discrimination learning in a Y-maze, and whether VTE behavior was a function of the hippocampus by measuring regional brain cytochrome oxidase (C.O.) activity, an index of neuronal metabolic activity. The results showed that the more VTEs a rat made, the better the rat learned the visual discrimination. Furthermore, both learning and VTE behavior during learning were correlated to C.O. activity in the hippocampus, suggesting that the hippocampus plays a role in VTE behavior during discrimination learning.

  19. Unsupervised learning of discriminative edge measures for vehicle matching between nonoverlapping cameras.

    Science.gov (United States)

    Shan, Ying; Sawhney, Harpreet S; Kumar, Rakesh

    2008-04-01

    This paper proposes a novel unsupervised algorithm learning discriminative features in the context of matching road vehicles between two non-overlapping cameras. The matching problem is formulated as a same-different classification problem, which aims to compute the probability of vehicle images from two distinct cameras being from the same vehicle or different vehicle(s). We employ a novel measurement vector that consists of three independent edge-based measures and their associated robust measures computed from a pair of aligned vehicle edge maps. The weight of each measure is determined by an unsupervised learning algorithm that optimally separates the same-different classes in the combined measurement space. This is achieved with a weak classification algorithm that automatically collects representative samples from same-different classes, followed by a more discriminative classifier based on Fisher' s Linear Discriminants and Gibbs Sampling. The robustness of the match measures and the use of unsupervised discriminant analysis in the classification ensures that the proposed method performs consistently in the presence of missing/false features, temporally and spatially changing illumination conditions, and systematic misalignment caused by different camera configurations. Extensive experiments based on real data of over 200 vehicles at different times of day demonstrate promising results.

  20. Fairer machine learning in the real world: Mitigating discrimination without collecting sensitive data

    Directory of Open Access Journals (Sweden)

    Michael Veale

    2017-11-01

    Full Text Available Decisions based on algorithmic, machine learning models can be unfair, reproducing biases in historical data used to train them. While computational techniques are emerging to address aspects of these concerns through communities such as discrimination-aware data mining (DADM and fairness, accountability and transparency machine learning (FATML, their practical implementation faces real-world challenges. For legal, institutional or commercial reasons, organisations might not hold the data on sensitive attributes such as gender, ethnicity, sexuality or disability needed to diagnose and mitigate emergent indirect discrimination-by-proxy, such as redlining. Such organisations might also lack the knowledge and capacity to identify and manage fairness issues that are emergent properties of complex sociotechnical systems. This paper presents and discusses three potential approaches to deal with such knowledge and information deficits in the context of fairer machine learning. Trusted third parties could selectively store data necessary for performing discrimination discovery and incorporating fairness constraints into model-building in a privacy-preserving manner. Collaborative online platforms would allow diverse organisations to record, share and access contextual and experiential knowledge to promote fairness in machine learning systems. Finally, unsupervised learning and pedagogically interpretable algorithms might allow fairness hypotheses to be built for further selective testing and exploration. Real-world fairness challenges in machine learning are not abstract, constrained optimisation problems, but are institutionally and contextually grounded. Computational fairness tools are useful, but must be researched and developed in and with the messy contexts that will shape their deployment, rather than just for imagined situations. Not doing so risks real, near-term algorithmic harm.

  1. Transfer of Perceptual Learning of Depth Discrimination Between Local and Global Stereograms

    OpenAIRE

    Gantz, Liat; Bedell, Harold

    2010-01-01

    Several previous studies reported differences when stereothresholds are assessed with local-contour stereograms vs. complex random-dot stereograms (RDSs). Dissimilar thresholds may be due to differences in the properties of the stereograms (e.g., spatial frequency content, contrast, inter-element separation, area) or to different underlying processing mechanisms. This study examined the transfer of perceptual learning of depth discrimination between local and global RDSs with similar properti...

  2. Discriminative kernel feature extraction and learning for object recognition and detection

    DEFF Research Database (Denmark)

    Pan, Hong; Olsen, Søren Ingvor; Zhu, Yaping

    2015-01-01

    Feature extraction and learning is critical for object recognition and detection. By embedding context cue of image attributes into the kernel descriptors, we propose a set of novel kernel descriptors called context kernel descriptors (CKD). The motivation of CKD is to use the spatial consistency...... codebook and reduced CKD are discriminative. We report superior performance of our algorithm for object recognition on benchmark datasets like Caltech-101 and CIFAR-10, as well as for detection on a challenging chicken feet dataset....... of image attributes or features defined within a neighboring region to improve the robustness of descriptor matching in kernel space. For feature learning, we develop a novel codebook learning method, based on the Cauchy-Schwarz Quadratic Mutual Information (CSQMI) measure, to learn a compact...

  3. Combining MFD and PIE for accurate single-pair Förster resonance energy transfer measurements.

    Science.gov (United States)

    Kudryavtsev, Volodymyr; Sikor, Martin; Kalinin, Stanislav; Mokranjac, Dejana; Seidel, Claus A M; Lamb, Don C

    2012-03-01

    Single-pair Förster resonance energy transfer (spFRET) experiments using single-molecule burst analysis on a confocal microscope are an ideal tool to measure inter- and intramolecular distances and dynamics on the nanoscale. Different techniques have been developed to maximize the amount of information available in spFRET burst analysis experiments. Multiparameter fluorescence detection (MFD) is used to monitor a variety of fluorescence parameters simultaneously and pulsed interleaved excitation (PIE) employs direct excitation of the acceptor to probe its presence and photoactivity. To calculate accurate FRET efficiencies from spFRET experiments with MFD or PIE, several calibration measurements are usually required. Herein, we demonstrate that by combining MFD with PIE information regarding all calibration factors as well as an accurate determination of spFRET histograms can be performed in a single measurement. In addition, the quality of overlap of the different detection volumes as well as the detection of acceptor photophysics can be investigated with MFD-PIE. Bursts containing acceptor photobleaching can be identified and excluded from further investigation while bursts that contain FRET dynamics are unaffected by this analysis. We have employed MFD-PIE to accurately analyze the effects of nucleotides and substrate on the interdomain separation in DnaK, the major bacterial heat shock protein 70 (Hsp70). The interdomain distance increases from 47 Å in the ATP-bound state to 84 Å in the ADP-bound state and slightly contracts to 77 Å when a substrate is bound. This is in contrast to what was observed for the mitochondrial member of the Hsp70s, Ssc1, supporting the notion of evolutionary specialization of Hsp70s for different cellular functions in different organisms and cell organelles. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Perceptual learning and Aging: Improved performance for low contrast motion discrimination

    Directory of Open Access Journals (Sweden)

    Jeffrey eBower

    2013-02-01

    Full Text Available Previous research has shown age related differences in discriminating motion at different levels of contrast (Betts, Sekuler, & Bennett, 2009; 2012; Betts, Taylor, Sekuler & Bennett, 2005. A surprising result of this research is that older as compared to younger observers showed improved performance in detecting motion of large high contrast stimuli suggesting age-related differences in center-surround antagonism. In the present study we examined whether perceptual learning methods could be used to improve motion discrimination performance for older individuals under high- and low-contrast conditions. The stimuli were centrally presented Gaussian filtered sine-wave gratings (Gabors that were either 5 or 0.7 degree diameter with contrast of 0.92, 0.22, or 0.028. Older and younger participants received 3 days of training. The task was to identify if the motion direction was leftward or rightward. Duration thresholds for motion discrimination were derived using two randomly interleaved staircases and compared between pre-/post- test sessions. Both older and younger subjects showed lower duration thresholds as a result of training. The improved performance, for older subjects, due to training was observed for all size and contrast conditions, with training with small low-contrast stimuli resulting in a 23% improvement in motion discrimination performance. Older observers, as compared to younger observers, did show evidence of decreased spatial suppression across all contrast levels. These results suggest that perceptual learning techniques are effective for improving motion discrimination performance, especially for conditions that are difficult for older individuals.

  5. Neural substrate for higher-order learning in an insect: Mushroom bodies are necessary for configural discriminations.

    Science.gov (United States)

    Devaud, Jean-Marc; Papouin, Thomas; Carcaud, Julie; Sandoz, Jean-Christophe; Grünewald, Bernd; Giurfa, Martin

    2015-10-27

    Learning theories distinguish elemental from configural learning based on their different complexity. Although the former relies on simple and unambiguous links between the learned events, the latter deals with ambiguous discriminations in which conjunctive representations of events are learned as being different from their elements. In mammals, configural learning is mediated by brain areas that are either dispensable or partially involved in elemental learning. We studied whether the insect brain follows the same principles and addressed this question in the honey bee, the only insect in which configural learning has been demonstrated. We used a combination of conditioning protocols, disruption of neural activity, and optophysiological recording of olfactory circuits in the bee brain to determine whether mushroom bodies (MBs), brain structures that are essential for memory storage and retrieval, are equally necessary for configural and elemental olfactory learning. We show that bees with anesthetized MBs distinguish odors and learn elemental olfactory discriminations but not configural ones, such as positive and negative patterning. Inhibition of GABAergic signaling in the MB calyces, but not in the lobes, impairs patterning discrimination, thus suggesting a requirement of GABAergic feedback neurons from the lobes to the calyces for nonelemental learning. These results uncover a previously unidentified role for MBs besides memory storage and retrieval: namely, their implication in the acquisition of ambiguous discrimination problems. Thus, in insects as in mammals, specific brain regions are recruited when the ambiguity of learning tasks increases, a fact that reveals similarities in the neural processes underlying the elucidation of ambiguous tasks across species.

  6. Spatial discrimination and visual discrimination

    DEFF Research Database (Denmark)

    Haagensen, Annika M. J.; Grand, Nanna; Klastrup, Signe

    2013-01-01

    in a visual discrimination test. The juvenile minipigs were able to learn the spatial hole-board discrimination test and showed improved working and reference memory during the learning phase. Performance in the memory phases was affected by the retention intervals, but the minipigs were able to remember...... the concept of the test in both memory phases. Working memory and reference memory were significantly improved in the last trials of the memory phases. In the visual discrimination test, the minipigs learned to discriminate between the three figures presented to them within 9-14 sessions. For the memory test......Two methods investigating learning and memory in juvenile Gottingen minipigs were evaluated for potential use in preclinical toxicity testing. Twelve minipigs were tested using a spatial hole-board discrimination test including a learning phase and two memory phases. Five minipigs were tested...

  7. Normative data and discriminant validity of Rey's Verbal Learning Test for the Greek adult population.

    Science.gov (United States)

    Messinis, Lambros; Tsakona, Ioanna; Malefaki, Sonia; Papathanasopoulos, Panagiotis

    2007-08-01

    The present study sought to establish normative and discriminant validity data for Rey's Auditory Verbal Learning Test [Rey, A. (1964). L 'examen clinique en psychologie [Clinical tests in psychology]. Paris: Presses Universitaires de France; Schmidt, M. (1996). Rey auditory verbal learning test: A handbook. Los Angeles, CA: Western Psychological Services] using newly adapted learning lists for the Greek adult population. Applying the procedure suggested by Geffen et al. [Geffen, G., Moar, K. J., O'Hanlon, A. P., Clark, C. R., & Geffen, L. N. (1990). Performance measures of 16-86-year-old males and females on the auditory verbal learning test. The Clinical Neuropsychologist, 4, 45-63] we administered the test to 205 healthy participants, aged 18-78 years and two adult patient groups (long-term cannabis users and HIV symptomatic patients). Stepwise linear regression analyses showed that the variables age, education and gender contributed significantly to most trials of the RAVLT. Performance decreased in an age-dependent manner from young adulthood. Women, young adults and higher educated participants outperformed men, older adults and less educated individuals. The test appears to discriminate adequately between the performance of long-term heavy cannabis users and HIV seropositive symptomatic patients and matched healthy controls, as both patient groups performed more poorly than their respective control group. Normative data stratified by age, gender and education for the Greek adult population is presented for use in research and clinical settings.

  8. Does Fine Color Discrimination Learning in Free-Flying Honeybees Change Mushroom-Body Calyx Neuroarchitecture?

    Science.gov (United States)

    Sommerlandt, Frank M J; Spaethe, Johannes; Rössler, Wolfgang; Dyer, Adrian G

    2016-01-01

    Honeybees learn color information of rewarding flowers and recall these memories in future decisions. For fine color discrimination, bees require differential conditioning with a concurrent presentation of target and distractor stimuli to form a long-term memory. Here we investigated whether the long-term storage of color information shapes the neural network of microglomeruli in the mushroom body calyces and if this depends on the type of conditioning. Free-flying honeybees were individually trained to a pair of perceptually similar colors in either absolute conditioning towards one of the colors or in differential conditioning with both colors. Subsequently, bees of either conditioning groups were tested in non-rewarded discrimination tests with the two colors. Only bees trained with differential conditioning preferred the previously learned color, whereas bees of the absolute conditioning group, and a stimuli-naïve group, chose randomly among color stimuli. All bees were then kept individually for three days in the dark to allow for complete long-term memory formation. Whole-mount immunostaining was subsequently used to quantify variation of microglomeruli number and density in the mushroom-body lip and collar. We found no significant differences among groups in neuropil volumes and total microglomeruli numbers, but learning performance was negatively correlated with microglomeruli density in the absolute conditioning group. Based on these findings we aim to promote future research approaches combining behaviorally relevant color learning tests in honeybees under free-flight conditions with neuroimaging analysis; we also discuss possible limitations of this approach.

  9. Depth-Aware Salient Object Detection and Segmentation via Multiscale Discriminative Saliency Fusion and Bootstrap Learning.

    Science.gov (United States)

    Song, Hangke; Liu, Zhi; Du, Huan; Sun, Guangling; Le Meur, Olivier; Ren, Tongwei

    2017-09-01

    This paper proposes a novel depth-aware salient object detection and segmentation framework via multiscale discriminative saliency fusion (MDSF) and bootstrap learning for RGBD images (RGB color images with corresponding Depth maps) and stereoscopic images. By exploiting low-level feature contrasts, mid-level feature weighted factors and high-level location priors, various saliency measures on four classes of features are calculated based on multiscale region segmentation. A random forest regressor is learned to perform the discriminative saliency fusion (DSF) and generate the DSF saliency map at each scale, and DSF saliency maps across multiple scales are combined to produce the MDSF saliency map. Furthermore, we propose an effective bootstrap learning-based salient object segmentation method, which is bootstrapped with samples based on the MDSF saliency map and learns multiple kernel support vector machines. Experimental results on two large datasets show how various categories of features contribute to the saliency detection performance and demonstrate that the proposed framework achieves the better performance on both saliency detection and salient object segmentation.

  10. Segmentation of MR images via discriminative dictionary learning and sparse coding: application to hippocampus labeling.

    Science.gov (United States)

    Tong, Tong; Wolz, Robin; Coupé, Pierrick; Hajnal, Joseph V; Rueckert, Daniel

    2013-08-01

    We propose a novel method for the automatic segmentation of brain MRI images by using discriminative dictionary learning and sparse coding techniques. In the proposed method, dictionaries and classifiers are learned simultaneously from a set of brain atlases, which can then be used for the reconstruction and segmentation of an unseen target image. The proposed segmentation strategy is based on image reconstruction, which is in contrast to most existing atlas-based labeling approaches that rely on comparing image similarities between atlases and target images. In addition, we propose a Fixed Discriminative Dictionary Learning for Segmentation (F-DDLS) strategy, which can learn dictionaries offline and perform segmentations online, enabling a significant speed-up in the segmentation stage. The proposed method has been evaluated for the hippocampus segmentation of 80 healthy ICBM subjects and 202 ADNI images. The robustness of the proposed method, especially of our F-DDLS strategy, was validated by training and testing on different subject groups in the ADNI database. The influence of different parameters was studied and the performance of the proposed method was also compared with that of the nonlocal patch-based approach. The proposed method achieved a median Dice coefficient of 0.879 on 202 ADNI images and 0.890 on 80 ICBM subjects, which is competitive compared with state-of-the-art methods. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Weakly electric fish learn both visual and electrosensory cues in a multisensory object discrimination task.

    Science.gov (United States)

    Dangelmayer, Sandra; Benda, Jan; Grewe, Jan

    2016-10-01

    Weakly electric fish use electrosensory, visual, olfactory and lateral line information to guide foraging and navigation behaviors. In many cases they preferentially rely on electrosensory cues. Do fish also memorize non-electrosensory cues? Here, we trained individuals of gymnotiform weakly electric fish Apteronotus albifrons in an object discrimination task. Objects were combinations of differently conductive materials covered with differently colored cotton hoods. By setting visual and electrosensory cues in conflict we analyzed the sensory hierarchy among the electrosensory and the visual sense in object discrimination. Our experiments show that: (i) black ghost knifefish can be trained to solve discrimination tasks similarly to the mormyrid fish; (ii) fish preferentially rely on electrosensory cues for object discrimination; (iii) despite the dominance of the electrosense they still learn the visual cue and use it when electrosensory information is not available; (iv) fish prefer the trained combination of rewarded cues over combinations that match only in a single feature and also memorize the non-rewarded combination. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Pigeons learn stimulus identity and stimulus relations when both serve as redundant, relevant cues during same-different discrimination training.

    Science.gov (United States)

    Gibson, Brett M; Wasserman, Edward A

    2003-01-01

    The authors taught pigeons to discriminate displays of 16 identical items from displays of 16 nonidentical items. Unlike most same-different discrimination studies--where only stimulus relations could serve a discriminative function--both the identity of the items and the relations among the items were discriminative features of the displays. The pigeons learned about both stimulus identity and stimulus relations when these 2 sources of information served as redundant, relevant cues. In tests of associative competition, identity cues exerted greater stimulus control than relational cues. These results suggest that the pigeon can respond to both specific stimuli and general relations in the environment.

  13. English- and Mandarin-learning infants' discrimination of actions and objects in dynamic events.

    Science.gov (United States)

    Chen, Jie; Tardif, Twila; Pulverman, Rachel; Casasola, Marianella; Zhu, Liqi; Zheng, Xiaobei; Meng, Xiangzhi

    2015-10-01

    The present studies examined the role of linguistic experience in directing English and Mandarin learners' attention to aspects of a visual scene. Specifically, they asked whether young language learners in these 2 cultures attend to differential aspects of a word-learning situation. Two groups of English and Mandarin learners, 6-8-month-olds (n = 65) and 17-19-month-olds (n = 91), participated in 2 studies, based on a habituation paradigm, designed to test infants' discrimination between actions and objects in dynamic events. In Study 1, these stimuli were presented in silence, whereas in Study 2, a verbal label accompanied videos. Results showed that 6-8-month-olds could discriminate action changes but not object changes, whereas 17-19-month-olds could discriminate both types of changes. However, there were only very subtle cross-linguistic differences in these patterns when the scenes were presented together with a verbal label. These findings show strong evidence for universal developmental trends in attention, with somewhat weaker evidence that the differences in the types of words Mandarin- versus English-learning children produce or are exposed to affect attention to different aspects of a scene in the first 2 years of life. (c) 2015 APA, all rights reserved).

  14. Semi-Supervised Tensor-Based Graph Embedding Learning and Its Application to Visual Discriminant Tracking.

    Science.gov (United States)

    Hu, Weiming; Gao, Jin; Xing, Junliang; Zhang, Chao; Maybank, Stephen

    2017-01-01

    An appearance model adaptable to changes in object appearance is critical in visual object tracking. In this paper, we treat an image patch as a two-order tensor which preserves the original image structure. We design two graphs for characterizing the intrinsic local geometrical structure of the tensor samples of the object and the background. Graph embedding is used to reduce the dimensions of the tensors while preserving the structure of the graphs. Then, a discriminant embedding space is constructed. We prove two propositions for finding the transformation matrices which are used to map the original tensor samples to the tensor-based graph embedding space. In order to encode more discriminant information in the embedding space, we propose a transfer-learning- based semi-supervised strategy to iteratively adjust the embedding space into which discriminative information obtained from earlier times is transferred. We apply the proposed semi-supervised tensor-based graph embedding learning algorithm to visual tracking. The new tracking algorithm captures an object's appearance characteristics during tracking and uses a particle filter to estimate the optimal object state. Experimental results on the CVPR 2013 benchmark dataset demonstrate the effectiveness of the proposed tracking algorithm.

  15. Brightness discrimination learning in a Skinner box in prenatally X-irradiated rats

    International Nuclear Information System (INIS)

    Tamaki, Y.; Inouye, M.

    1976-01-01

    Male MP 1 albino rats were exposed to x-irradiation in utero at a single dose of 200 R on day 17 of gestation. The light-dark discrimination training in a Skinner box was continued until the animals attained a learning criterion of 0.80 correct response ratio for 3 consecutive days. Although during the unreinforced baseline sessions the total number of bar pressings in the irradiated animals was superior to that in the controls, performance between the control and the irradiated animals did not differ significantly in (a) the number of training days required to attain the learning criterion, (b) the total number of days on which the animals produced a correct response ratio more than 0.80, and (c) the number of consecutive days during which the correct response ratio was more than 0.75. The results obtained suggest that the irradiated animals were able to discriminate in brightness cues as well, or nearly as well, as the controls. The cortical-subcortical system mediating brightness discrimination in the irradiated animals is discussed. (author)

  16. Machinery fault diagnosis using joint global and local/nonlocal discriminant analysis with selective ensemble learning

    Science.gov (United States)

    Yu, Jianbo

    2016-11-01

    The vibration signals of faulty machine are generally non-stationary and nonlinear under those complicated working conditions. Thus, it is a big challenge to extract and select the effective features from vibration signals for machinery fault diagnosis. This paper proposes a new manifold learning algorithm, joint global and local/nonlocal discriminant analysis (GLNDA), which aims to extract effective intrinsic geometrical information from the given vibration data. Comparisons with other regular methods, principal component analysis (PCA), local preserving projection (LPP), linear discriminant analysis (LDA) and local LDA (LLDA), illustrate the superiority of GLNDA in machinery fault diagnosis. Based on the extracted information by GLNDA, a GLNDA-based Fisher discriminant rule (FDR) is put forward and applied to machinery fault diagnosis without additional recognizer construction procedure. By importing Bagging into GLNDA score-based feature selection and FDR, a novel manifold ensemble method (selective GLNDA ensemble, SE-GLNDA) is investigated for machinery fault diagnosis. The motivation for developing ensemble of manifold learning components is that it can achieve higher accuracy and applicability than single component in machinery fault diagnosis. The effectiveness of the SE-GLNDA-based fault diagnosis method has been verified by experimental results from bearing full life testers.

  17. Faster native vowel discrimination learning in musicians is mediated by an optimization of mnemonic functions.

    Science.gov (United States)

    Elmer, Stefan; Greber, Marielle; Pushparaj, Arethy; Kühnis, Jürg; Jäncke, Lutz

    2017-09-01

    The ability to discriminate phonemes varying in spectral and temporal attributes constitutes one of the most basic intrinsic elements underlying language learning mechanisms. Since previous work has consistently shown that professional musicians are characterized by perceptual and cognitive advantages in a variety of language-related tasks, and since vowels can be considered musical sounds within the domain of speech, here we investigated the behavioral and electrophysiological correlates of native vowel discrimination learning in a sample of professional musicians and non-musicians. We evaluated the contribution of both the neurophysiological underpinnings of perceptual (i.e., N1/P2 complex) and mnemonic functions (i.e., N400 and P600 responses) while the participants were instructed to judge whether pairs of native consonant-vowel (CV) syllables manipulated in the first formant transition of the vowel (i.e., from /tu/ to /to/) were identical or not. Results clearly demonstrated faster learning in musicians, compared to non-musicians, as reflected by shorter reaction times and higher accuracy. Most notably, in terms of morphology, time course, and voltage strength, this steeper learning curve was accompanied by distinctive N400 and P600 manifestations between the two groups. In contrast, we did not reveal any group differences during the early stages of auditory processing (i.e., N1/P2 complex), suggesting that faster learning was mediated by an optimization of mnemonic but not perceptual functions. Based on a clear taxonomy of the mnemonic functions involved in the task, results are interpreted as pointing to a relationship between faster learning mechanisms in musicians and an optimization of echoic (i.e., N400 component) and working memory (i.e., P600 component) functions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Cross-label Suppression: a Discriminative and Fast Dictionary Learning with Group Regularization.

    Science.gov (United States)

    Wang, Xiudong; Gu, Yuantao

    2017-05-10

    This paper addresses image classification through learning a compact and discriminative dictionary efficiently. Given a structured dictionary with each atom (columns in the dictionary matrix) related to some label, we propose crosslabel suppression constraint to enlarge the difference among representations for different classes. Meanwhile, we introduce group regularization to enforce representations to preserve label properties of original samples, meaning the representations for the same class are encouraged to be similar. Upon the cross-label suppression, we don't resort to frequently-used `0-norm or `1- norm for coding, and obtain computational efficiency without losing the discriminative power for categorization. Moreover, two simple classification schemes are also developed to take full advantage of the learnt dictionary. Extensive experiments on six data sets including face recognition, object categorization, scene classification, texture recognition and sport action categorization are conducted, and the results show that the proposed approach can outperform lots of recently presented dictionary algorithms on both recognition accuracy and computational efficiency.

  19. Sparse representation for infrared Dim target detection via a discriminative over-complete dictionary learned online.

    Science.gov (United States)

    Li, Zheng-Zhou; Chen, Jing; Hou, Qian; Fu, Hong-Xia; Dai, Zhen; Jin, Gang; Li, Ru-Zhang; Liu, Chang-Ju

    2014-05-27

    It is difficult for structural over-complete dictionaries such as the Gabor function and discriminative over-complete dictionary, which are learned offline and classified manually, to represent natural images with the goal of ideal sparseness and to enhance the difference between background clutter and target signals. This paper proposes an infrared dim target detection approach based on sparse representation on a discriminative over-complete dictionary. An adaptive morphological over-complete dictionary is trained and constructed online according to the content of infrared image by K-singular value decomposition (K-SVD) algorithm. Then the adaptive morphological over-complete dictionary is divided automatically into a target over-complete dictionary describing target signals, and a background over-complete dictionary embedding background by the criteria that the atoms in the target over-complete dictionary could be decomposed more sparsely based on a Gaussian over-complete dictionary than the one in the background over-complete dictionary. This discriminative over-complete dictionary can not only capture significant features of background clutter and dim targets better than a structural over-complete dictionary, but also strengthens the sparse feature difference between background and target more efficiently than a discriminative over-complete dictionary learned offline and classified manually. The target and background clutter can be sparsely decomposed over their corresponding over-complete dictionaries, yet couldn't be sparsely decomposed based on their opposite over-complete dictionary, so their residuals after reconstruction by the prescribed number of target and background atoms differ very visibly. Some experiments are included and the results show that this proposed approach could not only improve the sparsity more efficiently, but also enhance the performance of small target detection more effectively.

  20. Sparse Representation for Infrared Dim Target Detection via a Discriminative Over-Complete Dictionary Learned Online

    Directory of Open Access Journals (Sweden)

    Zheng-Zhou Li

    2014-05-01

    Full Text Available It is difficult for structural over-complete dictionaries such as the Gabor function and discriminative over-complete dictionary, which are learned offline and classified manually, to represent natural images with the goal of ideal sparseness and to enhance the difference between background clutter and target signals. This paper proposes an infrared dim target detection approach based on sparse representation on a discriminative over-complete dictionary. An adaptive morphological over-complete dictionary is trained and constructed online according to the content of infrared image by K-singular value decomposition (K-SVD algorithm. Then the adaptive morphological over-complete dictionary is divided automatically into a target over-complete dictionary describing target signals, and a background over-complete dictionary embedding background by the criteria that the atoms in the target over-complete dictionary could be decomposed more sparsely based on a Gaussian over-complete dictionary than the one in the background over-complete dictionary. This discriminative over-complete dictionary can not only capture significant features of background clutter and dim targets better than a structural over-complete dictionary, but also strengthens the sparse feature difference between background and target more efficiently than a discriminative over-complete dictionary learned offline and classified manually. The target and background clutter can be sparsely decomposed over their corresponding over-complete dictionaries, yet couldn’t be sparsely decomposed based on their opposite over-complete dictionary, so their residuals after reconstruction by the prescribed number of target and background atoms differ very visibly. Some experiments are included and the results show that this proposed approach could not only improve the sparsity more efficiently, but also enhance the performance of small target detection more effectively.

  1. Improved Discriminability of Spatiotemporal Neural Patterns in Rat Motor Cortical Areas as Directional Choice Learning Progresses

    Directory of Open Access Journals (Sweden)

    Hongwei eMao

    2015-03-01

    Full Text Available Animals learn to choose a proper action among alternatives to improve their odds of success in food foraging and other activities critical for survival. Through trial-and-error, they learn correct associations between their choices and external stimuli. While a neural network that underlies such learning process has been identified at a high level, it is still unclear how individual neurons and a neural ensemble adapt as learning progresses. In this study, we monitored the activity of single units in the rat medial and lateral agranular (AGm and AGl, respectively areas as rats learned to make a left or right side lever press in response to a left or right side light cue. We noticed that rat movement parameters during the performance of the directional choice task quickly became stereotyped during the first 2-3 days or sessions. But learning the directional choice problem took weeks to occur. Accompanying rats’ behavioral performance adaptation, we observed neural modulation by directional choice in recorded single units. Our analysis shows that ensemble mean firing rates in the cue-on period did not change significantly as learning progressed, and the ensemble mean rate difference between left and right side choices did not show a clear trend of change either. However, the spatiotemporal firing patterns of the neural ensemble exhibited improved discriminability between the two directional choices through learning. These results suggest a spatiotemporal neural coding scheme in a motor cortical neural ensemble that may be responsible for and contributing to learning the directional choice task.

  2. From bird to sparrow: Learning-induced modulations in fine-grained semantic discrimination.

    Science.gov (United States)

    De Meo, Rosanna; Bourquin, Nathalie M-P; Knebel, Jean-François; Murray, Micah M; Clarke, Stephanie

    2015-09-01

    Recognition of environmental sounds is believed to proceed through discrimination steps from broad to more narrow categories. Very little is known about the neural processes that underlie fine-grained discrimination within narrow categories or about their plasticity in relation to newly acquired expertise. We investigated how the cortical representation of birdsongs is modulated by brief training to recognize individual species. During a 60-minute session, participants learned to recognize a set of birdsongs; they improved significantly their performance for trained (T) but not control species (C), which were counterbalanced across participants. Auditory evoked potentials (AEPs) were recorded during pre- and post-training sessions. Pre vs. post changes in AEPs were significantly different between T and C i) at 206-232ms post stimulus onset within a cluster on the anterior part of the left superior temporal gyrus; ii) at 246-291ms in the left middle frontal gyrus; and iii) 512-545ms in the left middle temporal gyrus as well as bilaterally in the cingulate cortex. All effects were driven by weaker activity for T than C species. Thus, expertise in discriminating T species modulated early stages of semantic processing, during and immediately after the time window that sustains the discrimination between human vs. animal vocalizations. Moreover, the training-induced plasticity is reflected by the sharpening of a left lateralized semantic network, including the anterior part of the temporal convexity and the frontal cortex. Training to identify birdsongs influenced, however, also the processing of C species, but at a much later stage. Correct discrimination of untrained sounds seems to require an additional step which results from lower-level features analysis such as apperception. We therefore suggest that the access to objects within an auditory semantic category is different and depends on subject's level of expertise. More specifically, correct intra

  3. Deformable segmentation of 3D MR prostate images via distributed discriminative dictionary and ensemble learning

    Science.gov (United States)

    Guo, Yanrong; Gao, Yaozong; Shao, Yeqin; Price, True; Oto, Aytekin; Shen, Dinggang

    2014-01-01

    Purpose: Automatic prostate segmentation from MR images is an important task in various clinical applications such as prostate cancer staging and MR-guided radiotherapy planning. However, the large appearance and shape variations of the prostate in MR images make the segmentation problem difficult to solve. Traditional Active Shape/Appearance Model (ASM/AAM) has limited accuracy on this problem, since its basic assumption, i.e., both shape and appearance of the targeted organ follow Gaussian distributions, is invalid in prostate MR images. To this end, the authors propose a sparse dictionary learning method to model the image appearance in a nonparametric fashion and further integrate the appearance model into a deformable segmentation framework for prostate MR segmentation. Methods: To drive the deformable model for prostate segmentation, the authors propose nonparametric appearance and shape models. The nonparametric appearance model is based on a novel dictionary learning method, namely distributed discriminative dictionary (DDD) learning, which is able to capture fine distinctions in image appearance. To increase the differential power of traditional dictionary-based classification methods, the authors' DDD learning approach takes three strategies. First, two dictionaries for prostate and nonprostate tissues are built, respectively, using the discriminative features obtained from minimum redundancy maximum relevance feature selection. Second, linear discriminant analysis is employed as a linear classifier to boost the optimal separation between prostate and nonprostate tissues, based on the representation residuals from sparse representation. Third, to enhance the robustness of the authors' classification method, multiple local dictionaries are learned for local regions along the prostate boundary (each with small appearance variations), instead of learning one global classifier for the entire prostate. These discriminative dictionaries are located on different

  4. Deformable segmentation of 3D MR prostate images via distributed discriminative dictionary and ensemble learning

    International Nuclear Information System (INIS)

    Guo, Yanrong; Shao, Yeqin; Gao, Yaozong; Price, True; Oto, Aytekin; Shen, Dinggang

    2014-01-01

    Purpose: Automatic prostate segmentation from MR images is an important task in various clinical applications such as prostate cancer staging and MR-guided radiotherapy planning. However, the large appearance and shape variations of the prostate in MR images make the segmentation problem difficult to solve. Traditional Active Shape/Appearance Model (ASM/AAM) has limited accuracy on this problem, since its basic assumption, i.e., both shape and appearance of the targeted organ follow Gaussian distributions, is invalid in prostate MR images. To this end, the authors propose a sparse dictionary learning method to model the image appearance in a nonparametric fashion and further integrate the appearance model into a deformable segmentation framework for prostate MR segmentation. Methods: To drive the deformable model for prostate segmentation, the authors propose nonparametric appearance and shape models. The nonparametric appearance model is based on a novel dictionary learning method, namely distributed discriminative dictionary (DDD) learning, which is able to capture fine distinctions in image appearance. To increase the differential power of traditional dictionary-based classification methods, the authors' DDD learning approach takes three strategies. First, two dictionaries for prostate and nonprostate tissues are built, respectively, using the discriminative features obtained from minimum redundancy maximum relevance feature selection. Second, linear discriminant analysis is employed as a linear classifier to boost the optimal separation between prostate and nonprostate tissues, based on the representation residuals from sparse representation. Third, to enhance the robustness of the authors' classification method, multiple local dictionaries are learned for local regions along the prostate boundary (each with small appearance variations), instead of learning one global classifier for the entire prostate. These discriminative dictionaries are located on

  5. Deformable segmentation of 3D MR prostate images via distributed discriminative dictionary and ensemble learning.

    Science.gov (United States)

    Guo, Yanrong; Gao, Yaozong; Shao, Yeqin; Price, True; Oto, Aytekin; Shen, Dinggang

    2014-07-01

    Automatic prostate segmentation from MR images is an important task in various clinical applications such as prostate cancer staging and MR-guided radiotherapy planning. However, the large appearance and shape variations of the prostate in MR images make the segmentation problem difficult to solve. Traditional Active Shape/Appearance Model (ASM/AAM) has limited accuracy on this problem, since its basic assumption, i.e., both shape and appearance of the targeted organ follow Gaussian distributions, is invalid in prostate MR images. To this end, the authors propose a sparse dictionary learning method to model the image appearance in a nonparametric fashion and further integrate the appearance model into a deformable segmentation framework for prostate MR segmentation. To drive the deformable model for prostate segmentation, the authors propose nonparametric appearance and shape models. The nonparametric appearance model is based on a novel dictionary learning method, namely distributed discriminative dictionary (DDD) learning, which is able to capture fine distinctions in image appearance. To increase the differential power of traditional dictionary-based classification methods, the authors' DDD learning approach takes three strategies. First, two dictionaries for prostate and nonprostate tissues are built, respectively, using the discriminative features obtained from minimum redundancy maximum relevance feature selection. Second, linear discriminant analysis is employed as a linear classifier to boost the optimal separation between prostate and nonprostate tissues, based on the representation residuals from sparse representation. Third, to enhance the robustness of the authors' classification method, multiple local dictionaries are learned for local regions along the prostate boundary (each with small appearance variations), instead of learning one global classifier for the entire prostate. These discriminative dictionaries are located on different patches of the

  6. Cross-modal effects on learning: a seismic stimulus improves color discrimination learning in a jumping spider.

    Science.gov (United States)

    VanderSal, Nicole D; Hebets, Eileen A

    2007-10-01

    The production of multimodal signals during animal displays is extremely common, and the function of such complex signaling has received much attention. Currently, the most frequently explored hypotheses regarding the evolution and function of complex signaling focus on the signal and/or signaler, or the signaling environment, while much less attention has been placed on the receivers. However, recent studies using vertebrates suggest that receiver psychology (e.g. learning and memory) may play a large role in the evolution of complex signaling. To date, the influence of multimodal cues on receiver learning and/or memory has not been studied in invertebrates. Here, we test the hypothesis that the presence of a seismic (vibratory) stimulus improves color discrimination learning in the jumping spider Habronattus dossenus. Using a heat-aversion learning experiment, we found evidence for a cross-modal effect on color learning. Over a series of training trials, individuals exposed to a seismic stimulus jumped onto the heated color less frequently and remained there for less time than did individuals not exposed to a seismic stimulus. In addition, in a final no-heat test trial, individuals from the seismic-present treatment were more likely to avoid the previously heated color than were individuals from the seismic-absent treatment. This is the first study to demonstrate a cross-modal influence on learning in an invertebrate.

  7. Vessel segmentation and microaneurysm detection using discriminative dictionary learning and sparse representation.

    Science.gov (United States)

    Javidi, Malihe; Pourreza, Hamid-Reza; Harati, Ahad

    2017-02-01

    Diabetic retinopathy (DR) is a major cause of visual impairment, and the analysis of retinal image can assist patients to take action earlier when it is more likely to be effective. The accurate segmentation of blood vessels in the retinal image can diagnose DR directly. In this paper, a novel scheme for blood vessel segmentation based on discriminative dictionary learning (DDL) and sparse representation has been proposed. The proposed system yields a strong representation which contains the semantic concept of the image. To extract blood vessel, two separate dictionaries, for vessel and non-vessel, capable of providing reconstructive and discriminative information of the retinal image are learned. In the test step, an unseen retinal image is divided into overlapping patches and classified to vessel and non-vessel patches. Then, a voting scheme is applied to generate the binary vessel map. The proposed vessel segmentation method can achieve the accuracy of 95% and a sensitivity of 75% in the same range of specificity 97% on two public datasets. The results show that the proposed method can achieve comparable results to existing methods and decrease false positive vessels in abnormal retinal images with pathological regions. Microaneurysm (MA) is the earliest sign of DR that appears as a small red dot on the surface of the retina. Despite several attempts to develop automated MA detection systems, it is still a challenging problem. In this paper, a method for MA detection, which is similar to our vessel segmentation approach, is proposed. In our method, a candidate detection algorithm based on the Morlet wavelet is applied to identify all possible MA candidates. In the next step, two discriminative dictionaries with the ability to distinguish MA from non-MA object are learned. These dictionaries are then used to classify the detected candidate objects. The evaluations indicate that the proposed MA detection method achieves higher average sensitivity about 2

  8. Rapid generation of balanced trial distributions for discrimination learning procedures: a technical note.

    Science.gov (United States)

    Gerard, Christophe J; Mackay, Harry A; Thompson, Brooks; McIlvane, William J

    2014-01-01

    We describe novel computer algorithms for rapid, sometimes virtually instantaneous generation of trial sequences needed to instrument many behavioral research procedures. Implemented on typical desktop or laptop computers, the algorithms impose constraints to forestall development of undesired stimulus control by position, recent trial outcomes, and other variables that could impede simple and conditional discrimination learning. They yield trial-by-trial lists of sequences that can serve (1) as inputs to procedure control software or (2) in generating templates for constructing sessions for implementation by hand or machine. © Society for the Experimental Analysis of Behavior.

  9. Different levels of food restriction reveal genotype-specific differences in learning a visual discrimination task.

    Directory of Open Access Journals (Sweden)

    Kalina Makowiecki

    Full Text Available In behavioural experiments, motivation to learn can be achieved using food rewards as positive reinforcement in food-restricted animals. Previous studies reduce animal weights to 80-90% of free-feeding body weight as the criterion for food restriction. However, effects of different degrees of food restriction on task performance have not been assessed. We compared learning task performance in mice food-restricted to 80 or 90% body weight (BW. We used adult wildtype (WT; C57Bl/6j and knockout (ephrin-A2⁻/⁻ mice, previously shown to have a reverse learning deficit. Mice were trained in a two-choice visual discrimination task with food reward as positive reinforcement. When mice reached criterion for one visual stimulus (80% correct in three consecutive 10 trial sets they began the reverse learning phase, where the rewarded stimulus was switched to the previously incorrect stimulus. For the initial learning and reverse phase of the task, mice at 90%BW took almost twice as many trials to reach criterion as mice at 80%BW. Furthermore, WT 80 and 90%BW groups significantly differed in percentage correct responses and learning strategy in the reverse learning phase, whereas no differences between weight restriction groups were observed in ephrin-A2⁻/⁻ mice. Most importantly, genotype-specific differences in reverse learning strategy were only detected in the 80%BW groups. Our results indicate that increased food restriction not only results in better performance and a shorter training period, but may also be necessary for revealing behavioural differences between experimental groups. This has important ethical and animal welfare implications when deciding extent of diet restriction in behavioural studies.

  10. A novel perceptual discrimination training task: Reducing fear overgeneralization in the context of fear learning.

    Science.gov (United States)

    Ginat-Frolich, Rivkah; Klein, Zohar; Katz, Omer; Shechner, Tomer

    2017-06-01

    Generalization is an adaptive learning mechanism, but it can be maladaptive when it occurs in excess. A novel perceptual discrimination training task was therefore designed to moderate fear overgeneralization. We hypothesized that improvement in basic perceptual discrimination would translate into lower fear overgeneralization in affective cues. Seventy adults completed a fear-conditioning task prior to being allocated into training or placebo groups. Predesignated geometric shape pairs were constructed for the training task. A target shape from each pair was presented. Thereafter, participants in the training group were shown both shapes and asked to identify the image that differed from the target. Placebo task participants only indicated the location of each shape on the screen. All participants then viewed new geometric pairs and indicated whether they were identical or different. Finally, participants completed a fear generalization test consisting of perceptual morphs ranging from the CS + to the CS-. Fear-conditioning was observed through physiological and behavioural measures. Furthermore, the training group performed better than the placebo group on the assessment task and exhibited decreased fear generalization in response to threat/safety cues. The findings offer evidence for the effectiveness of the novel discrimination training task, setting the stage for future research with clinical populations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. PROBABILISTIC PROGRAMMING FOR ADVANCED MACHINE LEARNING (PPAML) DISCRIMINATIVE LEARNING FOR GENERATIVE TASKS (DILIGENT)

    Science.gov (United States)

    2017-11-29

    the corresponding statistical quantities is formulated according to its definition , which involves the corresponding Fredholm integral equation. This...generative and discriminative areas: • Generative models: a novel framework for most accurate computation of key statistical elements of model...and data-driven ones: • Generative models: a novel framework for most accurate computation of key statistical elements of model-driven problems (such

  12. Accurate classification of brain gliomas by discriminate dictionary learning based on projective dictionary pair learning of proton magnetic resonance spectra.

    Science.gov (United States)

    Adebileje, Sikiru Afolabi; Ghasemi, Keyvan; Aiyelabegan, Hammed Tanimowo; Saligheh Rad, Hamidreza

    2017-04-01

    Proton magnetic resonance spectroscopy is a powerful noninvasive technique that complements the structural images of cMRI, which aids biomedical and clinical researches, by identifying and visualizing the compositions of various metabolites within the tissues of interest. However, accurate classification of proton magnetic resonance spectroscopy is still a challenging issue in clinics due to low signal-to-noise ratio, overlapping peaks of metabolites, and the presence of background macromolecules. This paper evaluates the performance of a discriminate dictionary learning classifiers based on projective dictionary pair learning method for brain gliomas proton magnetic resonance spectroscopy spectra classification task, and the result were compared with the sub-dictionary learning methods. The proton magnetic resonance spectroscopy data contain a total of 150 spectra (74 healthy, 23 grade II, 23 grade III, and 30 grade IV) from two databases. The datasets from both databases were first coupled together, followed by column normalization. The Kennard-Stone algorithm was used to split the datasets into its training and test sets. Performance comparison based on the overall accuracy, sensitivity, specificity, and precision was conducted. Based on the overall accuracy of our classification scheme, the dictionary pair learning method was found to outperform the sub-dictionary learning methods 97.78% compared with 68.89%, respectively. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  13. Does Fine Color Discrimination Learning in Free-Flying Honeybees Change Mushroom-Body Calyx Neuroarchitecture?

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    Frank M J Sommerlandt

    Full Text Available Honeybees learn color information of rewarding flowers and recall these memories in future decisions. For fine color discrimination, bees require differential conditioning with a concurrent presentation of target and distractor stimuli to form a long-term memory. Here we investigated whether the long-term storage of color information shapes the neural network of microglomeruli in the mushroom body calyces and if this depends on the type of conditioning. Free-flying honeybees were individually trained to a pair of perceptually similar colors in either absolute conditioning towards one of the colors or in differential conditioning with both colors. Subsequently, bees of either conditioning groups were tested in non-rewarded discrimination tests with the two colors. Only bees trained with differential conditioning preferred the previously learned color, whereas bees of the absolute conditioning group, and a stimuli-naïve group, chose randomly among color stimuli. All bees were then kept individually for three days in the dark to allow for complete long-term memory formation. Whole-mount immunostaining was subsequently used to quantify variation of microglomeruli number and density in the mushroom-body lip and collar. We found no significant differences among groups in neuropil volumes and total microglomeruli numbers, but learning performance was negatively correlated with microglomeruli density in the absolute conditioning group. Based on these findings we aim to promote future research approaches combining behaviorally relevant color learning tests in honeybees under free-flight conditions with neuroimaging analysis; we also discuss possible limitations of this approach.

  14. Enhanced discriminative fear learning of phobia-irrelevant stimuli in spider-fearful individuals

    Directory of Open Access Journals (Sweden)

    Carina eMosig

    2014-10-01

    Full Text Available Avoidance is considered as a central hallmark of all anxiety disorders. The acquisition and expression of avoidance which leads to the maintenance and exacerbation of pathological fear is closely linked to Pavlovian and operant conditioning processes. Changes in conditionability might represent a key feature of all anxiety disorders but the exact nature of these alterations might vary across different disorders. To date, no information is available on specific changes in conditionability for disorder-irrelevant stimuli in specific phobia (SP. The first aim of this study was to investigate changes in fear acquisition and extinction in spider-fearful individuals as compared to non-fearful participants by using the de novo fear conditioning paradigm. Secondly, we aimed to determine whether differences in the magnitude of context-dependent fear retrieval exist between spider-fearful and non-fearful individuals. Our findings point to an enhanced fear discrimination in spider-fearful individuals as compared to non-fearful individuals at both the physiological and subjective level. The enhanced fear discrimination in spider-fearful individuals was neither mediated by increased state anxiety, depression, nor stress tension. Spider-fearful individuals displayed no changes in extinction learning and/or fear retrieval. Surprisingly, we found no evidence for context-dependent modulation of fear retrieval in either group. Here we provide first evidence that spider-fearful individuals show an enhanced discriminative fear learning of phobia-irrelevant (de novo stimuli. Our findings provide novel insights into the role of fear acquisition and expression for the development and maintenance of maladaptive responses in the course of SP.

  15. Effects of MK-801 on vicarious trial-and-error and reversal of olfactory discrimination learning in weanling rats.

    Science.gov (United States)

    Griesbach, G S; Hu, D; Amsel, A

    1998-12-01

    The effects of dizocilpine maleate (MK-801) on vicarious trial-and-error (VTE), and on simultaneous olfactory discrimination learning and its reversal, were observed in weanling rats. The term VTE was used by Tolman (The determiners of behavior at a choice point. Psychol. Rev. 1938;46:318-336), who described it as conflict-like behavior at a choice-point in simultaneous discrimination learning. It takes the form of head movements from one stimulus to the other, and has recently been proposed by Amsel (Hippocampal function in the rat: cognitive mapping or vicarious trial-and-error? Hippocampus, 1993;3:251-256) as related to hippocampal, nonspatial function during this learning. Weanling male rats received systemic MK-801 either 30 min before the onset of olfactory discrimination training and its reversal, or only before its reversal. The MK-801-treated animals needed significantly more sessions to acquire the discrimination and showed significantly fewer VTEs in the acquisition phase of learning. Impaired reversal learning was shown only when MK-801 was administered during the reversal-learning phase, itself, and not when it was administered throughout both phases.

  16. Development of vicarious trial-and-error behavior in odor discrimination learning in the rat: relation to hippocampal function?

    Science.gov (United States)

    Hu, D; Griesbach, G; Amsel, A

    1997-06-01

    Previous work from our laboratory has suggested that hippocampal electrolytic lesions result in a deficit in simultaneous, black-white discrimination learning and reduce the frequency of vicarious trial-and-error (VTE) at a choice-point. VTE is a term Tolman used to describe the rat's conflict-like behavior, moving its head from one stimulus to the other at a choice point, and has been proposed as a major nonspatial feature of hippocampal function in both visual and olfactory discrimination learning. Simultaneous odor discrimination and VTE behavior were examined at three different ages. The results were that 16-day-old pups made fewer VTEs and learned much more slowly than 30- and 60-day-olds, a finding in accord with levels of hippocampal maturity in the rat.

  17. Corpus linguistics and naive discriminative learning A linguística de corpus e a aprendizagem discriminativa ingênua

    Directory of Open Access Journals (Sweden)

    R. Harald Baayen

    2011-01-01

    Full Text Available Three classifiers from machine learning (the generalized linear mixed model, memory based learning, and support vector machines are compared with a naive discriminative learning classifier, derived from basic principles of error-driven learning characterizing animal and human learning. Tested on the dative alternation in English, using the Switchboard data from (BRESNAN; CUENI; NIKITINA; BAAYEN, 2007, naive discriminative learning emerges with stateof-the-art predictive accuracy. Naive discriminative learning offers a united framework for understanding the learning of probabilistic distributional patterns, for classification, and for a cognitive grounding of distinctive collexeme analysis.Três classificadores de aprendizagem de máquina (modelos mistos lineares generalizados, aprendizagem baseada na memória e máquinas de apoio a vetores são comparados com o classificador da aprendizagem discriminativa ingênua, derivada de princípios básicos da aprendizagem guiada por erros de humanos e animais. Testada na alternância dativa do inglês, usando os dados do Switchboard (BRESNAN; CUENI; NIKITINA; BAAYEN, 2007, a aprendizagem discriminativa ingênua emerge com uma acurácia predicativa no estado da arte. A aprendizagem discriminativa ingênua oferece um arcabouço unificado para a compreensão da aprendizagem de padrões distribucionais probabilísticos, para a classificação, e para um embasamento cognitivo para a análise de colexemas distintivos.

  18. Single pairing spike-timing dependent plasticity in BiFeO3 memristors with a time window of 25ms to 125µs

    Directory of Open Access Journals (Sweden)

    Nan eDu

    2015-06-01

    Full Text Available Memristive devices are popular among neuromorphic engineers for their ability to emulate forms of spike-driven synaptic plasticity by applying specific voltage and current waveforms at their two terminals. In this paper, we investigate spike-timing dependent plasticity (STDP with a single pairing of one presynaptic voltage spike and one postsynaptic voltage spike in a BiFeO3 memristive device. In most memristive materials the learning window is primarily a function of the material characteristics and not of the applied waveform. In contrast, we show that the analog resistive switching of the developed artificial synapses allows to adjust the learning time constant of the STDP function from 25ms to 125μs via the duration of applied voltage spikes. Also, as the induced weight change may degrade, we investigate the remanence of the resistance change for several hours after analog resistive switching, thus emulating the processes expected in biological synapses. As the power consumption is a major constraint in neuromorphic circuits, we show methods to reduce the consumed energy per setting pulse to only 4.5 pJ in the developed artificial synapses.

  19. Comparing behavioral discrimination and learning abilities in monolinguals, bilinguals and multilinguals.

    Science.gov (United States)

    Tremblay, Marie-Claude; Sabourin, Laura

    2012-11-01

    The aim of the experiment was to determine whether language learning experience contributes to the development of enhanced speech perception abilities. Monolinguals, bilinguals and multilinguals were compared in their ability to discriminate a non-native contrast behaviorally using an AX task. The experiment was based on a "pre-test-training-post-test" design and performance was tested before and after receiving training on the voiceless aspirated dental/retroflex stop contrast. At post-test, participants were also tested on their ability to transfer training to a similar contrast (i.e., voiceless unaspirated dental/retroflex stop contrast). While no group differences were found at pre-test, analyses of the trained-on contrast at post-test revealed that multilinguals were more accurate than monolinguals and that both the multilingual and bilingual groups were more accurate than a control group that received no training. The results of the experiment not only suggest that multilinguals and bilinguals have enhanced speech perception abilities compared to monolinguals, but they also indicate that bi-/multilingualism helps develop superior learning abilities. This provides support for the idea that learning more than one language has positive effects on the cognitive development of an individual (e.g., Bialystok et al., 2004).

  20. Enhanced flexibility of place discrimination learning by targeting striatal cholinergic interneurons.

    Science.gov (United States)

    Okada, Kana; Nishizawa, Kayo; Fukabori, Ryoji; Kai, Nobuyuki; Shiota, Akira; Ueda, Masatsugu; Tsutsui, Yuji; Sakata, Shogo; Matsushita, Natsuki; Kobayashi, Kazuto

    2014-05-06

    Behavioural flexibility is mediated through the neural circuitry linking the prefrontal cortex and basal ganglia. Here we conduct selective elimination of striatal cholinergic interneurons in transgenic rats by immunotoxin-mediated cell targeting. Elimination of cholinergic interneurons from the dorsomedial striatum (DMS), but not from the dorsolateral striatum, results in enhanced reversal and extinction learning, sparing the acquisition of place discrimination. This enhancement is prevented by infusion of a non-selective muscarinic acetylcholine receptor agonist into the DMS either in the acquisition, reversal or extinction phase. In addition, gene-specific silencing of M4 muscarinic receptor by lentiviral expression of short hairpin RNA (shRNA) mimics the place reversal learning promoted by cholinergic elimination, whereas shRNA-mediated gene silencing of M1 muscarinic receptor shows the normal performance of reversal learning. Our data indicate that DMS cholinergic interneurons inhibit behavioural flexibility, mainly through the M4 muscarinic receptor, suggesting that this role is engaged to the stabilization of acquired reward contingency and the suppression of response switch to changed contingency.

  1. Go/no-go discriminated avoidance learning in prenatally x-irradiated rats

    International Nuclear Information System (INIS)

    Tamaki, Y.; Inouye, M.

    1988-01-01

    Male Fischer344 rats were exposed to x-irradiation at a dose of 200 rad on Day 17 of gestation. Irradiated and control rats were tested at 10-13 weeks of age with the paradigm of go/no-go (active-passive) discriminated avoidance conditioning for three consecutive daily sessions. During the first conditioning session, they learned only active avoidance responses to two different warning signals. During the second and third sessions, they learned active and passive avoidance responses: in response to one warning signal, rats were required to make an active response to avoid a shock, but not to run in response to the other signal in order to avoid a shock. Prenatally irradiated rats made more active avoidance responses to both warning signals than controls (first session). In the early training phase of the go/no-go task, irradiated rats performed significantly higher active and lower passive avoidance responses than controls. Irradiated rats established a strong tendency to respond actively to the no-go signal, but eventually learned to respond to it

  2. Absence of binocular summation, eye dominance, and learning effects in color discrimination.

    Science.gov (United States)

    Costa, Marcelo Fernandes; Ventura, Dora Fix; Perazzolo, Felipe; Murakoshi, Marcio; Silveira, Luiz Carlos de Lima

    2006-01-01

    We evaluated binocular summation, eye dominance, and learning in the Trivector and Ellipses procedures of the Cambridge Colour Test (CCT). Subjects (n = 36, 18-30 years old) were recruited among students and staff from the University of São Paulo. Inclusion criteria were absence of ophthalmological complaints and best-corrected Snellen VA 20/20 or better. The subjects were tested in three randomly selected eye conditions: binocular, monocular dominant eye, and nondominant eye. Results obtained in the binocular and monocular conditions did not differ statistically for thresholds measured along the protan, deutan, and tritan confusion axes (ANOVA, P > 0.05). No statistical difference was detected among discrimination ellipses obtained in binocular or monocular conditions (ANOVA, P > 0.05), suggesting absence of binocular summation or of an effect of eye dominance. Possible effects of learning were examined by comparing successive thresholds obtained in the three testing conditions. There was no evidence of improvement as a function of testing order (ANCOVA, P > 0.05). We conclude that CCT thresholds are not affected by binocularity, eye dominance, or learning. Our results differ from those found by Verriest et al. (1982) using the Farnsworth-Munsell 100 Hue test and Hovis et al. (2004) using the Farnsworth-Munsell panel D-15 test.

  3. Improved neutron-gamma discrimination for a 3He neutron detector using subspace learning methods

    Science.gov (United States)

    Wang, C. L.; Funk, L. L.; Riedel, R. A.; Berry, K. D.

    2017-05-01

    3He gas based neutron Linear-Position-Sensitive Detectors (LPSDs) have been used for many neutron scattering instruments. Traditional Pulse-height Analysis (PHA) for Neutron-Gamma Discrimination (NGD) resulted in the neutron-gamma efficiency ratio (NGD ratio) on the order of 105-106. The NGD ratios of 3He detectors need to be improved for even better scientific results from neutron scattering. Digital Signal Processing (DSP) analyses of waveforms were proposed for obtaining better NGD ratios, based on features extracted from rise-time, pulse amplitude, charge integration, a simplified Wiener filter, and the cross-correlation between individual and template waveforms of neutron and gamma events. Fisher Linear Discriminant Analysis (FLDA) and three Multivariate Analyses (MVAs) of the features were performed. The NGD ratios are improved by about 102-103 times compared with the traditional PHA method. Our results indicate the NGD capabilities of 3He tube detectors can be significantly improved with subspace-learning based methods, which may result in a reduced data-collection time and better data quality for further data reduction.

  4. Automatic apical view classification of echocardiograms using a discriminative learning dictionary.

    Science.gov (United States)

    Khamis, Hanan; Zurakhov, Grigoriy; Azar, Vered; Raz, Adi; Friedman, Zvi; Adam, Dan

    2017-02-01

    As part of striving towards fully automatic cardiac functional assessment of echocardiograms, automatic classification of their standard views is essential as a pre-processing stage. The similarity among three of the routinely acquired longitudinal scans: apical two-chamber (A2C), apical four-chamber (A4C) and apical long-axis (ALX), and the noise commonly inherent to these scans - make the classification a challenge. Here we introduce a multi-stage classification algorithm that employs spatio-temporal feature extraction (Cuboid Detector) and supervised dictionary learning (LC-KSVD) approaches to uniquely enhance the automatic recognition and classification accuracy of echocardiograms. The algorithm incorporates both discrimination and labelling information to allow a discriminative and sparse representation of each view. The advantage of the spatio-temporal feature extraction as compared to spatial processing is then validated. A set of 309 clinical clips (103 for each view), were labeled by 2 experts. A subset of 70 clips of each class was used as a training set and the rest as a test set. The recognition accuracies achieved were: 97%, 91% and 97% of A2C, A4C and ALX respectively, with average recognition rate of 95%. Thus, automatic classification of echocardiogram views seems promising, despite the inter-view similarity between the classes and intra-view variability among clips belonging to the same class. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Statistical and Machine-Learning Classifier Framework to Improve Pulse Shape Discrimination System Design

    Energy Technology Data Exchange (ETDEWEB)

    Wurtz, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kaplan, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-28

    Pulse shape discrimination (PSD) is a variety of statistical classifier. Fully-­realized statistical classifiers rely on a comprehensive set of tools for designing, building, and implementing. PSD advances rely on improvements to the implemented algorithm. PSD advances can be improved by using conventional statistical classifier or machine learning methods. This paper provides the reader with a glossary of classifier-­building elements and their functions in a fully-­designed and operational classifier framework that can be used to discover opportunities for improving PSD classifier projects. This paper recommends reporting the PSD classifier’s receiver operating characteristic (ROC) curve and its behavior at a gamma rejection rate (GRR) relevant for realistic applications.

  6. A parallel spatiotemporal saliency and discriminative online learning method for visual target tracking in aerial videos.

    Science.gov (United States)

    Aghamohammadi, Amirhossein; Ang, Mei Choo; A Sundararajan, Elankovan; Weng, Ng Kok; Mogharrebi, Marzieh; Banihashem, Seyed Yashar

    2018-01-01

    Visual tracking in aerial videos is a challenging task in computer vision and remote sensing technologies due to appearance variation difficulties. Appearance variations are caused by camera and target motion, low resolution noisy images, scale changes, and pose variations. Various approaches have been proposed to deal with appearance variation difficulties in aerial videos, and amongst these methods, the spatiotemporal saliency detection approach reported promising results in the context of moving target detection. However, it is not accurate for moving target detection when visual tracking is performed under appearance variations. In this study, a visual tracking method is proposed based on spatiotemporal saliency and discriminative online learning methods to deal with appearance variations difficulties. Temporal saliency is used to represent moving target regions, and it was extracted based on the frame difference with Sauvola local adaptive thresholding algorithms. The spatial saliency is used to represent the target appearance details in candidate moving regions. SLIC superpixel segmentation, color, and moment features can be used to compute feature uniqueness and spatial compactness of saliency measurements to detect spatial saliency. It is a time consuming process, which prompted the development of a parallel algorithm to optimize and distribute the saliency detection processes that are loaded into the multi-processors. Spatiotemporal saliency is then obtained by combining the temporal and spatial saliencies to represent moving targets. Finally, a discriminative online learning algorithm was applied to generate a sample model based on spatiotemporal saliency. This sample model is then incrementally updated to detect the target in appearance variation conditions. Experiments conducted on the VIVID dataset demonstrated that the proposed visual tracking method is effective and is computationally efficient compared to state-of-the-art methods.

  7. Selective Increase of Auditory Cortico-Striatal Coherence during Auditory-Cued Go/NoGo Discrimination Learning

    Science.gov (United States)

    Schulz, Andreas L.; Woldeit, Marie L.; Gonçalves, Ana I.; Saldeitis, Katja; Ohl, Frank W.

    2016-01-01

    Goal directed behavior and associated learning processes are tightly linked to neuronal activity in the ventral striatum. Mechanisms that integrate task relevant sensory information into striatal processing during decision making and learning are implicitly assumed in current reinforcement models, yet they are still weakly understood. To identify the functional activation of cortico-striatal subpopulations of connections during auditory discrimination learning, we trained Mongolian gerbils in a two-way active avoidance task in a shuttlebox to discriminate between falling and rising frequency modulated tones with identical spectral properties. We assessed functional coupling by analyzing the field-field coherence between the auditory cortex and the ventral striatum of animals performing the task. During the course of training, we observed a selective increase of functional coupling during Go-stimulus presentations. These results suggest that the auditory cortex functionally interacts with the ventral striatum during auditory learning and that the strengthening of these functional connections is selectively goal-directed. PMID:26793085

  8. Selective increase of auditory cortico-striatal coherence during auditory-cued Go/NoGo discrimination learning.

    Directory of Open Access Journals (Sweden)

    Andreas L. Schulz

    2016-01-01

    Full Text Available Goal directed behavior and associated learning processes are tightly linked to neuronal activity in the ventral striatum. Mechanisms that integrate task relevant sensory information into striatal processing during decision making and learning are implicitly assumed in current reinforcementmodels, yet they are still weakly understood. To identify the functional activation of cortico-striatal subpopulations of connections during auditory discrimination learning, we trained Mongolian gerbils in a two-way active avoidance task in a shuttlebox to discriminate between falling and rising frequency modulated tones with identical spectral properties. We assessed functional coupling by analyzing the field-field coherence between the auditory cortex and the ventral striatum of animals performing the task. During the course of training, we observed a selective increase of functionalcoupling during Go-stimulus presentations. These results suggest that the auditory cortex functionally interacts with the ventral striatum during auditory learning and that the strengthening of these functional connections is selectively goal-directed.

  9. Discriminative learning of receptive fields from responses to non-Gaussian stimulus ensembles.

    Directory of Open Access Journals (Sweden)

    Arne F Meyer

    Full Text Available Analysis of sensory neurons' processing characteristics requires simultaneous measurement of presented stimuli and concurrent spike responses. The functional transformation from high-dimensional stimulus space to the binary space of spike and non-spike responses is commonly described with linear-nonlinear models, whose linear filter component describes the neuron's receptive field. From a machine learning perspective, this corresponds to the binary classification problem of discriminating spike-eliciting from non-spike-eliciting stimulus examples. The classification-based receptive field (CbRF estimation method proposed here adapts a linear large-margin classifier to optimally predict experimental stimulus-response data and subsequently interprets learned classifier weights as the neuron's receptive field filter. Computational learning theory provides a theoretical framework for learning from data and guarantees optimality in the sense that the risk of erroneously assigning a spike-eliciting stimulus example to the non-spike class (and vice versa is minimized. Efficacy of the CbRF method is validated with simulations and for auditory spectro-temporal receptive field (STRF estimation from experimental recordings in the auditory midbrain of Mongolian gerbils. Acoustic stimulation is performed with frequency-modulated tone complexes that mimic properties of natural stimuli, specifically non-Gaussian amplitude distribution and higher-order correlations. Results demonstrate that the proposed approach successfully identifies correct underlying STRFs, even in cases where second-order methods based on the spike-triggered average (STA do not. Applied to small data samples, the method is shown to converge on smaller amounts of experimental recordings and with lower estimation variance than the generalized linear model and recent information theoretic methods. Thus, CbRF estimation may prove useful for investigation of neuronal processes in response to

  10. Protective effect of the calcium antagonist nimodipine on discrimination learning deficits and impaired retention behavior caused by prenatal nitrite exposure in rats

    NARCIS (Netherlands)

    Nyakas, Csaba; Markel, Éva; Bohus, Béla; Schuurman, Teun; Luiten, Paulus

    1990-01-01

    Discrimination learning behavior and retention of a passive avoidance response were studied in male adult offspring of gestating rats exposed to drinking water containing 2 g/l sodium nitrite, throughout the second half of pregnancy. Both in an auditory and visual discrimination learning paradigm

  11. Learning to discriminate through long-term changes of dynamical synaptic transmission.

    Science.gov (United States)

    Leibold, Christian; Bendels, Michael H K

    2009-12-01

    Short-term synaptic plasticity is modulated by long-term synaptic changes. There is, however, no general agreement on the computational role of this interaction. Here, we derive a learning rule for the release probability and the maximal synaptic conductance in a circuit model with combined recurrent and feedforward connections that allows learning to discriminate among natural inputs. Short-term synaptic plasticity thereby provides a nonlinear expansion of the input space of a linear classifier, whereas the random recurrent network serves to decorrelate the expanded input space. Computer simulations reveal that the twofold increase in the number of input dimensions through short-term synaptic plasticity improves the performance of a standard perceptron up to 100%. The distributions of release probabilities and maximal synaptic conductances at the capacity limit strongly depend on the balance between excitation and inhibition. The model also suggests a new computational interpretation of spikes evoked by stimuli outside the classical receptive field. These neuronal activities may reflect decorrelation of the expanded stimulus space by intracortical synaptic connections.

  12. A possible structural correlate of learning performance on a colour discrimination task in the brain of the bumblebee

    Science.gov (United States)

    Li, Li; MaBouDi, HaDi; Egertová, Michaela; Elphick, Maurice R.

    2017-01-01

    Synaptic plasticity is considered to be a basis for learning and memory. However, the relationship between synaptic arrangements and individual differences in learning and memory is poorly understood. Here, we explored how the density of microglomeruli (synaptic complexes) within specific regions of the bumblebee (Bombus terrestris) brain relates to both visual learning and inter-individual differences in learning and memory performance on a visual discrimination task. Using whole-brain immunolabelling, we measured the density of microglomeruli in the collar region (visual association areas) of the mushroom bodies of the bumblebee brain. We found that bumblebees which made fewer errors during training in a visual discrimination task had higher microglomerular density. Similarly, bumblebees that had better retention of the learned colour-reward associations two days after training had higher microglomerular density. Further experiments indicated experience-dependent changes in neural circuitry: learning a colour-reward contingency with 10 colours (but not two colours) does result, and exposure to many different colours may result, in changes to microglomerular density in the collar region of the mushroom bodies. These results reveal the varying roles that visual experience, visual learning and foraging activity have on neural structure. Although our study does not provide a causal link between microglomerular density and performance, the observed positive correlations provide new insights for future studies into how neural structure may relate to inter-individual differences in learning and memory. PMID:28978727

  13. Improved object optimal synthetic description, modeling, learning, and discrimination by GEOGINE computational kernel

    Science.gov (United States)

    Fiorini, Rodolfo A.; Dacquino, Gianfranco

    2005-03-01

    GEOGINE (GEOmetrical enGINE), a state-of-the-art OMG (Ontological Model Generator) based on n-D Tensor Invariants for n-Dimensional shape/texture optimal synthetic representation, description and learning, was presented in previous conferences elsewhere recently. Improved computational algorithms based on the computational invariant theory of finite groups in Euclidean space and a demo application is presented. Progressive model automatic generation is discussed. GEOGINE can be used as an efficient computational kernel for fast reliable application development and delivery in advanced biomedical engineering, biometric, intelligent computing, target recognition, content image retrieval, data mining technological areas mainly. Ontology can be regarded as a logical theory accounting for the intended meaning of a formal dictionary, i.e., its ontological commitment to a particular conceptualization of the world object. According to this approach, "n-D Tensor Calculus" can be considered a "Formal Language" to reliably compute optimized "n-Dimensional Tensor Invariants" as specific object "invariant parameter and attribute words" for automated n-Dimensional shape/texture optimal synthetic object description by incremental model generation. The class of those "invariant parameter and attribute words" can be thought as a specific "Formal Vocabulary" learned from a "Generalized Formal Dictionary" of the "Computational Tensor Invariants" language. Even object chromatic attributes can be effectively and reliably computed from object geometric parameters into robust colour shape invariant characteristics. As a matter of fact, any highly sophisticated application needing effective, robust object geometric/colour invariant attribute capture and parameterization features, for reliable automated object learning and discrimination can deeply benefit from GEOGINE progressive automated model generation computational kernel performance. Main operational advantages over previous

  14. Magnetic field discrimination, learning, and memory in the yellow stingray (Urobatis jamaicensis).

    Science.gov (United States)

    Newton, Kyle C; Kajiura, Stephen M

    2017-07-01

    Elasmobranch fishes (sharks, skates, and rays) have been hypothesized to use the geomagnetic field as a cue for orienting and navigating across a wide range of spatial scales. Magnetoreception has been demonstrated in many invertebrate and vertebrate taxa, including elasmobranchs, but this sensory modality and the cognitive abilities of cartilaginous fishes are poorly studied. Wild caught yellow stingrays, Urobatis jamaicensis (N = 8), underwent conditioning to associate a magnetic stimulus with a food reward in order to elicit foraging behaviors. Behavioral conditioning consisted of burying magnets and non-magnetic controls at random locations within a test arena and feeding stingrays as they passed over the hidden magnets. The location of the magnets and controls was changed for each trial, and all confounding sensory cues were eliminated. The stingrays learned to discriminate the magnetic stimuli within a mean of 12.6 ± 0.7 SE training sessions of four trials per session. Memory probes were conducted at intervals between 90 and 180 days post-learning criterion, and six of eight stingrays completed the probes with a ≥75% success rate and minimum latency to complete the task. These results show the fastest rate of learning and longest memory window for any batoid (skate or ray) to date. This study demonstrates that yellow stingrays, and possibly other elasmobranchs, can use a magnetic stimulus as a geographic marker for the location of resources and is an important step toward understanding whether these fishes use geomagnetic cues during spatial navigation tasks in the natural environment.

  15. Effects of X-Ray Radiation on Complex Visual Discrimination Learning and Social Recognition Memory in Rats

    Science.gov (United States)

    Davis, Catherine M.; Roma, Peter G.; Armour, Elwood; Gooden, Virginia L.; Brady, Joseph V.; Weed, Michael R.; Hienz, Robert D.

    2014-01-01

    The present report describes an animal model for examining the effects of radiation on a range of neurocognitive functions in rodents that are similar to a number of basic human cognitive functions. Fourteen male Long-Evans rats were trained to perform an automated intra-dimensional set shifting task that consisted of their learning a basic discrimination between two stimulus shapes followed by more complex discrimination stages (e.g., a discrimination reversal, a compound discrimination, a compound reversal, a new shape discrimination, and an intra-dimensional stimulus discrimination reversal). One group of rats was exposed to head-only X-ray radiation (2.3 Gy at a dose rate of 1.9 Gy/min), while a second group received a sham-radiation exposure using the same anesthesia protocol. The irradiated group responded less, had elevated numbers of omitted trials, increased errors, and greater response latencies compared to the sham-irradiated control group. Additionally, social odor recognition memory was tested after radiation exposure by assessing the degree to which rats explored wooden beads impregnated with either their own odors or with the odors of novel, unfamiliar rats; however, no significant effects of radiation on social odor recognition memory were observed. These data suggest that rodent tasks assessing higher-level human cognitive domains are useful in examining the effects of radiation on the CNS, and may be applicable in approximating CNS risks from radiation exposure in clinical populations receiving whole brain irradiation. PMID:25099152

  16. Effects of X-ray radiation on complex visual discrimination learning and social recognition memory in rats.

    Directory of Open Access Journals (Sweden)

    Catherine M Davis

    Full Text Available The present report describes an animal model for examining the effects of radiation on a range of neurocognitive functions in rodents that are similar to a number of basic human cognitive functions. Fourteen male Long-Evans rats were trained to perform an automated intra-dimensional set shifting task that consisted of their learning a basic discrimination between two stimulus shapes followed by more complex discrimination stages (e.g., a discrimination reversal, a compound discrimination, a compound reversal, a new shape discrimination, and an intra-dimensional stimulus discrimination reversal. One group of rats was exposed to head-only X-ray radiation (2.3 Gy at a dose rate of 1.9 Gy/min, while a second group received a sham-radiation exposure using the same anesthesia protocol. The irradiated group responded less, had elevated numbers of omitted trials, increased errors, and greater response latencies compared to the sham-irradiated control group. Additionally, social odor recognition memory was tested after radiation exposure by assessing the degree to which rats explored wooden beads impregnated with either their own odors or with the odors of novel, unfamiliar rats; however, no significant effects of radiation on social odor recognition memory were observed. These data suggest that rodent tasks assessing higher-level human cognitive domains are useful in examining the effects of radiation on the CNS, and may be applicable in approximating CNS risks from radiation exposure in clinical populations receiving whole brain irradiation.

  17. The relationship between pronunciation and listening discrimination when Japanese natives are learning English.

    Science.gov (United States)

    Shimamune, S; Smith, S L

    1995-01-01

    Two Japanese students were taught to pronounce and discriminate English words that contain unfamiliar phonemic contrasts (e.g., rock and lock). Teaching pronunciation was found to be easier than teaching listening discrimination. Teaching listening discrimination resulted in collateral improvement in pronunciation and, to a lesser extent, vice versa.

  18. Discriminative Structured Dictionary Learning on Grassmann Manifolds and Its Application on Image Restoration.

    Science.gov (United States)

    Pan, Han; Jing, Zhongliang; Qiao, Lingfeng; Li, Minzhe

    2017-09-25

    Image restoration is a difficult and challenging problem in various imaging applications. However, despite of the benefits of a single overcomplete dictionary, there are still several challenges for capturing the geometric structure of image of interest. To more accurately represent the local structures of the underlying signals, we propose a new problem formulation for sparse representation with block-orthogonal constraint. There are three contributions. First, a framework for discriminative structured dictionary learning is proposed, which leads to a smooth manifold structure and quotient search spaces. Second, an alternating minimization scheme is proposed after taking both the cost function and the constraints into account. This is achieved by iteratively alternating between updating the block structure of the dictionary defined on Grassmann manifold and sparsifying the dictionary atoms automatically. Third, Riemannian conjugate gradient is considered to track local subspaces efficiently with a convergence guarantee. Extensive experiments on various datasets demonstrate that the proposed method outperforms the state-of-the-art methods on the removal of mixed Gaussian-impulse noise.

  19. Early auditory enrichment with music enhances auditory discrimination learning and alters NR2B protein expression in rat auditory cortex.

    Science.gov (United States)

    Xu, Jinghong; Yu, Liping; Cai, Rui; Zhang, Jiping; Sun, Xinde

    2009-01-03

    Previous studies have shown that the functional development of auditory system is substantially influenced by the structure of environmental acoustic inputs in early life. In our present study, we investigated the effects of early auditory enrichment with music on rat auditory discrimination learning. We found that early auditory enrichment with music from postnatal day (PND) 14 enhanced learning ability in auditory signal-detection task and in sound duration-discrimination task. In parallel, a significant increase was noted in NMDA receptor subunit NR2B protein expression in the auditory cortex. Furthermore, we found that auditory enrichment with music starting from PND 28 or 56 did not influence NR2B expression in the auditory cortex. No difference was found in the NR2B expression in the inferior colliculus (IC) between music-exposed and normal rats, regardless of when the auditory enrichment with music was initiated. Our findings suggest that early auditory enrichment with music influences NMDA-mediated neural plasticity, which results in enhanced auditory discrimination learning.

  20. Wavelet transform and real-time learning method for myoelectric signal in motion discrimination

    International Nuclear Information System (INIS)

    Liu Haihua; Chen Xinhao; Chen Yaguang

    2005-01-01

    This paper discusses the applicability of the Wavelet transform for analyzing an EMG signal and discriminating motion classes. In many previous works, researchers have dealt with steady EMG and have proposed suitable analyzing methods for the EMG, for example FFT and STFT. Therefore, it is difficult for the previous approaches to discriminate motions from the EMG in the different phases of muscle activity, i.e., pre-activity, in activity, postactivity phases, as well as the period of motion transition from one to another. In this paper, we introduce the Wavelet transform using the Coiflet mother wavelet into our real-time EMG prosthetic hand controller for discriminating motions from steady and unsteady EMG. A preliminary experiment to discriminate three hand motions from four channel EMG in the initial pre-activity and in activity phase is carried out to show the effectiveness of the approach. However, future research efforts are necessary to discriminate more motions much precisely

  1. Transfer of perceptual learning of depth discrimination between local and global stereograms.

    Science.gov (United States)

    Gantz, Liat; Bedell, Harold E

    2010-08-23

    Several previous studies reported differences when stereothresholds are assessed with local-contour stereograms vs. complex random-dot stereograms (RDSs). Dissimilar thresholds may be due to differences in the properties of the stereograms (e.g. spatial frequency content, contrast, inter-element separation, area) or to different underlying processing mechanisms. This study examined the transfer of perceptual learning of depth discrimination between local and global RDSs with similar properties, and vice versa. If global and local stereograms are processed by separate neural mechanisms, then the magnitude and rate of training for the two types of stimuli are likely to differ, and the transfer of training from one stimulus type to the other should be minimal. Based on previous results, we chose RDSs with element densities of 0.17% and 28.3% to serve as the local and global stereograms, respectively. Fourteen inexperienced subjects with normal binocular vision were randomly assigned to either a local- or global- RDS training group. Stereothresholds for both stimulus types were measured before and after 7700 training trials distributed over 10 sessions. Stereothresholds for the trained condition improve for approximately 3000 trials, by an average of 0.36+/-0.08 for local and 0.29+/-0.10 for global RDSs, and level off thereafter. Neither the rate nor the magnitude of improvement differ statistically between the local- and global-training groups. Further, no significant difference exists in the amount of improvement on the trained vs. the untrained targets for either training group. These results are consistent with the operation of a single mechanism to process both local and global stereograms. Copyright 2010 Elsevier Ltd. All rights reserved.

  2. Confidence-Based Data Association and Discriminative Deep Appearance Learning for Robust Online Multi-Object Tracking.

    Science.gov (United States)

    Bae, Seung-Hwan; Yoon, Kuk-Jin

    2018-03-01

    Online multi-object tracking aims at estimating the tracks of multiple objects instantly with each incoming frame and the information provided up to the moment. It still remains a difficult problem in complex scenes, because of the large ambiguity in associating multiple objects in consecutive frames and the low discriminability between objects appearances. In this paper, we propose a robust online multi-object tracking method that can handle these difficulties effectively. We first define the tracklet confidence using the detectability and continuity of a tracklet, and decompose a multi-object tracking problem into small subproblems based on the tracklet confidence. We then solve the online multi-object tracking problem by associating tracklets and detections in different ways according to their confidence values. Based on this strategy, tracklets sequentially grow with online-provided detections, and fragmented tracklets are linked up with others without any iterative and expensive association steps. For more reliable association between tracklets and detections, we also propose a deep appearance learning method to learn a discriminative appearance model from large training datasets, since the conventional appearance learning methods do not provide rich representation that can distinguish multiple objects with large appearance variations. In addition, we combine online transfer learning for improving appearance discriminability by adapting the pre-trained deep model during online tracking. Experiments with challenging public datasets show distinct performance improvement over other state-of-the-arts batch and online tracking methods, and prove the effect and usefulness of the proposed methods for online multi-object tracking.

  3. Intracranial self-stimulation also facilitates learning in a visual discrimination task in the Morris water maze in rats.

    Science.gov (United States)

    García-Brito, Soleil; Morgado-Bernal, Ignacio; Biosca-Simon, Neus; Segura-Torres, Pilar

    2017-01-15

    Intracranial self-Stimulation (ICSS) of the medial forebrain bundle is a treatment capable of consistently facilitating acquisition of learning and memory in a wide array of experimental paradigms in rats. However, the evidence supporting this effect on implicit memory comes mainly from classical conditioning and avoidance tasks. The present work aims to determine whether ICSS would also improve the performance of rats in another type of implicit task such as cued simultaneous visual discrimination in the Morris Water Maze. The ICSS treatment was administered immediately after each of the five acquisition sessions and its effects on retention and reversal were evaluated 72h later. Results showed that ICSS subjects committed fewer errors than Sham subjects and adopted more accurate trajectories during the acquisition of the task. This improvement was maintained until the probe test at 72h. However, ICSS animals experienced more difficulties than the Sham group during the reversal of the same learning, reflecting an impairment in cognitive flexibility. We conclude that post-training ICSS could also be an effective treatment for improving implicit visual discrimination learning and memory. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Early postnatal x-irradiation of the hippocampus and discrimination learning in adult rats

    International Nuclear Information System (INIS)

    Gazzara, R.A.; Altman, J.

    1981-01-01

    Rats with X-irradiation-produced degranulation of the hippocampal dentate gyrus were trained in the acquisition and reversal of simultaneous visual and tactile discriminations in a T-maze. These experiments employed the same treatment, apparatus, and procedure but varied in task difficulty. In the brightness and roughness discriminations, the irradiated rats were not handicapped in acquiring or reversing discriminations of low or low-moderate task difficulty. However, these rats were handicapped in acquiring and reversing discriminations of moderate and high task difficulty. In a Black/White discrimination, in which the stimuli were restricted to the goal-arm walls, the irradiated rats were handicapped in the acquisition (low task difficulty) and reversal (moderate task difficulty) phases of the task. These results suggest that the irradiated rats were not handicapped when the noticeability of the stimuli was high, irrespective of modality used, but were handicapped when the noticeability of the stimuli was low. In addition, these results are consistent with the hypothesis that rats with hippocampal damage are inattentive due to hyperactivity

  5. Effects of early postnatal X-irradiation of the hippocampus on discrimination learning in adult rats

    International Nuclear Information System (INIS)

    Gazzara, R.A.

    1980-01-01

    Rats with x-irradiation-produced degranulation of the hippocampal dentate gyrus were trained in the acquisition and reversal of simultaneous visual and tactile discriminations in a T-maze. These experiments employed the same treatment, apparatus, and procedure, but varied in task difficulty. In the brightness and roughness discriminations, the irradiated rats were not handicapped in acquiring or reversing discriminations of low or low-moderate task-difficulty. However, these rats were handicapped in acquiring and reversing discriminations of moderate and high task-difficulty. In a Black/White discrimination, in which the stimuli were restricted to the goal-arm walls, the irradiated rats were handicapped in the acquisition (low task-difficulty) and reversal (moderate task-difficulty) phases of the task. These results suggest that the irradiated rats were not handicapped when the noticeability of the stimuli was high, irrespective of modality used, but were handicapped when the noticeability of the stimuli was low. In addition, these results are consistent with the hypothesis that hippocampal-damaged rats are inattentive due to hyperactivity

  6. Observations on auditory learning in amplitude- and frequency-modulation rate discrimination

    DEFF Research Database (Denmark)

    Hoffmann, Pablo F.

    2010-01-01

    Because amplitude- and frequency-modulated sounds can be the basis for the synthesis of many complex sounds, they can be good candidates in the design of training systems aiming at improving the acquisition of perceptual skills that can benefit from information provided via the auditory channel......-training, training, a post-training stages. During training, listeners were divided into two groups; one group trained on amplitude-modulation rate discrimination and the other group trained on frequency-modulation rate discrimination. Results will be discussed in terms of their implications for training...

  7. Very deep learning for ship discrimination in synthetic aperture radar imagery

    CSIR Research Space (South Africa)

    Schwegmann, Colin P

    2016-07-01

    Full Text Available using machine learning. Newer, advanced deep learning techniques offer a unique solution but traditionally require a large dataset to train effectively. Highway Networks allow for very deep networks that can be trained using the smaller datasets typical...

  8. An unsupervised learning algorithm: application to the discrimination of seismic events and quarry blasts in the vicinity of Istanbul

    Directory of Open Access Journals (Sweden)

    H. S. Kuyuk

    2011-01-01

    Full Text Available The results of the application of an unsupervised learning (neural network approach comprising a Self Organizing Map (SOM, to distinguish micro-earthquakes from quarry blasts in the vicinity of Istanbul, Turkey, are presented and discussed. The SOM is constructed as a neural classifier and complementary reliability estimator to distinguish seismic events, and was employed for varying map sizes. Input parameters consisting of frequency and time domain data (complexity, spectral ratio, S/P wave amplitude peak ratio and origin time of events extracted from the vertical components of digital seismograms were estimated as discriminants for 179 (1.8 < Md < 3.0 local events. The results show that complexity and amplitude peak ratio parameters of the observed velocity seismogram may suffice for a reliable discrimination, while origin time and spectral ratio were found to be fuzzy and misleading classifiers for this problem. The SOM discussed here achieved a discrimination reliability that could be employed routinely in observatory practice; however, about 6% of all events were classified as ambiguous cases. This approach was developed independently for this particular classification, but it could be applied to different earthquake regions.

  9. A Comparative Study of Discrimination in Education: The Learning Environment and Behaviours of Students and Teachers in Iran

    Directory of Open Access Journals (Sweden)

    Mozhgan Ghaffarzadeh

    2016-09-01

    Full Text Available It is the learners' right to get an education free from discrimination. Discrimination in education ranges from gender to race, age, social class, financial status, and other characteristics. In this study the focus is on discrimination in education in regard to social class and financial status. The paper describes observations of the school building layout and corresponding activities and behaviours in language education classes. The researcher observed 10 English language classes from different districts during 10 years from 2004 through 2014 and took notes on the activities and behaviours provided in the classroom to identify whether there was any correspondence with educational behaviours. The investigation in this study concluded that the language classes of most of the public (state schools and some semi-private schools included a curriculum based on translation and memorization teaching methods. In these schools, learners exhibited stress and inattention that disturbed their learning. In these classes learners were threatened by laughing or rough criticizing by the teachers. The observation results were analyzed to make comparisons between schools and inform the level of equality in different schools.

  10. Lessons learned in the execution of advanced x-ray material discrimination (Conference Presentation)

    Science.gov (United States)

    Young, Sharene

    2017-05-01

    Advanced X-ray Material Discrimination (AXMD) or BAA 13-05 was a broad agency announcement which was initiated in order to develop solutions to the following problem. The emergence of improvised explosive threats and their use by terrorists has placed many challenges on the aviation security screening layers. EDS and AT X-ray equipment have been presented with considerable challenges in developing a broad detection capability for improvised explosive threats during security screening of checked bags and carry-on items. Technologies are needed that increase the measurement or mathematical discrimination between improvised explosive threats and stream-of-commerce clutter in checked baggage and carry-on items. Conventional EDS utilizes two basic discriminating signatures: effective atomic number and density of screened objects. R and D is needed to identify additional discriminating signatures between improvised explosive threats and stream-of commerce clutter to improve detection capability with reduced false alarm rates. DHS S and T EXD along with stakeholders at the TSA, TSL, and the UK Home Office have been successful in funding efforts to address and potentially provide operational solutions which can be deployed as part of the Next Generation of X-ray Technologies.

  11. Statistics that learn: can logistic discriminant analysis improve diagnosis in brain SPECT?

    International Nuclear Information System (INIS)

    Behin-Ain, S.; Barnden, L.; Kwiatek, R.; Del Fante, P.; Casse, R.; Burnet, R.; Chew, G.; Kitchener, M.; Boundy, K.; Unger, S.

    2002-01-01

    Full text: Logistic discriminant analysis (LDA) is a statistical technique capable of discriminating individuals within a diseased group against normals. It also enables classification of various diseases within a group of patients. This technique provides a quantitative, automated and non-subjective clinical diagnostic tool. Based on a population known to have the disease and a normal control group, an algorithm was developed and trained to identify regions in the human brain responsible for the disease in question. The algorithm outputs a statistical map representing diseased or normal probability on a voxel or cluster basis from which an index is generated for each subject. The algorithm also generates a set of coefficients which is used to generate an index for the purpose of classification of new subjects. The results are comparable and complement those of Statistical Parametric Mapping (SPM) which employs a more common linear discriminant technique. The results are presented for brain SPECT studies of two diseases: chronic fatigue syndrome (CFS) and fibromyalgia (FM). A 100% specificity and 94% sensitivity is achieved for the CFS study (similar to SPM results) and for the FM study 82% specificity and 94% sensitivity is achieved with corresponding SPM results showing 90% specificity and 82% sensitivity. The results encourages application of LDA for discrimination of new single subjects as well as of diseased and normal groups. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  12. Development and assessment of a lysophospholipid-based deep learning model to discriminate geographical origins of white rice.

    Science.gov (United States)

    Long, Nguyen Phuoc; Lim, Dong Kyu; Mo, Changyeun; Kim, Giyoung; Kwon, Sung Won

    2017-08-17

    Geographical origin determination of white rice has become the major issue of food industry. However, there is still lack of a high-throughput method for rapidly and reproducibly differentiating the geographical origins of commercial white rice. In this study, we developed a method that employed lipidomics and deep learning to discriminate white rice from Korea to China. A total of 126 white rice of 30 cultivars from different regions were utilized for the method development and validation. By using direct infusion-mass spectrometry-based targeted lipidomics, 17 lysoglycerophospholipids were simultaneously characterized within minutes per sample. Unsupervised data exploration showed a noticeable overlap of white rice between two countries. In addition, lysophosphatidylcholines (lysoPCs) were prominent in white rice from Korea while lysophosphatidylethanolamines (lysoPEs) were enriched in white rice from China. A deep learning prediction model was built using 2014 white rice and validated using two different batches of 2015 white rice. The model accurately discriminated white rice from two countries. Among 10 selected predictors, lysoPC(18:2), lysoPC(14:0), and lysoPE(16:0) were the three most important features. Random forest and gradient boosting machine models also worked well in this circumstance. In conclusion, this study provides an architecture for high-throughput classification of white rice from different geographical origins.

  13. Discrimination of plant root zone water status in greenhouse production based on phenotyping and machine learning techniques.

    Science.gov (United States)

    Guo, Doudou; Juan, Jiaxiang; Chang, Liying; Zhang, Jingjin; Huang, Danfeng

    2017-08-15

    Plant-based sensing on water stress can provide sensitive and direct reference for precision irrigation system in greenhouse. However, plant information acquisition, interpretation, and systematical application remain insufficient. This study developed a discrimination method for plant root zone water status in greenhouse by integrating phenotyping and machine learning techniques. Pakchoi plants were used and treated by three root zone moisture levels, 40%, 60%, and 80% relative water content. Three classification models, Random Forest (RF), Neural Network (NN), and Support Vector Machine (SVM) were developed and validated in different scenarios with overall accuracy over 90% for all. SVM model had the highest value, but it required the longest training time. All models had accuracy over 85% in all scenarios, and more stable performance was observed in RF model. Simplified SVM model developed by the top five most contributing traits had the largest accuracy reduction as 29.5%, while simplified RF and NN model still maintained approximately 80%. For real case application, factors such as operation cost, precision requirement, and system reaction time should be synthetically considered in model selection. Our work shows it is promising to discriminate plant root zone water status by implementing phenotyping and machine learning techniques for precision irrigation management.

  14. SAR Target Recognition via Supervised Discriminative Dictionary Learning and Sparse Representation of the SAR-HOG Feature

    Directory of Open Access Journals (Sweden)

    Shengli Song

    2016-08-01

    Full Text Available Automatic target recognition (ATR in synthetic aperture radar (SAR images plays an important role in both national defense and civil applications. Although many methods have been proposed, SAR ATR is still very challenging due to the complex application environment. Feature extraction and classification are key points in SAR ATR. In this paper, we first design a novel feature, which is a histogram of oriented gradients (HOG-like feature for SAR ATR (called SAR-HOG. Then, we propose a supervised discriminative dictionary learning (SDDL method to learn a discriminative dictionary for SAR ATR and propose a strategy to simplify the optimization problem. Finally, we propose a SAR ATR classifier based on SDDL and sparse representation (called SDDLSR, in which both the reconstruction error and the classification error are considered. Extensive experiments are performed on the MSTAR database under standard operating conditions and extended operating conditions. The experimental results show that SAR-HOG can reliably capture the structures of targets in SAR images, and SDDL can further capture subtle differences among the different classes. By virtue of the SAR-HOG feature and SDDLSR, the proposed method achieves the state-of-the-art performance on MSTAR database. Especially for the extended operating conditions (EOC scenario “Training 17 ∘ —Testing 45 ∘ ”, the proposed method improves remarkably with respect to the previous works.

  15. Age and education adjusted normative data and discriminative validity for Rey's Auditory Verbal Learning Test in the elderly Greek population.

    Science.gov (United States)

    Messinis, Lambros; Nasios, Grigorios; Mougias, Antonios; Politis, Antonis; Zampakis, Petros; Tsiamaki, Eirini; Malefaki, Sonia; Gourzis, Phillipos; Papathanasopoulos, Panagiotis

    2016-01-01

    Rey's Auditory Verbal Learning Test (RAVLT) is a widely used neuropsychological test to assess episodic memory. In the present study we sought to establish normative and discriminative validity data for the RAVLT in the elderly population using previously adapted learning lists for the Greek adult population. We administered the test to 258 cognitively healthy elderly participants, aged 60-89 years, and two patient groups (192 with amnestic mild cognitive impairment, aMCI, and 65 with Alzheimer's disease, AD). From the statistical analyses, we found that age and education contributed significantly to most trials of the RAVLT, whereas the influence of gender was not significant. Younger elderly participants with higher education outperformed the older elderly with lower education levels. Moreover, both clinical groups performed significantly worse on most RAVLT trials and composite measures than matched cognitively healthy controls. Furthermore, the AD group performed more poorly than the aMCI group on most RAVLT variables. Receiver operating characteristic (ROC) analysis was used to examine the utility of the RAVLT trials to discriminate cognitively healthy controls from aMCI and AD patients. Area under the curve (AUC), an index of effect size, showed that most of the RAVLT measures (individual and composite) included in this study adequately differentiated between the performance of healthy elders and aMCI/AD patients. We also provide cutoff scores in discriminating cognitively healthy controls from aMCI and AD patients, based on the sensitivity and specificity of the prescribed scores. Moreover, we present age- and education-specific normative data for individual and composite scores for the Greek adapted RAVLT in elderly subjects aged between 60 and 89 years for use in clinical and research settings.

  16. Best of Both Worlds: Transferring Knowledge from Discriminative Learning to a Generative Visual Dialog Model

    OpenAIRE

    Lu, Jiasen; Kannan, Anitha; Yang, Jianwei; Parikh, Devi; Batra, Dhruv

    2017-01-01

    We present a novel training framework for neural sequence models, particularly for grounded dialog generation. The standard training paradigm for these models is maximum likelihood estimation (MLE), or minimizing the cross-entropy of the human responses. Across a variety of domains, a recurring problem with MLE trained generative neural dialog models (G) is that they tend to produce 'safe' and generic responses ("I don't know", "I can't tell"). In contrast, discriminative dialog models (D) th...

  17. Stress facilitates late reversal learning using a touchscreen-based visual discrimination procedure in male Long Evans rats.

    Science.gov (United States)

    Bryce, Courtney A; Howland, John G

    2015-02-01

    The stress response is essential to the survival of all species as it maintains internal equilibrium and allows organisms to respond to threats in the environment. Most stress research has focused on the detrimental impacts of stress on cognition and behavior. Reversal learning, which requires a change in response strategy based on one dimension of the stimuli, is one type of behavioral flexibility that is facilitated following some brief stress procedures. The current study investigated a potential mechanism underlying this facilitation by blocking glucocorticoid receptors (GRs) during stress. Thirty-seven male Long Evans rats learned to discriminate between two images on a touchscreen, one of which was rewarded. Once a criterion was reached, rats received stress (30 min of restraint stress or no stress) and drug (GR antagonist RU38486 or vehicle) administration prior to each of the first 3 days of reversal learning. We expected that stress would facilitate reversal learning and RU38486 (10 mg/kg) would prevent this facilitation in both early (50% correct in one session) stages of reversal learning. Results showed that stressed rats performed better than unstressed rats (fewer days for late reversal, fewer correction trials, and fewer errors) in the late but not early stage of reversal learning. RU38486 did not block the facilitation of RL by stress, although it dramatically increased response, but not reward, latencies. These results confirm the facilitation of late reversal by stress in a touchscreen-based operant task in rats and further our understanding of how stress affects higher level cognitive functioning and behavior. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Statistical Discriminability Estimation for Pattern Classification Based on Neural Incremental Attribute Learning

    DEFF Research Database (Denmark)

    Wang, Ting; Guan, Sheng-Uei; Puthusserypady, Sadasivan

    2014-01-01

    Feature ordering is a significant data preprocessing method in Incremental Attribute Learning (IAL), a novel machine learning approach which gradually trains features according to a given order. Previous research has shown that, similar to feature selection, feature ordering is also important based...

  19. Discrimination of Brazilian propolis according to the seasoning using chemometrics and machine learning based on UV-Vis scanning data.

    Science.gov (United States)

    Tomazzoli, Maíra Maciel; Pai Neto, Remi Dal; Moresco, Rodolfo; Westphal, Larissa; Zeggio, Amélia Regina Somensi; Specht, Leandro; Costa, Christopher; Rocha, Miguel; Maraschin, Marcelo

    2015-10-21

    Propolis is a chemically complex biomass produced by honeybees (Apis mellifera) from plant resins added of salivary enzymes, beeswax, and pollen. The biological activities described for propolis were also identified for donor plant's resin, but a big challenge for the standardization of the chemical composition and biological effects of propolis remains on a better understanding of the influence of seasonality on the chemical constituents of that raw material. Since propolis quality depends, among other variables, on the local flora which is strongly influenced by (a)biotic factors over the seasons, to unravel the harvest season effect on the propolis' chemical profile is an issue of recognized importance. For that, fast, cheap, and robust analytical techniques seem to be the best choice for large scale quality control processes in the most demanding markets, e.g., human health applications. For that, UV-Visible (UV-Vis) scanning spectrophotometry of hydroalcoholic extracts (HE) of seventy-three propolis samples, collected over the seasons in 2014 (summer, spring, autumn, and winter) and 2015 (summer and autumn) in Southern Brazil was adopted. Further machine learning and chemometrics techniques were applied to the UV-Vis dataset aiming to gain insights as to the seasonality effect on the claimed chemical heterogeneity of propolis samples determined by changes in the flora of the geographic region under study. Descriptive and classification models were built following a chemometric approach, i.e. principal component analysis (PCA) and hierarchical clustering analysis (HCA) supported by scripts written in the R language. The UV-Vis profiles associated with chemometric analysis allowed identifying a typical pattern in propolis samples collected in the summer. Importantly, the discrimination based on PCA could be improved by using the dataset of the fingerprint region of phenolic compounds (λ = 280-400ηm), suggesting that besides the biological activities of those

  20. Discrimination of Brazilian propolis according to the seasoning using chemometrics and machine learning based on UV-Vis scanning data.

    Science.gov (United States)

    Tomazzoli, Maíra M; Pai Neto, Remi D; Moresco, Rodolfo; Westphal, Larissa; Zeggio, Amelia R S; Specht, Leandro; Costa, Christopher; Rocha, Miguel; Maraschin, Marcelo

    2015-12-01

    Propolis is a chemically complex biomass produced by honeybees (Apis mellifera) from plant resins added of salivary enzymes, beeswax, and pollen. The biological activities described for propolis were also identified for donor plant's resin, but a big challenge for the standardization of the chemical composition and biological effects of propolis remains on a better understanding of the influence of seasonality on the chemical constituents of that raw material. Since propolis quality depends, among other variables, on the local flora which is strongly influenced by (a)biotic factors over the seasons, to unravel the harvest season effect on the propolis chemical profile is an issue of recognized importance. For that, fast, cheap, and robust analytical techniques seem to be the best choice for large scale quality control processes in the most demanding markets, e.g., human health applications. For that, UV-Visible (UV-Vis) scanning spectrophotometry of hydroalcoholic extracts (HE) of seventy-three propolis samples, collected over the seasons in 2014 (summer, spring, autumn, and winter) and 2015 (summer and autumn) in Southern Brazil was adopted. Further machine learning and chemometrics techniques were applied to the UV-Vis dataset aiming to gain insights as to the seasonality effect on the claimed chemical heterogeneity of propolis samples determined by changes in the flora of the geographic region under study. Descriptive and classification models were built following a chemometric approach, i.e. principal component analysis (PCA) and hierarchical clustering analysis (HCA) supported by scripts written in the R language. The UV-Vis profiles associated with chemometric analysis allowed identifying a typical pattern in propolis samples collected in the summer. Importantly, the discrimination based on PCA could be improved by using the dataset of the fingerprint region of phenolic compounds ( λ= 280-400 ηm), suggesting that besides the biological activities of those

  1. Discrimination of Brazilian propolis according to the seasoning using chemometrics and machine learning based on UV-Vis scanning data

    Directory of Open Access Journals (Sweden)

    Tomazzoli Maíra M.

    2015-12-01

    Full Text Available Propolis is a chemically complex biomass produced by honeybees (Apis mellifera from plant resins added of salivary enzymes, beeswax, and pollen. The biological activities described for propolis were also identified for donor plant’s resin, but a big challenge for the standardization of the chemical composition and biological effects of propolis remains on a better understanding of the influence of seasonality on the chemical constituents of that raw material. Since propolis quality depends, among other variables, on the local flora which is strongly influenced by (abiotic factors over the seasons, to unravel the harvest season effect on the propolis chemical profile is an issue of recognized importance. For that, fast, cheap, and robust analytical techniques seem to be the best choice for large scale quality control processes in the most demanding markets, e.g., human health applications. For that, UV-Visible (UV-Vis scanning spectrophotometry of hydroalcoholic extracts (HE of seventy-three propolis samples, collected over the seasons in 2014 (summer, spring, autumn, and winter and 2015 (summer and autumn in Southern Brazil was adopted. Further machine learning and chemometrics techniques were applied to the UV-Vis dataset aiming to gain insights as to the seasonality effect on the claimed chemical heterogeneity of propolis samples determined by changes in the flora of the geographic region under study. Descriptive and classification models were built following a chemometric approach, i.e. principal component analysis (PCA and hierarchical clustering analysis (HCA supported by scripts written in the R language. The UV-Vis profiles associated with chemometric analysis allowed identifying a typical pattern in propolis samples collected in the summer. Importantly, the discrimination based on PCA could be improved by using the dataset of the fingerprint region of phenolic compounds ( λ= 280-400 ηm, suggesting that besides the biological

  2. Improving dense conditional random field for retinal vessel segmentation by discriminative feature learning and thin-vessel enhancement.

    Science.gov (United States)

    Zhou, Lei; Yu, Qi; Xu, Xun; Gu, Yun; Yang, Jie

    2017-09-01

    As retinal vessels in color fundus images are thin and elongated structures, standard pairwise based random fields, which always suffer the "shrinking bias" problem, are not competent for such segmentation task. Recently, a dense conditional random field (CRF) model has been successfully used in retinal vessel segmentation. Its corresponding energy function is formulated as a linear combination of several unary features and a pairwise term. However, the hand-crafted unary features can be suboptimal in terms of linear models. Here we propose to learn discriminative unary features and enhance thin vessels for pairwise potentials to further improve the segmentation performance. Our proposed method comprises four main steps: firstly, image preprocessing is applied to eliminate the strong edges around the field of view (FOV) and normalize the luminosity and contrast inside FOV; secondly, a convolutional neural network (CNN) is properly trained to generate discriminative features for linear models; thirdly, a combo of filters are applied to enhance thin vessels, reducing the intensity difference between thin and wide vessels; fourthly, by taking the discriminative features for unary potentials and the thin-vessel enhanced image for pairwise potentials, we adopt the dense CRF model to achieve the final retinal vessel segmentation. The segmentation performance is evaluated on four public datasets (i.e. DRIVE, STARE, CHASEDB1 and HRF). Experimental results show that our proposed method improves the performance of the dense CRF model and outperforms other methods when evaluated in terms of F1-score, Matthews correlation coefficient (MCC) and G-mean, three effective metrics for the evaluation of imbalanced binary classification. Specifically, the F1-score, MCC and G-mean are 0.7942, 0.7656, 0.8835 for the DRIVE dataset respectively; 0.8017, 0.7830, 0.8859 for STARE respectively; 0.7644, 0.7398, 0.8579 for CHASEDB1 respectively; and 0.7627, 0.7402, 0.8812 for HRF respectively

  3. Trial-dependent psychometric functions accounting for perceptual learning in 2-AFC discrimination tasks.

    Science.gov (United States)

    Kattner, Florian; Cochrane, Aaron; Green, C Shawn

    2017-09-01

    The majority of theoretical models of learning consider learning to be a continuous function of experience. However, most perceptual learning studies use thresholds estimated by fitting psychometric functions to independent blocks, sometimes then fitting a parametric function to these block-wise estimated thresholds. Critically, such approaches tend to violate the basic principle that learning is continuous through time (e.g., by aggregating trials into large "blocks" for analysis that each assume stationarity, then fitting learning functions to these aggregated blocks). To address this discrepancy between base theory and analysis practice, here we instead propose fitting a parametric function to thresholds from each individual trial. In particular, we implemented a dynamic psychometric function whose parameters were allowed to change continuously with each trial, thus parameterizing nonstationarity. We fit the resulting continuous time parametric model to data from two different perceptual learning tasks. In nearly every case, the quality of the fits derived from the continuous time parametric model outperformed the fits derived from a nonparametric approach wherein separate psychometric functions were fit to blocks of trials. Because such a continuous trial-dependent model of perceptual learning also offers a number of additional advantages (e.g., the ability to extrapolate beyond the observed data; the ability to estimate performance on individual critical trials), we suggest that this technique would be a useful addition to each psychophysicist's analysis toolkit.

  4. Perceptual learning of motion direction discrimination with suppressed and unsuppressed MT in humans: an fMRI study.

    Directory of Open Access Journals (Sweden)

    Benjamin Thompson

    Full Text Available The middle temporal area of the extrastriate visual cortex (area MT is integral to motion perception and is thought to play a key role in the perceptual learning of motion tasks. We have previously found, however, that perceptual learning of a motion discrimination task is possible even when the training stimulus contains locally balanced, motion opponent signals that putatively suppress the response of MT. Assuming at least partial suppression of MT, possible explanations for this learning are that 1 training made MT more responsive by reducing motion opponency, 2 MT remained suppressed and alternative visual areas such as V1 enabled learning and/or 3 suppression of MT increased with training, possibly to reduce noise. Here we used fMRI to test these possibilities. We first confirmed that the motion opponent stimulus did indeed suppress the BOLD response within hMT+ compared to an almost identical stimulus without locally balanced motion signals. We then trained participants on motion opponent or non-opponent stimuli. Training with the motion opponent stimulus reduced the BOLD response within hMT+ and greater reductions in BOLD response were correlated with greater amounts of learning. The opposite relationship between BOLD and behaviour was found at V1 for the group trained on the motion-opponent stimulus and at both V1 and hMT+ for the group trained on the non-opponent motion stimulus. As the average response of many cells within MT to motion opponent stimuli is the same as their response to non-directional flickering noise, the reduced activation of hMT+ after training may reflect noise reduction.

  5. Fast learning of simple perceptual discriminations reduces brain activation in working memory and in high-level auditory regions.

    Science.gov (United States)

    Daikhin, Luba; Ahissar, Merav

    2015-07-01

    Introducing simple stimulus regularities facilitates learning of both simple and complex tasks. This facilitation may reflect an implicit change in the strategies used to solve the task when successful predictions regarding incoming stimuli can be formed. We studied the modifications in brain activity associated with fast perceptual learning based on regularity detection. We administered a two-tone frequency discrimination task and measured brain activation (fMRI) under two conditions: with and without a repeated reference tone. Although participants could not explicitly tell the difference between these two conditions, the introduced regularity affected both performance and the pattern of brain activation. The "No-Reference" condition induced a larger activation in frontoparietal areas known to be part of the working memory network. However, only the condition with a reference showed fast learning, which was accompanied by a reduction of activity in two regions: the left intraparietal area, involved in stimulus retention, and the posterior superior-temporal area, involved in representing auditory regularities. We propose that this joint reduction reflects a reduction in the need for online storage of the compared tones. We further suggest that this change reflects an implicit strategic shift "backwards" from reliance mainly on working memory networks in the "No-Reference" condition to increased reliance on detected regularities stored in high-level auditory networks.

  6. Externalizing psychopathology and behavioral disinhibition: working memory mediates signal discriminability and reinforcement moderates response bias in approach-avoidance learning.

    Science.gov (United States)

    Endres, Michael J; Rickert, Martin E; Bogg, Tim; Lucas, Jesolyn; Finn, Peter R

    2011-05-01

    Research has suggested that reduced working memory capacity plays a key role in disinhibited patterns of behavior associated with externalizing psychopathology. In this study, participants (N = 365) completed 2 versions of a go/no-go mixed-incentive learning task that differed in the relative frequency of monetary rewards and punishments for correct and incorrect active-approach responses, respectively. Using separate structural equation models for conventional (hit and false alarm rates) and signal detection theory (signal discriminability and response bias) performance indices, distinct roles for working memory capacity and changes in payoff structure were found. Specifically, results showed that (a) working memory capacity mediated the effects of externalizing psychopathology on false alarms and discriminability of go versus no-go signals; (b) these effects were not moderated by the relative frequency of monetary rewards and punishments; (c) the relative frequency of monetary rewards and punishments moderated the effects of externalizing psychopathology on hits and response bias for go versus no-go responses; and (d) these effects were not mediated by working memory capacity. The findings implicate distinct roles for reduced working memory capacity and poorly modulated active approach and passive avoidance in the link between externalizing psychopathology and behavioral disinhibition.

  7. Auditory discrimination predicts linguistic outcome in Italian infants with and without familial risk for language learning impairment.

    Science.gov (United States)

    Cantiani, Chiara; Riva, Valentina; Piazza, Caterina; Bettoni, Roberta; Molteni, Massimo; Choudhury, Naseem; Marino, Cecilia; Benasich, April A

    2016-08-01

    Infants' ability to discriminate between auditory stimuli presented in rapid succession and differing in fundamental frequency (Rapid Auditory Processing [RAP] abilities) has been shown to be anomalous in infants at familial risk for Language Learning Impairment (LLI) and to predict later language outcomes. This study represents the first attempt to investigate RAP in Italian infants at risk for LLI (FH+), examining two critical acoustic features: frequency and duration, both embedded in a rapidly-presented acoustic environment. RAP skills of 24 FH+ and 32 control (FH-) Italian 6-month-old infants were characterized via EEG/ERP using a multi-feature oddball paradigm. Outcome measures of expressive vocabulary were collected at 20 months. Group differences favoring FH- infants were identified: in FH+ infants, the latency of the N2* peak was delayed and the mean amplitude of the positive mismatch response was reduced, primarily for frequency discrimination and within the right hemisphere. Moreover, both EEG measures were correlated with language scores at 20 months. Results indicate that RAP abilities are atypical in Italian infants with a first-degree relative affected by LLI and that this impacts later linguistic skills. These findings provide a compelling cross-linguistic comparison with previous research on American infants, supporting the biological unity hypothesis of LLI. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Changes in PKCγ lmmunoreactivity in Mouse Hippocampus Induced by Spatial Discrimination Learning

    OpenAIRE

    Zee, E.A. van der; Compaan, J.C.; Boer, M. de; Luiten, P.G.M.

    1992-01-01

    In the present study, we examined changes in immunoreactivity (ir) for the γ-isoform of protein kinase C (PKCγ) in mouse hippocampus in relation to spatial memory processes employing the monoclonal antibody 36G9 raised against purified PKCγ. Learning and memory were assessed by performance in a free-choice spatial pattern paradigm in a hole board in which the animals learned the pattern of 4 baited holes out of 16 holes. Adult male house mice were used, divided in four groups. Three control g...

  9. Muscarinic receptor binding increases in anterior thalamus and cingulate cortex during discriminative avoidance learning

    International Nuclear Information System (INIS)

    Vogt, B.A.; Gabriel, M.; Vogt, L.J.; Poremba, A.; Jensen, E.L.; Kubota, Y.; Kang, E.

    1991-01-01

    Training-induced neuronal activity develops in the mammalian limbic system during discriminative avoidance conditioning. This study explores behaviorally relevant changes in muscarinic ACh receptor binding in 52 rabbits that were trained to one of five stages of conditioned response acquisition. Sixteen naive and 10 animals yoked to criterion performance served as control cases. Upon reaching a particular stage of training, the brains were removed and autoradiographically assayed for 3H-oxotremorine-M binding with 50 nM pirenzepine (OxO-M/PZ) or for 3H-pirenzepine binding in nine limbic thalamic nuclei and cingulate cortex. Specific OxO-M/PZ binding increased in the parvocellular division of the anterodorsal nucleus early in training when the animals were first exposed to pairing of the conditional and unconditional stimuli. Elevated binding in this nucleus was maintained throughout subsequent training. In the parvocellular division of the anteroventral nucleus (AVp), OxO-M/PZ binding progressively increased throughout training, reached a peak at the criterion stage of performance, and returned to control values during extinction sessions. Peak OxO-M/PZ binding in AVp was significantly elevated over that for cases yoked to criterion performance. In the magnocellular division of the anteroventral nucleus (AVm), OxO-M/PZ binding was elevated only during criterion performance of the task, and it was unaltered in any other limbic thalamic nuclei. Specific OxO-M/PZ binding was also elevated in most layers in rostral area 29c when subjects first performed a significant behavioral discrimination. Training-induced alterations in OxO-M/PZ binding in AVp and layer Ia of area 29c were similar and highly correlated

  10. Different Parameters Support Generalization and Discrimination Learning in "Drosophila" at the Flight Simulator

    Science.gov (United States)

    Brembs, Bjorn; de Ibarra, Natalie Hempel

    2006-01-01

    We have used a genetically tractable model system, the fruit fly "Drosophila melanogaster" to study the interdependence between sensory processing and associative processing on learning performance. We investigated the influence of variations in the physical and predictive properties of color stimuli in several different operant-conditioning…

  11. Changes in PKCγ lmmunoreactivity in Mouse Hippocampus Induced by Spatial Discrimination Learning

    NARCIS (Netherlands)

    Zee, E.A. van der; Compaan, J.C.; Boer, M. de; Luiten, P.G.M.

    1992-01-01

    In the present study, we examined changes in immunoreactivity (ir) for the γ-isoform of protein kinase C (PKCγ) in mouse hippocampus in relation to spatial memory processes employing the monoclonal antibody 36G9 raised against purified PKCγ. Learning and memory were assessed by performance in a

  12. CHANGES IN PKC-GAMMA IMMUNOREACTIVITY IN MOUSE HIPPOCAMPUS INDUCED BY SPATIAL DISCRIMINATION-LEARNING

    NARCIS (Netherlands)

    VANDERZEE, EA; COMPAAN, JC; DEBOER, M; LUITEN, PGM

    1992-01-01

    In the present study, we examined changes in immunoreactivity (ir) for the gamma-isoform of protein kinase C (PKCgamma) in mouse hippocampus in relation to spatial memory processes employing the monoclonal antibody 36G9 raised against purified PKCgamma. Learning and memory were assessed by

  13. Measuring Discrimination- and Reversal Learning in Mouse Models within 4 Days and without Prior Food Deprivation

    Science.gov (United States)

    Remmelink, Esther; Smit, August B.; Verhage, Matthijs; Loos, Maarten

    2016-01-01

    Many neurological and psychiatric disorders are characterized by deficits in cognitive flexibility. Modeling cognitive flexibility in mice enables the investigation of mechanisms underlying these deficits. The majority of currently available behavioral tests targeting this cognitive domain are reversal learning tasks that require scheduled food…

  14. Combining Generative and Discriminative Representation Learning for Lung CT Analysis With Convolutional Restricted Boltzmann Machines

    NARCIS (Netherlands)

    G. van Tulder (Gijs); M. de Bruijne (Marleen)

    2016-01-01

    textabstractThe choice of features greatly influences the performance of a tissue classification system. Despite this, many systems are built with standard, predefined filter banks that are not optimized for that particular application. Representation learning methods such as restricted Boltzmann

  15. Fos Protein Expression in Olfactory-Related Brain Areas after Learning and after Reactivation of a Slowly Acquired Olfactory Discrimination Task in the Rat

    Science.gov (United States)

    Roullet, Florence; Lienard, Fabienne; Datiche, Frederique; Cattarelli, Martine

    2005-01-01

    Fos protein immunodetection was used to investigate the neuronal activation elicited in some olfactory-related areas after either learning of an olfactory discrimination task or its reactivation 10 d later. Trained rats (T) progressively acquired the association between one odor of a pair and water-reward in a four-arm maze. Two groups of…

  16. Unpredictable chronic mild stress differentially impairs social and contextual discrimination learning in two inbred mouse strains.

    Directory of Open Access Journals (Sweden)

    Michiel van Boxelaere

    Full Text Available Alterations in the social and cognitive domain are considered important indicators for increased disability in many stress-related disorders. Similar impairments have been observed in rodents chronically exposed to stress, mimicking potential endophenotypes of stress-related psychopathologies such as major depression disorder (MDD, anxiety, conduct disorder, and posttraumatic stress disorder (PTSD. Data from numerous studies suggest that deficient plasticity mechanisms in hippocampus (HC and prefrontal cortex (PFC might underlie these social and cognitive deficits. Specifically, stress-induced deficiencies in neural plasticity have been associated with a hypodopaminergic state and reduced neural plasticity persistence. Here we assessed the effects of unpredictable chronic mild stress (UCMS on exploratory, social and cognitive behavior of females of two inbred mouse strains (C57BL/6J and DBA/2J that differ in their dopaminergic profile. Exposure to chronic stress resulted in impaired circadian rhythmicity, sociability and social cognition in both inbred strains, but differentially affected activity patterns and contextual discrimination performance. These stress-induced behavioral impairments were accompanied by reduced expression levels of brain derived neurotrophic factor (BDNF in the prefrontal cortex. The strain-specific cognitive impairment was coexistent with enhanced plasma corticosterone levels and reduced expression of genes related to dopamine signaling in hippocampus. These results underline the importance of assessing different strains with multiple test batteries to elucidate the neural and genetic basis of social and cognitive impairments related to chronic stress.

  17. Unpredictable chronic mild stress differentially impairs social and contextual discrimination learning in two inbred mouse strains.

    Science.gov (United States)

    van Boxelaere, Michiel; Clements, Jason; Callaerts, Patrick; D'Hooge, Rudi; Callaerts-Vegh, Zsuzsanna

    2017-01-01

    Alterations in the social and cognitive domain are considered important indicators for increased disability in many stress-related disorders. Similar impairments have been observed in rodents chronically exposed to stress, mimicking potential endophenotypes of stress-related psychopathologies such as major depression disorder (MDD), anxiety, conduct disorder, and posttraumatic stress disorder (PTSD). Data from numerous studies suggest that deficient plasticity mechanisms in hippocampus (HC) and prefrontal cortex (PFC) might underlie these social and cognitive deficits. Specifically, stress-induced deficiencies in neural plasticity have been associated with a hypodopaminergic state and reduced neural plasticity persistence. Here we assessed the effects of unpredictable chronic mild stress (UCMS) on exploratory, social and cognitive behavior of females of two inbred mouse strains (C57BL/6J and DBA/2J) that differ in their dopaminergic profile. Exposure to chronic stress resulted in impaired circadian rhythmicity, sociability and social cognition in both inbred strains, but differentially affected activity patterns and contextual discrimination performance. These stress-induced behavioral impairments were accompanied by reduced expression levels of brain derived neurotrophic factor (BDNF) in the prefrontal cortex. The strain-specific cognitive impairment was coexistent with enhanced plasma corticosterone levels and reduced expression of genes related to dopamine signaling in hippocampus. These results underline the importance of assessing different strains with multiple test batteries to elucidate the neural and genetic basis of social and cognitive impairments related to chronic stress.

  18. Awake, long-term intranasal insulin treatment does not affect object memory, odor discrimination, or reversal learning in mice.

    Science.gov (United States)

    Bell, Genevieve A; Fadool, Debra Ann

    2017-05-15

    Intranasal insulin delivery is currently being used in clinical trials to test for improvement in human memory and cognition, and in particular, for lessening memory loss attributed to neurodegenerative diseases. Studies have reported the effects of short-term intranasal insulin treatment on various behaviors, but less have examined long-term effects. The olfactory bulb contains the highest density of insulin receptors in conjunction with the highest level of insulin transport within the brain. Previous research from our laboratory has demonstrated that acute insulin intranasal delivery (IND) enhanced both short- and long-term memory as well as increased two-odor discrimination in a two-choice paradigm. Herein, we investigated the behavioral and physiological effects of chronic insulin IND. Adult, male C57BL6/J mice were intranasally treated with 5μg/μl of insulin twice daily for 30 and 60days. Metabolic assessment indicated no change in body weight, caloric intake, or energy expenditure following chronic insulin IND, but an increase in the frequency of meal bouts selectively in the dark cycle. Unlike acute insulin IND, which has been shown to cause enhanced performance in odor habituation/dishabituation and two-odor discrimination tasks in mice, chronic insulin IND did not enhance olfactometry-based odorant discrimination or olfactory reversal learning. In an object memory recognition task, insulin IND-treated mice did not perform differently than controls, regardless of task duration. Biochemical analyses of the olfactory bulb revealed a modest 1.3 fold increase in IR kinase phosphorylation but no significant increase in Kv1.3 phosphorylation. Substrate phosphorylation of IR kinase downstream effectors (MAPK/ERK and Akt signaling) proved to be highly variable. These data indicate that chronic administration of insulin IND in mice fails to enhance olfactory ability, object memory recognition, or a majority of systems physiology metabolic factors - as reported to

  19. A Comparative Study of Discrimination in Education: The Learning Environment and Behaviours of Students and Teachers in Iran

    Science.gov (United States)

    Ghaffarzadeh, Mozhgan

    2016-01-01

    It is the learners' right to get an education free from discrimination. Discrimination in education ranges from gender to race, age, social class, financial status, and other characteristics. In this study the focus is on discrimination in education in regard to social class and financial status. The paper describes observations of the school…

  20. Discriminative Transfer Subspace Learning via Low-Rank and Sparse Representation.

    Science.gov (United States)

    Xu, Yong; Fang, Xiaozhao; Wu, Jian; Li, Xuelong; Zhang, David

    2016-02-01

    In this paper, we address the problem of unsupervised domain transfer learning in which no labels are available in the target domain. We use a transformation matrix to transfer both the source and target data to a common subspace, where each target sample can be represented by a combination of source samples such that the samples from different domains can be well interlaced. In this way, the discrepancy of the source and target domains is reduced. By imposing joint low-rank and sparse constraints on the reconstruction coefficient matrix, the global and local structures of data can be preserved. To enlarge the margins between different classes as much as possible and provide more freedom to diminish the discrepancy, a flexible linear classifier (projection) is obtained by learning a non-negative label relaxation matrix that allows the strict binary label matrix to relax into a slack variable matrix. Our method can avoid a potentially negative transfer by using a sparse matrix to model the noise and, thus, is more robust to different types of noise. We formulate our problem as a constrained low-rankness and sparsity minimization problem and solve it by the inexact augmented Lagrange multiplier method. Extensive experiments on various visual domain adaptation tasks show the superiority of the proposed method over the state-of-the art methods. The MATLAB code of our method will be publicly available at http://www.yongxu.org/lunwen.html.

  1. Learning discriminative features from RGB-D images for gender and ethnicity identification

    Science.gov (United States)

    Azzakhnini, Safaa; Ballihi, Lahoucine; Aboutajdine, Driss

    2016-11-01

    The development of sophisticated sensor technologies gave rise to an interesting variety of data. With the appearance of affordable devices, such as the Microsoft Kinect, depth-maps and three-dimensional data became easily accessible. This attracted many computer vision researchers seeking to exploit this information in classification and recognition tasks. In this work, the problem of face classification in the context of RGB images and depth information (RGB-D images) is addressed. The purpose of this paper is to study and compare some popular techniques for gender recognition and ethnicity classification to understand how much depth data can improve the quality of recognition. Furthermore, we investigate which combination of face descriptors, feature selection methods, and learning techniques is best suited to better exploit RGB-D images. The experimental results show that depth data improve the recognition accuracy for gender and ethnicity classification applications in many use cases.

  2. Skills training to learn discrimination of ABCDE criteria by those at risk of developing melanoma.

    Science.gov (United States)

    Robinson, June K; Turrisi, Rob

    2006-04-01

    To develop skin self-examination skills by improving the use of the ABCDE criteria by those at risk of developing melanoma. Ten single-sex groups of 10 unrelated adults received a knowledge-based intervention followed by skills training. Classroom in the ambulatory care area of a hospital. Patients One hundred unrelated adults with either a personal or family history of melanoma and no previous skin self-examination counseling. Interventions A dermatologist presented information, and each subject read a brochure and reviewed a bookmark. The facilitator led the group discussions about scoring each feature and the decision to seek medical care. Measurement of moles with a ruler and a pencil eraser and the use of an illuminated magnifying lens were demonstrated. Preintervention and postintervention assessments were performed for each intervention. Recognition of A, B, C, D, and E traits. The subjects preferred the bookmark (87% of subjects), opaque ruler (94% of subjects), and lighted magnifying lens (81% of subjects) to reading the brochure, which was felt to take too long. Recognition of border irregularity, color variation, and diameter improved significantly after the intervention. Women recognized color variation more often than men (94% vs 62%; odds ratio [OR], 23.7; 95% confidence interval [CI], 16.1-50.5). Men identified irregular borders more often than women (91% vs 75%; OR, 16.8; 95% CI, 4.5-22.6). Women appropriately decided to see a physician more often than men (81% vs 57%; OR, 13.5; 95% CI, 7.1-28.4). Determining the presence of the A, B, C, and E criteria is challenging for the novice. Skills training aided performance of skin self-examination. Differences in proclivities according to sex suggest that if men and women form partnerships for skin checks, they may learn from each other, and their combined strengths will promote detection of early melanomas.

  3. Language discrimination by Java sparrows.

    Science.gov (United States)

    Watanabe, Shigeru; Yamamoto, Erico; Uozumi, Midori

    2006-07-01

    Java sparrows (Padda oryzivora) were trained to discriminate English from Chinese spoken by a bilingual speaker. They could learn discrimination and showed generalization to new sentences spoken by the same speaker and those spoken by a new speaker. Thus, the birds distinguished between English and Chinese. Although auditory cues for the discrimination were not specified, this is the first evidence that non-mammalian species can discriminate human languages.

  4. Price Discrimination

    OpenAIRE

    Armstrong, M.

    2008-01-01

    This paper surveys recent economic research on price discrimination, both in monopoly and oligopoly markets. Topics include static and dynamic forms of price discrimination, and both final and input markets are considered. Potential antitrust aspects of price discrimination are highlighted throughout the paper. The paper argues that the informational requirements to make accurate policy are very great, and with most forms of price discrimination a laissez-faire policy may be the best availabl...

  5. Differential discriminator

    International Nuclear Information System (INIS)

    Dukhanov, V.I.; Mazurov, I.B.

    1981-01-01

    A principal flowsheet of a differential discriminator intended for operation in a spectrometric circuit with statistical time distribution of pulses is described. The differential discriminator includes four integrated discriminators and a channel of piled-up signal rejection. The presence of the rejection channel enables the discriminator to operate effectively at loads of 14x10 3 pulse/s. The temperature instability of the discrimination thresholds equals 250 μV/ 0 C. The discrimination level changes within 0.1-5 V, the level shift constitutes 0.5% for the filling ratio of 1:10. The rejection coefficient is not less than 90%. Alpha spectrum of the 228 Th source is presented to evaluate the discriminator operation with the rejector. The rejector provides 50 ns time resolution

  6. Selecting the most relevant brain regions to discriminate Alzheimer's disease patients from healthy controls using multiple kernel learning: A comparison across functional and structural imaging modalities and atlases.

    Science.gov (United States)

    Rondina, Jane Maryam; Ferreira, Luiz Kobuti; de Souza Duran, Fabio Luis; Kubo, Rodrigo; Ono, Carla Rachel; Leite, Claudia Costa; Smid, Jerusa; Nitrini, Ricardo; Buchpiguel, Carlos Alberto; Busatto, Geraldo F

    2018-01-01

    Machine learning techniques such as support vector machine (SVM) have been applied recently in order to accurately classify individuals with neuropsychiatric disorders such as Alzheimer's disease (AD) based on neuroimaging data. However, the multivariate nature of the SVM approach often precludes the identification of the brain regions that contribute most to classification accuracy. Multiple kernel learning (MKL) is a sparse machine learning method that allows the identification of the most relevant sources for the classification. By parcelating the brain into regions of interest (ROI) it is possible to use each ROI as a source to MKL (ROI-MKL). We applied MKL to multimodal neuroimaging data in order to: 1) compare the diagnostic performance of ROI-MKL and whole-brain SVM in discriminating patients with AD from demographically matched healthy controls and 2) identify the most relevant brain regions to the classification. We used two atlases (AAL and Brodmann's) to parcelate the brain into ROIs and applied ROI-MKL to structural (T1) MRI, 18 F-FDG-PET and regional cerebral blood flow SPECT (rCBF-SPECT) data acquired from the same subjects (20 patients with early AD and 18 controls). In ROI-MKL, each ROI received a weight (ROI-weight) that indicated the region's relevance to the classification. For each ROI, we also calculated whether there was a predominance of voxels indicating decreased or increased regional activity (for 18 F-FDG-PET and rCBF-SPECT) or volume (for T1-MRI) in AD patients. Compared to whole-brain SVM, the ROI-MKL approach resulted in better accuracies (with either atlas) for classification using 18 F-FDG-PET (92.5% accuracy for ROI-MKL versus 84% for whole-brain), but not when using rCBF-SPECT or T1-MRI. Although several cortical and subcortical regions contributed to discrimination, high ROI-weights and predominance of hypometabolism and atrophy were identified specially in medial parietal and temporo-limbic cortical regions. Also, the weight of

  7. [Effect of space flight factors simulated in ground-based experiments on the behavior, discriminant learning, and exchange of monoamines in different brain structures of rats].

    Science.gov (United States)

    Shtemberg, A S; Lebedeva-Georgievskaia, K V; Matveeva, M I; Kudrin, V S; Narkevich, V B; Klodt, P M; Bazian, A S

    2014-01-01

    Experimental treatment (long-term fractionated γ-irradiation, antiorthostatic hypodynamia, and the combination of these factors) simulating the effect of space flight in ground-based experiments rapidly restored the motor and orienting-investigative activity of animals (rats) in "open-field" tests. The study of the dynamics of discriminant learning of rats of experimental groups did not show significant differences from the control animals. It was found that the minor effect of these factors on the cognitive performance of animals correlated with slight changes in the concentration ofmonoamines in the brain structures responsible for the cognitive, emotional, and motivational functions.

  8. TumorBoost: Normalization of allele-specific tumor copy numbers from a single pair of tumor-normal genotyping microarrays

    Directory of Open Access Journals (Sweden)

    Neuvial Pierre

    2010-05-01

    Full Text Available Abstract Background High-throughput genotyping microarrays assess both total DNA copy number and allelic composition, which makes them a tool of choice for copy number studies in cancer, including total copy number and loss of heterozygosity (LOH analyses. Even after state of the art preprocessing methods, allelic signal estimates from genotyping arrays still suffer from systematic effects that make them difficult to use effectively for such downstream analyses. Results We propose a method, TumorBoost, for normalizing allelic estimates of one tumor sample based on estimates from a single matched normal. The method applies to any paired tumor-normal estimates from any microarray-based technology, combined with any preprocessing method. We demonstrate that it increases the signal-to-noise ratio of allelic signals, making it significantly easier to detect allelic imbalances. Conclusions TumorBoost increases the power to detect somatic copy-number events (including copy-neutral LOH in the tumor from allelic signals of Affymetrix or Illumina origin. We also conclude that high-precision allelic estimates can be obtained from a single pair of tumor-normal hybridizations, if TumorBoost is combined with single-array preprocessing methods such as (allele-specific CRMA v2 for Affymetrix or BeadStudio's (proprietary XY-normalization method for Illumina. A bounded-memory implementation is available in the open-source and cross-platform R package aroma.cn, which is part of the Aroma Project (http://www.aroma-project.org/.

  9. Learning and Transforming Reality: Women from Rosario's Neighborhoods Demand Access to Public Health Services Free of Discrimination

    Science.gov (United States)

    Chiarotti, Susana

    2005-01-01

    This article focuses on the activities of two women's groups in Argentina -- CLADEM and INSGENAR. CLADEM, which has a much broader presence in Latin America, aims to give a feminist perspective to the construction of real democracies with social justice, free of discrimination and with full exercise of human rights. INSGENAR is a local,…

  10. Structural Discrimination

    DEFF Research Database (Denmark)

    Thorsen, Mira Skadegård

    In this article, I discuss structural discrimination, an underrepresented area of study in Danish discrimination and intercultural research. It is defined here as discursive and constitutive, and presented as a central element of my analytical approach. This notion is employed in the with which t...

  11. Sex differences in conditioned stimulus discrimination during context-dependent fear learning and its retrieval in humans: the role of biological sex, contraceptives and menstrual cycle phases.

    Science.gov (United States)

    Lonsdorf, Tina B; Haaker, Jan; Schümann, Dirk; Sommer, Tobias; Bayer, Janine; Brassen, Stefanie; Bunzeck, Nico; Gamer, Matthias; Kalisch, Raffael

    2015-11-01

    Anxiety disorders are more prevalent in women than in men. Despite this sexual dimorphism, most experimental studies are conducted in male participants and studies focusing on sex differences are sparse. In addition, the role of hormonal contraceptives and menstrual cycle phase in fear conditioning and extinction processes remain largely unknown. We investigated sex differences in context-dependent fear acquisition and extinction (day 1) and their retrieval/expression (day 2). Skin conductance responses (SCRs), fear and unconditioned stimulus expectancy ratings were obtained. We included 377 individuals (261 women) in our study. Robust sex differences were observed in all dependent measures. Women generally displayed higher subjective ratings but smaller SCRs than men and showed reduced excitatory/inhibitory conditioned stimulus (CS+/CS-) discrimination in all dependent measures. Furthermore, women using hormonal contraceptives showed reduced SCR CS discrimination on day 2 than men and free-cycling women, while menstrual cycle phase had no effect. Possible limitations include the simultaneous testing of up to 4 participants in cubicles, which might have introduced a social component, and not assessing postexperimental contingency awareness. The response pattern in women shows striking similarity to previously reported sex differences in patients with anxiety. Our results suggest that pronounced deficits in associative discrimination learning and subjective expression of safety information (CS- responses) might underlie higher prevalence and higher symptom rates seen in women with anxiety disorders. The data call for consideration of biological sex and hormonal contraceptive use in future studies and may suggest that targeting inhibitory learning during therapy might aid precision medicine.

  12. Distinct Discrimination Learning Strategies and Their Relation with Spatial Memory and Attentional Control in 4- to 14-Year-Olds

    Science.gov (United States)

    Schmittmann, Verena D.; van der Maas, Han L. J.; Raijmakers, Maartje E. J.

    2012-01-01

    Behavioral, psychophysiological, and neuropsychological studies have revealed large developmental differences in various learning paradigms where learning from positive and negative feedback is essential. The differences are possibly due to the use of distinct strategies that may be related to spatial working memory and attentional control. In…

  13. Spatial Discrimination Reversal Learning in Weanling Rats Is Impaired by Striatal Administration of an NMDA-Receptor Antagonist

    Science.gov (United States)

    Watson, Deborah J.; Stanton, Mark E.

    2009-01-01

    The striatum plays a major role in both motor control and learning and memory, including executive function and "behavioral flexibility." Lesion, temporary inactivation, and infusion of an N-methyl-d-aspartate (NMDA)-receptor antagonist into the dorsomedial striatum (dmSTR) impair reversal learning in adult rats. Systemic administration of MK-801…

  14. Genetic Discrimination

    Science.gov (United States)

    Skip to main content Genetic Discrimination Enter Search Term(s): Español Research Funding An Overview Bioinformatics Current Grants Education and Training Funding Extramural Research News Features Funding Divisions ...

  15. SEISMIC DISCRIMINATION

    Science.gov (United States)

    a potential new discriminant , and to study depth phases. Surface- and body-wave magnitude data have been obtained and used to study regionalization...and signal equalization studies initiated. Upgrading of software and hardware facilities has continued. (Author)

  16. Unsupervised learning of generative and discriminative weights encoding elementary image components in a predictive coding model of cortical function.

    Science.gov (United States)

    Spratling, M W

    2012-01-01

    A method is presented for learning the reciprocal feedforward and feedback connections required by the predictive coding model of cortical function. When this method is used, feedforward and feedback connections are learned simultaneously and independently in a biologically plausible manner. The performance of the proposed algorithm is evaluated by applying it to learning the elementary components of artificial and natural images. For artificial images, the bars problem is employed, and the proposed algorithm is shown to produce state-of-the-art performance on this task. For natural images, components resembling Gabor functions are learned in the first processing stage, and neurons responsive to corners are learned in the second processing stage. The properties of these learned representations are in good agreement with neurophysiological data from V1 and V2. The proposed algorithm demonstrates for the first time that a single computational theory can explain the formation of cortical RFs and also the response properties of cortical neurons once those RFs have been learned.

  17. An assessment of the validity and discrimination of the intensive time-series design by monitoring learning differences between students with different cognitive tendencies

    Science.gov (United States)

    Farnsworth, Carolyn H.; Mayer, Victor J.

    Intensive time-series designs for classroom investigations have been under development since 1975. Studies have been conducted to determine their feasibility (Mayer & Lewis, 1979), their potential for monitoring knowledge acquisition (Mayer & Kozlow, 1980), and the potential threat to validity of the frequency of testing inherent in the design (Mayer & Rojas, 1982). This study, an extension of those previous studies, is an attempt to determine the degree of discrimination the design allows in collecting data on achievement. It also serves as a replication of the Mayer and Kozlow study, an attempt to determine design validity for collecting achievement data. The investigator used her eighth-grade earth science students, from a suburban Columbus (Ohio) junior high school. A multiple-group single intervention time-series design (Glass, Willson, & Gottman, 1975) was adapted to the collection of daily data on achievement in the topic of the intervention, a unit on plate tectonics. Single multiple-choice items were randomly assigned to each of three groups of students, identified on the basis of their ranking on a written test of cognitive level (Lawson, 1978). The top third, or those with formal cognitive tendencies, were compared on the basis of knowledge achievement and understanding achievement with the lowest third of the students, or those with concrete cognitive tendencies, to determine if the data collected in the design would discriminate between the two groups. Several studies (Goodstein & Howe, 1978; Lawson & Renner, 1975) indicated that students with formal cognitive tendencies should learn a formal concept such as plate tectonics with greater understanding than should students with concrete cognitive tendencies. Analyses used were a comparison of regression lines in each of the three study stages: baseline, intervention, and follow-up; t-tests of means of days summed across each stage; and a time-series analysis program. Statistically significant differences

  18. Fornix transected macaques make fewer perseverative errors than controls during the early stages of learning conditional visuovisual discriminations [corrected].

    Science.gov (United States)

    Kwok, Sze Chai; Buckley, Mark J

    2009-12-14

    Previous studies with macaque monkeys have found rapid learning to be impaired in both spatial (visuospatial) and non-spatial (visuomotor) associative learning tasks after fornix transection. In order to test theories that posit a general role for the fornix in associative learning, we investigated whether monkeys with fornix transection would also be impaired in the rapid acquisition of visuovisual conditional associations. We trained monkeys, postoperatively, on three sets of conditional stimulus-stimulus concurrent associations. Fornix transection did not impair learning of these associations, even in the early stages; to the contrary, animals with fornix transection made significantly fewer perseverative errors during the initial acquisition stages. These results challenge the idea that the hippocampal system plays a general role in the rapid acquisition of all kinds of associative knowledge. We suggest that the lower error rate in the early stages of the non-spatial task in the fornix transected animals may be secondary to an impairment in visuospatial processing; this might act to bias animals away from attempts to learn about spatial strategies for solving novel tasks. Additionally, we observed that fornix transected and control monkeys adopted a Change-shift response strategy in this task; the use of which was found to be fornix independent.

  19. The effects of incidentally learned temporal and spatial predictability on response times and visual fixations during target detection and discrimination.

    Science.gov (United States)

    Beck, Melissa R; Hong, S Lee; van Lamsweerde, Amanda E; Ericson, Justin M

    2014-01-01

    Responses are quicker to predictable stimuli than if the time and place of appearance is uncertain. Studies that manipulate target predictability often involve overt cues to speed up response times. However, less is known about whether individuals will exhibit faster response times when target predictability is embedded within the inter-trial relationships. The current research examined the combined effects of spatial and temporal target predictability on reaction time (RT) and allocation of overt attention in a sustained attention task. Participants responded as quickly as possible to stimuli while their RT and eye movements were measured. Target temporal and spatial predictability were manipulated by altering the number of: 1) different time intervals between a response and the next target; and 2) possible spatial locations of the target. The effects of target predictability on target detection (Experiment 1) and target discrimination (Experiment 2) were tested. For both experiments, shorter RTs as target predictability increased across both space and time were found. In addition, the influences of spatial and temporal target predictability on RT and the overt allocation of attention were task dependent; suggesting that effective orienting of attention relies on both spatial and temporal predictability. These results indicate that stimulus predictability can be increased without overt cues and detected purely through inter-trial relationships over the course of repeated stimulus presentations.

  20. The effects of incidentally learned temporal and spatial predictability on response times and visual fixations during target detection and discrimination.

    Directory of Open Access Journals (Sweden)

    Melissa R Beck

    Full Text Available Responses are quicker to predictable stimuli than if the time and place of appearance is uncertain. Studies that manipulate target predictability often involve overt cues to speed up response times. However, less is known about whether individuals will exhibit faster response times when target predictability is embedded within the inter-trial relationships. The current research examined the combined effects of spatial and temporal target predictability on reaction time (RT and allocation of overt attention in a sustained attention task. Participants responded as quickly as possible to stimuli while their RT and eye movements were measured. Target temporal and spatial predictability were manipulated by altering the number of: 1 different time intervals between a response and the next target; and 2 possible spatial locations of the target. The effects of target predictability on target detection (Experiment 1 and target discrimination (Experiment 2 were tested. For both experiments, shorter RTs as target predictability increased across both space and time were found. In addition, the influences of spatial and temporal target predictability on RT and the overt allocation of attention were task dependent; suggesting that effective orienting of attention relies on both spatial and temporal predictability. These results indicate that stimulus predictability can be increased without overt cues and detected purely through inter-trial relationships over the course of repeated stimulus presentations.

  1. Comparison of learning ability and memory retention in altricial (Bengalese finch, Lonchura striata var. domestica) and precocial (blue-breasted quail, Coturnix chinensis) birds using a color discrimination task.

    Science.gov (United States)

    Ueno, Aki; Suzuki, Kaoru

    2014-02-01

    The present study sought to assess the potential application of avian models with different developmental modes to studies on cognition and neuroscience. Six altricial Bengalese finches (Lonchura striata var. domestica), and eight precocial blue-breasted quails (Coturnix chinensis) were presented with color discrimination tasks to compare their respective faculties for learning and memory retention within the context of the two developmental modes. Tasks consisted of presenting birds with discriminative cues in the form of colored feeder lids, and birds were considered to have learned a task when 80% of their attempts at selecting the correctly colored lid in two consecutive blocks of 10 trials were successful. All of the finches successfully performed the required experimental tasks, whereas only half of the quails were able to execute the same tasks. In the learning test, finches required significantly fewer trials than quails to learn the task (finches: 13.5 ± 9.14 trials, quails: 45.8 ± 4.35 trials, P memory retention tests, which were conducted 45 days after the learning test, finches retained the ability to discriminate between colors correctly (95.0 ± 4.47%), whereas quails did not retain any memory of the experimental procedure and so could not be tested. These results suggested that altricial and precocial birds both possess the faculty for learning and retaining discrimination-type tasks, but that altricial birds perform better than precocial birds in both faculties. The present findings imply that developmental mode is an important consideration for assessing the suitability of bird species for particular experiments. © 2013 Japanese Society of Animal Science.

  2. Multi-modal, Multi-measure, and Multi-class Discrimination of ADHD with Hierarchical Feature Extraction and Extreme Learning Machine Using Structural and Functional Brain MRI.

    Science.gov (United States)

    Qureshi, Muhammad Naveed Iqbal; Oh, Jooyoung; Min, Beomjun; Jo, Hang Joon; Lee, Boreom

    2017-01-01

    Structural and functional MRI unveil many hidden properties of the human brain. We performed this multi-class classification study on selected subjects from the publically available attention deficit hyperactivity disorder ADHD-200 dataset of patients and healthy children. The dataset has three groups, namely, ADHD inattentive, ADHD combined, and typically developing. We calculated the global averaged functional connectivity maps across the whole cortex to extract anatomical atlas parcellation based features from the resting-state fMRI (rs-fMRI) data and cortical parcellation based features from the structural MRI (sMRI) data. In addition, the preprocessed image volumes from both of these modalities followed an ANOVA analysis separately using all the voxels. This study utilized the average measure from the most significant regions acquired from ANOVA as features for classification in addition to the multi-modal and multi-measure features of structural and functional MRI data. We extracted most discriminative features by hierarchical sparse feature elimination and selection algorithm. These features include cortical thickness, image intensity, volume, cortical thickness standard deviation, surface area, and ANOVA based features respectively. An extreme learning machine performed both the binary and multi-class classifications in comparison with support vector machines. This article reports prediction accuracy of both unimodal and multi-modal features from test data. We achieved 76.190% ( p features may improve the accuracy of the ADHD differential diagnosis.

  3. Medical students’ perception of lesbian, gay, bisexual, and transgender (LGBT) discrimination in their learning environment and their self-reported comfort level for caring for LGBT patients: a survey study

    Science.gov (United States)

    Nama, Nassr; MacPherson, Paul; Sampson, Margaret; McMillan, Hugh J.

    2017-01-01

    ABSTRACT Background: Historically, medical students who are lesbian, gay, bisexual or transgendered (LGBT) report higher rates of social stress, depression, and anxiety, while LGBT patients have reported discrimination and poorer access to healthcare. Objective: The objectives of this study were: (1) to assess if medical students have perceived discrimination in their learning environment and; (2) to determine self-reported comfort level for caring for LGBT patients. Design: Medical students at the University of Ottawa (N = 671) were contacted via email and invited to complete a confidential web-based survey. Results: Response rate was 15.4% (103/671). This included 66 cis-gender heterosexuals (64.1%) and 37 LGBT students (35.9%). Anti-LGBT discrimination had been witnessed by 14.6% and heterosexism by 31.1% of respondents. Anti-LGBT discrimination most often originated from fellow medical students. Respondents who self-identified as LGBT were more likely to have perceived heterosexism (favoring opposite-sex relationships) (OR = 8.2, p LGBT discrimination (OR = 6.6, p = 0.002). While half of LGBT students shared their status with all classmates (51.4%), they were more likely to conceal this from staff physicians (OR = 27.2, p = 0.002). Almost half of medical students (41.7%) reported anti-LGBT jokes, rumors, and/or bullying by fellow medical students and/or other members of the healthcare team. Still, most respondents indicated that they felt comfortable with and capable of providing medical care to LGBT patients (≥83.5%), and were interested in further education around LGBT health issues (84.5%). Conclusion: Anti-LGBT discrimination and heterosexism are noted by medical students, indicating a suboptimal learning environment for LGBT students. Nonetheless, students report a high level of comfort and confidence providing health care to LGBT patients. PMID:28853327

  4. Medical students' perception of lesbian, gay, bisexual, and transgender (LGBT) discrimination in their learning environment and their self-reported comfort level for caring for LGBT patients: a survey study.

    Science.gov (United States)

    Nama, Nassr; MacPherson, Paul; Sampson, Margaret; McMillan, Hugh J

    2017-01-01

    Historically, medical students who are lesbian, gay, bisexual or transgendered (LGBT) report higher rates of social stress, depression, and anxiety, while LGBT patients have reported discrimination and poorer access to healthcare. The objectives of this study were: (1) to assess if medical students have perceived discrimination in their learning environment and; (2) to determine self-reported comfort level for caring for LGBT patients. Medical students at the University of Ottawa (N = 671) were contacted via email and invited to complete a confidential web-based survey. Response rate was 15.4% (103/671). This included 66 cis-gender heterosexuals (64.1%) and 37 LGBT students (35.9%). Anti-LGBT discrimination had been witnessed by 14.6% and heterosexism by 31.1% of respondents. Anti-LGBT discrimination most often originated from fellow medical students. Respondents who self-identified as LGBT were more likely to have perceived heterosexism (favoring opposite-sex relationships) (OR = 8.2, p LGBT discrimination (OR = 6.6, p = 0.002). While half of LGBT students shared their status with all classmates (51.4%), they were more likely to conceal this from staff physicians (OR = 27.2, p = 0.002). Almost half of medical students (41.7%) reported anti-LGBT jokes, rumors, and/or bullying by fellow medical students and/or other members of the healthcare team. Still, most respondents indicated that they felt comfortable with and capable of providing medical care to LGBT patients (≥83.5%), and were interested in further education around LGBT health issues (84.5%). Anti-LGBT discrimination and heterosexism are noted by medical students, indicating a suboptimal learning environment for LGBT students. Nonetheless, students report a high level of comfort and confidence providing health care to LGBT patients.

  5. Pattern recognition in bees : orientation discrimination

    NARCIS (Netherlands)

    Hateren, J.H. van; Srinivasan, M.V.; Wait, P.B.

    1990-01-01

    Honey bees (Apis mellifera, worker) were trained to discriminate between two random gratings oriented perpendicularly to each other. This task was quickly learned with vertical, horizontal, and oblique gratings. After being trained on perpendicularly-oriented random gratings, bees could discriminate

  6. Price Discrimination and Resale: A Classroom Experiment

    Science.gov (United States)

    Basuchoudhary, Atin; Metcalf, Christopher; Pommerenke, Kai; Reiley, David; Rojas, Christian; Rostek, Marzena; Stodder, James

    2008-01-01

    The authors present a classroom experiment designed to illustrate key concepts of third-degree price discrimination. By participating as buyers and sellers, students actively learn (1) how group pricing differs from uniform pricing, (2) how resale between buyers limits a seller's ability to price discriminate, and (3) how preventing price…

  7. Multimodal Discrimination of Schizophrenia Using Hybrid Weighted Feature Concatenation of Brain Functional Connectivity and Anatomical Features with an Extreme Learning Machine

    Directory of Open Access Journals (Sweden)

    Muhammad Naveed Iqbal Qureshi

    2017-09-01

    Full Text Available Multimodal features of structural and functional magnetic resonance imaging (MRI of the human brain can assist in the diagnosis of schizophrenia. We performed a classification study on age, sex, and handedness-matched subjects. The dataset we used is publicly available from the Center for Biomedical Research Excellence (COBRE and it consists of two groups: patients with schizophrenia and healthy controls. We performed an independent component analysis and calculated global averaged functional connectivity-based features from the resting-state functional MRI data for all the cortical and subcortical anatomical parcellation. Cortical thickness along with standard deviation, surface area, volume, curvature, white matter volume, and intensity measures from the cortical parcellation, as well as volume and intensity from sub-cortical parcellation and overall volume of cortex features were extracted from the structural MRI data. A novel hybrid weighted feature concatenation method was used to acquire maximal 99.29% (P < 0.0001 accuracy which preserves high discriminatory power through the weight of the individual feature type. The classification was performed by an extreme learning machine, and its efficiency was compared to linear and non-linear (radial basis function support vector machines, linear discriminant analysis, and random forest bagged tree ensemble algorithms. This article reports the predictive accuracy of both unimodal and multimodal features after 10-by-10-fold nested cross-validation. A permutation test followed the classification experiment to assess the statistical significance of the classification results. It was concluded that, from a clinical perspective, this feature concatenation approach may assist the clinicians in schizophrenia diagnosis.

  8. Intra-individual gait patterns across different time-scales as revealed by means of a supervised learning model using kernel-based discriminant regression.

    Science.gov (United States)

    Horst, Fabian; Eekhoff, Alexander; Newell, Karl M; Schöllhorn, Wolfgang I

    2017-01-01

    Traditionally, gait analysis has been centered on the idea of average behavior and normality. On one hand, clinical diagnoses and therapeutic interventions typically assume that average gait patterns remain constant over time. On the other hand, it is well known that all our movements are accompanied by a certain amount of variability, which does not allow us to make two identical steps. The purpose of this study was to examine changes in the intra-individual gait patterns across different time-scales (i.e., tens-of-mins, tens-of-hours). Nine healthy subjects performed 15 gait trials at a self-selected speed on 6 sessions within one day (duration between two subsequent sessions from 10 to 90 mins). For each trial, time-continuous ground reaction forces and lower body joint angles were measured. A supervised learning model using a kernel-based discriminant regression was applied for classifying sessions within individual gait patterns. Discernable characteristics of intra-individual gait patterns could be distinguished between repeated sessions by classification rates of 67.8 ± 8.8% and 86.3 ± 7.9% for the six-session-classification of ground reaction forces and lower body joint angles, respectively. Furthermore, the one-on-one-classification showed that increasing classification rates go along with increasing time durations between two sessions and indicate that changes of gait patterns appear at different time-scales. Discernable characteristics between repeated sessions indicate continuous intrinsic changes in intra-individual gait patterns and suggest a predominant role of deterministic processes in human motor control and learning. Natural changes of gait patterns without any externally induced injury or intervention may reflect continuous adaptations of the motor system over several time-scales. Accordingly, the modelling of walking by means of average gait patterns that are assumed to be near constant over time needs to be reconsidered in the context of

  9. Effects of differential postnatal exposure of the rat cerebellum to x-rays on spatial discrimination learning as a function of age and position preference

    International Nuclear Information System (INIS)

    Peters, K.B.

    1979-01-01

    The aim of the present research was to analyze the effects of postnatal exposure of the cerebellum to x-irradiation on the use of proprioceptive feedback in spatial learning. A total of 337 naive male Long-Evans hooded rats were assigned at birth to one of four treatments: 12-15x, 4-5x, 4-15x and control. Subjects assigned to the 12-15x treatment were exposed to 200R at 12 and 13 days of age, and to 150R at 15 days of age. The subjects exposed to the 4-5x schedule received 200R on days 4 and 5. The 4-15x subjects are exposed to 200R on days 4 and 5, and to 150R on days 7, 9, 11, 13, 15. Subjects from each treatment started spatial discrimination testing in a T-shaped water maze at 30 to 31, 60 to 63, or 180 to 185 days of age. A preference effect was evident in the control, 12-15x and 4-5x subjects, but not in the 4-15x subjects during acquisition testing. Those control, 12-15x and 4-5x subjects trained against their preference made more errors and required more trials to attain acquisition criterion than did those subjects trained toward their preference. The absence of a position preference in the 4-15x subjects is attributed to the absence of the mossy fiber channel of input to the Purkinje cells in this preparation. Deficits in spatial learning were evident in both the 12-15x and 4-15x subjects, the former differing significantly from control subjects and the latter from the 4-5x subjects in the number of trials needed to complete reversal testing and/or the number of errors made during this phase of the testing. It is the upper portion of the molecular layer, absent in the 12-15x and 4-15x preparations, which receives afferent input from the spinal cord

  10. Discriminative learning after uncontrollable shocks

    Directory of Open Access Journals (Sweden)

    Angelica Capelari

    2009-10-01

    Full Text Available O objetivo desse estudo foi investigar se estímulos aversivos não contingentes (incontroláveis produzem interferência em um processo de aprendizagem discriminativa reforçada positivamente. Vinte e quatro ratos foram distribuídos em três grupos (n=8 que diferiram entre si quanto ao tratamento recebido na primeira sessão: choques controláveis (C, incontroláveis (I ou nenhum choque (N. Posteriormente, todos foram submetidos a 10 sessões de treino discriminativo com reforço positivo, em esquema múltiplo-concorrente FR-6/Extinção. Os resultados do treino discriminativo mostraram que, na primeira sessão, a exposição prévia a choques produziu menor frequência de respostas, sendo esse efeito levemente mais acentuado no grupo I; na décima sessão, os grupos não diferiram entre si quanto à frequência de respostas e ao índice discriminativo, que ficou acima de 0,80. O efeito transitório do tratamento com choques incontroláveis, sem interferência a longo prazo no estabelecimento do controle de estímulos por reforçamento positivo, é contrário à generalidade do desamparo aprendido para contextos não aversivos.   Palavras-chave: desamparo aprendido; incontrolabilidade; controle de estímulos.

  11. Discriminative learning after uncontrollable shocks

    OpenAIRE

    Angelica Capelari; Maria Helena Leite Hunziker

    2009-01-01

    O objetivo desse estudo foi investigar se estímulos aversivos não contingentes (incontroláveis) produzem interferência em um processo de aprendizagem discriminativa reforçada positivamente. Vinte e quatro ratos foram distribuídos em três grupos (n=8) que diferiram entre si quanto ao tratamento recebido na primeira sessão: choques controláveis (C), incontroláveis (I) ou nenhum choque (N). Posteriormente, todos foram submetidos a 10 sessões de treino discriminativo com reforço positivo, em esqu...

  12. Discrimination and Anti-discrimination in Denmark

    DEFF Research Database (Denmark)

    Olsen, Tore Vincents

    The purpose of this report is to describe and analyse Danish anti-discrimination legislation and the debate about discrimination in Denmark in order to identify present and future legal challenges. The main focus is the implementation of the EU anti-discrimination directives in Danish law...

  13. Discriminant forest classification method and system

    Science.gov (United States)

    Chen, Barry Y.; Hanley, William G.; Lemmond, Tracy D.; Hiller, Lawrence J.; Knapp, David A.; Mugge, Marshall J.

    2012-11-06

    A hybrid machine learning methodology and system for classification that combines classical random forest (RF) methodology with discriminant analysis (DA) techniques to provide enhanced classification capability. A DA technique which uses feature measurements of an object to predict its class membership, such as linear discriminant analysis (LDA) or Andersen-Bahadur linear discriminant technique (AB), is used to split the data at each node in each of its classification trees to train and grow the trees and the forest. When training is finished, a set of n DA-based decision trees of a discriminant forest is produced for use in predicting the classification of new samples of unknown class.

  14. Selecting the most relevant brain regions to discriminate Alzheimer's disease patients from healthy controls using multiple kernel learning: A comparison across functional and structural imaging modalities and atlases

    Directory of Open Access Journals (Sweden)

    Jane Maryam Rondina

    2018-01-01

    Conclusion: The MKL-ROI approach highlights the high discriminative weight of a subset of brain regions of known relevance to AD, the selection of which contributes to increased classification accuracy when applied to 18F-FDG-PET data. Moreover, the MKL-ROI approach demonstrates that brain regions typically spared in mild stages of AD also contribute substantially in the individual discrimination of AD patients from controls.

  15. Hierarchical Discriminant Analysis.

    Science.gov (United States)

    Lu, Di; Ding, Chuntao; Xu, Jinliang; Wang, Shangguang

    2018-01-18

    The Internet of Things (IoT) generates lots of high-dimensional sensor intelligent data. The processing of high-dimensional data (e.g., data visualization and data classification) is very difficult, so it requires excellent subspace learning algorithms to learn a latent subspace to preserve the intrinsic structure of the high-dimensional data, and abandon the least useful information in the subsequent processing. In this context, many subspace learning algorithms have been presented. However, in the process of transforming the high-dimensional data into the low-dimensional space, the huge difference between the sum of inter-class distance and the sum of intra-class distance for distinct data may cause a bias problem. That means that the impact of intra-class distance is overwhelmed. To address this problem, we propose a novel algorithm called Hierarchical Discriminant Analysis (HDA). It minimizes the sum of intra-class distance first, and then maximizes the sum of inter-class distance. This proposed method balances the bias from the inter-class and that from the intra-class to achieve better performance. Extensive experiments are conducted on several benchmark face datasets. The results reveal that HDA obtains better performance than other dimensionality reduction algorithms.

  16. Hierarchical Discriminant Analysis

    Directory of Open Access Journals (Sweden)

    Di Lu

    2018-01-01

    Full Text Available The Internet of Things (IoT generates lots of high-dimensional sensor intelligent data. The processing of high-dimensional data (e.g., data visualization and data classification is very difficult, so it requires excellent subspace learning algorithms to learn a latent subspace to preserve the intrinsic structure of the high-dimensional data, and abandon the least useful information in the subsequent processing. In this context, many subspace learning algorithms have been presented. However, in the process of transforming the high-dimensional data into the low-dimensional space, the huge difference between the sum of inter-class distance and the sum of intra-class distance for distinct data may cause a bias problem. That means that the impact of intra-class distance is overwhelmed. To address this problem, we propose a novel algorithm called Hierarchical Discriminant Analysis (HDA. It minimizes the sum of intra-class distance first, and then maximizes the sum of inter-class distance. This proposed method balances the bias from the inter-class and that from the intra-class to achieve better performance. Extensive experiments are conducted on several benchmark face datasets. The results reveal that HDA obtains better performance than other dimensionality reduction algorithms.

  17. Pulse duration discriminator

    International Nuclear Information System (INIS)

    Kosakovskij, L.F.

    1980-01-01

    Basic circuits of a discriminator for discrimination of pulses with the duration greater than the preset one, and of a multifunctional discriminator allowing to discriminate pulses with the duration greater (tsub(p)>tsub(s)) and lesser (tsub(p) tsub(s) and with the duration tsub(p) [ru

  18. The Badness of Discrimination

    DEFF Research Database (Denmark)

    Lippert-Rasmussen, Kasper

    2006-01-01

    The most blatant forms of discrimination are morally outrageous and very obviously so; but the nature and boundaries of discrimination are more controversial, and it is not clear whether all forms of discrimination are morally bad; nor is it clear why objectionable cases of discrimination are bad....... In this paper I address these issues. First, I offer a taxonomy of discrimination. I then argue that discrimination is bad, when it is, because it harms people. Finally, I criticize a rival, disrespect-based account according to which discrimination is bad regardless of whether it causes harm....

  19. Paintings discrimination by mice: Different strategies for different paintings.

    Science.gov (United States)

    Watanabe, Shigeru

    2017-09-01

    C57BL/6 mice were trained on simultaneous discrimination of paintings with multiple exemplars, using an operant chamber with a touch screen. The number of exemplars was successively increased up to six. Those mice trained in Kandinsky/Mondrian discrimination showed improved learning and generalization, whereas those trained in Picasso/Renoir discrimination showed no improvements in learning or generalization. These results suggest category-like discrimination in the Kandinsky/Mondrian task, but item-to-item discrimination in the Picasso/Renoir task. Mice maintained their discriminative behavior in a pixelization test with various paintings; however, mice in the Picasso/Renoir task showed poor performance in a test that employed scrambling processing. These results do not indicate that discrimination strategy for any Kandinsky/Mondrian combinations differed from that for any Picasso/Monet combinations but suggest the mice employed different strategies of discrimination tasks depending upon stimuli. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Introduction to multivariate discrimination

    Directory of Open Access Journals (Sweden)

    Kégl Balázs

    2013-07-01

    Full Text Available Multivariate discrimination or classification is one of the best-studied problem in machine learning, with a plethora of well-tested and well-performing algorithms. There are also several good general textbooks [1–9] on the subject written to an average engineering, computer science, or statistics graduate student; most of them are also accessible for an average physics student with some background on computer science and statistics. Hence, instead of writing a generic introduction, we concentrate here on relating the subject to a practitioner experimental physicist. After a short introduction on the basic setup (Section 1 we delve into the practical issues of complexity regularization, model selection, and hyperparameter optimization (Section 2, since it is this step that makes high-complexity non-parametric fitting so different from low-dimensional parametric fitting. To emphasize that this issue is not restricted to classification, we illustrate the concept on a low-dimensional but non-parametric regression example (Section 2.1. Section 3 describes the common algorithmic-statistical formal framework that unifies the main families of multivariate classification algorithms. We explain here the large-margin principle that partly explains why these algorithms work. Section 4 is devoted to the description of the three main (families of classification algorithms, neural networks, the support vector machine, and AdaBoost. We do not go into the algorithmic details; the goal is to give an overview on the form of the functions these methods learn and on the objective functions they optimize. Besides their technical description, we also make an attempt to put these algorithm into a socio-historical context. We then briefly describe some rather heterogeneous applications to illustrate the pattern recognition pipeline and to show how widespread the use of these methods is (Section 5. We conclude the chapter with three essentially open research problems

  1. Introduction to multivariate discrimination

    Science.gov (United States)

    Kégl, Balázs

    2013-07-01

    Multivariate discrimination or classification is one of the best-studied problem in machine learning, with a plethora of well-tested and well-performing algorithms. There are also several good general textbooks [1-9] on the subject written to an average engineering, computer science, or statistics graduate student; most of them are also accessible for an average physics student with some background on computer science and statistics. Hence, instead of writing a generic introduction, we concentrate here on relating the subject to a practitioner experimental physicist. After a short introduction on the basic setup (Section 1) we delve into the practical issues of complexity regularization, model selection, and hyperparameter optimization (Section 2), since it is this step that makes high-complexity non-parametric fitting so different from low-dimensional parametric fitting. To emphasize that this issue is not restricted to classification, we illustrate the concept on a low-dimensional but non-parametric regression example (Section 2.1). Section 3 describes the common algorithmic-statistical formal framework that unifies the main families of multivariate classification algorithms. We explain here the large-margin principle that partly explains why these algorithms work. Section 4 is devoted to the description of the three main (families of) classification algorithms, neural networks, the support vector machine, and AdaBoost. We do not go into the algorithmic details; the goal is to give an overview on the form of the functions these methods learn and on the objective functions they optimize. Besides their technical description, we also make an attempt to put these algorithm into a socio-historical context. We then briefly describe some rather heterogeneous applications to illustrate the pattern recognition pipeline and to show how widespread the use of these methods is (Section 5). We conclude the chapter with three essentially open research problems that are either

  2. Limited taste discrimination in Drosophila.

    Science.gov (United States)

    Masek, Pavel; Scott, Kristin

    2010-08-17

    In the gustatory systems of mammals and flies, different populations of sensory cells recognize different taste modalities, such that there are cells that respond selectively to sugars and others to bitter compounds. This organization readily allows animals to distinguish compounds of different modalities but may limit the ability to distinguish compounds within one taste modality. Here, we developed a behavioral paradigm in Drosophila melanogaster to evaluate directly the tastes that a fly distinguishes. These studies reveal that flies do not discriminate among different sugars, or among different bitter compounds, based on chemical identity. Instead, flies show a limited ability to distinguish compounds within a modality based on intensity or palatability. Taste associative learning, similar to olfactory learning, requires the mushroom bodies, suggesting fundamental similarities in brain mechanisms underlying behavioral plasticity. Overall, these studies provide insight into the discriminative capacity of the Drosophila gustatory system and the modulation of taste behavior.

  3. Giant pandas can discriminate the emotions of human facial pictures

    OpenAIRE

    Li, Youxu; Dai, Qiang; Hou, Rong; Zhang, Zhihe; Chen, Peng; Xue, Rui; Feng, Feifei; Chen, Chao; Liu, Jiabin; Gu, Xiaodong; Zhang, Zejun; Qi, Dunwu

    2017-01-01

    Previous studies have shown that giant pandas (Ailuropoda melanoleuca) can discriminate face-like shapes, but little is known about their cognitive ability with respect to the emotional expressions of humans. We tested whether adult giant pandas can discriminate expressions from pictures of half of a face and found that pandas can learn to discriminate between angry and happy expressions based on global information from the whole face. Young adult pandas (5?7 years old) learned to discriminat...

  4. ALTERATIONS IN THE IMMUNOREACTIVITY FOR MUSCARINIC ACETYLCHOLINE-RECEPTORS AND COLOCALIZED PKC-GAMMA IN MOUSE HIPPOCAMPUS INDUCED BY SPATIAL DISCRIMINATION-LEARNING

    NARCIS (Netherlands)

    VANDERZEE, EA; COMPAAN, JC; BOHUS, B; LUITEN, PGM

    1995-01-01

    This study describes changes in the immunoreactivity for muscarinic: acetylcholine receptors (mAChRs) in the hippocampus of mice in relation to spatial discrimination behavior, employing the monoclonal antibody M35 raised against purified bovine mAChR protein. Performance in a hole hoard in which

  5. Airline Price Discrimination

    OpenAIRE

    Stacey, Brian

    2015-01-01

    Price discrimination enjoys a long history in the airline industry. Borenstein (1989) discusses price discrimination through frequent flyer programs from 1985 as related to the Piedmont-US Air merger, price discrimination strategies have grown in size and scope since then. From Saturday stay over requirements to varying costs based on time of purchase, the airline industry is uniquely situated to enjoy the fruits of price discrimination.

  6. Pulse-width discriminators

    International Nuclear Information System (INIS)

    Budyashov, Yu.G.; Grebenyuk, V.M.; Zinov, V.G.

    1978-01-01

    A pulse duration discriminator is described which is intended for processing signals from multilayer scintillators. The basic elements of the scintillator are: an input gate, a current generator, an integrating capacitor, a Schmidt trigger and an anticoincidence circuit. The basic circuit of the discriminator and its time diagrams explaining its operating are given. The discriminator is based on microcircuits. Pulse duration discrimination threshold changes continuously from 20 to 100 ns, while its amplitude threshold changes within 20 to 100 mV. The temperature instability of discrimination thresholds (both in pulse width and in amplitude) is better than 0.1 per cent/deg C

  7. LABOR DISCRIMINATION IN BULGARIA

    Directory of Open Access Journals (Sweden)

    Vyara Slavyanska

    2017-03-01

    Full Text Available Labor discrimination is a phenomenon with very serious social and economic consequences, which has increased actuality and importance in Bulgaria nowadays. Because of the high price of discrimination, building effective anti-discrimination legislation occupies a special place in the policy of the European Union. Despite the European directives, the presence of anti-discrimination legislation and the broadly declared anti-discrimination inclinations in our country, these are absolutely not enough for providing environment of equality, with a climate of respect and tolerance to the differences. It turns out that certain groups are definitely victims of labor discrimination. In this connection the present article consecutively identifies these groups, as well as the reasons for their discrimination, underlining the necessity and benefits of the integration of the different.

  8. Quantifying explainable discrimination and removing illegal discrimination in automated decision making

    KAUST Repository

    Kamiran, Faisal

    2012-11-18

    Recently, the following discrimination-aware classification problem was introduced. Historical data used for supervised learning may contain discrimination, for instance, with respect to gender. The question addressed by discrimination-aware techniques is, given sensitive attribute, how to train discrimination-free classifiers on such historical data that are discriminative, with respect to the given sensitive attribute. Existing techniques that deal with this problem aim at removing all discrimination and do not take into account that part of the discrimination may be explainable by other attributes. For example, in a job application, the education level of a job candidate could be such an explainable attribute. If the data contain many highly educated male candidates and only few highly educated women, a difference in acceptance rates between woman and man does not necessarily reflect gender discrimination, as it could be explained by the different levels of education. Even though selecting on education level would result in more males being accepted, a difference with respect to such a criterion would not be considered to be undesirable, nor illegal. Current state-of-the-art techniques, however, do not take such gender-neutral explanations into account and tend to overreact and actually start reverse discriminating, as we will show in this paper. Therefore, we introduce and analyze the refined notion of conditional non-discrimination in classifier design. We show that some of the differences in decisions across the sensitive groups can be explainable and are hence tolerable. Therefore, we develop methodology for quantifying the explainable discrimination and algorithmic techniques for removing the illegal discrimination when one or more attributes are considered as explanatory. Experimental evaluation on synthetic and real-world classification datasets demonstrates that the new techniques are superior to the old ones in this new context, as they succeed in

  9. Differences in phonetic discrimination stem from differences in psychoacoustic abilities in learning the sounds of a second language: Evidence from ERP research.

    Science.gov (United States)

    Lin, Yi; Fan, Ruolin; Mo, Lei

    2017-01-01

    The scientific community has been divided as to the origin of individual differences in perceiving the sounds of a second language (L2). There are two alternative explanations: a general psychoacoustic origin vs. a speech-specific one. A previous study showed that such individual variability is linked to the perceivers' speech-specific capabilities, rather than the perceivers' psychoacoustic abilities. However, we assume that the selection of participants and parameters of sound stimuli might not appropriate. Therefore, we adjusted the sound stimuli and recorded event-related potentials (ERPs) from two groups of early, proficient Cantonese (L1)-Mandarin (L2) bilinguals who differed in their mastery of the Mandarin (L2) phonetic contrast /in-ing/, to explore whether the individual differences in perceiving L2 stem from participants' ability to discriminate various pure tones (frequency, duration and pattern). To precisely measure the participants' acoustic discrimination, mismatch negativity (MMN) elicited by the oddball paradigm was recorded in the experiment. The results showed that significant differences between good perceivers (GPs) and poor perceivers (PPs) were found in the three general acoustic conditions (frequency, duration and pattern), and the MMN amplitude for GP was significantly larger than for PP. Therefore, our results support a general psychoacoustic origin of individual variability in L2 phonetic mastery.

  10. Differences in phonetic discrimination stem from differences in psychoacoustic abilities in learning the sounds of a second language: Evidence from ERP research.

    Directory of Open Access Journals (Sweden)

    Yi Lin

    Full Text Available The scientific community has been divided as to the origin of individual differences in perceiving the sounds of a second language (L2. There are two alternative explanations: a general psychoacoustic origin vs. a speech-specific one. A previous study showed that such individual variability is linked to the perceivers' speech-specific capabilities, rather than the perceivers' psychoacoustic abilities. However, we assume that the selection of participants and parameters of sound stimuli might not appropriate. Therefore, we adjusted the sound stimuli and recorded event-related potentials (ERPs from two groups of early, proficient Cantonese (L1-Mandarin (L2 bilinguals who differed in their mastery of the Mandarin (L2 phonetic contrast /in-ing/, to explore whether the individual differences in perceiving L2 stem from participants' ability to discriminate various pure tones (frequency, duration and pattern. To precisely measure the participants' acoustic discrimination, mismatch negativity (MMN elicited by the oddball paradigm was recorded in the experiment. The results showed that significant differences between good perceivers (GPs and poor perceivers (PPs were found in the three general acoustic conditions (frequency, duration and pattern, and the MMN amplitude for GP was significantly larger than for PP. Therefore, our results support a general psychoacoustic origin of individual variability in L2 phonetic mastery.

  11. Biomarkers that Discriminate Multiple Myeloma Patients with or without Skeletal Involvement Detected Using SELDI-TOF Mass Spectrometry and Statistical and Machine Learning Tools

    Directory of Open Access Journals (Sweden)

    Sudeepa Bhattacharyya

    2006-01-01

    Full Text Available Multiple Myeloma (MM is a severely debilitating neoplastic disease of B cell origin, with the primary source of morbidity and mortality associated with unrestrained bone destruction. Surface enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS was used to screen for potential biomarkers indicative of skeletal involvement in patients with MM. Serum samples from 48 MM patients, 24 with more than three bone lesions and 24 with no evidence of bone lesions were fractionated and analyzed in duplicate using copper ion loaded immobilized metal affinity SELDI chip arrays. The spectra obtained were compiled, normalized, and mass peaks with mass-to-charge ratios (m/z between 2000 and 20,000 Da identified. Peak information from all fractions was combined together and analyzed using univariate statistics, as well as a linear, partial least squares discriminant analysis (PLS-DA, and a non-linear, random forest (RF, classification algorithm. The PLS-DA model resulted in prediction accuracy between 96–100%, while the RF model was able to achieve a specificity and sensitivity of 87.5% each. Both models as well as multiple comparison adjusted univariate analysis identified a set of four peaks that were the most discriminating between the two groups of patients and hold promise as potential biomarkers for future diagnostic and/or therapeutic purposes.

  12. Quantum-state discrimination

    International Nuclear Information System (INIS)

    Roa, Luis; Retamal, Juan Carlos; Saavedra, Carlos

    2002-01-01

    A proposal for a physical implementation of a quantum-state discrimination protocol using an ion in a linear trap is studied, where two nonorthogonal quantum states are codified using two electronic states of the ion. In addition, a protocol is given for discriminating superpositions of nonorthogonal entangled states between ions inside widely separated optical cavities. The discrimination protocol is extended to the case of N linearly independent nonorthogonal quantum states lying in a space of 2N-1 dimensions

  13. Socially-Tolerable Discrimination

    OpenAIRE

    Amegashie, J. Atsu

    2008-01-01

    History is replete with overt discrimination on the basis of race, gender, age, citizenship, ethnicity, marital status, academic performance, health status, volume of market transactions, religion, sexual orientation, etc. However, these forms of discrimination are not equally tolerable. For example, discrimination based on immutable or prohibitively unalterable characteristics such as race, gender, or ethnicity is much less acceptable. Why? I develop a simple rent-seeking model of conflict w...

  14. Giant pandas can discriminate the emotions of human facial pictures.

    Science.gov (United States)

    Li, Youxu; Dai, Qiang; Hou, Rong; Zhang, Zhihe; Chen, Peng; Xue, Rui; Feng, Feifei; Chen, Chao; Liu, Jiabin; Gu, Xiaodong; Zhang, Zejun; Qi, Dunwu

    2017-08-16

    Previous studies have shown that giant pandas (Ailuropoda melanoleuca) can discriminate face-like shapes, but little is known about their cognitive ability with respect to the emotional expressions of humans. We tested whether adult giant pandas can discriminate expressions from pictures of half of a face and found that pandas can learn to discriminate between angry and happy expressions based on global information from the whole face. Young adult pandas (5-7 years old) learned to discriminate expressions more quickly than older individuals (8-16 years old), but no significant differences were found between females and males. These results suggest that young adult giant pandas are better at discriminating emotional expressions of humans. We showed for the first time that the giant panda, can discriminate the facial expressions of humans. Our results can also be valuable for the daily care and management of captive giant pandas.

  15. Discriminating the Mediterranean Pinus spp. using the land surface phenology extracted from the whole MODIS NDVI time series and machine learning algorithms

    Science.gov (United States)

    Rodriguez-Galiano, Victor; Aragones, David; Caparros-Santiago, Jose A.; Navarro-Cerrillo, Rafael M.

    2017-10-01

    Land surface phenology (LSP) can improve the characterisation of forest areas and their change processes. The aim of this work was: i) to characterise the temporal dynamics in Mediterranean Pinus forests, and ii) to evaluate the potential of LSP for species discrimination. The different experiments were based on 679 mono-specific plots for the 5 native species on the Iberian Peninsula: P. sylvestris, P. pinea, P. halepensis, P. nigra and P. pinaster. The entire MODIS NDVI time series (2000-2016) of the MOD13Q1 product was used to characterise phenology. The following phenological parameters were extracted: the start, end and median days of the season, and the length of the season in days, as well as the base value, maximum value, amplitude and integrated value. Multi-temporal metrics were calculated to synthesise the inter-annual variability of the phenological parameters. The species were discriminated by the application of Random Forest (RF) classifiers from different subsets of variables: model 1) NDVI-smoothed time series, model 2) multi-temporal metrics of the phenological parameters, and model 3) multi-temporal metrics and the auxiliary physical variables (altitude, slope, aspect and distance to the coastline). Model 3 was the best, with an overall accuracy of 82%, a kappa coefficient of 0.77 and whose most important variables were: elevation, coast distance, and the end and start days of the growing season. The species that presented the largest errors was P. nigra, (kappa= 0.45), having locations with a similar behaviour to P. sylvestris or P. pinaster.

  16. Decision theory for discrimination-aware classification

    KAUST Repository

    Kamiran, Faisal

    2012-12-01

    Social discrimination (e.g., against females) arising from data mining techniques is a growing concern worldwide. In recent years, several methods have been proposed for making classifiers learned over discriminatory data discriminationaware. However, these methods suffer from two major shortcomings: (1) They require either modifying the discriminatory data or tweaking a specific classification algorithm and (2) They are not flexible w.r.t. discrimination control and multiple sensitive attribute handling. In this paper, we present two solutions for discrimination-aware classification that neither require data modification nor classifier tweaking. Our first and second solutions exploit, respectively, the reject option of probabilistic classifier(s) and the disagreement region of general classifier ensembles to reduce discrimination. We relate both solutions with decision theory for better understanding of the process. Our experiments using real-world datasets demonstrate that our solutions outperform existing state-ofthe-art methods, especially at low discrimination which is a significant advantage. The superior performance coupled with flexible control over discrimination and easy applicability to multiple sensitive attributes makes our solutions an important step forward in practical discrimination-aware classification. © 2012 IEEE.

  17. Flash-Type Discrimination

    Science.gov (United States)

    Koshak, William J.

    2010-01-01

    This viewgraph presentation describes the significant progress made in the flash-type discrimination algorithm development. The contents include: 1) Highlights of Progress for GLM-R3 Flash-Type discrimination Algorithm Development; 2) Maximum Group Area (MGA) Data; 3) Retrieval Errors from Simulations; and 4) Preliminary Global-scale Retrieval.

  18. Digital voltage discriminator

    International Nuclear Information System (INIS)

    Zhou Zhicheng

    1992-01-01

    A digital voltage discriminator is described, which is synthesized by digital comparator and ADC. The threshold is program controllable with high stability. Digital region of confusion is approximately equal to 1.5 LSB. This discriminator has a single channel analyzer function model with channel width of 1.5 LSB

  19. INTERSECTIONAL DISCRIMINATION AGAINST CHILDREN

    DEFF Research Database (Denmark)

    Ravnbøl, Camilla Ida

    This paper adds a perspective to existing research on child protection by engaging in a debate on intersectional discrimination and its relationship to child protection. The paper has a twofold objective, (1) to further establish intersectionality as a concept to address discrimination against ch...... children, and (2) to illustrate the importance of addressing intersectionality within rights-based programmes of child protection....

  20. Discrimination against Black Students

    Science.gov (United States)

    Aloud, Ashwaq; Alsulayyim, Maryam

    2016-01-01

    Discrimination is a structured way of abusing people based on racial differences, hence barring them from accessing wealth, political participation and engagement in many spheres of human life. Racism and discrimination are inherently rooted in institutions in the society, the problem has spread across many social segments of the society including…

  1. Discrimination and delusional ideation

    NARCIS (Netherlands)

    Janssen, I.C.M.; Hanssen, M.S.S.; Bak, M.L.F.J.; Bijl, R.V.; Graaf, R. de; Vollebergh, W.A.M.; McKenzie, K.; Os, J. van

    2003-01-01

    Background In the UK and The Netherlands, people with high rates of psychosis are chronically exposed to discrimination. Aims To test whether perceived discrimination is associated longitudinally with onset of psychosis. Method A 3-year prospective study of cohorts with no history of psychosis and

  2. Discrimination and delusional ideation.

    Science.gov (United States)

    Janssen, I; Hanssen, M; Bak, M; Bijl, R V; de Graaf, R; Vollebergh, W; McKenzie, K; van Os, J

    2003-01-01

    In the UK and The Netherlands, people with high rates of psychosis are chronically exposed to discrimination. To test whether perceived discrimination is associated longitudinally with onset of psychosis. A 3-year prospective study of cohorts with no history of psychosis and differential rates of reported discrimination on the basis of age, gender, disability, appearance, skin colour or ethnicity and sexual orientation was conducted in the Dutch general population (n=4076). The main outcome was onset of psychotic symptoms (delusions and hallucinations). The rate of delusional ideation was 0.5% (n=19) in those who did not report discrimination, 0.9% (n=4) in those who reported discrimination in one domain, and 2.7% (n=3) in those who reported discrimination in more than one domain (exact P=0.027). This association remained after adjustment for possible confounders. No association was found between baseline discrimination and onset of hallucinatory experiences. Perceived discrimination may induce delusional ideation and thus contribute to the high observed rates of psychotic disorder in exposed minority populations.

  3. The relationships between major lifetime discrimination, everyday discrimination, and mental health in three racial and ethnic groups of older adults.

    Science.gov (United States)

    Ayalon, Liat; Gum, Amber M

    2011-07-01

    To evaluate the relationships between perceived exposure to major lifetime discrimination, everyday discrimination, and mental health in three racial/ethnic groups of older adults. The Health and Retirement Study is a nationally representative sample of individuals 50 years and older living in the United States. A total of 6455 Whites, 716 Latinos, and 1214 Blacks were eligible to complete a self-report psychosocial questionnaire in the year 2006. Whereas 30% of the general population reported at least one type of major lifetime discrimination, almost 45% of Black older adults reported such discrimination. Relative to the other two racial/ethnic groups (82% Whites, 82.6% Blacks), Latinos were significantly less likely to report any everyday discrimination (64.2%), whereas Blacks reported the greatest frequency of everyday discrimination. Whites reported the highest levels of life satisfaction and the lowest levels of depressive symptoms. Relative to major lifetime discrimination, everyday discrimination had a somewhat stronger correlation with mental health indicators. The relationships between discrimination and mental health outcomes were stronger for White compared to Black older adults, although everyday discrimination was still significantly associated with outcomes for Black older adults. Black older adults experience the greatest number of discriminative events, but weaker associated mental health outcomes. This could be because they have become accustomed to these experiences, benefit from social or cultural resources that serve as buffers, or selective survival, with the present sample capturing only the most resilient older adults who have learned to cope with the deleterious effects of discrimination.

  4. Introduction to integral discriminants

    International Nuclear Information System (INIS)

    Morozov, A.; Shakirov, Sh.

    2009-01-01

    The simplest partition function, associated with homogeneous symmetric forms S of degree r in n variables, is integral discriminant J n|r (S) = ∫e -S(x 1 ,...,x n ) dx 1 ...dx n . Actually, S-dependence remains the same if e -S in the integrand is substituted by arbitrary function f(S), i.e. integral discriminant is a characteristic of the form S itself, and not of the averaging procedure. The aim of the present paper is to calculate J n|r in a number of non-Gaussian cases. Using Ward identities - linear differential equations, satisfied by integral discriminants - we calculate J 2|3 ,J 2|4 ,J 2|5 and J 3|3 . In all these examples, integral discriminant appears to be a generalized hypergeometric function. It depends on several SL(n) invariants of S, with essential singularities controlled by the ordinary algebraic discriminant of S.

  5. Introduction to integral discriminants

    Science.gov (United States)

    Morozov, A.; Shakirov, Sh.

    2009-12-01

    The simplest partition function, associated with homogeneous symmetric forms S of degree r in n variables, is integral discriminant Jn|r(S) = ∫e-S(x1,...,xn)dx1...dxn. Actually, S-dependence remains the same if e-S in the integrand is substituted by arbitrary function f(S), i.e. integral discriminant is a characteristic of the form S itself, and not of the averaging procedure. The aim of the present paper is to calculate Jn|r in a number of non-Gaussian cases. Using Ward identities — linear differential equations, satisfied by integral discriminants — we calculate J2|3,J2|4,J2|5 and J3|3. In all these examples, integral discriminant appears to be a generalized hypergeometric function. It depends on several SL(n) invariants of S, with essential singularities controlled by the ordinary algebraic discriminant of S.

  6. Discrimination in Modern Society

    OpenAIRE

    Schekach, E. V.; Щекач, Е. В.

    2013-01-01

    Issues of discrimination in modern society are examined in the article. Types of discrimination, ways of demonstration, methods of combating discrimination and inequality are described. Particular attention is paid to the legal basis and the real life stories, which serve as a material base for judgments how to prevent discrimination. Possible ways are suggested to eliminate such a negative phenomenon of society like discrimination. Статья посвящена вопросам дискриминации в современном общ...

  7. Discriminative graph embedding for label propagation.

    Science.gov (United States)

    Nguyen, Canh Hao; Mamitsuka, Hiroshi

    2011-09-01

    In many applications, the available information is encoded in graph structures. This is a common problem in biological networks, social networks, web communities and document citations. We investigate the problem of classifying nodes' labels on a similarity graph given only a graph structure on the nodes. Conventional machine learning methods usually require data to reside in some Euclidean spaces or to have a kernel representation. Applying these methods to nodes on graphs would require embedding the graphs into these spaces. By embedding and then learning the nodes on graphs, most methods are either flexible with different learning objectives or efficient enough for large scale applications. We propose a method to embed a graph into a feature space for a discriminative purpose. Our idea is to include label information into the embedding process, making the space representation tailored to the task. We design embedding objective functions that the following learning formulations become spectral transforms. We then reformulate these spectral transforms into multiple kernel learning problems. Our method, while being tailored to the discriminative tasks, is efficient and can scale to massive data sets. We show the need of discriminative embedding on some simulations. Applying to biological network problems, our method is shown to outperform baselines.

  8. Learning Statistical Patterns in Relational Data Using Probabilistic Relational Models

    National Research Council Canada - National Science Library

    Koller, Daphne

    2005-01-01

    .... This effort focused on developing undirected probabilistic models for representing and learning graph patterns, learning patterns involving links between objects, learning discriminative models...

  9. Action Recognition Using Discriminative Structured Trajectory Groups

    KAUST Repository

    Atmosukarto, Indriyati

    2015-01-06

    In this paper, we develop a novel framework for action recognition in videos. The framework is based on automatically learning the discriminative trajectory groups that are relevant to an action. Different from previous approaches, our method does not require complex computation for graph matching or complex latent models to localize the parts. We model a video as a structured bag of trajectory groups with latent class variables. We model action recognition problem in a weakly supervised setting and learn discriminative trajectory groups by employing multiple instance learning (MIL) based Support Vector Machine (SVM) using pre-computed kernels. The kernels depend on the spatio-temporal relationship between the extracted trajectory groups and their associated features. We demonstrate both quantitatively and qualitatively that the classification performance of our proposed method is superior to baselines and several state-of-the-art approaches on three challenging standard benchmark datasets.

  10. Behavioral Correlates of 50-kHz Ultrasonic Vocalizations in Rats: Progressive Operant Discrimination Learning Reduces Frequency Modulation and Increases Overall Amplitude

    Directory of Open Access Journals (Sweden)

    Shoko Yuki

    2014-11-01

    Full Text Available Ultrasonic vocalizations (USVs in rats are thought to contain ecological signals reflecting emotional states. These USVs are centered on 50-kHz, and frequency modulation (FM is hypothesized to indicate positive emotion; however, results from recent studies are inconsistent with this hypothesis. We suspected that such inconsistencies might result from ambiguity in defining frequency modulation, and problems with acoustic analyses and behavioral protocols. We addressed these problems by applying quantitative methods for USV analyses and using a food reward operant paradigm. Our results revealed that frequency modulation varied according to the degree of positive outcomes, but the direction of change was opposite to what had been observed in previous studies. The FM in 50-kHz USVs decreased as animals learned the task and obtained more reinforcement, while USV amplitude increased as learning progressed. To reconcile these results with those from prior studies, we suggest that FM in 50-kHz USVs should be taken as an index of reward prediction errors, and USV amplitude should be considered as an index of positive emotion.

  11. Rapid analysis of microbial systems using vibrational spectroscopy and supervised learning methods: application to the discrimination between methicillin-resistant and methicillin-susceptible Staphy

    Science.gov (United States)

    Goodacre, Royston; Rooney, Paul J.; Kell, Douglas B.

    1998-04-01

    FTIR spectra were obtained from 15 methicillin-resistant and 22 methicillin-susceptible Staphylococcus aureus strains using our DRASTIC approach. Cluster analysis showed that the major source of variation between the IR spectra was not due to their resistance or susceptibility to methicillin; indeed early studies suing pyrolysis mass spectrometry had shown that this unsupervised analysis gave information on the phage group of the bacteria. By contrast, artificial neural networks, based on a supervised learning, could be trained to recognize those aspects of the IR spectra which differentiated methicillin-resistant from methicillin- susceptible strains. These results give the first demonstration that the combination of FTIR with neural networks can provide a very rapid and accurate antibiotic susceptibility testing technique.

  12. Set discrimination of quantum states

    International Nuclear Information System (INIS)

    Zhang Shengyu; Ying Mingsheng

    2002-01-01

    We introduce a notion of set discrimination, which is an interesting extension of quantum state discrimination. A state is secretly chosen from a number of quantum states, which are partitioned into some disjoint sets. A set discrimination is required to identify which set the given state belongs to. Several essential problems are addressed in this paper, including the condition of perfect set discrimination, unambiguous set discrimination, and in the latter case, the efficiency of the discrimination. This generalizes some important results on quantum state discrimination in the literature. A combination of state and set discrimination and the efficiency are also studied

  13. Sex Discrimination in Selecting Administrators.

    Science.gov (United States)

    Zirkel, Perry A.; Gluckman, Ivan B.

    1984-01-01

    Discusses recent sex discrimination cases by women seeking administrative positions. Points out that women plaintiffs alleging sex bias in such cases have a difficult time proving discrimination. (MD)

  14. Harassment, Bias, and Discrimination.

    Science.gov (United States)

    Welliver, Paul W.

    1995-01-01

    Discusses a new principle which has been added to the AECT (Association for Educational Communications and Technology) Code of Professional Ethics regarding discrimination, harassment, and bias. An example is presented which illustrates a violation of a professional colleague's rights. (LRW)

  15. Discrimination of consonance and dissonance in Java sparrows.

    Science.gov (United States)

    Watanabe, S; Uozumi, M; Tanaka, N

    2005-09-30

    Six adult Java sparrows were trained to discriminate between consonant and dissonant sounds consisting of three tones. In the consonance group, the perching response was reinforced when consonance was presented, but not when dissonance was presented. Both groups were given an inversion test, in which the first inversion of the chord was used as a stimulus. Four of six birds learned the discrimination and were given two tests. In the first test, novel consonances and novel dissonances were presented. All birds maintained the discrimination. When inverted consonances and dissonances were presented in the second test, the discriminative behavior was not well demonstrated. When novel dissonances consisting of tones with different intervals were presented in the third test, birds trained to perch for dissonance performed well, whereas those trained to perch for consonance did not. In summary, Java sparrows were able to discriminate between consonances and dissonances and demonstrated generalization to new combinations, they do not discriminate the same consonances and dissonances.

  16. Pigeons can discriminate "good" and "bad" paintings by children.

    Science.gov (United States)

    Watanabe, Shigeru

    2010-01-01

    Humans have the unique ability to create art, but non-human animals may be able to discriminate "good" art from "bad" art. In this study, I investigated whether pigeons could be trained to discriminate between paintings that had been judged by humans as either "bad" or "good". To do this, adult human observers first classified several children's paintings as either "good" (beautiful) or "bad" (ugly). Using operant conditioning procedures, pigeons were then reinforced for pecking at "good" paintings. After the pigeons learned the discrimination task, they were presented with novel pictures of both "good" and "bad" children's paintings to test whether they had successfully learned to discriminate between these two stimulus categories. The results showed that pigeons could discriminate novel "good" and "bad" paintings. Then, to determine which cues the subjects used for the discrimination, I conducted tests of the stimuli when the paintings were of reduced size or grayscale. In addition, I tested their ability to discriminate when the painting stimuli were mosaic and partial occluded. The pigeons maintained discrimination performance when the paintings were reduced in size. However, discrimination performance decreased when stimuli were presented as grayscale images or when a mosaic effect was applied to the original stimuli in order to disrupt spatial frequency. Thus, the pigeons used both color and pattern cues for their discrimination. The partial occlusion did not disrupt the discriminative behavior suggesting that the pigeons did not attend to particular parts, namely upper, lower, left or right half, of the paintings. These results suggest that the pigeons are capable of learning the concept of a stimulus class that humans name "good" pictures. The second experiment showed that pigeons learned to discriminate watercolor paintings from pastel paintings. The subjects showed generalization to novel paintings. Then, as the first experiment, size reduction test

  17. Gender discrimination and nursing: α literature review.

    Science.gov (United States)

    Kouta, Christiana; Kaite, Charis P

    2011-01-01

    This article aims to examine gender stereotypes in relation to men in nursing, discuss gender discrimination cases in nursing, and explore methods used for promoting equal educational opportunities during nursing studies. The literature review was based on related databases, such as CINAHL, Science Direct, MEDLINE, and EBSCO. Legal case studies are included in order to provide a more practical example of those barriers existing for men pursuing nursing, as well as statistical data concerning gender discrimination and male attrition to nursing schools in relation to those barriers. These strengthen the validity of the manuscript. Literature review showed that gender discrimination is still prevalent within nursing profession. Nursing faculty should prepare male nursing students to interact effectively with female clients as well. Role modeling the therapeutic relationship with clients is one strategy that may help male students. In general, the faculty should provide equal learning opportunities to nursing students. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Sex differences in discriminating between cues predicting threat and safety.

    Science.gov (United States)

    Day, Harriet L L; Reed, Molly M; Stevenson, Carl W

    2016-09-01

    Post-traumatic stress disorder (PTSD) is more prevalent in women than men. PTSD is characterized by overgeneralization of fear to innocuous stimuli and involves impaired inhibition of learned fear by cues that predict safety. While evidence indicates that learned fear inhibition through extinction differs in males and females, less is known about sex differences in fear discrimination and safety learning. Here we examined auditory fear discrimination in male and female rats. In Experiment 1A, rats underwent 1-3days of discrimination training consisting of one tone predicting threat (CS+; presented with footshock) and another tone predicting safety (CS-; presented alone). Females, but not males, discriminated between the CS+ and CS- after one day of training. After 2-3days of training, however, males discriminated whereas females generalized between the CS+ and CS-. In Experiment 1B, females showed enhanced anxiety-like behaviour and locomotor activity in the open field, although these results were unlikely to explain the sex differences in fear discrimination. In Experiment 2, we found no differences in shock sensitivity between males and females. In Experiment 3, males and females again discriminated and generalized, respectively, after three days of training. Moreover, fear generalization in females resulted from impaired safety learning, as shown by a retardation test. Whereas subsequent fear conditioning to the previous CS- retarded learning in males, females showed no such retardation. These results suggest that, while females show fear discrimination with limited training, they show fear generalization with extended training due to impaired safety learning. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  19. Price Discrimination and Market Power

    OpenAIRE

    Shane Carbonneau; Preston McAfee; Hugo Mialon; Sue Mialon

    2004-01-01

    If there is price discrimination, at least one of the prices is not equal to marginal cost. Therefore, if there is price discrimination, there must be market power. While this logic is sound, it has led many policymakers to believe that price discrimination and market power are positively correlated. We present a model where measured price discrimination can be low while market power is high, and price discrimination can be high while market power is low, thus demonstrating that there is no t...

  20. Drugs, discrimination and disability.

    Science.gov (United States)

    Gibson, Frances

    2009-12-01

    Whether addiction to prohibited drugs should be classified as a disability for the purposes of disability discrimination is a controversial question in Australia. The leading Australian case of Marsden v Human Rights Equal Opportunity Commission & Coffs Harbour & District Ex-Servicemen & Women's Memorial Club Ltd (HREOC, No H98/51, 30 August 1999); [2000] FCA 1619 concerned a disability discrimination complaint brought by Mr Marsden as a result of his treatment by the club. The case was brought as a public interest test case by the New South Wales Legal Aid Commission. Mr Marsden was on a methadone program at the time. The reasoning of the decision at the Federal Court opened the way for a finding that dependence on illegal drugs constituted a disability under disability discrimination legislation. The media reaction to the court's decision led to State and federal governments proposing legislation limiting legal protection from discrimination for people addicted to illegal drugs on the basis of their drug use. While the proposed federal legislation lapsed after objections from a coalition of medical, legal and other advocacy groups, the New South Wales legislation still provides that, in employment matters, it is not unlawful to discriminate against a person on the ground of disability if the disability relates to the person's addiction to a prohibited drug and the person is actually addicted to a prohibited drug at the time of the discrimination. The article details the sequence of events in the Marsden case, reflects on the role of public interest litigation in achieving social justice outcomes and suggests that Australia's recent ratification of the Convention on the Rights of Persons with Disabilities on 17 July 2008 should encourage legislators to review legislation which may have a discriminatory effect on people suffering from addictions.

  1. Disturbance by optimal discrimination

    Science.gov (United States)

    Kawakubo, Ryûitirô; Koike, Tatsuhiko

    2018-03-01

    We discuss the disturbance by measurements which unambiguously discriminate between given candidate states. We prove that such an optimal measurement necessarily changes distinguishable states indistinguishable when the inconclusive outcome is obtained. The result was previously shown by Chefles [Phys. Lett. A 239, 339 (1998), 10.1016/S0375-9601(98)00064-4] under restrictions on the class of quantum measurements and on the definition of optimality. Our theorems remove these restrictions and are also applicable to infinitely many candidate states. Combining with our previous results, one can obtain concrete mathematical conditions for the resulting states. The method may have a wide variety of applications in contexts other than state discrimination.

  2. Honeybees can discriminate between Monet and Picasso paintings.

    Science.gov (United States)

    Wu, Wen; Moreno, Antonio M; Tangen, Jason M; Reinhard, Judith

    2013-01-01

    Honeybees (Apis mellifera) have remarkable visual learning and discrimination abilities that extend beyond learning simple colours, shapes or patterns. They can discriminate landscape scenes, types of flowers, and even human faces. This suggests that in spite of their small brain, honeybees have a highly developed capacity for processing complex visual information, comparable in many respects to vertebrates. Here, we investigated whether this capacity extends to complex images that humans distinguish on the basis of artistic style: Impressionist paintings by Monet and Cubist paintings by Picasso. We show that honeybees learned to simultaneously discriminate between five different Monet and Picasso paintings, and that they do not rely on luminance, colour, or spatial frequency information for discrimination. When presented with novel paintings of the same style, the bees even demonstrated some ability to generalize. This suggests that honeybees are able to discriminate Monet paintings from Picasso ones by extracting and learning the characteristic visual information inherent in each painting style. Our study further suggests that discrimination of artistic styles is not a higher cognitive function that is unique to humans, but simply due to the capacity of animals-from insects to humans-to extract and categorize the visual characteristics of complex images.

  3. Immunological self, nonself discrimination

    DEFF Research Database (Denmark)

    Guillet, J G; Lai, M Z; Briner, T J

    1987-01-01

    The ability of immunodominant peptides derived from several antigen systems to compete with each other for T cell activation was studied. Only peptides restricted by a given transplantation antigen are mutually competitive. There is a correlation between haplotype restriction, ability to bind to ...... that provides a basis for explaining self, nonself discrimination as well as alloreactivity....

  4. Discriminative Shape Alignment

    DEFF Research Database (Denmark)

    Loog, M.; de Bruijne, M.

    2009-01-01

    , not taking into account that eventually the shapes are to be assigned to two or more different classes. This work introduces a discriminative variation to well-known Procrustes alignment and demonstrates its benefit over this classical method in shape classification tasks. The focus is on two...

  5. Homosexual Discrimination in Employment

    Science.gov (United States)

    Siniscalco, Gary R.

    1976-01-01

    Recent developments in homosexual activism regarding employment problems in both the public and private sector are analyzed. Focus is on the law governing private employment, where homosexuals are afforded the least legal protection against discrimination. Available from: the University of Santa Clara, Santa Clara, California 95053. (LBH)

  6. Discrimination? - Exhibition of posters

    OpenAIRE

    Jakimovska, Jana

    2017-01-01

    Participation in the exhibition with the students form the Art Academy. The exhibition consisted of 15 posters tackling the subjects of hate speech and discrimination. The exhibition happened thanks to the invitation of the Faculty of Law at UGD, and it was a part of a larger event of launching books on the aforementioned subjects.

  7. "Man" and Sexual Discrimination.

    Science.gov (United States)

    Coppin, Mary

    1981-01-01

    Comments on the linguistic impact of the Canadian Human Rights Act, which forbids discrimination on the basis qf sex, examining its effects on common English usages of "man." After illustrating the problems posed by government guidelines on job titles, addresses the ideological and socioeconomic implications of the "man" issue.…

  8. Education and Gender Discrimination

    Science.gov (United States)

    Sumi, V. S.

    2012-01-01

    This paper discusses the status of women education in present education system and some measures to overcome the lags existing. Discrimination against girls and women in the developing world is a devastating reality. It results in millions of individual tragedies, which add up to lost potential for entire countries. Gender bias in education is an…

  9. Airborne particulate discriminator

    Science.gov (United States)

    Creek, Kathryn Louise [San Diego, CA; Castro, Alonso [Santa Fe, NM; Gray, Perry Clayton [Los Alamos, NM

    2009-08-11

    A method and apparatus for rapid and accurate detection and discrimination of biological, radiological, and chemical particles in air. A suspect aerosol of the target particulates is treated with a taggant aerosol of ultrafine particulates. Coagulation of the taggant and target particles causes a change in fluorescent properties of the cloud, providing an indication of the presence of the target.

  10. Housing discrimination 101.

    Science.gov (United States)

    Massey, D

    2000-01-01

    To examine the hypothesis that phone-based discrimination exists, an undergraduate course was conducted at the University of Pennsylvania. It was noted that racial housing audits were designed in such a way that teams of White and Black auditors were assigned similar identities and characteristics. To this effect, systematic differences in treatment were taken to reflect racial discrimination. The course, ¿Research Design: Measurement of Discrimination,¿ was carried out as a response to the pressure to involve undergraduates in research. A racially diverse group of students registered, among them speakers of Black English Vernacular, Black Accented English, and White Middle Class English. A total of 79 rental units advertised in newspapers and rental guides were audited by the class. Overall, results of the study suggest that telephone audits constitute a potentially cheap, easy, and efficient way of measuring and studying processes of racial discrimination in urban housing markets. Compared with Whites, African Americans were less likely to be told of a unit's availability, more likely to speak to a rental agent, to pay an application fee, and to have credit mentioned as an issue. In addition, these racial effects interacted with and were exacerbated by gender class.

  11. Aptitude Tests and Discrimination

    Science.gov (United States)

    Coupland, D. E.

    1970-01-01

    Explains why in the United States the feeling is increasing that much of the aptitude testing now being done discriminates against minority group members seeking employment. Skeptical of eliminating the discriminatory aspects of testing, the article raises the question of eliminating testing itself. (DM)

  12. Examining Workplace Discrimination in a Discrimination-Free Environment

    OpenAIRE

    Braxton, Shawn Lamont

    2010-01-01

    Examining Workplace Discrimination in a Discrimination-Free Environment Shawn L. Braxton Abstract The purpose of this study is to explore how racial and gender discrimination is reproduced in concrete workplace settings even when anti-discrimination policies are present, and to understand the various reactions utilized by those who commonly experience it. I have selected a particular medical center, henceforth referred to by a pseudonym, â The Bliley Medical Centerâ as my case ...

  13. Conditioning procedure and color discrimination in the honeybee Apis mellifera

    Science.gov (United States)

    Giurfa, Martin

    We studied the influence of the conditioning procedure on color discrimination by free-flying honeybees. We asked whether absolute and differential conditioning result in different discrimination capabilities for the same pairs of colored targets. In absolute conditioning, bees were rewarded on a single color; in differential conditioning, bees were rewarded on the same color but an alternative, non-rewarding, similar color was also visible. In both conditioning procedures, bees learned their respective task and could also discriminate the training stimulus from a novel stimulus that was perceptually different from the trained one. Discrimination between perceptually closer stimuli was possible after differential conditioning but not after absolute conditioning. Differences in attention inculcated by these training procedures may underlie the different discrimination performances of the bees.

  14. The Case for Positive Discrimination

    Science.gov (United States)

    Miller, S. M.

    1973-01-01

    Discusses both three basic strategies, preferences, allocational priorities, and incentives--and four principles of positive discrimination--compensation and rectification, appropriate meritocratic criteria, the development of the discriminated, and fairness. (JM)

  15. The Struggle against Sex Discrimination.

    Science.gov (United States)

    Williamson, Jane

    1982-01-01

    Provides overview of laws, policies, and regulations available to women to secure their job rights when faced with sex discrimination. Equal pay, sexual harassment, pregnancy discrimination, and affirmative action are discussed, noting procedures involved in filing a complaint. (EJS)

  16. Fast timing discriminator

    International Nuclear Information System (INIS)

    Lo, C.C.

    1977-01-01

    The processing of pulses with very fast risetimes for timing purposes involves many problems because of the large equivalent bandwidths involved. For pulses with risetimes in the 150 ps range (and full widths at half maximum (FWHM) of 400 ps) bandwidths in excess of 1GHz are required. Furthermore, these very narrow pulses with current amplitudes as small as 1 mA carry very small charges ( -12 coulomb), therefore, requiring very sensitive trigger circuits. The difficulty increases when timing characteristics in the picosecond range are sought especially when a wide input signal amplitude range causes a time-walk problem. The fast timing discriminator described has a time-walk of approximately +-75 ps over the input signal range from 80 mV to 3V. A schematic of the discriminator is included, and operation and performance are discussed

  17. Learning Dictionaries of Discriminative Image Patches

    DEFF Research Database (Denmark)

    Dahl, Anders Lindbjerg; Larsen, Rasmus

    2011-01-01

    Remarkable results have been obtained using image models based on image patches, for example sparse generative models for image inpainting, noise reduction and superresolution, sparse texture segmentation or texton models. In this paper we propose a powerful and yet simple approach for segmentation...

  18. Locality-Constrained Discriminative Learning and Coding

    Science.gov (United States)

    2015-06-12

    methods, i.e. FDDL [27], DL- RD [16], D2L2R2 [12] and DPL [7]. In each experiment, we keep all the steps the same as that of the baselines except for the...percentage of corruption increases our algorithm perform- s the best constantly. The performance of FDDL as well as DPL , LRC and LDA drops rapidly, by contrast...different number of training samples per class. Training images DPL [7] D2L2R2 [12] DLRD [16] FDDL [27] LRC [18] LDA [2] Ours 5 75.17±1.86 75.96±1.20 76.17

  19. Plant Leaf Recognition through Local Discriminative Tangent Space Alignment

    Directory of Open Access Journals (Sweden)

    Chuanlei Zhang

    2016-01-01

    Full Text Available Manifold learning based dimensionality reduction algorithms have been payed much attention in plant leaf recognition as the algorithms can select a subset of effective and efficient discriminative features in the leaf images. In this paper, a dimensionality reduction method based on local discriminative tangent space alignment (LDTSA is introduced for plant leaf recognition based on leaf images. The proposed method can embrace part optimization and whole alignment and encapsulate the geometric and discriminative information into a local patch. The experiments on two plant leaf databases, ICL and Swedish plant leaf datasets, demonstrate the effectiveness and feasibility of the proposed method.

  20. Stable locality sensitive discriminant analysis for image recognition.

    Science.gov (United States)

    Gao, Quanxue; Liu, Jingjing; Cui, Kai; Zhang, Hailin; Wang, Xiaogang

    2014-06-01

    Locality Sensitive Discriminant Analysis (LSDA) is one of the prevalent discriminant approaches based on manifold learning for dimensionality reduction. However, LSDA ignores the intra-class variation that characterizes the diversity of data, resulting in unstableness of the intra-class geometrical structure representation and not good enough performance of the algorithm. In this paper, a novel approach is proposed, namely stable locality sensitive discriminant analysis (SLSDA), for dimensionality reduction. SLSDA constructs an adjacency graph to model the diversity of data and then integrates it in the objective function of LSDA. Experimental results in five databases show the effectiveness of the proposed approach. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Employee Discrimination against Female Executives

    OpenAIRE

    Kodama, Naomi; Odaki, Kazuhiko

    2013-01-01

    The theory of employee discrimination gives a possible explanation for the scarcity of female executive officers. This paper tests the employee discrimination hypothesis by measuring the wage premium received by employees working with female executives against their tastes for discrimination. Using a fixed effects analysis of establishment-level panel data on Japanese employees, we separate the discrimination premiums that would otherwise cause a bias from the establishment-level unobserved p...

  2. [Comment on] Statistical discrimination

    Science.gov (United States)

    Chinn, Douglas

    In the December 8, 1981, issue of Eos, a news item reported the conclusion of a National Research Council study that sexual discrimination against women with Ph.D.'s exists in the field of geophysics. Basically, the item reported that even when allowances are made for motherhood the percentage of female Ph.D.'s holding high university and corporate positions is significantly lower than the percentage of male Ph.D.'s holding the same types of positions. The sexual discrimination conclusion, based only on these statistics, assumes that there are no basic psychological differences between men and women that might cause different populations in the employment group studied. Therefore, the reasoning goes, after taking into account possible effects from differences related to anatomy, such as women stopping their careers in order to bear and raise children, the statistical distributions of positions held by male and female Ph.D.'s ought to be very similar to one another. Any significant differences between the distributions must be caused primarily by sexual discrimination.

  3. Workplace discrimination and cancer.

    Science.gov (United States)

    McKenna, Maureen A; Fabian, Ellen; Hurley, Jessica E; McMahon, Brian T; West, Steven L

    2007-01-01

    Data from the Equal Employment Opportunity Commission (EEOC) Integrated Mission System database were analyzed with specific reference to allegations of workplace discrimination filed by individuals with cancer under ADA Title One. These 6,832 allegations, filed between July 27, 1992 and September 30, 2003, were compared to 167,798 allegations from a general disability population on the following dimensions: type of workplace discrimination; demographic characteristics of the charging parties (CPs); the industry designation, location, and size of employers; and the outcome or resolution of EEOC investigations. Results showed allegations derived from CPs with cancer were more likely than those in the general disability population to include issues involving discharge, terms and conditions of employment, lay-off, wages, and demotion. Compared to the general disability group, CPs with cancer were more likely to be female, older, and White. Allegations derived from CPs with cancer were also more likely to be filed against smaller employers (15-100 workers) or those in service industries. Finally, the resolution of allegations by CPs with cancer were more likely to be meritorious than those filed from the general disability population; that is, actual discrimination is more likely to have occurred.

  4. Sex Discrimination? The XYZ Affair.

    Science.gov (United States)

    Hoffmann, Carl; Reed, John Shelton

    1981-01-01

    Describes an investigation of sex discrimination at a large American corporation. The investigation found that although fewer women than men were promoted, this was due to greater interest in promotion expressed by men, rather than to discrimination by the company. Argues against criteria applied by federal agencies to prove discrimination. (GC)

  5. Price Discrimination: A Classroom Experiment

    Science.gov (United States)

    Aguiló, Paula; Sard, Maria; Tugores, Maria

    2016-01-01

    In this article, the authors describe a classroom experiment aimed at familiarizing students with different types of price discrimination (first-, second-, and third-degree price discrimination). During the experiment, the students were asked to decide what tariffs to set as monopolists for each of the price discrimination scenarios under…

  6. Transgender Discrimination and the Law

    Science.gov (United States)

    Trotter, Richard

    2010-01-01

    An emerging area of law is developing regarding sex/gender identity discrimination, also referred to as transgender discrimination, as distinguished from discrimination based on sexual orientation. A transgendered individual is defined as "a person who has a gender-identity disorder which is a persistent discomfort about one?s assigned sex or…

  7. Price Discrimination: Lessons for Consumers.

    Science.gov (United States)

    Maynes, E. Scott

    1990-01-01

    Explains price and product discrimination, showing how intelligent consumers can achieve increased purchasing power of their income and discusses how consumer educators can explain this discrimination. Evaluates the pros and cons of price/product discrimination from the social viewpoint. (Author/JOW)

  8. Motion direction discrimination training reduces perceived motion repulsion.

    Science.gov (United States)

    Jia, Ke; Li, Sheng

    2017-04-01

    Participants often exaggerate the perceived angular separation between two simultaneously presented motion stimuli, which is referred to as motion repulsion. The overestimation helps participants differentiate between the two superimposed motion directions, yet it causes the impairment of direction perception. Since direction perception can be refined through perceptual training, we here attempted to investigate whether the training of a direction discrimination task changes the amount of motion repulsion. Our results showed a direction-specific learning effect, which was accompanied by a reduced amount of motion repulsion both for the trained and the untrained directions. The reduction of the motion repulsion disappeared when the participants were trained on a luminance discrimination task (control experiment 1) or a speed discrimination task (control experiment 2), ruling out any possible interpretation in terms of adaptation or training-induced attentional bias. Furthermore, training with a direction discrimination task along a direction 150° away from both directions in the transparent stimulus (control experiment 3) also had little effect on the amount of motion repulsion, ruling out the contribution of task learning. The changed motion repulsion observed in the main experiment was consistent with the prediction of the recurrent model of perceptual learning. Therefore, our findings demonstrate that training in direction discrimination can benefit the precise direction perception of the transparent stimulus and provide new evidence for the recurrent model of perceptual learning.

  9. Olfactory repeated discrimination reversal in rats: effects of chlordiazepoxide, dizocilpine, and morphine.

    Science.gov (United States)

    Galizio, Mark; Miller, Laurence; Ferguson, Adam; McKinney, Patrick; Pitts, Raymond C

    2006-10-01

    Effects of a benzodiazepine (chlordiazepoxide), an N-methyl-D-aspartate receptor antagonist (dizocilpine), and an opiate agonist (morphine) were studied with a procedure designed to assess effects of drugs and other manipulations on nonspatial learning in rats. In each session, rats were exposed to 2 different 2-choice odor-discrimination problems with food reinforcement for correct responses. One problem (performance discrimination) remained the same throughout the study. That is, 1 odor was always correct (S+) and the other was never correct (S-). For the other problem (reversal discrimination), stimuli changed every session. Six different odors were used to program the reversal discrimination; on any given session, S+ was a stimulus that had served as S- the last time it had appeared, S- was a stimulus that had been S+ on its last appearance. Thus, in each session, learning a discrimination reversal could be studied along with the performance of a comparable, but previously learned, discrimination. Chlordiazepoxide interfered with reversal learning at doses that had no effect on the performance discrimination. Morphine and dizocilpine also impaired reversal learning but only at doses that also affected performance of the well-learned performance discrimination.

  10. Low power constant fraction discriminator

    International Nuclear Information System (INIS)

    Krishnan, Shanti; Raut, S.M.; Mukhopadhyay, P.K.

    2001-01-01

    This paper describes the design of a low power ultrafast constant fraction discriminator, which significantly reduces the power consumption. A conventional fast discriminator consumes about 1250 MW of power whereas this low power version consumes about 440 MW. In a multi detector system, where the number of discriminators is very large, reduction of power is of utmost importance. This low power discriminator is being designed for GRACE (Gamma Ray Atmospheric Cerenkov Experiments) telescope where 1000 channels of discriminators are required. A novel method of decreasing power consumption has been described. (author)

  11. The effect of stimulus height on visual discrimination in horses

    OpenAIRE

    Hall, CA; Cassaday, HJ; Derrington, AM

    2003-01-01

    This study investigated the effect of stimulus height on the ability of horses to learn a simple visual discrimination task. Eight horses were trained to perform a two-choice black/white discrimination with stimuli presented at one of two heights: at ground level or at a height of 70cm from the ground. The height at which the stimuli were presented was alternated from one session to the next. All trials within a single session were presented at the same height. The criterion for learning was ...

  12. Object recognition with hierarchical discriminant saliency networks

    Directory of Open Access Journals (Sweden)

    Sunhyoung eHan

    2014-09-01

    Full Text Available The benefits of integrating attention and object recognition are investigated. While attention is frequently modeled as pre-processor for recognition, we investigate the hypothesis that attention is an intrinsic component of recognition and vice-versa. This hypothesis is tested with a recognitionmodel, the hierarchical discriminant saliency network (HDSN, whose layers are top-down saliency detectors, tuned for a visual class according to the principles of discriminant saliency. The HDSN has two possible implementations. In a biologically plausible implementation, all layers comply with the standard neurophysiological model of visual cortex, with sub-layers of simple and complex units that implement a combination of filtering, divisive normalization, pooling, and non-linearities. In a neuralnetwork implementation, all layers are convolutional and implement acombination of filtering, rectification, and pooling. The rectificationis performed with a parametric extension of the now popular rectified linearunits (ReLUs, whose parameters can be tuned for the detection of targetobject classes. This enables a number of functional enhancementsover neural network models that lack a connection to saliency, including optimal feature denoising mechanisms for recognition, modulation ofsaliency responses by the discriminant power of the underlying features,and the ability to detect both feature presence and absence.In either implementation, each layer has a precise statistical interpretation, and all parameters are tuned by statistical learning. Each saliency detection layer learns more discriminant saliency templates than its predecessors and higher layers have larger pooling fields. This enables the HDSN to simultaneously achieve high selectivity totarget object classes and invariance. The resulting performance demonstrates benefits for all the functional enhancements of the HDSN.

  13. Learning in Mental Retardation: A Comprehensive Bibliography.

    Science.gov (United States)

    Gardner, James M.; And Others

    The bibliography on learning in mentally handicapped persons is divided into the following topic categories: applied behavior change, classical conditioning, discrimination, generalization, motor learning, reinforcement, verbal learning, and miscellaneous. An author index is included. (KW)

  14. Haptic Discrimination of Distance

    Science.gov (United States)

    van Beek, Femke E.; Bergmann Tiest, Wouter M.; Kappers, Astrid M. L.

    2014-01-01

    While quite some research has focussed on the accuracy of haptic perception of distance, information on the precision of haptic perception of distance is still scarce, particularly regarding distances perceived by making arm movements. In this study, eight conditions were measured to answer four main questions, which are: what is the influence of reference distance, movement axis, perceptual mode (active or passive) and stimulus type on the precision of this kind of distance perception? A discrimination experiment was performed with twelve participants. The participants were presented with two distances, using either a haptic device or a real stimulus. Participants compared the distances by moving their hand from a start to an end position. They were then asked to judge which of the distances was the longer, from which the discrimination threshold was determined for each participant and condition. The precision was influenced by reference distance. No effect of movement axis was found. The precision was higher for active than for passive movements and it was a bit lower for real stimuli than for rendered stimuli, but it was not affected by adding cutaneous information. Overall, the Weber fraction for the active perception of a distance of 25 or 35 cm was about 11% for all cardinal axes. The recorded position data suggest that participants, in order to be able to judge which distance was the longer, tried to produce similar speed profiles in both movements. This knowledge could be useful in the design of haptic devices. PMID:25116638

  15. Haptic discrimination of distance.

    Directory of Open Access Journals (Sweden)

    Femke E van Beek

    Full Text Available While quite some research has focussed on the accuracy of haptic perception of distance, information on the precision of haptic perception of distance is still scarce, particularly regarding distances perceived by making arm movements. In this study, eight conditions were measured to answer four main questions, which are: what is the influence of reference distance, movement axis, perceptual mode (active or passive and stimulus type on the precision of this kind of distance perception? A discrimination experiment was performed with twelve participants. The participants were presented with two distances, using either a haptic device or a real stimulus. Participants compared the distances by moving their hand from a start to an end position. They were then asked to judge which of the distances was the longer, from which the discrimination threshold was determined for each participant and condition. The precision was influenced by reference distance. No effect of movement axis was found. The precision was higher for active than for passive movements and it was a bit lower for real stimuli than for rendered stimuli, but it was not affected by adding cutaneous information. Overall, the Weber fraction for the active perception of a distance of 25 or 35 cm was about 11% for all cardinal axes. The recorded position data suggest that participants, in order to be able to judge which distance was the longer, tried to produce similar speed profiles in both movements. This knowledge could be useful in the design of haptic devices.

  16. Discriminative sparse coding on multi-manifolds

    KAUST Repository

    Wang, J.J.-Y.

    2013-09-26

    Sparse coding has been popularly used as an effective data representation method in various applications, such as computer vision, medical imaging and bioinformatics. However, the conventional sparse coding algorithms and their manifold-regularized variants (graph sparse coding and Laplacian sparse coding), learn codebooks and codes in an unsupervised manner and neglect class information that is available in the training set. To address this problem, we propose a novel discriminative sparse coding method based on multi-manifolds, that learns discriminative class-conditioned codebooks and sparse codes from both data feature spaces and class labels. First, the entire training set is partitioned into multiple manifolds according to the class labels. Then, we formulate the sparse coding as a manifold-manifold matching problem and learn class-conditioned codebooks and codes to maximize the manifold margins of different classes. Lastly, we present a data sample-manifold matching-based strategy to classify the unlabeled data samples. Experimental results on somatic mutations identification and breast tumor classification based on ultrasonic images demonstrate the efficacy of the proposed data representation and classification approach. 2013 The Authors. All rights reserved.

  17. Discriminative Elastic-Net Regularized Linear Regression.

    Science.gov (United States)

    Zhang, Zheng; Lai, Zhihui; Xu, Yong; Shao, Ling; Wu, Jian; Xie, Guo-Sen

    2017-03-01

    In this paper, we aim at learning compact and discriminative linear regression models. Linear regression has been widely used in different problems. However, most of the existing linear regression methods exploit the conventional zero-one matrix as the regression targets, which greatly narrows the flexibility of the regression model. Another major limitation of these methods is that the learned projection matrix fails to precisely project the image features to the target space due to their weak discriminative capability. To this end, we present an elastic-net regularized linear regression (ENLR) framework, and develop two robust linear regression models which possess the following special characteristics. First, our methods exploit two particular strategies to enlarge the margins of different classes by relaxing the strict binary targets into a more feasible variable matrix. Second, a robust elastic-net regularization of singular values is introduced to enhance the compactness and effectiveness of the learned projection matrix. Third, the resulting optimization problem of ENLR has a closed-form solution in each iteration, which can be solved efficiently. Finally, rather than directly exploiting the projection matrix for recognition, our methods employ the transformed features as the new discriminate representations to make final image classification. Compared with the traditional linear regression model and some of its variants, our method is much more accurate in image classification. Extensive experiments conducted on publicly available data sets well demonstrate that the proposed framework can outperform the state-of-the-art methods. The MATLAB codes of our methods can be available at http://www.yongxu.org/lunwen.html.

  18. Discrimination against Muslim American adolescents.

    Science.gov (United States)

    Aroian, Karen J

    2012-06-01

    Although there is ample evidence of discrimination toward Muslim Americans in general, there is limited information specific to Muslim American adolescents. The few existing studies specific to this age group suggest that Muslim American adolescents encounter much discrimination from teachers, school administrators, and classmates. This descriptive qualitative study complements the few existing studies on Muslim American adolescents by obtaining in-depth description of the discrimination they encounter. The sample was 14 Muslim American adolescents who participated in one of two gender-specific focus groups about their discrimination experiences. Findings identified school settings as rife with discrimination toward Muslims, portrayed Muslim girls as at risk for harassment by strangers in public places, and illustrated how Muslim youth cope with discrimination. The study findings sensitize school nurses to the nature of the problem and provide direction for intervention.

  19. Institutional discrimination in Paediatric hospitals

    Directory of Open Access Journals (Sweden)

    I. A. ATUDOREI

    2012-01-01

    Full Text Available Social discrimination stands for one of the phenomena that social policies attempt to counteract by legislation, with a view to impeding its effects. Nevertheless, at institutional level, the decisions perpetuate and encourage discrimination, being practically a norm in an abnormal situation. Abnormality is represented by a series of deficiencies falling within the scope of perverse effects. Having analyzed institutional policies in the field of child health, we have identified a series of issues that fall under social discrimination. The paper submits the reasons for institutional discrimination in paediatric hospitals. The purpose of the research is to identify the discriminated persons and to report the repercussions of institutional discrimination at social level.

  20. Melody Track Selection Using Discriminative Language Model

    Science.gov (United States)

    Wu, Xiao; Li, Ming; Suo, Hongbin; Yan, Yonghong

    In this letter we focus on the task of selecting the melody track from a polyphonic MIDI file. Based on the intuition that music and language are similar in many aspects, we solve the selection problem by introducing an n-gram language model to learn the melody co-occurrence patterns in a statistical manner and determine the melodic degree of a given MIDI track. Furthermore, we propose the idea of using background model and posterior probability criteria to make modeling more discriminative. In the evaluation, the achieved 81.6% correct rate indicates the feasibility of our approach.

  1. Discriminative and reinforcing stimulus properties of music for rats.

    Science.gov (United States)

    Otsuka, Y; Yanagi, J; Watanabe, S

    2009-02-01

    We trained rats to discriminate music by Bach from that by Stravinsky using operant conditioning. The rats successfully learned the discrimination and transferred their discrimination to novel music by the same artists. Then, we trained rats on concurrent-chain schedule in which the terminal links were associated with different music, Bach or Stravinsky. The rats did not show strong preference for either style of music, although one subject showed a preference for Bach and another subject preferred Stravinsky. Finally, we examined the validity of the concurrent-chain procedure as a method of preference measurement with conspecific vocalization evoked by an aversive experience. Most of the rats preferred white noise to the conspecific vocalization. Therefore, music has a discriminative stimulus property but not a clear reinforcing property for rats.

  2. A Web-Server of Cell Type Discrimination System

    Directory of Open Access Journals (Sweden)

    Anyou Wang

    2014-01-01

    Full Text Available Discriminating cell types is a daily request for stem cell biologists. However, there is not a user-friendly system available to date for public users to discriminate the common cell types, embryonic stem cells (ESCs, induced pluripotent stem cells (iPSCs, and somatic cells (SCs. Here, we develop WCTDS, a web-server of cell type discrimination system, to discriminate the three cell types and their subtypes like fetal versus adult SCs. WCTDS is developed as a top layer application of our recent publication regarding cell type discriminations, which employs DNA-methylation as biomarkers and machine learning models to discriminate cell types. Implemented by Django, Python, R, and Linux shell programming, run under Linux-Apache web server, and communicated through MySQL, WCTDS provides a friendly framework to efficiently receive the user input and to run mathematical models for analyzing data and then to present results to users. This framework is flexible and easy to be expended for other applications. Therefore, WCTDS works as a user-friendly framework to discriminate cell types and subtypes and it can also be expended to detect other cell types like cancer cells.

  3. A web-server of cell type discrimination system.

    Science.gov (United States)

    Wang, Anyou; Zhong, Yan; Wang, Yanhua; He, Qianchuan

    2014-01-01

    Discriminating cell types is a daily request for stem cell biologists. However, there is not a user-friendly system available to date for public users to discriminate the common cell types, embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and somatic cells (SCs). Here, we develop WCTDS, a web-server of cell type discrimination system, to discriminate the three cell types and their subtypes like fetal versus adult SCs. WCTDS is developed as a top layer application of our recent publication regarding cell type discriminations, which employs DNA-methylation as biomarkers and machine learning models to discriminate cell types. Implemented by Django, Python, R, and Linux shell programming, run under Linux-Apache web server, and communicated through MySQL, WCTDS provides a friendly framework to efficiently receive the user input and to run mathematical models for analyzing data and then to present results to users. This framework is flexible and easy to be expended for other applications. Therefore, WCTDS works as a user-friendly framework to discriminate cell types and subtypes and it can also be expended to detect other cell types like cancer cells.

  4. Genetic discrimination: international perspectives.

    Science.gov (United States)

    Otlowski, M; Taylor, S; Bombard, Y

    2012-01-01

    Genetic discrimination (GD) is a complex, multifaceted ethical, psychosocial, and legal phenomenon. It is defined as the differential treatment of asymptomatic individuals or their relatives on the basis of their real or assumed genetic characteristics. This article presents an overview of GD within the contemporary international context. It describes the concept of GD and its contextual features, reviews research evidence regarding people's experiences of GD and the impact of GD within a range of domains, and provides an overview of legal and policy responses to GD that have emerged globally. We argue that GD is a significant and internationally established phenomenon that requires multilevel responses to ensure social justice and equitable outcomes for all citizens. Future research should monitor GD and its impacts within the community as well as institutions and should evaluate the effectiveness of legislative, policy, community education, and systemic responses.

  5. Manifold Partition Discriminant Analysis.

    Science.gov (United States)

    Yang Zhou; Shiliang Sun

    2017-04-01

    We propose a novel algorithm for supervised dimensionality reduction named manifold partition discriminant analysis (MPDA). It aims to find a linear embedding space where the within-class similarity is achieved along the direction that is consistent with the local variation of the data manifold, while nearby data belonging to different classes are well separated. By partitioning the data manifold into a number of linear subspaces and utilizing the first-order Taylor expansion, MPDA explicitly parameterizes the connections of tangent spaces and represents the data manifold in a piecewise manner. While graph Laplacian methods capture only the pairwise interaction between data points, our method captures both pairwise and higher order interactions (using regional consistency) between data points. This manifold representation can help to improve the measure of within-class similarity, which further leads to improved performance of dimensionality reduction. Experimental results on multiple real-world data sets demonstrate the effectiveness of the proposed method.

  6. Weight discrimination and bullying.

    Science.gov (United States)

    Puhl, Rebecca M; King, Kelly M

    2013-04-01

    Despite significant attention to the medical impacts of obesity, often ignored are the negative outcomes that obese children and adults experience as a result of stigma, bias, and discrimination. Obese individuals are frequently stigmatized because of their weight in many domains of daily life. Research spanning several decades has documented consistent weight bias and stigmatization in employment, health care, schools, the media, and interpersonal relationships. For overweight and obese youth, weight stigmatization translates into pervasive victimization, teasing, and bullying. Multiple adverse outcomes are associated with exposure to weight stigmatization, including depression, anxiety, low self-esteem, body dissatisfaction, suicidal ideation, poor academic performance, lower physical activity, maladaptive eating behaviors, and avoidance of health care. This review summarizes the nature and extent of weight stigmatization against overweight and obese individuals, as well as the resulting consequences that these experiences create for social, psychological, and physical health for children and adults who are targeted. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Digital pulse shape discrimination

    International Nuclear Information System (INIS)

    Miller, L. F.; Preston, J.; Pozzi, S.; Flaska, M.; Neal, J.

    2007-01-01

    Pulse-shape discrimination (PSD) has been utilised for about 40 years as a method to obtain estimates for dose in mixed neutron and photon fields. Digitizers that operate close to GHz are currently available at a reasonable cost, and they can be used to directly sample signals from photomultiplier tubes. This permits one to perform digital PSD rather than the traditional, and well-established, analogous techniques. One issue that complicates PSD for neutrons in mixed fields is that the light output characteristics of typical scintillators available for PSD, such as BC501A, vary as a function of energy deposited in the detector. This behaviour is more easily accommodated with digital processing of signals than with analogous signal processing. Results illustrate the effectiveness of digital PSD. (authors)

  8. Perceived discrimination: why applicants and employees expect and perceive discrimination

    NARCIS (Netherlands)

    Abu Ghazaleh, N.

    2012-01-01

    In this dissertation we have investigated perceptions of discrimination. We have shown discrimination exists in the eyes of applicants and employees and especially when from an ethnic minority group. There are psychological variables that influence these perceptions differently for minority and

  9. Perceived weight discrimination and obesity.

    Directory of Open Access Journals (Sweden)

    Angelina R Sutin

    Full Text Available Weight discrimination is prevalent in American society. Although associated consistently with psychological and economic outcomes, less is known about whether weight discrimination is associated with longitudinal changes in obesity. The objectives of this research are (1 to test whether weight discrimination is associated with risk of becoming obese (Body Mass Index≥30; BMI by follow-up among those not obese at baseline, and (2 to test whether weight discrimination is associated with risk of remaining obese at follow-up among those already obese at baseline. Participants were drawn from the Health and Retirement Study, a nationally representative longitudinal survey of community-dwelling US residents. A total of 6,157 participants (58.6% female completed the discrimination measure and had weight and height available from the 2006 and 2010 assessments. Participants who experienced weight discrimination were approximately 2.5 times more likely to become obese by follow-up (OR = 2.54, 95% CI = 1.58-4.08 and participants who were obese at baseline were three times more likely to remain obese at follow up (OR = 3.20, 95% CI = 2.06-4.97 than those who had not experienced such discrimination. These effects held when controlling for demographic factors (age, sex, ethnicity, education and when baseline BMI was included as a covariate. These effects were also specific to weight discrimination; other forms of discrimination (e.g., sex, race were unrelated to risk of obesity at follow-up. The present research demonstrates that, in addition to poorer mental health outcomes, weight discrimination has implications for obesity. Rather than motivating individuals to lose weight, weight discrimination increases risk for obesity.

  10. Perceived weight discrimination and obesity.

    Science.gov (United States)

    Sutin, Angelina R; Terracciano, Antonio

    2013-01-01

    Weight discrimination is prevalent in American society. Although associated consistently with psychological and economic outcomes, less is known about whether weight discrimination is associated with longitudinal changes in obesity. The objectives of this research are (1) to test whether weight discrimination is associated with risk of becoming obese (Body Mass Index≥30; BMI) by follow-up among those not obese at baseline, and (2) to test whether weight discrimination is associated with risk of remaining obese at follow-up among those already obese at baseline. Participants were drawn from the Health and Retirement Study, a nationally representative longitudinal survey of community-dwelling US residents. A total of 6,157 participants (58.6% female) completed the discrimination measure and had weight and height available from the 2006 and 2010 assessments. Participants who experienced weight discrimination were approximately 2.5 times more likely to become obese by follow-up (OR = 2.54, 95% CI = 1.58-4.08) and participants who were obese at baseline were three times more likely to remain obese at follow up (OR = 3.20, 95% CI = 2.06-4.97) than those who had not experienced such discrimination. These effects held when controlling for demographic factors (age, sex, ethnicity, education) and when baseline BMI was included as a covariate. These effects were also specific to weight discrimination; other forms of discrimination (e.g., sex, race) were unrelated to risk of obesity at follow-up. The present research demonstrates that, in addition to poorer mental health outcomes, weight discrimination has implications for obesity. Rather than motivating individuals to lose weight, weight discrimination increases risk for obesity.

  11. Perceived discrimination in the Netherlands

    NARCIS (Netherlands)

    Iris Andriessen; Henk Fernee; Karin Wittebrood

    2014-01-01

    Only available in electronic version There is no systematic structure in the Netherlands for mapping out the discrimination experiences of different groups in different areas of society. As in many other countries, discrimination studies in the Netherlands mostly focus on the experiences

  12. Discrimination against Muslim American Adolescents

    Science.gov (United States)

    Aroian, Karen J.

    2012-01-01

    Although there is ample evidence of discrimination toward Muslim Americans in general, there is limited information specific to Muslim American adolescents. The few existing studies specific to this age group suggest that Muslim American adolescents encounter much discrimination from teachers, school administrators, and classmates. This…

  13. THE HIGH COST OF DISCRIMINATION.

    Science.gov (United States)

    ROPER, ELMO

    ON THE BASIS OF EMPLOYEE SURVEYS AND IN-PLANT RESEARCH, THE TOTAL COST OF DISCRIMINATION TO AMERICAN BUSINESS AND INDUSTRY IN ACTUAL DOLLARS IS ESTIMATED AT ROUGHLY $30 BILLION ANNUALLY. DISCRIMINATION IN INDUSTRY BEGINS AT THE HIRING GATE WHERE MINORITY GROUPS ARE REFUSED EMPLOYMENT BECAUSE OF RACE, COLOR, RELIGION, NATIONALITY, POLITICAL…

  14. Price Discrimination in Academic Journals.

    Science.gov (United States)

    Joyce, Patrick; Merz, Thomas E.

    1985-01-01

    Analysis of price discrimination (charging different prices to different customers for same product) for 89 academic journals in 6 disciplines reveals: incidence of price discrimination rose between 1974 and 1984, increase in mean institutional (library) subscription price exceeded increase in mean individual subscription price. Journal list…

  15. Children's Perceptions of Gender Discrimination

    Science.gov (United States)

    Brown, Christia Spears; Bigler, Rebecca S.

    2004-01-01

    Children (N = 76; ages 5-10 years) participated in a study designed to examine perceptions of gender discrimination. Children were read scenarios in which a teacher determined outcomes for 2 students (1 boy and 1 girl). Contextual information (i.e., teacher's past behavior), the gender of the target of discrimination (i.e., student), and the…

  16. Endophilia or exophobia: beyond discrimination

    NARCIS (Netherlands)

    Feld, J.F.; Salamanca Acosta, N.; Hamermesh, D.

    2013-01-01

    The immense literature on discrimination treats outcomes as relative: One group suffers compared to another. But does a difference arise because agents discriminate against others—are exophobic—or because they favor their own kind—are endophilic? This difference matters, as the relative importance

  17. Only Some Are Dead Men Walking: Teaching about Race Discrimination and the Death Penalty

    Science.gov (United States)

    Bordt, Rebecca L.

    2004-01-01

    This paper describes an experiential learning exercise I have used to teach race discrimination in my introductory and criminology courses. The exercise is designed to introduce students to the concept of non-conscious forms of racial bias, a form of race discrimination often difficult for students to grasp. Using a hypothetical criminal case,…

  18. Enhancement of ELM by Clustering Discrimination Manifold Regularization and Multiobjective FOA for Semisupervised Classification

    OpenAIRE

    Qing Ye; Hao Pan; Changhua Liu

    2015-01-01

    A novel semisupervised extreme learning machine (ELM) with clustering discrimination manifold regularization (CDMR) framework named CDMR-ELM is proposed for semisupervised classification. By using unsupervised fuzzy clustering method, CDMR framework integrates clustering discrimination of both labeled and unlabeled data with twinning constraints regularization. Aiming at further improving the classification accuracy and efficiency, a new multiobjective fruit fly optimization algorithm (MOFOA)...

  19. Infants Discriminate Voicing and Place of Articulation with Reduced Spectral and Temporal Modulation Cues

    Science.gov (United States)

    Cabrera, Laurianne; Lorenzi, Christian; Bertoncini, Josiane

    2015-01-01

    Purpose: This study assessed the role of spectro-temporal modulation cues in the discrimination of 2 phonetic contrasts (voicing and place) for young infants. Method: A visual-habituation procedure was used to assess the ability of French-learning 6-month-old infants with normal hearing to discriminate voiced versus unvoiced (/aba/-/apa/) and…

  20. Spatial Frequency Discrimination: Effects of Age, Reward, and Practice.

    Directory of Open Access Journals (Sweden)

    Carlijn van den Boomen

    Full Text Available Social interaction starts with perception of the world around you. This study investigated two fundamental issues regarding the development of discrimination of higher spatial frequencies, which are important building blocks of perception. Firstly, it mapped the typical developmental trajectory of higher spatial frequency discrimination. Secondly, it developed and validated a novel design that could be applied to improve atypically developed vision. Specifically, this study examined the effect of age and reward on task performance, practice effects, and motivation (i.e., number of trials completed in a higher spatial frequency (reference frequency: 6 cycles per degree discrimination task. We measured discrimination thresholds in children aged between 7 to 12 years and adults (N = 135. Reward was manipulated by presenting either positive reinforcement or punishment. Results showed a decrease in discrimination thresholds with age, thus revealing that higher spatial frequency discrimination continues to develop after 12 years of age. This development continues longer than previously shown for discrimination of lower spatial frequencies. Moreover, thresholds decreased during the run, indicating that discrimination abilities improved. Reward did not affect performance or improvement. However, in an additional group of 5-6 year-olds (N = 28 punishments resulted in the completion of fewer trials compared to reinforcements. In both reward conditions children aged 5-6 years completed only a fourth or half of the run (64 to 128 out of 254 trials and were not motivated to continue. The design thus needs further adaptation before it can be applied to this age group. Children aged 7-12 years and adults completed the run, suggesting that the design is successful and motivating for children aged 7-12 years. This study thus presents developmental differences in higher spatial frequency discrimination thresholds. Furthermore, it presents a design that can be

  1. Gender-Biased Learning.

    Science.gov (United States)

    Weiss, Ruth Palombo

    2001-01-01

    Looks at how gender shapes the way humans learn from biological and sociological perspectives. Indicates that teachers interact more frequently with males and that trainers should try to overcome gender bias. Suggests that discrimination persists in adult education. (JOW)

  2. Children's perceptions of gender discrimination.

    Science.gov (United States)

    Spears Brown, Christia; Bigler, Rebecca S

    2004-09-01

    Children (N = 76; ages 5-10 years) participated in a study designed to examine perceptions of gender discrimination. Children were read scenarios in which a teacher determined outcomes for 2 students (1 boy and 1 girl). Contextual information (i.e., teacher's past behavior), the gender of the target of discrimination (i.e., student), and the gender of the perpetrator (i.e., teacher) were manipulated. Results indicated that older children were more likely than younger children to make attributions to discrimination when contextual information suggested that it was likely. Girls (but not boys) were more likely to view girls than boys as victims of discrimination, and children with egalitarian gender attitudes were more likely to perceive discrimination than were their peers. Copyright 2004 American Psychological Association

  3. Discriminant projective non-negative matrix factorization.

    Directory of Open Access Journals (Sweden)

    Naiyang Guan

    Full Text Available Projective non-negative matrix factorization (PNMF projects high-dimensional non-negative examples X onto a lower-dimensional subspace spanned by a non-negative basis W and considers W(T X as their coefficients, i.e., X≈WW(T X. Since PNMF learns the natural parts-based representation Wof X, it has been widely used in many fields such as pattern recognition and computer vision. However, PNMF does not perform well in classification tasks because it completely ignores the label information of the dataset. This paper proposes a Discriminant PNMF method (DPNMF to overcome this deficiency. In particular, DPNMF exploits Fisher's criterion to PNMF for utilizing the label information. Similar to PNMF, DPNMF learns a single non-negative basis matrix and needs less computational burden than NMF. In contrast to PNMF, DPNMF maximizes the distance between centers of any two classes of examples meanwhile minimizes the distance between any two examples of the same class in the lower-dimensional subspace and thus has more discriminant power. We develop a multiplicative update rule to solve DPNMF and prove its convergence. Experimental results on four popular face image datasets confirm its effectiveness comparing with the representative NMF and PNMF algorithms.

  4. Racial/Ethnic Workplace Discrimination

    Science.gov (United States)

    Chavez, Laura J.; Ornelas, India J.; Lyles, Courtney R.; Williams, Emily C.

    2014-01-01

    Background Experiences of discrimination are associated with tobacco and alcohol use, and work is a common setting where individuals experience racial/ethnic discrimination. Few studies have evaluated the association between workplace discrimination and these behaviors, and none have described associations across race/ethnicity. Purpose To examine the association between workplace discrimination and tobacco and alcohol use in a large, multistate sample of U.S. adult respondents to the Behavioral Risk Factor Surveillance System survey Reactions to Race Module (2004–2010). Methods Multivariable logistic regression analyses evaluated cross-sectional associations between self-reported workplace discrimination and tobacco (current and daily smoking) and alcohol use (any and heavy use, and binge drinking) among all participants and stratified by race/ethnicity, adjusting for relevant covariates. Data were analyzed in 2013. Results Among respondents, 70,080 completed the workplace discrimination measure. Discrimination was more common among black non-Hispanic (21%), Hispanic (12%), and other race respondents (11%) than white non-Hispanics (4%) (pdiscrimination was associated with current smoking (risk ratio [RR]=1.32, 95% CI=1.19, 1.47), daily smoking (RR=1.41, 95% CI=1.24, 1.61), and heavy drinking (RR=1.11, 95% CI=1.01, 1.22), but not binge or any drinking. Among Hispanics, workplace discrimination was associated with increased heavy and binge drinking, but not any alcohol use or smoking. Workplace discrimination among black non-Hispanics and white Non-Hispanics was associated with increased current and daily smoking, but not alcohol outcomes. Conclusions Workplace discrimination is common, associated with smoking and alcohol use, and merits further policy attention given the impact of these behaviors on morbidity and mortality. PMID:25441232

  5. Timing, Remembering, and Discrimination

    Science.gov (United States)

    Sargisson, Rebecca J; White, K. Geoffrey

    2007-01-01

    Four pigeons were first trained in a timing procedure. In one condition, each trial began with the presentation of an X on the center key, followed by a delay (short or long), after which two side keys were lit. If the delay was short, pecks to the red side key were reinforced. If the delay was long, pecks to the green side key were reinforced. In a second condition, the opposite contingencies applied following presentation of a square on the center key. Choice responses were then tested at 10 time intervals ranging from short to long (1 to 4 s and 4 to 7 s in different conditions). The two timing conditions were combined to create a remembering condition in which correct responding depended upon discrimination of both the sample stimulus (X or square) and the delay interval (short or long). Choices varied systematically across delay in timing conditions, but in remembering conditions, accurate choice at the training delays did not initially generalize to intermediate delays. However, with prolonged training in the remembering task, the response pattern began to resemble that of the timing conditions. Generalization gradients were asymmetrical, in accordance with Weber's Law, in that greater generalization occurred with longer delays than with shorter delays. PMID:17345949

  6. Studies in genetic discrimination. Final progress report

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    We have screened 1006 respondents in a study of genetic discrimination. Analysis of these responses has produced evidence of the range of institutions engaged in genetic discrimination and demonstrates the impact of this discrimination on the respondents to the study. We have found that both ignorance and policy underlie genetic discrimination and that anti-discrimination laws are being violated.

  7. JUSTIFICATION FOR INDIRECT DISCRIMINATION IN EU

    Directory of Open Access Journals (Sweden)

    Cătălina-Adriana Ivănuş

    2014-11-01

    Full Text Available The right to non-discrimination is very important for a civilized society. EU legislation establishes direct and indirect discrimination, harassment, sexual harassment, instruction to discriminate and any less favourable treatment of a woman related to pregnancy or maternity leave as forms of discrimination. The law and the Court of Justice permit the justification of indirect discrimination.

  8. Improving the reading skills of Jordanian students with auditory discrimination problems

    OpenAIRE

    Afaf Abdullah Mukdadi; Abdul-Monim Batiha; Jose Luis Ortega Martin

    2016-01-01

    Background: Some of the developmental problems facing students with difficulties in learning are those related to auditory perception which, in turn, can negatively affect the individual’s learning process. Aim: Evaluating a training program prepared to develop the auditory discrimination skills of students who suffer from auditory discrimination problems. Design: A quasi-experimental research design was used in this study. The study sample was divided into two equal groups: experimen...

  9. Timbre discrimination in musical patterns.

    Science.gov (United States)

    Grey, J M

    1978-08-01

    Most research on timbre perception has studied isolated tones. This study compares timbre discrimination of isolated tones with discrimination in various musical contexts, both single-voiced and multivoiced. Twelve different contexts were used (four isolated tonal comparisons, four single-voice musical patterns, and four multivoice patterns). Listerners judged whether the timbre remained the same or changed during the trial. Two possible versions of any instrumental timbre differed in the physical information used in their synthesis. Three instrumental timbres were tested in all contexts: clarinet, trumpet, and bassoon. The effects of context upon discrimination varied across instruments. The clarinet and trumpet versions were best discriminated in isolated contexts, with discrimination progressively worse in single-voice and multivoice patterns. The bassoon versions were best discriminated in the single-voice patterns, with equal discrimination in the isolated and multivoice cases. It is suggested that these results were due to pronounced physical differences observed between the spectra of the two versions of the bassoon that were not apparent between the versions of the clarinet or trumpet.

  10. Memory-Based Quantity Discrimination in Coyotes (Canis latrans

    Directory of Open Access Journals (Sweden)

    Salif Mahamane

    2014-08-01

    Full Text Available Previous research has shown that the ratio between competing quantities of food significantly mediates coyotes‘ (Canis latrans ability to choose the larger of two food options. These previous findings are consistent with predictions made by Weber‘s Law and indicate that coyotes possess quantity discrimination abilities that are similar to other species. Importantly, coyotes‘ discrimination abilities are similar to domestic dogs (Canis lupus familiaris, indicating that quantitative discrimination may remain stable throughout certain species‘ evolution. However, while previously shown in two domestic dogs, it is unknown whether coyotes possess the ability to discriminate visual quantities from memory. Here, we address this question by displaying different ratios of food quantities to 14 coyotes before placing the choices out of sight. The coyotes were then allowed to select one of either non-visible food quantities. Coyotes‘ discrimination of quantity from memory does not follow Weber‘s Law in this particular task. These results suggest that working memory in coyotes may not be adapted to maintain information regarding quantity as well as in domestic dogs. The likelihood of a coyote‘s choosing the large option increased when it was presented with difficult ratios of food options first, before it was later presented with trials using more easily discriminable ratios, and when the large option was placed on one particular side. This suggests that learning or motivation increased across trials when coyotes experienced difficult ratios first, and that location of food may have been more salient in working memory than quantity of food.

  11. Colour discrimination ellipses in choroideremia.

    Science.gov (United States)

    Seitz, Immanuel P; Jolly, Jasleen K; Dominik Fischer, M; Simunovic, Matthew P

    2018-02-05

    The purpose of this study was to characterise alterations in colour discrimination in a cohort of patients with choroideremia prior to gene therapy, using a test previously validated for use in patients with retinal dystrophies. We tested 20 eyes of 10 patients with a diagnosis of choroideremia and an age-matched cohort of 10 eyes of 10 normal controls using the "Cambridge Colour Test" (CCT), in which subjects are required to distinguish the gap in a C presented in one of 4 orientations in a Stilling-type array. Colour discrimination was probed along eight axes in the CIE L*u*v* colour space, and the resulting data were plotted in the CIE 1976 chromaticity diagram and fitted with least-squares ellipses. Subsequently, we estimated the achromatic area for each subject by calculating the area of the resultant discrimination ellipse and calculated sensitivity thresholds along relevant colour confusion axes. Colour discrimination-as quantified by log 10 of the ellipse area expressed in square 1/1000th 2 units in CIE 1976-was 2.26 (range 1.82 to 2.67) for normal subjects and 3.85 (range 2.35 to 5.41) for choroideremia patients. There was a statistically significant correlation between both achromatic area and red-green colour discrimination at the CCT and BCVA, and to a lesser degree between blue colour discrimination at the CCT and BCVA. The majority of ellipses in choroideremia were aligned close to the tritan axis, and loss of sensitivity was significantly larger in the tritan direction than in the red-green. The majority of our patients demonstrated greater loss in tritan discrimination than in red-green colour discrimination using the CCT. There was a significant correlation between achromatic area and BCVA. In keeping with our current understanding of the machinery of colour vision, there was a significant correlation between BCVA and colour discrimination thresholds, which was stronger for red-green colour discrimination, than for tritan colour discrimination. We

  12. Structural Discrimination and Autonomous Vehicles

    DEFF Research Database (Denmark)

    Liu, Hin-Yan

    2016-01-01

    This paper examines the potential for structural discrimination to be woven into the fabric of autonomous vehicle developments, which remain underexplored and undiscussed. The prospect for structural discrimination arises as a result of the coordinated modes of autonomous vehicle behaviour...... discrimination looms with the possibility of crash optimisation impulses in which a protective shield is cast over those individuals in which society may have a vested interest in prioritising or safeguarding. A stark dystopian scenario is introduced to sketch the contours whereby personal beacons signal...

  13. Sex Discrimination in Education: Theory and Practice.

    Science.gov (United States)

    Shaw, B.

    1979-01-01

    Reviews various perspectives on sex discrimination in schools and colleges, presents case studies of sex discrimination in the English educational system, and distinguishes between sex discrimination and gender forming. Journal availability: see SO 507 421. (DB)

  14. Effect of odor preexposure on acquisition of an odor discrimination in dogs.

    Science.gov (United States)

    Hall, Nathaniel J; Smith, David W; Wynne, Clive D L

    2014-06-01

    In two experiments, we investigated the impact of odor preexposure treatments on the acquisition of an olfactory discrimination in dogs. In the first experiment, four groups of dogs were each given five days' odor-exposure treatment prior to discrimination training. Dogs in the exposure group were exposed to anise extract (S+) for 30 min daily. Dogs in the Pavlovian-relevant pairing group received six daily delayed-conditioning trials to the same S+. The Pavlovian-irrelevant pairing group received conditioning trials to almond extract (S'). Dogs in the control group received no pretreatment. All of the dogs were then trained to detect S+ from a background pine odor (an AX-vs.-X discrimination). The Pavlovian-relevant pairing group acquired the odor discrimination significantly faster than all of the other exposure and control groups, and the remaining groups acquired the discrimination at the same rate as the no-exposure control group. In a second experiment, we extended these results to a within-subjects design using an AX-versus-BX discrimination. Six dogs were simultaneously trained on two different odor discriminations, one discrimination in which the S+ was previously Pavlovian conditioned, and one discrimination in which the S+ was novel. All of the dogs learned the odor discrimination with the previously conditioned S+ faster than they learned the novel odor discrimination, replicating the results of Experiment 1, and demonstrating that familiarity in the form of Pavlovian conditioning enhances odor-discrimination training. The potential mechanisms of the facilitated transfer of a Pavlovian conditioned stimulus to discrimination training are discussed.

  15. Temporal Resolution and Active Auditory Discrimination Skill in Vocal Musicians

    Directory of Open Access Journals (Sweden)

    Kumar, Prawin

    2015-12-01

    Full Text Available Introduction Enhanced auditory perception in musicians is likely to result from auditory perceptual learning during several years of training and practice. Many studies have focused on biological processing of auditory stimuli among musicians. However, there is a lack of literature on temporal resolution and active auditory discrimination skills in vocal musicians. Objective The aim of the present study is to assess temporal resolution and active auditory discrimination skill in vocal musicians. Method The study participants included 15 vocal musicians with a minimum professional experience of 5 years of music exposure, within the age range of 20 to 30 years old, as the experimental group, while 15 age-matched non-musicians served as the control group. We used duration discrimination using pure-tones, pulse-train duration discrimination, and gap detection threshold tasks to assess temporal processing skills in both groups. Similarly, we assessed active auditory discrimination skill in both groups using Differential Limen of Frequency (DLF. All tasks were done using MATLab software installed in a personal computer at 40dBSL with maximum likelihood procedure. The collected data were analyzed using SPSS (version 17.0. Result Descriptive statistics showed better threshold for vocal musicians compared with non-musicians for all tasks. Further, independent t-test showed that vocal musicians performed significantly better compared with non-musicians on duration discrimination using pure tone, pulse train duration discrimination, gap detection threshold, and differential limen of frequency. Conclusion The present study showed enhanced temporal resolution ability and better (lower active discrimination threshold in vocal musicians in comparison to non-musicians.

  16. Temporal Resolution and Active Auditory Discrimination Skill in Vocal Musicians.

    Science.gov (United States)

    Kumar, Prawin; Sanju, Himanshu Kumar; Nikhil, J

    2016-10-01

    Introduction  Enhanced auditory perception in musicians is likely to result from auditory perceptual learning during several years of training and practice. Many studies have focused on biological processing of auditory stimuli among musicians. However, there is a lack of literature on temporal resolution and active auditory discrimination skills in vocal musicians. Objective  The aim of the present study is to assess temporal resolution and active auditory discrimination skill in vocal musicians. Method  The study participants included 15 vocal musicians with a minimum professional experience of 5 years of music exposure, within the age range of 20 to 30 years old, as the experimental group, while 15 age-matched non-musicians served as the control group. We used duration discrimination using pure-tones, pulse-train duration discrimination, and gap detection threshold tasks to assess temporal processing skills in both groups. Similarly, we assessed active auditory discrimination skill in both groups using Differential Limen of Frequency (DLF). All tasks were done using MATLab software installed in a personal computer at 40dBSL with maximum likelihood procedure. The collected data were analyzed using SPSS (version 17.0). Result  Descriptive statistics showed better threshold for vocal musicians compared with non-musicians for all tasks. Further, independent t -test showed that vocal musicians performed significantly better compared with non-musicians on duration discrimination using pure tone, pulse train duration discrimination, gap detection threshold, and differential limen of frequency. Conclusion  The present study showed enhanced temporal resolution ability and better (lower) active discrimination threshold in vocal musicians in comparison to non-musicians.

  17. Classification of astrocyto-mas and meningiomas using statistical discriminant analysis on MRI data

    International Nuclear Information System (INIS)

    Siromoney, Anna; Prasad, G.N.S.; Raghuram, Lakshminarayan; Korah, Ipeson; Siromoney, Arul; Chandrasekaran, R.

    2001-01-01

    The objective of this study was to investigate the usefulness of Multivariate Discriminant Analysis for classifying two groups of primary brain tumours, astrocytomas and meningiomas, from Magnetic Resonance Images. Discriminant analysis is a multivariate technique concerned with separating distinct sets of objects and with allocating new objects to previously defined groups. Allocation or classification rules are usually developed from learning examples in a supervised learning environment. Data from signal intensity measurements in the multiple scan performed on each patient in routine clinical scanning was analysed using Fisher's Classification, which is one method of discriminant analysis

  18. Discrimination of chromosome by autoradiography

    International Nuclear Information System (INIS)

    Masubuchi, Masanori

    1975-01-01

    This paper describes discrimination of chromosome by autoradiography. In this method, the difference in DNA synthetic phase between each chromosome was used as a standard, and the used chromosome was in metaphase, as morphological characteristics were markedly in this phase. Cell cycle and autoradiography with 3 H-thymidine were also examined. In order to discriminate chromosome by autoradiography, it was effective to utilize the labelled pattern in late DNA synthetic phase, where asynchronous replication of chromosome appeared most obviously. DNA synthesis in chromosome was examined in each DNA synthetic phase by culturing the chromosome after the treatment with 3 H-thymidine and altering the time to prepare chromosome specimen. Discrimination of chromosome in plants and animals by autoradiography was also mentioned. It was noticed as a structural and functional discrimination of chromosome to observe amino acid uptake into chromosome protein and to utilize the difference in labelled pattern between the sites of chromosome. (K. Serizawa)

  19. Fast discriminative latent Dirichlet allocation

    Data.gov (United States)

    National Aeronautics and Space Administration — This is the code for fast discriminative latent Dirichlet allocation, which is an algorithm for topic modeling and text classification. The related paper is at...

  20. Face adaptation improves gender discrimination.

    Science.gov (United States)

    Yang, Hua; Shen, Jianhong; Chen, Juan; Fang, Fang

    2011-01-01

    Adaptation to a visual pattern can alter the sensitivities of neuronal populations encoding the pattern. However, the functional roles of adaptation, especially in high-level vision, are still equivocal. In the present study, we performed three experiments to investigate if face gender adaptation could affect gender discrimination. Experiments 1 and 2 revealed that adapting to a male/female face could selectively enhance discrimination for male/female faces. Experiment 3 showed that the discrimination enhancement induced by face adaptation could transfer across a substantial change in three-dimensional face viewpoint. These results provide further evidence suggesting that, similar to low-level vision, adaptation in high-level vision could calibrate the visual system to current inputs of complex shapes (i.e. face) and improve discrimination at the adapted characteristic. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Ending Sex Discrimination in Academia.

    Science.gov (United States)

    Broad, William J.

    1980-01-01

    The controversy surrounding the sex discrimination suit, brought seven years ago by a University of Minnesota chemist, is discussed as it relates to the current court decision in which the plaintiff was awarded $100,000.00. (Author/SA)

  2. EU Law and Multiple Discrimination

    DEFF Research Database (Denmark)

    Nielsen, Ruth

    2006-01-01

    In EU law, nationality and gender were the only equality issues on the legal agenda from the outset in 1958 and for about 40 years. Multiple discrimination was not addressed until the 1990's. The intersectionality approach which has been widely discussed outside Europe has mainly been used...... with a view to gendermainstreaming the fight against other kinds of discrimination (on grounds of ethnic origin, age, etc)....

  3. Sexual orientation discrimination in hiring

    OpenAIRE

    Doris Weichselbaumer

    2000-01-01

    Little research has been done to examine discrimination against gays and lesbians in the labor market. Badgett (1995) conducted the only previous study investigating labor market outcomes of gays and lesbians using a random data set. However, due to the structure of the data, the wage differential between heterosexuals and gays and lesbians that is found can not be directly assigned to employer discrimination. Some gays and lesbians might deploy passing strategies to hide their sexual orienta...

  4. Discrimination and Equality of Opportunity

    OpenAIRE

    J. Ignacio García-Pérez; Antonio Villar

    2009-01-01

    This paper presents a measure of social discrimination based on the principle of equality of opportunity. According to this principle we only have to care about the inequality derived from people’s differential circumstances (and not about outcome differences due to people’s diverse degree of effort). We propose approaching the measurement of group discrimination as the “welfare loss” attributed to the inequality between social groups of similar characteristics. We also provide an empirical a...

  5. Unambiguous discrimination among oracle operators

    International Nuclear Information System (INIS)

    Chefles, Anthony; Kitagawa, Akira; Takeoka, Masahiro; Sasaki, Masahide; Twamley, Jason

    2007-01-01

    We address the problem of unambiguous discrimination among oracle operators. The general theory of unambiguous discrimination among unitary operators is extended with this application in mind. We prove that entanglement with an ancilla cannot assist any discrimination strategy for commuting unitary operators. We also obtain a simple, practical test for the unambiguous distinguishability of an arbitrary set of unitary operators on a given system. Using this result, we prove that the unambiguous distinguishability criterion is the same for both standard and minimal oracle operators. We then show that, except in certain trivial cases, unambiguous discrimination among all standard oracle operators corresponding to integer functions with fixed domain and range is impossible. However, we find that it is possible to unambiguously discriminate among the Grover oracle operators corresponding to an arbitrarily large unsorted database. The unambiguous distinguishability of standard oracle operators corresponding to totally indistinguishable functions, which possess a strong form of classical indistinguishability, is analysed. We prove that these operators are not unambiguously distinguishable for any finite set of totally indistinguishable functions on a Boolean domain and with arbitrary fixed range. Sets of such functions on a larger domain can have unambiguously distinguishable standard oracle operators, and we provide a complete analysis of the simplest case, that of four functions. We also examine the possibility of unambiguous oracle operator discrimination with multiple parallel calls and investigate an intriguing unitary superoperator transformation between standard and entanglement-assisted minimal oracle operators

  6. LLNL's Regional Seismic Discrimination Research

    International Nuclear Information System (INIS)

    Hanley, W; Mayeda, K; Myers, S; Pasyanos, M; Rodgers, A; Sicherman, A; Walter, W

    1999-01-01

    As part of the Department of Energy's research and development effort to improve the monitoring capability of the planned Comprehensive Nuclear-Test-Ban Treaty international monitoring system, Lawrence Livermore Laboratory (LLNL) is testing and calibrating regional seismic discrimination algorithms in the Middle East, North Africa and Western Former Soviet Union. The calibration process consists of a number of steps: (1) populating the database with independently identified regional events; (2) developing regional boundaries and pre-identifying severe regional phase blockage zones; (3) measuring and calibrating coda based magnitude scales; (4a) measuring regional amplitudes and making magnitude and distance amplitude corrections (MDAC); (4b) applying the DOE modified kriging methodology to MDAC results using the regionalized background model; (5) determining the thresholds of detectability of regional phases as a function of phase type and frequency; (6) evaluating regional phase discriminant performance both singly and in combination; (7) combining steps 1-6 to create a calibrated discrimination surface for each stations; (8) assessing progress and iterating. We have now developed this calibration procedure to the point where it is fairly straightforward to apply earthquake-explosion discrimination in regions with ample empirical data. Several of the steps outlined above are discussed in greater detail in other DOE papers in this volume or in recent publications. Here we emphasize the results of the above process: station correction surfaces and their improvement to discrimination results compared with simpler calibration methods. Some of the outstanding discrimination research issues involve cases in which there is little or no empirical data. For example in many cases there is no regional nuclear explosion data at IMS stations or nearby surrogates. We have taken two approaches to this problem, first finding and using mining explosion data when available, and

  7. Discriminative predation: Simultaneous and sequential encounter experiments

    Directory of Open Access Journals (Sweden)

    C. D. BEATTY, D.W.FRANKS

    2012-08-01

    Full Text Available There are many situations in which the ability of animals to distinguish between two similar looking objects can have significant selective consequences. For example, the objects that require discrimination may be edible versus defended prey, predators versus non-predators, or mates of varying quality. Working from the premise that there are situations in which discrimination may be more or less successful, we hypothesized that individuals find it more difficult to distinguish between stimuli when they encounter them sequentially rather than simultaneously. Our study has wide biological and psychological implications from the perspective of signal perception, signal evolution, and discrimination, and could apply to any system where individuals are making relative judgments or choices between two or more stimuli or signals. While this is a general principle that might seem intuitive, it has not been experimentally tested in this context, and is often not considered in the design of models or experiments, or in the interpretation of a wide range of studies. Our study is different from previous studies in psychology in that a the level of similarity of stimuli are gradually varied to obtain selection gradients, and b we discuss the implications of our study for specific areas in ecology, such as the level of perfection of mimicry in predator-prey systems. Our experiments provide evidence that it is indeed more difficult to distinguish between stimuli – and to learn to distinguish between stimuli – when they are encountered sequentially rather than simultaneously, even if the intervening time interval is short [Current Zoology 58 (4: 649–657, 2012].

  8. 45 CFR 1624.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Discrimination prohibited. 1624.4 Section 1624.4... AGAINST DISCRIMINATION ON THE BASIS OF DISABILITY § 1624.4 Discrimination prohibited. (a) No qualified... the benefits of, or otherwise be subjected to discrimination by any legal services program, directly...

  9. 14 CFR 399.36 - Unreasonable discrimination.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Unreasonable discrimination. 399.36 Section... Unreasonable discrimination. (a) As used in this section: (1) Unreasonable discrimination means unjust discrimination or unreasonable preference or prejudice; and (2) Rate means rate, fare, or charge. (b) Except in...

  10. 20 CFR 405.30 - Discrimination complaints.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Discrimination complaints. 405.30 Section 405... INITIAL DISABILITY CLAIMS Introduction, General Description, and Definitions § 405.30 Discrimination... that an adjudicator has improperly discriminated against you, you may file a discrimination complaint...

  11. Unambiguous discrimination of mixed quantum states

    International Nuclear Information System (INIS)

    Zhang Chi; Feng Yuan; Ying Mingsheng

    2006-01-01

    The problem of unambiguous discrimination between mixed quantum states is addressed by isolating the part of each mixed state which has no contribution to discrimination and by employing the strategy of set discrimination of pure states. A necessary and sufficient condition of unambiguous mixed state discrimination is presented. An upper bound of the efficiency is also derived

  12. Deep Meta-Learning: Learning to Learn in the Concept Space

    OpenAIRE

    Zhou, Fengwei; Wu, Bin; Li, Zhenguo

    2018-01-01

    Few-shot learning remains challenging for meta-learning that learns a learning algorithm (meta-learner) from many related tasks. In this work, we argue that this is due to the lack of a good representation for meta-learning, and propose deep meta-learning to integrate the representation power of deep learning into meta-learning. The framework is composed of three modules, a concept generator, a meta-learner, and a concept discriminator, which are learned jointly. The concept generator, e.g. a...

  13. Discrimination of familiar human faces in dogs (Canis familiaris)

    Science.gov (United States)

    Huber, Ludwig; Racca, Anaïs; Scaf, Billy; Virányi, Zsófia; Range, Friederike

    2013-01-01

    Faces are an important visual category for many taxa, and the human face is no exception to this. Because faces differ in subtle ways and possess many idiosyncratic features, they provide a rich source of perceptual cues. A fair amount of those cues are learned through social interactions and are used for future identification of individual humans. These effects of individual experience can be studied particularly well in hetero-specific face perception. Domestic dogs represent a perfect model in this respect, due to their proved ability to extract important information from the human face in socio-communicative interactions. There is also suggestive evidence that dogs can identify their owner or other familiar human individuals by using visual information from the face. However, most studies have used only dogs’ looking behavior to examine their visual processing of human faces and it has been demonstrated only that dogs can differentiate between familiar and unknown human faces. Here, we examined the dog's ability to discriminate the faces of two familiar persons by active choice (approach and touch). Furthermore, in successive stages of the experiment we investigated how well dogs discriminate humans in different representations by systematically reducing the informational richness and the quality of the stimuli. We found a huge inter-individual and inter-stage variance in performance, indicating differences across dogs in their learning ability as well as their selection of discriminative cues. On a group level, the performance of dogs significantly decreased when they were presented with pictures of human heads after having learned to discriminate the real heads, and when – after relearning – confronted with the same pictures showing only the inner parts of the heads. However, as two dogs quickly mastered all stages, we conclude that dogs are in principle able to discriminate people on the basis of visual information from their faces and by making active

  14. THE JURIDICAL PROTECTION ON GLOBAL DISCRIMINATION

    OpenAIRE

    CRISTINA OTOVESCU FRĂSIE

    2012-01-01

    In this study I wished to evidence the main juridical documents referring to discrimination, adopted world wide by the United Nations Organization. Thus, can be identified several types of definitions concerning the discrimination against women, the race discrimination, the torture etc. within the analyzed documents. The democratic countries have laws that punish the discrimination, but, unfortunately, there are discrimination phenomena for example regarding the ethnicity, the gender, the lan...

  15. Achieving non-discrimination in data release

    OpenAIRE

    Zhang, Lu; Wu, Yongkai; Wu, Xintao

    2016-01-01

    Discrimination discovery and prevention/removal are increasingly important tasks in data mining. Discrimination discovery aims to unveil discriminatory practices on the protected attribute (e.g., gender) by analyzing the dataset of historical decision records, and discrimination prevention aims to remove discrimination by modifying the biased data before conducting predictive analysis. In this paper, we show that the key to discrimination discovery and prevention is to find the meaningful par...

  16. Ethnic Discrimination in Education: The Swiss Case

    OpenAIRE

    Philipp Bauer; George Sheldon

    2008-01-01

    This paper investigates the role that discrimination plays in the educational marginalization of foreign youth commonly observed in European countries with a long guestworker tradition. Economic theory offers two basic explanations for discrimination of this form: taste-based discrimination arising from personal prejudices and statistical discrimination stemming from ability uncertainty. Which theory applies in reality has important policy implications. If taste-based discrimination is the so...

  17. Discriminator with a small hysteresis

    International Nuclear Information System (INIS)

    Korol'ko, E.V.; Suvorov, V.V.

    1977-01-01

    The electric circuitry of a discriminator is described which comprises a current shaping circuit, a tunnel diode and a shunting circuit. The novel shunting circuit design ensures a small hysteresis and quick response of the system as a whole. The shunting circuit employs two n-p-n and p-n-p type transistors, their emitters being interconnected and the bases being coupled to voltage dividers. A diagram is presented to illustrate the function of the tunnel diode - shunting circuit combination. The discriminator has the following characteristics: hysteresis about 5%, response time about 15 nsec., attenuation factor about 3. The discriminator is useful for forming pulses having a duration equal to the threshold exceeding time

  18. EU Law and Multiple Discrimination

    DEFF Research Database (Denmark)

    Nielsen, Ruth

    2006-01-01

    In EU law, nationality and gender were the only equality issues on the legal agenda from the outset in 1958 and for about 40 years. Multiple discrimination was not addressed until the 1990's. The intersectionality approach which has been widely discussed outside Europe has mainly been used with a...... with a view to gendermainstreaming the fight against other kinds of discrimination (on grounds of ethnic origin, age, etc).......In EU law, nationality and gender were the only equality issues on the legal agenda from the outset in 1958 and for about 40 years. Multiple discrimination was not addressed until the 1990's. The intersectionality approach which has been widely discussed outside Europe has mainly been used...

  19. Tumor classification based on orthogonal linear discriminant analysis.

    Science.gov (United States)

    Wang, Huiya; Zhang, Shanwen

    2014-01-01

    Gene expression profiles have great potential for accurate tumor diagnosis. It is expected to enable us to diagnose tumors precisely and systematically, and also bring the researchers of machine learning two challenges, the curse of dimensionality and the small sample size problems. We propose a manifold learning based dimensional reduction algorithm named orthogonal local discriminant embedding (O-LDE) and apply it to tumor classification. Comparing with the classical local discriminant embedding (LDE), O-LDE aims to obtain an orthogonal linear projection matrix by solving an optimization problem. After being projected into a low-dimensional subspace by O-LDE, the data points of the same class maintain their intrinsic neighbor relations, whereas the neighboring points of the different classes are far from each other. Experimental results on a public tumor dataset validate the effectiveness and feasibility of the proposed algorithm.

  20. Supervised non-negative tensor factorization for automatic hyperspectral feature extraction and target discrimination

    Science.gov (United States)

    Anderson, Dylan; Bapst, Aleksander; Coon, Joshua; Pung, Aaron; Kudenov, Michael

    2017-05-01

    Hyperspectral imaging provides a highly discriminative and powerful signature for target detection and discrimination. Recent literature has shown that considering additional target characteristics, such as spatial or temporal profiles, simultaneously with spectral content can greatly increase classifier performance. Considering these additional characteristics in a traditional discriminative algorithm requires a feature extraction step be performed first. An example of such a pipeline is computing a filter bank response to extract spatial features followed by a support vector machine (SVM) to discriminate between targets. This decoupling between feature extraction and target discrimination yields features that are suboptimal for discrimination, reducing performance. This performance reduction is especially pronounced when the number of features or available data is limited. In this paper, we propose the use of Supervised Nonnegative Tensor Factorization (SNTF) to jointly perform feature extraction and target discrimination over hyperspectral data products. SNTF learns a tensor factorization and a classification boundary from labeled training data simultaneously. This ensures that the features learned via tensor factorization are optimal for both summarizing the input data and separating the targets of interest. Practical considerations for applying SNTF to hyperspectral data are presented, and results from this framework are compared to decoupled feature extraction/target discrimination pipelines.

  1. two-group discriminant problem

    Directory of Open Access Journals (Sweden)

    Constantine Loucopoulos

    1997-01-01

    Full Text Available A mixed-integer programming model (MIP incorporating prior probabilities for the two-group discriminant problem is presented. Its classificatory performance is compared against that of Fisher's linear discrimininant function (LDF and Smith's quadradic discriminant function (QDF for simulated data from normal and nonnormal populations for different settings of the prior probabilities of group membership. The proposed model is shown to outperform both LDF and QDF for most settings of the prior probabilities when the data are generated from nonnormal populations but underperforms the parametric models for data generated from normal populations.

  2. Employment Discrimination against LGBT Utahns

    OpenAIRE

    Rosky, Clifford; Mallory, Christy; Smith, Jenni; Badgett, M.V. Lee

    2011-01-01

    This study analyzes data from a 2010 survey on the employment experiences of 939 LGBT people living in Utah.  The study found that 44% of LGB people and 66% of transgender people in Utah have experienced employment discrimination.  The data showed that employment discrimination based on sexual orientation and gender identity currently occurs in Utah, with close to 30% of LGB respondents and 45% of transgender respondents reporting that they experienced some form of workplace harassment on a w...

  3. Discrimination Discovery and Prevention in Data Mining: A Survey

    OpenAIRE

    Jagriti Singh; Prof. Dr. S. S. Sane

    2014-01-01

    Data Mining is the computation process of discovering knowledge or patterns in large data sets. But extract knowledge without violation such as privacy and non-discrimination is most difficult and challenging. This is mainly because of data mining techniques such as classification rules are actually learned by the system from the training data and training data sets itself are biased in what regards discriminatory (sensitive) attributes like gender, race, religion, etc. As a r...

  4. DISCRIMINATION BY ASSOCIATION IN EUROPEAN LAW

    Directory of Open Access Journals (Sweden)

    Cătălina-Adriana Ivănuș

    2013-11-01

    Full Text Available The european law prohibit direct and indirect discrimination and harrasment on grounds of sex, racial or ethnic, religion or belief, disability, age or sexual orientation. The question is what is the situation when someone is discriminated on can claim to be the victim of unlawful discrimination because he or she is associated with another person who has the protected characteristic. The the Court of Justice of the European Union’s judgment in Coleman v Attridge Law and Steve Law confirms, for the first time in European law, the existence of the concept of discrimination by association. In this article I examine the implications of this case on all conceps of discrimination concepts of discrimination in European law (direct discrimination, indirect discrimination and harassment. I also examine the application of discrimination by association to grounds other than disability.

  5. Trade Openness and Gender Discrimination

    OpenAIRE

    Arbache, Jorge Saba; Helena Santos, Marina

    2005-01-01

    This paper investigates the impact of trade liberalization on gender wage discrimination. The authors employ a simple method that is able to capture the direct impacts of openness at the industry level on the gender wages. The authors find evidence that increasing openness is associated with narrowing wage gap, which results mainly from men’s wages declining. This is consistent with the Be...

  6. Spatial layout affects speed discrimination

    Science.gov (United States)

    Verghese, P.; Stone, L. S.

    1997-01-01

    We address a surprising result in a previous study of speed discrimination with multiple moving gratings: discrimination thresholds decreased when the number of stimuli was increased, but remained unchanged when the area of a single stimulus was increased [Verghese & Stone (1995). Vision Research, 35, 2811-2823]. In this study, we manipulated the spatial- and phase relationship between multiple grating patches to determine their effect on speed discrimination thresholds. In a fusion experiment, we merged multiple stimulus patches, in stages, into a single patch. Thresholds increased as the patches were brought closer and their phase relationship was adjusted to be consistent with a single patch. Thresholds increased further still as these patches were fused into a single patch. In a fission experiment, we divided a single large patch into multiple patches by superimposing a cross with luminance equal to that of the background. Thresholds decreased as the large patch was divided into quadrants and decreased further as the quadrants were maximally separated. However, when the cross luminance was darker than the background, it was perceived as an occluder and thresholds, on average, were unchanged from that for the single large patch. A control experiment shows that the observed trend in discrimination thresholds is not due to the differences in perceived speed of the stimuli. These results suggest that the parsing of the visual image into entities affects the combination of speed information across space, and that each discrete entity effectively provides a single independent estimate of speed.

  7. Don't demotivate, discriminate

    NARCIS (Netherlands)

    J.J.A. Kamphorst (Jurjen); O.H. Swank (Otto)

    2013-01-01

    markdownabstract__Abstract__ This paper offers a new theory of discrimination in the workplace. We consider a manager who has to assign two tasks to two employees. The manager has superior information about the employees' abilities. We show that besides an equilibrium where the manager does not

  8. Sex Stereotyping and Sex Discrimination

    Science.gov (United States)

    Hegarty, Moira

    1977-01-01

    Although unable to find any evidence to indicate that secondary schools in Canada have or have not made any progress in reducing sex stereotyping or sex discrimination, the author states that the Canadian educational system is aware of its responsibility to uphold non-sexist standards for its young students. Discusses some research done on undoing…

  9. Contextual Advantage for State Discrimination

    Science.gov (United States)

    Schmid, David; Spekkens, Robert W.

    2018-02-01

    Finding quantitative aspects of quantum phenomena which cannot be explained by any classical model has foundational importance for understanding the boundary between classical and quantum theory. It also has practical significance for identifying information processing tasks for which those phenomena provide a quantum advantage. Using the framework of generalized noncontextuality as our notion of classicality, we find one such nonclassical feature within the phenomenology of quantum minimum-error state discrimination. Namely, we identify quantitative limits on the success probability for minimum-error state discrimination in any experiment described by a noncontextual ontological model. These constraints constitute noncontextuality inequalities that are violated by quantum theory, and this violation implies a quantum advantage for state discrimination relative to noncontextual models. Furthermore, our noncontextuality inequalities are robust to noise and are operationally formulated, so that any experimental violation of the inequalities is a witness of contextuality, independently of the validity of quantum theory. Along the way, we introduce new methods for analyzing noncontextuality scenarios and demonstrate a tight connection between our minimum-error state discrimination scenario and a Bell scenario.

  10. Sex Discrimination in Employment Practices.

    Science.gov (United States)

    California Univ., Los Angeles. Univ. Extension.

    The conference on sex discrimination in employment practices was held at the University of California at Los Angeles in cooperation with the Women's Bureau of the Department of Labor. Speeches included: (1) "New Legislation--New Action" by Rosalind K. Loring and William Foster, (2) "Compliance Policies and Procedures for Business and Industry" by…

  11. Social Status Correlates of Reporting Racial Discrimination and Gender Discrimination among Racially Diverse Women

    OpenAIRE

    Ro, Annie E.; Choi, Kyung-Hee

    2009-01-01

    The growing body of research on discrimination and health indicates a deleterious effect of discrimination on various health outcomes. However, less is known about the sociodemographic correlates of reporting racial discrimination and gender discrimination among racially diverse women. We examined the associations of social status characteristics with lifetime experiences of racial discrimination and gender discrimination using a racially-diverse sample of 754 women attending family planning ...

  12. The effects of acute nicotine on contextual safety discrimination.

    Science.gov (United States)

    Kutlu, Munir G; Oliver, Chicora; Gould, Thomas J

    2014-11-01

    Anxiety disorders, such as post-traumatic stress disorder (PTSD), may be related to an inability to distinguish safe versus threatening environments and to extinguish fear memories. Given the high rate of cigarette smoking in patients with PTSD, as well as the recent finding that an acute dose of nicotine impairs extinction of contextual fear memory, we conducted a series of experiments to investigate the effect of acute nicotine in an animal model of contextual safety discrimination. Following saline or nicotine (at 0.0275, 0.045, 0.09 and 0.18 mg/kg) administration, C57BL/6J mice were trained in a contextual discrimination paradigm, in which the subjects received presentations of conditioned stimuli (CS) that co-terminated with a foot-shock in one context (context A (CXA)) and only CS presentations without foot-shock in a different context (context B (CXB)). Therefore, CXA was designated as the 'dangerous context', whereas CXB was designated as the 'safe context'. Our results suggested that saline-treated animals showed a strong discrimination between dangerous and safe contexts, while acute nicotine dose-dependently impaired contextual safety discrimination (Experiment 1). Furthermore, our results demonstrate that nicotine-induced impairment of contextual safety discrimination learning was not a result of increased generalized freezing (Experiment 2) or contingent on the common CS presentations in both contexts (Experiment 3). Finally, our results show that increasing the temporal gap between CXA and CXB during training abolished the impairing effects of nicotine (Experiment 4). The findings of this study may help link nicotine exposure to the safety learning deficits seen in anxiety disorder and PTSD patients. © The Author(s) 2014.

  13. Dogs can discriminate emotional expressions of human faces.

    Science.gov (United States)

    Müller, Corsin A; Schmitt, Kira; Barber, Anjuli L A; Huber, Ludwig

    2015-03-02

    The question of whether animals have emotions and respond to the emotional expressions of others has become a focus of research in the last decade [1-9]. However, to date, no study has convincingly shown that animals discriminate between emotional expressions of heterospecifics, excluding the possibility that they respond to simple cues. Here, we show that dogs use the emotion of a heterospecific as a discriminative cue. After learning to discriminate between happy and angry human faces in 15 picture pairs, whereby for one group only the upper halves of the faces were shown and for the other group only the lower halves of the faces were shown, dogs were tested with four types of probe trials: (1) the same half of the faces as in the training but of novel faces, (2) the other half of the faces used in training, (3) the other half of novel faces, and (4) the left half of the faces used in training. We found that dogs for which the happy faces were rewarded learned the discrimination more quickly than dogs for which the angry faces were rewarded. This would be predicted if the dogs recognized an angry face as an aversive stimulus. Furthermore, the dogs performed significantly above chance level in all four probe conditions and thus transferred the training contingency to novel stimuli that shared with the training set only the emotional expression as a distinguishing feature. We conclude that the dogs used their memories of real emotional human faces to accomplish the discrimination task. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Hippocampal-cortical contributions to strategic exploration during perceptual discrimination.

    Science.gov (United States)

    Voss, Joel L; Cohen, Neal J

    2017-06-01

    The hippocampus is crucial for long-term memory; its involvement in short-term or immediate expressions of memory is more controversial. Rodent hippocampus has been implicated in an expression of memory that occurs on-line during exploration termed "vicarious trial-and-error" (VTE) behavior. VTE occurs when rodents iteratively explore options during perceptual discrimination or at choice points. It is strategic in that it accelerates learning and improves later memory. VTE has been associated with activity of rodent hippocampal neurons, and lesions of hippocampus disrupt VTE and associated learning and memory advantages. Analogous findings of VTE in humans would support the role of hippocampus in active use of short-term memory to guide strategic behavior. We therefore measured VTE using eye-movement tracking during perceptual discrimination and identified relevant neural correlates with functional magnetic resonance imaging. A difficult perceptual-discrimination task was used that required visual information to be maintained during a several second trial, but with no long-term memory component. VTE accelerated discrimination. Neural correlates of VTE included robust activity of hippocampus and activity of a network of medial prefrontal and lateral parietal regions involved in memory-guided behavior. This VTE-related activity was distinct from activity associated with simply viewing visual stimuli and making eye movements during the discrimination task, which occurred in regions frequently associated with visual processing and eye-movement control. Subjects were mostly unaware of performing VTE, thus further distancing VTE from explicit long-term memory processing. These findings bridge the rodent and human literatures on neural substrates of memory-guided behavior, and provide further support for the role of hippocampus and a hippocampal-centered network of cortical regions in the immediate use of memory in on-line processing and the guidance of behavior. © 2017

  15. Within centre evaluation of hypercalcaemia discriminant

    DEFF Research Database (Denmark)

    Nielsen, Bo Friis; Conradsen, Knut

    1996-01-01

    Diagnostic hypercalcaemia discriminant functions, discriminating between clinically significant and non-significant hypercalcaemia, were tested 5 years after their development in order to evaluate the impact of time on their diagnostic capacity. Two populations, consisting of 257 and 129 patients...

  16. 14 CFR 1250.103 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Discrimination prohibited. 1250.103 Section 1250.103 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION NONDISCRIMINATION IN... Discrimination prohibited. ...

  17. Discrimination performance in aging is vulnerable to interference and dissociable from spatial memory

    Science.gov (United States)

    Johnson, Sarah A.; Sacks, Patricia K.; Turner, Sean M.; Gaynor, Leslie S.; Ormerod, Brandi K.; Maurer, Andrew P.; Bizon, Jennifer L.

    2016-01-01

    Hippocampal-dependent episodic memory and stimulus discrimination abilities are both compromised in the elderly. The reduced capacity to discriminate between similar stimuli likely contributes to multiple aspects of age-related cognitive impairment; however, the association of these behaviors within individuals has never been examined in an animal model. In the present study, young and aged F344×BN F1 hybrid rats were cross-characterized on the Morris water maze test of spatial memory and a dentate gyrus-dependent match-to-position test of spatial discrimination ability. Aged rats showed overall impairments relative to young in spatial learning and memory on the water maze task. Although young and aged learned to apply a match-to-position response strategy in performing easy spatial discriminations within a similar number of trials, a majority of aged rats were impaired relative to young in performing difficult spatial discriminations on subsequent tests. Moreover, all aged rats were susceptible to cumulative interference during spatial discrimination tests, such that error rate increased on later trials of test sessions. These data suggest that when faced with difficult discriminations, the aged rats were less able to distinguish current goal locations from those of previous trials. Increasing acetylcholine levels with donepezil did not improve aged rats’ abilities to accurately perform difficult spatial discriminations or reduce their susceptibility to interference. Interestingly, better spatial memory abilities were not significantly associated with higher performance on difficult spatial discriminations. This observation, along with the finding that aged rats made more errors under conditions in which interference was high, suggests that match-to-position spatial discrimination performance may rely on extra-hippocampal structures such as the prefrontal cortex, in addition to the dentate gyrus. PMID:27317194

  18. Fairness Testing: Testing Software for Discrimination

    OpenAIRE

    Galhotra, Sainyam; Brun, Yuriy; Meliou, Alexandra

    2017-01-01

    This paper defines software fairness and discrimination and develops a testing-based method for measuring if and how much software discriminates, focusing on causality in discriminatory behavior. Evidence of software discrimination has been found in modern software systems that recommend criminal sentences, grant access to financial products, and determine who is allowed to participate in promotions. Our approach, Themis, generates efficient test suites to measure discrimination. Given a sche...

  19. A simple neutron-gamma discriminating system

    International Nuclear Information System (INIS)

    Liu Zhongming; Xing Shilin; Wang Zhongmin

    1986-01-01

    A simple neutron-gamma discriminating system is described. A detector and a pulse shape discriminator are suitable for the neutron-gamma discriminating system. The influence of the constant fraction discriminator threshold energy on the neutron-gamma resolution properties is shown. The neutron-gamma timing distributions from an 241 Am-Be source, 2.5 MeV neutron beam and 14 MeV neutron beam are presented

  20. Discrimination and Exiting Homelessness among Homeless Adolescents

    OpenAIRE

    Milburn, Norweeta G.; Ayala, George; Rice, Eric; Batterham, Philip; Rotheram-Borus, Mary Jane

    2006-01-01

    This paper examines how newly homeless adolescents’ discrimination experiences were associated with exiting homelessness after six months. A sample of 262 homeless adolescents, aged 12 to 20 years, were recruited and followed longitudinally (six-month retention rate = 88%). Discrimination was related to being gay, lesbian, or bisexual (LGB). Discrimination from family was related to exiting homelessness. Other than those who were LGB, adolescents who reported discrimination from their familie...

  1. Illustrations of Price Discrimination in Baseball

    OpenAIRE

    Daniel, Rascher; Andrew, Schwarz

    2010-01-01

    Price discrimination of this nature, focused on differing degrees of quality, bundled goods, volume discounts, and other forms of second-degree price discrimination, is commonplace in MLB. Indeed, it is safe to say that every single MLB ticket is sold under some form of price discrimination. As teams grow increasingly sophisticated in their pricing strategies, price discrimination is becoming more precise, more wide-spread, and more profitable, while at the same time providing for more oppo...

  2. An easy-to-hard effect after nonreinforced preexposure in a sweetness discrimination.

    Science.gov (United States)

    Sanjuán, María Del Carmen; Nelson, James Byron; Alonso, Gumersinda

    2014-09-01

    Experiments 1A and 1B used a taste-aversion procedure with rats to demonstrate that exposure to easily discriminated flavors along a dimension (1 % and 10 % sucrose) can facilitate learning a subsequent hard discrimination (4 % and 7 % sucrose) when one of those flavors is paired with illness. Experiment 1A compared the effects of preexposure to the easily discriminated flavors against exposure to the same stimuli used in the discrimination training or no exposure at all. Experiment 1B replicated the conditions in Experiment 1A, with 2 additional days of training and unrestricted access to the flavors on CS+/CS- trials in discrimination training. Contrary to findings with multidimensional stimuli (Scahill & Mackintosh, Journal of Experimental Psychology: Animal Behavior Processes, 30, 96-103, 2004; Suret & McLaren, The Quarterly Journal of Experimental Psychology, 56B, 30-42, 2003), we found that preexposure to the easily discriminable stimuli varying along a single dimension of sweetness facilitated subsequent discrimination training over the other conditions in each experiment. We discuss the results in terms of the ideas presented by Gibson (1969) and Mackintosh (Psychological Review, 82, 276-298, 1975) and in terms of hedonic variables not considered by theories of perceptual learning.

  3. Distribution-free discriminant analysis

    Energy Technology Data Exchange (ETDEWEB)

    Burr, T.; Doak, J.

    1997-05-01

    This report describes our experience in implementing a non-parametric (distribution-free) discriminant analysis module for use in a wide range of pattern recognition problems. Issues discussed include performance results on both real and simulated data sets, comparisons to other methods, and the computational environment. In some cases, this module performs better than other existing methods. Nearly all cases can benefit from the application of multiple methods.

  4. A Trivial Linear Discriminant Function

    Directory of Open Access Journals (Sweden)

    Shuichi Shinmura

    2015-11-01

    Full Text Available In this paper, we focus on the new model selection procedure of the discriminant analysis. Combining re-sampling technique with k-fold cross validation, we develop a k-fold cross validation for small sample method. By this breakthrough, we obtain the mean error rate in the validation samples (M2 and the 95\\% confidence interval (CI of discriminant coefficient. Moreover, we propose the model  selection  procedure  in  which  the model having a minimum M2 was  chosen  to  the  best  model.  We  apply  this  new  method and procedure to the pass/ fail determination of  exam  scores.  In  this  case,  we  fix  the constant =1 for seven linear discriminant  functions  (LDFs  and  several  good  results  were obtained as follows: 1 M2 of Fisher's LDF are over 4.6\\% worse than Revised IP-OLDF. 2 A soft-margin  SVM  for  penalty c=1  (SVM1  is  worse  than  another  mathematical  programming (MP based LDFs and logistic regression . 3 The 95\\% CI of the best discriminant coefficients was obtained. Seven LDFs except for Fisher's LDF are almost the same as a trivial LDF for the linear separable model. Furthermore, if we choose the median of the coefficient of seven LDFs except for Fisher's LDF,  those are almost the same as the trivial LDF for the linear separable model.

  5. Competition, Takeovers and Gender Discrimination

    OpenAIRE

    Heyman, Fredrik; Svaleryd, Helena; Vlachos, Jonas

    2008-01-01

    Theories of taste-based discrimination predict that competitive pressures will drive discriminatory behaviour out of the market. Using detailed matched employer-employee data, we analyze how firm takeovers and product market competition are related to the gender composition of the firm’s workforce and the gender wage gap. Using a difference-in-difference framework and dealing with several endogeneity concerns, we find that the share of female employees increases as a result of an ownership ch...

  6. Social Hierarchies, Prejudice, and Discrimination

    OpenAIRE

    Snellman, Alexandra

    2007-01-01

    This thesis is based on three papers where I examine some aspects of ethnic and gender-based prejudice and discrimination in hierarchical situations. In Paper I, the existence of ethnic hierarchies in Sweden is explored. Both immigrant and ethnic Swedes were asked to report their social distance to a number of ethnic groups represented in their geographical area. The results showed that hierarchies exist in Swedish environments and that they are connected with both ethnic prejudice and partic...

  7. Rationing-Based Price Discrimination

    OpenAIRE

    Ruhai Wu; Xianjun Geng; Andrew B. Whinston

    2006-01-01

    This paper provides a theory of rationing where rationing functions as an effective mechanism for second degree price discrimination by a monopoly seller. When a seller charges multiple prices on homogenous products to all consumers, supply at the lowest price is limited and rationed among consumers. The supply shortage differentiates products sold at the lowest price and those sold at a higher price. When high-valuation consumers identify themselves at the higher price, the seller may extrac...

  8. Sex Discrimination in Uncertain Times

    OpenAIRE

    Thornton, Margaret

    2010-01-01

    This collection of essays arose from a conference held to mark the silver anniversary of the Australian Sex Discrimination Act (1984). The collection has two aims: first; to honour the contributions of both the spirited individuals who valiantly fought for the enactment of the legislation against the odds, and those who championed the new law once it was passed; secondly, to present a stock-take of the Act within the changed socio-political environment of the 21st century. The contributor...

  9. Variations in students' perceived reasons for, sources of, and forms of in-school discrimination: A latent class analysis.

    Science.gov (United States)

    Byrd, Christy M; Carter Andrews, Dorinda J

    2016-08-01

    Although there exists a healthy body of literature related to discrimination in schools, this research has primarily focused on racial or ethnic discrimination as perceived and experienced by students of color. Few studies examine students' perceptions of discrimination from a variety of sources, such as adults and peers, their descriptions of the discrimination, or the frequency of discrimination in the learning environment. Middle and high school students in a Midwestern school district (N=1468) completed surveys identifying whether they experienced discrimination from seven sources (e.g., peers, teachers, administrators), for seven reasons (e.g., gender, race/ethnicity, religion), and in eight forms (e.g., punished more frequently, called names, excluded from social groups). The sample was 52% White, 15% Black/African American, 14% Multiracial, and 17% Other. Latent class analysis was used to cluster individuals based on reported sources of, reasons for, and forms of discrimination. Four clusters were found, and ANOVAs were used to test for differences between clusters on perceptions of school climate, relationships with teachers, perceptions that the school was a "good school," and engagement. The Low Discrimination cluster experienced the best outcomes, whereas an intersectional cluster experienced the most discrimination and the worst outcomes. The results confirm existing research on the negative effects of discrimination. Additionally, the paper adds to the literature by highlighting the importance of an intersectional approach to examining students' perceptions of in-school discrimination. Copyright © 2016 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

  10. Artificial Skin Ridges Enhance Local Tactile Shape Discrimination

    Directory of Open Access Journals (Sweden)

    Shuzhi Sam Ge

    2011-09-01

    Full Text Available One of the fundamental requirements for an artificial hand to successfully grasp and manipulate an object is to be able to distinguish different objects’ shapes and, more specifically, the objects’ surface curvatures. In this study, we investigate the possibility of enhancing the curvature detection of embedded tactile sensors by proposing a ridged fingertip structure, simulating human fingerprints. In addition, a curvature detection approach based on machine learning methods is proposed to provide the embedded sensors with the ability to discriminate the surface curvature of different objects. For this purpose, a set of experiments were carried out to collect tactile signals from a 2 × 2 tactile sensor array, then the signals were processed and used for learning algorithms. To achieve the best possible performance for our machine learning approach, three different learning algorithms of Naïve Bayes (NB, Artificial Neural Networks (ANN, and Support Vector Machines (SVM were implemented and compared for various parameters. Finally, the most accurate method was selected to evaluate the proposed skin structure in recognition of three different curvatures. The results showed an accuracy rate of 97.5% in surface curvature discrimination.

  11. Sparsity Preserving Discriminant Projections with Applications to Face Recognition

    Directory of Open Access Journals (Sweden)

    Yingchun Ren

    2016-01-01

    Full Text Available Dimensionality reduction is extremely important for understanding the intrinsic structure hidden in high-dimensional data. In recent years, sparse representation models have been widely used in dimensionality reduction. In this paper, a novel supervised learning method, called Sparsity Preserving Discriminant Projections (SPDP, is proposed. SPDP, which attempts to preserve the sparse representation structure of the data and maximize the between-class separability simultaneously, can be regarded as a combiner of manifold learning and sparse representation. Specifically, SPDP first creates a concatenated dictionary by classwise PCA decompositions and learns the sparse representation structure of each sample under the constructed dictionary using the least square method. Secondly, a local between-class separability function is defined to characterize the scatter of the samples in the different submanifolds. Then, SPDP integrates the learned sparse representation information with the local between-class relationship to construct a discriminant function. Finally, the proposed method is transformed into a generalized eigenvalue problem. Extensive experimental results on several popular face databases demonstrate the feasibility and effectiveness of the proposed approach.

  12. A discrimination problem from seismology

    International Nuclear Information System (INIS)

    Elvers, E.

    1975-12-01

    Seismic discrimination between earthquakes and underground nuclear explosions is studied, utilizing magnitudes of two kinds from several seismic stations. A model is given first, where the mean values of the magnitudes are linear fuctions of a parameter describing event size. It is shown how the model parameters can be estimated after a minor restriction on their space. When the discrimination rule is derived from the model, a few different approaches are considered, and they are shown to coincide. It is found reasonabel to use a discriminant, which is linear in the magnitudes, and explicit formulas are obtained. The power of the method is expressed by a measure of separation between the alternatives, which also shows the importance of the individual magnitudes. Missing data is a frequent problem in practice, and the case is treated where there is a detection threshold for one of the magnitudes. The classicfication probabilities are computed when applying the rule to the available magnitudes, and they depend on the event size. The method is not optimal, and it is shown that it can be improved by using the technique of identification by negative evidence, i.e. by utilizing the threshold as upper bound for a missing magnitude. The model is one of general use, and the results thus have a wider applicability. (author)

  13. Color discrimination with broadband photoreceptors.

    Science.gov (United States)

    Schnaitmann, Christopher; Garbers, Christian; Wachtler, Thomas; Tanimoto, Hiromu

    2013-12-02

    Color vision is commonly assumed to rely on photoreceptors tuned to narrow spectral ranges. In the ommatidium of Drosophila, the four types of so-called inner photoreceptors express different narrow-band opsins. In contrast, the outer photoreceptors have a broadband spectral sensitivity and were thought to exclusively mediate achromatic vision. Using computational models and behavioral experiments, we demonstrate that the broadband outer photoreceptors contribute to color vision in Drosophila. The model of opponent processing that includes the opsin of the outer photoreceptors scored the best fit to wavelength discrimination data. To experimentally uncover the contribution of individual photoreceptor types, we restored phototransduction of targeted photoreceptor combinations in a blind mutant. Dichromatic flies with only broadband photoreceptors and one additional receptor type can discriminate different colors, indicating the existence of a specific output comparison of the outer and inner photoreceptors. Furthermore, blocking interneurons postsynaptic to the outer photoreceptors specifically impaired color but not intensity discrimination. Our findings show that receptors with a complex and broad spectral sensitivity can contribute to color vision and reveal that chromatic and achromatic circuits in the fly share common photoreceptors. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. 29 CFR 34.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Discrimination prohibited. 34.3 Section 34.3 Labor Office of... THE JOB TRAINING PARTNERSHIP ACT OF 1982, AS AMENDED (JTPA) General Provisions § 34.3 Discrimination... participation in JTPA, be excluded from participation in, denied the benefits of, subjected to discrimination...

  15. 38 CFR 18.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Discrimination prohibited... THE CIVIL RIGHTS ACT OF 1964 General § 18.3 Discrimination prohibited. (a) General. No person in the..., be denied the benefits of, or be otherwise subjected to discrimination under any program to which...

  16. 49 CFR 21.5 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Discrimination prohibited. 21.5 Section 21.5... DEPARTMENT OF TRANSPORTATION-EFFECTUATION OF TITLE VI OF THE CIVIL RIGHTS ACT OF 1964 § 21.5 Discrimination... discrimination under, any program to which this part applies. (b) Specific discriminatory actions prohibited: (1...

  17. 13 CFR 112.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Discrimination prohibited. 112.3... ASSISTED PROGRAMS OF SBA-EFFECTUATION OF TITLE VI OF THE CIVIL RIGHTS ACT OF 1964 § 112.3 Discrimination... be otherwise subjected to discrimination by any business or other activity. (b) Specific...

  18. 7 CFR 15b.17 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Discrimination prohibited. 15b.17 Section 15b.17... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Accessibility § 15b.17 Discrimination prohibited. No... to discrimination under any program or activity receiving assistance from this Department. ...

  19. 45 CFR 84.11 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Discrimination prohibited. 84.11 Section 84.11... § 84.11 Discrimination prohibited. (a) General. (1) No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity to which this...

  20. 50 CFR 3.1 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Discrimination prohibited. 3.1 Section 3.1... PROVISIONS NONDISCRIMINATION-CONTRACTS, PERMITS, AND USE OF FACILITIES § 3.1 Discrimination prohibited. No..., be denied the benefits of, or be otherwise subjected to any form of discrimination or segregation...

  1. 22 CFR 217.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Discrimination prohibited. 217.4 Section 217.4... PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE General Provisions § 217.4 Discrimination... participation in, be denied the benefits of, or otherwise be subjected to discrimination under any program or...

  2. 45 CFR 1203.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Discrimination prohibited. 1203.4 Section 1203.4... OF 1964 § 1203.4 Discrimination prohibited. (a) General. A person in the United States shall not, on... benefits of, or be otherwise subjected to discrimination under, a program to which this part applies. (b...

  3. 43 CFR 34.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Discrimination prohibited. 34.4 Section 34... DURING CONSTRUCTION AND OPERATION OF THE ALASKA NATURAL GAS TRANSPORTATION SYSTEM § 34.4 Discrimination... part applies. (b) Specific actions in which discrimination is prohibited. No person shall directly or...

  4. 45 CFR 1110.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Discrimination prohibited. 1110.3 Section 1110.3... HUMANITIES GENERAL NONDISCRIMINATION IN FEDERALLY ASSISTED PROGRAMS § 1110.3 Discrimination prohibited. (a... from participation in, be denied the benefits of, or be otherwise subjected, to discrimination under...

  5. 24 CFR 8.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Discrimination prohibited. 8.4... DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT General Provisions § 8.4 Discrimination prohibited. (a) No... in, be denied the benefits of, or otherwise be subjected to discrimination under any program or...

  6. 29 CFR 32.12 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Discrimination prohibited. 32.12 Section 32.12 Labor Office... § 32.12 Discrimination prohibited. (a) General. (1) No qualified handicapped individual shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity to which...

  7. 6 CFR 21.5 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 6 Domestic Security 1 2010-01-01 2010-01-01 false Discrimination prohibited. 21.5 Section 21.5... FROM THE DEPARTMENT OF HOMELAND SECURITY § 21.5 Discrimination prohibited. (a) General. No person in... participation in, be denied the benefits of, or be otherwise subjected to discrimination under, any program to...

  8. 14 CFR 380.26 - Discrimination.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Discrimination. 380.26 Section 380.26... REGULATIONS PUBLIC CHARTERS Requirements Applicable to Charter Operators § 380.26 Discrimination. No charter... unjust discrimination or any undue or unreasonable prejudice or disadvantage in any respect whatsoever. ...

  9. 43 CFR 17.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Discrimination prohibited. 17.3 Section 17... National Origin § 17.3 Discrimination prohibited. (a) General. No person in the United States shall, on the..., or be otherwise subjected to discrimination under any program to which this part applies. (b...

  10. 18 CFR 705.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Discrimination... Discrimination prohibited. (a) General. No person in the United States shall, on the grounds of race, color, or... discrimination under, any program to which this part applies. (b) Specific discriminatory actions prohibited. (1...

  11. 18 CFR 1307.5 - Employment discrimination.

    Science.gov (United States)

    2010-04-01

    ... discrimination. 1307.5 Section 1307.5 Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY NONDISCRIMINATION WITH RESPECT TO HANDICAP § 1307.5 Employment discrimination. (a) General. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or...

  12. 13 CFR 113.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Discrimination prohibited. 113.3... Provisions § 113.3 Discrimination prohibited. To the extent not covered or prohibited by part 112 of this... employment decisions shall be made in a manner which ensures that discrimination on the basis of handicap...

  13. 15 CFR 8.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Discrimination prohibited. 8.4 Section... General Provisions; Prohibitions: Nondiscrimination Clause; Applicability to Programs § 8.4 Discrimination... discrimination under, any program to which this part applies. (b) Specific discriminatory acts prohibited. (1) A...

  14. Discrimination ability of the Energy score

    DEFF Research Database (Denmark)

    Pinson, Pierre; Tastu, Julija

    as appealing since being proper, we show that its discrimination ability may be limited when focusing on the dependence structure of multivariate probabilistic forecasts. For the case of multivariate Gaussian process, a theoretical upper for such discrimination ability is derived and discussed. This limited...... discrimination ability may eventually get compromised by computational and sampling issues, as dimension increases....

  15. 29 CFR 502.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Discrimination prohibited. 502.3 Section 502.3 Labor... IMMIGRATION AND NATIONALITY ACT (SUSPENDED 6-29-2009) General Provisions § 502.3 Discrimination prohibited. (a... Department regulation promulgated pursuant to sec. 218 of the INA. (b) Allegations of discrimination against...

  16. 45 CFR 605.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Discrimination prohibited. 605.4 Section 605.4... Provisions § 605.4 Discrimination prohibited. (a) General. No qualified handicapped person shall, on the... subjected to discrimination under any program or activity which receives Federal financial assistance. (b...

  17. 43 CFR 27.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Discrimination prohibited. 27.3 Section 27... ISSUED UNDER TITLE II OF PUBLIC LAW 93-153 § 27.3 Discrimination prohibited. (a) General. No person shall... through contractual or other arrangements, subject an individual to discrimination on the grounds of race...

  18. 45 CFR 605.11 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Discrimination prohibited. 605.11 Section 605.11... Employment Practices § 605.11 Discrimination prohibited. (a) General. (1) No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or...

  19. 45 CFR 605.21 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Discrimination prohibited. 605.21 Section 605.21... Accessibility § 605.21 Discrimination prohibited. No qualified handicapped person shall, because a recipient's... from participation in, or otherwise be subjected to discrimination under any program or activity to...

  20. 14 CFR 372.22 - Discrimination.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Discrimination. 372.22 Section 372.22... REGULATIONS OVERSEAS MILITARY PERSONNEL CHARTERS Conditions and Limitations § 372.22 Discrimination. No... any unjust discrimination or any undue or unreasonable prejudice or disadvantage in any respect...

  1. 22 CFR 141.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Discrimination prohibited. 141.3 Section 141.3... DEPARTMENT OF STATE-EFFECTUATION OF TITLE VI OF THE CIVIL RIGHTS ACT OF 1964 § 141.3 Discrimination... discrimination under any program to which this part applies. (b) Specific discriminatory actions prohibited. (1...

  2. 34 CFR 100.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Discrimination prohibited. 100.3 Section 100.3... EFFECTUATION OF TITLE VI OF THE CIVIL RIGHTS ACT OF 1964 § 100.3 Discrimination prohibited. (a) General. No... participation in, be denied the benefits of, or be otherwise subjected to discrimination under any program to...

  3. 29 CFR 32.26 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Discrimination prohibited. 32.26 Section 32.26 Labor Office... RECEIVING FEDERAL FINANCIAL ASSISTANCE Accessibility § 32.26 Discrimination prohibited. No qualified... discrimination under any program or activity to which this part applies. ...

  4. 24 CFR 1.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Discrimination prohibited. 1.4... DEVELOPMENT-EFFECTUATION OF TITLE VI OF THE CIVIL RIGHTS ACT OF 1964 § 1.4 Discrimination prohibited. (a... excluded from participation in, be denied the benefits of, or be otherwise subjected to discrimination...

  5. 45 CFR 80.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Discrimination prohibited. 80.3 Section 80.3... TITLE VI OF THE CIVIL RIGHTS ACT OF 1964 § 80.3 Discrimination prohibited. (a) General. No person in the..., be denied the benefits of, or be otherwise subjected to discrimination under any program to which...

  6. 15 CFR 8b.11 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Discrimination prohibited. 8b.11 Section 8b.11 Commerce and Foreign Trade Office of the Secretary of Commerce PROHIBITION OF DISCRIMINATION... Practices § 8b.11 Discrimination prohibited. (a) General. (1) No qualified handicapped individual shall, on...

  7. 43 CFR 17.203 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Discrimination prohibited. 17.203 Section... Discrimination prohibited. (a) General. No qualified handicapped person shall, on the basis of handicap, be excluded from participation in, be denied the benefits of, or otherwise be subjected to discrimination...

  8. 34 CFR 104.11 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Discrimination prohibited. 104.11 Section 104.11... ASSISTANCE Employment Practices § 104.11 Discrimination prohibited. (a) General. (1) No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or...

  9. 22 CFR 209.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Discrimination prohibited. 209.4 Section 209.4 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT NON-DISCRIMINATION IN FEDERALLY-ASSISTED PROGRAMS... § 209.4 Discrimination prohibited. (a) General. No person in the United States shall, on the grounds of...

  10. 45 CFR 84.21 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Discrimination prohibited. 84.21 Section 84.21... Discrimination prohibited. No qualified handicapped person shall, because a recipient's facilities are... in, or otherwise be subjected to discrimination under any program or activity to which this part...

  11. 29 CFR 501.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Discrimination prohibited. 501.4 Section 501.4 Labor... IMMIGRATION AND NATIONALITY ACT General Provisions § 501.4 Discrimination prohibited. (a) A person may not... discrimination against any person under paragraph (a) of this section will be investigated by the WHD. Where the...

  12. 7 CFR 15b.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Discrimination prohibited. 15b.4 Section 15b.4... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE General Provisions § 15b.4 Discrimination prohibited. (a... in, be denied the benefits of, or otherwise be subjected to discrimination under any program or...

  13. 29 CFR 32.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Discrimination prohibited. 32.4 Section 32.4 Labor Office of... FEDERAL FINANCIAL ASSISTANCE General Provisions § 32.4 Discrimination prohibited. (a) General. No... denied the benefits of, or otherwise be subjected to discrimination under any program or activity which...

  14. 14 CFR 271.9 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Discrimination prohibited. 271.9 Section... TRANSPORTATION § 271.9 Discrimination prohibited. (a) All air carriers receiving subsidy under this part shall comply with the following: (1) The Age Discrimination Act of 1975; (2) The Civil Rights Act of 1964 and...

  15. 45 CFR 84.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Discrimination prohibited. 84.4 Section 84.4... § 84.4 Discrimination prohibited. (a) General. No qualified handicapped person shall, on the basis of... discrimination under any program or activity which receives Federal financial assistance. (b) Discriminatory...

  16. 15 CFR 8b.16 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Discrimination prohibited. 8b.16 Section 8b.16 Commerce and Foreign Trade Office of the Secretary of Commerce PROHIBITION OF DISCRIMINATION... Accessibility § 8b.16 Discrimination prohibited. No qualified handicapped individual shall, because a recipient...

  17. 49 CFR 27.7 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Discrimination prohibited. 27.7 Section 27.7... OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE General § 27.7 Discrimination prohibited. (a... participation in, be denied the benefits of, or otherwise be subjected to discrimination under any program or...

  18. 10 CFR 19.32 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Discrimination prohibited. 19.32 Section 19.32 Energy... § 19.32 Discrimination prohibited. No person shall on the grounds of sex be excluded from participation in, be denied a license, be denied the benefit of, or be subjected to discrimination under any...

  19. 45 CFR 611.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Discrimination prohibited. 611.3 Section 611.3... CIVIL RIGHTS ACT OF 1964 § 611.3 Discrimination prohibited. (a) General. No person in the United States... benefits of, or be otherwise subjected to discrimination under any program to which this part applies. (b...

  20. 7 CFR 15b.12 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Discrimination prohibited. 15b.12 Section 15b.12... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Employment Practices § 15b.12 Discrimination prohibited. (a... discrimination in employment under any program or activity receiving assistance from this Department. (2) A...

  1. Experienced discrimination amongst European old citizens

    NARCIS (Netherlands)

    van den Heuvel, Wim J. A.; van Santvoort, Marc M.

    2011-01-01

    This study analyses the experienced age discrimination of old European citizens and the factors related to this discrimination. Differences in experienced discrimination between old citizens of different European countries are explored. Data from the 2008 ESS survey are used. Old age is defined as

  2. 24 CFR 6.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Discrimination prohibited. 6.4... COMMUNITY DEVELOPMENT ACT OF 1974 General Provisions § 6.4 Discrimination prohibited. (a) Section 109... benefits of, or be subjected to discrimination under any program or activity funded in whole or in part...

  3. 5 CFR 950.110 - Prohibited discrimination.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Prohibited discrimination. 950.110 Section 950.110 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE... PRIVATE VOLUNTARY ORGANIZATIONS General Provisions § 950.110 Prohibited discrimination. Discrimination for...

  4. 15 CFR 8b.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Discrimination prohibited. 8b.4 Section 8b.4 Commerce and Foreign Trade Office of the Secretary of Commerce PROHIBITION OF DISCRIMINATION... Provisions § 8b.4 Discrimination prohibited. (a) General. No qualified handicapped individual shall, on the...

  5. 7 CFR 15d.2 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Discrimination prohibited. 15d.2 Section 15d.2... THE UNITED STATES DEPARTMENT OF AGRICULTURE § 15d.2 Discrimination prohibited. (a) No agency, officer... participation in, deny the benefits of, or subject to discrimination any person in the United States under any...

  6. 22 CFR 142.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Discrimination prohibited. 142.4 Section 142.4... OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE General Provisions § 142.4 Discrimination... participation in, be denied the benefits of, or otherwise be subjected to discrimination under any program or...

  7. 34 CFR 104.21 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Discrimination prohibited. 104.21 Section 104.21... ASSISTANCE Accessibility § 104.21 Discrimination prohibited. No qualified handicapped person shall, because a... excluded from participation in, or otherwise be subjected to discrimination under any program or activity...

  8. 34 CFR 104.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Discrimination prohibited. 104.4 Section 104.4... ASSISTANCE General Provisions § 104.4 Discrimination prohibited. (a) General. No qualified handicapped person... otherwise be subjected to discrimination under any program or activitiy which receives Federal financial...

  9. 29 CFR 500.9 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Discrimination prohibited. 500.9 Section 500.9 Labor... SEASONAL AGRICULTURAL WORKER PROTECTION General Provisions § 500.9 Discrimination prohibited. (a) It is a... Secretary alleging such discrimination. ...

  10. 38 CFR 18.404 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Discrimination prohibited... Provisions § 18.404 Discrimination prohibited. (a) General. No qualified handicapped person shall, on the... subjected to discrimination under any program or activity which receives Federal financial assistance. (b...

  11. 28 CFR 42.203 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Discrimination prohibited. 42.203 Section...) of the Justice System Improvement Act of 1979 § 42.203 Discrimination prohibited. (a) No person in... participation in, be denied the benefits of, be subjected to discrimination under, or denied employment in...

  12. 28 CFR 42.510 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Discrimination prohibited. 42.510 Section...-Implementation of Section 504 of the Rehabilitation Act of 1973 Employment § 42.510 Discrimination prohibited. (a) General. (1) No qualified handicapped person shall on the basis of handicap be subjected to discrimination...

  13. 38 CFR 18.421 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Discrimination prohibited... Accessibility § 18.421 Discrimination prohibited. No qualified handicapped person shall, because a recipient's... from participation in, or otherwise be subjected to discrimination under any program or activity to...

  14. 28 CFR 42.520 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Discrimination prohibited. 42.520 Section...-Implementation of Section 504 of the Rehabilitation Act of 1973 Accessibility § 42.520 Discrimination prohibited... participation in, or otherwise subjected to discrimination under any program or activity receiving Federal...

  15. 28 CFR 35.149 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Discrimination prohibited. 35.149 Section... STATE AND LOCAL GOVERNMENT SERVICES Program Accessibility § 35.149 Discrimination prohibited. Except as... subjected to discrimination by any public entity. ...

  16. 28 CFR 42.503 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Discrimination prohibited. 42.503 Section...-Implementation of Section 504 of the Rehabilitation Act of 1973 General Provisions § 42.503 Discrimination... from participation in, be denied the benefits of, or otherwise be subjected to discrimination under any...

  17. 29 CFR 1630.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Discrimination prohibited. 1630.4 Section 1630.4 Labor... EQUAL EMPLOYMENT PROVISIONS OF THE AMERICANS WITH DISABILITIES ACT § 1630.4 Discrimination prohibited..., or privilege of employment. The term discrimination includes, but is not limited to, the acts...

  18. 18 CFR 1307.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Discrimination... NONDISCRIMINATION WITH RESPECT TO HANDICAP § 1307.4 Discrimination prohibited. (a) General. No qualified handicapped... otherwise be subjected to discrimination under any program or activity to which this part applies. (b...

  19. Simultaneous Visual Discrimination in Asian Elephants

    Science.gov (United States)

    Nissani, Moti; Hoefler-Nissani, Donna; Lay, U. Tin; Htun, U. Wan

    2005-01-01

    Two experiments explored the behavior of 20 Asian elephants ("Elephas aximus") in simultaneous visual discrimination tasks. In Experiment 1, 7 Burmese logging elephants acquired a white+/black- discrimination, reaching criterion in a mean of 2.6 sessions and 117 discrete trials, whereas 4 elephants acquired a black+/white- discrimination in 5.3…

  20. Non-discrimination and equality of women

    NARCIS (Netherlands)

    Oostland, Rolanda Carina

    2006-01-01

    Non-discrimination is considered to be a cornerstone of the human rights framework of the United Nations. Already in the UN Charter of 1945 it is stated that human rights should be promoted without discrimination as to, amongst other things, sex. This principle of non-discrimination on the ground of

  1. Third-Degree Price Discrimination Revisited

    Science.gov (United States)

    Kwon, Youngsun

    2006-01-01

    The author derives the probability that price discrimination improves social welfare, using a simple model of third-degree price discrimination assuming two independent linear demands. The probability that price discrimination raises social welfare increases as the preferences or incomes of consumer groups become more heterogeneous. He derives the…

  2. 10 CFR 1040.71 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Discrimination prohibited. 1040.71 Section 1040.71 Energy... § 1040.71 Discrimination prohibited. No handicapped person shall, because a recipient's facilities are... in, or be subjected to discrimination under any program or activity that receives or benefits from...

  3. 45 CFR 1151.21 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Discrimination prohibited. 1151.21 Section 1151.21... HUMANITIES NATIONAL ENDOWMENT FOR THE ARTS NONDISCRIMINATION ON THE BASIS OF HANDICAP Discrimination Prohibited Accessibility § 1151.21 Discrimination prohibited. No qualified handicapped person shall, because...

  4. 24 CFR 232.625 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Discrimination prohibited. 232.625... Fire Safety Equipment Special Requirements § 232.625 Discrimination prohibited. Any contract or... provide that there shall be no discrimination against any employee or applicant for employment because of...

  5. 14 CFR 1251.200 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Discrimination prohibited. 1251.200 Section... OF HANDICAP Employment Practices § 1251.200 Discrimination prohibited. (a) General. (1) No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any...

  6. 45 CFR 1170.31 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Discrimination prohibited. 1170.31 Section 1170.31... ASSISTED PROGRAMS OR ACTIVITIES Accessibility § 1170.31 Discrimination prohibited. No qualified handicapped... denied the benefits of, be excluded from participation in, or otherwise be subjected to discrimination...

  7. 10 CFR 1040.63 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Discrimination prohibited. 1040.63 Section 1040.63 Energy... Provisions § 1040.63 Discrimination prohibited. (a) General. No qualified handicapped person shall, on the... subjected to discrimination under any program or activity that receives Federal financial assistance from...

  8. 10 CFR 1040.13 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Discrimination prohibited. 1040.13 Section 1040.13 Energy..., as Amended; and Section 401 of the Energy Reorganization Act of 1974 § 1040.13 Discrimination... benefits of, or be otherwise subjected to discrimination under any program to which this subpart applies...

  9. 5 CFR 900.404 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Discrimination prohibited. 900.404... § 900.404 Discrimination prohibited. (a) General. A person in the United States shall not, on the ground... be otherwise subjected to discrimination under, a program to which this subpart applies. (b) Specific...

  10. 14 CFR 1251.103 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Discrimination prohibited. 1251.103 Section... OF HANDICAP General Provisions § 1251.103 Discrimination prohibited. (a) General. No qualified... of, or otherwise be subjected to discrimination under any program or activity which receives Federal...

  11. 22 CFR 217.21 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Discrimination prohibited. 217.21 Section 217... Discrimination prohibited. No qualified handicapped person shall, because a recipient's facilities within the... excluded from participation in, or otherwise be subjected to discrimination under any program or activity...

  12. 22 CFR 142.15 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Discrimination prohibited. 142.15 Section 142... PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Accessibility § 142.15 Discrimination... be subjected to discrimination under any program or activity to which the part applies. ...

  13. 5 CFR 900.704 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Discrimination prohibited. 900.704... Federally Assisted Programs of the Office of Personnel Management § 900.704 Discrimination prohibited. (a..., be denied the benefits of, or otherwise be subjected to discrimination under any program or activity...

  14. 14 CFR 1251.300 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Discrimination prohibited. 1251.300 Section... OF HANDICAP Accessibility § 1251.300 Discrimination prohibited. No qualified handicapped person shall... benefits of, be excluded from participation in, or otherwise be subjected to discrimination under any...

  15. Discrimination against Students in Higher Education.

    Science.gov (United States)

    Pieronek, Catherine

    2002-01-01

    Surveys courts cases in 2000 that addressed discrimination against students, including gender discrimination under Title IX and racial discrimination under Title VI. The cases return to familiar themes, exploring when, if ever, an educational institution may consider gender or race in making decisions that affect the educational opportunities…

  16. Varieties of perceptual learning.

    Science.gov (United States)

    Mackintosh, N J

    2009-05-01

    Although most studies of perceptual learning in human participants have concentrated on the changes in perception assumed to be occurring, studies of nonhuman animals necessarily measure discrimination learning and generalization and remain agnostic on the question of whether changes in behavior reflect changes in perception. On the other hand, animal studies do make it easier to draw a distinction between supervised and unsupervised learning. Differential reinforcement will surely teach animals to attend to some features of a stimulus array rather than to others. But it is an open question as to whether such changes in attention underlie the enhanced discrimination seen after unreinforced exposure to such an array. I argue that most instances of unsupervised perceptual learning observed in animals (and at least some in human animals) are better explained by appeal to well-established principles and phenomena of associative learning theory: excitatory and inhibitory associations between stimulus elements, latent inhibition, and habituation.

  17. Visual Tracking via Feature Tensor Multimanifold Discriminate Analysis

    Directory of Open Access Journals (Sweden)

    Ting-quan Deng

    2014-01-01

    Full Text Available In the visual tracking scenarios, if there are multiple objects, due to the interference of similar objects, tracking may fail in the progress of occlusion to separation. To address this problem, this paper proposed a visual tracking algorithm with discrimination through multimanifold learning. Color-gradient-based feature tensor was used to describe object appearance for accommodation of partial occlusion. A prior multimanifold tensor dataset is established through the template matching tracking algorithm. For the purpose of discrimination, tensor distance was defined to determine the intramanifold and intermanifold neighborhood relationship in multimanifold space. Then multimanifold discriminate analysis was employed to construct multilinear projection matrices of submanifolds. Finally, object states were obtained by combining with sequence inference. Meanwhile, the multimanifold dataset and manifold learning embedded projection should be updated online. Experiments were conducted on two real visual surveillance sequences to evaluate the proposed algorithm with three state-of-the-art tracking methods qualitatively and quantitatively. Experimental results show that the proposed algorithm can achieve effective and robust effect in multi-similar-object mutual occlusion scenarios.

  18. Early learners' discrimination of second-language vowels.

    Science.gov (United States)

    Højen, Anders; Flege, James E

    2006-05-01

    It is uncertain from previous research to what extent the perceptual system retains plasticity after attunement to the native language (L1) sound system. This study evaluated second-language (L2) vowel discrimination by individuals who began learning the L2 as children ("early learners"). Experiment 1 identified procedures that lowered discrimination scores for foreign vowel contrasts in an AXB test (with three physically different stimuli per trial, where "X" was drawn from the same vowel category as "A" or "B"). Experiment 2 examined the AXB discrimination of English vowels by native Spanish early learners and monolingual speakers of Spanish and English (20 per group) at interstimulus intervals (ISIs) of 1000 and 0 ms. The Spanish monolinguals obtained near-chance scores for three difficult vowel contrasts, presumably because they did not perceive the vowels as distinct phonemes and because the experimental design hindered low-level encoding strategies. Like the English monolinguals, the early learners obtained high scores, indicating they had shown considerable perceptual learning. However, statistically significant differences between early learners and English monolinguals for two of three difficult contrasts at the 0-ms ISI suggested that their underlying perceptual systems were not identical. Implications for claims regarding perceptual plasticity following L1 attunement are discussed.

  19. Inter-class sparsity based discriminative least square regression.

    Science.gov (United States)

    Wen, Jie; Xu, Yong; Li, Zuoyong; Ma, Zhongli; Xu, Yuanrong

    2018-02-21

    Least square regression is a very popular supervised classification method. However, two main issues greatly limit its performance. The first one is that it only focuses on fitting the input features to the corresponding output labels while ignoring the correlations among samples. The second one is that the used label matrix, i.e., zero-one label matrix is inappropriate for classification. To solve these problems and improve the performance, this paper presents a novel method, i.e., inter-class sparsity based discriminative least square regression (ICS_DLSR), for multi-class classification. Different from other methods, the proposed method pursues that the transformed samples have a common sparsity structure in each class. For this goal, an inter-class sparsity constraint is introduced to the least square regression model such that the margins of samples from the same class can be greatly reduced while those of samples from different classes can be enlarged. In addition, an error term with row-sparsity constraint is introduced to relax the strict zero-one label matrix, which allows the method to be more flexible in learning the discriminative transformation matrix. These factors encourage the method to learn a more compact and discriminative transformation for regression and thus has the potential to perform better than other methods. Extensive experimental results show that the proposed method achieves the best performance in comparison with other methods for multi-class classification. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Discriminative exemplar coding for sign language recognition with Kinect.

    Science.gov (United States)

    Sun, Chao; Zhang, Tianzhu; Bao, Bing-Kun; Xu, Changsheng; Mei, Tao

    2013-10-01

    Sign language recognition is a growing research area in the field of computer vision. A challenge within it is to model various signs, varying with time resolution, visual manual appearance, and so on. In this paper, we propose a discriminative exemplar coding (DEC) approach, as well as utilizing Kinect sensor, to model various signs. The proposed DEC method can be summarized as three steps. First, a quantity of class-specific candidate exemplars are learned from sign language videos in each sign category by considering their discrimination. Then, every video of all signs is described as a set of similarities between frames within it and the candidate exemplars. Instead of simply using a heuristic distance measure, the similarities are decided by a set of exemplar-based classifiers through the multiple instance learning, in which a positive (or negative) video is treated as a positive (or negative) bag and those frames similar to the given exemplar in Euclidean space as instances. Finally, we formulate the selection of the most discriminative exemplars into a framework and simultaneously produce a sign video classifier to recognize sign. To evaluate our method, we collect an American sign language dataset, which includes approximately 2000 phrases, while each phrase is captured by Kinect sensor with color, depth, and skeleton information. Experimental results on our dataset demonstrate the feasibility and effectiveness of the proposed approach for sign language recognition.

  1. Discrimination of inflammatory bowel disease using Raman spectroscopy and linear discriminant analysis methods

    Science.gov (United States)

    Ding, Hao; Cao, Ming; DuPont, Andrew W.; Scott, Larry D.; Guha, Sushovan; Singhal, Shashideep; Younes, Mamoun; Pence, Isaac; Herline, Alan; Schwartz, David; Xu, Hua; Mahadevan-Jansen, Anita; Bi, Xiaohong

    2016-03-01

    Inflammatory bowel disease (IBD) is an idiopathic disease that is typically characterized by chronic inflammation of the gastrointestinal tract. Recently much effort has been devoted to the development of novel diagnostic tools that can assist physicians for fast, accurate, and automated diagnosis of the disease. Previous research based on Raman spectroscopy has shown promising results in differentiating IBD patients from normal screening cases. In the current study, we examined IBD patients in vivo through a colonoscope-coupled Raman system. Optical diagnosis for IBD discrimination was conducted based on full-range spectra using multivariate statistical methods. Further, we incorporated several feature selection methods in machine learning into the classification model. The diagnostic performance for disease differentiation was significantly improved after feature selection. Our results showed that improved IBD diagnosis can be achieved using Raman spectroscopy in combination with multivariate analysis and feature selection.

  2. Workplace discrimination: experiences of practicing physicians.

    Science.gov (United States)

    Coombs, Alice A Tolbert; King, Roderick K

    2005-04-01

    In response to a growing concern regarding physician discrimination in the workplace, this study was developed to: (1) describe the types of discrimination that exist for the practicing physician and (2) determine which groups of physicians are more likely to experience the various forms of discrimination. Surveys were mailed to 1930 practicing physicians in Massachusetts. Participants were asked if they had encountered discrimination, how significant the discrimination was against a specific group, the frequency of personal discrimination, and the type of discrimination. Factor analysis identified four types of discrimination: career advancement, punitive behaviors, practice barriers and hiring barriers. A total of 445 responses were received (a 24% response rate). Sixty-three percent of responding physicians had experienced some form of discrimination. Respondents were women (46%), racial/ethnic minorities (42%) and international medical graduates (IMGs) (40%). In addition, 26% of those classified as white were also IMGs. Over 60% of respondents believed discrimination against IMGs was very or somewhat significant. Almost 27% of males acknowledged that gender bias against females was very or somewhat significant. IMGs were more likely to indicate that discrimination against IMGs was significant in their current organization. Of U.S. medical graduates (USMGs) 44% reported that discrimination against IMGs in their current organization was significant. Nonwhites were more likely to report that discrimination based on race/ethnicity was significant. Nearly 29% of white respondents also believed that such discrimination was very or somewhat significant. Physicians practicing in academic, research, and private practice sectors experience discrimination based on gender, ethnic/racial, and IMG status.

  3. Role of amygdala central nucleus in feature negative discriminations

    Science.gov (United States)

    Holland, Peter C.

    2012-01-01

    Consistent with a popular theory of associative learning, the Pearce-Hall (1980) model, the surprising omission of expected events enhances cue associability (the ease with which a cue may enter into new associations), across a wide variety of behavioral training procedures. Furthermore, previous experiments from this laboratory showed that these enhancements are absent in rats with impaired function of the amygdala central nucleus (CeA). A notable exception to these assertions is found in feature negative (FN) discrimination learning, in which a “target” stimulus is reinforced when it is presented alone but nonreinforced when it is presented in compound with another, “feature” stimulus. According to the Pearce-Hall model, reinforcer omission on compound trials should enhance the associability of the feature relative to control training conditions. However, prior experiments have shown no evidence that CeA lesions affect FN discrimination learning. Here we explored this apparent contradiction by evaluating the hypothesis that the surprising omission of an event confers enhanced associability on a cue only if that cue itself generates the disconfirmed prediction. Thus, in a FN discrimination, the surprising omission of the reinforcer on compound trials would enhance the associability of the target stimulus but not that of the feature. Our data confirmed this hypothesis, and showed this enhancement to depend on intact CeA function, as in other procedures. The results are consistent with modern reformulations of both cue and reward processing theories that assign roles for both individual and aggregate error terms in associative learning. PMID:22889308

  4. Discrimination of foreign language speech contrasts by English monolinguals and French/English bilinguals.

    Science.gov (United States)

    McKelvie-Sebileau, Pippa; Davis, Chris

    2014-05-01

    The primary aim of this study was to determine whether late French/English bilinguals are able to utilize knowledge of bilabial stop contrasts that exist in each of their separate languages to discriminate bilabial stop contrasts from a new language (Thai). Secondary aims were to determine associations between bilabial stop consonant production in the L1 and the L2, between language learning factors and production and discrimination, and to compare English bilinguals' and monolinguals' discrimination. Three Thai bilabial stop consonant pairs differentiated by Voice Onset Time (VOT) (combinations of [b], [p], and [p(h)]) were presented to 28 French-English bilinguals, 25 English-French bilinguals, and 43 English monolinguals in an AX discrimination task. It was hypothesized that L2 experience would facilitate discrimination of contrasts that were phonemic in the L2 but not in the L1 for bilinguals. Only limited support for this hypothesis was found. However, results indicate that high production proficiency bilinguals had higher discrimination of the phonemic L2 contrasts (non-phonemic in L1). Discrimination patterns indicate lasting L1 influence, with similarity between unknown foreign language contrasts and L1 contrasts influencing discrimination rates. Production results show evidence for L2 influence in the L1. Results are discussed in the context of current speech perception models.

  5. Testing for Statistical Discrimination based on Gender

    DEFF Research Database (Denmark)

    Lesner, Rune Vammen

    This paper develops a model which incorporates the two most commonly cited strands of the literature on statistical discrimination, namely screening discrimination and stereotyping. The model is used to provide empirical evidence of statistical discrimination based on gender in the labour market....... It is shown that the implications of both screening discrimination and stereotyping are consistent with observable wage dynamics. In addition, it is found that the gender wage gap decreases in tenure but increases in job transitions and that the fraction of women in high-ranking positions within a firm does...... not affect the level of statistical discrimination by gender....

  6. THE JURIDICAL PROTECTION ON GLOBAL DISCRIMINATION

    Directory of Open Access Journals (Sweden)

    CRISTINA OTOVESCU FRĂSIE

    2012-05-01

    Full Text Available In this study I wished to evidence the main juridical documents referring to discrimination, adopted world wide by the United Nations Organization. Thus, can be identified several types of definitions concerning the discrimination against women, the race discrimination, the torture etc. within the analyzed documents. The democratic countries have laws that punish the discrimination, but, unfortunately, there are discrimination phenomena for example regarding the ethnicity, the gender, the language, the convictions, the age, at the working place, inside the family etc.

  7. Statistical classification methods applied to seismic discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, F.M. [ed.; Anderson, D.N.; Anderson, K.K.; Hagedorn, D.N.; Higbee, K.T.; Miller, N.E.; Redgate, T.; Rohay, A.C.

    1996-06-11

    To verify compliance with a Comprehensive Test Ban Treaty (CTBT), low energy seismic activity must be detected and discriminated. Monitoring small-scale activity will require regional (within {approx}2000 km) monitoring capabilities. This report provides background information on various statistical classification methods and discusses the relevance of each method in the CTBT seismic discrimination setting. Criteria for classification method selection are explained and examples are given to illustrate several key issues. This report describes in more detail the issues and analyses that were initially outlined in a poster presentation at a recent American Geophysical Union (AGU) meeting. Section 2 of this report describes both the CTBT seismic discrimination setting and the general statistical classification approach to this setting. Seismic data examples illustrate the importance of synergistically using multivariate data as well as the difficulties due to missing observations. Classification method selection criteria are presented and discussed in Section 3. These criteria are grouped into the broad classes of simplicity, robustness, applicability, and performance. Section 4 follows with a description of several statistical classification methods: linear discriminant analysis, quadratic discriminant analysis, variably regularized discriminant analysis, flexible discriminant analysis, logistic discriminant analysis, K-th Nearest Neighbor discrimination, kernel discrimination, and classification and regression tree discrimination. The advantages and disadvantages of these methods are summarized in Section 5.

  8. Multipurpose discriminator with accurate time coupling

    International Nuclear Information System (INIS)

    Baldin, B.Yu.; Krumshtejn, Z.V.; Ronzhin, A.I.

    1977-01-01

    The principle diagram of a multipurpose discriminator is described, designed on the basis of a wide-band differential amplifier. The discriminator has three independent channels: the timing channel, the lower level discriminator and the control channel. The timing channel and the lower level discriminator are connected to a coincidence circuit. Three methods of timing are used: a single threshold, a double threshold with timing on the pulse front, and a constant fraction timing. The lower level discriminator is a wide-band amplifier with an adjustable threshold. The investigation of compensation characteristics of the discriminator has shown that the time shift of the discriminator output in the constant fraction timing regime does not exceed +-75 ns for the input signal range of 1:85. The time resolution was found to be 20 ns in the 20% energy range near the photo-peak maximum of 60 Co γ source

  9. Data mining for isotope discrimination in atom probe tomography.

    Science.gov (United States)

    Broderick, Scott R; Bryden, Aaron; Suram, Santosh K; Rajan, Krishna

    2013-09-01

    Ions with similar time-of-flights (TOF) can be discriminated by mapping their kinetic energy. While current generation position-sensitive detectors have been considered insufficient for capturing the isotope kinetic energy, we demonstrate in this paper that statistical learning methodologies can be used to capture the kinetic energy from all of the parameters currently measured by mathematically transforming the signal. This approach works because the kinetic energy is sufficiently described by the descriptors on the potential, the material, and the evaporation process within atom probe tomography (APT). We discriminate the isotopes for Mg and Al by capturing the kinetic energy, and then decompose the TOF spectrum into its isotope components and identify the isotope for each individual atom measured. This work demonstrates the value of advanced data mining methods to help enhance the information resolution of the atom probe. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Quark/gluon jet discrimination: a reproducible analysis using R

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    The power to discriminate between light-quark jets and gluon jets would have a huge impact on many searches for new physics at CERN and beyond. This talk will present a walk-through of the development of a prototype machine learning classifier for differentiating between quark and gluon jets at experiments like those at the Large Hadron Collider at CERN. A new fast feature selection method that combines information theory and graph analytics will be outlined. This method has found new variables that promise significant improvements in discrimination power. The prototype jet tagger is simple, interpretable, parsimonious, and computationally extremely cheap, and therefore might be suitable for use in trigger systems for real-time data processing. Nested stratified k-fold cross validation was used to generate robust estimates of model performance. The data analysis was performed entirely in the R statistical programming language, and is fully reproducible. The entire analysis workflow is data-driven, automated a...

  11. Discriminative Mixed-Membership Models

    Data.gov (United States)

    National Aeronautics and Space Administration — Although mixed-membership models have achieved great success in unsupervised learning, they have not been widely applied to classification problems. In this paper,...

  12. Something worth remembering: visual discrimination in sharks.

    Science.gov (United States)

    Fuss, Theodora; Schluessel, Vera

    2015-03-01

    This study investigated memory retention capabilities of juvenile gray bamboo sharks (Chiloscyllium griseum) using two-alternative forced-choice experiments. The sharks had previously been trained in a range of visual discrimination tasks, such as distinguishing between squares, triangles and lines, and their corresponding optical illusions (i.e., the Kanizsa figures or Müller-Lyer illusions), and in the present study, we tested them for memory retention. Despite the absence of reinforcement, sharks remembered the learned information for a period of up to 50 weeks, after which testing was terminated. In fish, as in other vertebrates, memory windows vary in duration depending on species and task; while it may seem beneficial to retain some information for a long time or even indefinitely, other information may be forgotten more easily to retain flexibility and save energy. The results of this study indicate that sharks are capable of long-term memory within the framework of selected cognitive skills. These could aid sharks in activities such as food retrieval, predator avoidance, mate choice or habitat selection and therefore be worth being remembered for extended periods of time. As in other cognitive tasks, intraspecific differences reflected the behavioral breadth of the species.

  13. Delta 9-tetrahydrocannabinol produced discrimination in pigeons.

    Science.gov (United States)

    Henriksson, B G; Johansson, J O; Järbe, T U

    1975-01-01

    In an operant situation pigeons learned to peck one response key 90 min after an injection of 0.25mg/kg delta9-tetrahydrocannabinol (delta9-THC) and another key when trained nondrugged. When tested with doses of delta9-THC lwer than the training dose the birds disciminated 0.20 mg/kg of the drug from the nondrugged state but not 0.15 mg/kg or lower doses. The animals were able to discriminate the drug state from the nondrugged 180 min but not 360 min after the injection At a shorter interval (45 min) both drug and nondrug responding appeared. Cannabinol and cannabidiol (4.0 - 8.0 mg/kg) did not elicit any drug responses, nor did pentobarbital, ditran or amphetamine. Tests with LSD resulted in both drug and nondrug responding. When administering noncannabinoid drugs in combination with delta9-THC 0.15 mg/kg the birds responded at the key associated with the drug state, suggesting interactional effects.

  14. Robust Discriminant Regression for Feature Extraction.

    Science.gov (United States)

    Lai, Zhihui; Mo, Dongmei; Wong, Wai Keung; Xu, Yong; Miao, Duoqian; Zhang, David

    2017-10-09

    Ridge regression (RR) and its extended versions are widely used as an effective feature extraction method in pattern recognition. However, the RR-based methods are sensitive to the variations of data and can learn only limited number of projections for feature extraction and recognition. To address these problems, we propose a new method called robust discriminant regression (RDR) for feature extraction. In order to enhance the robustness, the L₂,₁-norm is used as the basic metric in the proposed RDR. The designed robust objective function in regression form can be solved by an iterative algorithm containing an eigenfunction, through which the optimal orthogonal projections of RDR can be obtained by eigen decomposition. The convergence analysis and computational complexity are presented. In addition, we also explore the intrinsic connections and differences between the RDR and some previous methods. Experiments on some well-known databases show that RDR is superior to the classical and very recent proposed methods reported in the literature, no matter the L₂-norm or the L₂,₁-norm-based regression methods. The code of this paper can be downloaded from http://www.scholat.com/laizhihui.

  15. Social identity change in response to discrimination.

    Science.gov (United States)

    Perozzo, Cristina; de la Sablonnière, Roxane; Auger, Emilie; Caron-Diotte, Mathieu

    2016-09-01

    This study investigated the conditions under which discrimination can lead to social identity changes among members of a minority group. Both positive and negative relations between perceptions of discrimination and social identity have previously been reported. To explain the conflicting results and understand the complex reality of members of stigmatized groups, we argue that group-based emotions (e.g., group-based dissatisfaction) and ambiguity of discrimination cues (i.e., overt vs. ambiguous) need to be considered. We hypothesized that perceptions of discrimination would play a moderating role between group-based dissatisfaction and social identity change in a context of ambiguous, but not of overt, discrimination. The sample was comprised of 151 Arab Muslims living in the province of Quebec. Participants read fictitious newspaper articles portraying either overt (n = 76) or ambiguous (n = 75) discrimination towards in-group members. Results revealed that for participants in the overt discrimination condition, only group-based dissatisfaction was positively associated with social identity change. In contrast, for the participants in the ambiguous discrimination condition, those who perceived little discrimination and felt low group-based dissatisfaction reported a decrease in social identity. However, those who perceived low group discrimination and felt high group-based dissatisfaction reported a positive social identity change. © 2016 The British Psychological Society.

  16. Perceived age discrimination in older adults

    Science.gov (United States)

    Rippon, Isla; Kneale, Dylan; de Oliveira, Cesar; Demakakos, Panayotes; Steptoe, Andrew

    2014-01-01

    Objectives: to examine perceived age discrimination in a large representative sample of older adults in England. Methods: this cross-sectional study of over 7,500 individuals used data from the fifth wave of the English Longitudinal Study of Ageing (ELSA), a longitudinal cohort study of men and women aged 52 years and older in England. Wave 5 asked respondents about the frequency of five everyday discriminatory situations. Participants who attributed any experiences of discrimination to their age were treated as cases of perceived age discrimination. Multivariable logistic regression analysis was used to estimate the odds ratios of experiencing perceived age discrimination in relation to selected sociodemographic factors. Results: approximately a third (33.3%) of all respondents experienced age discrimination, rising to 36.8% in those aged 65 and over. Perceived age discrimination was associated with older age, higher education, lower levels of household wealth and being retired or not in employment. The correlates of age discrimination across the five discriminatory situations were similar. Conclusion: understanding age discrimination is vital if we are to develop appropriate policies and to target future interventions effectively. These findings highlight the scale of the challenge of age discrimination for older adults in England and illustrate that those groups are particularly vulnerable to this form of discrimination. PMID:24077751

  17. Discrimination and subjective well-being: protective influences of membership in a discriminated category.

    Science.gov (United States)

    Hnilica, Karel

    2011-03-01

    Research reveals that discrimination has harmful effects on health and quality of life. Among the most frequent types of discrimination pertains gender and age discrimination. Research results show that discriminatory behaviours based on gender afflict predominantly women; age discrimination afflicts mainly older adults. At the same time, it has been found that members of these traditionally discriminated categories often use strategies that mitigate the effects of discrimination. Discrimination will have detrimental effects on subjective well-being. But its effects will be most harmful for persons who are not members of the traditionally discriminated categories. These hypotheses were tested on data from three waves of the European Social Survey that the Czech Republic also participated in. Data were analyzed in a series of multilevel random coefficients regression analyses with respondents nested within states and states nested within years of study. Both perceived gender discrimination and perceived age discrimination have negative effects on subjective well-being. However, gender discrimination had more harmful effects on the subjective well-being of men than women and age discrimination had the most harmful effects on the subjective well-being of people in their middle ages, not the elderly ones. Discrimination does not need to have most harmful effects on the quality of life of members of the categories that are discriminated against most often.

  18. Universal programmable devices for unambiguous discrimination

    International Nuclear Information System (INIS)

    Zhang Chi; Ying Mingsheng; Qiao, Bo

    2006-01-01

    We discuss the problem of designing unambiguous programmable discriminators for any n unknown quantum states in an m-dimensional Hilbert space. The discriminator is a fixed measurement that has two kinds of input registers: the program registers and the data register. The quantum state in the data register is what users want to identify, which is confirmed to be among the n states in program registers. The task of the discriminator is to tell the users which state stored in the program registers is equivalent to that in the data register. First, we give a necessary and sufficient condition for judging an unambiguous programmable discriminator. Then, if m=n, we present an optimal unambiguous programmable discriminator for them, in the sense of maximizing the worst-case probability of success. Finally, we propose a universal unambiguous programmable discriminator for arbitrary n quantum states

  19. Universal programmable devices for unambiguous discrimination

    Science.gov (United States)

    Zhang, Chi; Ying, Mingsheng; Qiao, Bo

    2006-10-01

    We discuss the problem of designing unambiguous programmable discriminators for any n unknown quantum states in an m -dimensional Hilbert space. The discriminator is a fixed measurement that has two kinds of input registers: the program registers and the data register. The quantum state in the data register is what users want to identify, which is confirmed to be among the n states in program registers. The task of the discriminator is to tell the users which state stored in the program registers is equivalent to that in the data register. First, we give a necessary and sufficient condition for judging an unambiguous programmable discriminator. Then, if m=n , we present an optimal unambiguous programmable discriminator for them, in the sense of maximizing the worst-case probability of success. Finally, we propose a universal unambiguous programmable discriminator for arbitrary n quantum states.

  20. Fast differential pulse discriminator-counter

    International Nuclear Information System (INIS)

    Shelevoj, K.D.

    1985-01-01

    The flowsheet of a differential pulse discriminator counter is described; the result of discrimination here is independent from the shape of the input pulse. Rate of the analysis of input pulses with minimum amplitude up to 0.3 mV coming out from the photomultiplier makes up 220 MHz. The flowsheet of the discriminator used in the system of photon counting for atmosphere probing is presented