Does Mother Tongue Interfere in Second Language Learning?

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Elif Nur Denizer

2017-01-01

Full Text Available Mother tongue largely refers to not only the language one learns from one’s mother but also the speaker’s dominant and home language. It’s also called native language. This study was conducted to find whether mother tongue interferences in second-language learning, and if so; whether it affects the learners’ performance in four language skills, and also in which skill(s it has the biggest effect. Data collection tool included a questionnaire by which participants were asked to rate the questions and tick-circle or write in the correct blank. The questionnaire was based on both quantitative and qualitative approaches with the help of 4-point Likert-scale questions and one open-ended question at the last part. The participants of the study were 20 volunteer students (15 females and 5 males in Uludag University on whom the questionnaire was randomly applied.  They ranged in age from 18 to 40 and the mean age was 23. Their mother tongue was Turkish, and they knew English as a foreign language. The questionnaire shows that mother tongue interferes with second language learning in some way. In English language, the most challenging part was Grammar, while the most difficult and influenced skills was Speaking. In addition, participants had difficulty with speaking without any preparation. When it comes to having difficulty, participants had difficulty with determiners, English tenses and articles. The results indicated the interference of mother tongue in almost all aspects.

Testing complex animal cognition: Concept learning, proactive interference, and list memory.

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Wright, Anthony A

2018-01-01

This article describes an approach for assessing and comparing complex cognition in rhesus monkeys and pigeons by training them in a sequence of synergistic tasks, each yielding a whole function for enhanced comparisons. These species were trained in similar same/different tasks with expanding training sets (8, 16, 32, 64, 128 … 1024 pictures) followed by novel-stimulus transfer eventually resulting in full abstract-concept learning. Concept-learning functions revealed better rhesus transfer throughout and full concept learning at the 128 set, versus pigeons at the 256 set. They were then tested in delayed same/different tasks for proactive interference by inserting occasional tests within trial-unique sessions where the test stimulus matched a previous sample stimulus (1, 2, 4, 8, 16 trials prior). Proactive-interference functions revealed time-based interference for pigeons (1, 10 s delays), but event-based interference for rhesus (no effect of 1, 10, 20 s delays). They were then tested in list-memory tasks by expanding the sample to four samples in trial-unique sessions (minimizing proactive interference). The four-item, list-memory functions revealed strong recency memory at short delays, gradually changing to strong primacy memory at long delays over 30 s for rhesus, and 10 s for pigeons. Other species comparisons and future directions are discussed. © 2018 Society for the Experimental Analysis of Behavior.

Comparing cognition by integrating concept learning, proactive interference, and list memory.

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Wright, Anthony A; Kelly, Debbie M; Katz, Jeffrey S

2018-06-01

This article describes an approach for training a variety of species to learn the abstract concept of same/different, which in turn forms the basis for testing proactive interference and list memory. The stimulus set for concept-learning training was progressively doubled from 8, 16, 32, 64, 128 . . . to 1,024 different pictures with novel-stimulus transfer following learning. All species fully learned the same/different abstract concept: capuchin and rhesus monkeys learned more readily than pigeons; nutcrackers and magpies were at least equivalent to monkeys and transferred somewhat better following initial training sets. A similar task using the 1,024-picture set plus delays was used to test proactive interference on occasional trials. Pigeons revealed greater interference with 10-s than with 1-s delays, whereas delay time had no effect on rhesus monkeys, suggesting that the monkeys' interference was event based. This same single-item same/different task was expanded to a 4-item list memory task to test animal list memory. Humans were tested similarly with lists of kaleidoscope pictures. Delays between the list and test were manipulated, resulting in strong initial recency effects (i.e., strong 4th-item memory) at short delays and changing to a strong primacy effect (i.e., strong 1st-item memory) at long delays (pigeons 0-s to 10-s delays; monkeys 0-s to 30-s delays; humans 0-s to 100-s delays). Results and findings are discussed in terms of these species' cognition and memory comparisons, evolutionary implications, and future directions for testing other species in these synergistically related tasks.

Contextual Interference Effects in Learning Three Badminton Serves.

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Goode, Sinah; Magill, Richard A.

1986-01-01

This study was made to validate results obtained in laboratory research. Thirty female students learned three badminton serves in either a low, mixed, or high interference practice schedule and were given a retention and transfer test. Results are discussed. (Author/MT)

Predicting memory performance under conditions of proactive interference: immediate and delayed judgments of learning.

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Wahlheim, Christopher N

2011-07-01

Four experiments examined the monitoring accuracy of immediate and delayed judgments of learning (JOLs) under conditions of proactive interference (PI). PI was produced using paired-associate learning tasks that conformed to variations of classic A-B, A-D paradigms. Results revealed that the relative monitoring accuracy of interference items was better for delayed than for immediate JOLs. However, delayed JOLs were overconfident for interference items, but not for items devoid of interference. Intrusions retrieved prior to delayed JOLs produced inflated predictions of performance. These results show that delayed JOLs enhance monitoring accuracy in PI situations, except when intrusions are mistaken for target responses.

Does Mother Tongue Interfere in Second Language Learning?

OpenAIRE

Denizer, Elif Nur

2017-01-01

Mother tongue largely refers to not only the language one learns from one’s mother but also the speaker’s dominant and home language. It’s also called native language. This study was conducted to find whether mother tongue interferences in second-language learning, and if so; whether it affects the learners’ performance in four language skills, and also in which skill(s) it has the biggest effect. Data collection tool included a questionnaire by which participants were asked to rate the quest...

Interference effects in learning similar sequences of discrete movements

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Koedijker, J.M.; Oudejans, R.R.D.; Beek, P.J.

2010-01-01

Three experiments were conducted to examine proactive and retroactive interference effects in learning two similar sequences of discrete movements. In each experiment, the participants in the experimental group practiced two movement sequences on consecutive days (1 on each day, order

Aging increases the susceptibility to motor memory interference and reduces off-line gains in motor skill learning

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Roig, Marc; Ritterband-Rosenbaum, Anina; Jensen, Jesper Lundbye

2014-01-01

Declines in the ability to learn motor skills in older adults are commonly attributed to deficits in the encoding of sensorimotor information during motor practice. We investigated whether aging also impairs motor memory consolidation by assessing the susceptibility to memory interference and off...... greater susceptibility to memory interference and no off-line gains in motor skill learning. Performing B produced memory interference and reduced off-line gains only in the older group. However, older adults also showed deficits in memory consolidation independent of the interfering effects of B. Age......-related declines in motor skill learning are not produced exclusively by deficits in the encoding of sensorimotor information during practice. Aging also increases the susceptibility to memory interference and reduces off-line gains in motor skill learning after practice....

Spatial Context Learning Survives Interference from Working Memory Load

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Vickery, Timothy J.; Sussman, Rachel S.; Jiang, Yuhong V.

2010-01-01

The human visual system is constantly confronted with an overwhelming amount of information, only a subset of which can be processed in complete detail. Attention and implicit learning are two important mechanisms that optimize vision. This study addressed the relationship between these two mechanisms. Specifically we asked, Is implicit learning…

Serial-order learning impairment and hypersensitivity-to-interference in dyscalculia.

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De Visscher, Alice; Szmalec, Arnaud; Van Der Linden, Lize; Noël, Marie-Pascale

2015-11-01

In the context of heterogeneity, the different profiles of dyscalculia are still hypothetical. This study aims to link features of mathematical difficulties to certain potential etiologies. First, we wanted to test the hypothesis of a serial-order learning deficit in adults with dyscalculia. For this purpose we used a Hebb repetition learning task. Second, we wanted to explore a recent hypothesis according to which hypersensitivity-to-interference hampers the storage of arithmetic facts and leads to a particular profile of dyscalculia. We therefore used interfering and non-interfering repeated sequences in the Hebb paradigm. A final test was used to assess the memory trace of the non-interfering sequence and the capacity to manipulate it. In line with our predictions, we observed that people with dyscalculia who show good conceptual knowledge in mathematics but impaired arithmetic fluency suffer from increased sensitivity-to-interference compared to controls. Secondly, people with dyscalculia who show a deficit in a global mathematical test suffer from a serial-order learning deficit characterized by a slow learning and a quick degradation of the memory trace of the repeated sequence. A serial-order learning impairment could be one of the explanations for a basic numerical deficit, since it is necessary for the number-word sequence acquisition. Among the different profiles of dyscalculia, this study provides new evidence and refinement for two particular profiles. Copyright © 2015 Elsevier B.V. All rights reserved.

The role of outcome inhibition in interference between outcomes: a contingency-learning analogue of retrieval-induced forgetting.

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Vadillo, Miguel A; Orgaz, Cristina; Luque, David; Cobos, Pedro L; López, Francisco J; Matute, Helena

2013-05-01

Current associative theories of contingency learning assume that inhibitory learning plays a part in the interference between outcomes. However, it is unclear whether this inhibitory learning results in the inhibition of the outcome representation or whether it simply counteracts previous excitatory learning so that the outcome representation is neither activated nor inhibited. Additionally, these models tend to conceptualize inhibition as a relatively transient and cue-dependent state. However, research on retrieval-induced forgetting suggests that the inhibition of representations is a real process that can be relatively independent of the retrieval cue used to access the inhibited information. Consistent with this alternative view, we found that interference between outcomes reduces the retrievability of the target outcome even when the outcome is associated with a novel (non-inhibitory) cue. This result has important theoretical implications for associative models of interference and shows that the empirical facts and theories developed in studies of retrieval-induced forgetting might be relevant in contingency learning and vice versa. © 2012 The British Psychological Society.

Dorsolateral Striatum Engagement Interferes with Early Discrimination Learning

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Hadley C. Bergstrom

2018-05-01

Full Text Available Summary: In current models, learning the relationship between environmental stimuli and the outcomes of actions involves both stimulus-driven and goal-directed systems, mediated in part by the DLS and DMS, respectively. However, though these models emphasize the importance of the DLS in governing actions after extensive experience has accumulated, there is growing evidence of DLS engagement from the onset of training. Here, we used in vivo photosilencing to reveal that DLS recruitment interferes with early touchscreen discrimination learning. We also show that the direct output pathway of the DLS is preferentially recruited and causally involved in early learning and find that silencing the normal contribution of the DLS produces plasticity-related alterations in a PL-DMS circuit. These data provide further evidence suggesting that the DLS is recruited in the construction of stimulus-elicited actions that ultimately automate behavior and liberate cognitive resources for other demands, but with a cost to performance at the outset of learning. : What is the contribution of the DLS in early discrimination learning? Bergstrom et al. show using in vivo optogenetics, fluorescence in situ hybridization, and brain-wide activity mapping that silencing the DLS facilitates early discrimination learning, drives activity in a parallel PL-DMS circuit, and preferentially recruits the DLS “direct” output pathway. Keywords: striatum, reward, goal-directed, habit, optogenetics, plasticity, cognition, Arc

Deep learning predictions of survival based on MRI in amyotrophic lateral sclerosis.

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van der Burgh, Hannelore K; Schmidt, Ruben; Westeneng, Henk-Jan; de Reus, Marcel A; van den Berg, Leonard H; van den Heuvel, Martijn P

2017-01-01

Amyotrophic lateral sclerosis (ALS) is a progressive neuromuscular disease, with large variation in survival between patients. Currently, it remains rather difficult to predict survival based on clinical parameters alone. Here, we set out to use clinical characteristics in combination with MRI data to predict survival of ALS patients using deep learning, a machine learning technique highly effective in a broad range of big-data analyses. A group of 135 ALS patients was included from whom high-resolution diffusion-weighted and T1-weighted images were acquired at the first visit to the outpatient clinic. Next, each of the patients was monitored carefully and survival time to death was recorded. Patients were labeled as short, medium or long survivors, based on their recorded time to death as measured from the time of disease onset. In the deep learning procedure, the total group of 135 patients was split into a training set for deep learning (n = 83 patients), a validation set (n = 20) and an independent evaluation set (n = 32) to evaluate the performance of the obtained deep learning networks. Deep learning based on clinical characteristics predicted survival category correctly in 68.8% of the cases. Deep learning based on MRI predicted 62.5% correctly using structural connectivity and 62.5% using brain morphology data. Notably, when we combined the three sources of information, deep learning prediction accuracy increased to 84.4%. Taken together, our findings show the added value of MRI with respect to predicting survival in ALS, demonstrating the advantage of deep learning in disease prognostication.

Interference and deception detection technology of satellite navigation based on deep learning

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Chen, Weiyi; Deng, Pingke; Qu, Yi; Zhang, Xiaoguang; Li, Yaping

2017-10-01

Satellite navigation system plays an important role in people's daily life and war. The strategic position of satellite navigation system is prominent, so it is very important to ensure that the satellite navigation system is not disturbed or destroyed. It is a critical means to detect the jamming signal to avoid the accident in a navigation system. At present, the detection technology of jamming signal in satellite navigation system is not intelligent , mainly relying on artificial decision and experience. For this issue, the paper proposes a method based on deep learning to monitor the interference source in a satellite navigation. By training the interference signal data, and extracting the features of the interference signal, the detection sys tem model is constructed. The simulation results show that, the detection accuracy of our detection system can reach nearly 70%. The method in our paper provides a new idea for the research on intelligent detection of interference and deception signal in a satellite navigation system.

Machine learning models in breast cancer survival prediction.

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Montazeri, Mitra; Montazeri, Mohadeseh; Montazeri, Mahdieh; Beigzadeh, Amin

2016-01-01

Breast cancer is one of the most common cancers with a high mortality rate among women. With the early diagnosis of breast cancer survival will increase from 56% to more than 86%. Therefore, an accurate and reliable system is necessary for the early diagnosis of this cancer. The proposed model is the combination of rules and different machine learning techniques. Machine learning models can help physicians to reduce the number of false decisions. They try to exploit patterns and relationships among a large number of cases and predict the outcome of a disease using historical cases stored in datasets. The objective of this study is to propose a rule-based classification method with machine learning techniques for the prediction of different types of Breast cancer survival. We use a dataset with eight attributes that include the records of 900 patients in which 876 patients (97.3%) and 24 (2.7%) patients were females and males respectively. Naive Bayes (NB), Trees Random Forest (TRF), 1-Nearest Neighbor (1NN), AdaBoost (AD), Support Vector Machine (SVM), RBF Network (RBFN), and Multilayer Perceptron (MLP) machine learning techniques with 10-cross fold technique were used with the proposed model for the prediction of breast cancer survival. The performance of machine learning techniques were evaluated with accuracy, precision, sensitivity, specificity, and area under ROC curve. Out of 900 patients, 803 patients and 97 patients were alive and dead, respectively. In this study, Trees Random Forest (TRF) technique showed better results in comparison to other techniques (NB, 1NN, AD, SVM and RBFN, MLP). The accuracy, sensitivity and the area under ROC curve of TRF are 96%, 96%, 93%, respectively. However, 1NN machine learning technique provided poor performance (accuracy 91%, sensitivity 91% and area under ROC curve 78%). This study demonstrates that Trees Random Forest model (TRF) which is a rule-based classification model was the best model with the highest level of

A new semi-supervised learning model combined with Cox and SP-AFT models in cancer survival analysis.

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Chai, Hua; Li, Zi-Na; Meng, De-Yu; Xia, Liang-Yong; Liang, Yong

2017-10-12

Gene selection is an attractive and important task in cancer survival analysis. Most existing supervised learning methods can only use the labeled biological data, while the censored data (weakly labeled data) far more than the labeled data are ignored in model building. Trying to utilize such information in the censored data, a semi-supervised learning framework (Cox-AFT model) combined with Cox proportional hazard (Cox) and accelerated failure time (AFT) model was used in cancer research, which has better performance than the single Cox or AFT model. This method, however, is easily affected by noise. To alleviate this problem, in this paper we combine the Cox-AFT model with self-paced learning (SPL) method to more effectively employ the information in the censored data in a self-learning way. SPL is a kind of reliable and stable learning mechanism, which is recently proposed for simulating the human learning process to help the AFT model automatically identify and include samples of high confidence into training, minimizing interference from high noise. Utilizing the SPL method produces two direct advantages: (1) The utilization of censored data is further promoted; (2) the noise delivered to the model is greatly decreased. The experimental results demonstrate the effectiveness of the proposed model compared to the traditional Cox-AFT model.

Frequent video game players resist perceptual interference.

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Aaron V Berard

Full Text Available Playing certain types of video games for a long time can improve a wide range of mental processes, from visual acuity to cognitive control. Frequent gamers have also displayed generalized improvements in perceptual learning. In the Texture Discrimination Task (TDT, a widely used perceptual learning paradigm, participants report the orientation of a target embedded in a field of lines and demonstrate robust over-night improvement. However, changing the orientation of the background lines midway through TDT training interferes with overnight improvements in overall performance on TDT. Interestingly, prior research has suggested that this effect will not occur if a one-hour break is allowed in between the changes. These results have suggested that after training is over, it may take some time for learning to become stabilized and resilient against interference. Here, we tested whether frequent gamers have faster stabilization of perceptual learning compared to non-gamers and examined the effect of daily video game playing on interference of training of TDT with one background orientation on perceptual learning of TDT with a different background orientation. As a result, we found that non-gamers showed overnight performance improvement only on one background orientation, replicating previous results with the interference in TDT. In contrast, frequent gamers demonstrated overnight improvements in performance with both background orientations, suggesting that they are better able to overcome interference in perceptual learning. This resistance to interference suggests that video game playing not only enhances the amplitude and speed of perceptual learning but also leads to faster and/or more robust stabilization of perceptual learning.

Frequent video game players resist perceptual interference.

Science.gov (United States)

Berard, Aaron V; Cain, Matthew S; Watanabe, Takeo; Sasaki, Yuka

2015-01-01

Playing certain types of video games for a long time can improve a wide range of mental processes, from visual acuity to cognitive control. Frequent gamers have also displayed generalized improvements in perceptual learning. In the Texture Discrimination Task (TDT), a widely used perceptual learning paradigm, participants report the orientation of a target embedded in a field of lines and demonstrate robust over-night improvement. However, changing the orientation of the background lines midway through TDT training interferes with overnight improvements in overall performance on TDT. Interestingly, prior research has suggested that this effect will not occur if a one-hour break is allowed in between the changes. These results have suggested that after training is over, it may take some time for learning to become stabilized and resilient against interference. Here, we tested whether frequent gamers have faster stabilization of perceptual learning compared to non-gamers and examined the effect of daily video game playing on interference of training of TDT with one background orientation on perceptual learning of TDT with a different background orientation. As a result, we found that non-gamers showed overnight performance improvement only on one background orientation, replicating previous results with the interference in TDT. In contrast, frequent gamers demonstrated overnight improvements in performance with both background orientations, suggesting that they are better able to overcome interference in perceptual learning. This resistance to interference suggests that video game playing not only enhances the amplitude and speed of perceptual learning but also leads to faster and/or more robust stabilization of perceptual learning.

Learning to learn: step one for survival in the new paradigm.

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Muller-Smith, P

1997-08-01

New challenges require new approaches and many of the suggested solutions are in conflict with how we were taught in our formative years. Team work in high school and college was mostly found in sports-related activities. Collaboration in a classroom was not encouraged and could be viewed as cheating. We did not learn to share knowledge in a group nor to group problem solving, yet we are told that those are the very skills we need to have to survive in today's workplace. The first step to success is to look at how we were taught to learn and make the shift to learning in a different manner.

Knowledge Reuse Method to Improve the Learning of Interference-Preventive Allocation Policies in Multi-Car Elevators

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Valdivielso Chian, Alex; Miyamoto, Toshiyuki

In this letter, we introduce a knowledge reuse method to improve the performance of a learning algorithm developed to prevent interference in multi-car elevators. This method enables the algorithm to use its previously acquired experience in new learning processes. The simulation results confirm the improvement achieved in the algorithm's performance.

A model of human motor sequence learning explains facilitation and interference effects based on spike-timing dependent plasticity.

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Quan Wang

2017-08-01

Full Text Available The ability to learn sequential behaviors is a fundamental property of our brains. Yet a long stream of studies including recent experiments investigating motor sequence learning in adult human subjects have produced a number of puzzling and seemingly contradictory results. In particular, when subjects have to learn multiple action sequences, learning is sometimes impaired by proactive and retroactive interference effects. In other situations, however, learning is accelerated as reflected in facilitation and transfer effects. At present it is unclear what the underlying neural mechanism are that give rise to these diverse findings. Here we show that a recently developed recurrent neural network model readily reproduces this diverse set of findings. The self-organizing recurrent neural network (SORN model is a network of recurrently connected threshold units that combines a simplified form of spike-timing dependent plasticity (STDP with homeostatic plasticity mechanisms ensuring network stability, namely intrinsic plasticity (IP and synaptic normalization (SN. When trained on sequence learning tasks modeled after recent experiments we find that it reproduces the full range of interference, facilitation, and transfer effects. We show how these effects are rooted in the network's changing internal representation of the different sequences across learning and how they depend on an interaction of training schedule and task similarity. Furthermore, since learning in the model is based on fundamental neuronal plasticity mechanisms, the model reveals how these plasticity mechanisms are ultimately responsible for the network's sequence learning abilities. In particular, we find that all three plasticity mechanisms are essential for the network to learn effective internal models of the different training sequences. This ability to form effective internal models is also the basis for the observed interference and facilitation effects. This suggests that

The Role of Work-home Interference and Workplace Learning in the Energy-depletion Process

NARCIS (Netherlands)

Ruysseveldt, Joris; Proost, Karin; Verboon, Peter

2011-01-01

In this study, we tested a work stress model which incorporates both an energydepletion and a workplace learning process. In the energy-depletion process, workhome interference was assumed to mediate the relationship between job demands (workload, emotional demands) and psychological fatigue. In

Long-term interference at the semantic level: Evidence from blocked-cyclic picture matching.

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Wei, Tao; Schnur, Tatiana T

2016-01-01

Processing semantically related stimuli creates interference across various domains of cognition, including language and memory. In this study, we identify the locus and mechanism of interference when retrieving meanings associated with words and pictures. Subjects matched a probe stimulus (e.g., cat) to its associated target picture (e.g., yarn) from an array of unrelated pictures. Across trials, probes were either semantically related or unrelated. To test the locus of interference, we presented probes as either words or pictures. If semantic interference occurs at the stage common to both tasks, that is, access to semantic representations, then interference should occur in both probe presentation modalities. Results showed clear semantic interference effects independent of presentation modality and lexical frequency, confirming a semantic locus of interference in comprehension. To test the mechanism of interference, we repeated trials across 4 presentation cycles and manipulated the number of unrelated intervening trials (zero vs. two). We found that semantic interference was additive across cycles and survived 2 intervening trials, demonstrating interference to be long-lasting as opposed to short-lived. However, interference was smaller with zero versus 2 intervening trials, which we interpret to suggest that short-lived facilitation counteracted the long-lived interference. We propose that retrieving meanings associated with words/pictures from the same semantic category yields both interference due to long-lasting changes in connection strength between semantic representations (i.e., incremental learning) and facilitation caused by short-lived residual activation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

The Nature and Diagnosis of Interference Phenomena.

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Denison, Norman

1966-01-01

The recognition of the systematic nature of the interference of the mother tongue when learning a second language is among the most significant advances in linguistics for the teaching and learning of foreign languages. The work of Weinreich showed that interference between language systems--the absorption of loan words, calques, and phonological,…

The external-internal loop of interference: two types of attention and their influence on the learning abilities of mice.

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Sauce, Bruno; Wass, Christopher; Smith, Andrew; Kwan, Stephanie; Matzel, Louis D

2014-12-01

Attention is a component of the working memory system, and is responsible for protecting task-relevant information from interference. Cognitive performance (particularly outside of the laboratory) is often plagued by interference, and the source of this interference, either external or internal, might influence the expression of individual differences in attentional ability. By definition, external attention (also described as "selective attention") protects working memory against sensorial distractors of all kinds, while internal attention (also called "inhibition") protects working memory against emotional impulses, irrelevant information from memory, and automatically-generated responses. At present, it is unclear if these two types of attention are expressed independently in non-human animals, and how they might differentially impact performance on other cognitive processes, such as learning. By using a diverse battery of four attention tests (with varying levels of internal and external sources of interference), here we aimed both to explore this issue, and to obtain a robust and general (less task-specific) measure of attention in mice. Exploratory factor analyses revealed two factors (external and internal attention) that in total, accounted for 73% of the variance in attentional performance. Confirmatory factor analyses found an excellent fit with the data of the model of attention that assumed an external and internal distinction (with a resulting correlation of 0.43). In contrast, a model of attention that assumed one source of variance (i.e., "general attention") exhibited a poor fit with the data. Regarding the relationship between attention and learning, higher resistance against external sources of interference promoted better new learning, but tended to impair performance when cognitive flexibility was required, such as during the reversal of a previously instantiated response. The present results suggest that there can be (at least) two types of

Developmental Change in Proactive Interference.

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Kail, Robert

2002-01-01

Two studies examined age-related change in proactive interference from previously learned material. The meta-analysis of 26 studies indicated that proactive interference decreased with age. The cross-sectional study found that third through sixth graders' and college students' recall was accurate on Trial 1, but became less so over Trials 2…

The Survival Processing Effect with Intentional Learning of Ad Hoc Categories

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Anastasiya Savchenko

2014-04-01

Full Text Available Previous studies have shown that memory is adapted to remember information when it is processed in a survival context. This study investigates how procedural changes in Marinho (2012 study might have led to her failure to replicate the survival mnemonic advantage. In two between-subjects design experiments, participants were instructed to learn words from ad hoc categories and to rate their relevance to a survival or a control scenario. No survival advantage was obtained in either experiment. The Adjusted Ratio of Clustering (ARC scores revealed that including the category labels made the participants rely more on the category structure of the list. Various procedural aspects of the conducted experiments are discussed as possible reasons underlying the absence of the survival effect.

Reduced Interference from Memory Testing: A Postretrieval Monitoring Account

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Pierce, Benton H.; Gallo, David A.; McCain, Jason L.

2017-01-01

Initial learning can interfere with subsequent learning (proactive interference [PI]), but recent work indicates initial testing can reduce PI. Here, we tested 2 alternative hypotheses of this effect: Does testing reduce PI by constraining retrieval to the target list, or by facilitating a postretrieval monitoring process? Participants first…

Hierarchical Meta-Learning in Time Series Forecasting for Improved Interference-Less Machine Learning

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David Afolabi

2017-11-01

Full Text Available The importance of an interference-less machine learning scheme in time series prediction is crucial, as an oversight can have a negative cumulative effect, especially when predicting many steps ahead of the currently available data. The on-going research on noise elimination in time series forecasting has led to a successful approach of decomposing the data sequence into component trends to identify noise-inducing information. The empirical mode decomposition method separates the time series/signal into a set of intrinsic mode functions ranging from high to low frequencies, which can be summed up to reconstruct the original data. The usual assumption that random noises are only contained in the high-frequency component has been shown not to be the case, as observed in our previous findings. The results from that experiment reveal that noise can be present in a low frequency component, and this motivates the newly-proposed algorithm. Additionally, to prevent the erosion of periodic trends and patterns within the series, we perform the learning of local and global trends separately in a hierarchical manner which succeeds in detecting and eliminating short/long term noise. The algorithm is tested on four datasets from financial market data and physical science data. The simulation results are compared with the conventional and state-of-the-art approaches for time series machine learning, such as the non-linear autoregressive neural network and the long short-term memory recurrent neural network, respectively. Statistically significant performance gains are recorded when the meta-learning algorithm for noise reduction is used in combination with these artificial neural networks. For time series data which cannot be decomposed into meaningful trends, applying the moving average method to create meta-information for guiding the learning process is still better than the traditional approach. Therefore, this new approach is applicable to the forecasting

Characterizing Interference in Radio Astronomy Observations through Active and Unsupervised Learning

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Doran, G.

2013-01-01

In the process of observing signals from astronomical sources, radio astronomers must mitigate the effects of manmade radio sources such as cell phones, satellites, aircraft, and observatory equipment. Radio frequency interference (RFI) often occurs as short bursts (active learning approach in which an astronomer labels events that are most confusing to a classifier, minimizing the human effort required for classification. We also explore the use of unsupervised clustering techniques, which automatically group events into classes without user input. We apply these techniques to data from the Parkes Multibeam Pulsar Survey to characterize several million detected RFI events from over a thousand hours of observation.

Assessing segmentation processes by click detection: online measure of statistical learning, or simple interference?

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Franco, Ana; Gaillard, Vinciane; Cleeremans, Axel; Destrebecqz, Arnaud

2015-12-01

Statistical learning can be used to extract the words from continuous speech. Gómez, Bion, and Mehler (Language and Cognitive Processes, 26, 212-223, 2011) proposed an online measure of statistical learning: They superimposed auditory clicks on a continuous artificial speech stream made up of a random succession of trisyllabic nonwords. Participants were instructed to detect these clicks, which could be located either within or between words. The results showed that, over the length of exposure, reaction times (RTs) increased more for within-word than for between-word clicks. This result has been accounted for by means of statistical learning of the between-word boundaries. However, even though statistical learning occurs without an intention to learn, it nevertheless requires attentional resources. Therefore, this process could be affected by a concurrent task such as click detection. In the present study, we evaluated the extent to which the click detection task indeed reflects successful statistical learning. Our results suggest that the emergence of RT differences between within- and between-word click detection is neither systematic nor related to the successful segmentation of the artificial language. Therefore, instead of being an online measure of learning, the click detection task seems to interfere with the extraction of statistical regularities.

Motivational Interference in School-Leisure Conflict and Learning Outcomes: The Differential Effects of Two Value Conceptions

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Hofer, Manfred; Kuhnle, Claudia; Kilian, Britta; Marta, Elena; Fries, Stefan

2011-01-01

It was hypothesized that students' value orientations are connected to their experience of motivational interference in a conflict between a school- and a leisure-related activity as well as to school marks as indicators of learning outcomes. In a self-report study with Italian adolescents (N = 433; M = 14.5 years) using a school-leisure conflict…

Memory Reactivation Enables Long-Term Prevention of Interference.

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Herszage, Jasmine; Censor, Nitzan

2017-05-22

The ability of the human brain to successively learn or perform two competing tasks constitutes a major challenge in daily function. Indeed, exposing the brain to two different competing memories within a short temporal offset can induce interference, resulting in deteriorated performance in at least one of the learned memories [1-4]. Although previous studies have investigated online interference and its effects on performance [5-13], whether the human brain can enable long-term prevention of future interference is unknown. To address this question, we utilized the memory reactivation-reconsolidation framework [2, 12] stemming from studies at the synaptic level [14-17], according to which reactivation of a memory enables its update. In a set of experiments, using the motor sequence learning task [18] we report that a unique pairing of reactivating the original memory (right hand) in synchrony with novel memory trials (left hand) prevented future interference between the two memories. Strikingly, these effects were long-term and observed a month following reactivation. Further experiments showed that preventing future interference was not due to practice per se, but rather specifically depended on a limited time window induced by reactivation of the original memory. These results suggest a mechanism according to which memory reactivation enables long-term prevention of interference, possibly by creating an updated memory trace integrating original and novel memories during the reconsolidation time window. The opportunity to induce a long-term preventive effect on memories may enable the utilization of strategies optimizing normal human learning, as well as recovery following neurological insults. Copyright © 2017 Elsevier Ltd. All rights reserved.

Learning Survival Models with On-Line Simulation Activities in the Actuarial Science Degree

Directory of Open Access Journals (Sweden)

Antonio Fernandez-Morales

2011-03-01

Full Text Available The aim of this paper is to describe an on-line survival laboratory designed to enhance teaching and learning in the Statistics courses of the Actuarial Science Degree of the Uni-versity of Málaga. The objective of the on-line survival lab is to help students through a guided program of simulation activities with the understanding of the most important statistical concepts of the stochastic modeling of human survival, from an Actuarial point of view. The graphical interactive simulator is implemented as Java applets for the web version, and as a Javascript animation for a lite iPhone/iPod touch version. Finally, the results of a survey carried out at the end of the course are discussed to have a preliminary assessment of the students’ satisfaction with the resources, and their perception about the usefulness for their learning process.

Intrusions in story recall: when over-learned information interferes with episodic memory recall. Evidence from Alzheimer's disease.

Science.gov (United States)

De Anna, Francesca; Attali, Eve; Freynet, Laurence; Foubert, Lucie; Laurent, Aurore; Dubois, Bruno; Dalla Barba, Gianfranco

2008-03-01

Patients with Alzheimer's disease (AD) suffer from distortions of memory. Among such distortions, intrusions in memory tests are frequently observed. In this study we describe the performance of a group of mild AD patients and a group of normal controls on the recall of three different types of stories: a previously unknown story, a well-known fairy-tale (Cinderella), and a modified well-known fairy-tale (Little Red Riding Hood is not eaten by the wolf). The aim of our study was to test the hypothesis that in patients who tend to produce intrusions, over-learned information interferes with episodic recall, i.e., the retrieval of specific, unique past episodes. AD patients produced significantly more intrusions in the recall of the modified fairy-tale compared to the recall of the two other stories. Intrusions in the recall of the modified fairy-tale always consisted of elements of the original version of the story. We suggest that in AD patients intrusions may be traced back to the interference of strongly represented, over-learned information in episodic memory recall.

Impact of censoring on learning Bayesian networks in survival modelling.

Science.gov (United States)

Stajduhar, Ivan; Dalbelo-Basić, Bojana; Bogunović, Nikola

2009-11-01

Bayesian networks are commonly used for presenting uncertainty and covariate interactions in an easily interpretable way. Because of their efficient inference and ability to represent causal relationships, they are an excellent choice for medical decision support systems in diagnosis, treatment, and prognosis. Although good procedures for learning Bayesian networks from data have been defined, their performance in learning from censored survival data has not been widely studied. In this paper, we explore how to use these procedures to learn about possible interactions between prognostic factors and their influence on the variate of interest. We study how censoring affects the probability of learning correct Bayesian network structures. Additionally, we analyse the potential usefulness of the learnt models for predicting the time-independent probability of an event of interest. We analysed the influence of censoring with a simulation on synthetic data sampled from randomly generated Bayesian networks. We used two well-known methods for learning Bayesian networks from data: a constraint-based method and a score-based method. We compared the performance of each method under different levels of censoring to those of the naive Bayes classifier and the proportional hazards model. We did additional experiments on several datasets from real-world medical domains. The machine-learning methods treated censored cases in the data as event-free. We report and compare results for several commonly used model evaluation metrics. On average, the proportional hazards method outperformed other methods in most censoring setups. As part of the simulation study, we also analysed structural similarities of the learnt networks. Heavy censoring, as opposed to no censoring, produces up to a 5% surplus and up to 10% missing total arcs. It also produces up to 50% missing arcs that should originally be connected to the variate of interest. Presented methods for learning Bayesian networks from

Reducing Retroactive Interference through the Use of Different Encoding Techniques: An Exploration of Pre-Test/Post-Test Analyses

Science.gov (United States)

Cumming, John M.; De Miranda, Michael A.

2012-01-01

Retroactive interference (RI) in list learning occurs when the learning of a second list of words interferes with the recall of the first learned list. Having the lists be thematically different can reduce retroactive interference within list learning; however, this study demonstrates how RI can be reduced when the lists contain similar words.…

Learning evaluation of interference and diffraction of light in physics laboratory

Directory of Open Access Journals (Sweden)

Silvia Bravo

2016-08-01

Full Text Available This paper presents the results of an investigation referred to the learning of interference and diffraction of light in the context of a physic laboratory, through the application of a didactic proposal with students from an undergraduate course in physics. The design of the experimental activities has taken into account the difficulties reported by educational research, as well as the contribution of the Vergnaud conceptual fields theory, Ausubel meaningful learning theory and Vigotsky sociolinguistics theory. The research was focused in the study of students cognitive development during the implementation of the didactic proposal and the assessment of it through the skills development. A methodological qualitative approach was used, in an interpretative perspective, with a research-action design, where the researcher acts as a teacher while he collects the data. Researcher's field notes have been used in a complementarily, audio recordings of group interactions, video recordings of students’ teamwork, group reports about the individual activities and assessments. The results obtained from the analysis of the content of the registers and the interpretation from the theory of conceptual fields show an evolution in the students’ schemes. Their initials schemes, which were focused on ray optics, evolve to schemes focused on the wave model. The results obtained from the group reports and from the individual assessment show that all the students have managed to develop most skills raised as learning objectives in the didactic proposal.

Quantum Interference and Entanglement Induced by Multiple Scattering of Light

DEFF Research Database (Denmark)

Ott, Johan Raunkjær; Mortensen, Asger; Lodahl, Peter

2010-01-01

We report on the effects of quantum interference induced by the transmission of an arbitrary number of optical quantum states through a multiple-scattering medium. We identify the role of quantum interference on the photon correlations and the degree of continuous variable entanglement between two...... output modes. It is shown that quantum interference survives averaging over all ensembles of disorder and manifests itself as increased photon correlations due to photon antibunching. Furthermore, the existence of continuous variable entanglement correlations in a volume speckle pattern is predicted. Our...

Quantum Interference and Selectivity through Biological Ion Channels.

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Salari, Vahid; Naeij, Hamidreza; Shafiee, Afshin

2017-01-30

The mechanism of selectivity in ion channels is still an open question in biology for more than half a century. Here, we suggest that quantum interference can be a solution to explain the selectivity mechanism in ion channels since interference happens between similar ions through the same size of ion channels. In this paper, we simulate two neighboring ion channels on a cell membrane with the famous double-slit experiment in physics to investigate whether there is any possibility of matter-wave interference of ions via movement through ion channels. Our obtained decoherence timescales indicate that the quantum states of ions can only survive for short times, i.e. ≈100 picoseconds in each channel and ≈17-53 picoseconds outside the channels, giving the result that the quantum interference of ions seems unlikely due to environmental decoherence. However, we discuss our results and raise few points, which increase the possibility of interference.

Radiation enhancement effect of RNA interference for HIF-1α on the transplant tumor

International Nuclear Information System (INIS)

Ren Ruimei; Sun Xindong; Zhao Hanxi; Yan Qingxia; Huang Guangwu

2008-01-01

Objective: To determine and explore the radiation enhancement of RNA interference for HIF-1α on the transplant tumor using polycationic polyethylenimine (PEI), as a new kind of gene vector. Methods: SPCA-1 nude mouse model was used. 160 nude mice bearing SPCA-1 were randomly divided into 4 treated groups and 1 control groups, each group had 32 mice. The expression of HIF-1α was studied by immunohistochemical method after RNA interference for HIF-1α. The differences of the volume, weight, survival time of the transplant tumor were studied among the simple radiation group, the simple RNA interference for HIF- 1α group and the combination of radiation and RNA interference for HIF-1α. Results: The expression of HIF-1α was decreased after RNA interference for HIF-1α. RNA interference for HIF-1α combined with radiation decreased the volume, weight of the transplant tumor, and prolonged its survival time period significantly than other methods. Conclusions: RNA interference targeting HIF-1α might enhance the radiosensitivity of the transplant tumor using PEI as a new kind of gene vector in vitro. (authors)

Does recall after sleep-dependent memory consolidation reinstate sensitivity to retroactive interference?

Science.gov (United States)

Deliens, Gaétane; Schmitz, Rémy; Caudron, Isaline; Mary, Alison; Leproult, Rachel; Peigneux, Philippe

2013-01-01

Previous studies have shown that newly encoded memories are more resistant to retroactive interference when participants are allowed to sleep after learning the original material, suggesting a sleep-related strengthening of memories. In the present study, we investigated delayed, long-term effects of sleep vs. sleep deprivation (SD) on the first post-training night on memory consolidation and resistance to interference. On day 1, participants learned a list of unrelated word pairs (AB), either in the morning or in the evening, then spent the post-training night in a sleep or sleep deprivation condition, in a within-subject paradigm. On day 4, at the same time of day, they learned a novel list of word pairs (AC) in which 50% of the word pairs stemmed with the same word than in the AB list, resulting in retroactive interference. Participants had then to recall items from the AB list upon presentation of the "A" stem. Recall was marginally improved in the evening, as compared to the morning learning group. Most importantly, retroactive interference effects were found in the sleep evening group only, contrary to the hypothesis that sleep exerts a protective role against intrusion by novel but similar learning. We tentatively suggest that these results can be explained in the framework of the memory reconsolidation theory, stating that exposure to similar information sets back consolidated items in a labile form again sensitive to retroactive interference. In this context, sleep might not protect against interference but would promote an update of existing episodic memories while preventing saturation of the memory network due to the accumulation of dual traces.

Does recall after sleep-dependent memory consolidation reinstate sensitivity to retroactive interference?

Directory of Open Access Journals (Sweden)

Gaétane Deliens

Full Text Available Previous studies have shown that newly encoded memories are more resistant to retroactive interference when participants are allowed to sleep after learning the original material, suggesting a sleep-related strengthening of memories. In the present study, we investigated delayed, long-term effects of sleep vs. sleep deprivation (SD on the first post-training night on memory consolidation and resistance to interference. On day 1, participants learned a list of unrelated word pairs (AB, either in the morning or in the evening, then spent the post-training night in a sleep or sleep deprivation condition, in a within-subject paradigm. On day 4, at the same time of day, they learned a novel list of word pairs (AC in which 50% of the word pairs stemmed with the same word than in the AB list, resulting in retroactive interference. Participants had then to recall items from the AB list upon presentation of the "A" stem. Recall was marginally improved in the evening, as compared to the morning learning group. Most importantly, retroactive interference effects were found in the sleep evening group only, contrary to the hypothesis that sleep exerts a protective role against intrusion by novel but similar learning. We tentatively suggest that these results can be explained in the framework of the memory reconsolidation theory, stating that exposure to similar information sets back consolidated items in a labile form again sensitive to retroactive interference. In this context, sleep might not protect against interference but would promote an update of existing episodic memories while preventing saturation of the memory network due to the accumulation of dual traces.

46 CFR 199.130 - Stowage of survival craft.

Science.gov (United States)

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Stowage of survival craft. 199.130 Section 199.130... craft. (a) General. Each survival craft must be stowed— (1) As close to the accommodation and service spaces as possible; (2) So that neither the survival craft nor its stowage arrangements will interfere...

Methods for reducing interference in the Complementary Learning Systems model: oscillating inhibition and autonomous memory rehearsal.

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Norman, Kenneth A; Newman, Ehren L; Perotte, Adler J

2005-11-01

The stability-plasticity problem (i.e. how the brain incorporates new information into its model of the world, while at the same time preserving existing knowledge) has been at the forefront of computational memory research for several decades. In this paper, we critically evaluate how well the Complementary Learning Systems theory of hippocampo-cortical interactions addresses the stability-plasticity problem. We identify two major challenges for the model: Finding a learning algorithm for cortex and hippocampus that enacts selective strengthening of weak memories, and selective punishment of competing memories; and preventing catastrophic forgetting in the case of non-stationary environments (i.e. when items are temporarily removed from the training set). We then discuss potential solutions to these problems: First, we describe a recently developed learning algorithm that leverages neural oscillations to find weak parts of memories (so they can be strengthened) and strong competitors (so they can be punished), and we show how this algorithm outperforms other learning algorithms (CPCA Hebbian learning and Leabra at memorizing overlapping patterns. Second, we describe how autonomous re-activation of memories (separately in cortex and hippocampus) during REM sleep, coupled with the oscillating learning algorithm, can reduce the rate of forgetting of input patterns that are no longer present in the environment. We then present a simple demonstration of how this process can prevent catastrophic interference in an AB-AC learning paradigm.

Learning Structure of Sensory Inputs with Synaptic Plasticity Leads to Interference

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Joseph eChrol-Cannon

2015-08-01

Full Text Available Synaptic plasticity is often explored as a form of unsupervised adaptationin cortical microcircuits to learn the structure of complex sensoryinputs and thereby improve performance of classification and prediction. The question of whether the specific structure of the input patterns is encoded in the structure of neural networks has been largely neglected. Existing studies that have analyzed input-specific structural adaptation have used simplified, synthetic inputs in contrast to complex and noisy patterns found in real-world sensory data.In this work, input-specific structural changes are analyzed forthree empirically derived models of plasticity applied to three temporal sensory classification tasks that include complex, real-world visual and auditory data. Two forms of spike-timing dependent plasticity (STDP and the Bienenstock-Cooper-Munro (BCM plasticity rule are used to adapt the recurrent network structure during the training process before performance is tested on the pattern recognition tasks.It is shown that synaptic adaptation is highly sensitive to specific classes of input pattern. However, plasticity does not improve the performance on sensory pattern recognition tasks, partly due to synaptic interference between consecutively presented input samples. The changes in synaptic strength produced by one stimulus are reversed by thepresentation of another, thus largely preventing input-specific synaptic changes from being retained in the structure of the network.To solve the problem of interference, we suggest that models of plasticitybe extended to restrict neural activity and synaptic modification to a subset of the neural circuit, which is increasingly found to be the casein experimental neuroscience.

Sixty-eight years of experimental occlusal interference studies: what have we learned?

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Clark, G T; Tsukiyama, Y; Baba, K; Watanabe, T

1999-12-01

Understanding is needed regarding the effect that occlusal interferences have on the teeth, periodontium, and especially on jaw function. This article summarizes research in which experimental occlusal interferences have been placed on the teeth of animals and human volunteers. Data from 18 human and 10 animals studies were reviewed. Experimental occlusal interferences were grouped into those that alter intercuspal position and those contacting on lateral jaw movement only. The outcome of these interferences were analyzed according to their local pulpal-periodontal, jaw function, or bruxism effects. Experimental occlusal interferences in maximum intercuspation had a deleterious effect on periodontal and pulpal tissues of the affected tooth; sometimes this produces a disruption of smooth jaw function and occasionally jaw muscle pain and clicking. Experimental occlusal interferences that contact only in a lateral jaw movement are infrequently harmful to jaw function. Furthermore, no reliable evidence demonstrates that occlusal interferences can cause nocturnal bruxism, or stop it. Transient local tooth pain, loosening of the tooth, a slight change in postural muscle tension levels, chewing stroke patterns, and sometimes a clicking joint can be induced by an experimental occlusal interference. Because such findings are present in relatively asymptomatic patients, these data do not prove that occlusal interferences are causally related to a chronic jaw muscle pain or temporomandibular joint dysfunction problems.

Microbial interference with hatch and survival of European eel larvae

DEFF Research Database (Denmark)

Sørensen, Sune Riis; Lauesen; Tomkiewicz, Jonna

Recent research has significantly improved our knowledge and capabilities in the field of in vitro production of yolk sac larvae from European eel (Anguilla anguilla). Female broodstock European eels are matured by weekly administration of pituitary extract and male eels with hCG (human chorionic...... larviculture should not only focus on optimizing physical incubation conditions, but certainly also on the control over microbial interference....

Cancer survival analysis using semi-supervised learning method based on Cox and AFT models with L1/2 regularization.

Science.gov (United States)

Liang, Yong; Chai, Hua; Liu, Xiao-Ying; Xu, Zong-Ben; Zhang, Hai; Leung, Kwong-Sak

2016-03-01

One of the most important objectives of the clinical cancer research is to diagnose cancer more accurately based on the patients' gene expression profiles. Both Cox proportional hazards model (Cox) and accelerated failure time model (AFT) have been widely adopted to the high risk and low risk classification or survival time prediction for the patients' clinical treatment. Nevertheless, two main dilemmas limit the accuracy of these prediction methods. One is that the small sample size and censored data remain a bottleneck for training robust and accurate Cox classification model. In addition to that, similar phenotype tumours and prognoses are actually completely different diseases at the genotype and molecular level. Thus, the utility of the AFT model for the survival time prediction is limited when such biological differences of the diseases have not been previously identified. To try to overcome these two main dilemmas, we proposed a novel semi-supervised learning method based on the Cox and AFT models to accurately predict the treatment risk and the survival time of the patients. Moreover, we adopted the efficient L1/2 regularization approach in the semi-supervised learning method to select the relevant genes, which are significantly associated with the disease. The results of the simulation experiments show that the semi-supervised learning model can significant improve the predictive performance of Cox and AFT models in survival analysis. The proposed procedures have been successfully applied to four real microarray gene expression and artificial evaluation datasets. The advantages of our proposed semi-supervised learning method include: 1) significantly increase the available training samples from censored data; 2) high capability for identifying the survival risk classes of patient in Cox model; 3) high predictive accuracy for patients' survival time in AFT model; 4) strong capability of the relevant biomarker selection. Consequently, our proposed semi

Cross-limb Interference during motor learning

DEFF Research Database (Denmark)

Lauber, Benedikt; Jensen, Jesper Lundbye; Keller, Martin

2013-01-01

It is well known that following skill learning, improvements in motor performance may transfer to the untrained contralateral limb. It is also well known that retention of a newly learned task A can be degraded when learning a competing task B that takes place directly after learning A. Here we...

Role of Business Management into the Success and Survival of Small Businesses: The Case of Star Learning Centre in Botswana

OpenAIRE

Fridah Muriungi Mwobobia

2012-01-01

The study aimed to establish the aspects of management, which have led to the survival, and success of the small-scale businesses in Botswana- a case of Star Learning Centre. The questions explored were 1) What is the role of management in the survival or success of Star Learning Centre? 2) What management styles, systems and practices are appropriate for Star Learning Centre and other small scale businesses in the Botswana? 3) What work culture is appropriate for business success? 4) What fa...

A Novel Application of Machine Learning Methods to Model Microcontroller Upset Due to Intentional Electromagnetic Interference

Science.gov (United States)

Bilalic, Rusmir

A novel application of support vector machines (SVMs), artificial neural networks (ANNs), and Gaussian processes (GPs) for machine learning (GPML) to model microcontroller unit (MCU) upset due to intentional electromagnetic interference (IEMI) is presented. In this approach, an MCU performs a counting operation (0-7) while electromagnetic interference in the form of a radio frequency (RF) pulse is direct-injected into the MCU clock line. Injection times with respect to the clock signal are the clock low, clock rising edge, clock high, and the clock falling edge periods in the clock window during which the MCU is performing initialization and executing the counting procedure. The intent is to cause disruption in the counting operation and model the probability of effect (PoE) using machine learning tools. Five experiments were executed as part of this research, each of which contained a set of 38,300 training points and 38,300 test points, for a total of 383,000 total points with the following experiment variables: injection times with respect to the clock signal, injected RF power, injected RF pulse width, and injected RF frequency. For the 191,500 training points, the average training error was 12.47%, while for the 191,500 test points the average test error was 14.85%, meaning that on average, the machine was able to predict MCU upset with an 85.15% accuracy. Leaving out the results for the worst-performing model (SVM with a linear kernel), the test prediction accuracy for the remaining machines is almost 89%. All three machine learning methods (ANNs, SVMs, and GPML) showed excellent and consistent results in their ability to model and predict the PoE on an MCU due to IEMI. The GP approach performed best during training with a 7.43% average training error, while the ANN technique was most accurate during the test with a 10.80% error.

The survive and thrive program: encouraging coaching, mentoring, and peer learning among new local health officials.

Science.gov (United States)

Henry, Vonna; Sarpy, Sue Ann; Green, Rachel; Kaplan, Seth; Bonzon, Ramon

2010-01-01

There is a need for programs tailored to train the approximately 300 new local health officials (LHOs) who emerge each year with the knowledge and skills needed to build, maintain, and enhance public health capacity and infrastructure. The Survive and Thrive program incorporates a curriculum that is designed to address the challenges faced by a new LHO. The Survive and Thrive program seeks to address these issues by leveraging the expertise of the current generation of local public health leadership by incorporating experienced LHOs as coaches. Coaching, mentoring, and peer assistance by seasoned LHOs is critical to these new learning opportunities. This article highlights aspects of the coaching component of Survive and Thrive program. Actual examples of its relevance to the professional growth and development of new LHOs and the coaches themselves are presented. The article also describes the novel approach of including coaches in evaluating program effectiveness. The Survive and Thrive program's coaching component can serve as a template for other public health leadership programs and related workforce development initiatives as well as a model to help facilitate lifelong learning of LHOs.

Four types of interference competition and their impacts on the ecology and evolution of size-structured populations and communities

DEFF Research Database (Denmark)

Zhang, Lai; Andersen, Ken Haste; Dieckmann, Ulf

2015-01-01

We investigate how four types of interference competition - which alternatively affect foraging, metabolism, survival, and reproduction - impact the ecology and evolution of size-structured populations. Even though all four types of interference competition reduce population biomass, interference...

Prediction of lung cancer patient survival via supervised machine learning classification techniques.

Science.gov (United States)

Lynch, Chip M; Abdollahi, Behnaz; Fuqua, Joshua D; de Carlo, Alexandra R; Bartholomai, James A; Balgemann, Rayeanne N; van Berkel, Victor H; Frieboes, Hermann B

2017-12-01

Outcomes for cancer patients have been previously estimated by applying various machine learning techniques to large datasets such as the Surveillance, Epidemiology, and End Results (SEER) program database. In particular for lung cancer, it is not well understood which types of techniques would yield more predictive information, and which data attributes should be used in order to determine this information. In this study, a number of supervised learning techniques is applied to the SEER database to classify lung cancer patients in terms of survival, including linear regression, Decision Trees, Gradient Boosting Machines (GBM), Support Vector Machines (SVM), and a custom ensemble. Key data attributes in applying these methods include tumor grade, tumor size, gender, age, stage, and number of primaries, with the goal to enable comparison of predictive power between the various methods The prediction is treated like a continuous target, rather than a classification into categories, as a first step towards improving survival prediction. The results show that the predicted values agree with actual values for low to moderate survival times, which constitute the majority of the data. The best performing technique was the custom ensemble with a Root Mean Square Error (RMSE) value of 15.05. The most influential model within the custom ensemble was GBM, while Decision Trees may be inapplicable as it had too few discrete outputs. The results further show that among the five individual models generated, the most accurate was GBM with an RMSE value of 15.32. Although SVM underperformed with an RMSE value of 15.82, statistical analysis singles the SVM as the only model that generated a distinctive output. The results of the models are consistent with a classical Cox proportional hazards model used as a reference technique. We conclude that application of these supervised learning techniques to lung cancer data in the SEER database may be of use to estimate patient survival time

The sleeping brain's influence on verbal memory: boosting resistance to interference.

Directory of Open Access Journals (Sweden)

Jeffrey M Ellenbogen

Full Text Available Memories evolve. After learning something new, the brain initiates a complex set of post-learning processing that facilitates recall (i.e., consolidation. Evidence points to sleep as one of the determinants of that change. But whenever a behavioral study of episodic memory shows a benefit of sleep, critics assert that sleep only leads to a temporary shelter from the damaging effects of interference that would otherwise accrue during wakefulness. To evaluate the potentially active role of sleep for verbal memory, we compared memory recall after sleep, with and without interference before testing. We demonstrated that recall performance for verbal memory was greater after sleep than after wakefulness. And when using interference testing, that difference was even more pronounced. By introducing interference after sleep, this study confirms an experimental paradigm that demonstrates the active role of sleep in consolidating memory, and unmasks the large magnitude of that benefit.

Consolidation of an olfactory memory trace in the olfactory bulb is required for learning-induced survival of adult-born neurons and long-term memory.

Directory of Open Access Journals (Sweden)

Florence Kermen

Full Text Available BACKGROUND: It has recently been proposed that adult-born neurons in the olfactory bulb, whose survival is modulated by learning, support long-term olfactory memory. However, the mechanism used to select which adult-born neurons following learning will participate in the long-term retention of olfactory information is unknown. We addressed this question by investigating the effect of bulbar consolidation of olfactory learning on memory and neurogenesis. METHODOLOGY/PRINCIPAL FINDINGS: Initially, we used a behavioral ecological approach using adult mice to assess the impact of consolidation on neurogenesis. Using learning paradigms in which consolidation time was varied, we showed that a spaced (across days, but not a massed (within day, learning paradigm increased survival of adult-born neurons and allowed long-term retention of the task. Subsequently, we used a pharmacological approach to block consolidation in the olfactory bulb, consisting in intrabulbar infusion of the protein synthesis inhibitor anisomycin, and found impaired learning and no increase in neurogenesis, while basic olfactory processing and the basal rate of adult-born neuron survival remained unaffected. Taken together these data indicate that survival of adult-born neurons during learning depends on consolidation processes taking place in the olfactory bulb. CONCLUSION/SIGNIFICANCE: We can thus propose a model in which consolidation processes in the olfactory bulb determine both survival of adult-born neurons and long-term olfactory memory. The finding that adult-born neuron survival during olfactory learning is governed by consolidation in the olfactory bulb strongly argues in favor of a role for bulbar adult-born neurons in supporting olfactory memory.

Consolidation of an olfactory memory trace in the olfactory bulb is required for learning-induced survival of adult-born neurons and long-term memory.

Science.gov (United States)

Kermen, Florence; Sultan, Sébastien; Sacquet, Joëlle; Mandairon, Nathalie; Didier, Anne

2010-08-13

It has recently been proposed that adult-born neurons in the olfactory bulb, whose survival is modulated by learning, support long-term olfactory memory. However, the mechanism used to select which adult-born neurons following learning will participate in the long-term retention of olfactory information is unknown. We addressed this question by investigating the effect of bulbar consolidation of olfactory learning on memory and neurogenesis. Initially, we used a behavioral ecological approach using adult mice to assess the impact of consolidation on neurogenesis. Using learning paradigms in which consolidation time was varied, we showed that a spaced (across days), but not a massed (within day), learning paradigm increased survival of adult-born neurons and allowed long-term retention of the task. Subsequently, we used a pharmacological approach to block consolidation in the olfactory bulb, consisting in intrabulbar infusion of the protein synthesis inhibitor anisomycin, and found impaired learning and no increase in neurogenesis, while basic olfactory processing and the basal rate of adult-born neuron survival remained unaffected. Taken together these data indicate that survival of adult-born neurons during learning depends on consolidation processes taking place in the olfactory bulb. We can thus propose a model in which consolidation processes in the olfactory bulb determine both survival of adult-born neurons and long-term olfactory memory. The finding that adult-born neuron survival during olfactory learning is governed by consolidation in the olfactory bulb strongly argues in favor of a role for bulbar adult-born neurons in supporting olfactory memory.

Developing and Validating a Survival Prediction Model for NSCLC Patients Through Distributed Learning Across 3 Countries.

Science.gov (United States)

Jochems, Arthur; Deist, Timo M; El Naqa, Issam; Kessler, Marc; Mayo, Chuck; Reeves, Jackson; Jolly, Shruti; Matuszak, Martha; Ten Haken, Randall; van Soest, Johan; Oberije, Cary; Faivre-Finn, Corinne; Price, Gareth; de Ruysscher, Dirk; Lambin, Philippe; Dekker, Andre

2017-10-01

Tools for survival prediction for non-small cell lung cancer (NSCLC) patients treated with chemoradiation or radiation therapy are of limited quality. In this work, we developed a predictive model of survival at 2 years. The model is based on a large volume of historical patient data and serves as a proof of concept to demonstrate the distributed learning approach. Clinical data from 698 lung cancer patients, treated with curative intent with chemoradiation or radiation therapy alone, were collected and stored at 2 different cancer institutes (559 patients at Maastro clinic (Netherlands) and 139 at Michigan university [United States]). The model was further validated on 196 patients originating from The Christie (United Kingdon). A Bayesian network model was adapted for distributed learning (the animation can be viewed at https://www.youtube.com/watch?v=ZDJFOxpwqEA). Two-year posttreatment survival was chosen as the endpoint. The Maastro clinic cohort data are publicly available at https://www.cancerdata.org/publication/developing-and-validating-survival-prediction-model-nsclc-patients-through-distributed, and the developed models can be found at www.predictcancer.org. Variables included in the final model were T and N category, age, performance status, and total tumor dose. The model has an area under the curve (AUC) of 0.66 on the external validation set and an AUC of 0.62 on a 5-fold cross validation. A model based on the T and N category performed with an AUC of 0.47 on the validation set, significantly worse than our model (PLearning the model in a centralized or distributed fashion yields a minor difference on the probabilities of the conditional probability tables (0.6%); the discriminative performance of the models on the validation set is similar (P=.26). Distributed learning from federated databases allows learning of predictive models on data originating from multiple institutions while avoiding many of the data-sharing barriers. We believe that

Interference-free acquisition of overlapping sequences in explicit spatial memory.

Science.gov (United States)

Eggert, Thomas; Drever, Johannes; Straube, Andreas

2014-04-01

Some types of human sequential memory, e.g. the acquisition of a new composition by a trained musician, seem to be very efficient in extending the length of a memorized sequence and in flexible reuse of known subsequences in a newly acquired sequential context. This implies that interference between known and newly acquired subsequences can be avoided even when learning a sequence which is a partial mutation of a known sequence. It is known that established motor sequences do not have such flexibility. Using learning of deferred imitation, the current study investigates the flexibility of explicit spatial memory by quantifying the interferences between successively acquired, partially overlapping sequences. After learning a spatial sequence on day 1, this sequence was progressively modified on day 2. On day 3, a retention test was performed with both the initial and the modified sequence. The results show that subjects performed very well on day 1 and day 2. No spatial interference between changed and unchanged targets was observed during the stepwise progressive modification of the reproduced sequence. Surprisingly, subjects performed well on both sequences on day 3. Comparison with a control experiment without intermediate mutation training showed that the initial training on day 1 did not proactively interfere with the retention of the modified sequence on day 3. Vice versa, the mutation training on day 2 did not interfere retroactively with the retention of the original sequence as tested on day 3. The results underline the flexibility in acquiring explicit spatial memory. Copyright © 2014 Elsevier B.V. All rights reserved.

Increased Stroop interference with better second-language reading skill.

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Braet, Wouter; Noppe, Nele; Wagemans, Johan; Op de Beeck, Hans

2011-03-01

Skilled readers demonstrate remarkable efficiency in processing written words, unlike beginning readers for whom reading occurs more serially and places higher demands on visual attention. In the present study, we used the Stroop paradigm to investigate the relationship between reading skill and automaticity, in individuals learning a second language with a different orthographic system. Prior studies using this paradigm have presented a mixed picture, finding a positive, a negative, or no relationship between the size of Stroop interference and reading skills. Our results show that Stroop interference in the second language was positively related to reading skill (when controlled for interference in the first language). Furthermore, interference was positively related to objective but not subjective indices of the amount of exposure to the second language. We suggest that the lack of consistency in the results of earlier studies may be due, at least in part, to these studies looking at Stroop interference in isolation, rather than comparing interference between languages.

LANGUAGE AND CULTURE INTERFERENCE IN PLURILINGUAL EDUCATION

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Hackett-Jones, A.V.

2016-09-01

Full Text Available The article deals with interlingual phenomena that occur in the process of multiple language acquisition in a learning environment. The notions of language interference and transfer put forward by the theories of bilingualism, give useful insights when applied to the modern day educational trends. Language and culture interference is an important aspect to be considered with regard to teaching of plurilingual learners, whose communicative competence is formed on the basis of several linguistic and cultural systems that interact with each other and exert mutual influence.

Neural Tuning Functions Underlie Both Generalization and Interference.

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Ian S Howard

Full Text Available In sports, the role of backswing is considered critical for generating a good shot, even though it plays no direct role in hitting the ball. We recently demonstrated the scientific basis of this phenomenon by showing that immediate past movement affects the learning and recall of motor memories. This effect occurred regardless of whether the past contextual movement was performed actively, passively, or shown visually. In force field studies, it has been shown that motor memories generalize locally and that the level of compensation decays as a function of movement angle away from the trained movement. Here we examine if the contextual effect of past movement exhibits similar patterns of generalization and whether it can explain behavior seen in interference studies. Using a single force-field learning task, the directional tuning curves of both the prior contextual movement and the subsequent force field adaptive movements were measured. The adaptation movement direction showed strong directional tuning, decaying to zero by 90° relative to the training direction. The contextual movement direction exhibited a similar directional tuning, although the effect was always above 60%. We then investigated the directional tuning of the passive contextual movement using interference tasks, where the contextual movements that uniquely specified the force field direction were separated by ±15° or ±45°. Both groups showed a pronounced tuning effect, which could be well explained by the directional tuning functions for single force fields. Our results show that contextual effect of past movement influences predictive force compensation, even when adaptation does not require contextual information. However, when such past movement contextual information is crucial to the task, such as in an interference study, it plays a strong role in motor memory learning and recall. This work demonstrates that similar tuning responses underlie both generalization of

Autobiographical thinking interferes with episodic memory consolidation.

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Michael Craig

Full Text Available New episodic memories are retained better if learning is followed by a few minutes of wakeful rest than by the encoding of novel external information. Novel encoding is said to interfere with the consolidation of recently acquired episodic memories. Here we report four experiments in which we examined whether autobiographical thinking, i.e. an 'internal' memory activity, also interferes with episodic memory consolidation. Participants were presented with three wordlists consisting of common nouns; one list was followed by wakeful rest, one by novel picture encoding and one by autobiographical retrieval/future imagination, cued by concrete sounds. Both novel encoding and autobiographical retrieval/future imagination lowered wordlist retention significantly. Follow-up experiments demonstrated that the interference by our cued autobiographical retrieval/future imagination delay condition could not be accounted for by the sound cues alone or by executive retrieval processes. Moreover, our results demonstrated evidence of a temporal gradient of interference across experiments. Thus, we propose that rich autobiographical retrieval/future imagination hampers the consolidation of recently acquired episodic memories and that such interference is particularly likely in the presence of external concrete cues.

Interference from previous distraction disrupts older adults' memory.

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Biss, Renée K; Campbell, Karen L; Hasher, Lynn

2013-07-01

Previously relevant information can disrupt the ability of older adults to remember new information. Here, the researchers examined whether prior irrelevant information, or distraction, can also interfere with older adults' memory for new information. Younger and older adults first completed a 1-back task on pictures that were superimposed with distracting words. After a delay, participants learned picture-word paired associates and memory was tested using picture-cued recall. In 1 condition (high interference), some pairs included pictures from the 1-back task now paired with new words. In a low-interference condition, the transfer list used all new items. Older adults had substantially lower cued-recall performance in the high- compared with the low-interference condition. In contrast, younger adults' performance did not vary across conditions. These findings suggest that even never-relevant information from the past can disrupt older adults' memory for new associations.

Preserved cumulative semantic interference despite amnesia

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Gary Michael Oppenheim

2015-05-01

As predicted by Oppenheim et al’s (2010 implicit incremental learning account, WRP’s BCN RTs demonstrated strong (and significant repetition priming and semantic blocking effects (Figure 1. Similar to typical results from neurally intact undergraduates, WRP took longer to name pictures presented in semantically homogeneous blocks than in heterogeneous blocks, an effect that increased with each cycle. This result challenges accounts that ascribe cumulative semantic interference in this task to explicit memory mechanisms, instead suggesting that the effect has the sort of implicit learning bases that are typically spared in hippocampal amnesia.

Barriers to repeated assessment of verbal learning and memory: a comparison of international shopping list task and rey auditory verbal learning test on build-up of proactive interference.

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Rahimi-Golkhandan, S; Maruff, P; Darby, D; Wilson, P

2012-11-01

Proactive interference (PI) that remains unidentified can confound the assessment of verbal learning, particularly when its effects vary from one population to another. The International Shopping List Task (ISLT) is a new measure that provides multiple forms that can be equated for linguistic factors across cultural groups. The aim of this study was to examine the build-up of PI on two measures of verbal learning-a traditional test of list learning (Rey Auditory Verbal Learning Test, RAVLT) and the ISLT. The sample consisted of 61 healthy adults aged 18-40. Each test had three parallel forms, each recalled three times. Results showed that repeated administration of the ISLT did not result in significant PI effects, unlike the RAVLT. Although these PI effects, observed during short retest intervals, may not be as robust under normal clinical administrations of the tests, the results suggest that the choice of the verbal learning test should be guided by the knowledge of PI effects and the susceptibility of particular patient groups to this effect.

Auditory and motor imagery modulate learning in music performance.

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Brown, Rachel M; Palmer, Caroline

2013-01-01

Skilled performers such as athletes or musicians can improve their performance by imagining the actions or sensory outcomes associated with their skill. Performers vary widely in their auditory and motor imagery abilities, and these individual differences influence sensorimotor learning. It is unknown whether imagery abilities influence both memory encoding and retrieval. We examined how auditory and motor imagery abilities influence musicians' encoding (during Learning, as they practiced novel melodies), and retrieval (during Recall of those melodies). Pianists learned melodies by listening without performing (auditory learning) or performing without sound (motor learning); following Learning, pianists performed the melodies from memory with auditory feedback (Recall). During either Learning (Experiment 1) or Recall (Experiment 2), pianists experienced either auditory interference, motor interference, or no interference. Pitch accuracy (percentage of correct pitches produced) and temporal regularity (variability of quarter-note interonset intervals) were measured at Recall. Independent tests measured auditory and motor imagery skills. Pianists' pitch accuracy was higher following auditory learning than following motor learning and lower in motor interference conditions (Experiments 1 and 2). Both auditory and motor imagery skills improved pitch accuracy overall. Auditory imagery skills modulated pitch accuracy encoding (Experiment 1): Higher auditory imagery skill corresponded to higher pitch accuracy following auditory learning with auditory or motor interference, and following motor learning with motor or no interference. These findings suggest that auditory imagery abilities decrease vulnerability to interference and compensate for missing auditory feedback at encoding. Auditory imagery skills also influenced temporal regularity at retrieval (Experiment 2): Higher auditory imagery skill predicted greater temporal regularity during Recall in the presence of

Auditory and motor imagery modulate learning in music performance

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Brown, Rachel M.; Palmer, Caroline

2013-01-01

Skilled performers such as athletes or musicians can improve their performance by imagining the actions or sensory outcomes associated with their skill. Performers vary widely in their auditory and motor imagery abilities, and these individual differences influence sensorimotor learning. It is unknown whether imagery abilities influence both memory encoding and retrieval. We examined how auditory and motor imagery abilities influence musicians' encoding (during Learning, as they practiced novel melodies), and retrieval (during Recall of those melodies). Pianists learned melodies by listening without performing (auditory learning) or performing without sound (motor learning); following Learning, pianists performed the melodies from memory with auditory feedback (Recall). During either Learning (Experiment 1) or Recall (Experiment 2), pianists experienced either auditory interference, motor interference, or no interference. Pitch accuracy (percentage of correct pitches produced) and temporal regularity (variability of quarter-note interonset intervals) were measured at Recall. Independent tests measured auditory and motor imagery skills. Pianists' pitch accuracy was higher following auditory learning than following motor learning and lower in motor interference conditions (Experiments 1 and 2). Both auditory and motor imagery skills improved pitch accuracy overall. Auditory imagery skills modulated pitch accuracy encoding (Experiment 1): Higher auditory imagery skill corresponded to higher pitch accuracy following auditory learning with auditory or motor interference, and following motor learning with motor or no interference. These findings suggest that auditory imagery abilities decrease vulnerability to interference and compensate for missing auditory feedback at encoding. Auditory imagery skills also influenced temporal regularity at retrieval (Experiment 2): Higher auditory imagery skill predicted greater temporal regularity during Recall in the presence of

Practicing field hockey skills along the contextual interference continuum: a comparison of five practice schedules.

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Cheong, Jadeera Phaik Geok; Lay, Brendan; Grove, J Robert; Medic, Nikola; Razman, Rizal

2012-01-01

To overcome the weakness of the contextual interference (CI) effect within applied settings, Brady, 2008 recommended that the amount of interference be manipulated. This study investigated the effect of five practice schedules on the learning of three field hockey skills. Fifty-five pre-university students performed a total of 90 trials for each skill under blocked, mixed or random practice orders. Results showed a significant time effect with all five practice conditions leading to improvements in acquisition and learning of the skills. No significant differences were found between the groups. The findings of the present study did not support the CI effect and suggest that either blocked, mixed, or random practice schedules can be used effectively when structuring practice for beginners. Key pointsThe contextual interference effect did not surface when using sport skills.There appears to be no difference between blocked and random practice schedules in the learning of field hockey skills.Low (blocked), moderate (mixed) or high (random) interference practice schedules can be used effectively when conducting a multiple skill practice session for beginners.

Rapid learning in practice: A lung cancer survival decision support system in routine patient care data

International Nuclear Information System (INIS)

Dekker, Andre; Vinod, Shalini; Holloway, Lois; Oberije, Cary; George, Armia; Goozee, Gary; Delaney, Geoff P.; Lambin, Philippe; Thwaites, David

2014-01-01

Background and purpose: A rapid learning approach has been proposed to extract and apply knowledge from routine care data rather than solely relying on clinical trial evidence. To validate this in practice we deployed a previously developed decision support system (DSS) in a typical, busy clinic for non-small cell lung cancer (NSCLC) patients. Material and methods: Gender, age, performance status, lung function, lymph node status, tumor volume and survival were extracted without review from clinical data sources for lung cancer patients. With these data the DSS was tested to predict overall survival. Results: 3919 lung cancer patients were identified with 159 eligible for inclusion, due to ineligible histology or stage, non-radical dose, missing tumor volume or survival. The DSS successfully identified a good prognosis group and a medium/poor prognosis group (2 year OS 69% vs. 27/30%, p < 0.001). Stage was less discriminatory (2 year OS 47% for stage I–II vs. 36% for stage IIIA–IIIB, p = 0.12) with most good prognosis patients having higher stage disease. The DSS predicted a large absolute overall survival benefit (∼40%) for a radical dose compared to a non-radical dose in patients with a good prognosis, while no survival benefit of radical radiotherapy was predicted for patients with a poor prognosis. Conclusions: A rapid learning environment is possible with the quality of clinical data sufficient to validate a DSS. It uses patient and tumor features to identify prognostic groups in whom therapy can be individualized based on predicted outcomes. Especially the survival benefit of a radical versus non-radical dose predicted by the DSS for various prognostic groups has clinical relevance, but needs to be prospectively validated

Interference from mere thinking: mental rehearsal temporarily disrupts recall of motor memory.

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Yin, Cong; Wei, Kunlin

2014-08-01

Interference between successively learned tasks is widely investigated to study motor memory. However, how simultaneously learned motor memories interact with each other has been rarely studied despite its prevalence in daily life. Assuming that motor memory shares common neural mechanisms with declarative memory system, we made unintuitive predictions that mental rehearsal, as opposed to further practice, of one motor memory will temporarily impair the recall of another simultaneously learned memory. Subjects simultaneously learned two sensorimotor tasks, i.e., visuomotor rotation and gain. They retrieved one memory by either practice or mental rehearsal and then had their memory evaluated. We found that mental rehearsal, instead of execution, impaired the recall of unretrieved memory. This impairment was content-independent, i.e., retrieving either gain or rotation impaired the other memory. Hence, conscious recollection of one motor memory interferes with the recall of another memory. This is analogous to retrieval-induced forgetting in declarative memory, suggesting a common neural process across memory systems. Our findings indicate that motor imagery is sufficient to induce interference between motor memories. Mental rehearsal, currently widely regarded as beneficial for motor performance, negatively affects memory recall when it is exercised for a subset of memorized items. Copyright © 2014 the American Physiological Society.

Working Conditions and Factory Survival: Evidence from Better Factories Cambodia

OpenAIRE

Robertson, Raymond; Brown, Drusilla; Dehejia, Rajeev

2016-01-01

A large and growing literature has identified several conditions, including exporting, that contribute to plant survival. A prevailing sentiment suggests that anti-sweatshop activity against plants in developing countries adds the risk of making survival more difficult by imposing external constraints that may interfere with optimizing behavior. Using a relatively new plant-level panel dataset from Cambodia, this paper applies survival analysis to estimate the relationship between changes in ...

The Price of Fame: The Impact of Stimulus Familiarity on Proactive Interference Resolution

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Prabhakaran, Ranjani; Thompson-Schill, Sharon L.

2011-01-01

Interference from previously learned information, known as proactive interference (PI), limits our memory retrieval abilities. Previous studies of PI resolution have focused on the role of short-term familiarity, or recency, in causing PI. In the present study, we investigated the impact of long-term stimulus familiarity on PI resolution…

Post-task Effects on EEG Brain Activity Differ for Various Differential Learning and Contextual Interference Protocols

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Diana Henz

2018-01-01

Full Text Available A large body of research has shown superior learning rates in variable practice compared to repetitive practice. More specifically, this has been demonstrated in the contextual interference (CI and in the differential learning (DL approach that are both representatives of variable practice. Behavioral studies have indicate different learning processes in CI and DL. Aim of the present study was to examine immediate post-task effects on electroencephalographic (EEG brain activation patterns after CI and DL protocols that reveal underlying neural processes at the early stage of motor consolidation. Additionally, we tested two DL protocols (gradual DL, chaotic DL to examine the effect of different degrees of stochastic fluctuations within the DL approach with a low degree of fluctuations in gradual DL and a high degree of fluctuations in chaotic DL. Twenty-two subjects performed badminton serves according to three variable practice protocols (CI, gradual DL, chaotic DL, and a repetitive learning protocol in a within-subjects design. Spontaneous EEG activity was measured before, and immediately after each 20-min practice session from 19 electrodes. Results showed distinguishable neural processes after CI, DL, and repetitive learning. Increases in EEG theta and alpha power were obtained in somatosensory regions (electrodes P3, P7, Pz, P4, P8 in both DL conditions compared to CI, and repetitive learning. Increases in theta and alpha activity in motor areas (electrodes C3, Cz, C4 were found after chaotic DL compared to gradual DL, and CI. Anterior areas (electrodes F3, F7, Fz, F4, F8 showed increased activity in the beta and gamma bands after CI. Alpha activity was increased in occipital areas (electrodes O1, O2 after repetitive learning. Post-task EEG brain activation patterns suggest that DL stimulates the somatosensory and motor system, and engages more regions of the cortex than repetitive learning due to a tighter stimulation of the motor and

Retrieval-induced forgetting and interference between cues: training a cue-outcome association attenuates retrieval by alternative cues.

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Ortega-Castro, Nerea; Vadillo, Miguel A

2013-03-01

Some researchers have attempted to determine whether situations in which a single cue is paired with several outcomes (A-B, A-C interference or interference between outcomes) involve the same learning and retrieval mechanisms as situations in which several cues are paired with a single outcome (A-B, C-B interference or interference between cues). Interestingly, current research on a related effect, which is known as retrieval-induced forgetting, can illuminate this debate. Most retrieval-induced forgetting experiments are based on an experimental design that closely resembles the A-B, A-C interference paradigm. In the present experiment, we found that a similar effect may be observed when items are rearranged such that the general structure of the task more closely resembles the A-B, C-B interference paradigm. This result suggests that, as claimed by other researchers in the area of contingency learning, the two types of interference, namely A-B, A-C and A-B, C-B interference, may share some basic mechanisms. Moreover, the type of inhibitory processes assumed to underlie retrieval-induced forgetting may also play a role in these phenomena. Copyright © 2012 Elsevier B.V. All rights reserved.

Interfering with theories of sleep and memory: sleep, declarative memory, and associative interference.

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Ellenbogen, Jeffrey M; Hulbert, Justin C; Stickgold, Robert; Dinges, David F; Thompson-Schill, Sharon L

2006-07-11

Mounting behavioral evidence in humans supports the claim that sleep leads to improvements in recently acquired, nondeclarative memories. Examples include motor-sequence learning; visual-discrimination learning; and perceptual learning of a synthetic language. In contrast, there are limited human data supporting a benefit of sleep for declarative (hippocampus-mediated) memory in humans (for review, see). This is particularly surprising given that animal models (e.g.,) and neuroimaging studies (e.g.,) predict that sleep facilitates hippocampus-based memory consolidation. We hypothesized that we could unmask the benefits of sleep by challenging the declarative memory system with competing information (interference). This is the first study to demonstrate that sleep protects declarative memories from subsequent associative interference, and it has important implications for understanding the neurobiology of memory consolidation.

The interference effects of non-rotated versus counter-rotated trials in visuomotor adaptation.

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Hinder, Mark R; Walk, Laura; Woolley, Daniel G; Riek, Stephan; Carson, Richard G

2007-07-01

An isometric torque-production task was used to investigate interference and retention in adaptation to multiple visuomotor environments. Subjects produced isometric flexion-extension and pronation-supination elbow torques to move a cursor to acquire targets as quickly as possible. Adaptation to a 30 degrees counter-clockwise (CCW) rotation (task A), was followed by a period of rest (control), trials with no rotation (task B0), or trials with a 60 degrees clockwise (CW) rotation (task B60). For all groups, retention of task A was assessed 5 h later. With initial training, all groups reduced the angular deviation of cursor paths early in the movements, indicating feedforward adaptation. For the control group, performance at commencement of the retest was significantly better than that at the beginning of the initial learning. For the B0 group, performance in the retest of task A was not dissimilar to that at the start of the initial learning, while for the B60 group retest performance in task A was markedly worse than initially observed. Our results indicate that close juxtaposition of two visuomotor environments precludes improved retest performance in the initial environment. Data for the B60 group, specifically larger angular errors upon retest compared with initial exposures, are consistent with the presence of anterograde interference. Furthermore, full interference occurred even when the visuomotor environment encountered in the second task was not rotated (B0). This latter novel result differs from those obtained for force field learning, where interference does not occur when task B does not impose perturbing forces, i.e., when B consists of a null field (Brashers-Krug et al., Nature 382:252-255, 1996). The results are consistent with recent proposals suggesting different interference mechanisms for visuomotor (kinematic) compared to force field (dynamic) adaptations, and have implications for the use of washout trials when studying interference between

Consolidation through the looking-glass: sleep-dependent proactive interference on visuomotor adaptation in children.

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Urbain, Charline; Houyoux, Emeline; Albouy, Geneviève; Peigneux, Philippe

2014-02-01

Although a beneficial role of post-training sleep for declarative memory has been consistently evidenced in children, as in adults, available data suggest that procedural memory consolidation does not benefit from sleep in children. However, besides the absence of performance gains in children, sleep-dependent plasticity processes involved in procedural memory consolidation might be expressed through differential interference effects on the learning of novel but related procedural material. To test this hypothesis, 32 10-12-year-old children were trained on a motor rotation adaptation task. After either a sleep or a wake period, they were first retested on the same rotation applied at learning, thus assessing offline sleep-dependent changes in performance, then on the opposite (unlearned) rotation to assess sleep-dependent modulations in proactive interference coming from the consolidated visuomotor memory trace. Results show that children gradually improve performance over the learning session, showing effective adaptation to the imposed rotation. In line with previous findings, no sleep-dependent changes in performance were observed for the learned rotation. However, presentation of the opposite, unlearned deviation elicited significantly higher interference effects after post-training sleep than wakefulness in children. Considering that a definite feature of procedural motor memory and skill acquisition is the implementation of highly automatized motor behaviour, thus lacking flexibility, our results suggest a better integration and/or automation or motor adaptation skills after post-training sleep, eventually resulting in higher proactive interference effects on untrained material. © 2013 European Sleep Research Society.

Motor Interference Does Not Impair the Memory Consolidation of Imagined Movements

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Debarnot, Ursula; Maley, Laura; De Rossi, Danilo; Guillot, Aymeric

2010-01-01

The present study aimed to investigate whether an interference task might impact the sleep-dependent consolidation process of a mentally learned sequence of movements. Thirty-two participants were subjected to a first training session through motor imagery (MI) or physical practice (PP) of a finger sequence learning task. After 2 h, half of the…

Auditory and motor imagery modulate learning in music performance

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Rachel M. Brown

2013-07-01

Full Text Available Skilled performers such as athletes or musicians can improve their performance by imagining the actions or sensory outcomes associated with their skill. Performers vary widely in their auditory and motor imagery abilities, and these individual differences influence sensorimotor learning. It is unknown whether imagery abilities influence both memory encoding and retrieval. We examined how auditory and motor imagery abilities influence musicians’ encoding (during Learning, as they practiced novel melodies, and retrieval (during Recall of those melodies. Pianists learned melodies by listening without performing (auditory learning or performing without sound (motor learning; following Learning, pianists performed the melodies from memory with auditory feedback (Recall. During either Learning (Experiment 1 or Recall (Experiment 2, pianists experienced either auditory interference, motor interference, or no interference. Pitch accuracy (percentage of correct pitches produced and temporal regularity (variability of quarter-note interonset intervals were measured at Recall. Independent tests measured auditory and motor imagery skills. Pianists’ pitch accuracy was higher following auditory learning than following motor learning and lower in motor interference conditions (Experiments 1 and 2. Both auditory and motor imagery skills improved pitch accuracy overall. Auditory imagery skills modulated pitch accuracy encoding (Experiment 1: Higher auditory imagery skill corresponded to higher pitch accuracy following auditory learning with auditory or motor interference, and following motor learning with motor or no interference. These findings suggest that auditory imagery abilities decrease vulnerability to interference and compensate for missing auditory feedback at encoding. Auditory imagery skills also influenced temporal regularity at retrieval (Experiment 2: Higher auditory imagery skill predicted greater temporal regularity during Recall in the

A natural form of learning can increase and decrease the survival of new neurons in the dentate gyrus.

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Olariu, Ana; Cleaver, Kathryn M; Shore, Lauren E; Brewer, Michelle D; Cameron, Heather A

2005-01-01

Granule cells born in the adult dentate gyrus undergo a 4-week developmental period characterized by high susceptibility to cell death. Two forms of hippocampus-dependent learning have been shown to rescue many of the new neurons during this critical period. Here, we show that a natural form of associative learning, social transmission of food preference (STFP), can either increase or decrease the survival of young granule cells in adult rats. Increased numbers of pyknotic as well as phospho-Akt-expressing BrdU-labeled cells were seen 1 day after STFP training, indicating that training rapidly induces both cell death and active suppression of cell death in different subsets. A single day of training for STFP increased the survival of 8-day-old BrdU-labeled cells when examined 1 week later. In contrast, 2 days of training decreased the survival of BrdU-labeled cells and the density of immature neurons, identified with crmp-4. This change from increased to decreased survival could not be accounted for by the ages of the cells. Instead, we propose that training may initially increase young granule cell survival, then, if continued, cause them to die. This complex regulation of cell death could potentially serve to maintain granule cells that are actively involved in memory consolidation, while rapidly using and discarding young granule cells whose training is complete to make space for new naïve neurons. Published 2005 Wiley-Liss, Inc.

Proactive Interference and Directed Forgetting in Short-Term Motor Memory

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Burwitz, Leslie

1974-01-01

The present study was designed to test the effect of instructions to forget prior motor learning and the results were relevant to the understanding of short-term motor memory (STMM) proactive interference (PI). (Author/RK)

Impaired memory for material related to a problem solved prior to encoding: suppression at learning or interference at recall?

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Kowalczyk, Marek

2017-07-01

Earlier research by the author revealed that material encoded incidentally in a speeded affective classification task and related to the demands of a divergent problem tends to be recalled worse in participants who solved the problem prior to encoding than in participants in the control, no-problem condition. The aim of the present experiment was to replicate this effect with a new, size-comparison orienting task, and to test for possible mechanisms of impaired recall. Participants either solved a problem before the orienting task or not, and classified each item in this task either once or three times. There was a reliable effect of impaired recall of problem-related items in the repetition condition, but not in the no-repetition condition. Solving the problem did not influence repetition priming for these items. These results support an account that attributes the impaired recall to inhibitory processes at learning and speak against a proactive interference explanation. However, they can be also accommodated by an account that refers to inefficient context cues and competitor interference at retrieval.

Survival analysis models and applications

CERN Document Server

Liu, Xian

2012-01-01

Survival analysis concerns sequential occurrences of events governed by probabilistic laws.  Recent decades have witnessed many applications of survival analysis in various disciplines. This book introduces both classic survival models and theories along with newly developed techniques. Readers will learn how to perform analysis of survival data by following numerous empirical illustrations in SAS. Survival Analysis: Models and Applications: Presents basic techniques before leading onto some of the most advanced topics in survival analysis.Assumes only a minimal knowledge of SAS whilst enablin

Interference Conditions of the Reconsolidation Process in Humans: The Role of Valence and Different Memory Systems.

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Fernández, Rodrigo S; Bavassi, Luz; Kaczer, Laura; Forcato, Cecilia; Pedreira, María E

2016-01-01

Following the presentation of a reminder, consolidated memories become reactivated followed by a process of re-stabilization, which is referred to as reconsolidation. The most common behavioral tool used to reveal this process is interference produced by new learning shortly after memory reactivation. Memory interference is defined as a decrease in memory retrieval, the effect is generated when new information impairs an acquired memory. In general, the target memory and the interference task used are the same. Here we investigated how different memory systems and/or their valence could produce memory reconsolidation interference. We showed that a reactivated neutral declarative memory could be interfered by new learning of a different neutral declarative memory. Then, we revealed that an aversive implicit memory could be interfered by the presentation of a reminder followed by a threatening social event. Finally, we showed that the reconsolidation of a neutral declarative memory is unaffected by the acquisition of an aversive implicit memory and conversely, this memory remains intact when the neutral declarative memory is used as interference. These results suggest that the interference of memory reconsolidation is effective when two task rely on the same memory system or both evoke negative valence.

Testing can counteract proactive interference by integrating competing information

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Wahlheim, Christopher N.

2015-01-01

Testing initially learned information before presenting new information has been shown to counteract the deleterious effects of proactive interference by segregating competing sources of information. The present experiments were conducted to demonstrate that testing can also have its effects in part by integrating competing information. Variations of classic A–B, A–D paired-associate learning paradigms were employed that included two lists of word pairs and a cued-recall test. Repeated pairs appeared in both lists (A–B, A–B), control pairs appeared in List 2 only (A–B, C–D), and changed pairs appeared with the same cue in both lists but with different responses (A–B, A–D). The critical manipulation was whether pairs were tested or restudied in an interpolated phase that occurred between Lists 1 and 2. On a final cued-recall test, participants recalled List 2 responses and then indicated when they recollected that responses had earlier changed between lists. The change recollection measure indexed the extent to which competing responses were integrated during List 2. Change was recollected more often for tested than for restudied pairs. Proactive facilitation was obtained in cued recall when change was recollected, whereas proactive interference was obtained when change was not recollected. These results provide evidence that testing counteracted proactive interference in part by making List 1 responses more accessible during List 2, thus promoting integration and increasing later recollection of change. These results have theoretical implications because they show that testing can counteract proactive interference by integrating or segregating competing information. PMID:25120241

Testing can counteract proactive interference by integrating competing information.

Science.gov (United States)

Wahlheim, Christopher N

2015-01-01

Testing initially learned information before presenting new information has been shown to counteract the deleterious effects of proactive interference by segregating competing sources of information. The present experiments were conducted to demonstrate that testing can also have its effects in part by integrating competing information. Variations of classic A-B, A-D paired-associate learning paradigms were employed that included two lists of word pairs and a cued-recall test. Repeated pairs appeared in both lists (A-B, A-B), control pairs appeared in List 2 only (A-B, C-D), and changed pairs appeared with the same cue in both lists but with different responses (A-B, A-D). The critical manipulation was whether pairs were tested or restudied in an interpolated phase that occurred between Lists 1 and 2. On a final cued-recall test, participants recalled List 2 responses and then indicated when they recollected that responses had earlier changed between lists. The change recollection measure indexed the extent to which competing responses were integrated during List 2. Change was recollected more often for tested than for restudied pairs. Proactive facilitation was obtained in cued recall when change was recollected, whereas proactive interference was obtained when change was not recollected. These results provide evidence that testing counteracted proactive interference in part by making List 1 responses more accessible during List 2, thus promoting integration and increasing later recollection of change. These results have theoretical implications because they show that testing can counteract proactive interference by integrating or segregating competing information.

Timing of presentation and nature of stimuli determine retroactive interference with social recognition memory in mice.

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Perna, Judith Camats; Wotjak, Carsten T; Stork, Oliver; Engelmann, Mario

2015-05-01

The present study was designed to further investigate the nature of stimuli and the timing of their presentation, which can induce retroactive interference with social recognition memory in mice. In accordance with our previous observations, confrontation with an unfamiliar conspecific juvenile 3h and 6h, but not 22 h, after the initial learning session resulted in retroactive interference. The same effect was observed with the exposure to both enantiomers of the monomolecular odour carvone, and with a novel object. Exposure to a loud tone (12 KHz, 90 dB) caused retroactive interference at 6h, but not 3h and 22 h, after sampling. Our data show that retroactive interference of social recognition memory can be induced by exposing the experimental subjects to the defined stimuli presented <22 h after learning in their home cage. The distinct interference triggered by the tone presentation at 6h after sampling may be linked to the intrinsic aversiveness of the loud tone and suggests that at this time point memory consolidation is particularly sensitive to stress. Copyright © 2015 Elsevier Inc. All rights reserved.

RELATIONSHIP BETWEEN PERCEPTION AND LEARNING IN THE MENTALLY RETARDED.

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JOHNSON, G. ORVILLE

SUPPORTIVE EVIDENCE IS GIVEN AGAINST PERCEPTUAL DISORDERS CREATING INTERFERENCE IN LEARNING. THE CONTENTION THAT A PERCEPTUAL FIGURE GROUND DISTURBANCE NECESSARILY INTERFERES WITH THE LEARNING PROCESS IS NOT SUPPORTED BY THE EVIDENCE. THERE ARE INDICATIONS, HOWEVER, THAT BACKGROUND INTERFERENCE SEEMS TO AFFECT SOME CHILDREN MORE THAN OTHERS. TWO…

Retrieval-induced forgetting and interference between cues:Training a cue-outcome association attenuates retrieval by alternative cues

OpenAIRE

Ortega-Castro, Nerea; Vadillo Nistal, Miguel

2013-01-01

Some researchers have attempted to determine whether situations in which a single cue is paired with several outcomes (A-B, A-C interference or interference between outcomes) involve the same learning and retrieval mechanisms as situations in which several cues are paired with a single outcome (A-B, C-B interference or interference between cues). Interestingly, current research on a related effect, which is known as retrieval-induced forgetting, can illuminate this debate. Most retrieval-indu...

Chemical and physical effects of crowding on growth and survival of Penaeus monodon Fabricius post-larvae

NARCIS (Netherlands)

Nga, B.T.; Lürling, M.F.L.L.W.; Peeters, E.T.H.M.; Roijackers, R.M.M.; Scheffer, M.; Nghia, T.T.

2005-01-01

The hypothesis that crowding effects through physical and/or chemical interference may be an important factor in lowering the chance of survival and reducing growth of Penaeus monodon post-larvae under high stocking densities was tested. To separate physical interference from chemically-exerted

Magnetic stimulation of visual cortex impairs perceptual learning.

Science.gov (United States)

Baldassarre, Antonello; Capotosto, Paolo; Committeri, Giorgia; Corbetta, Maurizio

2016-12-01

The ability to learn and process visual stimuli more efficiently is important for survival. Previous neuroimaging studies have shown that perceptual learning on a shape identification task differently modulates activity in both frontal-parietal cortical regions and visual cortex (Sigman et al., 2005;Lewis et al., 2009). Specifically, fronto-parietal regions (i.e. intra parietal sulcus, pIPS) became less activated for trained as compared to untrained stimuli, while visual regions (i.e. V2d/V3 and LO) exhibited higher activation for familiar shape. Here, after the intensive training, we employed transcranial magnetic stimulation over both visual occipital and parietal regions, previously shown to be modulated, to investigate their causal role in learning the shape identification task. We report that interference with V2d/V3 and LO increased reaction times to learned stimuli as compared to pIPS and Sham control condition. Moreover, the impairment observed after stimulation over the two visual regions was positive correlated. These results strongly support the causal role of the visual network in the control of the perceptual learning. Copyright © 2016 Elsevier Inc. All rights reserved.

Interference conditions of the reconsolidation process in humans: the role of valence and different memory systems.

OpenAIRE

Rodrigo S Fernández; Luz Bavassi; Luz Bavassi; Laura Kaczer; Cecilia Forcato; María Eugenia Pedreira

2016-01-01

Following the presentation of a reminder, consolidated memories become reactivated followed by a process of re-stabilization, which is referred to as reconsolidation. The most common behavioral tool used to reveal this process is interference produced by new learning shortly after memory reactivation. Memory interference is defined as a decrease in memory retrieval, the effect is generated when new information impairs an acquired memory. In general, the target memory and the interference task...

Enhanced conditioned eyeblink response acquisition and proactive interference in anxiety vulnerable individuals

Directory of Open Access Journals (Sweden)

Jacqueline L Holloway

2012-11-01

Full Text Available In classical conditioning, proactive interference may arise from experience with the conditioned stimulus (CS, the unconditional stimulus (US, or both, prior to their paired presentations. Interest in the application of proactive interference has extended to clinical populations as either a risk factor for disorders or as a secondary sign. Although the current literature is dense with comparisons of stimulus pre-exposure effects in animals, such comparisons are lacking in human subjects. As such, interpretation of proactive interference over studies as well as its generalization and utility in clinical research is limited. The present study was designed to assess eyeblink response acquisition after equal numbers of CS, US, and explicitly unpaired CS and US pre-exposures, as well as to evaluate how anxiety vulnerability might modulate proactive interference. In the current study, anxiety vulnerability was assessed using the State/Trait Anxiety Inventories as well as the adult and retrospective measures of behavioural inhibition (AMBI and RMBI, respectively. Participants were exposed to 1 of 4 possible pre-exposure contingencies: 30 CS, 30 US, 30 CS and 30 US explicitly unpaired pre-exposures, or context pre-exposure, immediately prior to standard delay training. Robust proactive interference was evident in all pre-exposure groups relative to context pre-exposure, independent of anxiety classification, with CR acquisition attenuated at similar rates. In addition, trait anxious individuals were found to have enhanced overall acquisition as well as greater proactive interference relative to non-vulnerable individuals. The findings suggest that anxiety vulnerable individuals learn implicit associations faster, an effect which persists after the introduction of new stimulus contingencies. This effect is not due to enhanced sensitivity to the US. Such differences would have implications for the development of anxiety psychopathology within a learning

Enhanced conditioned eyeblink response acquisition and proactive interference in anxiety vulnerable individuals.

Science.gov (United States)

Holloway, Jacqueline L; Trivedi, Payal; Myers, Catherine E; Servatius, Richard J

2012-01-01

In classical conditioning, proactive interference may arise from experience with the conditioned stimulus (CS), the unconditional stimulus (US), or both, prior to their paired presentations. Interest in the application of proactive interference has extended to clinical populations as either a risk factor for disorders or as a secondary sign. Although the current literature is dense with comparisons of stimulus pre-exposure effects in animals, such comparisons are lacking in human subjects. As such, interpretation of proactive interference over studies as well as its generalization and utility in clinical research is limited. The present study was designed to assess eyeblink response acquisition after equal numbers of CS, US, and explicitly unpaired CS and US pre-exposures, as well as to evaluate how anxiety vulnerability might modulate proactive interference. In the current study, anxiety vulnerability was assessed using the State/Trait Anxiety Inventories as well as the adult and retrospective measures of behavioral inhibition (AMBI and RMBI, respectively). Participants were exposed to 1 of 4 possible pre-exposure contingencies: 30 CS, 30 US, 30 CS, and 30 US explicitly unpaired pre-exposures, or Context pre-exposure, immediately prior to standard delay training. Robust proactive interference was evident in all pre-exposure groups relative to Context pre-exposure, independent of anxiety classification, with CR acquisition attenuated at similar rates. In addition, trait anxious individuals were found to have enhanced overall acquisition as well as greater proactive interference relative to non-vulnerable individuals. The findings suggest that anxiety vulnerable individuals learn implicit associations faster, an effect which persists after the introduction of new stimulus contingencies. This effect is not due to enhanced sensitivity to the US. Such differences would have implications for the development of anxiety psychopathology within a learning framework.

Probability cueing of distractor locations: both intertrial facilitation and statistical learning mediate interference reduction.

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Goschy, Harriet; Bakos, Sarolta; Müller, Hermann J; Zehetleitner, Michael

2014-01-01

Targets in a visual search task are detected faster if they appear in a probable target region as compared to a less probable target region, an effect which has been termed "probability cueing." The present study investigated whether probability cueing cannot only speed up target detection, but also minimize distraction by distractors in probable distractor regions as compared to distractors in less probable distractor regions. To this end, three visual search experiments with a salient, but task-irrelevant, distractor ("additional singleton") were conducted. Experiment 1 demonstrated that observers can utilize uneven spatial distractor distributions to selectively reduce interference by distractors in frequent distractor regions as compared to distractors in rare distractor regions. Experiments 2 and 3 showed that intertrial facilitation, i.e., distractor position repetitions, and statistical learning (independent of distractor position repetitions) both contribute to the probability cueing effect for distractor locations. Taken together, the present results demonstrate that probability cueing of distractor locations has the potential to serve as a strong attentional cue for the shielding of likely distractor locations.

Beamforming design with proactive interference cancelation in MISO interference channels

Science.gov (United States)

Li, Yang; Tian, Yafei; Yang, Chenyang

2015-12-01

In this paper, we design coordinated beamforming at base stations (BSs) to facilitate interference cancelation at users in interference networks, where each BS is equipped with multiple antennas and each user is with a single antenna. By assuming that each user can select the best decoding strategy to mitigate the interference, either canceling the interference after decoding when it is strong or treating it as noise when it is weak, we optimize the beamforming vectors that maximize the sum rate for the networks under different interference scenarios and find the solutions of beamforming with closed-form expressions. The inherent design principles are then analyzed, and the performance gain over passive interference cancelation is demonstrated through simulations in heterogeneous cellular networks.

Survival Processing and the Stroop Task

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Stephanie A. Kazanas

2015-11-01

Full Text Available This study was designed to investigate the impact of survival processing with a novel task for this paradigm: the Stroop color-naming task. As the literature is mixed with regard to task generalizability, with survival processing promoting better memory for words, but not better memory for faces or paired associates, these types of task investigations are important to a growing field of research. Using the Stroop task provides a unique contribution, as identifying items by color is an important evolutionary adaptation and not specific to humans as is the case with word recall. Our results indicate that survival processing, with its accompanying survival-relevance rating task, remains the best mnemonic strategy for word memory. However, our results also indicate that presenting the survival passage does not motivate better color-naming performance than color-naming alone. In addition, survival processing led to a larger amount of Stroop interference, though not significantly larger than the other conditions. Together, these findings suggest that considering one’s survival when performing memory and attention-based tasks does not enhance cognitive performance generally, although greater allocation of attentional resources to color-incongruent concrete objects could be considered adaptive. These findings support the notion that engaging in deeper processing via survival-relevance ratings may preserve these words across a variety of experimental manipulations.

A comparative study of machine learning methods for time-to-event survival data for radiomics risk modelling.

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Leger, Stefan; Zwanenburg, Alex; Pilz, Karoline; Lohaus, Fabian; Linge, Annett; Zöphel, Klaus; Kotzerke, Jörg; Schreiber, Andreas; Tinhofer, Inge; Budach, Volker; Sak, Ali; Stuschke, Martin; Balermpas, Panagiotis; Rödel, Claus; Ganswindt, Ute; Belka, Claus; Pigorsch, Steffi; Combs, Stephanie E; Mönnich, David; Zips, Daniel; Krause, Mechthild; Baumann, Michael; Troost, Esther G C; Löck, Steffen; Richter, Christian

2017-10-16

Radiomics applies machine learning algorithms to quantitative imaging data to characterise the tumour phenotype and predict clinical outcome. For the development of radiomics risk models, a variety of different algorithms is available and it is not clear which one gives optimal results. Therefore, we assessed the performance of 11 machine learning algorithms combined with 12 feature selection methods by the concordance index (C-Index), to predict loco-regional tumour control (LRC) and overall survival for patients with head and neck squamous cell carcinoma. The considered algorithms are able to deal with continuous time-to-event survival data. Feature selection and model building were performed on a multicentre cohort (213 patients) and validated using an independent cohort (80 patients). We found several combinations of machine learning algorithms and feature selection methods which achieve similar results, e.g. C-Index = 0.71 and BT-COX: C-Index = 0.70 in combination with Spearman feature selection. Using the best performing models, patients were stratified into groups of low and high risk of recurrence. Significant differences in LRC were obtained between both groups on the validation cohort. Based on the presented analysis, we identified a subset of algorithms which should be considered in future radiomics studies to develop stable and clinically relevant predictive models for time-to-event endpoints.

Interference between perennial grassland and Lavandula stoechas subsp. pedunculata seedlings: a case of spatial segregation cause by competition

Science.gov (United States)

Sánchez, Ana M.; Peco, Begoña

2004-07-01

This paper analyses the relationship between Lavandula stoechas subsp. pedunculata, a common Mediterranean scrub species in central Iberia, and perennial grasslands. While Lavandula gives rise to almost monospecific formations in intermediate and upper hill zones, perennial grasses occupy the low areas. The proposed explanatory hypothesis for this spatial distribution is that the scrub is unable to establish itself in grasslands with heavy spatial occupation. We designed two experiments to test this hypothesis, one which analysed the effect of perennial grass cover on Lavandula establishment, and another which focused on its influence on previously implanted seedling survival and growth, distinguishing the effect of shoot and root interference. The results show negative interference during establishment and later in the use of light and nutrients. This results in a very low overall survival probability, with only 1.4% of seedlings surviving the first growth period. This low success rate explains the existence of a clear spatial segregation between scrub patches and perennial-dominated grasslands.

Does my high blood pressure improve your survival? Overall and subgroup learning curves in health.

Science.gov (United States)

Van Gestel, Raf; Müller, Tobias; Bosmans, Johan

2017-09-01

Learning curves in health are of interest for a wide range of medical disciplines, healthcare providers, and policy makers. In this paper, we distinguish between three types of learning when identifying overall learning curves: economies of scale, learning from cumulative experience, and human capital depreciation. In addition, we approach the question of how treating more patients with specific characteristics predicts provider performance. To soften collinearity problems, we explore the use of least absolute shrinkage and selection operator regression as a variable selection method and Theil-Goldberger mixed estimation to augment the available information. We use data from the Belgian Transcatheter Aorta Valve Implantation (TAVI) registry, containing information on the first 860 TAVI procedures in Belgium. We find that treating an additional TAVI patient is associated with an increase in the probability of 2-year survival by about 0.16%-points. For adverse events like renal failure and stroke, we find that an extra day between procedures is associated with an increase in the probability for these events by 0.12%-points and 0.07%-points, respectively. Furthermore, we find evidence for positive learning effects from physicians' experience with defibrillation, treating patients with hypertension, and the use of certain types of replacement valves during the TAVI procedure. Copyright © 2017 John Wiley & Sons, Ltd.

Cognitive control of familiarity: directed forgetting reduces proactive interference in working memory.

Science.gov (United States)

Festini, Sara B; Reuter-Lorenz, Patricia A

2014-03-01

Proactive interference (PI) occurs when previously learned information interferes with new learning. In a working memory task, PI induces longer response times and more errors to recent negative probes than to new probes, presumably because the recent probe's familiarity invites a "yes" response. Warnings, longer intertrial intervals, and the increased contextual salience of the probes can reduce but not eliminate PI, suggesting that cognitive control over PI is limited. Here we tested whether control exerted in the form of intentional forgetting performed during working memory can reduce the magnitude of PI. In two experiments, participants performed a working memory task with directed-forgetting instructions and the occasional presentation of recent probes. Surprise long-term memory testing indicated better memory for to-be-remembered than for to-be-forgotten items, documenting the classic directed-forgetting effect. Critically, in working memory, PI was virtually eliminated for recent probes from prior to-be-forgotten lists, as compared to recent probes from prior to-be-remembered lists. Thus cognitive control, when executed via directed forgetting, can reduce the adverse and otherwise persistent interference from familiarity, an effect that we attribute to attenuated memory representations of the to-be-forgotten items.

Continuous executive function disruption interferes with application of an information integration categorization strategy.

Science.gov (United States)

Miles, Sarah J; Matsuki, Kazunaga; Minda, John Paul

2014-07-01

Category learning is often characterized as being supported by two separate learning systems. A verbal system learns rule-defined (RD) categories that can be described using a verbal rule and relies on executive functions (EFs) to learn via hypothesis testing. A nonverbal system learns non-rule-defined (NRD) categories that cannot be described by a verbal rule and uses automatic, procedural learning. The verbal system is dominant in that adults tend to use it during initial learning but may switch to the nonverbal system when the verbal system is unsuccessful. The nonverbal system has traditionally been thought to operate independently of EFs, but recent studies suggest that EFs may play a role in the nonverbal system-specifically, to facilitate the transition away from the verbal system. Accordingly, continuously interfering with EFs during the categorization process, so that EFs are never fully available to facilitate the transition, may be more detrimental to the nonverbal system than is temporary EF interference. Participants learned an NRD or an RD category while EFs were untaxed, taxed temporarily, or taxed continuously. When EFs were continuously taxed during NRD categorization, participants were less likely to use a nonverbal categorization strategy than when EFs were temporarily taxed, suggesting that when EFs were unavailable, the transition to the nonverbal system was hindered. For the verbal system, temporary and continuous interference had similar effects on categorization performance and on strategy use, illustrating that EFs play an important but different role in each of the category-learning systems.

SURVIVAL STRATEGIES OF MICROENTREPRENEURS IN SOUTHERN MEXICO CITY: INFLUENCE OF APPRECIATED LEARNING

Directory of Open Access Journals (Sweden)

Arcelia López-Cabello

2015-07-01

Full Text Available The strategies of family reproduction are various ways in which families cope with the problems of everyday life, where the preservation of life and development of essential economic practices is ensured to optimize the material and non-material conditions of the family unit and of each of its members. Through in-depth interviews it was learned how some microentrepreneurs in Mexico City, have used their knowledge appreciated to implement various business generates economic resources to survive, but also have inherited the children. Technical and family secrets on how to make some product knowledge are transmitted from generation to generation, and part of the heritage of a family, becoming livelihood strategies.

Stage-specific predictive models for breast cancer survivability.

Science.gov (United States)

Kate, Rohit J; Nadig, Ramya

2017-01-01

Survivability rates vary widely among various stages of breast cancer. Although machine learning models built in past to predict breast cancer survivability were given stage as one of the features, they were not trained or evaluated separately for each stage. To investigate whether there are differences in performance of machine learning models trained and evaluated across different stages for predicting breast cancer survivability. Using three different machine learning methods we built models to predict breast cancer survivability separately for each stage and compared them with the traditional joint models built for all the stages. We also evaluated the models separately for each stage and together for all the stages. Our results show that the most suitable model to predict survivability for a specific stage is the model trained for that particular stage. In our experiments, using additional examples of other stages during training did not help, in fact, it made it worse in some cases. The most important features for predicting survivability were also found to be different for different stages. By evaluating the models separately on different stages we found that the performance widely varied across them. We also demonstrate that evaluating predictive models for survivability on all the stages together, as was done in the past, is misleading because it overestimates performance. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The paca that roared: Immediate cumulative semantic interference among newly acquired words.

Science.gov (United States)

Oppenheim, Gary M

2018-08-01

With 40,000 words in the average vocabulary, how can speakers find the specific words that they want so quickly and easily? Cumulative semantic interference in language production provides a clue: when naming a large series of pictures, with a few mammals sprinkled about, naming each subsequent mammal becomes slower and more error-prone. Such interference mirrors predictions from an incremental learning algorithm applied to meaning-driven retrieval from an established vocabulary, suggesting retrieval benefits from a constant, implicit, re-optimization process (Oppenheim et al., 2010). But how quickly would a new mammal (e.g. paca) engage in this re-optimization? In this experiment, 18 participants studied 3 novel and 3 familiar exemplars from each of six semantic categories, and immediately performed a timed picture-naming task. Consistent with the learning model's predictions, naming latencies revealed immediate cumulative semantic interference in all directions: from new words to new words, from new words to old words, from old words to new words, and from old words to old words. Repeating the procedure several days later produced similar-magnitude effects, demonstrating that newly acquired words can be immediately semantically integrated, at least to the extent necessary to produce typical cumulative semantic interference. These findings extend the Dark Side model's scope to include novel word production, and are considered in terms of mechanisms for lexical selection. Copyright © 2018 Elsevier B.V. All rights reserved.

Escaping the recent past: which stimulus dimensions influence proactive interference?

Science.gov (United States)

Craig, Kimberly S; Berman, Marc G; Jonides, John; Lustig, Cindy

2013-07-01

Proactive interference occurs when information from the past disrupts current processing and is a major source of confusion and errors in short-term memory (STM; Wickens, Born, & Allen, Journal of Verbal Learning and Verbal Behavior, 2:440-445, 1963). The present investigation examines potential boundary conditions for interference, testing the hypothesis that potential competitors must be similar along task-relevant dimensions to influence proactive interference effects. We manipulated both the type of task being completed (Experiments 1, 2, and 3) and dimensions of similarity irrelevant to the current task (Experiments 4 and 5) to determine how the recent presentation of a probe item would affect the speed with which participants could reject that item. Experiments 1, 2, and 3 contrasted STM judgments, which require temporal information, with semantic and perceptual judgments, for which temporal information is irrelevant. In Experiments 4 and 5, task-irrelevant information (perceptual similarity) was manipulated within the recent probes task. We found that interference from past items affected STM task performance but did not affect performance in semantic or perceptual judgment tasks. Conversely, similarity along a nominally irrelevant perceptual dimension did not affect the magnitude of interference in STM tasks. Results are consistent with the view that items in STM are represented by noisy codes consisting of multiple dimensions and that interference occurs when items are similar to each other and, thus, compete along the dimensions relevant to target selection.

The effects of a single bout of exercise on motor memory interference in the trained and untrained hemisphere.

Science.gov (United States)

Lauber, Benedikt; Franke, Steffen; Taube, Wolfgang; Gollhofer, Albert

2017-04-07

Increasing evidence suggests that cardiovascular exercise has positive effects on motor memory consolidation. In this study, we investigated whether a single session of high-intensity interval training (HIIT) mitigates the effects of practicing an interfering motor task. Furthermore, learning and interference effects were assessed in the actively trained and untrained limb as it is known that unilateral motor learning can cause bilateral adaptations. Subjects performed a ballistic training and then the HIIT either before (HIIT_before) or after (HIIT_after) practicing an interfering accuracy task (AT). The control group (No_HIIT) did not participate in the HIIT but rested instead. Performance in the ballistic task (BT) was tested before and after the ballistic training, after the exercise and practice of the AT and 24h later. After ballistic training, all groups showed comparable increases in performance in the trained and untrained limb. Despite the practice of the AT, HIIT_before maintained their BT performance after the high-intensity interval training whereas HIIT_after (trend) & No_HIIT showed prominent interference effects. After 24h, HIIT_before still did not show any interference effects but further improved ballistic motor performance. HIIT_after counteracted the interference resulting in a comparable BT performance after 24h than directly after the ballistic training while No_HIIT had a significantly lower BT performance in the retention test. The results were similar in the trained and untrained limb. The current results imply that a single session of cardiovascular exercise can prevent motor interference in the trained and untrained hemisphere. Overall learning was best, and interference least, when HIIT was performed before the interfering motor task. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Experimental occlusal interferences. Part III. Mandibular rotations induced by a rigid interference.

Science.gov (United States)

Rassouli, N M; Christensen, L V

1995-10-01

A rigid intercuspal interference (minimum mean height of 0.24 mm) was placed on either the right or left mandibular second premolar and first molar of 12 subjects. During brisk and forceful biting on the interference, rotational electrognathography measured maximum torque of the right and left mandibular condyles in the frontal and horizontal planes of orientation. All subjects showed frontal plan upward rotation (mean of 0.7 degrees) of the mandibular condyle contralateral to the interference. In 33% of the subjects there was no horizontal plane backward rotation. In 58% of the subjects there was horizontal plane backward rotation (mean of 0.5 degrees) of the mandibular condyle ipsilateral to the interference, and in one subject (8%) there was backward horizontal plane rotation (0.1 degree) of the mandibular condyle contralateral to the interference. It was inferred that the masseter muscle, ipsilateral to the interference, generated negative work in order to decelerate frontal plane 'unseating' of the mandibular condyle ipsilateral to the interference. It was inferred that the masseter muscle, contralateral to the interference, produced positive work in order to accelerate frontal plane 'seating' of the mandibular condyle contralateral to the interference. Finally, it was speculated that the impact forces of frontal plane 'seating' of the mandibular condyle, contralateral to the interference, might lead to 'vacuum sticking' of the temporomandibular joint disc because of the formation of negative hydrostatic pressures.

Experimental occlusal interferences. Part II. Masseteric EMG responses to an intercuspal interference.

Science.gov (United States)

Christensen, L V; Rassouli, N M

1995-07-01

In 12 subjects, a rigid unilateral intercuspal interference (minimum mean height of 0.24 mm) was placed on either the right or left mandibular second premolar and first molar (sagittal physiological equilibrium point of the hemimandibular dental arch). During brisk and forceful clenching on the interference, bipolar surface electromyograms were obtained from the right and left masseter muscles. On the side opposite the interference, myoelectric clenching activity was significantly reduced. Correlation analyses showed that the interference elicited a non-linear (complex) co-ordination of the amplitude, but not the duration, of bilateral masseteric clenching activity, i.e. frequently there was significant motor facilitation on the side of the interference, and significant motor inhibition on the side opposite the interference. Theoretical considerations predicted that brief clenching on the interference would easily lead to frontal plane rotatory motions of the mandible which, indeed, occurred clinically.

IETS and quantum interference

DEFF Research Database (Denmark)

Jørgensen, Jacob Lykkebo; Gagliardi, Alessio; Pecchia, Alessandro

2014-01-01

Destructive quantum interference in single molecule electronics is an intriguing phenomenon; however, distinguishing quantum interference effects from generically low transmission is not trivial. In this paper, we discuss how quantum interference effects in the transmission lead to either low...... suppressed when quantum interference effects dominate. That is, we expand the understanding of propensity rules in inelastic electron tunneling spectroscopy to molecules with destructive quantum interference....

Codebook-based interference alignment for uplink MIMO interference channels

KAUST Repository

Lee, Hyun Ho; Park, Kihong; Ko, Youngchai; Alouini, Mohamed-Slim

2014-01-01

In this paper, we propose a codebook-based interference alignment (IA) scheme in the constant multiple-input multipleoutput (MIMO) interference channel especially for the uplink scenario. In our proposed scheme, we assume cooperation among base

Adaptive Memory: Is Survival Processing Special?

Science.gov (United States)

Nairne, James S.; Pandeirada, Josefa N. S.

2008-01-01

Do the operating characteristics of memory continue to bear the imprints of ancestral selection pressures? Previous work in our laboratory has shown that human memory may be specially tuned to retain information processed in terms of its survival relevance. A few seconds of survival processing in an incidental learning context can produce recall…

PRACTICING FIELD HOCKEY SKILLS ALONG THE CONTEXTUAL INTERFERENCE CONTINUUM: A COMPARISON OF FIVE PRACTICE SCHEDULES

Directory of Open Access Journals (Sweden)

Jadeera Phaik Geok Cheong

2012-06-01

Full Text Available To overcome the weakness of the contextual interference (CI effect within applied settings, Brady, 2008 recommended that the amount of interference be manipulated. This study investigated the effect of five practice schedules on the learning of three field hockey skills. Fifty-five pre-university students performed a total of 90 trials for each skill under blocked, mixed or random practice orders. Results showed a significant time effect with all five practice conditions leading to improvements in acquisition and learning of the skills. No significant differences were found between the groups. The findings of the present study did not support the CI effect and suggest that either blocked, mixed, or random practice schedules can be used effectively when structuring practice for beginners

"Testing during Study Insulates against the Buildup of Proactive Interference": Correction

Science.gov (United States)

Szpunar, Karl K.; McDermott, Kathleen B.; Roedigger, Henry L., III

2009-01-01

Reports an error in "Testing during study insulates against the buildup of proactive interference" by Karl K. Szpunar, Kathleen B. McDermott and Henry L. Roediger III ("Journal of Experimental Psychology: Learning, Memory, and Cognition," 2008[Nov], Vol 34[6], 1392-1399). Incorrect figures were printed due to an error in the…

Iterative Soft Decision Interference Cancellation for DS-CDMA Employing the Distribution of Interference

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Gerstacker WolfgangH

2010-01-01

Full Text Available A well-known receiver strategy for direct-sequence code-division multiple-access (DS-CDMA transmission is iterative soft decision interference cancellation. For calculation of soft estimates used for cancellation, the distribution of residual interference is commonly assumed to be Gaussian. In this paper, we analyze matched filter-based iterative soft decision interference cancellation (MF ISDIC when utilizing an approximation of the actual probability density function (pdf of residual interference. In addition, a hybrid scheme is proposed, which reduces computational complexity by considering the strongest residual interferers according to their pdf while the Gaussian assumption is applied to the weak residual interferers. It turns out that the bit error ratio decreases already noticeably when only a small number of residual interferers is regarded according to their pdf. For the considered DS-CDMA transmission the bit error ratio decreases by 80% for high signal-to-noise ratios when modeling all residual interferers but the strongest three to be Gaussian distributed.

Mitigation of MIMO Co-Channel Interference using robust interference cancellation receiver

DEFF Research Database (Denmark)

Rahman, Muhammad Imadur; De Carvalho, Elisabeth; Prasad, Ramjee

2007-01-01

(STBC) link may become equivalent to an interfering Spatial Multiplexing (SM) link. Using this knowledge and understanding, we propose an interference cancellation receiver robust to different types of MIMO interferers at cell edge for the Downlink (DL) of cellular systems. The receiver systematically...... performs a multiple symbol processing: this is the appropriate processing when the signal of interest or the signal of interferer is correlated across symbols, which is the case for STBC transmission. We evaluated different link combinations in terms of Signal to Interference and Noise Ratio (SINR......) statistics and Bit Error Rate (BER) performance in cellular Orthogonal Frequency Division Multiple Access (OFDMA) systems. We have found that the proposed multiple-symbol linear interference cancellation receiver performs satisfactorily when any kind of single 'logical' stream MIMO scheme is present...

Experimental occlusal interferences. Part IV. Mandibular rotations induced by a pliable interference.

Science.gov (United States)

Christensen, L V; Rassouli, N M

1995-11-01

In 12 subjects, a pliable, yet unbreakable, intercuspal interference (aluminum shim onlay splint; uniform height of 0.25 mm) was placed between either the right or left maxillary and mandibular second premolars and first molars. During brief and forceful biting (dynamic chewing stroke of about 20 kg force) the interference emulated a semisoft food bolus, and at the end of biting (subsequent static clenching stroke of about 20 kg force) it emulated a rigid metal interference. During dynamic/static biting, rotational electrognathography measured maximum frontal and horizontal plane torque of the right and left mandibular condyles. Eleven subjects (92%) showed frontal plane upward rotation (mean of 1.0 degree) of the condyle contralateral to the interference, and one subject (8%) showed frontal plane upward rotation (0.4 degree) of the condyle ipsilateral to the interference. Two subjects (17%) showed no horizontal plane rotation; seven subjects (58%) showed backward rotation (mean of 0.4 degree) of the condyle contralateral to the interference; and three subjects (25%) showed backward rotation (mean of 0.3 degree) of the condyle ipsilateral to the interference. It is suggested that, in the presence of an occlusal interference, mastication may have both short- and long-term detrimental effects.

Experimental statistical signature of many-body quantum interference

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Giordani, Taira; Flamini, Fulvio; Pompili, Matteo; Viggianiello, Niko; Spagnolo, Nicolò; Crespi, Andrea; Osellame, Roberto; Wiebe, Nathan; Walschaers, Mattia; Buchleitner, Andreas; Sciarrino, Fabio

2018-03-01

Multi-particle interference is an essential ingredient for fundamental quantum mechanics phenomena and for quantum information processing to provide a computational advantage, as recently emphasized by boson sampling experiments. Hence, developing a reliable and efficient technique to witness its presence is pivotal in achieving the practical implementation of quantum technologies. Here, we experimentally identify genuine many-body quantum interference via a recent efficient protocol, which exploits statistical signatures at the output of a multimode quantum device. We successfully apply the test to validate three-photon experiments in an integrated photonic circuit, providing an extensive analysis on the resources required to perform it. Moreover, drawing upon established techniques of machine learning, we show how such tools help to identify the—a priori unknown—optimal features to witness these signatures. Our results provide evidence on the efficacy and feasibility of the method, paving the way for its adoption in large-scale implementations.

Neural mechanisms of interference control in working memory: effects of interference expectancy and fluid intelligence.

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Gregory C Burgess

2010-09-01

Full Text Available A critical aspect of executive control is the ability to limit the adverse effects of interference. Previous studies have shown activation of left ventrolateral prefrontal cortex after the onset of interference, suggesting that interference may be resolved in a reactive manner. However, we suggest that interference control may also operate in a proactive manner to prevent effects of interference. The current study investigated the temporal dynamics of interference control by varying two factors - interference expectancy and fluid intelligence (gF - that could influence whether interference control operates proactively versus reactively.A modified version of the recent negatives task was utilized. Interference expectancy was manipulated across task blocks by changing the proportion of recent negative (interference trials versus recent positive (facilitation trials. Furthermore, we explored whether gF affected the tendency to utilize specific interference control mechanisms. When interference expectancy was low, activity in lateral prefrontal cortex replicated prior results showing a reactive control pattern (i.e., interference-sensitivity during probe period. In contrast, when interference expectancy was high, bilateral prefrontal cortex activation was more indicative of proactive control mechanisms (interference-related effects prior to the probe period. Additional results suggested that the proactive control pattern was more evident in high gF individuals, whereas the reactive control pattern was more evident in low gF individuals.The results suggest the presence of two neural mechanisms of interference control, with the differential expression of these mechanisms modulated by both experimental (e.g., expectancy effects and individual difference (e.g., gF factors.

Randomized Controlled Trial Considering Varied Exercises for Reducing Proactive Memory Interference

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Emily Frith

2018-06-01

Full Text Available We evaluated the effects of exercise on proactive memory interference. Study 1 (n = 88 employed a 15-min treadmill walking protocol, while Study 2 (n = 88 included a 15-min bout of progressive maximal exertion treadmill exercise. Each study included four distinct groups, in which groups of 22 participants each were randomly assigned to: (a exercise before memory encoding, (b a control group with no exercise, (c exercise during memory encoding, and (d exercise after memory encoding (i.e., during memory consolidation. We used the Rey Auditory Verbal Learning Test (RAVLT to assess proactive memory interference. In both studies, the group that exercised prior to memory encoding recalled the most words from list B (distractor list of the RAVLT, though group differences were not statistically significant for Study 1 (walking exercise (p = 0.521 or Study 2 (high-intensity exercise (p = 0.068. In this sample of young adults, high intensity exercise prior to memory encoding showed a non-significant tendency to attenuate impairments in recall attributable to proactive memory interference. Thus, future work with larger samples is needed to clarify potential beneficial effects of exercise for reducing proactive memory interference.

Randomized Controlled Trial Considering Varied Exercises for Reducing Proactive Memory Interference.

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Frith, Emily; Sng, Eveleen; Loprinzi, Paul D

2018-06-11

We evaluated the effects of exercise on proactive memory interference. Study 1 ( n = 88) employed a 15-min treadmill walking protocol, while Study 2 ( n = 88) included a 15-min bout of progressive maximal exertion treadmill exercise. Each study included four distinct groups, in which groups of 22 participants each were randomly assigned to: (a) exercise before memory encoding, (b) a control group with no exercise, (c) exercise during memory encoding, and (d) exercise after memory encoding (i.e., during memory consolidation). We used the Rey Auditory Verbal Learning Test (RAVLT) to assess proactive memory interference. In both studies, the group that exercised prior to memory encoding recalled the most words from list B (distractor list) of the RAVLT, though group differences were not statistically significant for Study 1 (walking exercise) ( p = 0.521) or Study 2 (high-intensity exercise) ( p = 0.068). In this sample of young adults, high intensity exercise prior to memory encoding showed a non-significant tendency to attenuate impairments in recall attributable to proactive memory interference. Thus, future work with larger samples is needed to clarify potential beneficial effects of exercise for reducing proactive memory interference.

Drilling Deeper into tooth brushing skills: Is proactive interference an under-recognized factor in oral hygiene behavior change?

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Thavarajah, Rooban; Kumar, Madan; Mohandoss, Anusa Arunachalam; Vernon, Lance T

2015-09-01

Proper tooth brushing is a seemingly simple motor activity that can promote oral health. Applying health theories, such as the Information-Motivation-Behavioral Skills (IMB) model, Motivational Interviewing (MI) and Integrated Health Coaching (IHC), may help optimize tooth brushing technique in those with suboptimal skills. Some motor activities, including tooth brushing, may over time become rote and unconscious actions, such that an existing habit can inhibit new learning, i.e., exert proactive interference on learning the new skill. Proactive interference may impede the acquisition of new tooth brushing skills; thus, in this report, we: (1) Review how the habit of tooth brushing is formed; (2) Postulate how proactive interference could impede the establishment of proper tooth brushing retraining; (3) Discuss the merits of this hypothesis; and (4) Provide guidance for future work in this topic within the context of an approach to behavior change that integrates IMB, MI and IHC methodology.

Advanced Online Survival Analysis Tool for Predictive Modelling in Clinical Data Science.

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Montes-Torres, Julio; Subirats, José Luis; Ribelles, Nuria; Urda, Daniel; Franco, Leonardo; Alba, Emilio; Jerez, José Manuel

2016-01-01

One of the prevailing applications of machine learning is the use of predictive modelling in clinical survival analysis. In this work, we present our view of the current situation of computer tools for survival analysis, stressing the need of transferring the latest results in the field of machine learning to biomedical researchers. We propose a web based software for survival analysis called OSA (Online Survival Analysis), which has been developed as an open access and user friendly option to obtain discrete time, predictive survival models at individual level using machine learning techniques, and to perform standard survival analysis. OSA employs an Artificial Neural Network (ANN) based method to produce the predictive survival models. Additionally, the software can easily generate survival and hazard curves with multiple options to personalise the plots, obtain contingency tables from the uploaded data to perform different tests, and fit a Cox regression model from a number of predictor variables. In the Materials and Methods section, we depict the general architecture of the application and introduce the mathematical background of each of the implemented methods. The study concludes with examples of use showing the results obtained with public datasets.

Atypical performance patterns on Delis-Kaplan Executive Functioning System Color-Word Interference Test: Cognitive switching and learning ability in older adults.

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Berg, Jody-Lynn; Swan, Natasha M; Banks, Sarah J; Miller, Justin B

2016-09-01

Cognitive set shifting requires flexible application of lower level processes. The Delis-Kaplan Executive Functioning System (DKEFS) Color-Word Interference Test (CWIT) is commonly used to clinically assess cognitive set shifting. An atypical pattern of performance has been observed on the CWIT; a subset of individuals perform faster, with equal or fewer errors, on the more difficult inhibition/switching than the inhibition trial. This study seeks to explore the cognitive underpinnings of this atypical pattern. It is hypothesized that atypical patterns on CWIT will be associated with better performance on underlying cognitive measures of attention, working memory, and learning when compared to typical CWIT patterns. Records from 239 clinical referrals (age: M = 68.09 years, SD = 10.62; education: M = 14.87 years, SD = 2.73) seen for a neuropsychological evaluation as part of diagnostic work up in an outpatient dementia and movement disorders clinic were sampled. The standard battery of tests included measures of attention, learning, fluency, executive functioning, and working memory. Analyses of variance (ANOVAs) were conducted to compare the cognitive performance of those with typical versus atypical CWIT patterns. An atypical pattern of performance was confirmed in 23% of our sample. Analyses revealed a significant group difference in acquisition of information on both nonverbal (Brief Visuospatial Memory Test-Revised, BVMT-R total recall), F(1, 213) = 16.61, p < .001, and verbal (Hopkins Verbal Learning Test-Revised, HVLT-R total recall) learning tasks, F(1, 181) = 6.43, p < .01, and semantic fluency (Animal Naming), F(1, 232) = 7.57, p = .006, with the atypical group performing better on each task. Effect sizes were larger for nonverbal (Cohen's d = 0.66) than verbal learning (Cohen's d = 0.47) and semantic fluency (Cohen's d = 0.43). Individuals demonstrating an atypical pattern of performance on the CWIT inhibition/switching trial also demonstrated relative

Neural signatures of second language learning and control.

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Bartolotti, James; Bradley, Kailyn; Hernandez, Arturo E; Marian, Viorica

2017-04-01

Experience with multiple languages has unique effects on cortical structure and information processing. Differences in gray matter density and patterns of cortical activation are observed in lifelong bilinguals compared to monolinguals as a result of their experience managing interference across languages. Monolinguals who acquire a second language later in life begin to encounter the same type of linguistic interference as bilinguals, but with a different pre-existing language architecture. The current study used functional magnetic resonance imaging to explore the beginning stages of second language acquisition and cross-linguistic interference in monolingual adults. We found that after English monolinguals learned novel Spanish vocabulary, English and Spanish auditory words led to distinct patterns of cortical activation, with greater recruitment of posterior parietal regions in response to English words and of left hippocampus in response to Spanish words. In addition, cross-linguistic interference from English influenced processing of newly-learned Spanish words, decreasing hippocampus activity. Results suggest that monolinguals may rely on different memory systems to process a newly-learned second language, and that the second language system is sensitive to native language interference. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reduced susceptibility to interference in the consolidation of motor memory before adolescence.

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Shoshi Dorfberger

2007-02-01

Full Text Available Are children superior to adults in consolidating procedural memory? This notion has been tied to "critical," early life periods of increased brain plasticity. Here, using a motor sequence learning task, we show, in experiment 1, that a the rate of learning during a training session, b the gains accrued, without additional practice, within a 24 hours post-training interval (delayed consolidation gains, and c the long-term retention of these gains, were as effective in 9, 12 and 17-year-olds and comparable to those reported for adults. However, a follow-up experiment showed that the establishment of a memory trace for the trained sequence of movements was significantly more susceptible to interference by a subsequent motor learning experience (practicing a reversed movement sequence in the 17-year-olds compared to the 9 and 12-year-olds. Unlike the 17-year-olds, the younger age-groups showed significant delayed gains even after interference training. Altogether, our results indicate the existence of an effective consolidation phase in motor learning both before and after adolescence, with no childhood advantage in the learning or retention of a motor skill. However, the ability to co-consolidate different, successive motor experiences, demonstrated in both the 9 and 12-year-olds, diminishes after puberty, suggesting that a more selective memory consolidation process takes over from the childhood one. Only the adult consolidation process is gated by a recency effect, and in situations of multiple, clashing, experiences occurring within a short time-interval, adults may less effectively establish in memory experiences superseded by newer ones.

RNA interference: learning gene knock-down from cell physiology

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Provenzano Maurizio

2004-11-01

Full Text Available Summary Over the past decade RNA interference (RNAi has emerged as a natural mechanism for silencing gene expression. This ancient cellular antiviral response can be exploited to allow specific inhibition of the function of any chosen target gene. RNAi is proving to be an invaluable research tool, allowing much more rapid characterization of the function of known genes. More importantly, RNAi technology considerably bolsters functional genomics to aid in the identification of novel genes involved in disease processes. This review briefly describes the molecular principles underlying the biology of RNAi phenomenon and discuss the main technical issues regarding optimization of RNAi experimental design.

RNA interference: learning gene knock-down from cell physiology

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Mocellin, Simone; Provenzano, Maurizio

2004-01-01

Over the past decade RNA interference (RNAi) has emerged as a natural mechanism for silencing gene expression. This ancient cellular antiviral response can be exploited to allow specific inhibition of the function of any chosen target gene. RNAi is proving to be an invaluable research tool, allowing much more rapid characterization of the function of known genes. More importantly, RNAi technology considerably bolsters functional genomics to aid in the identification of novel genes involved in disease processes. This review briefly describes the molecular principles underlying the biology of RNAi phenomenon and discuss the main technical issues regarding optimization of RNAi experimental design. PMID:15555080

Olfactory interference during inhibitory backward pairing in honey bees.

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Matthieu Dacher

Full Text Available Restrained worker honey bees are a valuable model for studying the behavioral and neural bases of olfactory plasticity. The proboscis extension response (PER; the proboscis is the mouthpart of honey bees is released in response to sucrose stimulation. If sucrose stimulation is preceded one or a few times by an odor (forward pairing, the bee will form a memory for this association, and subsequent presentations of the odor alone are sufficient to elicit the PER. However, backward pairing between the two stimuli (sucrose, then odor has not been studied to any great extent in bees, although the vertebrate literature indicates that it elicits a form of inhibitory plasticity.If hungry bees are fed with sucrose, they will release a long lasting PER; however, this PER can be interrupted if an odor is presented 15 seconds (but not 7 or 30 seconds after the sucrose (backward pairing. We refer to this previously unreported process as olfactory interference. Bees receiving this 15 second backward pairing show reduced performance after a subsequent single forward pairing (excitatory conditioning trial. Analysis of the results supported a relationship between olfactory interference and a form of backward pairing-induced inhibitory learning/memory. Injecting the drug cimetidine into the deutocerebrum impaired olfactory interference.Olfactory interference depends on the associative link between odor and PER, rather than between odor and sucrose. Furthermore, pairing an odor with sucrose can lead either to association of this odor to PER or to the inhibition of PER by this odor. Olfactory interference may provide insight into processes that gate how excitatory and inhibitory memories for odor-PER associations are formed.

School is out on noisy reefs: the effect of boat noise on predator learning and survival of juvenile coral reef fishes.

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Ferrari, Maud C O; McCormick, Mark I; Meekan, Mark G; Simpson, Stephen D; Nedelec, Sophie L; Chivers, Douglas P

2018-01-31

Noise produced by anthropogenic activities is increasing in many marine ecosystems. We investigated the effect of playback of boat noise on fish cognition. We focused on noise from small motorboats, since its occurrence can dominate soundscapes in coastal communities, the number of noise-producing vessels is increasing rapidly and their proximity to marine life has the potential to cause deleterious effects. Cognition-or the ability of individuals to learn and remember information-is crucial, given that most species rely on learning to achieve fitness-promoting tasks, such as finding food, choosing mates and recognizing predators. The caveat with cognition is its latent effect: the individual that fails to learn an important piece of information will live normally until the moment where it needs the information to make a fitness-related decision. Such latent effects can easily be overlooked by traditional risk assessment methods. Here, we conducted three experiments to assess the effect of boat noise playbacks on the ability of fish to learn to recognize predation threats, using a common, conserved learning paradigm. We found that fish that were trained to recognize a novel predator while being exposed to 'reef + boat noise' playbacks failed to subsequently respond to the predator, while their 'reef noise' counterparts responded appropriately. We repeated the training, giving the fish three opportunities to learn three common reef predators, and released the fish in the wild. Those trained in the presence of 'reef + boat noise' playbacks survived 40% less than the 'reef noise' controls over our 72 h monitoring period, a performance equal to that of predator-naive fish. Our last experiment indicated that these results were likely due to failed learning, as opposed to stress effects from the sound exposure. Neither playbacks nor real boat noise affected survival in the absence of predator training. Our results indicate that boat noise has the potential to cause

Dependency-dependent interference: NPI interference, agreement attraction, and global pragmatic inferences

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Ming eXiang

2013-10-01

Full Text Available Previous psycholinguistics studies have shown that when forming a long distance dependency in online processing, the parser sometimes accepts a sentence even though the required grammatical constraints are only partially met. A mechanistic account of how such errors arise sheds light on both the underlying linguistic representations involved and the processing mechanisms that put such representations together. In the current study, we contrast the NPI (negative polarity items interference effect, as shown by the acceptance of an ungrammatical sentence like The bills that democratic senators have voted for will ever become law, with the well-known phenomenon of agreement attraction (The key to the cabinets are…. On the surface, these two types of errors look alike and thereby can be explained as being driven by the same source: similarity based memory interference. However, we argue that the linguistic representations involved in NPI licensing are substantially different from those of subject-verb agreement, and therefore the interference effects in each domain potentially arise from distinct sources. In particular, we show that NPI interference at least partially arises from pragmatic inferences. In a self-paced reading study with an acceptability judgment task, we showed NPI interference was modulated by participants’ general pragmatic communicative skills, as quantified by the Autism-Spectrum Quotient (Baron-Cohen 2001, especially in offline tasks. Participants with more autistic traits were actually less prone to the NPI interference effect than those with fewer autistic traits. This result contrasted with agreement attraction conditions, which were not influenced by individual pragmatic skill differences. We also show that different NPI licensors have distinct interference profiles. We discuss two kinds of interference effects for NPI licensing: memory-retrieval based and pragmatically triggered.

The Survival of the Wisest

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Salk, Jonas

1975-01-01

Suggests that humans differ from other living organisms in the ability to exercise learned behavior and the individual will, which may allow people to make the changes in values necessary to survive on this planet. (DW)

Interference control in working memory: comparing groups of children with atypical development.

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Palladino, Paola; Ferrari, Marcella

2013-01-01

The study aimed to test whether working memory deficits in children at risk of Learning Disabilities (LD) and/or attention deficit/hyperactivity disorder (ADHD) can be attributed to deficits in interference control, thereby implicating prefrontal systems. Two groups of children known for showing poor working memory (i.e., children with poor comprehension and children with ADHD) were compared to a group of children with specific reading decoding problems (i.e., having severe problems in phonological rather than working memory) and to a control group. All children were tested with a verbal working memory task. Interference control of irrelevant items was examined by a lexical decision task presented immediately after the final recall in about half the trials, selected at random. The interference control measure was therefore directly related to working memory performance. Results confirmed deficient working memory performance in poor comprehenders and children at risk of ADHD + LD. More interestingly, this working memory deficit was associated with greater activation of irrelevant information than in the control group. Poor decoders showed more efficient interference control, in contrast to poor comprehenders and ADHD + LD children. These results indicated that interfering items were still highly accessible to working memory in children who fail the working memory task. In turn, these findings strengthen and clarify the role of interference control, one of the most critical prefrontal functions, in working memory.

Interference Calculus A General Framework for Interference Management and Network Utility Optimization

CERN Document Server

Schubert, Martin

2012-01-01

This book develops a mathematical framework for modeling and optimizing interference-coupled multiuser systems. At the core of this framework is the concept of general interference functions, which provides a simple means of characterizing interdependencies between users. The entire analysis builds on the two core axioms scale-invariance and monotonicity. The proposed network calculus has its roots in power control theory and wireless communications. It adds theoretical tools for analyzing the typical behavior of interference-coupled networks. In this way it complements existing game-theoretic approaches. The framework should also be viewed in conjunction with optimization theory. There is a fruitful interplay between the theory of interference functions and convex optimization theory. By jointly exploiting the properties of interference functions, it is possible to design algorithms that outperform general-purpose techniques that only exploit convexity. The title “network calculus” refers to the fact tha...

Follow up assessment of very preterm infants at five years of age

NARCIS (Netherlands)

Kleine, Martin de

2005-01-01

Simultaneous with the improved survival of very preterm and low birth weight infants, the awareness increased that not all survive without sequelae. Mild developmental disturbances that interfere with the acquisition of everyday skills and normal learning appeared to be very frequent and were not

Newborn neurons in the olfactory bulb selected for long-term survival through olfactory learning are prematurely suppressed when the olfactory memory is erased.

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Sultan, Sébastien; Rey, Nolwen; Sacquet, Joelle; Mandairon, Nathalie; Didier, Anne

2011-10-19

A role for newborn neurons in olfactory memory has been proposed based on learning-dependent modulation of olfactory bulb neurogenesis in adults. We hypothesized that if newborn neurons support memory, then they should be suppressed by memory erasure. Using an ecological approach in mice, we showed that behaviorally breaking a previously learned odor-reward association prematurely suppressed newborn neurons selected to survive during initial learning. Furthermore, intrabulbar infusions of the caspase pan-inhibitor ZVAD (benzyloxycarbonyl-Val-Ala-Asp) during the behavioral odor-reward extinction prevented newborn neurons death and erasure of the odor-reward association. Newborn neurons thus contribute to the bulbar network plasticity underlying long-term memory.

Between-Trial Forgetting Due to Interference and Time in Motor Adaptation.

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Sungshin Kim

Full Text Available Learning a motor task with temporally spaced presentations or with other tasks intermixed between presentations reduces performance during training, but can enhance retention post training. These two effects are known as the spacing and contextual interference effect, respectively. Here, we aimed at testing a unifying hypothesis of the spacing and contextual interference effects in visuomotor adaptation, according to which forgetting between trials due to either spaced presentations or interference by another task will promote between-trial forgetting, which will depress performance during acquisition, but will promote retention. We first performed an experiment with three visuomotor adaptation conditions: a short inter-trial-interval (ITI condition (SHORT-ITI; a long ITI condition (LONG-ITI; and an alternating condition with two alternated opposite tasks (ALT, with the same single-task ITI as in LONG-ITI. In the SHORT-ITI condition, there was fastest increase in performance during training and largest immediate forgetting in the retention tests. In contrast, in the ALT condition, there was slowest increase in performance during training and little immediate forgetting in the retention tests. Compared to these two conditions, in the LONG-ITI, we found intermediate increase in performance during training and intermediate immediate forgetting. To account for these results, we fitted to the data six possible adaptation models with one or two time scales, and with interference in the fast, or in the slow, or in both time scales. Model comparison confirmed that two time scales and some degree of interferences in either time scale are needed to account for our experimental results. In summary, our results suggest that retention following adaptation is modulated by the degree of between-trial forgetting, which is due to time-based decay in single adaptation task and interferences in multiple adaptation tasks.

The Role of Long-Term Memory in a Test of Visual Working Memory: Proactive Facilitation but No Proactive Interference

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Oberauer, Klaus; Awh, Edward; Sutterer, David W.

2017-01-01

We report 4 experiments examining whether associations in visual working memory are subject to proactive interference from long-term memory (LTM). Following a long-term learning phase in which participants learned the colors of 120 unique objects, a working memory (WM) test was administered in which participants recalled the precise colors of 3…

Sleep can reduce proactive interference.

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Abel, Magdalena; Bäuml, Karl-Heinz T

2014-01-01

Sleep has repeatedly been connected to processes of memory consolidation. While extensive research indeed documents beneficial effects of sleep on memory, little is yet known about the role of sleep for interference effects in episodic memory. Although two prior studies reported sleep to reduce retroactive interference, no sleep effect has previously been found for proactive interference. Here we applied a study format differing from that employed by the prior studies to induce a high degree of proactive interference, and asked participants to encode a single list or two interfering lists of paired associates via pure study cycles. Testing occurred after 12 hours of diurnal wakefulness or nocturnal sleep. Consistent with the prior work, we found sleep in comparison to wake did not affect memory for the single list, but reduced retroactive interference. In addition we found sleep reduced proactive interference, and reduced retroactive and proactive interference to the same extent. The finding is consistent with the view that arising benefits of sleep are caused by the reactivation of memory contents during sleep, which has been suggested to strengthen and stabilise memories. Such stabilisation may make memories less susceptible to competition from interfering memories at test and thus reduce interference effects.

Dark Matter Interference

DEFF Research Database (Denmark)

Del Nobile, Eugenio; Kouvaris, Christoforos; Sannino, Francesco

2012-01-01

We study different patterns of interference in WIMP-nuclei elastic scattering that can accommodate the DAMA and CoGeNT experiments via an isospin violating ratio $f_n/f_p=-0.71$. We study interference between the following pairs of mediators: Z and Z', Z' and Higgs, and two Higgs fields. We show ...

An evaluation of deficits in semantic cueing and proactive and retroactive interference as early features of Alzheimer's disease.

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Crocco, Elizabeth; Curiel, Rosie E; Acevedo, Amarilis; Czaja, Sara J; Loewenstein, David A

2014-09-01

To determine the degree to which susceptibility to different types of semantic interference may reflect the initial manifestations of early Alzheimer's disease (AD) beyond the effects of global memory impairment. Normal elderly (NE) subjects (n = 47), subjects with amnestic mild cognitive impairment (aMCI; n = 34), and subjects with probable AD (n = 40) were evaluated by using a unique cued recall paradigm that allowed for evaluation of both proactive and retroactive interference effects while controlling for global memory impairment (i.e., Loewenstein-Acevedo Scales of Semantic Interference and Learning [LASSI-L] procedure). Controlling for overall memory impairment, aMCI subjects had much greater proactive and retroactive interference effects than NE subjects. LASSI-L indices of learning by using cued recall revealed high levels of sensitivity and specificity, with an overall correct classification rate of 90%. These measures provided better discrimination than traditional neuropsychological measures of memory function. The LASSI-L paradigm is unique and unlike other assessments of memory in that items posed for cued recall are explicitly presented, and semantic interference and cueing effects can be assessed while controlling for initial level of memory impairment. This is a powerful procedure that allows the participant to serve as his or her own control. The high levels of discrimination between subjects with aMCI and normal cognition that exceeded traditional neuropsychological measures makes the LASSI-L worthy of further research in the detection of early AD. Copyright © 2014 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

Interference and Sensitivity Analysis.

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VanderWeele, Tyler J; Tchetgen Tchetgen, Eric J; Halloran, M Elizabeth

2014-11-01

Causal inference with interference is a rapidly growing area. The literature has begun to relax the "no-interference" assumption that the treatment received by one individual does not affect the outcomes of other individuals. In this paper we briefly review the literature on causal inference in the presence of interference when treatments have been randomized. We then consider settings in which causal effects in the presence of interference are not identified, either because randomization alone does not suffice for identification, or because treatment is not randomized and there may be unmeasured confounders of the treatment-outcome relationship. We develop sensitivity analysis techniques for these settings. We describe several sensitivity analysis techniques for the infectiousness effect which, in a vaccine trial, captures the effect of the vaccine of one person on protecting a second person from infection even if the first is infected. We also develop two sensitivity analysis techniques for causal effects in the presence of unmeasured confounding which generalize analogous techniques when interference is absent. These two techniques for unmeasured confounding are compared and contrasted.

Game-theoretic interference coordination approaches for dynamic spectrum access

CERN Document Server

Xu, Yuhua

2016-01-01

Written by experts in the field, this book is based on recent research findings in dynamic spectrum access for cognitive radio networks. It establishes a game-theoretic framework and presents cutting-edge technologies for distributed interference coordination. With game-theoretic formulation and the designed distributed learning algorithms, it provides insights into the interactions between multiple decision-makers and the converging stable states. Researchers, scientists and engineers in the field of cognitive radio networks will benefit from the book, which provides valuable information, useful methods and practical algorithms for use in emerging 5G wireless communication.

Multiple-Antenna Interference Cancellation for WLAN with MAC Interference Avoidance in Open Access Networks

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Alexandr M. Kuzminskiy

2007-10-01

Full Text Available The potential of multiantenna interference cancellation receiver algorithms for increasing the uplink throughput in WLAN systems such as 802.11 is investigated. The medium access control (MAC in such systems is based on carrier sensing multiple-access with collision avoidance (CSMA/CA, which itself is a powerful tool for the mitigation of intrasystem interference. However, due to the spatial dependence of received signal strengths, it is possible for the collision avoidance mechanism to fail, resulting in packet collisions at the receiver and a reduction in system throughput. The CSMA/CA MAC protocol can be complemented in such scenarios by interference cancellation (IC algorithms at the physical (PHY layer. The corresponding gains in throughput are a result of the complex interplay between the PHY and MAC layers. It is shown that semiblind interference cancellation techniques are essential for mitigating the impact of interference bursts, in particular since these are typically asynchronous with respect to the desired signal burst. Semiblind IC algorithms based on second- and higher-order statistics are compared to the conventional no-IC and training-based IC techniques in an open access network (OAN scenario involving home and visiting users. It is found that the semiblind IC algorithms significantly outperform the other techniques due to the bursty and asynchronous nature of the interference caused by the MAC interference avoidance scheme.

Multiple-Antenna Interference Cancellation for WLAN with MAC Interference Avoidance in Open Access Networks

Directory of Open Access Journals (Sweden)

Kuzminskiy Alexandr M

2007-01-01

Full Text Available The potential of multiantenna interference cancellation receiver algorithms for increasing the uplink throughput in WLAN systems such as 802.11 is investigated. The medium access control (MAC in such systems is based on carrier sensing multiple-access with collision avoidance (CSMA/CA, which itself is a powerful tool for the mitigation of intrasystem interference. However, due to the spatial dependence of received signal strengths, it is possible for the collision avoidance mechanism to fail, resulting in packet collisions at the receiver and a reduction in system throughput. The CSMA/CA MAC protocol can be complemented in such scenarios by interference cancellation (IC algorithms at the physical (PHY layer. The corresponding gains in throughput are a result of the complex interplay between the PHY and MAC layers. It is shown that semiblind interference cancellation techniques are essential for mitigating the impact of interference bursts, in particular since these are typically asynchronous with respect to the desired signal burst. Semiblind IC algorithms based on second- and higher-order statistics are compared to the conventional no-IC and training-based IC techniques in an open access network (OAN scenario involving home and visiting users. It is found that the semiblind IC algorithms significantly outperform the other techniques due to the bursty and asynchronous nature of the interference caused by the MAC interference avoidance scheme.

Collision-induced destructive quantum interference

International Nuclear Information System (INIS)

Yang Xihua; Sun Zhenrong; Zhang Shi'an; Ding Liang'en; Wang Zugeng

2005-01-01

We conduct theoretical studies on the collision-induced destructive quantum interference of two-colour two-photon transitions in an open rhomb-type five-level system with a widely separated doublet by the density matrix approach. The effects of the collision-induced decay rates, the ratio of the transition dipole moments and the energy separation of the doublet on the interference are analysed. It is shown that a narrow dip appears in the excitation spectrum due to the collision-induced destructive interference, and that the narrow interference dip still exists even when the collision broadening is comparable to the energy separation of the doublet. The physical origin of the collision-induced destructive quantum interference is analysed in the dressed-atom picture

Learning new meanings for known words: Biphasic effects of prior knowledge

Science.gov (United States)

Fang, Xiaoping; Perfetti, Charles; Stafura, Joseph

2017-01-01

In acquiring word meanings, learners are often confronted by a single word form that is mapped to two or more meanings. For example, long after how to roller-“skate”, one may learn that “skate” is also a kind of fish. Such learning of new meanings for familiar words involves two potentially contrasting processes, relative to new form-new meaning learning: 1) Form-based familiarity may facilitate learning a new meaning, and 2) meaning-based interference may inhibit learning a new meaning. We examined these two processes by having native English speakers learn new, unrelated meanings for familiar (high frequency) and less familiar (low frequency) English words, as well as for unfamiliar (novel or pseudo-) words. Tracking learning with cued-recall tasks at several points during learning revealed a biphasic pattern: higher learning rates and greater learning efficiency for familiar words relative to novel words early in learning and a reversal of this pattern later in learning. Following learning, interference from original meanings for familiar words was detected in a semantic relatedness judgment task. Additionally, lexical access to familiar words with new meanings became faster compared to their exposure controls, but no such effect occurred for less familiar words. Overall, the results suggest a biphasic pattern of facilitating and interfering processes: Familiar word forms facilitate learning earlier, while interference from original meanings becomes more influential later. This biphasic pattern reflects the co-activation of new and old meanings during learning, a process that may play a role in lexicalization of new meanings. PMID:29399593

Linguistic interference occurring in students of Italian philology as a challenge for a lecturer

Directory of Open Access Journals (Sweden)

Małgorzata Karczewska

2011-01-01

Full Text Available Polish students of Italian philology in Poznań study two Romance languages: Italian and French, which on one hand facilitates the process of learning, as many rules of grammar and words are similar in both languages. On the other hand, though, the closeness of two linguistic systems is the source of the interference phenomenon even if none of the languages is a mother tongue. As students of philology are expected to speak perfectly the foreign language studied, all mistakes need to be eliminated. In the present paper we concentrate on mistakes made in Italian due to the interference of French. After a short theoretical introduction on interference we give some examples of errors to illustrate the phenomenon and to show the areas in which errors are particularly numerous. In the third part of the paper we suggest some solutions which are based on observations and conclusions resulting from the professional experience as a lecturer in Italian.

The anterior thalamus is critical for overcoming interference in a context-dependent odor discrimination task.

Science.gov (United States)

Law, L Matthew; Smith, David M

2012-10-01

The anterior thalamus (AT) is anatomically interconnected with the hippocampus and other structures known to be involved in memory, and the AT is involved in many of the same learning and memory functions as the hippocampus. For example, like the hippocampus, the AT is involved in spatial cognition and episodic memory. The hippocampus also has a well-documented role in contextual memory processes, but it is not known whether the AT is similarly involved in contextual memory. In the present study, we assessed the role of the AT in contextual memory processes by temporarily inactivating the AT and training rats on a recently developed context-based olfactory list learning task, which was designed to assess the use of contextual information to resolve interference. Rats were trained on one list of odor discrimination problems, followed by training on a second list in either the same context or a different context. In order to induce interference, some of the odors appeared on both lists with their predictive value reversed. Control rats that learned the two lists in different contexts performed significantly better than rats that learned the two lists in the same context. However, AT lesions completely abolished this contextual learning advantage, a result that is very similar to the effects of hippocampal inactivation. These findings demonstrate that the AT, like the hippocampus, is involved in contextual memory and suggest that the hippocampus and AT are part of a functional circuit involved in contextual memory. PsycINFO Database Record (c) 2012 APA, all rights reserved.

Stroop interference and reverse Stroop interference as potential measures of cognitive ability during exposure to stress

OpenAIRE

景山, 望; 箱田, 裕司; Kageyama, Nozomu; Hakoda, Yuji

2011-01-01

Stroop interference and reverse-Stroop interference are one of the easiest and most powerful effects to demonstrate in a classroom. Therefore, they have been studied not only through basic research in the laboratory but also through applied research in extreme environments. First, we reviewed studies tha investigated Stroop interference and reverse-Stroop interference as hallmark measures of selective at attention and conflict resolution. Second, we reviewed studies that examined the effects ...

New episodic learning interferes with the reconsolidation of autobiographical memories.

Directory of Open Access Journals (Sweden)

Lars Schwabe

Full Text Available It is commonly assumed that, with time, an initially labile memory is transformed into a permanent one via a process of consolidation. Yet, recent evidence indicates that memories can return to a fragile state again when reactivated, requiring a period of reconsolidation. In the study described here, we found that participants who memorized a story immediately after they had recalled neutral and emotional experiences from their past were impaired in their memory for the neutral (but not for the emotional experiences one week later. The effect of learning the story depended critically on the preceding reactivation of the autobiographical memories since learning without reactivation had no effect. These results suggest that new learning impedes the reconsolidation of neutral autobiographical memories.

The effects of a single bout of exercise on motor memory interference in the trained and untrained hemisphere

OpenAIRE

Lauber, Benedikt; Franke, Steffen; Taube, Wolfgang; Gollhofer, Albert

2017-01-01

Increasing evidence suggests that cardiovascular exercise has positive effects on motor memory consolidation. In this study, we investigated whether a single session of high-intensity interval training (HIIT) mitigates the effects of practicing an interfering motor task. Furthermore, learning and interference effects were assessed in the actively trained and untrained limb as it is known that unilateral motor learning can cause bilateral adaptations.Subjects performed a ballistic trainin...

Communications in interference limited networks

CERN Document Server

2016-01-01

This book offers means to handle interference as a central problem of operating wireless networks. It investigates centralized and decentralized methods to avoid and handle interference as well as approaches that resolve interference constructively. The latter type of approach tries to solve the joint detection and estimation problem of several data streams that share a common medium. In fact, an exciting insight into the operation of networks is that it may be beneficial, in terms of an overall throughput, to actively create and manage interference. Thus, when handled properly, "mixing" of data in networks becomes a useful tool of operation rather than the nuisance as which it has been treated traditionally. With the development of mobile, robust, ubiquitous, reliable and instantaneous communication being a driving and enabling factor of an information centric economy, the understanding, mitigation and exploitation of interference in networks must be seen as a centrally important task.

The Approximate Capacity Region of the Symmetric $K$-user Gaussian Interference Channel with Strong Interference

KAUST Repository

Chaaban, Anas

2016-03-01

The symmetric K-user interference channel is studied with the goal of characterizing its capacity region in the strong interference regime within a constant gap. The achievable rate region of a scheme combining rate-splitting at the transmitters and interference alignment and successive decoding/computation at the receivers is derived. Next it is shown that this scheme achieves the so-called greedy-max corner points of the capacity region within a constant gap. By combining this result with previous results by Ordentlich et al. on the sum-capacity of the symmetric interference channel, a constant gap characterization of the capacity region for the strong interference regime is obtained. This leads to the first approximate characterization of the capacity region of the symmetric K-user IC. Furthermore, a new scheme that achieves the sum-capacity of the channel in the strong interference regime within a constant gap is also proposed, and the corresponding gap is calculated. The advantage of the new scheme is that it leads to a characterization within a constant gap without leaving an outage set contrary to the scheme by Ordentlich et al..

The Approximate Capacity Region of the Symmetric $K$-user Gaussian Interference Channel with Strong Interference

KAUST Repository

Chaaban, Anas; Sezgin, Aydin

2016-01-01

The symmetric K-user interference channel is studied with the goal of characterizing its capacity region in the strong interference regime within a constant gap. The achievable rate region of a scheme combining rate-splitting at the transmitters and interference alignment and successive decoding/computation at the receivers is derived. Next it is shown that this scheme achieves the so-called greedy-max corner points of the capacity region within a constant gap. By combining this result with previous results by Ordentlich et al. on the sum-capacity of the symmetric interference channel, a constant gap characterization of the capacity region for the strong interference regime is obtained. This leads to the first approximate characterization of the capacity region of the symmetric K-user IC. Furthermore, a new scheme that achieves the sum-capacity of the channel in the strong interference regime within a constant gap is also proposed, and the corresponding gap is calculated. The advantage of the new scheme is that it leads to a characterization within a constant gap without leaving an outage set contrary to the scheme by Ordentlich et al..

Breast cancer data analysis for survivability studies and prediction.

Science.gov (United States)

Shukla, Nagesh; Hagenbuchner, Markus; Win, Khin Than; Yang, Jack

2018-03-01

Breast cancer is the most common cancer affecting females worldwide. Breast cancer survivability prediction is challenging and a complex research task. Existing approaches engage statistical methods or supervised machine learning to assess/predict the survival prospects of patients. The main objectives of this paper is to develop a robust data analytical model which can assist in (i) a better understanding of breast cancer survivability in presence of missing data, (ii) providing better insights into factors associated with patient survivability, and (iii) establishing cohorts of patients that share similar properties. Unsupervised data mining methods viz. the self-organising map (SOM) and density-based spatial clustering of applications with noise (DBSCAN) is used to create patient cohort clusters. These clusters, with associated patterns, were used to train multilayer perceptron (MLP) model for improved patient survivability analysis. A large dataset available from SEER program is used in this study to identify patterns associated with the survivability of breast cancer patients. Information gain was computed for the purpose of variable selection. All of these methods are data-driven and require little (if any) input from users or experts. SOM consolidated patients into cohorts of patients with similar properties. From this, DBSCAN identified and extracted nine cohorts (clusters). It is found that patients in each of the nine clusters have different survivability time. The separation of patients into clusters improved the overall survival prediction accuracy based on MLP and revealed intricate conditions that affect the accuracy of a prediction. A new, entirely data driven approach based on unsupervised learning methods improves understanding and helps identify patterns associated with the survivability of patient. The results of the analysis can be used to segment the historical patient data into clusters or subsets, which share common variable values and

Adaptive memory: the comparative value of survival processing.

Science.gov (United States)

Nairne, James S; Pandeirada, Josefa N S; Thompson, Sarah R

2008-02-01

We recently proposed that human memory systems are "tuned" to remember information that is processed for survival, perhaps as a result of fitness advantages accrued in the ancestral past. This proposal was supported by experiments in which participants showed superior memory when words were rated for survival relevance, at least relative to when words received other forms of deep processing. The current experiments tested the mettle of survival memory by pitting survival processing against conditions that are universally accepted as producing excellent retention, including conditions in which participants rated words for imagery, pleasantness, and self-reference; participants also generated words, studied words with the intention of learning them, or rated words for relevance to a contextually rich (but non-survival-related) scenario. Survival processing yielded the best retention, which suggests that it may be one of the best encoding procedures yet discovered in the memory field.

Interference-exact radiative transfer equation

DEFF Research Database (Denmark)

Partanen, Mikko; Haÿrynen, Teppo; Oksanen, Jani

2017-01-01

Maxwell's equations with stochastic or quantum optical source terms accounting for the quantum nature of light. We show that both the nonlocal wave and local particle features associated with interference and emission of propagating fields in stratified geometries can be fully captured by local damping...... and scattering coefficients derived from the recently introduced quantized fluctuational electrodynamics (QFED) framework. In addition to describing the nonlocal optical interference processes as local directionally resolved effects, this allows reformulating the well known and widely used radiative transfer...... equation (RTE) as a physically transparent interference-exact model that extends the useful range of computationally efficient and quantum optically accurate interference-aware optical models from simple structures to full optical devices....

CyberSurfiver: Affective considerations of `surviving\\' online learning ...

African Journals Online (AJOL)

online learning environment. The basis for the study was a master\\'s course presented entirely online for a period of six weeks. The style of the internationally acclaimed reality television game show, Survivor#, was used as a guiding format for developing the course. The game was played in cyberspace; and as the learning

Laser self-mixing interference fibre sensor

International Nuclear Information System (INIS)

Zhu Jun; Zhao Yan; Jin Guofan

2008-01-01

Fibre sensors exhibit a number of advantages over other sensors such as high sensitivity, electric insulation, corrosion resistance, interference rejection and so on. And laser self-mixing interference can accurately detect the phase difference of feedback light. In this paper, a novel laser self-mixing interference fibre sensor that combines the advantages of fibre sensors with those of laser self-mixing interference is presented. Experimental configurations are set up to study the relationship between laser power output and phase of laser feedback light when the fibre trembles or when the fibre is stretched or pressed. The theoretical analysis of pressure sensors based on laser self-mixing interference is indicated to accord with the experimental results. (classical areas of phenomenology)

47 CFR 27.1221 - Interference protection.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Interference protection. 27.1221 Section 27... Technical Standards § 27.1221 Interference protection. (a) Interference protection will be afforded to BRS... height benchmark (hbm). (c) Protection for Receiving Antennas not Exceeding the Height Benchmark. Absent...

Binaural Interference: Quo Vadis?

Science.gov (United States)

Jerger, James; Silman, Shlomo; Silverman, Carol; Emmer, Michele

2017-04-01

The reality of the phenomenon of binaural interference with speech recognition has been debated for two decades. Research has taken one of two avenues; group studies or case reports. In group studies, a sample of the elderly population is tested on speech recognition under three conditions; binaural, monaural right and monaural left. The aim is to determine the percent of the sample in which the expected outcome (binaural score-better-than-either-monaural score) is reversed (i.e., one of the monaural scores is better than the binaural score). This outcome has been commonly used to define binaural interference. The object of group studies is to answer the "how many" question, what is the prevalence of binaural interference in the sample. In case reports the binaural interference conclusion suggested by the speech recognition tests is not accepted until it has been corroborated by other independent diagnostic audiological measures. The aim is to attempt to determine the basis for the findings, to answer the "why" question. This article is at once tutorial, editorial and a case report. We argue that it is time to accept the reality of the phenomenon of binaural interference, to eschew group statistical approaches in search of an answer to the "how many" question, and to focus on individual case reports in search of an answer to the "why" question. American Academy of Audiology.

An accumulator model of semantic interference

NARCIS (Netherlands)

van Maanen, Leendert; van Rijn, Hedderik

To explain latency effects in picture-word interference tasks, cognitive models need to account for both interference and stimulus onset asynchrony (SOA) effects. As opposed to most models of picture-word interference, which model the time course during the task in a ballistic manner, the RACE model

(Sub-)Optimality of Treating Interference as Noise in the Cellular Uplink With Weak Interference

KAUST Repository

Gherekhloo, Soheil; Chaaban, Anas; Di, Chen; Sezgin, Aydin

2015-01-01

Despite the simplicity of the scheme of treating interference as noise (TIN), it was shown to be sum-capacity optimal in the Gaussian interference channel (IC) with very-weak (noisy) interference. In this paper, the two-user IC is altered by introducing an additional transmitter that wants to communicate with one of the receivers of the IC. The resulting network thus consists of a point-to-point channel interfering with a multiple access channel (MAC) and is denoted by PIMAC. The sum-capacity of the PIMAC is studied with main focus on the optimality of TIN. It turns out that TIN in its naive variant, where all transmitters are active and both receivers use TIN for decoding, is not the best choice for the PIMAC. In fact, a scheme that combines both time division multiple access and TIN (TDMA-TIN) strictly outperforms the naive-TIN scheme. Furthermore, it is shown that in some regimes, TDMA-TIN achieves the sum-capacity for the deterministic PIMAC and the sum-capacity within a constant gap for the Gaussian PIMAC. In addition, it is shown that, even for very-weak interference, there are some regimes where a combination of interference alignment with power control and TIN at the receiver side outperforms TDMA-TIN. As a consequence, on the one hand, TIN in a cellular uplink is approximately optimal in certain regimes. On the other hand, those regimes cannot be simply described by the strength of interference.

(Sub-)Optimality of Treating Interference as Noise in the Cellular Uplink With Weak Interference

KAUST Repository

Gherekhloo, Soheil

2015-11-09

Despite the simplicity of the scheme of treating interference as noise (TIN), it was shown to be sum-capacity optimal in the Gaussian interference channel (IC) with very-weak (noisy) interference. In this paper, the two-user IC is altered by introducing an additional transmitter that wants to communicate with one of the receivers of the IC. The resulting network thus consists of a point-to-point channel interfering with a multiple access channel (MAC) and is denoted by PIMAC. The sum-capacity of the PIMAC is studied with main focus on the optimality of TIN. It turns out that TIN in its naive variant, where all transmitters are active and both receivers use TIN for decoding, is not the best choice for the PIMAC. In fact, a scheme that combines both time division multiple access and TIN (TDMA-TIN) strictly outperforms the naive-TIN scheme. Furthermore, it is shown that in some regimes, TDMA-TIN achieves the sum-capacity for the deterministic PIMAC and the sum-capacity within a constant gap for the Gaussian PIMAC. In addition, it is shown that, even for very-weak interference, there are some regimes where a combination of interference alignment with power control and TIN at the receiver side outperforms TDMA-TIN. As a consequence, on the one hand, TIN in a cellular uplink is approximately optimal in certain regimes. On the other hand, those regimes cannot be simply described by the strength of interference.

A Role of Protein Degradation in Memory Consolidation after Initial Learning and Extinction Learning in the Honeybee ("Apis mellifera")

Science.gov (United States)

Felsenberg, Johannes; Dombrowski, Vincent; Eisenhardt, Dorothea

2012-01-01

Protein degradation is known to affect memory formation after extinction learning. We demonstrate here that an inhibitor of protein degradation, MG132, interferes with memory formation after extinction learning in a classical appetitive conditioning paradigm. In addition, we find an enhancement of memory formation when the same inhibitor is…

Increased actin polymerization and stabilization interferes with neuronal function and survival in the AMPKγ mutant Loechrig.

Directory of Open Access Journals (Sweden)

Mandy Cook

Full Text Available loechrig (loe mutant flies are characterized by progressive neuronal degeneration, behavioral deficits, and early death. The mutation is due to a P-element insertion in the gene for the γ-subunit of the trimeric AMP-activated protein kinase (AMPK complex, whereby the insertion affects only one of several alternative transcripts encoding a unique neuronal isoform. AMPK is a cellular energy sensor that regulates a plethora of signaling pathways, including cholesterol and isoprenoid synthesis via its downstream target hydroxy-methylglutaryl (HMG-CoA reductase. We recently showed that loe interferes with isoprenoid synthesis and increases the prenylation and thereby activation of RhoA. During development, RhoA plays an important role in neuronal outgrowth by activating a signaling cascade that regulates actin dynamics. Here we show that the effect of loe/AMPKγ on RhoA prenylation leads to a hyperactivation of this signaling pathway, causing increased phosphorylation of the actin depolymerizating factor cofilin and accumulation of filamentous actin. Furthermore, our results show that the resulting cytoskeletal changes in loe interfere with neuronal growth and disrupt axonal integrity. Surprisingly, these phenotypes were enhanced by expressing the Slingshot (SSH phosphatase, which during development promotes actin depolymerization by dephosphorylating cofilin. However, our studies suggest that in the adult SSH promotes actin polymerization, supporting in vitro studies using human SSH1 that suggested that SSH can also stabilize and bundle filamentous actin. Together with the observed increase in SSH levels in the loe mutant, our experiments suggest that in mature neurons SSH may function as a stabilization factor for filamentous actin instead of promoting actin depolymerization.

Forgetting in immediate serial recall: decay, temporal distinctiveness, or interference?

Science.gov (United States)

Oberauer, Klaus; Lewandowsky, Stephan

2008-07-01

Three hypotheses of forgetting from immediate memory were tested: time-based decay, decreasing temporal distinctiveness, and interference. The hypotheses were represented by 3 models of serial recall: the primacy model, the SIMPLE (scale-independent memory, perception, and learning) model, and the SOB (serial order in a box) model, respectively. The models were fit to 2 experiments investigating the effect of filled delays between items at encoding or at recall. Short delays between items, filled with articulatory suppression, led to massive impairment of memory relative to a no-delay baseline. Extending the delays had little additional effect, suggesting that the passage of time alone does not cause forgetting. Adding a choice reaction task in the delay periods to block attention-based rehearsal did not change these results. The interference-based SOB fit the data best; the primacy model overpredicted the effect of lengthening delays, and SIMPLE was unable to explain the effect of delays at encoding. The authors conclude that purely temporal views of forgetting are inadequate. Copyright (c) 2008 APA, all rights reserved.

Using Interference to Block RFID Tags

DEFF Research Database (Denmark)

Krigslund, Rasmus; Popovski, Petar; Pedersen, Gert Frølund

We propose a novel method to block RFID tags from responding, using intentional interference. We focus on the experimental evaluation, where we impose interference on the download and uplink, respectively. The results are positive, where modulated CCI shows most effective to block a tag.......We propose a novel method to block RFID tags from responding, using intentional interference. We focus on the experimental evaluation, where we impose interference on the download and uplink, respectively. The results are positive, where modulated CCI shows most effective to block a tag....

Interleaved Practice in Multi-Dimensional Learning Tasks: Which Dimension Should We Interleave?

Science.gov (United States)

Rau, Martina A.; Aleven, Vincent; Rummel, Nikol

2013-01-01

Research shows that multiple representations can enhance student learning. Many curricula use multiple representations across multiple task types. The temporal sequence of representations and task types is likely to impact student learning. Research on contextual interference shows that interleaving learning tasks leads to better learning results…

Optical interference with noncoherent states

International Nuclear Information System (INIS)

Sagi, Yoav; Firstenberg, Ofer; Fisher, Amnon; Ron, Amiram

2003-01-01

We examine a typical two-source optical interference apparatus consisting of two cavities, a beam splitter, and two detectors. We show that field-field interference occurs even when the cavities are not initially in coherent states but rather in other nonclassical states. However, we find that the visibility of the second-order interference, that is, the expectation values of the detectors' readings, changes from 100%, when the cavities are prepared in coherent states, to zero visibility when they are initially in single Fock states. We calculate the fourth-order interference, and for the latter case find that it corresponds to a case where the currents oscillate with 100% visibility, but with a random phase for every experiment. Finally, we suggest an experimental realization of the apparatus with nonclassical sources

Interference management using direct sequence spread spectrum ...

African Journals Online (AJOL)

Interference management using direct sequence spread spectrum (DSSS) technique ... Journal of Fundamental and Applied Sciences ... Keywords: DSSS, LTE network; Wi-Fi network; SINR; interference management and interference power.

Shutting Down Sensorimotor Interferences after Stroke: A Proof-of-Principle SMR Neurofeedback Study

Science.gov (United States)

Reichert, Johanna L.; Kober, Silvia E.; Schweiger, Daniela; Grieshofer, Peter; Neuper, Christa; Wood, Guilherme

2016-01-01

Introduction: Neurofeedback training aims at learning self-regulation of brain activity underlying cognitive, emotional or physiological functions. Despite of promising investigations on neurofeedback as a tool for cognitive rehabilitation in neurological diseases, such as after stroke, there is still a lack of research on feasibility and efficiency of neurofeedback in this field. Methods: The present study aimed at investigating behavioral and electrophysiological effects of 10 sessions of sensorimotor rhythm (SMR) neurofeedback in a 74-years-old stroke patient (UG20). Based on previous results in healthy young participants, we hypothesized that SMR neurofeedback leads to a decrease in sensorimotor interferences and improved stimulus processing, reflected by changes in event-related potentials (ERPs) and electrophysiological coherence. To assess whether UG20 benefited from the training as much as healthy persons of a similar age, a healthy control group of N = 10 elderly persons was trained as well. Before and after neurofeedback training, participants took part in a multichannel electroencephalography measurement conducted during a non-verbal and a verbal learning task. Results: Both UG20 and the healthy controls were able to regulate their SMR activity during neurofeedback training. Moreover, in a non-verbal learning task, changes in ERPs and coherence were observed after training: UG20 showed a better performance in the non-verbal learning task and a higher P3 amplitude after training than before, and coherence between central and parietal electrodes decreased after training. The control group also showed a behavioral improvement in the non-verbal learning task and tendencies for higher P3 amplitudes and decreased central-parietal coherence after training. Single-case analyses indicated that the changes observed in UG20 were not smaller than the changes in healthy controls. Conclusion: Neurofeedback can be successfully applied in a stroke patient and in healthy

Shutting down sensorimotor interferences after stroke: A proof-of-principle SMR neurofeedback study

Directory of Open Access Journals (Sweden)

Johanna Louise Reichert

2016-07-01

Full Text Available Introduction: Neurofeedback training aims at learning self-regulation of brain activity underlying cognitive, emotional or physiological functions. Despite of promising investigations on neurofeedback as a tool for cognitive rehabilitation in neurological diseases, such as after stroke, there is still a lack of research on feasibility and efficiency of neurofeedback in this field. Methods: The present study aimed at investigating behavioral and electrophysiological effects of 10 sessions of sensorimotor rhythm (SMR neurofeedback in a 74-year-old stroke patient (UG20. Based on previous results in healthy young participants, we hypothesized that SMR neurofeedback leads to a decrease in sensorimotor interferences and improved stimulus processing, reflected by changes in event-related potentials and electrophysiological coherence. To assess whether UG20 benefited from the training as much as healthy persons of a similar age, a healthy control group of N = 10 elderly persons was trained as well. Before and after neurofeedback training, participants took part in a multichannel EEG measurement conducted during a nonverbal and a verbal learning task. Results: Both UG20 and the healthy controls were able to regulate their SMR activity during neurofeedback training. Moreover, in a nonverbal learning task, changes in event-related potentials and coherence were observed after training: UG20 showed a better performance in the nonverbal learning task and a higher P3 amplitude after training than before, and coherence between central and parietal electrodes decreased after training. The control group also showed a behavioral improvement in the nonverbal learning task and tendencies for higher P3 amplitudes and decreased central-parietal coherence after training. Single-case analyses indicated that the changes observed in UG20 were not smaller than the changes in healthy controls. Conclusions: Neurofeedback can be successfully applied in a stroke patient and in

Dying scenarios improve recall as much as survival scenarios.

Science.gov (United States)

Burns, Daniel J; Hart, Joshua; Kramer, Melanie E

2014-01-01

Merely contemplating one's death improves retention for entirely unrelated material learned subsequently. This "dying to remember" effect seems conceptually related to the survival processing effect, whereby processing items for their relevance to being stranded in the grasslands leads to recall superior to that of other deep processing control conditions. The present experiments directly compared survival processing scenarios with "death processing" scenarios. Results showed that when the survival and dying scenarios are closely matched on key dimensions, and possible congruency effects are controlled, the dying and survival scenarios produced equivalently high recall levels. We conclude that the available evidence (cf. Bell, Roer, & Buchner, 2013; Klein, 2012), while not definitive, is consistent with the possibility of overlapping mechanisms.

Quantum eraser for three-slit interference

Indian Academy of Sciences (India)

Naveed Ahmad Shah

2017-11-09

Nov 9, 2017 ... Abstract. It is well known that in a two-slit interference experiment, if the information, on which of the two paths the particle followed, is stored in a quantum path detector, the interference is destroyed. However, in a set-up where this path information is 'erased', the interference can reappear. Such a set-up is ...

When it hurts (and helps to try: the role of effort in language learning.

Directory of Open Access Journals (Sweden)

Amy S Finn

Full Text Available Compared to children, adults are bad at learning language. This is counterintuitive; adults outperform children on most measures of cognition, especially those that involve effort (which continue to mature into early adulthood. The present study asks whether these mature effortful abilities interfere with language learning in adults and further, whether interference occurs equally for aspects of language that adults are good (word-segmentation versus bad (grammar at learning. Learners were exposed to an artificial language comprised of statistically defined words that belong to phonologically defined categories (grammar. Exposure occurred under passive or effortful conditions. Passive learners were told to listen while effortful learners were instructed to try to 1 learn the words, 2 learn the categories, or 3 learn the category-order. Effortful learners showed an advantage for learning words while passive learners showed an advantage for learning the categories. Effort can therefore hurt the learning of categories.

When It Hurts (and Helps) to Try: The Role of Effort in Language Learning

Science.gov (United States)

Finn, Amy S.; Lee, Taraz; Kraus, Allison; Hudson Kam, Carla L.

2014-01-01

Compared to children, adults are bad at learning language. This is counterintuitive; adults outperform children on most measures of cognition, especially those that involve effort (which continue to mature into early adulthood). The present study asks whether these mature effortful abilities interfere with language learning in adults and further, whether interference occurs equally for aspects of language that adults are good (word-segmentation) versus bad (grammar) at learning. Learners were exposed to an artificial language comprised of statistically defined words that belong to phonologically defined categories (grammar). Exposure occurred under passive or effortful conditions. Passive learners were told to listen while effortful learners were instructed to try to 1) learn the words, 2) learn the categories, or 3) learn the category-order. Effortful learners showed an advantage for learning words while passive learners showed an advantage for learning the categories. Effort can therefore hurt the learning of categories. PMID:25047901

Electromagnetic interference: a radiant future!

NARCIS (Netherlands)

Leferink, Frank Bernardus Johannes

2015-01-01

Although Electromagnetic Interference and Electromagnetic Compatibility are well established domains, the introduction of new technologies results in new challenges. Changes in both measurement techniques, and technological trends resulting in new types of interference are described. These are the

Contextual interference effects on the acquisition of skill and strength of the bench press.

Science.gov (United States)

Naimo, Marshall A; Zourdos, Michael C; Wilson, Jacob M; Kim, Jeong-Su; Ward, Emery G; Eccles, David W; Panton, Lynn B

2013-06-01

The purpose of this study was to investigate contextual interference effects on skill acquisition and strength gains during the learning of the bench press movement. Twenty-four healthy, college-aged males and females were stratified to control, high contextual interference (HCI), and low contextual interference (LCI) groups. Treatment groups were provided with written and visual instruction on proper bench press form and practiced the bench press and dart throwing for four weeks. Within each session, LCI performed all bench press sets before undertaking dart-throws. HCI undertook dart-throws immediately following each set of bench press. Control only did testing. Measurements, including one repetition maximum (1RM), checklist scores based on video recordings of participants' 1RM's, and dart-throw test scores were taken at pre-test, 1 week, 2 week, post-test, and retention test. Results were consistent with the basic premise of the contextual interference effect. LCI had significant improvements in percent 1RM and checklist scores during training, but were mostly absent after training (post-test and retention test). HCI had significant improvements in percent 1RM and checklist scores both during and after training. Thus, HCI may augment strength and movement skill on the bench press since proper technique is an important component of resistance exercise movements. Copyright © 2013 Elsevier B.V. All rights reserved.

An Interference-Aware Traffic-Priority-Based Link Scheduling Algorithm for Interference Mitigation in Multiple Wireless Body Area Networks

Directory of Open Access Journals (Sweden)

Thien T. T. Le

2016-12-01

Full Text Available Currently, wireless body area networks (WBANs are effectively used for health monitoring services. However, in cases where WBANs are densely deployed, interference among WBANs can cause serious degradation of network performance and reliability. Inter-WBAN interference can be reduced by scheduling the communication links of interfering WBANs. In this paper, we propose an interference-aware traffic-priority-based link scheduling (ITLS algorithm to overcome inter-WBAN interference in densely deployed WBANs. First, we model a network with multiple WBANs as an interference graph where node-level interference and traffic priority are taken into account. Second, we formulate link scheduling for multiple WBANs as an optimization model where the objective is to maximize the throughput of the entire network while ensuring the traffic priority of sensor nodes. Finally, we propose the ITLS algorithm for multiple WBANs on the basis of the optimization model. High spatial reuse is also achieved in the proposed ITLS algorithm. The proposed ITLS achieves high spatial reuse while considering traffic priority, packet length, and the number of interfered sensor nodes. Our simulation results show that the proposed ITLS significantly increases spatial reuse and network throughput with lower delay by mitigating inter-WBAN interference.

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

Quantum Interference and Coherence Theory and Experiments

CERN Document Server

Ficek, Zbigniew; Rhodes, William T; Asakura, Toshimitsu; Brenner, Karl-Heinz; Hänsch, Theodor W; Kamiya, Takeshi; Krausz, Ferenc; Monemar, Bo; Venghaus, Herbert; Weber, Horst; Weinfurter, Harald

2005-01-01

For the first time, this book assembles in a single volume accounts of many phenomena involving quantum interference in optical fields and atomic systems. It provides detailed theoretical treatments and experimental analyses of such phenomena as quantum erasure, quantum lithography, multi-atom entanglement, quantum beats, control of decoherence, phase control of quantum interference, coherent population trapping, electromagnetically induced transparency and absorption, lasing without inversion, subluminal and superluminal light propagation, storage of photons, quantum interference in phase space, interference and diffraction of cold atoms, and interference between Bose-Einstein condensates. This book fills a gap in the literature and will be useful to both experimentalists and theoreticians.

Rank-Constrained Beamforming for MIMO Cognitive Interference Channel

Directory of Open Access Journals (Sweden)

Duoying Zhang

2016-01-01

Full Text Available This paper considers the spectrum sharing multiple-input multiple-output (MIMO cognitive interference channel, in which multiple primary users (PUs coexist with multiple secondary users (SUs. Interference alignment (IA approach is introduced that guarantees that secondary users access the licensed spectrum without causing harmful interference to the PUs. A rank-constrained beamforming design is proposed where the rank of the interferences and the desired signals is concerned. The standard interferences metric for the primary link, that is, interference temperature, is investigated and redesigned. The work provides a further improvement that optimizes the dimension of the interferences in the cognitive interference channel, instead of the power of the interference leakage. Due to the nonconvexity of the rank, the developed optimization problems are further approximated as convex form and are solved via choosing the transmitter precoder and receiver subspace iteratively. Numerical results show that the proposed designs can improve the achievable degree of freedom (DoF of the primary links and provide the considerable sum rate for both secondary and primary transmissions under the rank constraints.

When increasing distraction helps learning: Distractor number and content interact in their effects on memory.

Science.gov (United States)

Nussenbaum, Kate; Amso, Dima; Markant, Julie

2017-11-01

Previous work has demonstrated that increasing the number of distractors in a search array can reduce interference from distractor content during target processing. However, it is unclear how this reduced interference influences learning of target information. Here, we investigated how varying the amount and content of distraction present in a learning environment affects visual search and subsequent memory for target items. In two experiments, we demonstrate that the number and content of competing distractors interact in their influence on target selection and memory. Specifically, while increasing the number of distractors present in a search array made target detection more effortful, it did not impair learning and memory for target content. Instead, when the distractors contained category information that conflicted with the target, increasing the number of distractors from one to three actually benefitted learning and memory. These data suggest that increasing numbers of distractors may reduce interference from conflicting conceptual information during encoding.

Interference in immunoassay

International Nuclear Information System (INIS)

Chapman, R.S.

1998-01-01

Interfering factors are evident in both limited reagent (radioimmunoassay) and excess reagent (immunometric assay) technologies and should be suspected whenever there is a discrepancy between analytical results and clinical findings in the investigation of particular diseases. The overall effect of interference in immunoassay is analytical bias in result, either positive or negative of variable magnitude. The interference maybe caused by a wide spectrum of factors from poor sample collection and handling to physiological factors e.g. lipaemia, heparin treatment, binding protein abnormalities, autoimmunity and drug treatments. The range of interfering factors is extensive and difficult to discuss effectively in a short review

Diverse microbial species survive high ammonia concentrations

Science.gov (United States)

Kelly, Laura C.; Cockell, Charles S.; Summers, Stephen

2012-04-01

Planetary protection regulations are in place to control the contamination of planets and moons with terrestrial micro-organisms in order to avoid jeopardizing future scientific investigations relating to the search for life. One environmental chemical factor of relevance in extraterrestrial environments, specifically in the moons of the outer solar system, is ammonia (NH3). Ammonia is known to be highly toxic to micro-organisms and may disrupt proton motive force, interfere with cellular redox reactions or cause an increase of cell pH. To test the survival potential of terrestrial micro-organisms exposed to such cold, ammonia-rich environments, and to judge whether current planetary protection regulations are sufficient, soil samples were exposed to concentrations of NH3 from 5 to 35% (v/v) at -80°C and room temperature for periods up to 11 months. Following exposure to 35% NH3, diverse spore-forming taxa survived, including representatives of the Firmicutes (Bacillus, Sporosarcina, Viridibacillus, Paenibacillus, Staphylococcus and Brevibacillus) and Actinobacteria (Streptomyces). Non-spore forming organisms also survived, including Proteobacteria (Pseudomonas) and Actinobacteria (Arthrobacter) that are known to have environmentally resistant resting states. Clostridium spp. were isolated from the exposed soil under anaerobic culture. High NH3 was shown to cause a reduction in viability of spores over time, but spore morphology was not visibly altered. In addition to its implications for planetary protection, these data show that a large number of bacteria, potentially including spore-forming pathogens, but also environmentally resistant non-spore-formers, can survive high ammonia concentrations.

Episodic Memory Encoding Interferes with Reward Learning and Decreases Striatal Prediction Errors

Science.gov (United States)

Braun, Erin Kendall; Daw, Nathaniel D.

2014-01-01

Learning is essential for adaptive decision making. The striatum and its dopaminergic inputs are known to support incremental reward-based learning, while the hippocampus is known to support encoding of single events (episodic memory). Although traditionally studied separately, in even simple experiences, these two types of learning are likely to co-occur and may interact. Here we sought to understand the nature of this interaction by examining how incremental reward learning is related to concurrent episodic memory encoding. During the experiment, human participants made choices between two options (colored squares), each associated with a drifting probability of reward, with the goal of earning as much money as possible. Incidental, trial-unique object pictures, unrelated to the choice, were overlaid on each option. The next day, participants were given a surprise memory test for these pictures. We found that better episodic memory was related to a decreased influence of recent reward experience on choice, both within and across participants. fMRI analyses further revealed that during learning the canonical striatal reward prediction error signal was significantly weaker when episodic memory was stronger. This decrease in reward prediction error signals in the striatum was associated with enhanced functional connectivity between the hippocampus and striatum at the time of choice. Our results suggest a mechanism by which memory encoding may compete for striatal processing and provide insight into how interactions between different forms of learning guide reward-based decision making. PMID:25378157

The Role of Organizational Humanistic Social Support in Decreasing the Interference of Work Problems on Employees’ Family Conflict

Directory of Open Access Journals (Sweden)

Azman Ismail

2013-02-01

Full Text Available Despite an increased interest in humanistic touch in global organizational support, the nature of helping processes rendered by supervisor and coworkers is still vague. The study was performed to examine the relationship between organizational humanistic social support and work interference with family conflict using 100 usable questionnaires gathered from academic staff in a Malaysian public institution of higher learning in Borneo. The findings of SmartPLS path model indicated that humanistic touch in term of supervisory support significantly correlated with work interference with family conflict. Similarly, humanistic touch of coworker support significantly correlated with work interference with family conflict. This result shows that the readiness of supervisors and coworkers to amply offer material and moral support in performing task have reduced the intrusion of work problems in employees’ family affairs and enriched their skills to decrease family conflicts. In addition, discussion, implications and conclusion are elaborated.

Episodic memory encoding interferes with reward learning and decreases striatal prediction errors.

Science.gov (United States)

Wimmer, G Elliott; Braun, Erin Kendall; Daw, Nathaniel D; Shohamy, Daphna

2014-11-05

Learning is essential for adaptive decision making. The striatum and its dopaminergic inputs are known to support incremental reward-based learning, while the hippocampus is known to support encoding of single events (episodic memory). Although traditionally studied separately, in even simple experiences, these two types of learning are likely to co-occur and may interact. Here we sought to understand the nature of this interaction by examining how incremental reward learning is related to concurrent episodic memory encoding. During the experiment, human participants made choices between two options (colored squares), each associated with a drifting probability of reward, with the goal of earning as much money as possible. Incidental, trial-unique object pictures, unrelated to the choice, were overlaid on each option. The next day, participants were given a surprise memory test for these pictures. We found that better episodic memory was related to a decreased influence of recent reward experience on choice, both within and across participants. fMRI analyses further revealed that during learning the canonical striatal reward prediction error signal was significantly weaker when episodic memory was stronger. This decrease in reward prediction error signals in the striatum was associated with enhanced functional connectivity between the hippocampus and striatum at the time of choice. Our results suggest a mechanism by which memory encoding may compete for striatal processing and provide insight into how interactions between different forms of learning guide reward-based decision making. Copyright © 2014 the authors 0270-6474/14/3414901-12$15.00/0.

Exogenous sample contamination. Sources and interference.

Science.gov (United States)

Cornes, Michael P

2016-12-01

Clinical laboratory medicine is involved in the vast majority of patient care pathways. It has been estimated that pathology results inform 60-70% of critical patient care decisions. The primary goal of the laboratory is to produce precise and accurate results which reflect the true situation in vivo. It is not surprising that interference occurs in laboratory analysis given the complexity of some of the assays used to perform them. Interference is defined as "the effect of a substance upon any step in the determination of the concentration or catalytic activity of the metabolite". Exogenous interferences are defined as those that derive from outside of the body and are therefore not normally found in a specimen and can cause either a positive or negative bias in analytical results. Interferences in analysis can come from various sources and can be classified as endogenous or exogenous. Exogenous substances could be introduced at any point in the sample journey. The laboratory must take responsibility for the quality of results produced. It has a responsibility to have processes in place to identify and minimise the occurrence and effect contamination and interference. To do this well the laboratory needs to work with clinicians and manufacturers. Failure to identify an erroneous result could have an impact on patient care, patient safety and also on hospital budgets. However it is not always easy to recognise interferences. This review summarises the types and sources of exogenous interference and some steps to minimise the impact they have. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Investigation of Interference Models for RFID Systems

Directory of Open Access Journals (Sweden)

Linchao Zhang

2016-02-01

Full Text Available The reader-to-reader collision in an RFID system is a challenging problem for communications technology. In order to model the interference between RFID readers, different interference models have been proposed, mainly based on two approaches: single and additive interference. The former only considers the interference from one reader within a certain range, whereas the latter takes into account the sum of all of the simultaneous interferences in order to emulate a more realistic behavior. Although the difference between the two approaches has been theoretically analyzed in previous research, their effects on the estimated performance of the reader-to-reader anti-collision protocols have not yet been investigated. In this paper, the influence of the interference model on the anti-collision protocols is studied by simulating a representative state-of-the-art protocol. The results presented in this paper highlight that the use of additive models, although more computationally intensive, is mandatory to improve the performance of anti-collision protocols.

Distributed interference alignment iterative algorithms in symmetric wireless network

Directory of Open Access Journals (Sweden)

YANG Jingwen

2015-02-01

Full Text Available Interference alignment is a novel interference alignment way,which is widely noted all of the world.Interference alignment overlaps interference in the same signal space at receiving terminal by precoding so as to thoroughly eliminate the influence of interference impacted on expected signals,thus making the desire user achieve the maximum degree of freedom.In this paper we research three typical algorithms for realizing interference alignment,including minimizing the leakage interference,maximizing Signal to Interference plus Noise Ratio (SINR and minimizing mean square error(MSE.All of these algorithms utilize the reciprocity of wireless network,and iterate the precoders between original network and the reverse network so as to achieve interference alignment.We use the uplink transmit rate to analyze the performance of these three algorithms.Numerical simulation results show the advantages of these algorithms.which is the foundation for the further study in the future.The feasibility and future of interference alignment are also discussed at last.

Biological effects of an aqueous extract of Salix alba on the survival of Escherichia coli AB1157 cultures submitted to the action of stannous chloride

Directory of Open Access Journals (Sweden)

RAPHAEL S S SOUZA

2009-01-01

Full Text Available Stannous chloride (SnC12 is used in nuclear medicine as a reducing agent to obtain technetium-99m-radiopharmaceuticals. It have been reported that natural products might reduce the genotoxic and cytotoxic effects related to SnC12. This work evaluated the biological effects of an aqueous extract of Salix alba on the survival of Escherichia coli (E. coli AB1157 (wild type cultures submitted to the action of SnC12. E. coli AB1157 cultures (exponential growth phase were collected by centrifugation, washed and resuspended in 0.9%NaCl. Samples were incubated in water bath shaker with: (a SnC12 (25mg/ml, (bSalix alba extract(11.6mg/ml and (cSnC12(25mg/ml + Salix alba extract (11.6mg/ml. Incubation with 0.9% NaCl was also carried out (control. At 60 min intervals, aliquots were withdrawn, diluted, spread onto Petri dishes with solid LB medium and incubated overnight. The colonies formed were counted and the survival fractions calculated. The extract was not able to protect the E. coli cultures against the lesive action of SnC12. The extract also did not interfere with the survival of the cultures. It suggested that the substances present in the Salix alba aqueous extract did not interfere strongly with cellular metabolism and did not alter the survival fractions of E. coli AB 1157. It is speculated that this extract cannot interfere with the generation of free radicals, the possible main agent responsible for SnC12 lesive action.

Teacher Learning by Script

Science.gov (United States)

Reeves, Jenelle

2010-01-01

Scripted instruction (SI) programs, which direct teachers to teach, even to talk, from a standardized written script, are roundly criticized for inhibiting teacher creativity and teacher learning. In fact, such programs utilize scripting for exactly that reason: to reduce teacher interference with (and presumed weakening of) the prescribed…

Cognitive interference management in heterogeneous networks

CERN Document Server

Marabissi, Dania

2015-01-01

This brief investigates the role of interference management in Heterogeneous Networks (Het Nets), focusing on cognitive approaches and the use of beamforming. Key concepts of Het Nets are introduced and different deployment strategies are examined, such as sharing the same frequency band of the macro cells or using new high frequency bands. Particular attention is devoted to co-channel deployment and to the problem of interference management, addressing various strategies that can be adopted to handle the interference between the cells. In addition, the brief explores cognitive small cells which are able to avoid or limit interference by using suitable beamforming and resource allocation schemes. The suggested solutions are supported by numerical results in terms of performance evaluations and comparisons.

Structural constraints on organisational and interorganisational learning

DEFF Research Database (Denmark)

Hjalager, Anne-Mette

This paper examines the rates of mortality, survival and entrepreneurship in the Danish restaurant sector, and it demonstrates a considerable turbulence in the sector over the period 1980-1993. Opportunities for organizational learning is enhanced by size as well as age. However surprisingly......, survival is not clearly related to the managerial capacity. Neither is affiliation with other restaurants is an important factor for survival. The study indicates that learning in restaurants is decisively embedded in processes and technologies rather than in relation between human beings....

Laser reflector with an interference coating

International Nuclear Information System (INIS)

Vol'pyan, O D; Semenov, A A; Yakovlev, P P

1998-01-01

An analysis was made of the reflectivity of interference coatings intended for the use in optical pumping of solid-state lasers. Ruby and Nd 3+ :YAG lasers were used as models in comparative pumping efficiency measurements, carried out employing reflectors with interference and silver coatings. Estimates of the service life of reflectors with interference coatings were obtained. The power of a thermo-optical lens was reduced by the use of such coatings in cw lasers. (laser system components)

The Effects of Age on Short-Term Memory Loss due to Proactive Interference

OpenAIRE

Alisha Berkauzer

2011-01-01

This project focused on how proactive interference affects the short-term memory of people based on their age. The goal was to find the prime age for learning information and storing it in one's memory. Seven people from ages fifteen to forty were tested individually, using a set color pattern, in order to see how well each individual could remember the different color patterns as difficulty of the pattern increased. The obtained data was fitted by the polynomial regression. The “fitted...

Interference Phenomenon with Mobile Displays

Science.gov (United States)

Trantham, Kenneth

2015-01-01

A simple experiment is presented in which the spacing and geometric pattern of pixels in mobile displays is measured. The technique is based on optical constructive interference. While the experiment is another opportunity to demonstrate wave interference from a grating-like structure, this can also be used to demonstrate concepts of solid state…

Neural mechanisms of proactive interference-resolution.

Science.gov (United States)

Nee, Derek Evan; Jonides, John; Berman, Marc G

2007-12-01

The ability to mitigate interference from information that was previously relevant, but is no longer relevant, is central to successful cognition. Several studies have implicated left ventrolateral prefrontal cortex (VLPFC) as a region tied to this ability, but it is unclear whether this result generalizes across different tasks. In addition, it has been suggested that left anterior prefrontal cortex (APFC) also plays a role in proactive interference-resolution although support for this claim has been limited. The present study used event-related functional magnetic resonance imaging (fMRI) to investigate the role of these regions in resolving proactive-interference across two different tasks performed on the same subjects. Results indicate that both left VLPFC and left APFC are involved in the resolution of proactive interference across tasks. However, different functional networks related to each region suggest dissociable roles for the two regions. Additionally, regions of the posterior cingulate gyrus demonstrated unique involvement in facilitation when short- and long-term memory converged. This pattern of results serves to further specify models of proactive interference-resolution.

Impairments in Learning Due to Motivational Conflict: Situation Really Matters

Science.gov (United States)

Brassler, Nina K.; Grund, Axel; Hilckmann, Kristina; Fries, Stefan

2016-01-01

Although many theories mention distractions by conflicting alternatives as a problem for self-regulation, motivational conflicts are rarely considered when explaining impairments in learning. In two studies, we investigate the assumption of motivational interference theory that students show different amounts of impairments in learning depending…

Human response to interference with TV picture quality

Energy Technology Data Exchange (ETDEWEB)

Janischewskyj, W.; Harvey, E.B.

1980-10-01

Corona on transmission line conductors and spark gaps on loose or defective transmission line hardware can give rise to visual interference to television interference. The extent to which the interference is a concern (i.e., annoying) depends on the intensity of the interference as well as the strength of the television signal and can best be expressed as a function of the signal-to-noise ratio (SNR), the decibel difference between the wanted signal and the unwanted noise (interference). The study documented in this report has assessed, through subjective testing involving over 500 subjects, the interference level, as a function of SNR, of three different sources of interference: wet-weather conductor corona, a large spark gap (5 mm), and a small spark gap (0.8 mm). The results of the study should be particularly useful to the utility industry in assessing the environmental impact of high-voltage transmission lines.

Carnitine protects the nematode Caenorhabditis elegans from glucose-induced reduction of survival depending on the nuclear hormone receptor DAF-12

International Nuclear Information System (INIS)

Deusing, Dorothé Jenni; Beyrer, Melanie; Fitzenberger, Elena; Wenzel, Uwe

2015-01-01

Besides its function in transport of fatty acids into mitochondria in order to provide substrates for β-oxidation, carnitine has been shown to affect also glucose metabolism and to inhibit several mechanisms associated with diabetic complications. In the present study we used the mev-1 mutant of the nematode Caenorhabditis elegans fed on a high glucose concentration in liquid media as a diabetes model and tested the effects of carnitine supplementation on their survival under heat-stress. Carnitine at 100 μM completely prevented the survival reduction that was caused by the application of 10 mM glucose. RNA-interference for sir-2.1, a candidate genes mediating the effects of carnitine revealed no contribution of the sirtuin for the rescue of survival. Under daf-12 RNAi rescue of survival by carnitine was abolished. RNA-interference for γ-butyrobetaine hydroxylase 2, encoding the key enzyme for carnitine biosynthesis did neither increase glucose toxicity nor prevent the rescue of survival by carnitine, suggesting that the effects of carnitine supplementation on carnitine levels were significant. Finally, it was demonstrated that neither the amount of lysosomes nor the proteasomal activity were increased by carnitine, excluding that protein degradation pathways, such as autophagy or proteasomal degradation, are involved in the protective carnitine effects. In conclusion, carnitine supplementation prevents the reduction of survival caused by glucose in C. elegans in dependence on a nuclear hormone receptor which displays high homologies to the vertebrate peroxisomal proliferator activated receptors. - Highlights: • Carnitine protects from glucose-induced reduction of stress-resistance. • Carnitine acts via the PPAR homolog DAF-12 on glucose toxicity. • Carnitine protects from glucose toxicity independent of protein degradation

Carnitine protects the nematode Caenorhabditis elegans from glucose-induced reduction of survival depending on the nuclear hormone receptor DAF-12

Energy Technology Data Exchange (ETDEWEB)

Deusing, Dorothé Jenni, E-mail: Dorothe.J.Deusing@ernaehrung.uni-giessen.de; Beyrer, Melanie, E-mail: m.beyrer@web.de; Fitzenberger, Elena, E-mail: Elena.Fitzenberger@ernaehrung.uni-giessen.de; Wenzel, Uwe, E-mail: uwe.wenzel@ernaehrung.uni-giessen.de

2015-05-08

Besides its function in transport of fatty acids into mitochondria in order to provide substrates for β-oxidation, carnitine has been shown to affect also glucose metabolism and to inhibit several mechanisms associated with diabetic complications. In the present study we used the mev-1 mutant of the nematode Caenorhabditis elegans fed on a high glucose concentration in liquid media as a diabetes model and tested the effects of carnitine supplementation on their survival under heat-stress. Carnitine at 100 μM completely prevented the survival reduction that was caused by the application of 10 mM glucose. RNA-interference for sir-2.1, a candidate genes mediating the effects of carnitine revealed no contribution of the sirtuin for the rescue of survival. Under daf-12 RNAi rescue of survival by carnitine was abolished. RNA-interference for γ-butyrobetaine hydroxylase 2, encoding the key enzyme for carnitine biosynthesis did neither increase glucose toxicity nor prevent the rescue of survival by carnitine, suggesting that the effects of carnitine supplementation on carnitine levels were significant. Finally, it was demonstrated that neither the amount of lysosomes nor the proteasomal activity were increased by carnitine, excluding that protein degradation pathways, such as autophagy or proteasomal degradation, are involved in the protective carnitine effects. In conclusion, carnitine supplementation prevents the reduction of survival caused by glucose in C. elegans in dependence on a nuclear hormone receptor which displays high homologies to the vertebrate peroxisomal proliferator activated receptors. - Highlights: • Carnitine protects from glucose-induced reduction of stress-resistance. • Carnitine acts via the PPAR homolog DAF-12 on glucose toxicity. • Carnitine protects from glucose toxicity independent of protein degradation.

Down-regulation of Fusarium oxysporum endogenous genes by Host-Delivered RNA interference enhances disease resistance

Directory of Open Access Journals (Sweden)

Zongli eHu

2015-01-01

Full Text Available Fusarium oxysporum is a devastating pathogen causing extensive yield losses in a variety of crops and development of sustainable, environmentally friendly methods to improve crop resistance is crucial. We have used Host-Derived RNA interference (HD-RNAi technology to partially silence three different genes (FOW2, FRP1 and OPR in the hemi-biotrophic fungus Fusarium oxysporum f. sp. conglutinans. Expression of double stranded RNA molecules targeting fungal pathogen genes was achieved in a number of transgenic Arabidopsis lines. F. oxysporum infecting the transgenic lines displayed substantially reduced mRNA levels on all three targeted genes, with an average of 75%, 83% and 72% reduction for FOW2, FRP1 and OPR respectively. The silencing of pathogen genes had a clear positive effect on the ability of the transgenic lines to fight infection. All transgenic lines displayed enhanced resistance to F. oxysporum with delayed disease symptom development, especially FRP1 and OPR lines. Survival rates after fungal infection were higher in the transgenic lines compared to control wild type plants which consistently showed survival rates of 10%, with FOW2 lines showing 25% survival; FRP1 lines 30-50% survival and FOW2 between 45-70% survival. The down-regulation effect was specific for the targeted genes without unintended effects in related genes. In addition to producing resistant crops, HD-RNAi can provide a useful tool to rapidly screen candidate fungal pathogenicity genes without the need to produce fungal knockout mutants.

Down-regulation of Fusarium oxysporum endogenous genes by Host-Delivered RNA interference enhances disease resistance

Science.gov (United States)

Hu, Zongli; Parekh, Urvi; Maruta, Natsumi; Trusov, Yuri; Botella, Jimmy

2015-01-01

Fusarium oxysporum is a devastating pathogen causing extensive yield losses in a variety of crops and development of sustainable, environmentally friendly methods to improve crop resistance is crucial. We have used Host-Derived RNA interference (HD-RNAi) technology to partially silence three different genes (FOW2, FRP1 and OPR) in the hemi-biotrophic fungus Fusarium oxysporum f. sp. conglutinans. Expression of double stranded RNA molecules targeting fungal pathogen genes was achieved in a number of transgenic Arabidopsis lines. F. oxysporum infecting the transgenic lines displayed substantially reduced mRNA levels on all three targeted genes, with an average of 75%, 83% and 72% reduction for FOW2, FRP1 and OPR respectively. The silencing of pathogen genes had a clear positive effect on the ability of the transgenic lines to fight infection. All transgenic lines displayed enhanced resistance to F. oxysporum with delayed disease symptom development, especially FRP1 and OPR lines. Survival rates after fungal infection were higher in the transgenic lines compared to control wild type plants which consistently showed survival rates of 10%, with FOW2 lines showing 25% survival; FRP1 lines 30-50% survival and FOW2 between 45-70% survival. The down-regulation effect was specific for the targeted genes without unintended effects in related genes. In addition to producing resistant crops, HD-RNAi can provide a useful tool to rapidly screen candidate fungal pathogenicity genes without the need to produce fungal knockout mutants.

Carbon nanostructure composite for electromagnetic interference

Indian Academy of Sciences (India)

2015-05-30

based composite materials for electromagnetic interference (EMI) shielding. With more and more electronic gadgets being used at different frequencies, there is a need for shielding them from one another to avoid interference.

Understanding quantum interference in general nonlocality

International Nuclear Information System (INIS)

Wang Haijun

2011-01-01

In this paper we attempt to give a new understanding of quantum double-slit interference of fermions in the framework of general nonlocality (GN) [J. Math. Phys. 49, 033513 (2008)] by studying the self-(inter)action of matter wave. From the metric of the GN, we derive a special formalism to interpret the interference contrast when the self-action is perturbative. According to the formalism, the characteristic of interference pattern is in agreement with experiment qualitatively. As examples, we apply the formalism to the cases governed by Schroedinger current and Dirac current, respectively, both of which are relevant to topology. The gap between these two cases corresponds to the fermion magnetic moment, which is possible to test in the near future. In addition, a general interference formalism for both perturbative and nonperturbative self-actions is presented. By analyzing the general formalism we predict that in the nonperturbative limit there is no interference at all. And by comparison with the special formalism of Schroedinger current, the coupling strength of self-action in the limit is found to be ∞. In the perturbative case, the interference from self-action turns out to be the same as that from the standard approach of quantum theory. Then comparing the corresponding coefficients quantitatively we conclude that the coupling strength of self-action in this case falls in the interval [0, 1].

Interference and problem size effect in multiplication fact solving: Individual differences in brain activations and arithmetic performance.

Science.gov (United States)

De Visscher, Alice; Vogel, Stephan E; Reishofer, Gernot; Hassler, Eva; Koschutnig, Karl; De Smedt, Bert; Grabner, Roland H

2018-05-15

In the development of math ability, a large variability of performance in solving simple arithmetic problems is observed and has not found a compelling explanation yet. One robust effect in simple multiplication facts is the problem size effect, indicating better performance for small problems compared to large ones. Recently, behavioral studies brought to light another effect in multiplication facts, the interference effect. That is, high interfering problems (receiving more proactive interference from previously learned problems) are more difficult to retrieve than low interfering problems (in terms of physical feature overlap, namely the digits, De Visscher and Noël, 2014). At the behavioral level, the sensitivity to the interference effect is shown to explain individual differences in the performance of solving multiplications in children as well as in adults. The aim of the present study was to investigate the individual differences in multiplication ability in relation to the neural interference effect and the neural problem size effect. To that end, we used a paradigm developed by De Visscher, Berens, et al. (2015) that contrasts the interference effect and the problem size effect in a multiplication verification task, during functional magnetic resonance imaging (fMRI) acquisition. Forty-two healthy adults, who showed high variability in an arithmetic fluency test, participated in our fMRI study. In order to control for the general reasoning level, the IQ was taken into account in the individual differences analyses. Our findings revealed a neural interference effect linked to individual differences in multiplication in the left inferior frontal gyrus, while controlling for the IQ. This interference effect in the left inferior frontal gyrus showed a negative relation with individual differences in arithmetic fluency, indicating a higher interference effect for low performers compared to high performers. This region is suggested in the literature to be

Psychosocial and Adaptive Deficits Associated with Learning Disability Subtypes

Science.gov (United States)

Backenson, Erica M.; Holland, Sara C.; Kubas, Hanna A.; Fitzer, Kim R.; Wilcox, Gabrielle; Carmichael, Jessica A.; Fraccaro, Rebecca L.; Smith, Amanda D.; Macoun, Sarah J.; Harrison, Gina L.; Hale, James B.

2015-01-01

Children with specific learning disabilities (SLD) have deficits in the basic psychological processes that interfere with learning and academic achievement, and for some SLD subtypes, these deficits can also lead to emotional and/or behavior problems. This study examined psychosocial functioning in 123 students, aged 6 to 11, who underwent…

Interference impacts working memory in mild cognitive impairment

Directory of Open Access Journals (Sweden)

Sara Aurtenetxe

2016-10-01

Full Text Available Mild cognitive impairment (MCI is considered a transitional stage between healthy aging and dementia, specifically Alzheimer’s disease (AD. The most common cognitive impairment of MCI includes episodic memory loss and difficulties in working memory (WM. Interference can deplete WM, and an optimal WM performance requires an effective control of attentional resources between the memoranda and the incoming stimuli. Difficulties in handling interference lead to forgetting. However, the interplay between interference and WM in MCI is not well understood and needs further investigation. The current study investigated the effect of interference during a WM task in 20 MCIs and 20 healthy elder volunteers. Participants performed a delayed match-to-sample paradigm which consisted in two interference conditions, distraction and interruption, and one control condition without any interference. Results evidenced a disproportionate impact of interference on the WM performance of MCIs, mainly in the presence of interruption. These findings demonstrate that interference, and more precisely interruption, is an important proxy for memory-related deficits in MCI. Thus the current findings reveal novel evidence regarding the causes of WM forgetting in MCI patients, associated with difficulties in the mechanisms of attentional control.

Output Interference in Recognition Memory

Science.gov (United States)

Criss, Amy H.; Malmberg, Kenneth J.; Shiffrin, Richard M.

2011-01-01

Dennis and Humphreys (2001) proposed that interference in recognition memory arises solely from the prior contexts of the test word: Interference does not arise from memory traces of other words (from events prior to the study list or on the study list, and regardless of similarity to the test item). We evaluate this model using output…

Does learning performance in horses relate to fearfulness, baseline stress hormone, and social rank?

DEFF Research Database (Denmark)

Christensen, Janne Winther; Ahrendt, Line Peerstrup; Lintrup, Randi

2012-01-01

The ability of horses to learn and remember new tasks is fundamentally important for their use by humans. Fearfulness may, however, interfere with learning, because stimuli in the environment can overshadow signals from the rider or handler. In addition, prolonged high levels of stress hormones c...... to behavioural responses in a standardised fear test. Learning performance in the home environment, however, appears unrelated to fearfulness, social rank and baseline FCM levels.......The ability of horses to learn and remember new tasks is fundamentally important for their use by humans. Fearfulness may, however, interfere with learning, because stimuli in the environment can overshadow signals from the rider or handler. In addition, prolonged high levels of stress hormones can...... affect neurons within the hippocampus; a brain region central to learning and memory. In a series of experiments, we aimed to investigate the link between performance in two learning tests, the baseline level of stress hormones, measured as faecal cortisol metabolites (FCM), fearfulness, and social rank...

WEED INTERFERENCE IN EGGPLANT CROPS

Directory of Open Access Journals (Sweden)

LUIZ JUNIOR PEREIRA MARQUES

2017-01-01

Full Text Available Uncontrolled weed growth interferes with the growth eggplants and crop yields. To control weeds, the main weed species must be identified in crop growing areas and during weed control periods, as weed species might vary in relation to management practices. Therefore, this study aimed to identify the main weed species and determine the periods of weed interference in the eggplant cultivar Nápoli when grown under certain cultural practices, including plant staking and sprout thinning. The experiment was carried out in 2014 using a randomized complete block design, with 3 replications. The treatments consisted of 11 periods of (1 increasing weed control and (2 increasing coexistence of eggplant with weeds from the first day of transplanting (0-14, 0-28, 0-42, 0-56, 0-70, 0-84, 0-98, 0-112, 0-126, 0-140, and up do day 154. Eggplant staking and sprout thinning were performed 42 days after transplanting (DAT. Weed identification and crop yield assessments were performed to determine the Period Before Interference (PBI, Total Period of Interference Prevention (TPIP, and the Critical Period of Interference Prevention (CPIP. The major weeds found in the eggplant cultivar Nápoli were Eleusine indica, Portulaca oleracea, and Cyperus rotundus. Coexistence between the weed community and the eggplant throughout the entire crop production cycle reduced eggplant fruit yield by 78%. The PBI was 29 DAT and the TPIP was 48 DAT, resulting in 19 days of CPIP.

Analysing Self Interference Cancellation in Full Duplex Radios

DEFF Research Database (Denmark)

Mahmood, Nurul Huda; Shafique Ansari, Imran; Berardinelli, Gilberto

2016-01-01

Full duplex communication promises a theoretical $100\\%$ throughput gain by doubling the number of simultaneous transmissions. Such compelling gains are conditioned on perfect cancellation of the self interference power resulting from simultaneous transmission and reception. Generally, self...... interference power is modelled as a noise-like constant level interference floor. However, experimental validations have shown that the self interference power is in practice a random variable depending on a number of factors such as the surrounding wireless environment and the degree of interference...... cancellation. In this study, we derive an analytical model for the residual self interference power, and demonstrate various applications of the derived model in analysing the performance of a Full Duplex radio. In general, full duplex communication is found to provide only modest throughput gains over half...

Visualizing the phenomena of wave interference, phase-shifting and polarization by interactive computer simulations

Science.gov (United States)

Rivera-Ortega, Uriel; Dirckx, Joris

2015-09-01

In this manuscript a computer based simulation is proposed for teaching concepts of interference of light (under the scheme of a Michelson interferometer), phase-shifting and polarization states. The user can change some parameters of the interfering waves, such as their amplitude and phase difference in order to graphically represent the polarization state of a simulated travelling wave. Regarding to the interference simulation, the user is able to change the wavelength and type of the interfering waves by selecting combinations between planar and Gaussian profiles, as well as the optical path difference by translating or tilting one of the two mirrors in the interferometer setup, all of this via a graphical user interface (GUI) designed in MATLAB. A theoretical introduction and simulation results for each phenomenon will be shown. Due to the simulation characteristics, this GUI can be a very good non-formal learning resource.

Detection device for control rod interference

International Nuclear Information System (INIS)

Saito, Noboru.

1984-01-01

Purpose: To enable to detect the mechanical interference or friction between a control rod and a channel box automatically, simply and rapidly. Constitution: A signal from a gate circuit and a signal from a comparison mechanism are inputted into an AND circuit if a control rod has not been displaced by a predetermined distance within a prescribed time Δt after the output of an insertion or withdrawal signal for the control rod, by which a control-rod-interference signal is outputted from the AND circuit. Accordingly, the interference between the control rod and the channel box can be detected automatically, easily and rapidly. Furthermore, by properly adjusting the prescribed time Δt set by the gate circuit, the degree of the interference can also be detected, whereby the safety and the reliability of the reactor can be improved significantly. (Horiuchi, T.)

Interference Coordination for Dense Wireless Networks

DEFF Research Database (Denmark)

Soret, Beatriz; Pedersen, Klaus I.; Jørgensen, Niels T.K.

2015-01-01

and dense deployment in Tokyo are compared. Evolution to DenseNets offers new opportunities for further development of downlink interference cooperation techniques. Various mechanisms in LTE and LTE-Advanced are revisited. Some techniques try to anticipate the future in a proactive way, whereas others......The promise of ubiquitous and super-fast connectivity for the upcoming years will be in large part fulfilled by the addition of base stations and spectral aggregation. The resulting very dense networks (DenseNets) will face a number of technical challenges. Among others, the interference emerges...... as an old acquaintance with new significance. As a matter of fact, the interference conditions and the role of aggressor and victim depend to a large extent on the density and the scenario. To illustrate this, downlink interference statistics for different 3GPP simulation scenarios and a more irregular...

Neurogenesis paradoxically decreases both pattern separation and memory interference

Directory of Open Access Journals (Sweden)

Rory eFinnegan

2015-10-01

Full Text Available The hippocampus has been the focus of memory research for decades. While the functional role of this structure is not fully understood, it is widely recognized as being vital for rapid yet accurate encoding of associative memories. Since the discovery of adult hippocampal neurogenesis in the dentate gyrus by Altman and Das in the 1960's, many theories and models have been put forward to explain the functional role it plays in learning and memory. These models postulate different ways new in which neurons are introduced into the dentate gyrus and their functional importance for learning and memory. Few if any previous models have incorporated the full range of unique properties of young adult-born dentate granule cells and their developmental trajectory. In this paper, we propose a novel computational model of the dentate gyrus that incorporates the developmental trajectory of the adult-born dentate granule cells, including changes in synaptic plasticity, connectivity, excitability and lateral inhibition, using a modified version of the Restricted Boltzmann machine. Our results show superior performance on memory reconstruction tasks for both recent and distally learned items, when the unique characteristics of young dentate granule cells are taken into account. Even though the hyperexcitability of the young neurons generates more overlapping neural codes, reducing pattern separation, the unique properties of the young neurons nonetheless contribute to reducing retroactive and proactive interference, at both short and long time scales. The sparse connectivity is particularly important for generating distinct memory traces for highly overlapping patterns that are learned within the same context.

Neurogenesis-mediated forgetting minimizes proactive interference.

Science.gov (United States)

Epp, Jonathan R; Silva Mera, Rudy; Köhler, Stefan; Josselyn, Sheena A; Frankland, Paul W

2016-02-26

Established memories may interfere with the encoding of new memories, particularly when existing and new memories overlap in content. By manipulating levels of hippocampal neurogenesis, here we show that neurogenesis regulates this form of proactive interference. Increasing hippocampal neurogenesis weakens existing memories and, in doing so, facilitates the encoding of new, conflicting (but not non-conflicting) information in mice. Conversely, decreasing neurogenesis stabilizes existing memories, and impedes the encoding of new, conflicting information. These results suggest that reduced proactive interference is an adaptive benefit of neurogenesis-induced forgetting.

Modeling and analysis of laser active interference optical path

Science.gov (United States)

Shan, Cong-miao; Sun, Hua-yan; Zhao, Yan-zhong; Chen, Jian-biao; Ren, Jian-ying

2017-10-01

By using the geometrical optics and physical optics method, the models of wedge plate interference optical path, Michelson interferometer and Mach Zehnder interferometer thus three different active interference pattern are built. The optical path difference (OPD) launched by different interference patterns, fringe spacing and contrast expression have been derived. The results show that far field interference peak intensity of the wedge plate interference is small, so the detection distance is limited, Michelson interferometer with low contrast affects the performance of detection system, Mach Zehnder interferometer has greater advantages in peak intensity, the variable range of interference fringe spacing and contrast ratio. The results of this study are useful for the theoretical research and practical application of laser active interference detection.

Two-photon quantum interference in a Michelson interferometer

International Nuclear Information System (INIS)

Odate, Satoru; Wang Haibo; Kobayashi, Takayoshi

2005-01-01

We have observed two-photon quantum interference in a Michelson interferometer. For the first time, we experimentally demonstrated two-photon quantum interference patterns, which show the transition from nonsubwavelength interference fringes to the general subwavelength interference. At the same time, a photon bunching effect was also shown by a postselection. The |1, 1> state with a single photon in a mode corresponding to each arm of the interferometer was exclusively postselected by using path difference between two arms

Cognitive Aware Interference Mitigation Scheme for LTE Femtocells

KAUST Repository

Alqerm, Ismail

2015-04-21

Femto-cells deployment in today’s cellular networks came into practice to fulfill the increasing demand for data services. However, interference to other femto and macro-cells users remains an unresolved challenge. In this paper, we propose an interference mitigation scheme to control the cross-tier interference caused by femto-cells to the macro users and the co-tier interference among femtocells. Cognitive radio spectrum sensing capability is utilized to determine the non-occupied channels or the ones that cause minimal interference to the macro users. An awareness based channel allocation scheme is developed with the assistance of the graph-coloring algorithm to assign channels to the femto-cells base stations with power optimization, minimal interference, maximum throughput, and maximum spectrum efficiency. In addition, the scheme exploits negotiation capability to match traffic load and QoS with the channel capacity, and to maintain efficient utilization of the available channels.

Consolidation ou résistance à l'interférence ?Etude de la contribution des états de sommeil aux processus post-apprentissage de consolidation et de résistance à l'interférence lexicale et émotionnelle rétroactive./Consolidation or protection against interference? an investigation of sleep stages contribution in post-learning memory consolidation and protection against lexical and emotional retroactive interference processes.

OpenAIRE

Deliens, Gaétane

2013-01-01

Although a relative consensus exists about the contribution of post-learning sleep in the consolidation of novel information in long term memory, the definition of the respective contributions of sleep stages in memory consolidation processes remains a matter of debates. Scrima (1982) proposed the hypothesis that Slow Waves Sleep (SWS) contributes preventing retroactive interference on recently acquired information, whereas Rapid Eyes Movement sleep (REM) contributes consolidating this inform...

Interference Cancellation Technique Based on Discovery of Spreading Codes of Interference Signals and Maximum Correlation Detection for DS-CDMA System

Science.gov (United States)

Hettiarachchi, Ranga; Yokoyama, Mitsuo; Uehara, Hideyuki

This paper presents a novel interference cancellation (IC) scheme for both synchronous and asynchronous direct-sequence code-division multiple-access (DS-CDMA) wireless channels. In the DS-CDMA system, the multiple access interference (MAI) and the near-far problem (NFP) are the two factors which reduce the capacity of the system. In this paper, we propose a new algorithm that is able to detect all interference signals as an individual MAI signal by maximum correlation detection. It is based on the discovery of all the unknowing spreading codes of the interference signals. Then, all possible MAI patterns so called replicas are generated as a summation of interference signals. And the true MAI pattern is found by taking correlation between the received signal and the replicas. Moreover, the receiver executes MAI cancellation in a successive manner, removing all interference signals by single-stage. Numerical results will show that the proposed IC strategy, which alleviates the detrimental effect of the MAI and the near-far problem, can significantly improve the system performance. Especially, we can obtain almost the same receiving characteristics as in the absense of interference for asynchrnous system when received powers are equal. Also, the same performances can be seen under any received power state for synchronous system.

Electromagnetic interference in electrical systems of motor vehicles

Science.gov (United States)

Dziubiński, M.; Drozd, A.; Adamiec, M.; Siemionek, E.

2016-09-01

Electronic ignition system affects the electronic equipment of the vehicle by electric and magnetic fields. The measurement of radio electromagnetic interference originating from the ignition system affecting the audiovisual test bench was carried out with a variable speed of the ignition system. The paper presents measurements of radio electromagnetic interference in automobiles. In order to determine the level of electromagnetic interference, the audiovisual test bench was equipped with a set of meters for power consumption and assessment of the level of electromagnetic interference. Measurements of the electromagnetic interference level within the audiovisual system were performed on an experimental test bench consisting of the ignition system, starting system and charging system with an alternator and regulator.

Young's double-slit interference with two-color biphotons.

Science.gov (United States)

Zhang, De-Jian; Wu, Shuang; Li, Hong-Guo; Wang, Hai-Bo; Xiong, Jun; Wang, Kaige

2017-12-12

In classical optics, Young's double-slit experiment with colored coherent light gives rise to individual interference fringes for each light frequency, referring to single-photon interference. However, two-photon double-slit interference has been widely studied only for wavelength-degenerate biphoton, known as subwavelength quantum lithography. In this work, we report double-slit interference experiments with two-color biphoton. Different from the degenerate case, the experimental results depend on the measurement methods. From a two-axis coincidence measurement pattern we can extract complete interference information about two colors. The conceptual model provides an intuitional picture of the in-phase and out-of-phase photon correlations and a complete quantum understanding about the which-path information of two colored photons.

Simultaneous Wireless Information and Power Transfer for MIMO Interference Channel Networks Based on Interference Alignment

Directory of Open Access Journals (Sweden)

Anming Dong

2017-09-01

Full Text Available This paper considers power splitting (PS-based simultaneous wireless information and power transfer (SWIPT for multiple-input multiple-output (MIMO interference channel networks where multiple transceiver pairs share the same frequency spectrum. As the PS model is adopted, an individual receiver splits the received signal into two parts for information decoding (ID and energy harvesting (EH, respectively. Aiming to minimize the total transmit power, transmit precoders, receive filters and PS ratios are jointly designed under a predefined signal-to-interference-plus-noise ratio (SINR and EH constraints. The formulated joint transceiver design and power splitting problem is non-convex and thus difficult to solve directly. In order to effectively obtain its solution, the feasibility conditions of the formulated non-convex problem are first analyzed. Based on the analysis, an iterative algorithm is proposed by alternatively optimizing the transmitters together with the power splitting factors and the receivers based on semidefinite programming (SDP relaxation. Moreover, considering the prohibitive computational cost of the SDP for practical applications, a low-complexity suboptimal scheme is proposed by separately designing interference-suppressing transceivers based on interference alignment (IA and optimizing the transmit power allocation together with splitting factors. The transmit power allocation and receive power splitting problem is then recast as a convex optimization problem and solved efficiently. To further reduce the computational complexity, a low-complexity scheme is proposed by calculating the transmit power allocation and receive PS ratios in closed-form. Simulation results show the effectiveness of the proposed schemes in achieving SWIPT for MIMO interference channel (IC networks.

Adaptive single-antenna transmit selection with interference suppression

KAUST Repository

Radaydeh, Redha Mahmoud Mesleh

2011-10-01

This paper studies the performance of adaptive transmit selection with co-channel interference suppression in multipath fading channels. The adaptive selection algorithms are configured for single-antenna bandwidth-efficient or power-efficient transmission with as low transmit channel estimations as possible. Due to the fact that the number of active co-channel interfering signals and their corresponding powers experience random behavior, the adaptation to channels conditions, assuming uniform buffer and traffic loading, is proposed to be jointly based on the transmit channels instantaneous signal-to-noise ratios (SNRs) and signal-to-interference-plus-noise ratios (SINRs). Two interference cancelation algorithms are considered. The first algorithm assumes that the receiver eliminates the impact of the strongest subset of interferers, whereas the second algorithm suggests random cancelation of interferers to further reduce processing complexity. The impact of outdated ordering of interferers powers on the efficiency of interference cancelation, and the effect of imperfect prediction of transmit channels for desired user adaptation are investigated. Analytical formulations for various performance measures and comparisons between the performance and processing complexity of different adaptation schemes are presented. © 2011 IEEE.

Invasion-Flowback Processes During Hydraulic Fracturing Well Interference

Science.gov (United States)

Kenzhekhanov, Shaken; He, Kai; Xu, Liang; Lord, Paul; Lozano, Martin; Neeves, Keith; Yin, Xiaolong

2017-11-01

Drainage-imbibition cycles that simulate hydraulic fracturing fluid's invasion and flowback during well interference were investigated using NOA81 microfluidic micromodels. Well interference is quite common in unconventional oil and gas fields. It is not unusual for the fracturing fluid injected into a well to be discovered in a nearby well. Normally, the effect of such interference is considered to be negative, as fracturing fluid will be imbibed into the porous rock and block the flow path of hydrocarbons. However, field data show that some interferences are beneficial, and microfluidic experiments presented in this study show that surfactant in the fracturing fluid may be a reason for the observed positive interference. Two fluid drainage-imbibition cycles were conducted in micromodels. The first cycle simulates fracturing of the old well and the second cycle simulates fluid invasion from the new well into the old well's fracture network. The experimental data show that while most such interferences indeed can cause production loss, when the old well's fracturing fluid does not contain surfactant yet the new well's fracturing fluid does, interference can be positive, as the residual water saturation in the porous medium is effectively reduced by surfactants.

A trajectory-based understanding of quantum interference

Energy Technology Data Exchange (ETDEWEB)

Sanz, A S; Miret-Artes, S [Instituto de Fisica Fundamental, Consejo Superior de Investigaciones CientIficas, Serrano 123, 28006 Madrid (Spain)], E-mail: asanz@imaff.cfmac.csic.es, E-mail: s.miret@imaff.cfmac.csic.es

2008-10-31

Interference is one of the most fundamental features which characterizes quantum systems. Here we provide an exhaustive analysis of the interfere dynamics associated with wave-packet superpositions from both the standard quantum-mechanical perspective and the Bohmian one. From this analysis, clear and insightful pictures of the physics involved in these kind of processes are obtained, which are of general validity (i.e., regardless of the type of wave packets considered) in the understanding of more complex cases where interference is crucial (e.g., scattering problems, slit diffraction, quantum control scenarios or, even, multipartite interactions). In particular, we show how problems involving wave-packet interference can be mapped onto problems of wave packets scattered off potential barriers.

Interference in the processing of adjunct control

Directory of Open Access Journals (Sweden)

Dan eParker

2015-09-01

Full Text Available Recent research on the memory operations used in language comprehension has revealed a selective profile of interference effects during memory retrieval. Dependencies such as subject-verb agreement show strong facilitatory interference effects from structurally inappropriate but feature-matching distractors, leading to illusions of grammaticality (Dillon, Mishler, Sloggett, & Phillips, 2013; Pearlmutter, Garnsey, & Bock, 1999; Wagers, Lau, & Phillips, 2009. In contrast, dependencies involving reflexive anaphors are generally immune to interference effects (Dillon et al., 2013; Sturt, 2003; Xiang, Dillon, & Phillips, 2009. This contrast has led to the proposal that all anaphors that are subject to structural constraints are immune to facilitatory interference. Here we use an animacy manipulation to examine whether adjunct control dependencies, which involve an interpreted anaphoric relation between a null subject and its licensor, are also immune to facilitatory interference effects. Our results show reliable facilitatory interference in the processing of adjunct control dependencies, which challenges the generalization that anaphoric dependencies as a class are immune to such effects. To account for the contrast between adjunct control and reflexive dependencies, we suggest that variability within anaphora could reflect either an inherent primacy of animacy cues in retrieval processes, or differential degrees of match between potential licensors and the retrieval probe.

Cognitive Aware Interference Mitigation Scheme for OFDMA Femtocells

KAUST Repository

Alqerm, Ismail

2015-04-09

Femto-cells deployment in today’s cellular networks came into practice to fulfill the increasing demand for data services. It also extends the coverage in the indoor areas. However, interference to other femto and macro-cells users remains an unresolved challenge. In this paper, we propose an interference mitigation scheme to control the cross-tier interference caused by femto-cells to the macro users and the co-tier interference among femtocells. Cognitive radio spectrum sensing capability is utilized to determine the non-occupied channels or the ones that cause minimal interference to the macro users. An awareness based channel allocation scheme is developed with the assistance of the graph-coloring algorithm to assign channels to the femto-cells base stations with power optimization, minimal interference, maximum throughput, and maximum spectrum efficiency. In addition, the scheme exploits negotiation capability to match traffic load and QoS with the channel, and to maintain efficient utilization of the available channels.

Exploiting Genetic Interference for Antiviral Therapy.

Directory of Open Access Journals (Sweden)

Elizabeth J Tanner

2016-05-01

Full Text Available Rapidly evolving viruses are a major threat to human health. Such viruses are often highly pathogenic (e.g., influenza virus, HIV, Ebola virus and routinely circumvent therapeutic intervention through mutational escape. Error-prone genome replication generates heterogeneous viral populations that rapidly adapt to new selection pressures, leading to resistance that emerges with treatment. However, population heterogeneity bears a cost: when multiple viral variants replicate within a cell, they can potentially interfere with each other, lowering viral fitness. This genetic interference can be exploited for antiviral strategies, either by taking advantage of a virus's inherent genetic diversity or through generating de novo interference by engineering a competing genome. Here, we discuss two such antiviral strategies, dominant drug targeting and therapeutic interfering particles. Both strategies harness the power of genetic interference to surmount two particularly vexing obstacles-the evolution of drug resistance and targeting therapy to high-risk populations-both of which impede treatment in resource-poor settings.

A homology sound-based algorithm for speech signal interference

Science.gov (United States)

Jiang, Yi-jiao; Chen, Hou-jin; Li, Ju-peng; Zhang, Zhan-song

2015-12-01

Aiming at secure analog speech communication, a homology sound-based algorithm for speech signal interference is proposed in this paper. We first split speech signal into phonetic fragments by a short-term energy method and establish an interference noise cache library with the phonetic fragments. Then we implement the homology sound interference by mixing the randomly selected interferential fragments and the original speech in real time. The computer simulation results indicated that the interference produced by this algorithm has advantages of real time, randomness, and high correlation with the original signal, comparing with the traditional noise interference methods such as white noise interference. After further studies, the proposed algorithm may be readily used in secure speech communication.

The Survival Advantage: Underlying Mechanisms and Extant Limitations

Directory of Open Access Journals (Sweden)

Stephanie A. Kazanas

2015-04-01

Full Text Available Recently, researchers have begun to investigate the function of memory in our evolutionary history. According to Nairne and colleagues (e.g., Nairne, Pandeirada, and Thompson, 2008; Nairne, Thompson, and Pandeirada, 2007, the best mnemonic strategy for learning lists of unrelated words may be one that addresses the same problems that our Pleistocene ancestors faced: fitness-relevant problems including securing food and water, as well as protecting themselves from predators. Survival processing has been shown to promote better recall and recognition memory than many well-known mnemonic strategies (e.g., pleasantness ratings, imagery, generation, etc.. However, the survival advantage does not extend to all types of stimuli and tasks. The current review presents research that has replicated Nairne et al.'s (2007 original findings, in addition to the research designs that fail to replicate the survival advantage. In other words, there are specific manipulations in which survival processing does not appear to benefit memory any more than other strategies. Potential mechanisms for the survival advantage are described, with an emphasis on those that are the most plausible. These proximate mechanisms outline the memory processes that may contribute to the advantage, although the ultimate mechanism may be the congruity between the survival scenario and Pleistocene problem-solving.

Interference contrast in multi-source few photon optics

OpenAIRE

Laskowski, Wieslaw; Wiesniak, Marcin; Zukowski, Marek; Bourennane, Mohamed; Weinfurter, Harald

2009-01-01

Many recent experiments employ several parametric down conversion (PDC) sources to get multiphoton interference. Such interference has applications in quantum information. We study here how effects due to photon statistics, misalignment, and partial distinguishability of the PDC pairs originating from different sources may lower the interference contrast in the multiphoton experiments.

Evolution of learning in fluctuating environments: when selection favors both social and exploratory individual learning.

Science.gov (United States)

Borenstein, Elhanan; Feldman, Marcus W; Aoki, Kenichi

2008-03-01

Cumulative cultural change requires organisms that are capable of both exploratory individual learning and faithful social learning. In our model, an organism's phenotype is initially determined innately (by its genotypic value) or by social learning (copying a phenotype from the parental generation), and then may or may not be modified by individual learning (exploration around the initial phenotype). The environment alternates periodically between two states, each defined as a certain range of phenotypes that can survive. These states may overlap, in which case the same phenotype can survive in both states, or they may not. We find that a joint social and exploratory individual learning strategy-the strategy that supports cumulative culture-is likely to spread when the environmental states do not overlap. In particular, when the environmental states are contiguous and mutation is allowed among the genotypic values, this strategy will spread in either moderately or highly stable environments, depending on the exact nature of the individual learning applied. On the other hand, natural selection often favors a social learning strategy without exploration when the environmental states overlap. We find only partial support for the "consensus" view, which holds that individual learning, social learning, and innate determination of behavior will evolve at short, intermediate, and long environmental periodicities, respectively.

Interference, reduced action, and trajectories

OpenAIRE

Floyd, Edward R.

2006-01-01

Instead of investigating the interference between two stationary, rectilinear wave functions in a trajectory representation by examining the two rectilinear wave functions individually, we examine a dichromatic wave function that is synthesized from the two interfering wave functions. The physics of interference is contained in the reduced action for the dichromatic wave function. As this reduced action is a generator of the motion for the dichromatic wave function, it determines the dichroma...

Interference of Spin-2 Self-Dual Modes

OpenAIRE

Ilha, Anderson; Wotzasek, Clovis

2001-01-01

We study the effects of interference between the self-dual and anti self-dual massive modes of the linearized Einstein-Chern-Simons topological gravity. The dual models to be used in the interference process are carefully analyzed with special emphasis on their propagating spectrum. We identify the opposite dual aspects, necessary for the application of the interference formalism on this model. The soldered theory so obtained displays explicitly massive modes of the Proca type. It may also be...

Enhanced machine learning scheme for energy efficient resource allocation in 5G heterogeneous cloud radio access networks

KAUST Repository

Alqerm, Ismail

2018-02-15

Heterogeneous cloud radio access networks (H-CRAN) is a new trend of 5G that aims to leverage the heterogeneous and cloud radio access networks advantages. Low power remote radio heads (RRHs) are exploited to provide high data rates for users with high quality of service requirements (QoS), while high power macro base stations (BSs) are deployed for coverage maintenance and low QoS users support. However, the inter-tier interference between the macro BS and RRHs and energy efficiency are critical challenges that accompany resource allocation in H-CRAN. Therefore, we propose a centralized resource allocation scheme using online learning, which guarantees interference mitigation and maximizes energy efficiency while maintaining QoS requirements for all users. To foster the performance of such scheme with a model-free learning, we consider users\\' priority in resource blocks (RBs) allocation and compact state representation based learning methodology to enhance the learning process. Simulation results confirm that the proposed resource allocation solution can mitigate interference, increase energy and spectral efficiencies significantly, and maintain users\\' QoS requirements.

Cooperation for Interference Management: A GDoF Perspective

KAUST Repository

Gherekhloo, Soheil

2016-10-13

The impact of cooperation on interference management is investigated by studying an elemental wireless network, the so-called symmetric interference relay channel (IRC), from a generalized degrees of freedom (GDoF) perspective. This is motivated by the fact that the deployment of relays is considered as a remedy to overcome the bottleneck of current systems in terms of achievable rates. The focus of this paper is on the regime in which the interference link is weaker than the source-relay link in the IRC. Our approach toward studying the GDoF goes through the capacity analysis of the linear deterministic IRC (LD-IRC). New upper bounds on the sum capacity of the LD-IRC based on genie-aided approaches are established. These upper bounds together with some existing upper bounds are achieved by using four novel transmission schemes. Extending the upper bounds and the transmission schemes to the Gaussian case, the GDoF of the Gaussian IRC is characterized for the aforementioned regime. This completes the GDoF results available in the literature for the symmetric GDoF. It turns out that even if the incoming and outgoing links of the relay are both weaker than the desired channel, involving a relay can increase the GDoF. Interestingly, utilizing the relay in this case can increase the slope of the GDoF from -2 [in the interference channel (IC)] to -1 or 0. This shrinks the regime where ignoring the interference by treating it as noise is optimal. Furthermore, the analysis shows that if the relay ingoing and outgoing links are sufficiently strong, the relay is able to neutralize the interference completely. In this case, the bottleneck of the transmission will be the interference links, and hence, the GDoF increases if the interference link gets stronger. It is shown that in the strong interference regime, in contrast to the IC, the GDoF can be a monotonically decreasing function of the interference level. © 1963-2012 IEEE.

Vasoactive intestinal peptide and electrical activity influence neuronal survival

International Nuclear Information System (INIS)

Brenneman, D.E.; Eiden, L.E.

1986-01-01

Blockage of electrical activity in dissociated spinal cord cultures results in a significant loss of neurons during a critical period in development. Decreases in neuronal cell numbers and 125 I-labeled tetanus toxin fixation produced by electrical blockage with tetrodotoxin (TTX) were prevented by addition of vasoactive intestinal peptide (VIP) to the nutrient medium. The most effective concentration of VIP was 0.1 nM. At higher concentrations, the survival-enhancing effect of VIP on TTX-treated cultures was attenuated. Addition of the peptide alone had no significant effect on neuronal cell counts or tetanus toxin fixation. With the same experimental conditions, two closely related peptides, PHI-27 (peptide, histidyl-isoleucine amide) and secretin, were found not to increase the number of neurons in TTX-treated cultures. Interference with VIP action by VIP antiserum resulted in neuronal losses that were not significantly different from those observed after TTX treatment. These data indicate that under conditions of electrical blockade a neurotrophic action of VIP on neuronal survival can be demonstrated

Interference-Robust Transmission in Wireless Sensor Networks.

Science.gov (United States)

Han, Jin-Seok; Lee, Yong-Hwan

2016-11-14

Low-power wireless sensor networks (WSNs) operating in unlicensed spectrum bands may seriously suffer from interference from other coexisting radio systems, such as IEEE 802.11 wireless local area networks. In this paper, we consider the improvement of the transmission performance of low-power WSNs by adjusting the transmission rate and the payload size in response to the change of co-channel interference. We estimate the probability of transmission failure and the data throughput and then determine the payload size to maximize the throughput performance. We investigate that the transmission time maximizing the normalized throughput is not much affected by the transmission rate, but rather by the interference condition. We adjust the transmission rate and the transmission time in response to the change of the channel and interference condition, respectively. Finally, we verify the performance of the proposed scheme by computer simulation. The simulation results show that the proposed scheme significantly improves data throughput compared with conventional schemes while preserving energy efficiency even in the presence of interference.

Epulis and pyogenic granuloma with occlusal interference

Directory of Open Access Journals (Sweden)

Widowati Witjaksono

2005-06-01

Full Text Available In dental clinic of Hospital University Science Malaysia (HUSM, there were cases with Localized Gingival Enlargement (LGE in the oral cavity with occlusal interference. In this study, three cases were observed. They were a 13 - year- old female with fibrous lge around 31 and 32 with occlusal interference in protrusive movement due to X bite, a 15 - year – old female with pyogenic granuloma near 11 & 21 with occlusal interference due to deep bite; and a 24 – year – old female who was eight months in pregnancy with pyogenic granuloma on the 34-35 and severe generalized pregnancy gingivitis with occlusal interference in centric occlusion and lateral movement. Clinical and histopathological diagnosis of the first case showed fibrous epulis, whereas the second and third cases disclosed pyogenic granuloma. Chronic trauma of the gingiva due to occlusal interference was assumed to be the cause of those LGE in case 1 and 2, while in case 3 poor oral hygiene and chronic trauma were assumed to be the etiologic factors.

Can Survival Processing Enhance Story Memory? Testing the Generalizability of the Adaptive Memory Framework

Science.gov (United States)

Seamon, John G.; Bohn, Justin M.; Coddington, Inslee E.; Ebling, Maritza C.; Grund, Ethan M.; Haring, Catherine T.; Jang, Sue-Jung; Kim, Daniel; Liong, Christopher; Paley, Frances M.; Pang, Luke K.; Siddique, Ashik H.

2012-01-01

Research from the adaptive memory framework shows that thinking about words in terms of their survival value in an incidental learning task enhances their free recall relative to other semantic encoding strategies and intentional learning (Nairne, Pandeirada, & Thompson, 2008). We found similar results. When participants used incidental…

Radio frequency interference mitigation using deep convolutional neural networks

Science.gov (United States)

Akeret, J.; Chang, C.; Lucchi, A.; Refregier, A.

2017-01-01

We propose a novel approach for mitigating radio frequency interference (RFI) signals in radio data using the latest advances in deep learning. We employ a special type of Convolutional Neural Network, the U-Net, that enables the classification of clean signal and RFI signatures in 2D time-ordered data acquired from a radio telescope. We train and assess the performance of this network using the HIDE &SEEK radio data simulation and processing packages, as well as early Science Verification data acquired with the 7m single-dish telescope at the Bleien Observatory. We find that our U-Net implementation is showing competitive accuracy to classical RFI mitigation algorithms such as SEEK's SUMTHRESHOLD implementation. We publish our U-Net software package on GitHub under GPLv3 license.

Minimum Interference Planar Geometric Topology in Wireless Sensor Networks

Science.gov (United States)

Nguyen, Trac N.; Huynh, Dung T.

The approach of using topology control to reduce interference in wireless sensor networks has attracted attention of several researchers. There are at least two definitions of interference in the literature. In a wireless sensor network the interference at a node may be caused by an edge that is transmitting data [15], or it occurs because the node itself is within the transmission range of another [3], [1], [6]. In this paper we show that the problem of assigning power to nodes in the plane to yield a planar geometric graph whose nodes have bounded interference is NP-complete under both interference definitions. Our results provide a rigorous proof for a theorem in [15] whose proof is unconvincing. They also address one of the open issues raised in [6] where Halldórsson and Tokuyama were concerned with the receiver model of node interference, and derived an O(sqrt {Δ}) upper bound for the maximum node interference of a wireless ad hoc network in the plane (Δ is the maximum interference of the so-called uniform radius network). The question as to whether this problem is NP-complete in the 2-dimensional case was left open.

Expectation-maximization algorithms for learning a finite mixture of univariate survival time distributions from partially specified class values

Energy Technology Data Exchange (ETDEWEB)

Lee, Youngrok [Iowa State Univ., Ames, IA (United States)

2013-05-15

Heterogeneity exists on a data set when samples from di erent classes are merged into the data set. Finite mixture models can be used to represent a survival time distribution on heterogeneous patient group by the proportions of each class and by the survival time distribution within each class as well. The heterogeneous data set cannot be explicitly decomposed to homogeneous subgroups unless all the samples are precisely labeled by their origin classes; such impossibility of decomposition is a barrier to overcome for estimating nite mixture models. The expectation-maximization (EM) algorithm has been used to obtain maximum likelihood estimates of nite mixture models by soft-decomposition of heterogeneous samples without labels for a subset or the entire set of data. In medical surveillance databases we can find partially labeled data, that is, while not completely unlabeled there is only imprecise information about class values. In this study we propose new EM algorithms that take advantages of using such partial labels, and thus incorporate more information than traditional EM algorithms. We particularly propose four variants of the EM algorithm named EM-OCML, EM-PCML, EM-HCML and EM-CPCML, each of which assumes a specific mechanism of missing class values. We conducted a simulation study on exponential survival trees with five classes and showed that the advantages of incorporating substantial amount of partially labeled data can be highly signi cant. We also showed model selection based on AIC values fairly works to select the best proposed algorithm on each specific data set. A case study on a real-world data set of gastric cancer provided by Surveillance, Epidemiology and End Results (SEER) program showed a superiority of EM-CPCML to not only the other proposed EM algorithms but also conventional supervised, unsupervised and semi-supervised learning algorithms.

47 CFR 24.237 - Interference protection.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Interference protection. 24.237 Section 24.237... SERVICES Broadband PCS § 24.237 Interference protection. (a) All licensees are required to coordinate their... protection criterion shall be such that the interfering signal will not produce more than 1.0 dB degradation...

Event-based proactive interference in rhesus monkeys.

Science.gov (United States)

Devkar, Deepna T; Wright, Anthony A

2016-10-01

Three rhesus monkeys (Macaca mulatta) were tested in a same/different memory task for proactive interference (PI) from prior trials. PI occurs when a previous sample stimulus appears as a test stimulus on a later trial, does not match the current sample stimulus, and the wrong response "same" is made. Trial-unique pictures (scenes, objects, animals, etc.) were used on most trials, except on trials where the test stimulus matched potentially interfering sample stimulus from a prior trial (1, 2, 4, 8, or 16 trials prior). Greater interference occurred when fewer trials separated interference and test. PI functions showed a continuum of interference. Delays between sample and test stimuli and intertrial intervals were manipulated to test how PI might vary as a function of elapsed time. Contrary to a similar study with pigeons, these time manipulations had no discernable effect on the monkey's PI, as shown by compete overlap of PI functions with no statistical differences or interactions. These results suggested that interference was strictly based upon the number of intervening events (trials with other pictures) without regard to elapsed time. The monkeys' apparent event-based interference was further supported by retesting with a novel set of 1,024 pictures. PI from novel pictures 1 or 2 trials prior was greater than from familiar pictures, a familiar set of 1,024 pictures. Moreover, when potentially interfering novel stimuli were 16 trials prior, performance accuracy was actually greater than accuracy on baseline trials (no interference), suggesting that remembering stimuli from 16 trials prior was a cue that this stimulus was not the sample stimulus on the current trial-a somewhat surprising conclusion particularly given monkeys.

Complexity for survival of livings

Energy Technology Data Exchange (ETDEWEB)

Zak, Michail [Jet Propulsion Laboratory, California Institute of Technology, Advance Computing Algorithms and IVHM Group, Pasadena, CA 91109 (United States)]. E-mail: Michail.Zak@jpl.nasa.gov

2007-05-15

A connection between survivability of livings and complexity of their behavior is established. New physical paradigms-exchange of information via reflections, and chain of abstractions-explaining and describing progressive evolution of complexity in living (active) systems are introduced. A biological origin of these paradigms is associated with a recently discovered mirror neuron that is able to learn by imitation. As a result, an active element possesses the self-nonself images and interacts with them creating the world of mental dynamics. Three fundamental types of complexity of mental dynamics that contribute to survivability are identified. Mathematical model of the corresponding active systems is described by coupled motor-mental dynamics represented by Langevin and Fokker-Planck equations, respectively, while the progressive evolution of complexity is provided by nonlinear evolution of probability density. Application of the proposed formalism to modeling common-sense-based decision-making process is discussed.

Complexity for survival of livings

International Nuclear Information System (INIS)

Zak, Michail

2007-01-01

A connection between survivability of livings and complexity of their behavior is established. New physical paradigms-exchange of information via reflections, and chain of abstractions-explaining and describing progressive evolution of complexity in living (active) systems are introduced. A biological origin of these paradigms is associated with a recently discovered mirror neuron that is able to learn by imitation. As a result, an active element possesses the self-nonself images and interacts with them creating the world of mental dynamics. Three fundamental types of complexity of mental dynamics that contribute to survivability are identified. Mathematical model of the corresponding active systems is described by coupled motor-mental dynamics represented by Langevin and Fokker-Planck equations, respectively, while the progressive evolution of complexity is provided by nonlinear evolution of probability density. Application of the proposed formalism to modeling common-sense-based decision-making process is discussed

Codebook-based interference alignment for uplink MIMO interference channels

KAUST Repository

Lee, Hyun Ho

2014-02-01

In this paper, we propose a codebook-based interference alignment (IA) scheme in the constant multiple-input multipleoutput (MIMO) interference channel especially for the uplink scenario. In our proposed scheme, we assume cooperation among base stations (BSs) through reliable backhaul links so that global channel knowledge is available for all BSs, which enables BS to compute the transmit precoder and inform its quantized index to the associated user via limited rate feedback link.We present an upper bound on the rate loss of the proposed scheme and derive the scaling law of the feedback load tomaintain a constant rate loss relative to IA with perfect channel knowledge. Considering the impact of overhead due to training, cooperation, and feedback, we address the effective degrees of freedom (DOF) of the proposed scheme and derive the maximization of the effective DOF. From simulation results, we verify our analysis on the scaling law to preserve the multiplexing gain and confirm that the proposed scheme is more effective than the conventional IA scheme in terms of the effective DOF. © 2014 KICS.

Lessons from Cacti: How to Survive the Prickles of Life during Tough Times

Science.gov (United States)

Bigger, Alan S.; Bigger, Linda B.

2009-01-01

The saguaro cactus looked a little like humans, in different shapes and sizes. How on earth do they survive in a climate that seems so inhospitable? It is possible to learn lessons for life from a cactus, if one can only get beyond the thorns, and that these lessons will assist one to survive during tough or prickly times. These plants survive…

Learning new meanings for known words: Biphasic effects of prior knowledge

OpenAIRE

Fang, Xiaoping; Perfetti, Charles; Stafura, Joseph

2016-01-01

In acquiring word meanings, learners are often confronted by a single word form that is mapped to two or more meanings. For example, long after how to roller-“skate”, one may learn that “skate” is also a kind of fish. Such learning of new meanings for familiar words involves two potentially contrasting processes, relative to new form-new meaning learning: 1) Form-based familiarity may facilitate learning a new meaning, and 2) meaning-based interference may inhibit learning a new meaning. We e...

Generalized Multiphoton Quantum Interference

Directory of Open Access Journals (Sweden)

Max Tillmann

2015-10-01

Full Text Available Nonclassical interference of photons lies at the heart of optical quantum information processing. Here, we exploit tunable distinguishability to reveal the full spectrum of multiphoton nonclassical interference. We investigate this in theory and experiment by controlling the delay times of three photons injected into an integrated interferometric network. We derive the entire coincidence landscape and identify transition matrix immanants as ideally suited functions to describe the generalized case of input photons with arbitrary distinguishability. We introduce a compact description by utilizing a natural basis that decouples the input state from the interferometric network, thereby providing a useful tool for even larger photon numbers.

Interference of two photons in parametric down conversion

International Nuclear Information System (INIS)

Ghosh, R.; Hong, C.K.; Ou, Z.Y.; Mandel, L.

1986-01-01

A theoretical treatment is given of the process in which the two photons produced simultaneously in the parametric frequency splitting of light are allowed to interfere. It is shown that, while there is no interference in the usual sense involving quantities that are of the second order in the field, fourth-order interference effects are present. These may be revealed by measuring the joint probability of detecting two photons at two points x,x' in the interference plane with photoelectric detectors as a function of the separation x-x'. The probability exhibits a cosine modulation with x-x', with visibility that can approach 100%, even though the integration time in the experiment may greatly exceed the reciprocal bandwidth of the photons. The interference effect has a nonclassical origin and implies a violation of local realism in the highly correlated two-photon state

Does interference competition with wolves limit the distribution and abundance of coyotes?

Science.gov (United States)

Berger, Kim Murray; Gese, Eric M

2007-11-01

Interference competition with wolves Canis lupus is hypothesized to limit the distribution and abundance of coyotes Canis latrans, and the extirpation of wolves is often invoked to explain the expansion in coyote range throughout much of North America. We used spatial, seasonal and temporal heterogeneity in wolf distribution and abundance to test the hypothesis that interference competition with wolves limits the distribution and abundance of coyotes. From August 2001 to August 2004, we gathered data on cause-specific mortality and survival rates of coyotes captured at wolf-free and wolf-abundant sites in Grand Teton National Park (GTNP), Wyoming, USA, to determine whether mortality due to wolves is sufficient to reduce coyote densities. We examined whether spatial segregation limits the local distribution of coyotes by evaluating home-range overlap between resident coyotes and wolves, and by contrasting dispersal rates of transient coyotes captured in wolf-free and wolf-abundant areas. Finally, we analysed data on population densities of both species at three study areas across the Greater Yellowstone Ecosystem (GYE) to determine whether an inverse relationship exists between coyote and wolf densities. Although coyotes were the numerically dominant predator, across the GYE, densities varied spatially and temporally in accordance with wolf abundance. Mean coyote densities were 33% lower at wolf-abundant sites in GTNP, and densities declined 39% in Yellowstone National Park following wolf reintroduction. A strong negative relationship between coyote and wolf densities (beta = -3.988, P wolves limits coyote populations. Overall mortality of coyotes resulting from wolf predation was low, but wolves were responsible for 56% of transient coyote deaths (n = 5). In addition, dispersal rates of transient coyotes captured at wolf-abundant sites were 117% higher than for transients captured in wolf-free areas. Our results support the hypothesis that coyote abundance is

Two-state vector formalism and quantum interference

International Nuclear Information System (INIS)

Hashmi, F A; Li, Fu; Zhu, Shi-Yao; Zubairy, M Suhail

2016-01-01

We show that two-state vector formalism (TSVF), applied to quantum systems that make use of delicate interference effects, can lead to paradoxes. We consider a few schemes of nested Mach–Zehnder interferometers that make use of destructive interference. A particular interpretation of TSVF applied to these schemes makes predictions that are contradictory to quantum theory and can not always be verified. Our results suggest that TSVF might not be a suitable tool to describe quantum systems that make use of delicate quantum interference effects. (paper)

Probing two-centre interference in molecular high harmonic generation

International Nuclear Information System (INIS)

Vozzi, C; Calegari, F; Benedetti, E; Berlasso, R; Sansone, G; Stagira, S; Nisoli, M; Altucci, C; Velotta, R; Torres, R; Heesel, E; Kajumba, N; Marangos, J P

2006-01-01

Two-centre interference in the recombination step of molecular high harmonic generation (HHG) has been probed in CO 2 and O 2 . We report the order dependence of characteristic enhancements or suppressions of high harmonic production in aligned samples of both molecules. In CO 2 , a robust destructive interference was seen consistent with the known separation of the oxygen atoms that are active in HHG. In O 2 , a harmonic enhancement was found indicating constructive interference. A good agreement was found with a simple two-centre interference model that includes the angular distribution function of the sample. The effective momentum of the electron wave was determined from the spectral position of these interferences. Ellipticity-dependent studies in CO 2 clearly show how the destructive interference can be 'switched off' by increasing the degree of ellipticity and thus shifting the effective resonance condition

Interference lithography for optical devices and coatings

Science.gov (United States)

Juhl, Abigail Therese

Interference lithography can create large-area, defect-free nanostructures with unique optical properties. In this thesis, interference lithography will be utilized to create photonic crystals for functional devices or coatings. For instance, typical lithographic processing techniques were used to create 1, 2 and 3 dimensional photonic crystals in SU8 photoresist. These structures were in-filled with birefringent liquid crystal to make active devices, and the orientation of the liquid crystal directors within the SU8 matrix was studied. Most of this thesis will be focused on utilizing polymerization induced phase separation as a single-step method for fabrication by interference lithography. For example, layered polymer/nanoparticle composites have been created through the one-step two-beam interference lithographic exposure of a dispersion of 25 and 50 nm silica particles within a photopolymerizable mixture at a wavelength of 532 nm. In the areas of constructive interference, the monomer begins to polymerize via a free-radical process and concurrently the nanoparticles move into the regions of destructive interference. The holographic exposure of the particles within the monomer resin offers a single-step method to anisotropically structure the nanoconstituents within a composite. A one-step holographic exposure was also used to fabricate self-healing coatings that use water from the environment to catalyze polymerization. Polymerization induced phase separation was used to sequester an isocyanate monomer within an acrylate matrix. Due to the periodic modulation of the index of refraction between the monomer and polymer, the coating can reflect a desired wavelength, allowing for tunable coloration. When the coating is scratched, polymerization of the liquid isocyanate is catalyzed by moisture in air; if the indices of the two polymers are matched, the coatings turn transparent after healing. Interference lithography offers a method of creating multifunctional self

Assessment of life interference in anxious children

DEFF Research Database (Denmark)

Rapee, Ronald; Thastum, Mikael; Chavira, Denise

associated with mental disorders arguably the key issue of relevance to both sufferers and therapists. Yet among both childhood and adult disorders the primary focus in terms of assessment and treatment is on symptoms, with far less attention paid to the impact of these symptoms on the sufferer's life....... This imbalance has particularly characterised research on child anxiety where few studies have examined either the impact of anxiety disorders on children's lives or the effects of treatments on life interference. To some extent this lack of attention has come from a lack of well developed measures to assess...... life interference derived from symptoms of anxiety. Broader and more general life interference measures tend to have minimal relevance for children with anxiety disorders. The current paper will describe two measures of life interference that have been developed at the Centre for Emotional Health...

Conducted Electromagnetic Interference (EMI) in Smart Grids

CERN Document Server

Smolenski, Robert

2012-01-01

As power systems develop to incorporate renewable energy sources, the delivery systems may be disrupted by the changes involved. The grid’s technology and management must be developed to form Smart Grids between consumers, suppliers and producers. Conducted Electromagnetic Interference (EMI) in Smart Grids considers the specific side effects related to electromagnetic interference (EMI) generated by the application of these Smart Grids. Conducted Electromagnetic Interference (EMI) in Smart Grids presents specific EMI conducted phenomena as well as effective methods to filter and handle them once identified. After introduction to Smart Grids, the following sections cover dedicated methods for EMI reduction and potential avenues for future development including chapters dedicated to: •potential system services, •descriptions of the EMI spectra shaping methods, •methods of interference voltage compensation, and theoretical analysis of experimental results.  By focusing on these key aspects, Conducted El...

Signal noise/interferer combiner unit programmable (SINCUP)

Science.gov (United States)

Martinezdepison, Emilio

1988-12-01

The Signal Noise Interferer Combiner Unit Programmable (SINCUP) has been developed to facilitate laboratory performance testing of Very Low Frequency (VLF/Low Frequency (LF) receivers. To accomplish this, the unit allows the combining in controlled amounts of various real-world environmental and manmade interference with an information carrying signal. The externally modulated signal is combined with internally/externally generated Gaussian noise and/or with an internally/externally generated interferer. In order to test modern digital processing techniques, such as Adaptive Null Steering, Eigenvector Sorting, and Widrow-Hoff adaptive filters, SINCUP is capable of generating and meeting much higher signal-to-noise plus interference ratios than earlier channel simulators. The present software has been written to accommodate a dynamic signal-to-noise ratio (SNR) range from -60 to +60 dB. Higher dynamic range units could be implemented.

Does perceptual learning require consciousness or attention?

Science.gov (United States)

Meuwese, Julia D I; Post, Ruben A G; Scholte, H Steven; Lamme, Victor A F

2013-10-01

It has been proposed that visual attention and consciousness are separate [Koch, C., & Tsuchiya, N. Attention and consciousness: Two distinct brain processes. Trends in Cognitive Sciences, 11, 16-22, 2007] and possibly even orthogonal processes [Lamme, V. A. F. Why visual attention and awareness are different. Trends in Cognitive Sciences, 7, 12-18, 2003]. Attention and consciousness converge when conscious visual percepts are attended and hence become available for conscious report. In such a view, a lack of reportability can have two causes: the absence of attention or the absence of a conscious percept. This raises an important question in the field of perceptual learning. It is known that learning can occur in the absence of reportability [Gutnisky, D. A., Hansen, B. J., Iliescu, B. F., & Dragoi, V. Attention alters visual plasticity during exposure-based learning. Current Biology, 19, 555-560, 2009; Seitz, A. R., Kim, D., & Watanabe, T. Rewards evoke learning of unconsciously processed visual stimuli in adult humans. Neuron, 61, 700-707, 2009; Seitz, A. R., & Watanabe, T. Is subliminal learning really passive? Nature, 422, 36, 2003; Watanabe, T., Náñez, J. E., & Sasaki, Y. Perceptual learning without perception. Nature, 413, 844-848, 2001], but it is unclear which of the two ingredients-consciousness or attention-is not necessary for learning. We presented textured figure-ground stimuli and manipulated reportability either by masking (which only interferes with consciousness) or with an inattention paradigm (which only interferes with attention). During the second session (24 hr later), learning was assessed neurally and behaviorally, via differences in figure-ground ERPs and via a detection task. Behavioral and neural learning effects were found for stimuli presented in the inattention paradigm and not for masked stimuli. Interestingly, the behavioral learning effect only became apparent when performance feedback was given on the task to measure learning

Toponium-Z0 interference and phenomenology of an extra Z0 in e+e- collisions

International Nuclear Information System (INIS)

Franzini, P.J.

1987-01-01

A qualitative discussion of toponium-Z 0 interference is followed by a brief discussion of heavy quark potentials and the spectrum of toponium states which results. The results of the toponium spectra and the mixing formalism are then used to find the cross sections and asymmetries for toponium near the Z. The phenomenology of two-Higgs models and the bounds imposed on them by their effects on neutral B meson mixing are discussed, followed by the effects an extra Higgs doublet may have on toponium-Z 0 interference. The topic then turns to phenomenology of an extra Z 0 in electron-positron collisions. Models under consideration are reviewed, and the existing limits on such models are considered. What can be learned by electron-positron annihilation measurements at the Z peak without polarized beams is discussed, as well as further restrictions that can be made with polarized beams. The potential for experiments in the energy region above the Z is discussed. 57 refs

Autonomy, Competence and Non-interference.

Science.gov (United States)

Roberts, Joseph T F

2017-12-30

In light of the variety of uses of the term autonomy in recent bioethics literature, in this paper, I suggest that competence, not being as contested, is better placed to play the anti-paternalistic role currently assigned to autonomy. The demonstration of competence, I will argue, can provide individuals with robust spheres of non-interference in which they can pursue their lives in accordance with their own values. This protection from paternalism is achieved by granting individuals rights to non-interference upon demonstration of competence. In this paper, I present a risk-sensitive account of competence as a means of grounding rights to non-interference. On a risk-sensitive account of competence individuals demonstrate their competence by exercising three capacities to the extent necessary to meet a threshold determined by the riskiness of the decision. These three capacities are the capacity to (i) acquire knowledge, (ii) use instrumental rationality, and (iii) form and revise a life plan.

Neural correlates of interference resolution in the multi-source interference task: a meta-analysis of functional neuroimaging studies.

Science.gov (United States)

Deng, Yuqin; Wang, Xiaochun; Wang, Yan; Zhou, Chenglin

2018-04-10

Interference resolution refers to cognitive control processes enabling one to focus on task-related information while filtering out unrelated information. But the exact neural areas, which underlie a specific cognitive task on interference resolution, are still equivocal. The multi-source interference task (MSIT), as a particular cognitive task, is a well-established experimental paradigm used to evaluate interference resolution. Studies combining the MSIT with functional magnetic resonance imaging (fMRI) have shown that the MSIT evokes the dorsal anterior cingulate cortex (dACC) and cingulate-frontal-parietal cognitive-attentional networks. However, these brain areas have not been evaluated quantitatively and these findings have not been replicated. In the current study, we firstly report a voxel-based meta-analysis of functional brain activation associated with the MSIT so as to identify the localization of interference resolution in such a specific cognitive task. Articles on MSIT-related fMRI published between 2003 and July 2017 were eligible. The electronic databases searched included PubMed, Web of Knowledge, and Google Scholar. Differential BOLD activation patterns between the incongruent and congruent condition were meta-analyzed in anisotropic effect-size signed differential mapping software. Robustness meta-analysis indicated that two significant activation clusters were shown to have reliable functional activity in comparisons between incongruent and congruent conditions. The first reliable activation cluster, which included the dACC, medial prefrontal cortex, supplementary motor area, replicated the previous MSIT-related fMRI study results. Furthermore, we found another reliable activation cluster comprising areas of the right insula, right inferior frontal gyrus, and right lenticular nucleus-putamen, which were not typically discussed in previous MSIT-related fMRI studies. The current meta-analysis study presents the reliable brain activation patterns

Proactive interference by cues presented without outcomes: Differences in context specificity of latent inhibition and conditioned inhibition.

Science.gov (United States)

Miguez, Gonzalo; McConnell, Bridget; Polack, Cody W; Miller, Ralph R

2018-01-08

This report is part of a larger project examining associative interference as a function of the nature of the interfering and target associations. Lick suppression experiments with rats assessed the effects of context shifts on proactive outcome interference by latent inhibition (LI) and Pavlovian conditioned inhibition (CI) treatments on subsequently trained Pavlovian conditioned excitation treatment. LI and CI were trained in Context A during Phase 1, and then excitation treatment was administered in Context B during Phase 2, followed by tests for conditioned excitation in Contexts A, B, or C. Experiment 1 preliminarily established our LI and CI treatments and resulted in equally retarded acquisition of behavioral control when the target cue was subsequently trained as a conditioned excitor and tested in Context A. However, only CI treatment caused the target to pass a summation test for inhibition. Centrally, Experiment 2 consisted of LI and CI treatments in Context A followed by excitatory training in Context B. Testing found low excitatory control by both LI and CI cues in Context A relative to strong excitatory control in Context B, but CI treatment transferred to Context C more strongly than LI treatment. Experiment 3 determined that LI treatment failed to transfer to Context C even when the number of LI trials was greatly increased. Thus, first-learned LI appears to be relatively context specific, whereas first-learned CI generalizes to a neutral context. These observations add to existing evidence that LI and CI treatments result in different types of learning that diverge sharply in transfer to a novel test context.

Sources of interference in item and associative recognition memory.

Science.gov (United States)

Osth, Adam F; Dennis, Simon

2015-04-01

A powerful theoretical framework for exploring recognition memory is the global matching framework, in which a cue's memory strength reflects the similarity of the retrieval cues being matched against the contents of memory simultaneously. Contributions at retrieval can be categorized as matches and mismatches to the item and context cues, including the self match (match on item and context), item noise (match on context, mismatch on item), context noise (match on item, mismatch on context), and background noise (mismatch on item and context). We present a model that directly parameterizes the matches and mismatches to the item and context cues, which enables estimation of the magnitude of each interference contribution (item noise, context noise, and background noise). The model was fit within a hierarchical Bayesian framework to 10 recognition memory datasets that use manipulations of strength, list length, list strength, word frequency, study-test delay, and stimulus class in item and associative recognition. Estimates of the model parameters revealed at most a small contribution of item noise that varies by stimulus class, with virtually no item noise for single words and scenes. Despite the unpopularity of background noise in recognition memory models, background noise estimates dominated at retrieval across nearly all stimulus classes with the exception of high frequency words, which exhibited equivalent levels of context noise and background noise. These parameter estimates suggest that the majority of interference in recognition memory stems from experiences acquired before the learning episode. (c) 2015 APA, all rights reserved).

High-Q Bandpass Comb Filter for Mains Interference Extraction

Directory of Open Access Journals (Sweden)

Neycheva T.

2009-12-01

Full Text Available This paper presents a simple digital high-Q bandpass comb filter for power-line (PL or other periodical interference extraction. The filter concept relies on a correlated signal average resulting in alternating constructive and destructive spectrum interference i.e. the so-called comb frequency response. The presented filter is evaluated by Matlab simulations with real ECG signal contaminated with low amplitude PL interference. The made simulations show that this filter accurately extract the PL interference. It has high-Q notches only at PL odd harmonics and is appropriate for extraction of any kind of odd harmonic interference including rectangular shape. The filter is suitable for real-time operation with popular low-cost microcontrollers.

Proposal of interference reduction routing for ad-hoc networks

Directory of Open Access Journals (Sweden)

Katsuhiro Naito

2010-10-01

Full Text Available In this paper, we propose an interference reduction routing protocol for ad-hoc networks. The interference is one of the degradation factors in wireless communications. In the ad-hoc network, some nodes communicate simultaneously. Therefore, these communications cause interference each other, and some packets are corrupted due to interference from another node. In the proposed protocol, each node estimates required transmission power according to hello messages. Therefore, the node can transmit a data packet with minimum required transmission power. Consequently, the interference against neighbor nodes can be reduced. From simulation results, we can find that the proposed protocol can reduce the number of control messages and can improve the throughput performance.

Interference Cancellation Using Space-Time Processing and Precoding Design

CERN Document Server

Li, Feng

2013-01-01

Interference Cancellation Using Space-Time Processing and Precoding Design introduces original design methods to achieve interference cancellation, low-complexity decoding and full diversity for a series of multi-user systems. In multi-user environments, co-channel interference will diminish the performance of wireless communications systems. In this book, we investigate how to design robust space-time codes and pre-coders to suppress the co-channel interference when multiple antennas are available.   This book offers a valuable reference work for graduate students, academic researchers and engineers who are interested in interference cancellation in wireless communications. Rigorous performance analysis and various simulation illustrations are included for each design method.   Dr. Feng Li is a scientific researcher at Cornell University.

An Evaluation of Deficits in Semantic Cuing, Proactive and Retroactive Interference as Early Features of Alzheimer’s disease

Science.gov (United States)

Crocco, Elizabeth; Curiel, Rosie E.; Acevedo, Amarilis; Czaja, Sara J.; Loewenstein, David A.

2015-01-01

OBJECTIVE To determine the degree to which susceptibility to different types of semantic interference may reflect the earliest manifestations of early Alzheimer disease (AD) beyond the effects of global memory impairment. METHODS Normal elderly (NE) subjects (n= 47), subjects with amnestic mild cognitive impairment (aMCI: n=34) and 40 subjects with probable AD were evaluated using a unique cued recall paradigm that allowed for an evaluation of both proactive and retroactive interference effects while controlling for global memory impairment (LASSI-L procedure). RESULTS Controlling for overall memory impairment, aMCI subjects had much greater proactive and retroactive interference effects than NE subjects. LASSI-L indices of learning using cued recall evidenced high levels of sensitivity and specificity with an overall correct classification rate of 90%. These provided better discrimination than traditional neuropsychological measures of memory function. CONCLUSION The LASSI-L paradigm is unique and unlike other assessments of memory in that items presented for cued recall are explicitly presented, and semantic interference and cuing effects can be assessed while controlling for initial level of memory impairment. This represents a powerful procedure allowing the participant to serve as his or her own control. The high levels of discrimination between subjects with aMCI and normal cognition that exceeded traditional neuropsychological measures makes the LASSI-L worthy of further research in the detection of early AD. PMID:23768680

Interference and protection of electromagnetic pulse to digital signal processor

International Nuclear Information System (INIS)

Wang Yan; Jiao Hongling; He Shanhong; Pan Chao; Feng Deren; Che Wenquan; Xiong Ying

2013-01-01

The effective electromagnetic pulse protection is studied in this paper, first the interference of electromagnetic pulse simulator path is analyzed, including the digital signal processor (DSP) and the discharge circuit of coupling interference and net electricity coupling interference. Using the structure optimization design, the hardware block reinforcement measurement and the setting of open software trap, and the watchdog anti-jamming measures, the interference test is completed such as the central processor core voltage of DSP, input/output (I/O) ports of DSP and the display screen. The experimental results show that the combination of hardware and software protection reinforcement technology is effective, and the interference pulse amplitude of DSP board I/O port and the kernel work voltage are reduced, and the interference duration is reduced from 2 μs to 400 ns. The interference pulse is effectively restrained. (authors)

Complete hazard ranking to analyze right-censored data: An ALS survival study.

Science.gov (United States)

Huang, Zhengnan; Zhang, Hongjiu; Boss, Jonathan; Goutman, Stephen A; Mukherjee, Bhramar; Dinov, Ivo D; Guan, Yuanfang

2017-12-01

Survival analysis represents an important outcome measure in clinical research and clinical trials; further, survival ranking may offer additional advantages in clinical trials. In this study, we developed GuanRank, a non-parametric ranking-based technique to transform patients' survival data into a linear space of hazard ranks. The transformation enables the utilization of machine learning base-learners including Gaussian process regression, Lasso, and random forest on survival data. The method was submitted to the DREAM Amyotrophic Lateral Sclerosis (ALS) Stratification Challenge. Ranked first place, the model gave more accurate ranking predictions on the PRO-ACT ALS dataset in comparison to Cox proportional hazard model. By utilizing right-censored data in its training process, the method demonstrated its state-of-the-art predictive power in ALS survival ranking. Its feature selection identified multiple important factors, some of which conflicts with previous studies.

Interference Effects in Strong-Field Dissociative Ionization

DEFF Research Database (Denmark)

Yue, Lun; Madsen, Lars Bojer

2015-01-01

with simple energy conservation arguments. We explain the structures as interferences between wave packets released during different optical cycles, and during the same optical cycle, respectively. Both inter- and intracycle interference structures are clearly visible in the joint energy spectra. The shapes...

Communication: Finding destructive interference features in molecular transport junctions

Energy Technology Data Exchange (ETDEWEB)

Reuter, Matthew G., E-mail: mgreuter@u.northwestern.edu [Department of Chemistry, Northwestern University, Evanston, Illinois 60208 (United States); Hansen, Thorsten [Department of Chemistry, H. C. Ørsted Institute, University of Copenhagen, DK 2100 Copenhagen (Denmark)

2014-11-14

Associating molecular structure with quantum interference features in electrode-molecule-electrode transport junctions has been difficult because existing guidelines for understanding interferences only apply to conjugated hydrocarbons. Herein we use linear algebra and the Landauer-Büttiker theory for electron transport to derive a general rule for predicting the existence and locations of interference features. Our analysis illustrates that interferences can be directly determined from the molecular Hamiltonian and the molecule–electrode couplings, and we demonstrate its utility with several examples.

Study on index system of GPS interference effect evaluation

Science.gov (United States)

Zhang, Kun; Zeng, Fangling; Zhao, Yuan; Zeng, Ruiqi

2018-05-01

Satellite navigation interference effect evaluation is the key technology to break through the research of Navigation countermeasure. To evaluate accurately the interference degree and Anti-jamming ability of GPS receiver, this text based on the existing research results of Navigation interference effect evaluation, build the index system of GPS receiver effectiveness evaluation from four levels of signal acquisition, tracking, demodulation and positioning/timing and establish the model for each index. These indexes can accurately and quantitatively describe the interference effect at all levels.

Kvantová interference

Czech Academy of Sciences Publication Activity Database

Peřina, Jan

2003-01-01

Roč. 48, č. 4 (2003), s. 99-103 ISSN 0447-6441 R&D Projects: GA MŠk LN00A015 Institutional research plan: CEZ:AV0Z1010921 Keywords : interference * quantum cryptography * quantum computing * quantum teleportation Subject RIV: BH - Optics, Masers, Lasers

Interference and memory capacity limitations.

Science.gov (United States)

Endress, Ansgar D; Szabó, Szilárd

2017-10-01

Working memory (WM) is thought to have a fixed and limited capacity. However, the origins of these capacity limitations are debated, and generally attributed to active, attentional processes. Here, we show that the existence of interference among items in memory mathematically guarantees fixed and limited capacity limits under very general conditions, irrespective of any processing assumptions. Assuming that interference (a) increases with the number of interfering items and (b) brings memory performance to chance levels for large numbers of interfering items, capacity limits are a simple function of the relative influence of memorization and interference. In contrast, we show that time-based memory limitations do not lead to fixed memory capacity limitations that are independent of the timing properties of an experiment. We show that interference can mimic both slot-like and continuous resource-like memory limitations, suggesting that these types of memory performance might not be as different as commonly believed. We speculate that slot-like WM limitations might arise from crowding-like phenomena in memory when participants have to retrieve items. Further, based on earlier research on parallel attention and enumeration, we suggest that crowding-like phenomena might be a common reason for the 3 major cognitive capacity limitations. As suggested by Miller (1956) and Cowan (2001), these capacity limitations might arise because of a common reason, even though they likely rely on distinct processes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Electric smog: telemetry interference between ICD and LVAD.

Science.gov (United States)

Duncker, David; König, Thorben; Müller-Leisse, Johanna; Michalski, Roman; Oswald, Hanno; Schmitto, Jan D; Bauersachs, Johann; Veltmann, Christian

2017-09-01

Electromagnetic interferences between implantable cardioverter/defibrillators (ICD) and left ventricular assist devices (LVAD) impacting telemetry have been described in previous generations of ICD as well as LVAD, but have been predominantly overcome in current ICD generations. After introduction of a new fully magnetically levitated centrifugal continuous-flow circulatory pump, we report a case of tenacious telemetry interference between the HeartMate 3 LVAD and an ICD after battery exchange to an Iforia 5. Initialization of the initial telemetry handshake was only possible using several specific maneuvers simultaneously. In order to exclude device-device interference, we suggest to place the ICD above the LVAD before implantation and to test for possible telemetry interferences.

Fingerprint extraction from interference destruction terahertz spectrum.

Science.gov (United States)

Xiong, Wei; Shen, Jingling

2010-10-11

In this paper, periodic peaks in a terahertz absorption spectrum are confirmed to be induced from interference effects. Theoretically, we explained the periodic peaks and calculated the locations of them. Accordingly, a technique was suggested, with which the interference peaks in a terahertz spectrum can be eliminated and therefore a real terahertz absorption spectrum can be obtained. Experimentally, a sample, Methamphetamine, was investigated and its terahertz fingerprint was successfully extracted from its interference destruction spectrum. This technique is useful in getting samples' terahertz fingerprint spectra, and furthermore provides a fast nondestructive testing method using a large size terahertz beam to identify materials.

'Quantum interference with slits' revisited

Science.gov (United States)

Rothman, Tony; Boughn, Stephen

2011-01-01

Marcella has presented a straightforward technique employing the Dirac formalism to calculate single- and double-slit interference patterns. He claims that no reference is made to classical optics or scattering theory and that his method therefore provides a purely quantum mechanical description of these experiments. He also presents his calculation as if no approximations are employed. We show that he implicitly makes the same approximations found in classical treatments of interference and that no new physics has been introduced. At the same time, some of the quantum mechanical arguments Marcella gives are, at best, misleading.

The effects of trait impulsivity on proactive and reactive interference control.

Science.gov (United States)

Xiang, Ling; Chen, Yan; Chen, Antao; Zhang, Fenghua; Xu, Fuming; Wang, Baoxi

2018-02-01

The current study used event-related brain potentials (ERPs) to explore whether self-reported trait impulsivity in healthy individuals might be differentially related to proactive and reactive interference control. Participants with high and low impulsivity (HI and LI, respectively) performed a modified version of the prime-target interference task. Proactive interference control was induced in the mostly incongruent (MI) context and reactive interference control was induced in the mostly congruent (MC) context. Although the behavioral data revealed no difference between HI and LI individuals in terms of the interference effects (incongruent - congruent) under both contexts, the ERP results showed that impulsivity has a different influence on the interference effects under different task contexts. In the MC context, the interference effects on the medial frontal negativity (MFN) and the negative sustained potential (N-SP) were greater, while that on the positive sustained potential (P-SP) were smaller in the HI compared to those in the LI group. This suggests that high levels of impulsivity might be associated with a reduced efficiency of the processes supporting reactive control to resolve interference when interference is not expected. In contrast, the three ERP indices (MFN, P-SP, and N-SP) of interference processing in the MI context were insensitive to variations in impulsivity. This suggests that HI individuals might be as effective as LI individuals in recruiting proactive control for sustained active maintenance of task goals to anticipate and prevent interference throughout the experimental blocks where interference occurs frequently. In conclusion, these results indicate that impulsivity has a more negative influence on reactive interference control than on proactive interference control. Copyright © 2017. Published by Elsevier B.V.

Widespread nanoparticle-assay interference: implications for nanotoxicity testing.

Science.gov (United States)

Ong, Kimberly J; MacCormack, Tyson J; Clark, Rhett J; Ede, James D; Ortega, Van A; Felix, Lindsey C; Dang, Michael K M; Ma, Guibin; Fenniri, Hicham; Veinot, Jonathan G C; Goss, Greg G

2014-01-01

The evaluation of engineered nanomaterial safety has been hindered by conflicting reports demonstrating differential degrees of toxicity with the same nanoparticles. The unique properties of these materials increase the likelihood that they will interfere with analytical techniques, which may contribute to this phenomenon. We tested the potential for: 1) nanoparticle intrinsic fluorescence/absorbance, 2) interactions between nanoparticles and assay components, and 3) the effects of adding both nanoparticles and analytes to an assay, to interfere with the accurate assessment of toxicity. Silicon, cadmium selenide, titanium dioxide, and helical rosette nanotubes each affected at least one of the six assays tested, resulting in either substantial over- or under-estimations of toxicity. Simulation of realistic assay conditions revealed that interference could not be predicted solely by interactions between nanoparticles and assay components. Moreover, the nature and degree of interference cannot be predicted solely based on our current understanding of nanomaterial behaviour. A literature survey indicated that ca. 95% of papers from 2010 using biochemical techniques to assess nanotoxicity did not account for potential interference of nanoparticles, and this number had not substantially improved in 2012. We provide guidance on avoiding and/or controlling for such interference to improve the accuracy of nanotoxicity assessments.

Widespread nanoparticle-assay interference: implications for nanotoxicity testing.

Directory of Open Access Journals (Sweden)

Kimberly J Ong

Full Text Available The evaluation of engineered nanomaterial safety has been hindered by conflicting reports demonstrating differential degrees of toxicity with the same nanoparticles. The unique properties of these materials increase the likelihood that they will interfere with analytical techniques, which may contribute to this phenomenon. We tested the potential for: 1 nanoparticle intrinsic fluorescence/absorbance, 2 interactions between nanoparticles and assay components, and 3 the effects of adding both nanoparticles and analytes to an assay, to interfere with the accurate assessment of toxicity. Silicon, cadmium selenide, titanium dioxide, and helical rosette nanotubes each affected at least one of the six assays tested, resulting in either substantial over- or under-estimations of toxicity. Simulation of realistic assay conditions revealed that interference could not be predicted solely by interactions between nanoparticles and assay components. Moreover, the nature and degree of interference cannot be predicted solely based on our current understanding of nanomaterial behaviour. A literature survey indicated that ca. 95% of papers from 2010 using biochemical techniques to assess nanotoxicity did not account for potential interference of nanoparticles, and this number had not substantially improved in 2012. We provide guidance on avoiding and/or controlling for such interference to improve the accuracy of nanotoxicity assessments.

Cross Layer Interference Management in Wireless Biomedical Networks

Directory of Open Access Journals (Sweden)

Emmanouil G. Spanakis

2014-04-01

Full Text Available Interference, in wireless networks, is a central phenomenon when multiple uncoordinated links share a common communication medium. The study of the interference channel was initiated by Shannon in 1961 and since then this problem has been thoroughly elaborated at the Information theoretic level but its characterization still remains an open issue. When multiple uncoordinated links share a common medium the effect of interference is a crucial limiting factor for network performance. In this work, using cross layer cooperative communication techniques, we study how to compensate interference in the context of wireless biomedical networks, where many links transferring biomedical or other health related data may be formed and suffer from all other interfering transmissions, to allow successful receptions and improve the overall network performance. We define the interference limited communication range to be the critical communication region around a receiver, with a number of surrounding interfering nodes, within which a successful communication link can be formed. Our results indicate that we can achieve more successful transmissions by adapting the transmission rate and power, to the path loss exponent, and the selected mode of the underline communication technique allowing interference mitigation and when possible lower power consumption and increase achievable transmission rates.

Quantum theory of two-photon wavepacket interference in a beamsplitter

International Nuclear Information System (INIS)

Wang, Kaige

2006-01-01

A general theory is derived for the interference of a two-photon wavepacket in a beamsplitter. The theory is presented in the Schroedinger picture so that the quantum nature of the two-photon interference is explicitly revealed. We find that the topological symmetry of the probability-amplitude spectrum of the two-photon wavepacket dominates the nature of the two-photon interference, which may be distinguished by the increase or decrease of the coincidence probability in the absence of interference. However, two-photon entanglement can be identified by the nature of the interference. We demonstrate the necessary and sufficient conditions for perfect two-photon interference. It is shown that a two-photon entangled state with an anti-symmetric spectrum passes through a 50/50 beamsplitter with perfect transparency. The theory provides us with a unified understanding of the various two-photon interference effects. (topical review)

Controlling quantum interference in phase space with amplitude

OpenAIRE

Xue, Yinghong; Li, Tingyu; Kasai, Katsuyuki; Okada-Shudo, Yoshiko; Watanabe, Masayoshi; Zhang, Yun

2017-01-01

We experimentally show a quantum interference in phase space by interrogating photon number probabilities (n?=?2, 3, and 4) of a displaced squeezed state, which is generated by an optical parametric amplifier and whose displacement is controlled by amplitude of injected coherent light. It is found that the probabilities exhibit oscillations of interference effect depending upon the amplitude of the controlling light field. This phenomenon is attributed to quantum interference in phase space a...

A New Design Approach to Game-Based learning

DEFF Research Database (Denmark)

Larsen, Lasse Juel

2012-01-01

to ground the student’s reason to learn. This paper proposes a different approach: using visualisation in immersive 3D worlds as both documentation of learning progress and as a reward system which motivates further learning. The overall design idea is to build a game based learning system from three......This paper puts forward a new design perspective for gamebased learning. The general idea is to abandon the long sought-after dream of designing a closed learning system, where students in both primary and secondary school could learn – without the interference of teachers – whatever subject......-based learning system, but will also confront aspects of modern learning theory, especially the notion of reference between the content of an assignment and the reality with which it should or could be connected (situated learning). The second idea promotes a way of tackling the common experience of the average...

Research on machine learning framework based on random forest algorithm

Science.gov (United States)

Ren, Qiong; Cheng, Hui; Han, Hai

2017-03-01

With the continuous development of machine learning, industry and academia have released a lot of machine learning frameworks based on distributed computing platform, and have been widely used. However, the existing framework of machine learning is limited by the limitations of machine learning algorithm itself, such as the choice of parameters and the interference of noises, the high using threshold and so on. This paper introduces the research background of machine learning framework, and combined with the commonly used random forest algorithm in machine learning classification algorithm, puts forward the research objectives and content, proposes an improved adaptive random forest algorithm (referred to as ARF), and on the basis of ARF, designs and implements the machine learning framework.

Generalized quantum interference of correlated photon pairs

Science.gov (United States)

Kim, Heonoh; Lee, Sang Min; Moon, Han Seb

2015-01-01

Superposition and indistinguishablility between probability amplitudes have played an essential role in observing quantum interference effects of correlated photons. The Hong-Ou-Mandel interference and interferences of the path-entangled photon number state are of special interest in the field of quantum information technologies. However, a fully generalized two-photon quantum interferometric scheme accounting for the Hong-Ou-Mandel scheme and path-entangled photon number states has not yet been proposed. Here we report the experimental demonstrations of the generalized two-photon interferometry with both the interferometric properties of the Hong-Ou-Mandel effect and the fully unfolded version of the path-entangled photon number state using photon-pair sources, which are independently generated by spontaneous parametric down-conversion. Our experimental scheme explains two-photon interference fringes revealing single- and two-photon coherence properties in a single interferometer setup. Using the proposed interferometric measurement, it is possible to directly estimate the joint spectral intensity of a photon pair source. PMID:25951143

Motor sequence learning occurs despite disrupted visual and proprioceptive feedback

Directory of Open Access Journals (Sweden)

Boyd Lara A

2008-07-01

Full Text Available Abstract Background Recent work has demonstrated the importance of proprioception for the development of internal representations of the forces encountered during a task. Evidence also exists for a significant role for proprioception in the execution of sequential movements. However, little work has explored the role of proprioceptive sensation during the learning of continuous movement sequences. Here, we report that the repeated segment of a continuous tracking task can be learned despite peripherally altered arm proprioception and severely restricted visual feedback regarding motor output. Methods Healthy adults practiced a continuous tracking task over 2 days. Half of the participants experienced vibration that altered proprioception of shoulder flexion/extension of the active tracking arm (experimental condition and half experienced vibration of the passive resting arm (control condition. Visual feedback was restricted for all participants. Retention testing was conducted on a separate day to assess motor learning. Results Regardless of vibration condition, participants learned the repeated segment demonstrated by significant improvements in accuracy for tracking repeated as compared to random continuous movement sequences. Conclusion These results suggest that with practice, participants were able to use residual afferent information to overcome initial interference of tracking ability related to altered proprioception and restricted visual feedback to learn a continuous motor sequence. Motor learning occurred despite an initial interference of tracking noted during acquisition practice.

Incorporating rapid neocortical learning of new schema-consistent information into complementary learning systems theory.

Science.gov (United States)

McClelland, James L

2013-11-01

The complementary learning systems theory of the roles of hippocampus and neocortex (McClelland, McNaughton, & O'Reilly, 1995) holds that the rapid integration of arbitrary new information into neocortical structures is avoided to prevent catastrophic interference with structured knowledge representations stored in synaptic connections among neocortical neurons. Recent studies (Tse et al., 2007, 2011) showed that neocortical circuits can rapidly acquire new associations that are consistent with prior knowledge. The findings challenge the complementary learning systems theory as previously presented. However, new simulations extending those reported in McClelland et al. (1995) show that new information that is consistent with knowledge previously acquired by a putatively cortexlike artificial neural network can be learned rapidly and without interfering with existing knowledge; it is when inconsistent new knowledge is acquired quickly that catastrophic interference ensues. Several important features of the findings of Tse et al. (2007, 2011) are captured in these simulations, indicating that the neural network model used in McClelland et al. has characteristics in common with neocortical learning mechanisms. An additional simulation generalizes beyond the network model previously used, showing how the rate of change of cortical connections can depend on prior knowledge in an arguably more biologically plausible network architecture. In sum, the findings of Tse et al. are fully consistent with the idea that hippocampus and neocortex are complementary learning systems. Taken together, these findings and the simulations reported here advance our knowledge by bringing out the role of consistency of new experience with existing knowledge and demonstrating that the rate of change of connections in real and artificial neural networks can be strongly prior-knowledge dependent. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Structural constraints on organizational and interorganizational learning in the restaurant sector

DEFF Research Database (Denmark)

Hjalager, Anne Mette

1998-01-01

Examines the rates of mortality, survival, and entrepreneurship in the Danish restaurant sector, and demonstrates a considerable turbulence in the sector over the period 1980-1993. Opportunities for organizational learning are enhanced by size as well as age. However, surprisingly, survival...... is not clearly related to managerial capacity, nor is affiliation with other restaurants an important factor for survival. The study indicates that learning in restaurants is decisively embedded in processes and technologies rather than in relations between human beings....

How to be proactive about interference: lessons from animal memory.

Science.gov (United States)

Wright, Anthony A; Katz, Jeffrey S; Ma, Wei Ji

2012-05-01

Processes of proactive interference were explored using the pigeon as a model system of memory. This study shows that proactive interference extends back in time at least 16 trials (and as many minutes), revealing a continuum of interference and providing a framework for studying memory. Pigeons were tested in a delayed same/different task containing trial-unique pictures. On interference trials, sample pictures from previous trials reappeared as test pictures on different trials. Proactive-interference functions showed greatest interference from the most recent trial and with the longer of two delays (10 s vs. 1 s). These interference functions are accounted for by a time-estimation model based on signal detection theory. The model predicts that accuracy at test is determined solely by the ratio of the elapsed time since the offset of the current-trial sample to the elapsed time since the offset of the interfering sample. Implications for comparing memory of different species and different types of memory (e.g., familiarity vs. recollection) are discussed.

Complete destructive interference of partially coherent fields

NARCIS (Netherlands)

Gbur, G.J.; Visser, T.D.; Wolf, E.

2004-01-01

A three-point source model is used to study the interference of wavefields which are mutually partially coherent. It is shown that complete destructive interference of the fields is possible in such a "three-pinhole interferometer" even if the sources are not fully coherent with respect to each

STRUCTURE FORMATION PRINCIPLES OF INTERFERENCE BEAM SPLITTERS

Directory of Open Access Journals (Sweden)

L. A. Gubanova

2012-01-01

Full Text Available The methodology of interference beam splitters construction, formed by symmetric cells of dielectric layers is considered. The methodology of short-wave and long-wave interference beam splitters formation is given. The impact analysis of symmetric cells number and their structure on output parameters is considered.

Laser Interference Lithography

NARCIS (Netherlands)

van Wolferen, Hendricus A.G.M.; Abelmann, Leon; Hennessy, Theodore C.

In this chapter we explain how submicron gratings can be prepared by Laser Interference Lithography (LIL). In this maskless lithography technique, the standing wave pattern that exists at the intersection of two coherent laser beams is used to expose a photosensitive layer. We show how to build the

Amount of kinematic feedback affects learning of speech motor skills.

Science.gov (United States)

Ballard, Kirrie J; Smith, Heather D; Paramatmuni, Divija; McCabe, Patricia; Theodoros, Deborah G; Murdoch, Bruce E

2012-01-01

Knowledge of Performance (KP) feedback, such as biofeedback or kinematic feedback, is used to provide information on the nature and quality of movement responses for the purpose of guiding active learning or rehabilitation of motor skills. It has been proposed that KP feedback may interfere with long-term learning when provided throughout training. Here, twelve healthy English-speaking adults were trained to produce a trilled Russian [r] in words with KP kinematic feedback using electropalatography (EPG) and without KP (noKP). Five one-hour training sessions were provided over one week with testing pretraining and one day and one week posttraining. No group differences were found at pretraining or one day post training for production accuracy. A group by time interaction supported the hypothesis that providing kinematic feedback continually during skill acquisition interferes with retention.

An interference model of visual working memory.

Science.gov (United States)

Oberauer, Klaus; Lin, Hsuan-Yu

2017-01-01

The article introduces an interference model of working memory for information in a continuous similarity space, such as the features of visual objects. The model incorporates the following assumptions: (a) Probability of retrieval is determined by the relative activation of each retrieval candidate at the time of retrieval; (b) activation comes from 3 sources in memory: cue-based retrieval using context cues, context-independent memory for relevant contents, and noise; (c) 1 memory object and its context can be held in the focus of attention, where it is represented with higher precision, and partly shielded against interference. The model was fit to data from 4 continuous-reproduction experiments testing working memory for colors or orientations. The experiments involved variations of set size, kind of context cues, precueing, and retro-cueing of the to-be-tested item. The interference model fit the data better than 2 competing models, the Slot-Averaging model and the Variable-Precision resource model. The interference model also fared well in comparison to several new models incorporating alternative theoretical assumptions. The experiments confirm 3 novel predictions of the interference model: (a) Nontargets intrude in recall to the extent that they are close to the target in context space; (b) similarity between target and nontarget features improves recall, and (c) precueing-but not retro-cueing-the target substantially reduces the set-size effect. The success of the interference model shows that working memory for continuous visual information works according to the same principles as working memory for more discrete (e.g., verbal) contents. Data and model codes are available at https://osf.io/wgqd5/. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Acoustic and semantic interference effects in words and pictures.

Science.gov (United States)

Dhawan, M; Pellegrino, J W

1977-05-01

Interference effects for pictures and words were investigated using a probe-recall task. Word stimuli showed acoustic interference effects for items at the end of the list and semantic interference effects for items at the beginning of the list, similar to results of Kintsch and Buschke (1969). Picture stimuli showed large semantic interference effects at all list positions with smaller acoustic interference effects. The results were related to latency data on picture-word processing and interpreted in terms of the differential order, probability, and/or speed of access to acoustic and semantic levels of processing. A levels of processing explanation of picture-word retention differences was related to dual coding theory. Both theoretical positions converge on an explanation of picture-word retention differences as a function of the relative capacity for semantic or associative processing.

Non-Interference and Erasure Policies for Java Card Bytecode

DEFF Research Database (Denmark)

Hansen, René Rydhof; Probst, Christian W.

2006-01-01

Non-interference is the property of a program not to leak any secret information. In this paper we propose a notion of non-interference for an abstract version of the Java Card bytecode language. Furthermore an information-flow analysis for verifying non-interference is developed and proved sound...... that confidential information is unavailable after a certain point---and that this unavailability is enforced by the system. This is a crucial requirement for systems like e-commerce or e-voting....... and correct with respect to the formal semantics of the language. The information-flow analysis can automatically verify the absence of leaks in a program, thus proving non-interference. Based on the definition of non-interference we propose a notion of simple erasure policies. These allow to statically check...

Complete hazard ranking to analyze right-censored data: An ALS survival study.

Directory of Open Access Journals (Sweden)

Zhengnan Huang

2017-12-01

Full Text Available Survival analysis represents an important outcome measure in clinical research and clinical trials; further, survival ranking may offer additional advantages in clinical trials. In this study, we developed GuanRank, a non-parametric ranking-based technique to transform patients' survival data into a linear space of hazard ranks. The transformation enables the utilization of machine learning base-learners including Gaussian process regression, Lasso, and random forest on survival data. The method was submitted to the DREAM Amyotrophic Lateral Sclerosis (ALS Stratification Challenge. Ranked first place, the model gave more accurate ranking predictions on the PRO-ACT ALS dataset in comparison to Cox proportional hazard model. By utilizing right-censored data in its training process, the method demonstrated its state-of-the-art predictive power in ALS survival ranking. Its feature selection identified multiple important factors, some of which conflicts with previous studies.

Interference of an array of independent Bose-Einstein condensates

International Nuclear Information System (INIS)

Hadzibabic, Zoran; Stock, Sabine; Battelier, Baptiste; Bretin, Vincent; Dalibard, Jean

2004-01-01

We have observed high-contrast matter wave interference between 30 Bose-Einstein condensates with uncorrelated phases. Interferences were observed after the independent condensates were released from a one-dimensional optical lattice and allowed to overlap. This phenomenon is explained with a simple theoretical model, which generalizes the analysis of the interference of two condensates

Resonance interference method in lattice physics code stream

International Nuclear Information System (INIS)

Choi, Sooyoung; Khassenov, Azamat; Lee, Deokjung

2015-01-01

Newly developed resonance interference model is implemented in the lattice physics code STREAM, and the model shows a significant improvement in computing accurate eigenvalues. Equivalence theory is widely used in production calculations to generate the effective multigroup (MG) cross-sections (XS) for commercial reactors. Although a lot of methods have been developed to enhance the accuracy in computing effective XSs, the current resonance treatment methods still do not have a clear resonance interference model. The conventional resonance interference model simply adds the absorption XSs of resonance isotopes to the background XS. However, the conventional models show non-negligible errors in computing effective XSs and eigenvalues. In this paper, a resonance interference factor (RIF) library method is proposed. This method interpolates the RIFs in a pre-generated RIF library and corrects the effective XS, rather than solving the time consuming slowing down calculation. The RIF library method is verified for homogeneous and heterogeneous problems. The verification results using the proposed method show significant improvements of accuracy in treating the interference effect. (author)

Survival and sustainability. Environmental concerns in the 21st century

Energy Technology Data Exchange (ETDEWEB)

Goekcekus, Hueseyin; Tuerker, Umut [Near East Univ., Nicosia, North Cyprus (Turkey). Dept. of Civil Engineering; LaMoreaux, James W. (eds.) [P.E. LaMoreaux and Associates, Tuscaloosa, AL (United States)

2011-07-01

The International Conference on Environment: Survival and Sustainability, held at the Near East University, Nicosia, Northern Cyprus 19-24 February 2007, dealt with environmental threats and proposed solutions at all scales. The 21 themes addressed by the conference fell into four broad categories; Threats to Survival and Sustainability; Technological Advances towards Survival and Sustainability; Activities and Tools for Social Change; Defining Goals for Sustainable Societies. Activities and tools that move the society towards greater sustainability were emphasized at the conference. These included environmental law and ethics, environmental knowledge, technology and information systems, media, environmental awareness, education and lifelong learning, the use of literature for environmental awareness, the green factor in politics, international relations and environmental organizations. The breadth of the issues addressed at the conference made clear the need for greatly increased interdisciplinary and international collaboration the survival and sustainability concept. The exchanges at the conference represent a step in this direction. (orig.)

Auditory verbal learning in drug-free Ecstasy polydrug users.

Science.gov (United States)

Fox, H. C.; Toplis, A. S.; Turner, J. J. D.; Parrott, A. C.

2001-12-01

Drug-free Ecstasy polydrug users have shown impairment on tasks of verbal working memory and memory span. Current research aims to investigate how these deficits may affect the learning of verbal material by administration of the Auditory Verbal Learning Task (AVLT) (Rey, 1964). The task provides a learning curve by assessing immediate memory span over multiple trials. Learning strategies are further analysed by tendencies to confabulate as well as demonstrate either proactive or retroactive interference elicited by a novel 'distractor' list. Three groups completed the task: two groups of 14 Ecstasy users (short- and long-term) and one group of 14 polydrug controls. Compared with controls both Ecstasy groups recalled significantly fewer words and made more confabulation errors on the initial three recall trials as well as a delayed recall trial. Long-term users demonstrated increased confabulation on the initial trials and the novel 'distractor7' trial, compared with short-term users. Only following repeated presentations were both short- and long-term users shown to perform at control levels. As such, deficits in verbal learning may be more related to storage and/or retrieval problems than problems associated with capacity per se. No interference errors were demonstrated by either of the Ecstasy groups. However, a high level of intrusion errors may indicate selective working memory problems associated with longer-term use of the drug. Copyright 2001 John Wiley & Sons, Ltd.

Imperfect generalized transmit beamforming with co-channel interference cancelation

KAUST Repository

Radaydeh, Redha Mahmoud Mesleh

2010-10-01

The performance of a generalized single-stream transmit beamforming scheme employing receive co-channel interference -steering algorithms in slowly varying and flat fading channels is analyzed. The impact of imperfect prediction of channel state information (CSI) for the desired user spatially uncorrelated transmit channels is considered. Both dominant interference cancelation and adaptive arbitrary interference cancelation algorithms for closely spaced receive antennas are used. The impact of outdated statistical ordering of the interferers instantaneous powers on the effectiveness of dominant interference cancelation is investigated against the less complex adaptive arbitrary cancelation scheme. For the system models described above, new exact formulas for the statistics of combined signal-to-interference-plus-noise ratio (SINR) are derived, from which results for conventional maximum ratio transmission (MRT) and best transmit channel selection schemes can be deduced as limiting cases. The results presented herein can be used to obtain quantitative measure for various performance metrics, and in addition to investigate the performance-complexity tradeoff for different multiple-antenna system models. © 2010 IEEE.

Role of dressed-state interference in electromagnetically induced transparency

International Nuclear Information System (INIS)

Khan, Sumanta; Bharti, Vineet; Natarajan, Vasant

2016-01-01

Highlights: • Role of dressed-state interference is investigated on lambda, ladder and vee type EIT systems. • The effect of interference decreases with increasing Rabi frequency of the control laser. • Dressed-state interference plays an important role in lambda system and a negligible role in ladder and vee systems. - Abstract: Electromagnetically induced transparency (EIT) in three-level systems uses a strong control laser on one transition to modify the absorption of a weak probe laser on a second transition. The control laser creates dressed states whose decay pathways show interference. We study the role of dressed-state interference in causing EIT in the three types of three-level systems—lambda (Λ), ladder (Ξ), and vee (V). In order to get realistic values for the linewidths of the energy levels involved, we consider appropriate hyperfine levels of "8"7Rb. For such realistic systems, we find that dressed-state interference causes probe absorption—given by the imaginary part of the susceptibility—to go to zero in a Λ system, but plays a negligible role in Ξ and V systems.

Role of dressed-state interference in electromagnetically induced transparency

Energy Technology Data Exchange (ETDEWEB)

Khan, Sumanta; Bharti, Vineet; Natarajan, Vasant

2016-12-16

Highlights: • Role of dressed-state interference is investigated on lambda, ladder and vee type EIT systems. • The effect of interference decreases with increasing Rabi frequency of the control laser. • Dressed-state interference plays an important role in lambda system and a negligible role in ladder and vee systems. - Abstract: Electromagnetically induced transparency (EIT) in three-level systems uses a strong control laser on one transition to modify the absorption of a weak probe laser on a second transition. The control laser creates dressed states whose decay pathways show interference. We study the role of dressed-state interference in causing EIT in the three types of three-level systems—lambda (Λ), ladder (Ξ), and vee (V). In order to get realistic values for the linewidths of the energy levels involved, we consider appropriate hyperfine levels of {sup 87}Rb. For such realistic systems, we find that dressed-state interference causes probe absorption—given by the imaginary part of the susceptibility—to go to zero in a Λ system, but plays a negligible role in Ξ and V systems.

Schema benefit vs. proactive interference: Contradicting behavioral outcomes and coexisting neural patterns.

Science.gov (United States)

Oren, Noga; Shapira-Lichter, Irit; Lerner, Yulia; Tarrasch, Ricardo; Hendler, Talma; Giladi, Nir; Ash, Elissa L

2017-09-01

Prior knowledge can either assist or hinder the ability to learn new information. These contradicting behavioral outcomes, referred to as schema benefit and proactive interference respectively, have been studied separately. Here we examined whether the known neural correlates of each process coexist, and how they are influenced by attentional loading and aging. To this end we used an fMRI task that affected both processes simultaneously by presenting pairs of related short movies in succession. The first movie of each pair provided context for the second movie, which could evoke schema benefit and/or proactive interference. Inclusion of an easy or hard secondary task performed during encoding of the movies, as well as testing both younger (22-35y) and older (65-79y) adults, allowed examining the effect of attentional load and older age on the neural patterns associated with context. Analyses focused on three predefined regions and examined how their inter-subject correlation (inter-SC) and functional connectivity (FC) with the hippocampi changed between the first and second movie. The results in the medial prefrontal cortex (mPFC) and posterior cingulate cortex (PCC) matched and expanded previous findings: higher inter-SC and lower FC were observed during the second compared to the first movie; yet the differentiation between the first and second movies in these regions was attenuated under high attentional load, pointing to dependency on attentional resources. Instead, at high load there was a significant context effect in the FC of the left ventrolateral prefrontal cortex (vlPFC), and greater FC in the second movie was related to greater proactive interference. Further, older adults showed context effect in the PCC and vlPFC. Intriguingly, older adults with inter-SC mPFC patterns similar to younger adults exhibited schema benefit in our task, while those with inter-SC PCC patterns similar to younger adults showed proactive interference in an independent task. The

Application and research of artificial water mist on photoelectric interference

Science.gov (United States)

He, Yuejun; Ren, Baolin

2018-04-01

Water mist is a new type of photoelectric interfering material. It can exert a strong interference and shielding effect on infrared light, laser and radar wave through scattering, reflection, refraction and absorption. Based on this, this paper illustrates the application of an artificial high pressure water mist technology in infrared interference system. First, the operating principle of the infrared interference system is introduced. Next, the design principle of self-excited rotary vortex nozzle, the key part of the system, is elaborated. Then, the calculation of the main control parameters of the system is clarified. In the end, the paper verifies interference and shielding effect of the system by experiment. Experiment shows that the interference system can significantly reduce infrared signature of the target, featuring excellent infrared interference performance and high practical value.

Interference and the Law of Energy Conservation

Science.gov (United States)

Drosd, Robert; Minkin, Leonid; Shapovalov, Alexander S.

2014-01-01

Introductory physics textbooks consider interference to be a process of redistribution of energy from the wave sources in the surrounding space resulting in constructive and destructive interferences. As one can expect, the total energy flux is conserved. However, one case of apparent non-conservation energy attracts great attention. Imagine that…

Adaptive Landmark-Based Navigation System Using Learning Techniques

DEFF Research Database (Denmark)

Zeidan, Bassel; Dasgupta, Sakyasingha; Wörgötter, Florentin

2014-01-01

The goal-directed navigational ability of animals is an essential prerequisite for them to survive. They can learn to navigate to a distal goal in a complex environment. During this long-distance navigation, they exploit environmental features, like landmarks, to guide them towards their goal. In...... hexapod robots. As a result, it allows the robots to successfully learn to navigate to distal goals in complex environments.......The goal-directed navigational ability of animals is an essential prerequisite for them to survive. They can learn to navigate to a distal goal in a complex environment. During this long-distance navigation, they exploit environmental features, like landmarks, to guide them towards their goal....... Inspired by this, we develop an adaptive landmark-based navigation system based on sequential reinforcement learning. In addition, correlation-based learning is also integrated into the system to improve learning performance. The proposed system has been applied to simulated simple wheeled and more complex...

Improper Gaussian Signaling in Interference-Limited Systems

KAUST Repository

Gaafar, Mohamed

2016-05-01

In the last decade, wireless applications have witnessed a tremendous growth. This can be envisioned in the surge of smart devices which became almost in everyone\\'s possession, demand for high speed connection and the internet of things (IoT) along with its enabling technologies. Hence, the multiuser interference became the main limiting factor in wireless communications. Moreover, just like diamonds and emeralds, the electromagnetic spectrum is limited and precious. Therefore, the high data rate application may not be satisfied by our current technologies. In order to solve this spectrum scarcity problem, researchers have steered their focus to develop new techniques such as cognitive radio (CR) and in-band full-duplex (FD). However, these systems suffer from the interference problem that can dramatically impede their quality-of-service (QoS). Therefore, investigating communication techniques/systems that can relieve the interference adverse signature becomes imperative. Improper Gaussian signaling (IGS) has been recently shown to outperform the traditional proper Gaussian signaling (PGS) in several interference-limited systems. In this thesis, we use IGS in order to mitigate the interference issue in three different communication settings. IGS has the ability to control the interference signal dimension, and hence, it can be considered as one form of interference alignment. In the first part, we investigate an underlay CR system with in-band FD primary users (PUs) and one-way communication for the secondary user (SU). IGS is employed to alleviate the interference introduced by the SU on the PUs. First, we derive a closed form expression and an upper bound for the SU and PUs outage probabilities, respectively. Second, we optimize the SU signal parameters, represented in its power and the circularity coefficient, to achieve the design objectives of the SU while satisfying certain QoS constraints for the PU under instantaneous, average and partial channel state

An ensemble machine learning approach to predict survival in breast cancer.

Science.gov (United States)

Djebbari, Amira; Liu, Ziying; Phan, Sieu; Famili, Fazel

2008-01-01

Current breast cancer predictive signatures are not unique. Can we use this fact to our advantage to improve prediction? From the machine learning perspective, it is well known that combining multiple classifiers can improve classification performance. We propose an ensemble machine learning approach which consists of choosing feature subsets and learning predictive models from them. We then combine models based on certain model fusion criteria and we also introduce a tuning parameter to control sensitivity. Our method significantly improves classification performance with a particular emphasis on sensitivity which is critical to avoid misclassifying poor prognosis patients as good prognosis.

Parton showers with quantum interference

CERN Document Server

Nagy, Zoltan

2007-01-01

We specify recursive equations that could be used to generate a lowest order parton shower for hard scattering in hadron-hadron collisions. The formalism is based on the factorization soft and collinear interactions from relatively harder interactions in QCD amplitudes. It incorporates quantum interference between different amplitudes in those cases in which the interference diagrams have leading soft or collinear singularities. It incorporates the color and spin information carried by partons emerging from a hard interaction. One motivation for this work is to have a method that can naturally cooperate with next-to-leading order calculations.

Parton showers with quantum interference

International Nuclear Information System (INIS)

Nagy, Zoltan; Soper, Davison E.

2007-01-01

We specify recursive equations that could be used to generate a lowest order parton shower for hard scattering in hadron-hadron collisions. The formalism is based on the factorization soft and collinear interactions from relatively harder interactions in QCD amplitudes. It incorporates quantum interference between different amplitudes in those cases in which the interference diagrams have leading soft or collinear singularities. It incorporates the color and spin information carried by partons emerging from a hard interaction. One motivation for this work is to have a method that can naturally cooperate with next-to-leading order calculations

Mitigating Inter-Network Interference in LoRa Networks

OpenAIRE

Voigt, Thiemo; Bor, Martin; Roedig, Utz; Alonso, Juan

2017-01-01

Long Range (LoRa) is a popular technology used to construct Low-Power Wide-Area Network (LPWAN) networks. Given the popularity of LoRa it is likely that multiple independent LoRa networks are deployed in close proximity. In this situation, neighbouring networks interfere and methods have to be found to combat this interference. In this paper we investigate the use of directional antennae and the use of multiple base stations as methods of dealing with inter-network interference. Directional a...

Introduction of the Space Shuttle Columbia Accident, Investigation Details, Findings and Crew Survival Investigation Report

Science.gov (United States)

Chandler, Michael

2010-01-01

As the Space Shuttle Program comes to an end, it is important that the lessons learned from the Columbia accident be captured and understood by those who will be developing future aerospace programs and supporting current programs. Aeromedical lessons learned from the Accident were presented at AsMA in 2005. This Panel will update that information, closeout the lessons learned, provide additional information on the accident and provide suggestions for the future. To set the stage, an overview of the accident is required. The Space Shuttle Columbia was returning to Earth with a crew of seven astronauts on 1Feb, 2003. It disintegrated along a track extending from California to Louisiana and observers along part of the track filmed the breakup of Columbia. Debris was recovered from Littlefield, Texas to Fort Polk, Louisiana, along a 567 statute mile track; the largest ever recorded debris field. The Columbia Accident Investigation Board (CAIB) concluded its investigation in August 2003, and released their findings in a report published in February 2004. NASA recognized the importance of capturing the lessons learned from the loss of Columbia and her crew and the Space Shuttle Program managers commissioned the Spacecraft Crew Survival Integrated Investigation Team (SCSIIT) to accomplish this. Their task was to perform a comprehensive analysis of the accident, focusing on factors and events affecting crew survival, and to develop recommendations for improving crew survival, including the design features, equipment, training and procedures intended to protect the crew. NASA released the Columbia Crew Survival Investigation Report in December 2008. Key personnel have been assembled to give you an overview of the Space Shuttle Columbia accident, the medical response, the medico-legal issues, the SCSIIT findings and recommendations and future NASA flight surgeon spacecraft accident response training. Educational Objectives: Set the stage for the Panel to address the

Neuronal Rac1 Is Required for Learning-Evoked Neurogenesis

Science.gov (United States)

Anderson, Matthew P.; Freewoman, Julia; Cord, Branden; Babu, Harish; Brakebusch, Cord

2013-01-01

Hippocampus-dependent learning and memory relies on synaptic plasticity as well as network adaptations provided by the addition of adult-born neurons. We have previously shown that activity-induced intracellular signaling through the Rho family small GTPase Rac1 is necessary in forebrain projection neurons for normal synaptic plasticity in vivo, and here we show that selective loss of neuronal Rac1 also impairs the learning-evoked increase in neurogenesis in the adult mouse hippocampus. Earlier work has indicated that experience elevates the abundance of adult-born neurons in the hippocampus primarily by enhancing the survival of neurons produced just before the learning event. Loss of Rac1 in mature projection neurons did reduce learning-evoked neurogenesis but, contrary to our expectations, these effects were not mediated by altering the survival of young neurons in the hippocampus. Instead, loss of neuronal Rac1 activation selectively impaired a learning-evoked increase in the proliferation and accumulation of neural precursors generated during the learning event itself. This indicates that experience-induced alterations in neurogenesis can be mechanistically resolved into two effects: (1) the well documented but Rac1-independent signaling cascade that enhances the survival of young postmitotic neurons; and (2) a previously unrecognized Rac1-dependent signaling cascade that stimulates the proliferative production and retention of new neurons generated during learning itself. PMID:23884931

Interference-robust Air Interface for 5G Small Cells

DEFF Research Database (Denmark)

Tavares, Fernando Menezes Leitão

the existing wireless network infrastructure to the limit. Mobile network operators must invest in network expansion to deal with this problem, but the predicted network requirements show that a new Radio Access Technology (RAT) standard will be fundamental to reach the future target performance. This new 5th...... to the fundamental role of inter-cell interference in this type of networks, the inter-cell interference problem must be addressed since the beginning of the design of the new standard. This Ph.D. thesis deals with the design of an interference-robust air interface for 5G small cell networks. The interference...

The proximate memory mechanism underlying the survival-processing effect: richness of encoding or interactive imagery?

Science.gov (United States)

Kroneisen, Meike; Erdfelder, Edgar; Buchner, Axel

2013-01-01

Nairne and collaborators showed that assessing the relevance of words in the context of an imagined survival scenario boosts memory for these words. Although this survival-processing advantage has attracted a considerable amount of research, little is known about the proximate memory mechanism mediating this effect. Recently, Kroneisen and Erdfelder (2011) argued that it is not survival processing itself that facilitates recall but rather the richness and distinctiveness of encoding that is triggered by the survival-processing task. Alternatively, however, it is also conceivable that survival processing fosters interactive imagery, a process known to improve associative learning. To test these explanations we compared relevance-rating and interactive imagery tasks for survival and control scenarios. Results show that the survival advantage replicates in the relevance-rating condition but vanishes in the interactive imagery condition. This refutes the interactive imagery explanation and corroborates the richness-of-encoding hypothesis of the survival-processing effect.

Electron quantum interferences and universal conductance fluctuations

International Nuclear Information System (INIS)

Benoit, A.; Pichard, J.L.

1988-05-01

Quantum interferences yield corrections to the classical ohmic behaviour predicted by Boltzmann theory in electronic transport: for instance the well-known ''weak localization'' effects. Furthermore, very recently, quantum interference effects have been proved to be responsible for statistically different phenomena, associated with Universal Conductance Fluctuations and observed on very small devices [fr

The Compensation Method of Vehicle Magnetic Interference for the Magnetic Gradiometer

OpenAIRE

Lv, Junwei; Yu, Zhentao; Huang, Jingli; Zhou, Jing

2013-01-01

The magnetic interference of vehicle imposes a strong influence on the magnetic gradiometer. Based on the mechanism of the vehicle magnetic interference, we firstly use the difference algorithm of the magnetic gradient tensor to fuse the magnetic interference of each vector magnetometer and establish a mathematical model of vehicle magnetic interference for the magnetic gradiometer. Next, we propose a compensation method for the vehicle magnetic interference and a recognition method for the e...

Cooperation for Interference Management: A GDoF Perspective

KAUST Repository

Gherekhloo, Soheil; Chaaban, Anas; Sezgin, Aydin

2016-01-01

The impact of cooperation on interference management is investigated by studying an elemental wireless network, the so-called symmetric interference relay channel (IRC), from a generalized degrees of freedom (GDoF) perspective. This is motivated

Interference-free ultrasound imaging during HIFU therapy, using software tools

Science.gov (United States)

Vaezy, Shahram (Inventor); Held, Robert (Inventor); Sikdar, Siddhartha (Inventor); Managuli, Ravi (Inventor); Zderic, Vesna (Inventor)

2010-01-01

Disclosed herein is a method for obtaining a composite interference-free ultrasound image when non-imaging ultrasound waves would otherwise interfere with ultrasound imaging. A conventional ultrasound imaging system is used to collect frames of ultrasound image data in the presence of non-imaging ultrasound waves, such as high-intensity focused ultrasound (HIFU). The frames are directed to a processor that analyzes the frames to identify portions of the frame that are interference-free. Interference-free portions of a plurality of different ultrasound image frames are combined to generate a single composite interference-free ultrasound image that is displayed to a user. In this approach, a frequency of the non-imaging ultrasound waves is offset relative to a frequency of the ultrasound imaging waves, such that the interference introduced by the non-imaging ultrasound waves appears in a different portion of the frames.

Conditions of Practice in Perceptual Skill Learning

Science.gov (United States)

Memmert, D.; Hagemann, N.; Althoetmar, R.; Geppert, S.; Seiler, D.

2009-01-01

This study uses three experiments with different kinds of training conditions to investigate the "easy-to-hard" principle, context interference conditions, and feedback effects for learning anticipatory skills in badminton. Experiment 1 (N = 60) showed that a training program that gradually increases the difficulty level has no advantage over the…

Interferences in place attachment: implications for wilderness

Science.gov (United States)

Erin K. Sharpe; Alan W. Ewert

2000-01-01

Previous research on place attachment has tended to focus on attachment formation, with relatively little attention given to factors that disrupt or interfere with formed place attachments. Interferences to attachments are a worthy research area for two reasons: 1) The factors of place attachment are often more salient when being disrupted, and 2) place attachment...

Spin wave scattering and interference in ferromagnetic cross

Energy Technology Data Exchange (ETDEWEB)

Nanayakkara, Kasuni; Kozhanov, Alexander [Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303 (United States); Center for Nano Optics, Georgia State University, Atlanta, Georgia 30303 (United States); Jacob, Ajey P. [Exploratory Research Device and Integration, GLOBALFOUNDRIES, Albany, New York 12203 (United States)

2015-10-28

Magnetostatic spin wave scattering and interference across a CoTaZr ferromagnetic spin wave waveguide cross junction were investigated experimentally and by micromagnetic simulations. It is observed that the phase of the scattered waves is dependent on the wavelength, geometry of the junction, and scattering direction. It is found that destructive and constructive interference of the spin waves generates switching characteristics modulated by the input phase of the spin waves. Micromagnetic simulations are used to analyze experimental data and simulate the spin wave scattering and interference.

Protein kinase activity of phosphoinositide 3-kinase regulates cytokine-dependent cell survival.

Directory of Open Access Journals (Sweden)

Daniel Thomas

Full Text Available The dual specificity protein/lipid kinase, phosphoinositide 3-kinase (PI3K, promotes growth factor-mediated cell survival and is frequently deregulated in cancer. However, in contrast to canonical lipid-kinase functions, the role of PI3K protein kinase activity in regulating cell survival is unknown. We have employed a novel approach to purify and pharmacologically profile protein kinases from primary human acute myeloid leukemia (AML cells that phosphorylate serine residues in the cytoplasmic portion of cytokine receptors to promote hemopoietic cell survival. We have isolated a kinase activity that is able to directly phosphorylate Ser585 in the cytoplasmic domain of the interleukin 3 (IL-3 and granulocyte macrophage colony stimulating factor (GM-CSF receptors and shown it to be PI3K. Physiological concentrations of cytokine in the picomolar range were sufficient for activating the protein kinase activity of PI3K leading to Ser585 phosphorylation and hemopoietic cell survival but did not activate PI3K lipid kinase signaling or promote proliferation. Blockade of PI3K lipid signaling by expression of the pleckstrin homology of Akt1 had no significant impact on the ability of picomolar concentrations of cytokine to promote hemopoietic cell survival. Furthermore, inducible expression of a mutant form of PI3K that is defective in lipid kinase activity but retains protein kinase activity was able to promote Ser585 phosphorylation and hemopoietic cell survival in the absence of cytokine. Blockade of p110α by RNA interference or multiple independent PI3K inhibitors not only blocked Ser585 phosphorylation in cytokine-dependent cells and primary human AML blasts, but also resulted in a block in survival signaling and cell death. Our findings demonstrate a new role for the protein kinase activity of PI3K in phosphorylating the cytoplasmic tail of the GM-CSF and IL-3 receptors to selectively regulate cell survival highlighting the importance of targeting

Spatial learning depends on both the addition and removal of new hippocampal neurons.

Directory of Open Access Journals (Sweden)

David Dupret

2007-08-01

Full Text Available The role of adult hippocampal neurogenesis in spatial learning remains a matter of debate. Here, we show that spatial learning modifies neurogenesis by inducing a cascade of events that resembles the selective stabilization process characterizing development. Learning promotes survival of relatively mature neurons, apoptosis of more immature cells, and finally, proliferation of neural precursors. These are three interrelated events mediating learning. Thus, blocking apoptosis impairs memory and inhibits learning-induced cell survival and cell proliferation. In conclusion, during learning, similar to the selective stabilization process, neuronal networks are sculpted by a tightly regulated selection and suppression of different populations of newly born neurons.

Towards quantum computation with multi-particle interference

Energy Technology Data Exchange (ETDEWEB)

Tamma, Vincenzo; Schleich, Wolfgang P. [Institut fuer Quantenphysik, Universitaet Ulm (Germany); Shih, Yanhua [Univ. of Maryland, Baltimore County, Baltimore, MD (Germany). Dept. of Physics

2012-07-01

One of the main challenges in quantum computation is the realization of entangled states with a large number of particles. We have experimentally demonstrated a novel factoring algorithm which relies only on optical multi-path interference and on the periodicity properties of Gauss sums with continuous arguments. An interesting implementation of such a method can, in principle, take advantage of matter-wave interferometers characterized by long-time evolution of a BEC in microgravity. A more recent approach to factorization aims to achieve an exponential speed-up without entanglement by exploiting multi-particle m-order interference. In this case, the basic requirement for quantum computation is interference of an exponentially large number of multi-particle amplitudes.

Continuous Correctness of Business Processes Against Process Interference

NARCIS (Netherlands)

van Beest, Nick; Bucur, Doina

2013-01-01

In distributed business process support environments, process interference from multiple stakeholders may cause erroneous process outcomes. Existing solutions to detect and correct interference at runtime employ formal verification and the automatic generation of intervention processes at runtime.

Interference-aware random beam selection for spectrum sharing systems

KAUST Repository

Abdallah, Mohamed M.

2012-09-01

Spectrum sharing systems have been introduced to alleviate the problem of spectrum scarcity by allowing secondary unlicensed networks to share the spectrum with primary licensed networks under acceptable interference levels to the primary users. In this paper, we develop interference-aware random beam selection schemes that provide enhanced throughput for the secondary link under the condition that the interference observed at the primary link is within a predetermined acceptable value. For a secondary transmitter equipped with multiple antennas, our schemes select a random beam, among a set of power- optimized orthogonal random beams, that maximizes the capacity of the secondary link while satisfying the interference constraint at the primary receiver for different levels of feedback information describing the interference level at the primary receiver. For the proposed schemes, we develop a statistical analysis for the signal-to-noise and interference ratio (SINR) statistics as well as the capacity of the secondary link. Finally, we present numerical results that study the effect of system parameters including number of beams and the maximum transmission power on the capacity of the secondary link attained using the proposed schemes. © 2012 IEEE.

No trade-off between learning speed and associative flexibility in bumblebees: a reversal learning test with multiple colonies.

Directory of Open Access Journals (Sweden)

Nigel E Raine

Full Text Available Potential trade-offs between learning speed and memory-related performance could be important factors in the evolution of learning. Here, we test whether rapid learning interferes with the acquisition of new information using a reversal learning paradigm. Bumblebees (Bombus terrestris were trained to associate yellow with a floral reward. Subsequently the association between colour and reward was reversed, meaning bees then had to learn to visit blue flowers. We demonstrate that individuals that were fast to learn yellow as a predictor of reward were also quick to reverse this association. Furthermore, overnight memory retention tests suggest that faster learning individuals are also better at retaining previously learned information. There is also an effect of relatedness: colonies whose workers were fast to learn the association between yellow and reward also reversed this association rapidly. These results are inconsistent with a trade-off between learning speed and the reversal of a previously made association. On the contrary, they suggest that differences in learning performance and cognitive (behavioural flexibility could reflect more general differences in colony learning ability. Hence, this study provides additional evidence to support the idea that rapid learning and behavioural flexibility have adaptive value.

INTERFERENCE FRINGES OF SOLAR ACOUSTIC WAVES AROUND SUNSPOTS

Energy Technology Data Exchange (ETDEWEB)

Chou, Dean-Yi; Zhao Hui; Yang, Ming-Hsu; Liang, Zhi-Chao, E-mail: chou@phys.nthu.edu.tw [Physics Department, National Tsing Hua University, Hsinchu, Taiwan (China)

2012-10-20

Solar acoustic waves are scattered by a sunspot due to the interaction between the acoustic waves and the sunspot. The sunspot, excited by the incident wave, generates the scattered wave. The scattered wave is added to the incident wave to form the total wave around the sunspot. The interference fringes between the scattered wave and the incident wave are visible in the intensity of the total wave because the coherent time of the incident wave is of the order of a wave period. The strength of the interference fringes anti-correlates with the width of temporal spectra of the incident wave. The separation between neighboring fringes increases with the incident wavelength and the sunspot size. The strength of the fringes increases with the radial order n of the incident wave from n = 0 to n = 2, and then decreases from n = 2 to n = 5. The interference fringes play a role analogous to holograms in optics. This study suggests the feasibility of using the interference fringes to reconstruct the scattered wavefields of the sunspot, although the quality of the reconstructed wavefields is sensitive to the noise and errors in the interference fringes.

Alternate transmission with half-duplex relaying in MIMO interference relay networks

KAUST Repository

Park, Seongho

2013-12-01

In this paper, we consider an alternate transmission scheme for a multiple-input multiple-output interference relay channel where multiple sources transmit their own signals to their corresponding destinations via one of two relaying groups alternately every time phase. Each of the relaying groups has arbitrary number of relays, and each relay operates in half-duplex amplify-and-forward mode. In our scheme, the received signals at the relay nodes consist of desired signals and two different interference signals such as the inter-source interferences and the inter-group interferences which are caused by the phase incoherence of relaying. As such, we propose an iterative interference alignment algorithm to mitigate the interferences. We show that our proposed scheme achieves additional degrees of freedom compared to the conventional half-duplex relaying system in the interference relay channels. © 2013 IEEE.

Image hiding using optical interference

Science.gov (United States)

Zhang, Yan; Wang, Weining

2010-09-01

Optical image encryption technology has attracted a lot of attentions due to its large capacitance and fast speed. In conventional image encryption methods, the random phase masks are used as encryption keys to encode the images into white noise distribution. Therefore, this kind of methods requires interference technology to record complex amplitude and is vulnerable to attack techniques. The image hiding methods which employ the phase retrieve algorithm to encode the images into two or more phase masks are proposed, the hiding process is carried out within a computer using iterative algorithm. But the iterative algorithms are time consumed. All method mentioned above are based on the optical diffraction of the phase masks. In this presentation, a new optical image hiding method based on optical interference is proposed. The coherence lights which pass through two phase masks are combined by a beam splitter. Two beams interfere with each other and the desired image appears at the pre-designed plane. Two phase distribution masks are design analytically; therefore, the hiding speed can be obviously improved. Simulation results are carried out to demonstrate the novelty of the new proposed methods. This method can be expanded for double images hiding.

Quantum interference in plasmonic circuits.

Science.gov (United States)

Heeres, Reinier W; Kouwenhoven, Leo P; Zwiller, Valery

2013-10-01

Surface plasmon polaritons (plasmons) are a combination of light and a collective oscillation of the free electron plasma at metal/dielectric interfaces. This interaction allows subwavelength confinement of light beyond the diffraction limit inherent to dielectric structures. As a result, the intensity of the electromagnetic field is enhanced, with the possibility to increase the strength of the optical interactions between waveguides, light sources and detectors. Plasmons maintain non-classical photon statistics and preserve entanglement upon transmission through thin, patterned metallic films or weakly confining waveguides. For quantum applications, it is essential that plasmons behave as indistinguishable quantum particles. Here we report on a quantum interference experiment in a nanoscale plasmonic circuit consisting of an on-chip plasmon beamsplitter with integrated superconducting single-photon detectors to allow efficient single plasmon detection. We demonstrate a quantum-mechanical interaction between pairs of indistinguishable surface plasmons by observing Hong-Ou-Mandel (HOM) interference, a hallmark non-classical interference effect that is the basis of linear optics-based quantum computation. Our work shows that it is feasible to shrink quantum optical experiments to the nanoscale and offers a promising route towards subwavelength quantum optical networks.

Low-intensity interference effects and hidden-variable theories

Energy Technology Data Exchange (ETDEWEB)

Buonomano, V [Universidade Estadual de Campinas (Brazil). Inst. de Matematica

1978-05-11

The double-slit interference experiment and other similar experiments in the low-intensity limit (that is, one photon in the apparatus at a time) are examined in the spirit of Bell's work from the point of view of hidden-variable theories. It is found that there exists a class of hidden-variable theories which disagrees with quantum mechanics for a certain type of interference experiment. A manufactured conceptualization of this class, which is a particle view of interference, is described. An experiment, which appears to be feasible, is proposed to examine this disagreement.

Stroop-interference effect in post-traumatic stress disorder.

Science.gov (United States)

Cui, Hong; Chen, Guoliang; Liu, Xiaohui; Shan, Moshui; Jia, Yanyan

2014-12-01

To investigate the conflict processing in posttraumatic stress disorder (PTSD) patients, we conducted the classical Stroop task by recording event-related potentials. Although the reaction time was overall slower for PTSD patients than healthy age-matched control group, the Stroop-interference effect of reaction time did not differ between the two groups. Compared with normal controls, the interference effects of N 2 and N 450 components were larger and the interference effect of slow potential component disappeared in PTSD. These data indicated the dysfunction of conflict processing in individuals with PTSD.

Digital lock-in techniques for adaptive power-line interference extraction.

Science.gov (United States)

Dobrev, Dobromir; Neycheva, Tatyana; Mudrov, Nikolay

2008-07-01

This paper presents a simple digital approach for adaptive power-line (PL) or other periodic interference extraction. By means of two digital square (or sine) wave mixers, the real and imaginary parts of the interference are found, and the interference waveform is synthesized and finally subtracted. The described technique can be implemented in an open-loop architecture where the interference is synthesized as a complex sinusoid or in a closed-loop architecture for automatic phase and gain control. The same approach can be used for removal of the fundamental frequency of the PL interference as well as its higher harmonics. It is suitable for real-time operation with popular low-cost microcontrollers.

Interference-Fit Life Factors for Ball Bearings

Science.gov (United States)

Oswald, Fred B.; Zaretsky, Erwin V.; Poplawski, Joseph V.

2010-01-01

The effect of hoop stresses on the rolling-element fatigue life of angular-contact and deep-groove ball bearings was determined for common inner-ring interference fits at the ABEC-5 tolerance level. The analysis was applied to over 1150 bearing configurations and load cases. Hoop stresses were superimposed on the Hertzian principal stresses created by the applied bearing load to calculate the inner-race maximum shearing stress. The resulting fatigue life of the bearing was recalculated through a series of equations. The reduction in the fatigue life is presented as life factors that are applied to the unfactored bearing life. The life factors found in this study ranged from 1.00 (no life reduction)--where there was no net interface pressure--to a worst case of 0.38 (a 62-percent life reduction). For a given interference fit, the reduction in life is different for angular-contact and deep-groove ball bearings. Interference fits also affect the maximum Hertz stress-life relation. Experimental data of Czyzewski, showing the effect of interference fit on rolling-element fatigue life, were reanalyzed to determine the shear stress-life exponent. The Czyzewski data shear stress-life exponent c equals 8.77, compared with the assumed value of 9. Results are presented as tables and charts of life factors for angular-contact and deep-groove ball bearings with light, normal, and heavy loads and interference fits ranging from extremely light to extremely heavy.

General Quantum Interference Principle and Duality Computer

International Nuclear Information System (INIS)

Long Guilu

2006-01-01

In this article, we propose a general principle of quantum interference for quantum system, and based on this we propose a new type of computing machine, the duality computer, that may outperform in principle both classical computer and the quantum computer. According to the general principle of quantum interference, the very essence of quantum interference is the interference of the sub-waves of the quantum system itself. A quantum system considered here can be any quantum system: a single microscopic particle, a composite quantum system such as an atom or a molecule, or a loose collection of a few quantum objects such as two independent photons. In the duality computer, the wave of the duality computer is split into several sub-waves and they pass through different routes, where different computing gate operations are performed. These sub-waves are then re-combined to interfere to give the computational results. The quantum computer, however, has only used the particle nature of quantum object. In a duality computer, it may be possible to find a marked item from an unsorted database using only a single query, and all NP-complete problems may have polynomial algorithms. Two proof-of-the-principle designs of the duality computer are presented: the giant molecule scheme and the nonlinear quantum optics scheme. We also propose thought experiment to check the related fundamental issues, the measurement efficiency of a partial wave function.

FastICA peel-off for ECG interference removal from surface EMG.

Science.gov (United States)

Chen, Maoqi; Zhang, Xu; Chen, Xiang; Zhu, Mingxing; Li, Guanglin; Zhou, Ping

2016-06-13

Multi-channel recording of surface electromyographyic (EMG) signals is very likely to be contaminated by electrocardiographic (ECG) interference, specifically when the surface electrode is placed on muscles close to the heart. A novel fast independent component analysis (FastICA) based peel-off method is presented to remove ECG interference contaminating multi-channel surface EMG signals. Although demonstrating spatial variability in waveform shape, the ECG interference in different channels shares the same firing instants. Utilizing the firing information estimated from FastICA, ECG interference can be separated from surface EMG by a "peel off" processing. The performance of the method was quantified with synthetic signals by combining a series of experimentally recorded "clean" surface EMG and "pure" ECG interference. It was demonstrated that the new method can remove ECG interference efficiently with little distortion to surface EMG amplitude and frequency. The proposed method was also validated using experimental surface EMG signals contaminated by ECG interference. The proposed FastICA peel-off method can be used as a new and practical solution to eliminating ECG interference from multichannel EMG recordings.

A single antenna interference cancellation and adaptive technique based on ALOE

Directory of Open Access Journals (Sweden)

Xu Han

2017-02-01

Full Text Available A new type of single antenna interference cancellation (SAIC algorithm based on ALOE filtering module is introduced for co-channel interference cancellation in GSM/GPRS/EDGE downlink without changing the link structure of traditional receiver.Meanwhile,an adjacent frequency adaptive detection based on power spectrum estimation method is introduced to solve adjacent frequency interference and complex interference.Compared with traditional energy noise estimation method,the new method has simpler structure,less complexity,and can effectively improve the adaptability for various scenarios.The simulation results show that it can raise the resistance to co-channel frequency interference and adjacent frequency interference in multimode chips with low complexity,which improves the quality of 2G voice communication.

WhatsApp Messenger as a Learning Tool: An Investigation of Pre-Service Teachers' Learning without Instructor Presence

Science.gov (United States)

Alenazi, Ali A.

2018-01-01

This study investigated the extent to which pre-service teachers can utilize WhatsApp Messenger to create an effective learning platform without instructor interference. Twenty-six male pre-service teachers created a WhatsApp group and interacted through it independently for nine weeks. Each pre-service teacher was required to share a minimum of…

Interference in a thick plate at large angle of incidence

International Nuclear Information System (INIS)

Tavassoli, M.T.; Shah Shehany, F.

1991-01-01

A new approach to the interference in a plane parallel plate is introduced which is valid for any angle of incidence and any thickness. It is shown that the interference in a plate can be interpreted as the interference in a double-slit and the corresponding parameters are derived. It is also shown that for a particular angle of incidence, which depends only on the refractive index, the interfringes are minimum. It is proved theoretically and verified experimentally that the interference around this particular angle of incidence has several exploitable features which include: a) In thick plates large numbers of equidistant fringes are formed which are very adequate for producing interference gratings. b) It provides, in comparison to the conventional interferometric methods, an easier and more accurate means for direct measurement of wave-length. c) Multiple-beam interference at this particular angle improve the accuracy of the measurement of the fine structures of the atomic spectra, compared to other interferometric methods. (author). 4 refs, 4 figs

Interference suppression capabilities of smart cognitive-femto networks (SCFN)

KAUST Repository

Shakir, Muhammad; Atat, Rachad; Alouini, Mohamed-Slim

2013-01-01

Cognitive Radios are considered a standard part of future heterogeneous mobile network architectures. In this chapter, a two tier heterogeneous network with multiple Radio Access Technologies (RATs) is considered, namely (1) the secondary network, which comprises of Cognitive-Femto BS (CFBS), and (2) the macrocell network, which is considered a primary network. By exploiting the cooperation among the CFBS, the multiple CFBS can be considered a single base station with multiple geographically dispersed antennas, which can reduce the interference levels by directing the main beam toward the desired femtocell mobile user. The resultant network is referred to as Smart Cognitive-Femto Network (SCFN). In order to determine the effectiveness of the proposed smart network, the interference rejection capabilities of the SCFN is studied. It has been shown that the smart network offers significant performance improvements in interference suppression and Signal to Interference Ratio (SIR) and may be considered a promising solution to the interference management problems in future heterogeneous networks. © 2013, IGI Global.

Interference Reduction Selected Measurement Signals of Ships

Directory of Open Access Journals (Sweden)

Jan Monieta

2014-08-01

Full Text Available The paper presents problems encountered at the signal processing of mechanical values with electric methods. Depending on the measured quantity, the location of the sensors and the analysis frequency band, they are differently interferences. The article presents the results of applying the analysis of parameters of working and accompanying process marine medium speed reciprocating engines in the time, amplitude, frequency domain and wavelet analysis to select a reasonable method. The applied signal acquisition program allows you to perform some analysis of signals in different areas and the transformation of the data to other programs. The ways of interference reducing at various stages of their occurrence and analysis are presented. [b]Keywords[/b]: electrical signals, domain analysis, measurement interference

Base band data for testing interference mitigation algorithms

NARCIS (Netherlands)

Bell, JF; Hall, PJ; Wilson, WE; Sault, RJ; Smegal, RJ; Smith, MR; van Straten, W; Kesteven, MJ; Ferris, RH; Briggs, FH; Carrad, GJ; Sinclair, MW; Gough, RG; Sarkissian, JM; Bunton, JD; Bailes, M

Digital signal processing is one of many valuable tools for suppressing unwanted signals or interference. Building hardware processing engines seems to be the way to best implement some classes of interference suppression but is, unfortunately, expensive and time-consuming, especially if several

Detection-dependent six-photon Holland-Burnett state interference

Science.gov (United States)

Jin, Rui-Bo; Fujiwara, Mikio; Shimizu, Ryosuke; Collins, Robert J.; Buller, Gerald S.; Yamashita, Taro; Miki, Shigehito; Terai, Hirotaka; Takeoka, Masahiro; Sasaki, Masahide

2016-11-01

The NOON state, and its experimental approximation the Holland-Burnett state, have important applications in phase sensing measurement with enhanced sensitivity. However, most of the previous Holland-Burnett state interference (HBSI) experiments only investigated the area of the interference pattern in the region immediately around zero optical path length difference, while the full HBSI pattern over a wide range of optical path length differences has not yet been well explored. In this work, we experimentally and theoretically demonstrate up to six-photon HBSI and study the properties of the interference patterns over a wide range of optical path length differences. It was found that the shape, the coherence time and the visibility of the interference patterns were strongly dependent on the detection schemes. This work paves the way for applications which are based on the envelope of the HBSI pattern, such as quantum spectroscopy and quantum metrology.

Visualizing the Solute Vaporization Interference in Flame Atomic Absorption Spectroscopy

Science.gov (United States)

Dockery, Christopher R.; Blew, Michael J.; Goode, Scott R.

2008-01-01

Every day, tens of thousands of chemists use analytical atomic spectroscopy in their work, often without knowledge of possible interferences. We present a unique approach to study these interferences by using modern response surface methods to visualize an interference in which aluminum depresses the calcium atomic absorption signal. Calcium…

An update on mobile phones interference with medical devices.

Science.gov (United States)

Mahmoud Pashazadeh, Ali; Aghajani, Mahdi; Nabipour, Iraj; Assadi, Majid

2013-10-01

Mobile phones' electromagnetic interference with medical devices is an important issue for the medical safety of patients who are using life-supporting medical devices. This review mainly focuses on mobile phones' interference with implanted medical devices and with medical equipment located in critical areas of hospitals. A close look at the findings reveals that mobile phones may adversely affect the functioning of medical devices, and the specific effect and the degree of interference depend on the applied technology and the separation distance. According to the studies' findings and the authors' recommendations, besides mitigating interference, using mobile phones at a reasonable distance from medical devices and developing technology standards can lead to their effective use in hospital communication systems.

An update on mobile phones interference with medical devices

International Nuclear Information System (INIS)

Pashazadeh, A. M.; Aghajani, M.; Nabipour, I.; Assadi, M.

2013-01-01

Mobile phones' electromagnetic interference with medical devices is an important issue for the medical safety of patients who are using life-supporting medical devices. This review mainly focuses on mobile phones' interference with implanted medical devices and with medical equipment located in critical areas of hospitals. A close look at the findings reveals that mobile phones may adversely affect the functioning of medical devices, and the specific effect and the degree of interference depend on the applied technology and the separation distance. According to the studies' findings and the authors' recommendations, besides mitigating interference, using mobile phones at a reasonable distance from medical devices and developing technology standards can lead to their effective use in hospital communication systems. (authors)

The Michelson interferometer-how to detect invisible interference patterns

International Nuclear Information System (INIS)

Verovnik, Ivo; Likar, Andrej

2004-01-01

In a Michelson interferometer, the contrast of the interference pattern fades away due to incoherence of light when the mirrors are not in equidistant positions. We propose an experiment where the distance between the interference fringes can be determined, even when the difference in length of the interferometer arms is far beyond the coherence length of the light, i.e. when the interference pattern disappears completely for the naked eye. We used a semiconductor laser with two photodiodes as sensors, which enabled us to follow the fluctuations of the light intensity on the screen. The distance between invisible interference fringes was determined from periodic changes of the summed fluctuating signal, obtained by changing the distance between the two sensors

Using Just-in-Time Information to Support Scientific Discovery Learning in a Computer-Based Simulation

Science.gov (United States)

Hulshof, Casper D.; de Jong, Ton

2006-01-01

Students encounter many obstacles during scientific discovery learning with computer-based simulations. It is hypothesized that an effective type of support, that does not interfere with the scientific discovery learning process, should be delivered on a "just-in-time" base. This study explores the effect of facilitating access to…

Handling of uncertainty due to interference fringe in FT-NIR transmittance spectroscopy - Performance comparison of interference elimination techniques using glucose-water system

Science.gov (United States)

Beganović, Anel; Beć, Krzysztof B.; Henn, Raphael; Huck, Christian W.

2018-05-01

The applicability of two elimination techniques for interferences occurring in measurements with cells of short pathlength using Fourier transform near-infrared (FT-NIR) spectroscopy was evaluated. Due to the growing interest in the field of vibrational spectroscopy in aqueous biological fluids (e.g. glucose in blood), aqueous solutions of D-(+)-glucose were prepared and split into a calibration set and an independent validation set. All samples were measured with two FT-NIR spectrometers at various spectral resolutions. Moving average smoothing (MAS) and fast Fourier transform filter (FFT filter) were applied to the interference affected FT-NIR spectra in order to eliminate the interference pattern. After data pre-treatment, partial least squares regression (PLSR) models using different NIR regions were constructed using untreated (interference affected) spectra and spectra treated with MAS and FFT filter. The prediction of the independent validation set revealed information about the performance of the utilized interference elimination techniques, as well as the different NIR regions. The results showed that the combination band of water at approx. 5200 cm-1 is of great importance since its performance was superior to the one of the so-called first overtone of water at approx. 6800 cm-1. Furthermore, this work demonstrated that MAS and FFT filter are fast and easy-to-use techniques for the elimination of interference fringes in FT-NIR transmittance spectroscopy.

[An Algorithm to Eliminate Power Frequency Interference in ECG Using Template].

Science.gov (United States)

Shi, Guohua; Li, Jiang; Xu, Yan; Feng, Liang

2017-01-01

Researching an algorithm to eliminate power frequency interference in ECG. The algorithm first creates power frequency interference template, then, subtracts the template from the original ECG signals, final y, the algorithm gets the ECG signals without interference. Experiment shows the algorithm can eliminate interference effectively and has none side effect to normal signal. It’s efficient and suitable for practice.

Emotions, cognitive interference, and concentration disruption in youth sport.

Science.gov (United States)

McCarthy, Paul J; Allen, Mark S; Jones, Marc V

2013-01-01

We explored the relationship between emotions, cognitive interference, concentration disruption and performance in youth sport. In study 1, 150 youth sport athletes (Mage = 13.13 years, s = 1.79) completed measures of emotion, cognitive interference, and concentration disruption for their most recently completed competition. In Study 2, 46 female rhythmic gymnasts (Mage = 10.30 years, s = 1.74) completed measures of emotion immediately before competition, and measures of cognitive interference and concentration disruption immediately after competition. Study 1 showed that anxiety and dejection were associated with more interfering thoughts and greater disruptions in concentration, whereas the effects of anger and happiness on interfering thoughts differed relative to the age of participants. Specifically, anger was associated with more interfering thoughts only in younger athletes and happiness was associated with fewer interfering thoughts only in older athletes. Study 2 showed that emotions experienced before competition were not strongly associated with cognitive interference or concentration disruption, but athletes reporting more thoughts of escape in competition were less successful in the competition as measured by objective performance scores. These findings demonstrate that emotions are important for cognitive interference and concentration disruption, and provide some initial evidence that cognitive interference is important for performance in youth sport.

Quantum coherence generated by interference-induced state selectiveness

OpenAIRE

Garreau, Jean Claude

2001-01-01

The relations between quantum coherence and quantum interference are discussed. A general method for generation of quantum coherence through interference-induced state selection is introduced and then applied to `simple' atomic systems under two-photon transitions, with applications in quantum optics and laser cooling.

A New Design Approach to game or play based learning

DEFF Research Database (Denmark)

Larsen, Lasse Juel

to ground the students sense of meaning. This paper proposes another approach: using visualization in immersive 3D-worlds as documentation of learning progress while at the same time constituting a reward system which motivate further learning. The overall design idea is to build a game based learning......Abstract: The present paper proposes a new design perspective for game based learning. The general idea is to abandon the long and sought after dream of designing a closed learning system, where students from elementary school to high school without teachers’ interference could learn whatever...... game based learning system, but also confront aspects of modern learning theory especially the notion of reference between content of an assignment and the reality with which it should or could be connected (situated learning). The second idea promotes a way to tackle the common experience...

Intraindividual Coupling of Daily Stressors and Cognitive Interference in Old Age

Science.gov (United States)

Mogle, Jacqueline; Sliwinski, Martin J.

2011-01-01

Objectives. The current study examined emotional and cognitive reactions to daily stress. We examined the psychometric properties of a short cognitive interference measure and how cognitive interference was associated with measures of daily stress and negative affect (NA) between persons and within persons over time. Methods. A sample of 87 older adults (Mage = 83, range = 70–97, 28% male) completed measures of daily stress, cognitive interference, and NA on 6 days within a 14-day period. Results. The measure yielded a single-factor solution with good reliability both between and within persons. At the between-person level, NA accounted for the effects of daily stress on individual differences in cognitive interference. At the within-person level, NA and daily stress were unique predictors of cognitive interference. Furthermore, the within-person effect of daily stress on cognitive interference decreased significantly with age. Discussion. These results support theoretical work regarding associations among stress, NA, and cognitive interference, both across persons and within persons over time. PMID:21743045

Interference Cancelation Schemes for Uplink Transmission in Femtocells

DEFF Research Database (Denmark)

Thai, Chan; Popovski, Petar

2010-01-01

We present techniques that solve the near-far problems in femtocell networks. When a co-channel configuration is used, a transmission in the macrocell may cause interference to a femtocell. We introduce methods to cancel the interference caused by the macrocell to a femtocell by using the high......-rate link between the macrocell base station (BS) and the femtocell BS. In such a way, the interference from macrocell transmitters is completely cancelled when uplink transmission is used in the femtocell. Therefore, the allocation of time slots for uplink/downlink in a femtocell can be done by trying only...

Reproductive Interference and Niche Partitioning in Aphidophagous Insects

Directory of Open Access Journals (Sweden)

Suzuki Noriyuki

2016-01-01

Full Text Available The range and quality of prey species differ greatly among closely related species of predators. However, the factors responsible for this diversified niche utilization are unclear. This is because the predation and resource competition do not always prevent species coexistence. In this paper, we present evidence in support of reproductive interference as a driver of niche partitioning, focusing on aphidophagous insect. Firstly, we present closely related generalist and specialist species pairs in aphidophagous lacewings to compare the reproductive interference hypothesis with two other hypotheses that have been proposed to explain niche partitioning in lacewings and sympatric speciation through host race formation and sexual selection. Secondly, we present a case study that shows how reproductive interference can drive niche partitioning in sibling ladybird species. Thirdly, we show that many ladybird genera include species inhabiting the same region but having different food and habitat preferences, raising the possibility that reproductive interference might occur in these groups. Finally, we show that intraguild predation cannot always explain the niche partitioning in aphidophagous insects including hoverflies and parasitoids. On the basis of the evidence presented, we urge that future studies investigating predator communities should take account of the role of reproductive interference.

Resolving semantic and proactive interference in memory over the short-term.

Science.gov (United States)

Atkins, Alexandra S; Berman, Marc G; Reuter-Lorenz, Patricia A; Lewis, Richard L; Jonides, John

2011-07-01

Interference is a major source of short-term errors of memory. The present investigation explores the relationship between two important forms of interference: proactive interference (PI), induced by the need to reject recently studied items no longer relevant to task performance, and semantic interference (SI), induced by the need to reject lures sharing a meaningful relationship with current memoranda. We explore the possibility that shared cognitive control processes are recruited to resolve both forms of interference. In Experiment 1, we find that the requirement to engage in articulatory suppression during the retention interval of tasks that induce either PI or SI increases both forms of interference similarly and selectively. In Experiment 2, we develop a task to examine PI and SI within the same experimental context. The results show interactive effects between factors that lead to the two forms of interference. Taken together, these findings support contextual-cuing models of short-term remembering (Nairne, Annual Review of Psychology, 53, 53-81 2002), where the context in which retrieval occurs can influence susceptibility to interference. Lastly, we discuss several theoretical hypotheses concerning the cognitive control processes that are recruited to resolve SI and PI in short-term remembering.

The path of chewing movement before and after experimental occlusal interference.

Science.gov (United States)

Kobayashi, Y; Shiga, H

1991-01-01

To understand functions of the masticatory system accurate recording and analysis of mandibular movement are indispensable. The purpose of this experiment was to find functional differences in the path of masticatory movement due to experimental occlusal interference. Occlusal interference was placed on the mandibular first molar or cuspid of the habitual chewing side in seven normal subjects. While subjects were asked to masticate gum on one side at a time, jaw movements were recorded and analyzed using an automatic masticatory movement analysis system previously developed. Standard deviations (SD) of the vertical and lateral elements in the opening and closing phases were calculated and compared before and after the occlusal interference. In the opening phase the SDs increased significantly with either the interference placed on the cuspid or molar tooth. In the closing phase it generally increased with either the interference. The effect was significantly more with the cuspid interference than that of the molar tooth. The SD of the vertical element is also generally increased with either interference. However, in contrast to the lateral element, the effect of the molar interference on the vertical element was significantly more than that of the cuspid.

Coupled interference based rate adaptation in ad hoc networks

CSIR Research Space (South Africa)

Awuor, F

2011-09-01

Full Text Available of learning and adjustment rules converge to it, e.g., optimal (best) response dynamics). Assume (I; (p); (ui)) is a super modular game. Then Bi(p i) in (7) has a greatest and least element, denoted by Bi(p i) and Bi(p i), and if p0 i p i then Bi(p 0 i...) Bi(p i) and B i(p0 i) B i(p i) [15], [16] This implies that each player?s best response is increasing in the actions of other players. The set of strategies that survive iterated strict dominance (i.e. iterated elimination of strictly dominated...

An inter-lighting interference cancellation scheme for MISO-VLC systems

Science.gov (United States)

Kim, Kyuntak; Lee, Kyujin; Lee, Kyesan

2017-08-01

In this paper, we propose an inter-lighting interference cancellation (ILIC) scheme to reduce the interference between adjacent light-emitting diodes (LEDs) and enhance the transmission capacity of multiple-input-single-output (MISO)-visible light communication (VLC) systems. In indoor environments, multiple LEDs have normally been used as lighting sources, allowing the design of MISO-VLC systems. To enhance the transmission capacity, different data should be simultaneously transmitted from each LED; however, that can lead to interference between adjacent LEDs. In that case, relatively low-received power signals are subjected to large interference because wireless optical systems generally use intensity modulation and direct detection. Thus, only the signal with the highest received power can be detected, while the other received signals cannot be detected. To solve this problem, we propose the ILIC scheme for MISO-VLC systems. The proposed scheme preferentially detects the highest received power signal, and this signal is referred as interference signal by an interference component generator. Then, relatively low-received power signal can be detected by cancelling the interference signal from the total received signals. Therefore, the performance of the proposed scheme can improve the total average bit error rate and throughput of a MISO-VLC system.

A Dependable Localization Algorithm for Survivable Belt-Type Sensor Networks.

Science.gov (United States)

Zhu, Mingqiang; Song, Fei; Xu, Lei; Seo, Jung Taek; You, Ilsun

2017-11-29

As the key element, sensor networks are widely investigated by the Internet of Things (IoT) community. When massive numbers of devices are well connected, malicious attackers may deliberately propagate fake position information to confuse the ordinary users and lower the network survivability in belt-type situation. However, most existing positioning solutions only focus on the algorithm accuracy and do not consider any security aspects. In this paper, we propose a comprehensive scheme for node localization protection, which aims to improve the energy-efficient, reliability and accuracy. To handle the unbalanced resource consumption, a node deployment mechanism is presented to satisfy the energy balancing strategy in resource-constrained scenarios. According to cooperation localization theory and network connection property, the parameter estimation model is established. To achieve reliable estimations and eliminate large errors, an improved localization algorithm is created based on modified average hop distances. In order to further improve the algorithms, the node positioning accuracy is enhanced by using the steepest descent method. The experimental simulations illustrate the performance of new scheme can meet the previous targets. The results also demonstrate that it improves the belt-type sensor networks' survivability, in terms of anti-interference, network energy saving, etc.

Tortious Interference with Contract versus "Efficient" Breach: Theory and Empirical Evidence.

OpenAIRE

McChesney, Fred S

1999-01-01

Tortious interference is bothersome, normatively and positively, to scholars espousing the economic model of "efficient breach" of contract because it penalizes third-party inducements to breach. Scholars nonetheless find innovative second-best arguments to justify the coexistence of tortious interference with "efficient" breach. This article shows normatively why tortious interference would be part of a first-best legal system. Tortious interference provides property protection to contract r...

Mobile communication devices causing interference in invasive and noninvasive ventilators.

Science.gov (United States)

Dang, Bao P; Nel, Pierre R; Gjevre, John A

2007-06-01

The aim of this study was to assess if common mobile communication systems would cause significant interference on mechanical ventilation devices and at what distances would such interference occur. We tested all the invasive and noninvasive ventilatory devices used within our region. This consisted of 2 adult mechanical ventilators, 1 portable ventilator, 2 pediatric ventilators, and 2 noninvasive positive pressure ventilatory devices. We operated the mobile devices from the 2 cellular communication systems (digital) and 1 2-way radio system used in our province at varying distances from the ventilators and looked at any interference they created. We tested the 2-way radio system, which had a fixed operation power output of 3.0 watts, the Global Systems for Mobile Communication cellular system, which had a maximum power output of 2.0 watts and the Time Division Multiple Access cellular system, which had a maximum power output of 0.2 watts on our ventilators. The ventilators were ventilating a plastic lung at fixed settings. The mobile communication devices were tested at varying distances starting at zero meter from the ventilator and in all operation modes. The 2-way radio caused the most interference on some of the ventilators, but the maximum distance of interference was 1.0 m. The Global Systems for Mobile Communication system caused significant interference only at 0 m and minor interference at 0.5 m on only 1 ventilator. The Time Division Multiple Access system caused no interference at all. Significant interference consisted of a dramatic rise and fluctuation of the respiratory rate, pressure, and positive end-expiratory pressure of the ventilators with no normalization when the mobile device was removed. From our experiment on our ventilators with the communication systems used in our province, we conclude that mobile communication devices such as cellular phones and 2-way radios are safe and cause no interference unless operated at very close distances of

Interference Lithography for Vertical Photovoltaics

Science.gov (United States)

Balls, Amy; Pei, Lei; Kvavle, Joshua; Sieler, Andrew; Schultz, Stephen; Linford, Matthew; Vanfleet, Richard; Davis, Robert

2009-10-01

We are exploring low cost approaches for fabricating three dimensional nanoscale structures. These vertical structures could significantly improve the efficiency of devices made from low cost photovoltaic materials. The nanoscale vertical structure provides a way to increase optical absorption in thin photovoltaic films without increasing the electronic carrier separation distance. The target structure is a high temperature transparent template with a dense array of holes on a 400 - 600 nm pitch fabricated by a combination of interference lithography and nanoembossing. First a master was fabricated using ultraviolet light interference lithography and the pattern was transferred into a silicon wafer master by silicon reactive ion etching. Embossing studies were performed with the master on several high temperature polymers.

Advances in the analysis of pressure interference tests

Energy Technology Data Exchange (ETDEWEB)

Martinez R, N. [Petroleos Mexicanos, PEMEX, Mexico City (Mexico); Samaniego V, F. [Univ. Nacional Autonoma de Mexico (Mexico)

2010-12-15

This paper presented an extension for radial, linear, and spherical flow conditions of the El-Khatib method for analyzing pressure interference tests through utilization of the pressure derivative. Conventional analysis of interference tests considers only radial flow, but some reservoirs have physical field conditions in which linear or spherical flow conditions prevail. The INTERFERAN system, a friendly computer code for the automatic analysis of pressure interference tests, was also discussed and demonstrated by way of 2 field cases. INTERFERAN relies on the principle of superposition in time and space to interpret a test of several wells with variable histories of production or injection or both. The first field case addressed interference tests conducted in the naturally fractured geothermal field of Klamath Falls, and the second field case was conducted in a river-formed bed in which linear flow conditions are dominant. The analysis was deemed to be reliable. 13 refs., 1 tab., 7 figs.

[Characteristics of experimental occlusal interference-induced masticatory mechanical hyperalgesia of rats].

Science.gov (United States)

Li, Xuejiao; Cao, Ye; Xie, Qiufei

2014-10-01

To investigate the relationship between the existence of occlusal interference and masticatory muscle hyperalgesia by exploring the stimulus-response relationship between the duration of occlusal interference and masticatory muscle mechanical withdrawal threshold. Occlusal interference with 0.4 mm-thick crowns on rat molars was removed under anaesthesia at 2, 3, 4, 5, and 6 d after wear, and masticatory muscle mechanical withdrawal threshold was tested at 1, 3, 5, 7, 10, 14, 21 and 28 d. Decreased mechanical withdrawal thresholds were detected in temporal muscles and masseter muscles on both sides following occlusal interference (P 0.05). No significant differences were detected between the contralateral side with the ipsilateral side (P occlusal interference at 5 d, and the existence of the occlusal interference is positively correlated with the duration of the mechanical hyperalgesia.

Electron Interference in Molecular Circular Polarization Attosecond XUV Photoionization

Directory of Open Access Journals (Sweden)

Kai-Jun Yuan

2015-01-01

Full Text Available Two-center electron interference in molecular attosecond photoionization processes is investigated from numerical solutions of time-dependent Schrödinger equations. Both symmetric H\\(_2^+\\ and nonsymmetric HHe\\(^{2+}\\ one electron diatomic systems are ionized by intense attosecond circularly polarized XUV laser pulses. Photoionization of these molecular ions shows signature of interference with double peaks (minima in molecular attosecond photoelectron energy spectra (MAPES at critical angles \\(\\vartheta_c\\ between the molecular \\(\\textbf{R}\\ axis and the photoelectron momentum \\(\\textbf{p}\\. The interferences are shown to be a function of the symmetry of electronic states and the interference patterns are sensitive to the molecular orientation and pulse polarization. Such sensitivity offers possibility for imaging of molecular structure and orbitals.

Occurrence and characteristics of mutual interference between LIDAR scanners

Science.gov (United States)

Kim, Gunzung; Eom, Jeongsook; Park, Seonghyeon; Park, Yongwan

2015-05-01

The LIDAR scanner is at the heart of object detection of the self-driving car. Mutual interference between LIDAR scanners has not been regarded as a problem because the percentage of vehicles equipped with LIDAR scanners was very rare. With the growing number of autonomous vehicle equipped with LIDAR scanner operated close to each other at the same time, the LIDAR scanner may receive laser pulses from other LIDAR scanners. In this paper, three types of experiments and their results are shown, according to the arrangement of two LIDAR scanners. We will show the probability that any LIDAR scanner will interfere mutually by considering spatial and temporal overlaps. It will present some typical mutual interference scenario and report an analysis of the interference mechanism.

Interference thinking in constructing students’ knowledge to solve mathematical problems

Science.gov (United States)

Jayanti, W. E.; Usodo, B.; Subanti, S.

2018-04-01

This research aims to describe interference thinking in constructing students’ knowledge to solve mathematical problems. Interference thinking in solving problems occurs when students have two concepts that interfere with each other’s concept. Construction of problem-solving can be traced using Piaget’s assimilation and accommodation framework, helping to know the students’ thinking structures in solving the problems. The method of this research was a qualitative method with case research strategy. The data in this research involving problem-solving result and transcripts of interviews about students’ errors in solving the problem. The results of this research focus only on the student who experience proactive interference, where student in solving a problem using old information to interfere with the ability to recall new information. The student who experience interference thinking in constructing their knowledge occurs when the students’ thinking structures in the assimilation and accommodation process are incomplete. However, after being given reflection to the student, then the students’ thinking process has reached equilibrium condition even though the result obtained remains wrong.

Dependence of AeroMACS Interference on Airport Radiation Pattern Characteristics

Science.gov (United States)

Wilson, Jeffrey D.

2012-01-01

AeroMACS (Aeronautical Mobile Airport Communications System), which is based upon the IEEE 802.16e mobile wireless standard, is expected to be implemented in the 5091 to 5150 MHz frequency band. As this band is also occupied by Mobile Satellite Service (MSS) feeder uplinks, AeroMACS must be designed to avoid interference with this incumbent service. The aspects of AeroMACS operation that present potential interference are under analysis in order to enable the definition of standards that assure that such interference will be avoided. In this study, the cumulative interference power distribution at low earth orbit from AeroMACS transmitters at the 497 major airports in the contiguous United States was simulated with the Visualyse Professional software. The dependence of the interference power on the number of antenna beams per airport, gain patterns, and beam direction orientations was simulated. As a function of these parameters, the simulation results are presented in terms of the limitations on transmitter power required to maintain the cumulative interference power under the established threshold.

Interference in wireless ad hoc networks with smart antennas

KAUST Repository

Alabdulmohsin, Ibrahim

2014-08-01

In this paper, we show that the use of directional antennas in wireless ad hoc networks can actually increase interference due to limitations of virtual carrier sensing. We derive a simple mathematical expression for interference in both physical and virtual carrier sense networks, which reveals counter-intuitively that receivers in large dense networks with directional antennas can experience larger interference than in omnidirectional networks unless the beamwidth is sufficiently small. Validity of mathematical analysis is confirmed using simulations.

Intersystem Interference Reduction for Overlaid HAPS-Terrestrial CDMA System

Science.gov (United States)

Huang, Jeng-Ji; Wang, Wei-Ting; Li, Mingfu; Shiung, David; Ferng, Huei-Wen

In this letter, we propose that directional antennas, combined with power management, be incorporated to reduce intersystem interference in a shared band overlaid high altitude platform station (HAPS)-terrestrial code division multiple access (CDMA) system. To eliminate the HAPS to terrestrial interference, the HAPS is accessed only via directional antennas under the proposed scheme. By doing so, the uplink power to the HAPS can accordingly be increased, so that the terrestrial to HAPS interference is also effectively suppressed.

The Effects of Age on Short-Term Memory Loss due to Proactive Interference

Directory of Open Access Journals (Sweden)

Alisha Berkauzer

2011-01-01

Full Text Available This project focused on how proactive interference affects the short-term memory of people based on their age. The goal was to find the prime age for learning information and storing it in one's memory. Seven people from ages fifteen to forty were tested individually, using a set color pattern, in order to see how well each individual could remember the different color patterns as difficulty of the pattern increased. The obtained data was fitted by the polynomial regression. The “fitted” curve shows that as age increases, the individual's performance in memorizing the more difficult patterns decreases. Also, the peaked level of memory performance was found to be 24 for our experimental data.

Optical interference coatings for optics and photonics [Invited].

Science.gov (United States)

Lee, Cheng-Chung

2013-01-01

Optical interference coatings play as an important role in the progress in optics and photonics. In this article we give a minireview of the evolution of optical interference coatings from the theory, the design, to the manufacture. Some interesting but challenging topics for the future are also discussed.

Unraveling cell processes: interference imaging interwoven with data analysis

DEFF Research Database (Denmark)

Brazhe, Nadezda; Brazhe, Alexey; Pavlov, A N

2006-01-01

The paper presents results on the application of interference microscopy and wavelet-analysis for cell visualization and studies of cell dynamics. We demonstrate that interference imaging of erythrocytes can reveal reorganization of the cytoskeleton and inhomogenity in the distribution of hemoglo......The paper presents results on the application of interference microscopy and wavelet-analysis for cell visualization and studies of cell dynamics. We demonstrate that interference imaging of erythrocytes can reveal reorganization of the cytoskeleton and inhomogenity in the distribution...... properties differ from cell type to cell type and depend on the cellular compartment. Our results suggest that low frequency variations (0.1-0.6 Hz) result from plasma membrane processes and that higher frequency variations (20-26 Hz) are related to the movement of vesicles. Using double-wavelet analysis, we...... study the modulation of the 1 Hz rhythm in neurons and reveal its changes under depolarization and hyperpolarization of the plasma membrane. We conclude that interference microscopy combined with wavelet analysis is a useful technique for non-invasive cell studies, cell visualization, and investigation...

Neural mechanisms of interference control in working memory capacity.

Science.gov (United States)

Bomyea, Jessica; Taylor, Charles T; Spadoni, Andrea D; Simmons, Alan N

2018-02-01

The extent to which one can use cognitive resources to keep information in working memory is known to rely on (1) active maintenance of target representations and (2) downregulation of interference from irrelevant representations. Neurobiologically, the global capacity of working memory is thought to depend on the prefrontal and parietal cortices; however, the neural mechanisms involved in controlling interference specifically in working memory capacity tasks remain understudied. In this study, 22 healthy participants completed a modified complex working memory capacity task (Reading Span) with trials of varying levels of interference control demands while undergoing functional MRI. Neural activity associated with interference control demands was examined separately during encoding and recall phases of the task. Results suggested a widespread network of regions in the prefrontal, parietal, and occipital cortices, and the cingulate and cerebellum associated with encoding, and parietal and occipital regions associated with recall. Results align with prior findings emphasizing the importance of frontoparietal circuits for working memory performance, including the role of the inferior frontal gyrus, cingulate, occipital cortex, and cerebellum in regulation of interference demands. © 2017 Wiley Periodicals, Inc.

The beneficial influence of inattention on visual interference in schizophrenia.

Science.gov (United States)

Brodeur, Mathieu B; Kiang, Michael; Christensen, Bruce K

2016-09-01

Schizophrenia is associated with poor spatial attention. However, although this deficit undermines the perception of target information, it may be helpful for ignoring irrelevant inputs. The present study examined whether event-related brain potential (ERP) indices of visual spatial attention predicted the magnitude of the brain response to interference in schizophrenia. ERPs were recorded in 16 schizophrenia patients and 20 healthy control participants who had to indicate whether the target E was global or local in compound letter stimuli. The nontarget could be either highly similar to the target (i.e., a global E composed of local Ss and vice versa) and thus produce more interference, or it could be dissimilar (i.e., a global E composed of local Hs and vice versa) and generate less interference. Both groups' responses were slowed by interference. Voltage amplitudes of the P1, and of ERP interference effects from 300-500 ms after stimulus onset, were significantly smaller in schizophrenia patients than in healthy participants when the target was global. In patients, larger P1 amplitudes were correlated with larger interference effects and with more severe symptoms of attentional deficits and conceptual disorganization. Schizophrenia participants thus exhibited abnormal ERPs to interference despite normal behavioral performance. Schizophrenia patients likely pay less attention to stimuli in general; however, the impact of this impairment on target detection is compensated by relatively greater inattention to irrelevant components of the stimuli, and this explains why they are not more influenced by interference than healthy participants at the behavioral level. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Spatial working memory interferes with explicit, but not probabilistic cuing of spatial attention

Science.gov (United States)

Won, Bo-Yeong; Jiang, Yuhong V.

2014-01-01

Recent empirical and theoretical work has depicted a close relationship between visual attention and visual working memory. For example, rehearsal in spatial working memory depends on spatial attention, whereas adding a secondary spatial working memory task impairs attentional deployment in visual search. These findings have led to the proposal that working memory is attention directed toward internal representations. Here we show that the close relationship between these two constructs is limited to some but not all forms of spatial attention. In five experiments, participants held color arrays, dot locations, or a sequence of dots in working memory. During the memory retention interval they performed a T-among-L visual search task. Crucially, the probable target location was cued either implicitly through location probability learning, or explicitly with a central arrow or verbal instruction. Our results showed that whereas imposing a visual working memory load diminished the effectiveness of explicit cuing, it did not interfere with probability cuing. We conclude that spatial working memory shares similar mechanisms with explicit, goal-driven attention but is dissociated from implicitly learned attention. PMID:25401460

Visual Working Memory Capacity and Proactive Interference

OpenAIRE

Hartshorne, Joshua

2008-01-01

BACKGROUND: Visual working memory capacity is extremely limited and appears to be relatively immune to practice effects or the use of explicit strategies. The recent discovery that visual working memory tasks, like verbal working memory tasks, are subject to proactive interference, coupled with the fact that typical visual working memory tasks are particularly conducive to proactive interference, suggests that visual working memory capacity may be systematically under-estimated. METHODOLOGY/P...

Coincidence Imaging and interference with coherent Gaussian beams

Institute of Scientific and Technical Information of China (English)

CAI Yang-jian; ZHU Shi-yao

2006-01-01

we present a theoretical study of coincidence imaging and interference with coherent Gaussian beams The equations for the coincidence image formation and interference fringes are derived,from which it is clear that the imaging is due to the corresponding focusing in the two paths .The quality and visibility of the images and fringes can be high simultaneously.The nature of the coincidence imaging and interference between quantum entangled photon pairs and coherent Gaussian beams are different .The coincidence image with coherent Gaussian beams is due to intensity-intensity correspondence,a classical nature,while that with entangled photon pairs is due to the amplitude correlation a quantum nature.

Theory of fourfold interference with photon pairs from spatially separated sources

International Nuclear Information System (INIS)

Zhang, Hui Rong; Wang, Ruo Peng

2007-01-01

We present a theory for fourfold quantum interference of photons generated from independent spontaneous parametric down-conversion processes. Closed-form expressions for fourfold quantum interference patterns and visibility are found. The theoretical result for fourfold quantum interference patterns is in good agreement with experimental data reported. Detailed numerical calculations for the dependence of fourfold quantum interference visibility on experimentally controllable parameters are carried out. It is found out that higher visibility can be achieved for small biphoton width, short pump pulse coherence time, and narrow bandwidth of spectral filters. The optimal condition for obtaining at the same time higher fourfold interference visibility and intensity is also discussed

Interference effects in new physics processes at the LHC

International Nuclear Information System (INIS)

Fuchs, Elina

2015-09-01

Interference effects between nearly mass-degenerate particles are addressed in this thesis, comprising higher-order calculations, a modelindependent method to calculate interference terms efficiently and a phenomenological application to current Higgs searches at the LHC. Predictions of cross sections and decay widths can be severely affected by interference terms between quasi-degenerate states arising in models beyond the Standard Model. We formulate a generalisation of the narrow-width approximation (NWA) which allows for a consistent treatment of such effects by factorising the interference term into on-shell matrix elements of the production and decay parts, optionally further approximated as simple interference weight factors, incorporating oneloop and real corrections in a UV- and IR-finite way. We apply the generalised NWA to interfering MSSM Higgs bosons in the process χ 0 4 →χ 0 1 Φ→χ 0 1 τ + τ - , Φ=h, H and achieve an agreement of better than 1% with the unfactorised three-body decay of the neutralino χ 0 4 at NLO. Further, we derive the approximation of the full propagator matrix of the three neutral MSSM Higgs bosons in terms of Breit- Wigner propagators and on-shell wave-function normalisation factors Z. This is found to accurately reproduce the full mixing properties also in the case of complex MSSM parameters. Moreover, it enables the implementation of the total width at the highest available order. Using the Breit-Wigner and Z-factor formalism, we calculate CP-violating interference effects of the neutral MSSM Higgs bosons in the process b anti b→h 1,2,3 →τ +τ - , induced by the phase φ A t . We find a very significant, destructive interference between h 2 and h 3 , particularly for large μ. As a consequence, a considerable parameter region in the complex M mod+ h scenario, which would appear to be ruled out if this interference were neglected, actually escapes the current exclusion bounds from the LHC.

Comparisons of receive array interference reduction techniques under erroneous generalized transmit beamforming

KAUST Repository

Radaydeh, Redha Mahmoud

2014-02-01

This paper studies generalized single-stream transmit beamforming employing receive array co-channel interference reduction algorithms under slow and flat fading multiuser wireless systems. The impact of imperfect prediction of channel state information for the desired user spatially uncorrelated transmit channels on the effectiveness of transmit beamforming for different interference reduction techniques is investigated. The case of over-loaded receive array with closely-spaced elements is considered, wherein it can be configured to specified interfering sources. Both dominant interference reduction and adaptive interference reduction techniques for statistically ordered and unordered interferers powers, respectively, are thoroughly studied. The effect of outdated statistical ordering of the interferers powers on the efficiency of dominant interference reduction is studied and then compared against the adaptive interference reduction. For the system models described above, new analytical formulations for the statistics of combined signal-to-interference-plus-noise ratio are presented, from which results for conventional maximum ratio transmission and single-antenna best transmit selection can be directly deduced as limiting cases. These results are then utilized to obtain quantitative measures for various performance metrics. They are also used to compare the achieved performance of various configuration models under consideration. © 1972-2012 IEEE.

Different Loci of Semantic Interference in Picture Naming vs. Word-Picture Matching Tasks.

Science.gov (United States)

Harvey, Denise Y; Schnur, Tatiana T

2016-01-01

Naming pictures and matching words to pictures belonging to the same semantic category impairs performance relative to when stimuli come from different semantic categories (i.e., semantic interference). Despite similar semantic interference phenomena in both picture naming and word-picture matching tasks, the locus of interference has been attributed to different levels of the language system - lexical in naming and semantic in word-picture matching. Although both tasks involve access to shared semantic representations, the extent to which interference originates and/or has its locus at a shared level remains unclear, as these effects are often investigated in isolation. We manipulated semantic context in cyclical picture naming and word-picture matching tasks, and tested whether factors tapping semantic-level (generalization of interference to novel category items) and lexical-level processes (interactions with lexical frequency) affected the magnitude of interference, while also assessing whether interference occurs at a shared processing level(s) (transfer of interference across tasks). We found that semantic interference in naming was sensitive to both semantic- and lexical-level processes (i.e., larger interference for novel vs. old and low- vs. high-frequency stimuli), consistent with a semantically mediated lexical locus. Interference in word-picture matching exhibited stable interference for old and novel stimuli and did not interact with lexical frequency. Further, interference transferred from word-picture matching to naming. Together, these experiments provide evidence to suggest that semantic interference in both tasks originates at a shared processing stage (presumably at the semantic level), but that it exerts its effect at different loci when naming pictures vs. matching words to pictures.

Imperfect generalized transmit beamforming with co-channel interference cancelation

KAUST Repository

Radaydeh, Redha Mahmoud Mesleh; Alouini, Mohamed-Slim

2010-01-01

of outdated statistical ordering of the interferers instantaneous powers on the effectiveness of dominant interference cancelation is investigated against the less complex adaptive arbitrary cancelation scheme. For the system models described above, new exact

[Influences of balancing-side interference on jaw function].

Science.gov (United States)

Baba, K

1991-03-01

The influences of experimental balancing-side interference on the jaw function were investigated on 6 subjects. A specially designed onlay was fabricated for the lower second molar, which acted as an artificial balancing-side interference in the lateral mandibular position. The subjects were asked to do maximum clenching, lateral gliding and gum chewing with and without the device. Electromyographic activity of the masseter and the anterior and posterior temporal muscles were measured and the related mandibular movement was simultaneously recorded during these tasks. Introduction of the experimental interference caused alteration in the muscle activity as follows: 1. When the subjects exerted maximum clenching efforts in the lateral mandibular position, the ratio of the temporal muscle activity on the working-side to the balancing-side decreased, while that of the masseter muscle remained unchanged. 2. There was a tendency for the activity in the working-side posterior temporal muscle to increase during gliding from intercuspation. The ratio of the temporal muscle activity on the working-side to the balancing-side decreased during gliding into intercuspation. 3. Prolongation of the occlusal phase associated with the increase of the muscle activity was observed during gum chewing on the side opposite to the interference. It was suggested that the balancing-side interference might provoke a specific muscle activity in the temporal muscles during parafunctional clenching or grinding.

Interference effects of categorization on decision making.

Science.gov (United States)

Wang, Zheng; Busemeyer, Jerome R

2016-05-01

Many decision making tasks in life involve a categorization process, but the effects of categorization on subsequent decision making has rarely been studied. This issue was explored in three experiments (N=721), in which participants were shown a face stimulus on each trial and performed variations of categorization-decision tasks. On C-D trials, they categorized the stimulus and then made an action decision; on X-D trials, they were told the category and then made an action decision; on D-alone trials, they only made an action decision. An interference effect emerged in some of the conditions, such that the probability of an action on the D-alone trials (i.e., when there was no explicit categorization before the decision) differed from the total probability of the same action on the C-D or X-D trials (i.e., when there was explicit categorization before the decision). Interference effects are important because they indicate a violation of the classical law of total probability, which is assumed by many cognitive models. Across all three experiments, a complex pattern of interference effects systematically occurred for different types of stimuli and for different types of categorization-decision tasks. These interference effects present a challenge for traditional cognitive models, such as Markov and signal detection models, but a quantum cognition model, called the belief-action entanglement (BAE) model, predicted that these results could occur. The BAE model employs the quantum principles of superposition and entanglement to explain the psychological mechanisms underlying the puzzling interference effects. The model can be applied to many important and practical categorization-decision situations in life. Copyright © 2016 Elsevier B.V. All rights reserved.

Quantum Erasure: Quantum Interference Revisited

OpenAIRE

Walborn, Stephen P.; Cunha, Marcelo O. Terra; Pádua, Sebastião; Monken, Carlos H.

2005-01-01

Recent experiments in quantum optics have shed light on the foundations of quantum physics. Quantum erasers - modified quantum interference experiments - show that quantum entanglement is responsible for the complementarity principle.

Release from Proactive Interference: Insufficiency of an Attentional Account

Science.gov (United States)

MacLeod, Colin M.

1975-01-01

If an attentional cue affects retroactive interference, perhaps a similar mechanism underlies release from proactive interference. This study tested this hypothesis by inserting an attentional cue before the final trial in Wickens' paradigm. (Author/RK)

Time and interference: Effects on working memory.

Science.gov (United States)

Botto, Marta; Palladino, Paola

2016-05-01

This study tested predictions from the time-based resource-sharing (TBRS) model with a classical verbal working memory (WM) task, where target and non-target information interfere strongly with each other. Different predictions can be formulated according to the dominant perspectives (TBRS and interference hypothesis) on the role of inhibitory control in WM task performance. Here, we aimed to trace the activation of irrelevant information, examining priming effects in a lexical decision task immediately following WM recall. Results indicate the roles of both time and interference constraints in determining task performance. In particular, the role of time available seemed crucial at the highest WM loads (i.e., 3 and 4 memoranda). These were also associated with a higher activation of no-longer-relevant information but, in this case, independently from time available for processing. © 2015 The British Psychological Society.

Interference Mitigation Technique for Coexistence of Pulse-Based UWB and OFDM

Directory of Open Access Journals (Sweden)

Ohno Kohei

2008-01-01

Full Text Available Abstract Ultra-wideband (UWB is a useful radio technique for sharing frequency bands between radio systems. It uses very short pulses to spread spectrum. However, there is a potential for interference between systems using the same frequency bands at close range. In some regulatory systems, interference detection and avoidance (DAA techniques are required to prevent interference with existing radio systems. In this paper, the effect of interference on orthogonal frequency division multiplexing (OFDM signals from pulse-based UWB is discussed, and an interference mitigation technique is proposed. This technique focuses on the pulse repetition cycle of UWB. The pulse repetition interval is set the same or half the period of the OFDM symbol excluding the guard interval to mitigate interference. These proposals are also made for direct sequence (DS-UWB. Bit error rate (BER performance is illustrated through both simulation and theoretical approximations.

Interference-aware random beam selection schemes for spectrum sharing systems

KAUST Repository

Abdallah, Mohamed

2012-10-19

Spectrum sharing systems have been recently introduced to alleviate the problem of spectrum scarcity by allowing secondary unlicensed networks to share the spectrum with primary licensed networks under acceptable interference levels to the primary users. In this work, we develop interference-aware random beam selection schemes that provide enhanced performance for the secondary network under the condition that the interference observed by the receivers of the primary network is below a predetermined/acceptable value. We consider a secondary link composed of a transmitter equipped with multiple antennas and a single-antenna receiver sharing the same spectrum with a primary link composed of a single-antenna transmitter and a single-antenna receiver. The proposed schemes select a beam, among a set of power-optimized random beams, that maximizes the signal-to-interference-plus-noise ratio (SINR) of the secondary link while satisfying the primary interference constraint for different levels of feedback information describing the interference level at the primary receiver. For the proposed schemes, we develop a statistical analysis for the SINR statistics as well as the capacity and bit error rate (BER) of the secondary link.

Reading a Story: Different Degrees of Learning in Different Learning Environments

Directory of Open Access Journals (Sweden)

Anna Maria Giannini

2017-10-01

Full Text Available The learning environment in which material is acquired may produce differences in delayed recall and in the elements that individuals focus on. These differences may appear even during development. In the present study, we compared three different learning environments in 450 normally developing 7-year-old children subdivided into three groups according to the type of learning environment. Specifically, children were asked to learn the same material shown in three different learning environments: reading illustrated books (TB; interacting with the same text displayed on a PC monitor and enriched with interactive activities (PC-IA; reading the same text on a PC monitor but not enriched with interactive narratives (PC-NoIA. Our results demonstrated that TB and PC-NoIA elicited better verbal memory recall. In contrast, PC-IA and PC-NoIA produced higher scores for visuo-spatial memory, enhancing memory for spatial relations, positions and colors with respect to TB. Interestingly, only TB seemed to produce a deeper comprehension of the story’s moral. Our results indicated that PC-IA offered a different type of learning that favored visual details. In this sense, interactive activities demonstrate certain limitations, probably due to information overabundance, emotional mobilization, emphasis on images and effort exerted in interactive activities. Thus, interactive activities, although entertaining, act as disruptive elements which interfere with verbal memory and deep moral comprehension.

Reading a Story: Different Degrees of Learning in Different Learning Environments.

Science.gov (United States)

Giannini, Anna Maria; Cordellieri, Pierluigi; Piccardi, Laura

2017-01-01

The learning environment in which material is acquired may produce differences in delayed recall and in the elements that individuals focus on. These differences may appear even during development. In the present study, we compared three different learning environments in 450 normally developing 7-year-old children subdivided into three groups according to the type of learning environment. Specifically, children were asked to learn the same material shown in three different learning environments: reading illustrated books (TB); interacting with the same text displayed on a PC monitor and enriched with interactive activities (PC-IA); reading the same text on a PC monitor but not enriched with interactive narratives (PC-NoIA). Our results demonstrated that TB and PC-NoIA elicited better verbal memory recall. In contrast, PC-IA and PC-NoIA produced higher scores for visuo-spatial memory, enhancing memory for spatial relations, positions and colors with respect to TB. Interestingly, only TB seemed to produce a deeper comprehension of the story's moral. Our results indicated that PC-IA offered a different type of learning that favored visual details. In this sense, interactive activities demonstrate certain limitations, probably due to information overabundance, emotional mobilization, emphasis on images and effort exerted in interactive activities. Thus, interactive activities, although entertaining, act as disruptive elements which interfere with verbal memory and deep moral comprehension.

Enhanced eyeblink conditioning in behaviorally inhibited individuals is disrupted by proactive interference following US alone pre-exposures.

Directory of Open Access Journals (Sweden)

Michael Todd Allen

2016-03-01

Full Text Available Anxiety vulnerable individuals exhibit enhanced acquisition of conditioned eyeblinks as well as enhanced proactive interference from CS or US alone pre-exposures (Holloway et al., 2012. US alone pre-exposures disrupt subsequent CR acquisition to CS-US paired trials as compared to context pre-exposure controls. While Holloway et al., (2012 reported enhanced acquisition in high trait anxiety individuals in the context condition, anxiety vulnerability effects were not reported for the US alone pre-exposure group. It appears from the published data that there were no differences between high and low anxiety individuals in the US alone condition. In the work reported here, we sought to extend the findings of enhanced proactive interference with US alone pre-exposures to determine if the enhanced conditioning was disrupted by proactive interference procedures. We also were interested in the spontaneous eyeblinks during the pre-exposure phase of training. We categorized individuals as anxiety vulnerability or non-vulnerable individuals based scores on the Adult Measure of Behavioural Inhibition (AMBI. Sixty six participants received 60 trials consisting of 30 US alone or context alone pre-exposures followed by 30 CS-US trials. US alone pre-exposures not only disrupted CR acquisition overall, but behaviorally inhibited (BI individuals exhibited enhanced proactive interference as compared to non-inhibited (NI individuals. In addition, US alone pre-exposures disrupted the enhanced acquisition observed in BI individuals as compared to NI individuals following context alone pre-exposures. Differences were also found in rates of spontaneous eyeblinks between BI and NI individuals during context pre-exposure. Our findings will be discussed in the light of the neural substrates of eyeblink conditioning as well as possible factors such as hypervigilance in the amygdala and hippocampal systems, and possible learned helplessness. Applications of these findings of

Enhanced Eyeblink Conditioning in Behaviorally Inhibited Individuals is Disrupted by Proactive Interference Following US Alone Pre-exposures.

Science.gov (United States)

Allen, Michael Todd; Miller, Daniel P

2016-01-01

learned helplessness. Applications of these findings of enhanced proactive interference in BI individuals to pre-exposure therapies to reduce anxiety disorders such as posttraumatic stress disorder (PTSD) will be discussed.

Improved contrast polymer light-emitting diode with optical interference layers

International Nuclear Information System (INIS)

Liu, H.Y.; Sun, R.G.; Yang, K.X.; Peng, J.B.; Cao, Y.; Joo, S.K.

2007-01-01

An improved contrast polymer light diode based on the destructive optical interference layers deposited between the glass substrate and ITO anode is fabricated. It is unnecessary to be considered that the additional optical interference structure will impede carrier injection from the electrode to the carrier-transporting layer. Due to the quarter-wavelength thickness of medial ITO layer, the reflected light from first Cr layer is inverted 180 o out of phase with the reflected light from second Cr layer, resulting in the destructive interference. It is evident that the contrast ratio of the device with the optical interference structure is about three times higher than that of the conventional device

Cognitive interference modeling with applications in power and admission control

KAUST Repository

Mahmood, Nurul Huda

2012-10-01

One of the key design challenges in a cognitive radio network is controlling the interference generated at coexisting primary receivers. In order to design efficient cognitive radio systems and to minimize their unwanted consequences, it is therefore necessary to effectively control the secondary interference at the primary receivers. In this paper, a generalized framework for the interference analysis of a cognitive radio network where the different secondary transmitters may transmit with different powers and transmission probabilities, is presented and various applications of this interference model are demonstrated. The findings of the analytical performance analyses are confirmed through selected computer-based Monte-Carlo simulations. © 2012 IEEE.

Trajectory description of the quantum–classical transition for wave packet interference

Energy Technology Data Exchange (ETDEWEB)

Chou, Chia-Chun, E-mail: ccchou@mx.nthu.edu.tw

2016-08-15

The quantum–classical transition for wave packet interference is investigated using a hydrodynamic description. A nonlinear quantum–classical transition equation is obtained by introducing a degree of quantumness ranging from zero to one into the classical time-dependent Schrödinger equation. This equation provides a continuous description for the transition process of physical systems from purely quantum to purely classical regimes. In this study, the transition trajectory formalism is developed to provide a hydrodynamic description for the quantum–classical transition. The flow momentum of transition trajectories is defined by the gradient of the action function in the transition wave function and these trajectories follow the main features of the evolving probability density. Then, the transition trajectory formalism is employed to analyze the quantum–classical transition of wave packet interference. For the collision-like wave packet interference where the propagation velocity is faster than the spreading speed of the wave packet, the interference process remains collision-like for all the degree of quantumness. However, the interference features demonstrated by transition trajectories gradually disappear when the degree of quantumness approaches zero. For the diffraction-like wave packet interference, the interference process changes continuously from a diffraction-like to collision-like case when the degree of quantumness gradually decreases. This study provides an insightful trajectory interpretation for the quantum–classical transition of wave packet interference.

Interference in wireless ad hoc networks with smart antennas

KAUST Repository

Alabdulmohsin, Ibrahim

2014-01-01

In this paper, we show that the use of directional antennas in wireless ad hoc networks can actually increase interference due to limitations of virtual carrier sensing. We derive a simple mathematical expression for interference in both physical

On full duplex Gaussian relay channels with self-interference

KAUST Repository

Behboodi, Arash; Chaaban, Anas; Mathar, Rudolf; Alouini, Mohamed-Slim

2016-01-01

Self interference (SI) in full duplex (FD) systems is the interference caused by the transmission stream on the reception stream. Being one of the main restrictive factors for performance of practical full duplex systems, however, not too much

Performance comparison of optical interference cancellation system architectures.

Science.gov (United States)

Lu, Maddie; Chang, Matt; Deng, Yanhua; Prucnal, Paul R

2013-04-10

The performance of three optics-based interference cancellation systems are compared and contrasted with each other, and with traditional electronic techniques for interference cancellation. The comparison is based on a set of common performance metrics that we have developed for this purpose. It is shown that thorough evaluation of our optical approaches takes into account the traditional notions of depth of cancellation and dynamic range, along with notions of link loss and uniformity of cancellation. Our evaluation shows that our use of optical components affords performance that surpasses traditional electronic approaches, and that the optimal choice for an optical interference canceller requires taking into account the performance metrics discussed in this paper.

The Impact of Radio Interference on Future Radio Telescopes

Science.gov (United States)

Mitchell, Daniel A.; Robertson, Gordon J.; Sault, Robert J.

While future radio telescopes will require technological advances from the communications industry interference from sources such as satellites and mobile phones is a serious concern. In addition to the fact that the level of interference is growing constantly the increased capabilities of next generation instruments make them more prone to harmful interference. These facilities must have mechanisms to allow operation in a crowded spectrum. In this report some of the factors which may limit the effectiveness of these mechanisms are investigated. Radio astronomy is unique among other observing wavelengths in that the radiation can be fully sampled at a rate which completely specifies the electromagnetic environment. Knowledge of phases and antennae gain factors affords one the opportunity to attempt to mitigate interference from the astronomical data. At present several interference mitigation techniques have been demonstrated to be extremely effective. However the observational scales of the new facilities will push the techniques to their limits. Processes such as signal decorrelation varying antenna gain and instabilities in the primary beam will have a serious effect on some of the algorithms. In addition the sheer volume of data produced will render some techniques computationally and financially impossible.

Conducted Interference Immunity Characteristics to High-speed Power Line Communication System

Science.gov (United States)

Tokuda, Masamitsu; Hosoya, Satoshi; Yamagata, Toru; Matsuo, Takashi

In this paper, we measured the immunity characteristics to the conducted interference wave, from the aspect of PHY rate (physical layer data rate) of PLC (Power Line Communication) system, and compared with simulation results by MATLAB/ Simulink. When the interference signal is impressed to the OFDM (Orthogonal Frequency Division Multiplexing) signal, the PHY rate decrease rapidly below C/I (Carrier / Interference) = 25dB and become nearly zero around C/I = -35dB, and so it turns out that the PLC System with OFDM signal has a good narrowband interference immunity characteristic. In addition, it is revealed that the PHY rate of PLC modem can be calculated by MATLAB/Simulink even when the narrowband interference signal is impressed through the power line. Furthermore, we examined the improving effect of the notch band for the immunity characteristics to the conducted interference wave. As a result, it is revealed that the PHY rate normalized by the maximum value increases by 15∼25% by inserting the notch when impressing the interference signal in the notch band and C/I is improved by 10∼15dB by inserting the notch.

Interference fits and stress-corrosion failure. [aircraft parts fatigue life analysis

Science.gov (United States)

Hanagud, S.; Carter, A. E.

1976-01-01

It is pointed out that any proper design of interference fit fastener, interference fit bushings, or stress coining processes should consider both the stress-corrosion susceptibility and fatigue-life improvement together. Investigations leading to such a methodology are discussed. A service failure analysis of actual aircraft parts is considered along with the stress-corrosion susceptibility of cold-working interference fit bushings. The optimum design of the amount of interference is considered, giving attention to stress formulas and aspects of design methodology.

Entanglement detection from interference fringes in atom-photon systems

International Nuclear Information System (INIS)

Suzuki, Jun; Nemoto, Kae; Miniatura, Christian

2010-01-01

A measurement scheme of atomic qubits pinned at given positions is studied by analyzing the interference pattern obtained when they emit photons spontaneously. In the case of two qubits, a well-known relation is revisited in which the interference visibility is equal to the concurrence of the state in the infinite spatial separation limit of the qubits. By taking into account the superradiant and subradiant effects, it is shown that a state tomography is possible when the qubit spatial separation is comparable to the wavelength of the atomic transition. In the case of three qubits, the relations between various entanglement measures and the interference visibility are studied, where the visibility is defined from the two-qubit case. A qualitative correspondence among these entanglement relations is discussed. In particular, it is shown that the interference visibility is directly related to the maximal bipartite negativity.

Chemical control of channel interference in two-photon absorption processes.

Science.gov (United States)

Alam, Md Mehboob; Chattopadhyaya, Mausumi; Chakrabarti, Swapan; Ruud, Kenneth

2014-05-20

The two-photon absorption (TPA) process is the simplest and hence the most studied nonlinear optical phenomenon, and various aspects of this process have been explored in the past few decades, experimentally as well as theoretically. Previous investigations have shown that the two-photon (TP) activity of a molecular system can be tuned, and at present, performance-tailored TP active materials are easy to develop by monitoring factors such as length of conjugation, dimensionality of charge-transfer network, strength of donor-acceptor groups, polarity of solvents, self-aggregation, H-bonding, and micellar encapsulation to mention but a few. One of the most intriguing phenomena affecting the TP activity of a molecule is channel interference. The phrase "channel interference" implies that if the TP transition from one electronic state to another involves more than one optical pathway or channel, characterized by the corresponding transition dipole moment (TDM) vectors, the channels may interfere with each other depending upon the angles between the TDM vectors and hence can either increase (constructive interference) or decrease (destructive interference) the overall TP activity of a system to a significant extent. This phenomenon was first pointed out by Cronstrand, Luo, and Ågren [Chem. Phys. Lett. 2002, 352, 262-269] in two-dimensional systems (i.e., only involving two components of the transition moment vectors). For three-dimensional molecules, an extended version of this idea was required. In order to fill this gap, we developed a generalized model for describing and exploring channel interference, valid for systems of any dimensionality. We have in particular applied it to through-bond (TB) and through-space (TS) charge-transfer systems both in gas phase and in solvents with different polarities. In this Account, we will, in addition to briefly describing the concept of channel interference, discuss two key findings of our recent work: (1) how to control the

Interference-aware random beam selection for spectrum sharing systems

KAUST Repository

Abdallah, Mohamed M.; Sayed, Mostafa M.; Alouini, Mohamed-Slim; Qaraqe, Khalid A.

2012-01-01

. In this paper, we develop interference-aware random beam selection schemes that provide enhanced throughput for the secondary link under the condition that the interference observed at the primary link is within a predetermined acceptable value. For a secondary

Repetitive Transcranial Magnetic Stimulation to the Primary Motor Cortex Interferes with Motor Learning by Observing